WO1998006012A1

WO1998006012A1 - Image forming apparatus and image forming method

Info

Publication number: WO1998006012A1
Application number: PCT/JP1997/002734
Authority: WO
Inventors: Yoshihiro Makuta; Toyoko Imai
Original assignee: Nippon Zeon Co., Ltd.
Priority date: 1996-08-06
Filing date: 1997-08-06
Publication date: 1998-02-12

Abstract

A toner image is formed on an electrophotograph photosensitive body by a developing means in which toner powder is stored. The toner image is transferred onto a transfer material and the image is outputted. The toner powder which remains on the electrophotograph photosensitive body after the transfer is recovered by the developing means which also functions as a cleaning means. The material of the surface of the electrophotograph photosensitive body is positive-chargeable organic photosensitive material which contains a phthalocyanine compound as a charge generating agent, a diphenoquinone compound as an electron transporting agent and a nitrogen-containing polyaromatic cyclic compound as a positive hole transporting agent. The toner powder has a sphericity which is calculated by dividing the area (Sc) of a circle whose diameter is the absolutely maximum length of the particles by the actual projection area (Sr) of the particles, within a range of 1.0-1.3 and is colored polymer particles produced by a suspension polymerization method.

Description

Specification

Image forming apparatus and image forming method

Technical field

The present invention relates to an image forming apparatus and an image forming method using an electrophotographic method, such as an electrophotographic copying machine, and more particularly, recovers residual toner particles on a photoconductor at the same time as an image is developed by a developing unit. The present invention relates to a cleaner-less image forming apparatus or image forming method, which relates to a novel image forming apparatus and an image forming method which have high image density, exhibit stable image quality, and suppress generation of ozone. .

Background art

2. Description of the Related Art Generally, an image forming apparatus using an electrophotographic method, such as an electrophotographic copying machine, is an electrophotographic photoconductor (also referred to as a latent image carrier or a photoconductor drum. A charging means for uniformly and uniformly charging the surface of the photoreceptor, a latent image forming means such as a laser device for writing an electrostatic latent image on the surface of the charged photoreceptor (that is, an exposure means), Developing means for developing the electrostatic latent image with a developer (also simply referred to as toner or toner particles); transfer means for transferring the developed toner image to a transfer material such as transfer paper; and residual toner particles on the photoreceptor. It is equipped with cleaning means for removal.

Examples of the developer include a one-component developer consisting essentially of only toner particles and a two-component developer consisting of toner particles and carrier particles. The one-component developer includes a magnetic one-component developer containing magnetic powder and a non-magnetic one-component developer containing no magnetic powder. Non-magnetic one-component developer In many cases, a fluidizing agent is externally added. The toner particles are colored particles obtained by adding a colorant and other additives to a binder resin.

The toner particles are prepared by a method (pulverization method) in which (1) a synthetic resin, a colorant, and various additives are melt-kneaded, then pulverized, and then classified into a desired particle size (pulverization method). A method of suspension polymerizing the produced colored resin particles and (2) a polymerizable monomer composition containing a polymerizable monomer, a colorant, and various additives in an aqueous suspension medium (suspension). Polymerized polymer particles). In the present invention, the developer may be simply referred to as a toner particle which is a main component thereof.

FIG. 2 shows a cross-sectional view of an example of a conventional image forming apparatus. The image forming apparatus includes a photosensitive member 201, a cleaning means 202 having a cleaning blade 202a disposed around the photosensitive member 201, and a charging means 2. 0, exposure means 204, developing means 205, transfer means 206, and the like. Image exposure is performed by the exposure means 204 on the photoreceptor uniformly and uniformly charged by the charging means 203 to form an electrostatic latent image. The electrostatic latent image is developed with developer (toner particles) 210 using developing means ^ J_. The toner image developed on the photoconductor 201 is transferred onto the transfer material 207 by the transfer means 206. After the transfer step, the toner particles remaining on the photosensitive body 201 are removed by the cleaning means 202 to prepare for the next latent image formation. The toner image transferred onto the transfer material 2007 is fixed on the transfer material by a method such as heating by fixing means (not shown).

In general, a photoreceptor whose surface material is an organic photoreceptor, an amorphous silicon, a selenium-based photoreceptor, or the like is used. Among these, a photoreceptor having a structure in which an organic photoreceptor layer is formed on a conductive substrate is widely used from the viewpoint of sensitivity and strength. Charging means For example, a charger that performs corona discharge (also referred to as a charger liner, a corona charger, or a corona discharge device) is used as 203. Have been. In a charge line device, a voltage of several kV is applied to a discharge wire surrounded by a grounded shield plate to cause a corona discharge, and the surface of the photoreceptor is uniformly and uniformly exposed to the generated ions. Is charged in a similar manner. The developing means 205 acts to attach toner particles to the electrostatic latent image formed on the photoconductor 201. There are various developing methods and developing means. The developing means 205 shown in FIG. 2 includes a developing roller 209, a blade 209 for a current roller, and a means for accommodating a developer (toner-particle) 210 (that is, an accommodating container). —Singing) 2 1 1, and a developer supply means (that is, a developer supply roller) 2 1 2. The developing roller 208 is arranged so as to face the photoconductor 201. The developing roller 208 is usually arranged close to the photoconductor 201 so that a part thereof is in contact with the photoconductor 201, and is rotated in a direction opposite to the photoconductor 201. Can be The developer supply roller 211 is configured to contact the developing roller 208 and rotate in the same direction as the developer opening roller 208, and is arranged on the outer peripheral surface of the developing roller 208. It serves to supply the toner particles 210. When the developing roller 208 is rotated in the developing device, the toner particles 210 in the developer accommodating means 211 adhere to the outer peripheral surface of the developing roller due to electrostatic force or the like due to friction. The developing roller blade 209 comes into contact with the outer peripheral surface of the developing roller 208 to be tillage, and adjusts and passes the thickness of the toner particle layer formed on the outer peripheral surface of the developing roller 208. It acts to equalize the charge amount of the toner particles. In the reversal development method, toner particles are attached only to the light-irradiated part (exposed part) of the photoconductor 201, while in the regular development method, only the light-irradiated part (unexposed part) is applied. Develop roller 208 and photoconductor so that toner particles adhere. It is configured so that a bias voltage is applied between the input and output terminals. Part of the toner particles adhered to the outer peripheral surface of the developing roller 208 are disturbed by the pattern of the electrostatic latent image when the surface of the developing roller 208 approaches the surface of the photoconductor 201. The photosensitive member 201 selectively moves to the surface of the photosensitive member 201 as described above, whereby the electrostatic latent image on the photosensitive member 201 is developed to form a toner image (visible image). This toner image is transferred to the transfer material 207, and an image is formed on the transfer material. The transfer means 206 shown in Fig. 2 consists of a charger that performs corona discharge. The transfer material is superimposed on the toner image, and is charged from the back of the transfer material to the polarity opposite to the polarity of the toner particles. As a result, the toner image on the photoconductor 201 is transferred onto the transfer material 207. The toner particles remaining on the photoreceptor 201 are wiped off with an edge of a blade 202 a of the cleaning means 202 to prepare for the next latent image forming step. The toner image transferred onto the transfer material 2007 is fixed by fixing means (not shown). As a fixing means, generally, a heating roller or a belt is used, and the toner particles are fixed to the transfer material by heat fusion.

Such an image forming apparatus and an image forming method have the following problems.

(1) When a charger (charger device) for performing corona discharge as shown in FIG. 2 is used as the charging means 203, there is a problem that ozone is generated. In particular, when negative polarity corona discharge is used by using a negatively charged organic photosensitive material that is practically used, the amount of ozone generated increases. Ozone is not only harmful to human health but also has a strong odor, which causes a deterioration in the working environment. Conventionally, in order to solve this problem, a method has been proposed in which a charging roller is used instead of the charge and discharge device. However, the charging roller contacts the photoconductor. It is difficult to select the material and control the process for uniform charging, and it also causes problems such as fogging due to toner particles adhering to the charging roller due to contact, and charging roller rubber. There is a possibility that a contamination problem of the photoconductor may occur due to the compounding agent contained in the elastic layer. Also, the cost of the charging roller is higher than that of the charge wire device.

