JP5272521B2 - Image carrier protecting agent, protective layer forming apparatus, image forming method, image forming apparatus, process cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image carrier protecting agent capable of obtaining a sufficient protecting effect on the surface of an image carrier, preventing wear and deterioration in a cleaning member, preventing toner from passing, preventing filming on an image carrier, and preventing contamination on a charging member, and to provide a protective layer forming device capable of forming a satisfactory image carrier protective layer by using the above protecting agent. <P>SOLUTION: The image carrier protecting agent is used for an image forming method or an image forming apparatus including at least an image carrier 1 and a step or a device 2 for applying or depositing an image carrier protecting agent 21 on the surface of the image carrier, wherein the image carrier protecting agent 21 contains a hydrophobic organic compound (A), an inorganic lubricant (B), inorganic fine particles (C) and a surface-treated inorganic lubricant (D). The protective layer forming device 2 is equipped with at least the image carrier protecting agent 21 and a protecting agent supply member 22, and supplies the image carrier protecting agent 21 to the surface of the image carrier 1 via the protecting agent supply member 22. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an image carrier protecting agent that is applied or attached to protect the surface of the image carrier in an electrophotographic image forming method or image forming apparatus, and to apply or attach a protective agent to the surface of the image carrier. The present invention relates to a protective layer forming apparatus for forming a protective layer, an image forming method having the image carrier protecting agent or the protective layer forming apparatus, an image forming apparatus, and a process cartridge.

  Conventionally, in electrophotographic image formation, an electrostatic charge latent image is formed on an image carrier made of a photoconductive substance and the like, and charged toner particles are attached to the electrostatic latent image to make it visible. An image is formed. The visible image formed by the toner is finally transferred to a transfer medium such as paper, and then fixed to the transfer medium by heat, pressure, solvent gas, or the like, and becomes an output image.

  These image forming methods include a so-called two-component development method that uses friction charging by stirring and mixing toner particles and carrier particles by a method of charging toner particles for visualization, and without using carrier particles. In other words, the toner particles are roughly classified into so-called one-component developing methods for applying charge to toner particles. The one-component development method is classified into a magnetic one-component development method and a non-magnetic one-component development method depending on whether or not magnetic force is used to hold toner particles on the developing roller.

Up to now, in copiers that require high speed and image reproducibility, and multi-function machines based on this, two components are required due to the requirements of toner particle charging stability, rise-up performance, long-term image quality stability, etc. Many developing methods have been adopted, and one-component developing methods have been often used for small printers, facsimiles, and the like, which require large space savings and low costs.
In particular, in recent years, colorization of output images has progressed, and the demand for higher image quality and stabilization of image quality has become stronger than ever.
In order to improve the image quality, the average particle diameter of the toner is reduced, and the shape of the particles is not rounded and becomes more round.

  In these electrophotographic image forming apparatuses, a drum-shaped or belt-shaped image carrier (generally a photosensitive member) is uniformly charged while rotating regardless of the development method, and laser light, etc. To form a latent image pattern on the image bearing member, which is visualized by a developing device, and further transferred onto a transfer medium.

  Further, the toner component that has not been transferred remains on the image carrier after the toner image is transferred to the transfer medium. When these residues are conveyed to the charging process as they are, it is often the case that the uniform charging of the image carrier is hindered. The components and the like are removed in a cleaning process to make the surface of the image carrier sufficiently clean, and then charging is performed.

As described above, the surface of the image carrier is subjected to various physical stresses and electrical stresses in various processes such as charging, development, transfer, and cleaning, and the surface state changes as the usage time elapses.
Of these stresses, it is known that the stress due to friction in the cleaning process causes the image carrier to wear and causes scratches. In order to solve this problem, many proposals have been made so far regarding various lubricants and methods for supplying lubricant components and forming films in order to reduce the frictional force between the image carrier and the cleaning member.

For example, in the prior art described in Patent Document 1, in order to extend the life of the photoconductor and the cleaning blade, a solid lubricant mainly composed of zinc stearate is supplied to the surface of the photoconductor to form a lubricant film on the surface of the photoconductor. It has been proposed.
In the prior art described in Patent Document 2, the higher alcohol is indefinite at the tip of the blade nip by using a lubricant supply device that supplies a lubricant mainly composed of a higher alcohol having 20 to 70 carbon atoms. It retains as particles and has appropriate wettability to the surface of the image bearing member, so that the durability of the lubricating performance is expressed.

In the prior art described in Patent Document 3, by using a powder of a specific alkylene bisalkyl acid amide compound as a lubricating component, fine powder particles exist at the interface where the cleaning blade and the image carrier are pressed against each other. For this reason, a smooth lubricating action can be maintained over a long period of time.
Further, in the prior art described in Patent Document 4, an image carrier and a cleaning member are supplied by supplying various lubricants obtained by adding an inorganic lubricant to a solid lubricant mainly composed of zinc stearate on the surface of the photoreceptor. The frictional force between them can be reduced.