(2) After the transfer step, the residual toner particles on the photoreceptor are removed by a cleaning blade, but the photoreceptor is damaged by the contact at that time. In addition, the residual toner particles on the photoreceptor are easily crushed by contact with the cleaning blade, and when the residual toner particles are crushed, a charge controlling agent existing on the fracture surface thereof, a release agent, Filming due to adhesion of coloring agents, coloring agents, etc. occurs on the photoconductor. The toner particles circulated in the image forming process are subjected to a long-term stress between the cleaning blade and the photoreceptor, and as a result, the toner particles are turned into fine particles and charged. Failure is easy to occur. In addition, a rubber blade is usually used as a cleaning blade, but a cleaning failure is likely to occur due to the aging of the rubber over time.

(3) In recent years, a method has been proposed in which a developing means is used to collect residual toner particles on a photoconductor at the same time as development without using a cleaning means. That is, a developing roller carrying a toner particle layer charged to the same polarity as the electrostatic latent image on the photoconductor is arranged to face the photoconductor, and the latent image area on the photoconductor is formed on the developing roller. At the same time as developing with toner particles, cleaning is performed by suctioning and removing residual toner particles after transfer adhering to the non-latent image area on the photoreceptor to the developing roller side. However, this simultaneous development and cleaning method requires a large amount of toner particles remaining on the photoreceptor after transfer, resulting in insufficient cleaning and positive ghosting (that is, the previously printed image). Is a new print image The phenomenon occurs when printing is overlaid on the image). Therefore, it is necessary to increase the transfer efficiency of the toner particles. Disclosure of the invention

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus provided with a cleaner-less device that collects toner particles remaining on a photoreceptor at the same time as development by a developing unit, and has high image density and stable image quality. Another object of the present invention is to provide a novel image forming apparatus which suppresses the generation of ozone.

Another object of the present invention is to provide an image forming method using a cleaner-less method in which residual toner particles on a photoreceptor are collected simultaneously with development by a developing means. An object of the present invention is to provide an image forming method which shows stable image quality and suppresses ozone generation.

Another object of the present invention is to provide toner particles used in an image forming method by a cleaner-less method in which residual toner particles on a photoreceptor are collected simultaneously with development by a developing means. .

The present inventors have conducted intensive studies to overcome the above-mentioned problems of the prior art. (1) As an electrophotographic photoreceptor, a positively chargeable organic photoreceptor layer having a specific composition is formed on a conductive substrate. And (2) spherical toner particles having a sphericity of 1.0 to 1.3 generated by the polymerization method are used, and a charging device as a charging device is used. Ozone generation can be suppressed even by using, and high-quality images can be formed without damaging the photoreceptor even if cleaning is performed simultaneously with development by a cleanerless method. Was found. The present invention has been completed based on these findings.

According to the present invention, a toner image is formed on an electrophotographic photosensitive member by a developing means containing toner particles, and the toner image is transferred onto a transfer material. In the image forming apparatus, the developing means also serves as a cleaning means for outputting an image and recovering post-transfer residual toner particles attached to the electrophotographic photosensitive member.

(1) The surface material of the electrophotographic photoreceptor is a phthalocyanine compound as a charge generating agent, a diphnoquinone compound as an electron transporting agent, and a nitrogen-containing compound as a hole transporting agent. A positively chargeable organic photoreceptor containing a polyaromatic compound, and

(2) The toner particles have a sphericity of 1.0 to 1.3 obtained by dividing the area (Sc) of a circle whose diameter is the absolute maximum length of the particles by the real projected area (Sr) of the particles. Colored polymer particles within the range and produced by the suspension polymerization method

An image forming apparatus characterized by the above is provided.

Further, according to the present invention, a developer carrying a toner particle layer is disposed so as to face an electrophotographic photoreceptor, and a latent image area on the photoreceptor is covered with toner particles on the developer orifice. In the image forming method, cleaning is performed by suctioning and removing toner particles remaining after transfer adhering to the non-latent image area on the photoreceptor to the developing opening side at the same time.

(1) An electrophotographic photoreceptor whose surface material is a phthalocyanine compound as a charge generator, a diphenylquinone compound as an electron transport agent, and a hole transport agent A positively chargeable organic photoreceptor containing a nitrogen-containing polyaromatic compound is used, and

(2) For toner particles, the sphericity obtained by dividing the area (Sc) of a circle whose diameter is the absolute maximum length of the particle by the real projected area (Sr) of the particle is 1.0 to 1 Use colored polymer particles that fall within the range of 3 and that are produced by a suspension polymerization method.

An image forming method characterized by this is provided. Further, according to the present invention, as an electrophotographic photoreceptor, the material on the surface thereof is a phthalocyanine-based compound as a charge generating agent, and a diphnoquinone-based compound as an electron transporting agent. A positively chargeable organic photoreceptor containing a compound and a nitrogen-containing polyaromatic compound as a hole transporting agent is used, and a developing roller carrying a toner particle layer is arranged to face the photoreceptor. Then, the latent image area on the photoconductor is developed with toner particles on the developing roller, and at the same time, the residual toner particles after transfer adhering to the non-latent image area on the photoconductor are developed. Toner particles used in an image forming method including a method of performing cleaning by sucking and removing the toner particles on a side of the toner,

The sphericity obtained by dividing the area (S c) of the circle whose diameter is the absolute maximum length of the particle by the real projected area (S r) of the particle is in the range of 1.0 to 1.3, and Further, toner particles, which are colored polymer particles produced by a suspension polymerization method, are provided. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic diagram (cross-sectional view) of an example of an image forming apparatus used in the present invention.

FIG. 2 is a schematic diagram (cross-sectional view) of an example of a conventional image forming apparatus. FIG. 3 is a schematic diagram showing the effect of simultaneous development cleaning (cleaner-less method) in reversal development. BEST MODE FOR CARRYING OUT THE INVENTION

Electrophotographic photoreceptor>

In the present invention, the surface material of the electrophotographic photoreceptor is a phthalocyanine-based compound as a charge generating agent, a diphenylquinone-based compound as an electron transporting agent, and a hole ring. Including nitrogen-containing polyaromatic compounds as a transfer agent A positively chargeable organic photoreceptor having the above is used. Such an electrophotographic photoreceptor usually has an organic photoreceptor layer comprising a resin composition containing a charge generating agent, an electron transporting agent, a hole transporting agent, and a binder resin on a conductive substrate. It can be manufactured by providing.

As the charge generating agent, a phthalocyanine-based compound such as X-type metal free phthalocyanine or oxotitanylphthalocyanine is used. Examples of electron transporting agents include (A) 3,5—dimethyl-3 ′, 5′—di-tert-butyl-4,4′-diphenoquinone, 3,3′— Dimethylino 5, 5 '-Digital Principle 4, 4'-Diquinoquinone, 3, 5 'Dimethyl-3', 5-Diary 1 Butyl 4, 4 '-diphenoquinone; and (B) 3, 3', 5, 5 '-tetratary butyl 4, 4'-diphenoquinone, 3 , 3 ', 5, 5'-Tetrachinole 1, 4 '-Diphenoquinone, 3, 3', 5, 5 ' Use diphnoquinone-based compounds such as noquinone. These diquinoquinone-based compounds are generally 50 to 97% by weight of the compound (A), and the compounds (B) 3 to 3 have a larger absolute value of the reduction potential than the compound (A). 50% by weight is used together. The diphenoquinone-based compound (A) has good solubility in organic solvents and good compatibility with the binder resin. On the other hand, the diphenoquinone-based compound (B) has good electron injection efficiency because the absolute value of the reduction potential is large. Therefore, by using these diphenoquinone-based compounds (A) and (B) in the above-mentioned mixing ratio, an organic photoreceptor having a small residual potential and an improved sensitivity can be easily obtained. It can be formed. Each of these compounds belonging to the difunnoquinone compounds (A) and (B) can be used alone or in combination of two or more. Examples of hole transport agents include 3,3'-dimethyl-N, N, N ', N'-tetrakis (4-methylphenyl) 1,1,1'-biphenyl-14,4' Amin, 1, 1-bis (p—Jetylaminophenyl) 4,4'-diphenyl 1,3—butadiene, N, N'-bis (o, p—dimethinolephenyl ) 1 N, N '-diphenylbenzidine, N-ethyl-3-N-diphenyl hydrazone, N'-diphenylhydrazone, 41-(N, N-bis (p- Tonyl) amino] 1 ^ —phenyl stilbene, etc. Among them, nitrogen-containing polyaromatic compounds such as biphenyldiamine or phenylene Diamine compounds are preferred.

Examples of the binder resin for dispersing each of these components include polycarbonate, styrene-based polymer, acryl-based polymer, and styrene-acryl-based copolymer. , Ethylene vinyl acetate copolymer, Polypropylene, Ionomer, Polyvinyl chloride, Vinyl chloride-vinyl acetate copolymer, Polyester, Alkyl resin, Polyamide, Polyamide Polyurethane, epoxy resin, polyrelate, polysulfone, diarynolephate resin, silicone resin, ketone resin, polyvinyl butyral Examples include resin, polyether resin, phenol resin, and epoxy acrylate-based photocurable resin.

The mixing ratio of each component is usually 0.1 to 10 parts by weight of a charge generating agent, 0.1 to 80 parts by weight of an electron transporting agent, and holes with respect to 100 parts by weight of a binder resin. The transporting agent is 5 to 100 parts by weight. The binder resin and each component are organic solvents such as alcohols, aliphatic hydrocarbons, aromatic hydrocarbons, halogenated hydrocarbons, ethers, ketones, esters, dimethylformamide, and dimethylsulfoxide. It is used by dissolving or dispersing in water to prepare a coating solution. In addition to the above components, if necessary, oxidation prevention Agents, radical scavengers, singlet quencher, UV absorbers, softeners, surface modifiers, defoamers, lubricants, dispersion stabilizers, waxes, sceptors, donors, etc. it can.

The coating solution is applied on a conductive substrate to form an organic photoreceptor layer, and an electrophotographic photoreceptor whose surface is a positively chargeable organic photoreceptor is produced. Materials for the conductive substrate include aluminum, copper, tin, platinum, gold, silver, nickel, molybdenum, chrome, cadmium, titanium, and nickel. , Isomers, stainless steel, brass, and other simple metals; plastic materials on which these metals are deposited or laminated; and aluminum iodides. , Tin oxide, glass coated with indium oxide, and the like. As the conductive substrate, an aluminum tube is preferable, and an aluminum tube treated with alumite is particularly preferable. The thickness of the organic photoreceptor layer is usually from 5 to 100; um, preferably from 10 to 40 / m. This positively chargeable organic photoreceptor layer is a single layer.

In the present invention, as a toner particle (developer), the sphericity obtained by dividing the area (S c) of a circle having the absolute maximum length of the particle as the diameter by the substantial projected area (S r) of the particle is 1 Colored polymer particles in the range of 0 to 1.3 and produced by a suspension polymerization method are used. The colored polymer particles are spherical particles. The spherical toner particles are obtained by mixing a polymerizable monomer composition containing at least a polymerizable monomer and a colorant in an aqueous dispersion medium containing a dispersion stabilizer such as a poorly water-soluble metal compound. It can be suitably obtained by suspension polymerization.

Preferred toner particles include at least a binder resin and a colorant, and (1) have a volume average particle diameter (dV) of usually 1 to 50 m, preferably 2 to 15 m. Preferably between 3 and 10 m, (2) The ratio (dvZdn) of the volume average particle diameter (dv) to the number average particle diameter (dn) is 1.0 to 1.4, preferably 1.0 to 1.3,

(3) The area (Sc) obtained by dividing the area (Sc) of the circle, whose diameter is the absolute maximum length of the particle, by the real projected area (Sr) of the particle is 1.0 to 1.3, (4) BET specific surface area (A) (m ² / g), number average particle size (dn)

(m) and the product (A x d n x D) of the true specific gravity (D) are substantially spherical with 3 to 8,

(5) The absolute value of the ratio (QZA) between the charge amount (Q) (^ cZg) and the specific surface area (A) is in the range of 10 to 100

These are colored polymer particles.

By using a spherical toner having such characteristics, it is possible to form an image of good image quality without fogging of the photoreceptor even when the simultaneous cleaning method is used. You. Here, “fog” refers to a phenomenon in which toner particles adhere to a white background that is not a place where toner particles should originally be formed.

The method and apparatus for measuring physical properties of toner particles used in the present invention are as follows.

(1) The sphericity (ScSr) is a value obtained by taking an electron microscopic photograph of toner particles, measuring the photograph with an image processing analyzer under the following conditions, and analyzing the photograph.

• Image processing and analysis equipment: Luxx IID [Nicolet Co., Ltd.]

• Area ratio of particle to frame area: M a X 2%

• Total number of treated particles: 1 0 0 0

• The S c / S r value is indicated by the average number of 100 pieces.

(2) Specific surface area by BET method (A) is a value measured using an automatic specific surface area measuring apparatus type 2200 manufactured by Shimadzu Corporation. (3) The volume average particle size (dv) and number average particle size (dn) are values measured using a Coulter Counter (Model TA-II, manufactured by Nikkaki Co., Ltd.). .

(4) True specific gravity (D) is a value measured with a Beckman hydrometer. (5) Charge amount (Q) (〃 c Z g) Toner particles are blended with carrier TEFV150Z250 at a concentration of 5%, and stirred at 150 rpm for 30 minutes. After that, it is the value measured by the blow-off method. The charge amount (Q) and ratio (Q / A) are expressed as absolute values, regardless of whether the charge is positive or negative.

The toner particles used in the present invention can be obtained by polymerizing a polymerizable monomer composition containing at least a polymerizable monomer and a colorant by a suspension polymerization method. As the polymerizable monomer, a vinyl monomer is usually used. As a specific suspension polymerization method, for example, a vinyl monomer, a coloring agent, a radical polymerization initiator, and, if desired, various additives are uniformly dispersed by a mixer such as a ball mill. A homogeneous mixed solution (polymerizable monomer composition) is prepared, and then the uniform mixed solution is finely dispersed in an aqueous dispersion medium by high-shear stirring to form fine droplets. Thereafter, a method in which the temperature is usually raised to 30 to 200 to carry out suspension polymerization is mentioned. In suspension polymerization, a dispersion stabilizer is usually contained in the aqueous dispersion medium.

Examples of the vinyl monomer include aromatic vinyl such as styrene, vinyl toluene, and α-methylstyrene; acrylic acid, methacrylic acid, and methyl acrylate. , Ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethyl acrylate, ethyl methacrylate, ethyl methacrylate, methacrylic acid Pills, butyl methacrylate, 2-ethylhexyl methacrylate, dimethinorea methacrylate oleate, acrylonitrile, acrylonitrile, acrylamide, etc. Crylic acid or metaacrylic acid Derivatives; ethylene, propylene, butylene, etc .; olefins; vinyl chloride, vinylidene chloride, futsudani vinyl, etc .; halogenated vinyl; vinyl acetate, propionic acid Vinyl esters such as vinyl; vinyl ethers such as vinyl methyl ether and vinyl ethyl ether; vinyl ketones such as vinyl methyl ketone and methyl isopropenyl ketone; 2-vinyl pyridine; Nitrogen-containing vinyl compounds such as lysine and N-vinylpyrrolidone. Each of these vinyl monomers can be used alone or in combination of two or more.o

A crosslinkable monomer is preferably used as the polymerizable monomer together with these vinyl monomers. Examples of the crosslinkable monomer include aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene and derivatives thereof; ethylene glycol resin crelet, diethylene, and the like. Diethylenically unsaturated carboxylic acid esters such as glycol dimethacrylate; N, N—divinylaniline, divinyl ethers and other vinyl compounds, and three or more vinyl groups Can be listed. These crosslinkable monomers can be used alone or in combination of two or more.

Examples of the coloring agent include bonbon black, anilin black, crystal violent, loadamin B, malachite green, diglycine, and copper foil. Pigments and dyes such as rosinian and azo dyes can be mentioned. These colorants can be used alone or in combination of two or more.