  In the prior art described in Patent Document 5, the surface of the image carrier by the charging process is supplied by supplying various lubricants added with boron nitride to a solid lubricant mainly composed of zinc stearate on the surface of the photoreceptor. Even when subjected to electrical stress, it is difficult for the lubricity to decrease, and a lubricant film can be formed over the entire surface of the image carrier to maintain high lubricity.

  On the other hand, in recent years, a toner using a polymerization method has been put on the market in order to improve image quality and reduce manufacturing energy. These polymerized toners have excellent characteristics such as fewer angular portions and smaller average particle diameters than toners produced by a pulverization method. However, these features are affected by the shape and particle size of a method for cleaning the surface of the image carrier by pressing the edge of a cleaning member represented by rubber blade cleaning against the surface of the image carrier. As a result, it is difficult for the edge portion to be dammed, and the residual toner component tends to be poorly cleaned.

There have been some proposals for the prior art corresponding to such toner cleaning failure.
For example, in the prior art described in Patent Document 6, the hydrophobicity and amphiphilic organic compounds are used to dramatically improve the cleaning performance of the toner. It is possible to clean. Further, the cleaning property has been improved, so that contamination of the charging member is reduced, and the life of the charging member can be extended. Further, since the toner does not slip through, the blade wear is small, and the life of the cleaning blade can be extended.

Japanese Patent Publication No.51-22380 JP 2005-274737 A JP 2002-97483 A JP 2005-171107 A JP 2006-350240 A JP 2007-286594 A

  However, as described above, the stress on the image carrier is not only received from the cleaning process, but the electrical stress particularly in the charging process greatly changes the state of the surface of the image carrier. Further, this electrical stress is conspicuous in the contact charging method and the proximity charging method that involve a discharge phenomenon near the surface of the image carrier. In these charging methods, many active species and reaction products are generated on the surface of the image carrier, and many active species and reaction products generated in the atmosphere in the discharge region are adsorbed on the surface of the image carrier. .

The lubricant using zinc stearate as in the prior art described in Patent Document 1 described above covers the surface of the image carrier relatively evenly and provides good lubricity and protection. Therefore, in order to prevent photoconductor wear, which is a problem in the image forming process in which an AC voltage is applied when charging the image carrier, it can be easily solved by using zinc stearate.
However, zinc stearate has a big problem in terms of cleaning properties. In a normal image forming process, a blade cleaning system is adopted as a means for removing the residual toner after transfer from the photoreceptor. However, zinc stearate has a property that the toner easily slips through the blade. If the toner slips through the cleaning blade, the toner directly appears on the image, or the contamination of the charging member is further accelerated. The toner slipping becomes more noticeable as the toner becomes spherical with a small particle diameter. In addition, since a material using zinc stearate often slips out of toner or the like, the cleaning blade is worn and the image forming apparatus has a short life.
Further, the toner slipping in the cleaning step causes a large amount of zinc stearate to slip through at the same time as the toner, which causes a problem of contaminating the charging member. In particular, in the case where the charging roller is charged by being in contact with or in close proximity to the photosensitive member, the contamination of the charging member increases. When the charging member is contaminated, an abnormal image such as density unevenness due to charging unevenness occurs.

  In addition, the conventional higher alcohol lubricant disclosed in Patent Document 2 is easily wetted on the surface of the image carrier and can be expected to have an effect as a lubricant. However, higher alcohol molecules adsorbed on the image carrier, Occupied adsorption area tends to be large, and since the density of molecules adsorbed per unit area of the image carrier (adsorbed molecule weight per unit area) is small, the above-described electrical stress easily penetrates the protective layer. Therefore, it is difficult to obtain the effect of sufficiently protecting the image carrier.

  Further, in a lubricant having a nitrogen atom in the molecule as in the prior art described in Patent Document 3, when the lubricant itself is subjected to the above-described electrical stress, nitrogen oxides and ammonium are decomposed as decomposition products. An ion dissociative compound similar to the contained compound is generated and taken into the lubricating layer, and the lubricating layer may have a low resistance under high humidity, resulting in image blurring.

  In the prior art described in Patent Document 4, fine particles such as silica, titania, alumina, magnesia, zirconia, ferrite and magnetite are added to the solid lubricant mainly composed of zinc stearate on the surface of the photoreceptor. These inorganic fine particles alone cannot greatly improve the toner slip-through, and the charging roller dirt and blade wear do not improve. As a result, the entire image forming apparatus has a short life.