In addition, nig mouth cin dye, quaternary ammonium salt, monoazo dye, metal-containing dye, zinc hexadecyl succinate, alkyl ester or alkyl amide of naphthoic acid, nitrofamic acid , N, N ' Polarity known as a charge control agent in this field, such as tramethinoresin benzophenone, N, N'-tetramethylbenzidine, triazine, salicylic acid metal complex, etc. One or more strong substances may be contained. By selecting the type of the charge controlling agent, it is also possible to adjust the electrode property of the toner particles to positive (+) or negative (1). In the present invention, since a positively chargeable organic photoreceptor is used, the toner particles are usually positively charged.

The toner particles can be internally or externally added with various additives for controlling chargeability, conductivity, fluidity, or adhesion to a photoreceptor or a fixing roller. You. Examples of such additives include release agents such as low-molecular-weight polypropylene, low-molecular-weight polyethylene, various plexes, silicone oil, carbon black, and carbonic acid. Inorganic fine powders such as calcium.

As the aqueous dispersion medium, water or an aqueous liquid containing water as a main component is used. Examples of the dispersion stabilizer include water-soluble polymers such as polyvinyl alcohol, methylcellulose, and gelatin; calcium phosphate, barium sulfate, calcium sulfate, and barium carbonate. Water-insoluble metal salts such as calcium carbonate, magnesium carbonate, etc .; inorganic polymer substances such as gay acid; metal oxides such as aluminum oxide and titanium oxide; aluminum hydroxide; Examples include metal hydroxides such as magnesium hydroxide and ferric hydroxide. Among these, in the aqueous phase of a poorly water-soluble metal hydroxide, particularly a water-soluble polyvalent metal salt (for example, magnesium chloride) and a hydroxylated alkali (for example, sodium hydroxide). It is preferable to use a poorly water-soluble metal hydroxide generated by the reaction in step (1). The dispersion stabilizer is used in a proportion of usually 0.1 to 20 parts by weight, preferably 0.5 to 18 parts by weight, based on 100 parts by weight of the aqueous dispersion medium. Examples of the polymerization initiator include, for example, t-butyl vinyl 2-ethyl hexanoate, succinic peroxide, t-hexyl peroxy 2-ethyl hexanoate, t Organic peroxides such as monobutyl peroxysobutyrate can be mentioned.

The ratio of the polymerizable monomer composition to the aqueous dispersion medium is not particularly limited.However, in consideration of the granulation stiffness and the dispersion stability of the particles during the polymerization reaction, the ratio of the polymerizable monomer is The concentration is usually about 5 to 50% by weight, preferably about 10 to 40% by weight.

After completion of the suspension polymerization reaction, the dispersion stabilizer remaining on the surface of the produced colored polymer particles is generally removed by pickling, washing with water, etc., followed by dehydration and drying. More toner particles (colored polymer particles) are recovered. The volume average particle size of the toner particles is usually 1 to 50 μm, preferably 2 to 15; ^ m, and more preferably 3 to 10 μm. Toner particles can be externally added with inorganic oxide particles such as colloidal ash as a fluidizing agent. The fluidizing agent adheres to the surface of the toner particles. Such toner particles and those obtained by externally adding a fluidizing agent to the toner particles can be used as a non-magnetic one-component developer.

In the apparatus and method of the present invention, a non-magnetic one-component developer as described above is preferably used, but if necessary, carrier particles are added to toner particles to form a two-component developer. Can also. If magnetic powder is contained in the polymerizable monomer composition during suspension polymerization, a magnetic one-component developer can be obtained. In any case, in the present invention, a developer containing, as an essential component, spherical toner particles obtained by a suspension polymerization method is used. Various components such as a fluidizing agent may be externally added to the toner particles.

Image forming apparatus and image forming method>

An image forming apparatus using electrophotography generally includes an electrophotographic photosensitive member, Charging means for charging the surface of the photoconductor, latent image forming means (exposure means) for writing an electrostatic latent image on the surface of the charged photoconductor, and developer (toner particles). A developing unit for developing the electrostatic latent image; and a transfer unit for transferring the developed toner image onto a transfer material.

FIG. 1 shows a sectional view of a specific example of the image forming apparatus of the present invention. In this image forming apparatus, a photoreceptor 1 as a latent image carrier is rotatably mounted in the direction of the arrow. The photoreceptor 1 is generally called a photoreceptor drum because of its shape. The photoreceptor 1 usually has a structure in which a positive band electroconductive organic photoreceptor layer (photoconductive layer) is provided on the outer periphery of a conductive substrate (support drum). Around the photoreceptor 1, a charging unit 3, a latent image forming unit 4, a developing unit and a transfer unit 6 are arranged along the circumferential direction. In the image forming apparatus of the present invention, there is no need to provide a cleaning means 202 as shown in FIG.

Generally, the charging means 3 has a function of uniformly or uniformly charging the surface of the photoconductor 1 positively or negatively. For example, the charging means 3 includes a corona discharge device, a charging roller, a charging blade, or the like. Be composed. In the present invention, the positively chargeable organic photoconductor layer on the surface of the photoconductor 1 is positively charged. As the charging means 3, a corona discharge device (charger wire device) is preferably used. The latent image forming means 4 irradiates light corresponding to an image signal onto the surface of the photoreceptor 1 uniformly and uniformly charged in a predetermined pattern to form an electrostatic latent image on an irradiated portion (reverse development (In the case of the normal development method) or forms an electrostatic latent image in the area where light is not irradiated (in the case of the normal development method). The latent image forming means 4 is composed of, for example, a combination of a laser device and an optical system, or a combination of an LED array and an optical system. The developing means A acts to attach toner particles to the electrostatic latent image formed on the surface of the photoconductor 1. The developing means is usually a developing roller 8, a developing roller blade 9, a housing means (housing case) 11 for toner particles 10, and a developer supply means (developer supply roller) 1 2 It is a developing device provided with. The developing roller 8 is arranged to face the photoconductor 1. The developing roller 8 is usually arranged close to the photoconductor 1 so that a part thereof contacts the surface of the photoconductor 1, and rotates in a direction opposite to the rotation direction of the photoconductor 1. The developer supply roller 12 is disposed in contact with the development roller 8 and rotates in the same direction as the development roller 8 to supply the toner particles 10 to the outer periphery of the development port roller 8. When the developing roller 8 is rotated in the developing device, the toner particles 10 in the developing agent containing means 11 adhere to the outer peripheral surface thereof due to electrostatic force or the like due to friction. The developing roller blade 9 is arranged in contact with the outer peripheral surface of the rotating developing roller 8 to adjust the thickness of the toner particle layer formed on the outer peripheral surface of the developing roller 8. In the reversal development method, toner particles adhere only to the light-irradiated part (exposed part) on the surface of the photoreceptor 1. On the other hand, in the regular development method, the toner particles adhere only to the light-irradiated part (unexposed part) A bias voltage is applied between the developing roller 8 and the photoreceptor 1 so that the toner adheres. The developing roller 8 is usually provided with a rubber elastic body (for example, styrene (butadiene rubber), acrylonitrile (butadiene rubber), epichloronore resin) on the outer periphery of the conductive shaft. Rubber, urethane rubber, silicone rubber, etc.). The developing roller blade 9 is usually made of a rubber elastic body as described above, but if necessary, contains conductive particles such as conductive carbon black to adjust the electric resistance value. I do.

The transfer means 6 is provided with a toner on the surface of the photoconductor 1 formed by the developing means 5. This is for transferring an image onto the transfer material 7 and includes, for example, a corona discharge device and a transfer roller. In the present invention, a transfer roller is preferably used as the transfer means 6.

To apply a cleaner-less system (simultaneous development cleaning system) that uses such an image forming apparatus and collects residual toner after development on the photoconductor at the same time as development by the developing means, It is preferable to adopt a method of performing reversal development under specific conditions.

Specific conditions in the reversal development system will be described below. The surface potential of the unexposed area (non-latent image area) on the surface of the photoconductor 1 is represented by v _e, and the surface potential of the exposed area (latent image area) is represented by _VL . The current image bias voltage applied to the developing low La 8 as a V _B, the surface potential V _D of the developing roller 8 and equal to the development by § scan voltage v _B. The electrostatic latent image on the photoconductor 1 is reversely developed by toner particles charged to the same polarity as the electrostatic latent image. Vp, V and v _D have the same polarity. Reversal in the development, arbitrary each surface potential favored and a set child so as to satisfy the relation _{_{IV c I> IV D I>}} IV L I.

In order to perform reversal development, as shown in FIG. 3 (A), the surface of the photoreceptor 1 is uniformly and uniformly charged to, for example, about V = + 800 V, as shown in FIG. Note that V _e is usually set to about 50,000 to 900 V in absolute value. Next, as shown in FIG. 3 (B), the latent image forming means 4 irradiates light with a predetermined pattern to partially release the charge on the surface of the photoreceptor 1 to form a predetermined pattern. An electrostatic latent image is formed. That is, the charge of the exposed portion is eliminated by the photoconductive property of the positively chargeable organic photoreceptor layer. The absolute value of the potential of the area where the electrostatic latent image is formed is about 0 to 100 V, and usually a voltage close to zero V. Next, the electrostatic latent image on the surface of the photoreceptor 1 is developed by the developing means i. As shown in Fig. 3 (C), the current On the surface of the developing port roller 8 of the image means A, the layer thickness is regulated by the operation of the developing port roller blade 9, and a single layer of substantially spherical toner particles 10a is formed. Have been. As the surface potential V _D of the developing opening one la 8 is for example + 4 0 0 V, between the developing roller 8 and the photosensitive member 1 (for example example, + 4 0 0 V) Baiasu voltage is applied. For this reason, as shown in FIG. 3 (C), the charged toner particles 10a adhering to the outer peripheral surface of the developing roller 8 are electrostatically charged to the light irradiation part (exposure part). The latent image moves to the surface of photoreceptor 1, and the surface of photoreceptor 1 has a toner image on the surface of photoreceptor 1 in the electrostatic latent image pattern, as shown in FIG. 3 (D). It is formed.

On the other hand, as shown in Fig. 3 (C), as shown in Fig. 3 (C), the residual toner particles 1 Ob adhering to the area other than the electrostatic latent image on the photoreceptor 1 It moves to the developing roller 8 side by the electric field based on the surface potential. As a result, the surface of the photoconductor 1 can be cleaned at the same time as the development. Therefore, in the reversal development method, the cleaning means 202 shown in FIG. 2 is not required.

In this case as a condition for performing the simultaneous development click rie two ring, the front surface charge potential of the photosensitive member 1 and V _c, the surface potential of the developing opening one la 8 was V _D, IV _c - V _D I arbitrarily preferred that (the absolute value) is that 5 0 V or more. When the potential at the tip of the blade 9 for the developing roller shown in FIG. 1 is V and the surface potential of the supply roller 12 is v _s , I v _D I ≤ I v _BL i ≤ I v _s I Is preferred. When the charge polarity of the toner particles 10 and the polarity of the surface potential of the photoreceptor 1 are positive, the relationship of V _c — V _D ≥ 50 V and V _D ^ V _B , ≤ v _s I prefer that there be. This relationship is the same in the case of performing simultaneous development cleaning in regular development.

In the present invention, first, the material of the surface of the electrophotographic photoreceptor is a phthalocyanine compound as a charge generating agent, and a diquinoquino compound as an electron transporting agent. Positively chargeable organic photoreceptor containing a nitrogen-containing compound and a nitrogen-containing polyaromatic compound as a hole transport agent. Second, for toner particles, the sphericity obtained by dividing the area (Sc) of a circle whose diameter is the absolute maximum length of the particle by the effective projected area (Sr) of the particle is 1.0 to 1.0. Use colored polymer particles which fall within the range of 1.3 and are produced by a suspension polymerization method. Third, the developing means also serves as a cleaning means for collecting toner particles remaining on the electrophotographic photosensitive member during transfer.

In the image forming apparatus of the present invention, since the electrophotographic photosensitive member whose surface material is the above-described positively chargeable organic photosensitive member is used, the corona discharge device (h) is used as the charging means. Ozon generation can be effectively suppressed even with the use of a major wire device. In other words, the conventional negatively charged organic photoreceptor has a problem that a large amount of ozone is generated due to the use of the negative corona discharge. The generation of ozone not only pollutes the environment, but also degrades the photoreceptor and requires an ozone decomposer and a discharger. Also, in the method using a charging port instead of a corona discharge device, the charging roller comes into contact with the surface of the photoreceptor, which causes fogging due to toner particles adhering to the charging roller and the compounding agent in the charging roller. The problem of photoconductor contamination is likely to occur, and furthermore, it is difficult to select the material of the charging roller and to control the process in order to uniformly apply the same amount of charge, which increases the cost. However, in the image forming apparatus of the present invention, an inexpensive corona discharge apparatus having little effect on the photoconductor can be used as the charging means.

The above-mentioned positively chargeable organic photoreceptor is made by dispersing a photosensitive organic compound in a resin such as polycarbonate. Also easily scratched. However, as described above, a non-contact corona discharge device is used as the charging means. When used, there is no problem of photoconductor damage or contamination. Also, by using a positively charged corona discharge device (charger wire) in combination with the positively chargeable organic photoreceptor, the amount of ozone generated is reduced.

When the organic photoreceptor is cleaned by a cleaning means, the cleaning blade comes into contact with the photoreceptor, so that the organic photoreceptor is easily damaged and the life is shortened. In addition, the residual toner on the photoreceptor is easily crushed by contact with the cleaning blade. When crushed, the remaining toner such as a charge controlling agent, a release agent, and a coloring agent present on the fracture surface is crushed. Filming due to adhesion is likely to occur. The toner particles are subjected to a long-term stress between the cleaning blade and the photoreceptor, and as a result, the toner particles are liable to become fine particles and poor charging is likely to occur. Since rubber blades are generally used as cleaning blades, poor cleaning is likely to occur due to the amount of rubber that has passed over time.

On the other hand, in the image forming apparatus and the image forming method of the present invention, the cleaning means is not required, so that the durability of the photoreceptor is increased, the size of the entire apparatus is reduced, and the durability of the toner particles is reduced. It can also contribute to improvement. In the simultaneous development cleaning method, if the amount of residual toner on the photoreceptor after transfer is large, the cleaning is not sufficiently performed by the developing means, and positive ghosts are likely to occur. By using the particles in combination with the positively chargeable organic photoreceptor, the transfer efficiency is improved, so that the residual toner after transfer can be greatly reduced.

In the present invention, it is preferable to use a transfer roller as the transfer means 6, as shown in FIG. The reason is that the transfer means 6 charges from the back of the transfer material negatively with a polarity opposite to the polarity of the electrostatic latent image on the photoreceptor, Non-contact changer It is better to transfer the toner image on the photoreceptor 1 by contacting the transfer roller via the transfer material than to transfer with a one-line device. Ozone odor is also generated in terms of transfer efficiency. It is also desirable to reduce Since the transfer roller is indirectly in contact with the photoconductor via the transfer material, it does not damage or contaminate the photoconductor. The transfer roller is usually made by coating a conductive shaft with a rubber elastic body, but the rubber elastic body has a conductive force such as a conductive black to adjust the electric resistance value. Particles can be appropriately blended.

Example

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. However, the present invention is not limited to only these Examples.

[Example 1]

An image forming apparatus according to the present embodiment will be described.

A 4 mm thick rubber elastic body was formed on the outer peripheral surface of the stainless steel shaft 1 Omm0, and the surface was polished to produce a developing roller 8. As shown in Fig. 1, this image roller was placed in contact with a photoreceptor (photoreceptor drum) 1 so that the contact width was 2 mm. Photoconductor 1 had a positively chargeable organic photoconductor layer formed on the surface thereof, and had an outer diameter of 3 O mm. And a charging device 3, using a corona discharge device UNA by becomes uniform on the surface potential V _e is + 8 0 about 0 V of the photoreceptor 1. As the electrostatic latent image forming device 4, a combination of a laser irradiation device and an optical system device was used. As the developer supply port 12, a urethane rubber sponge roller having an outer diameter of 13 mm was used. The supply roller 12 was brought into contact with the developing roller 8 so that the contact width became 2 mm. Developer layer thickness As the regulating blade 9, a flat blade made of urethane rubber elastic body was used. The electrical resistance of this blade was 6 × 10 ⁴ Ω. As shown in FIG. 1, the blade 9 was attached in contact with the outer peripheral surface of the developing roller 8 such that the linear pressure on the developing roller 8 was 0.7 to 2 gZmm.

Positively chargeable organic photoreceptor>

Photoreceptor 1, whose surface was a positively chargeable organic photoreceptor, was prepared using the following materials.

(1) Charge generator: X-type metal free phthalocyanine '· · 3 parts by weight (2) Hole transport agent: 3, 3' — dimethyl-Ν, ,, Ν ', Ν' tetra Kiss (4-methyl phenyl) 1, 1 '-bi-vinyl 4, 4'-diamin 50 parts by weight

③Electron transport agent (Α): 3,5 —dimethyl 3 ', 5' —di-tert-butyl-1,4,4'-diphenoquinone 45 parts by weight ④Electron transport agent (Β) : 3, 3 ', 5, 5'-Tetra-taper-leaving Chill 4, 4 '-Diphenylquinone 5 parts by weight Polycarbonate as binder resin 100 parts by weight Using a sufficient amount of dichloromethane to disperse or dissolve each component as a solvent, and a solvent, add each of the components and mix and disperse them with a ball mill. A liquid was prepared. This coating solution is applied to the outer peripheral surface of the aluminum tube, and dried with hot air at 100 for 60 minutes to form a photoreceptor layer with a film thickness of 15 to 20 / m. Thus, a single-layer type electrophotographic photosensitive member was obtained. <Toner particles>

As the toner particles 10 contained in the developing device 5, the colored polymer particles obtained by the following production method were used.

'' Polyethylene 8 5 parts by weight • n — butyl acrylate · 15 parts by weight

• 7 parts by weight of carbon black

(Legal 990R, manufactured by Cabbot)

• Charge control agent

① Nigrosine dye 0.01 parts by weight

(N-05, manufactured by Orient Chemical Co., Ltd.)

② Grade 4 ammonium salt 0.0 2 parts by weight

(P-53, manufactured by Orient Chemical Co., Ltd.)

'' 0.3 parts by weight of divinylbenzene · t-butyl propyl 2.-ethyl hexanoate · 4 parts by weight

• 2 parts by weight of polypropylene

(Viscole 550 P, manufactured by Sanyo Chemical Industries)

However, the nig mouth cin-based dye and the quaternary ammonium salt were used in advance by pulverizing and classifying with a jet mill to reduce the volume average particle diameter to 3 zm or less.

The above components were stirred and mixed by a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), which is a mixer having a high shearing force, to prepare a uniformly dispersed polymerizable monomer composition.

250 parts by weight of ion-exchanged water dissolved in an aqueous solution of 10.2 parts by weight of magnesium chloride (water-soluble polyvalent metal salt), and 50 parts by weight of ion-exchanged water were added to sodium hydroxide. (Alkali hydroxide) 6. 2 parts by weight of an aqueous solution dissolved therein was gradually added with stirring to obtain a magnesium hydroxide colloid (a colloid of a poorly water-soluble metal hydroxide). . The polymerizable monomer composition is added to the magnesium hydroxide dispersion, and the mixture is subjected to high shear stirring using a TK homomixer to granulate droplets of the polymerizable monomer composition. did. The aqueous dispersion of the granulated polymerizable monomer composition is supplied to a stirring blade. The polymerization was carried out under stirring at 90 ° C. for 8 hours in the reactor. The reaction product was filtered from the polymerization reaction mixture, sufficiently washed with acid and water, and dried to obtain colored polymer particles (toner particles). When the particle size of the toner particles was measured by Coulter Counter (manufactured by Coulter Corporation), the volume average particle size (dV) was 8 m. The toner particles have a ratio (dv Z dn) between the volume average particle diameter (dV) and the number average particle diameter (dn) of 1.20, and the diameter of the circle is the absolute maximum length of the particle. The area (Sc) divided by the real projected area (Sr) of the particle (Sc / Sr) was a substantially spherical shape with a force of 1.1. Moreover, the preparative toner particles, BET method specific surface area (A) = 0. 6 8! 1 2 Bruno, true specific gravity (0) = 1.1 0, product AX dn XD = 7. 4, charge amount (Q) It was 2 3 2 ^ c Z g, 0 ratio = 47.

To 100 parts by weight of the toner particles obtained as described above, 0.5 parts by weight of hydrophobically treated colloidal silica (HVK2150, manufactured by Hexstar Co., Ltd.) was added. (4) Mixing was performed using a luminescence mixer to obtain a non-magnetic one-component developer.

In this embodiment, in order to perform a simultaneous development cleanings by reverse developing method, between the developing opening one la 8 and the photosensitive member _{_{1 (V c - V D =}} ) + 4 0 0 V bus it § scan of A voltage was applied. The surface potential of the exposed portion of the photoreceptor was set to (Vj ^ =) + 100 V. A bias voltage of (V _BL =) + 400 V was applied to the thickness regulating blade 9. A bias voltage of (V _s =) + 800 V was applied to the supply port 12. In this embodiment, since the cleaning is performed simultaneously with the development, the cleaning means 202 as shown in FIG. 2 is unnecessary. In the image forming apparatus according to the present embodiment, the photoconductor 1 is rotated in the direction of the arrow at a peripheral speed of 40 mm second, and the developing roller 8 is rotated at a peripheral speed of 100 mm second. The supply roller 12 was rotated in the direction of the arrow at a peripheral speed of 5 Omm / sec, and the toner image on the photoreceptor 1 was transferred onto the transfer paper 7 to evaluate the image.

The obtained image was high in image density, clear and free of background stains, dust, and unevenness. Even after continuous printing of 20,000 sheets, no toner filming occurred and stable image quality was obtained. . Also, there was no generation of ozone and no odor was noticed.

[Example 2]

In Example 1, as the hole transporting agent for the positively chargeable organic photoreceptor, 3,3′-dimethyl-N, N, N ′, N′-tetrakis (4-methylinophenyl) 1, 1 'one bifurcation 4, 4'-instead of diamin, N, N, N ', N'-tetrakis (3-methinorefenyl) phenylene 1, 3 — Except for using diamine, the same procedure as in Example 1 was performed and evaluated. The obtained image is high in image density, clear and free of background stains, dust, and unevenness. Even after continuous printing of 20,000 sheets, there is no occurrence of fining and stable image quality. Obtained. In addition, there was no generation of ozone and no odor was noticed.

[Comparative Example 1]

Styrene Zn—butyl creatine / divinylbenzene

(Weight ratio 8.5 15 0.3) copolymer 100 parts by weight

'' Carbon black 7 parts by weight

(Legal 990R, manufactured by Cabot Corporation)

• Charge control agent

(1) 2.0 parts by weight of nigrosine dye (N-O5, manufactured by Orient Chemical Co., Ltd.)

② Class 4 ammonium salt 0.5 parts by weight (P-53, manufactured by Orient Chemical Co., Ltd.)

'' 2 parts by weight of polypropylene

(Viscole 550P, manufactured by Sanyo Chemical Co., Ltd.)

The above components were blended, kneaded, crushed, and classified to obtain black toner particles having a volume average particle size of 8 / zm. The sphericity of the obtained toner particles was 1.4. To 100 parts by weight of the toner particles obtained in this manner, 0.5 parts by weight of a hydrophobized colloidal silica (trade name: HVK2150, manufactured by Hexstar) was added. A non-magnetic one-component developer was obtained by mixing using a Hensil mixer.

When printing evaluation was performed in the same manner as in Example 1 using the current image agent obtained above, the image density was initially low, the fogging was high, and the image quality was insufficient. Was.

When the printing evaluation was performed in the same manner as in Example 1 except that this developer was used and an image forming apparatus equipped with a cleaning device was used, the obtained image had an image density of It was clear and had a clear background without dirt, dust, and glare. There was no generation of ozone and no odor was noticed. However, when continuous printing was performed on 20,000 sheets, white streaks were seen on about 3,000 sheets, and fog occurred on about 5,000 sheets. When the developing device was disassembled, toner filming occurred on the developing blade, and the image quality was not stable.

[Comparative Example 2]

In Example 1, a negatively chargeable organic photoreceptor was used instead of the positively chargeable organic photoreceptor. The negatively chargeable organic photoreceptor is a laminated photoreceptor produced by providing an intermediate layer made of a polyamide resin, and then sequentially applying a charge generation layer and a charge transfer layer. The charge generation layer is prepared by dissolving titanyl phthalocyanine and polyvinyl butyral resin in a weight ratio of 1/1. A coating liquid dispersed in a solvent is applied, and the charge transfer layer is formed by dissolving a styrene-triphenylamine-based charge transfer material and polycarbonate in a solvent at a weight ratio of 3Z4. By performing the coating, it was manufactured so that the dry film thickness became 20 / m, and the outer diameter was 30 mm.

As the charging device of the image evaluation device, a corona discharge device was used so that the surface potential of the photoreceptor became uniform at (V _e =)-800 V. A bias voltage of (V (; — V _D =) — 400 V was applied between the developing roller and the photosensitive element, and (V _BL =) — 400 V was applied to the layer thickness regulating blade 9. A bias voltage of (V _S =) — 800 V was applied to the supply port 12.

As the toner particles, in the method for producing the toner particles of Example 1, (1) Nig mouth cin-based dye (N-05, manufactured by Orient Chemical Co.) 0.01 part by weight and (2) Class 4 Ammonium salt (P-53, manufactured by Orient Chemical Co., Ltd.) Instead of 0.02 parts by weight, 2.0 parts by weight of a negatively charged chrome dye (Bontron S-34) is used. A calcium phosphate dispersion in which 3 parts by weight of calcium phosphate are finely dispersed in 250 parts by weight of distilled water in place of the magnesium hydroxide dispersion used and the dispersion used. A toner particle obtained by suspension polymerization in the same manner as above was used. The characteristics of the toner particles were dv = 8 m, dV / dn = 1.42, Sc / Sr = 1.1, Axdnx D = 7.6, and <38 = —45. . In the same manner as in Example 1, a non-magnetic one-component developing agent was obtained by adding a colloidal Dull force that had been hydrophobized to the toner particles.

The resulting image has a high image density, is clear with no background smear, dust, or glaring, and is free of filming even in continuous printing of 20,000 sheets, resulting in stable image quality. was gotten. However, when ozone was generated and continuous printing was performed, the odor was so bad that it could not be removed. Dagger Comparative Example 3]

In the photoreceptor of Example 1, N, N'-page (3,5—dimethinolepanol) perylene-1,3,4,9,10—Tetracal was used as the charge generating agent. A single-layer photoreceptor was obtained in the same manner except that boxyimide was used. Printing evaluation was performed in the same manner as in Example 1 except that the image forming apparatus incorporating the single-layer type photoreceptor was used. As a result, the printing quality was poor, and filming was observed after continuous printing of 50,000 sheets.

Table 1 shows the results of the above Examples and Comparative Examples. table 1

(footnote)

(1) Ozon odor 〇: If you do not feel the odor of ozone during printing,

X: When the odor of ozone is severe during printing.

(2) Print quality

〇: When the image density is high and the image is clear with no background stains,

X: When one or more of image density, background stain, dust, glaring, and fogging is poor,

〇 → X: Initial printing quality is good, but continuous printing deteriorates printing quality.

(3) Finalizing (20K)

〇: After continuous printing of 20,000 sheets, if there is no toner filming on the photoconductor,

X: Toner filming on the photoreceptor after continuous printing of 20,000 sheets.

(4) Finalizing (50K)

〇: After continuous printing of 50,000 sheets, if there is no toner filming on the photoconductor,

X: Toner filming on the photoreceptor after continuous printing of 50,000 sheets. Industrial applicability

According to the present invention, there is provided a cleaner-less type image forming apparatus which collects residual toner on a photoconductor at the same time as development by a developing means, and has a high image density, a stable image quality, and a high image quality. A new image forming apparatus in which generation of noise is suppressed is provided. Further, according to the present invention, there is provided a cleanerless image forming method, which has a high image intensity and a stable image forming method. Provided is an image forming method which shows image quality and suppresses generation of ozone. Further, according to the present invention, toner particles suitable for such a cleanerless image forming method are provided.

Claims

The scope of the claims

1. A toner image is formed on the electrophotographic photoreceptor by developing means containing toner particles, and the toner image is transferred to a transfer material to output an image, which adheres to the electrophotographic photoreceptor. In the image forming apparatus S in which the developing means also serves as a cleaning means for collecting the remaining toner particles after the transfer,

(1) The material of the surface of the electrophotographic photoreceptor contains a phthalocyanine compound as a charge generating agent, a diphenoquinone compound as an electron transporting agent, and a hole transporting agent. A positively chargeable organic photoreceptor containing a nitrogen polyaromatic compound, and

(2) The toner particles have a sphericity of 1.0 to 1.3 obtained by dividing the area (S c) of a circle whose diameter is the absolute maximum length of the particles by the real projected area (S r) of the particles. Colored polymer particles within the range and produced by the suspension polymerization method

An image forming apparatus characterized by the above.

2. The image forming apparatus according to claim 1, wherein the phthalocyanine-based compound as the charge generator is X-type metal free phthalocyanine or oxotitanyl phthalocyanine.

3. The ditransinoquinone compound as an electron transporting agent is 3, 5-dimethyl-3 ', 5'-di-tert-butyl-4, 4 '-di-quinoquinone, 3, 3' Chill 5, 5 '-Digital butyl-1, 4'-Diphenoquinone and 3, 5 '-Dimethyl 1-3', 5-Digital butyl 1, 4 '- Selected from the group consisting of diphenoquinone At least one dibenzoquinone-based compound (A) 50-97% by weight, 3,3 ', 5,5''-Dipinoquinone, 3, 3', 5, 5 '-Tetraethynolee 4, 4'-diphenoquinone and 3, 3 ', 5, 5'-tetramethyl Claim 1 wherein at least one kind of diphenoquinone-based compound (B) selected from the group consisting of 1,4,4'-dibenzoquinones is 3 to 50% by weight. Or the image forming apparatus according to 2.

4. The method according to any one of claims 1 to 3, wherein the nitrogen-containing polyaromatic compound of the hole transport agent is a biphenyldiamine-based compound or a phenylenediamine-based compound. Image forming device.

5. An electrophotographic photoreceptor is provided with a single layer of a positively chargeable organic photoreceptor made of a resin composition containing a charge generating agent, an electron transporting agent, a hole transporting agent, and a binder resin on a conductive substrate. The image forming apparatus according to any one of claims 1 to 4, wherein the image forming apparatus is formed.

6. The toner particles contain at least a binder resin and a colorant, and (1) have a volume average particle diameter (dv) of l to 50;

(2) The ratio (dVZdn) of the volume average particle diameter (dV) to the number average particle diameter (dn) is 1.0 to 1.4,

(3) BET specific surface area (A) (mVg), number average particle size (dn)

(^ m), and the product (A x d n x D) of the true specific gravity (D) are 3 to 8, and

(4) The absolute value of the ratio (QZA) between the charge amount (Q) (cZg) and the specific surface area (A) is 10 to 100

The colored polymer particles falling within the range of (1) to (5). Item 10. The image forming apparatus according to item 1.

7. The image forming apparatus according to any one of claims 1 to 6, wherein the toner particles are positively chargeable.

8. An aqueous dispersion medium in which toner particles contain a polymerizable monomer composition containing at least a polymerizable monomer and a colorant, and a sparingly water-soluble metal hydroxide as a dispersion stabilizer. The image forming apparatus according to claim 1, wherein the polymer particles are colored polymer particles obtained by suspension polymerization using a polymerization initiator.

9. The image forming apparatus according to claim 8, wherein the poorly water-soluble metal hydroxide is obtained by reacting a water-soluble polyvalent metal salt with an aluminum hydroxide in an aqueous phase.

10. The image forming method according to claim 8, wherein the polymerizable monomer is a monomer mixture containing aromatic vinyl, acrylic acid or a derivative of methacrylic acid, and a crosslinking agent. apparatus.

1 1. Toner particles are used as charge control agents such as nigrosine dye, quaternary ammonium salt, monoazo dye, metal-containing dye, zinc hexadecyl succinate, and alkyl ester of naphthoic acid. Or alkyl amide, nitrofamic acid, N, N'-tetramethyldiamine benzophenone, N, N'-tetramethyltylbenzidine, triazine, and triazine. The image forming apparatus according to any one of claims 1 to 10, comprising at least one compound selected from the group consisting of lithic acid metal complexes. apparatus.

12. The image forming apparatus according to any one of claims 1 to 11, wherein the toner particles have colloidal silica as a fluidizing agent adhered to the surface.

1 3. The developing device is a developing device including a developing roller, a developing roller blade, toner particle storage means, and a supply roller, and the developing roller is arranged in contact with the photoconductor. The surface image forming apparatus according to any one of claims 1 to 12, wherein the surface image forming apparatus comprises:

14. The image forming apparatus according to any one of claims 1 to 13, wherein the image forming apparatus includes charging means for uniformly charging the surface of the photoreceptor, and the charging means is a corona discharge device. apparatus.

15. The image forming apparatus according to any one of claims 1 to 14, wherein the image forming apparatus includes a transfer unit for transferring the toner image on the photoconductor onto the transfer material, and the transfer unit is a transfer roller. Item 2. The image forming apparatus according to item 1.

16. A developing roller carrying a toner particle layer is arranged facing the electrophotographic photoreceptor, and a latent image area on the photoreceptor is developed by toner particles on the developing roller. In an image forming method, cleaning is performed by sucking and removing residual toner particles adhering to a non-latent image area on a body toward a developing roller.

(1) The surface material of the electrophotographic photoreceptor is a phthalocyanine-based compound as a charge generator, and a difunoquinone-based compound as an electron transport agent. A positively chargeable organic photoreceptor containing a compound and a nitrogen-containing polyaromatic compound as a hole transporting agent; and

(2) As toner particles, the sphericity obtained by dividing the area (Sc) of a circle whose diameter is the absolute maximum length of the particle by the real projected area (Sr) of the particle is 1.0 to 1 Use colored polymer particles that fall within the range of 3 and that are produced by a suspension polymerization method.

An image forming method characterized by the above.

17. The image forming method according to claim 16, wherein the phthalocyanine compound as a charge generating agent is X-type metal free phthalocyanine or oxo titanyl phthalocyanine.

1 8. The ditransinoquinone compound as an electron transporting agent is 3, 5-dimethylol 3 ', 5'-digital phenyl 4, 4, 4 'diphenoquinone, 3, 3 '— Dimethyl quinone 5 and 5' — Digital jar 4 and 4 '— Diphenoquinone and 3,5' — Dimethyl 1 3 'and 5 — Dialkyl butyl 1 4 , 4'-dibenzoquinone, at least one dipinoquinone-based compound (A) selected from the group consisting of 50-97% by weight, 3,3 ', 5 , 5'-Tetra-tert-butyl-4,4'-Diphenoquinone, 3,3 ', 5,5'-Tetra-ethyl-4,4'-Diphenoquinone and 3 , 3 ', 5, 5' — Tetramethyl-1, 4,

Claims wherein at least one kind of diphenoquinone-based compound (B) selected from the group consisting of 4'-diquinoquinones is 3 to 50% by weight. 16. The image forming method according to 16 or 17.

1 9. The nitrogen-containing polyaromatic compound of the hole transport agent is 19. The image forming method according to claim 16, wherein the image forming method is a mine-based compound or a phenylenediamine-based compound.

20. A single layer of a positively chargeable organic photoreceptor comprising a resin composition containing a charge generating agent, an electron transporter, a hole transporter, and a binder resin on a conductive substrate. The image forming method according to any one of claims 16 to 19, wherein the image is formed.

2 1. The toner particles contain at least a binder resin and a colorant, and (1) a volume average particle diameter (dv) of 50 to 50 / m,

(2) The ratio of the volume average particle diameter (dv) to the number average particle diameter (dn) (dv / dn) force 1.0 ~: L.4,

(3) BET specific surface area (A) (m ² / g), number average particle size (dn)

(4) The absolute value of the ratio (QZA) between the charge amount (Q) (^ cZg) and the specific surface area (A) is 10 to 100

The image forming method according to any one of claims 16 to 20, wherein the colored polymer particles are in the range of:

2 2. An aqueous dispersion medium in which the toner particles contain a polymerizable monomer composition containing at least a polymerizable monomer and a colorant, and a sparingly water-soluble metal hydroxide as a dispersion stabilizer. The image forming method according to any one of claims 16 to 21, wherein the polymer particles are colored polymer particles obtained by suspension polymerization using a polymerization initiator.

2 3. The poorly water-soluble metal hydroxide is composed of a water-soluble polyvalent metal salt and The image forming method according to claim 22, wherein the method is obtained by reacting a resin in an aqueous phase.

24. The method according to claim 22, wherein the polymerizable monomer is a monomer mixture containing aromatic vinyl, acrylic acid or a derivative of methacrylic acid, and a crosslinking agent. Image forming method.

25. Toner particles are used as a charge control agent for Nig-Cin dyes, quaternary ammonium salts, monoazo dyes, metal-containing dyes, zinc hexadecyl succinate, and anoalkyl esters of naphthoic acid. Or alkyl amide, nitrofamic acid, N, N'-tetramethyltilminebenzofunone, N, N'-tetramethyltilbenzycin, triazine, 25. The image forming method according to any one of claims 16 to 24, wherein the method comprises at least one compound selected from the group consisting of: and a salicylic acid metal complex.

26. The image forming method according to any one of claims 16 to 25, wherein the toner particles have colloidal silica as a fluidizing agent adhered to the surface.

27. The developing roller carrying the toner particle layer is a developing roller carrying a toner particle layer charged to the same polarity as the electrostatic latent image forming the latent image area on the photoreceptor. Item 16. The image forming method according to any one of Items 16 to 26.

28. The toner according to any one of claims 16 to 27, wherein the toner particles are positively charged. 2. The image forming method according to claim 1.

2 9. When the surface potential of the non-latent image area on the photoreceptor is V _e , the surface potential of the latent image area on the photoreceptor is V, and the surface potential of the developing roller is v _D , the equation I v _e I > IV _D I> IV, claim 1 6 to the image forming method of placing serial to any one of 2 8 for to the image forming configure each surface potential so as to satisfy the relationship represented by I.

_{. 3 0 IV -. V D} I ≥ 5 0 image forming method according to claim 2 9, wherein the set each surface conductive position to satisfy the bolt relationship form an image.

3 1. Applying a Baiasu voltage V _B between the photosensitive member and the developing opening one la, or One,請Motomeko 2 9 or 3 to match the Baiasu voltage v _B and the surface potential v _D of the developing opening one la 0. The image forming method according to 0.

32. The image forming method according to any one of claims 16 to 31, wherein reversal development is performed.

3 3. The surface material of the electrophotographic photoreceptor is a phthalocyanine compound as a charge generator, a difunoquinone compound as an electron transport agent, and a hole transporter. A positively chargeable organic photoconductor containing a nitrogen-containing polyaromatic compound is used as a developer, and a developing roller carrying a toner particle layer is arranged opposite to the photoconductor, and is disposed on the photoconductor. The latent image area is developed with toner particles on the developing roller, and at the same time, residual toner particles adhering to the non-latent image area on the photoreceptor are removed by suction to the developing roller side for cleaning. Used in the image forming method including the method of performing The toner particles have a sphericity of 1.0 to 1.3 obtained by dividing the area (Sc) of a circle whose diameter is the absolute maximum length of the particle by the actual projected area (Sr) of the particle. And toner particles which are colored polymer particles produced by a suspension polymerization method.