Furthermore, the lubricant described in Patent Document 5 has a protective property from the charging member, and can greatly improve toner slip-through, so that contamination of the charging member can be prevented. However, the protective agent is deposited on the image carrier and filming occurs. In addition, the cleaning member has a property of being greatly worn, and the entire image forming apparatus has a short life.
Further, the protective agent described in Patent Document 6 does not have sufficient protection from charging, and the photoreceptor wear is severe. This wear rate may be 10 times or more that when zinc stearate is used as in Patent Document 1. This wear rate can be reduced to a certain extent by increasing the amount applied to the photoreceptor, but cannot be eliminated completely. Further, it has been found that when the supply amount is increased in this way, the lubricant adheres to the photoreceptor and an abnormal image is generated.

The present invention has been made in view of the above-described problems of the prior art, and provides a sufficient protection effect on the surface of the image carrier, abrasion of the cleaning member, prevention of deterioration, prevention of toner slipping, and application to the image carrier. An object of the present invention is to provide an image carrier protecting agent capable of preventing filming and preventing contamination of a charging member.
Another object of the present invention is to provide a protective layer forming apparatus capable of forming a good image carrier protective layer using the above-mentioned image carrier protective agent.
Furthermore, the present invention provides a sufficient protective effect on the surface of the image carrier by providing the above-described image carrier protective agent, wear of the cleaning member, prevention of deterioration, prevention of toner slipping, and prevention of filming on the image carrier, An object of the present invention is to provide an image forming method and an image forming apparatus capable of preventing the charging member from being contaminated.
Another object of the present invention is to provide an image forming apparatus capable of stably obtaining an image of good quality over a long period of time.
It is another object of the present invention to provide a process cartridge capable of stably obtaining a good quality image and an image forming apparatus including the process cartridge.

In order to achieve the above object, the present invention employs the following solutions.
The first means of the present invention includes at least an image carrier, and an image carrier that is used in an image forming method or an image forming apparatus having a step of applying or adhering an image carrier protective agent to the surface of the image carrier. the dosage, the image bearing member protecting agent, a hydrophobic organic compound (a), the inorganic lubricant (B), and the inorganic fine particles (C), the surface-treated inorganic lubricant (D) viewed including the hydrophobic The organic organic compound (A) is a substance having lamellar crystals, and the hydrophobic organic compound is made of zinc stearate which is a metal salt of a fatty acid, and the inorganic lubricant (B) has a two-dimensional layer structure. The inorganic lubricant (B) is made of boron nitride, the inorganic fine particles (C) are made of alumina particles, and the surface-treated inorganic lubricant (D) contains two inorganic lubricants. A dimensional layer structure, and the surface treatment Inorganic lubricant inorganic lubricant (D), characterized in that it consists of talc or kaolin.
The second means of the present invention is the image-bearing member protecting agent of the mounting serial to the first aspect, the surface treatment of talc or kaolin are inorganic lubricant inorganic lubricant (D) is obtained by the surface treatment, reactive It is a surface treatment with a treating agent having a substituent of

Third means of the present invention is the protective layer forming device configured to apply or attach an image-bearing member protecting agent to the surface of the image bearing member, the image bearing member protecting agent, the mounting serial to the first or second means the image It is a carrier protective agent.
According to a fourth means of the present invention, in the protective layer forming apparatus according to the third means, the image carrier protective agent is supplied to the surface of the image carrier through a supply member.
According to a fifth means of the present invention, in the protective layer forming apparatus according to the third or fourth means, a layer forming member that presses the image carrier protective agent supplied to the surface of the image carrier to form a film. It is characterized by having.

The sixth means of the present invention includes at least an image carrier that has undergone a step of carrying a toner image, transfer means for transferring the toner image on the image carrier to a transfer medium, and the toner image is the transfer medium. In the image forming method having a protective layer forming means for applying or adhering an image carrier protective agent to the surface of the image carrier after being transferred to the image carrier, the image carrier protective agent is described in the first or second means. It is a mounted image carrier protecting agent .

The seventh means of the present invention includes at least an image carrier that has undergone a step of carrying a toner image, a transfer device that transfers the toner image on the image carrier to a transfer medium, and the toner image is the transfer medium. In the image forming apparatus in which a protective layer forming device for applying or adhering the image carrier protecting agent is disposed on the surface of the image carrier after being transferred to the image carrier, the image carrier protecting agent is the first or second means. wherein the serial is an image bearing member protecting agent of the mounting to.
According to an eighth means of the present invention, in the image forming apparatus described in the seventh means, the image is provided on the downstream side of the transfer device and on the upstream side of the protective layer forming device in the moving direction of the surface of the image carrier. A cleaning device is provided for removing toner remaining on the surface of the carrier from the surface by rubbing against the image carrier.
Ninth means of the present invention, in the image forming apparatus mounting the serial to the means of the seventh or eighth, the image bearing member is characterized in that it comprises a thermosetting resin layer which is generated at least on the outermost surface .

According to a tenth means of the present invention, an image carrier is applied to at least an image carrier that has undergone a step of carrying a toner image and the surface of the image carrier after the toner image is transferred to a transfer medium. or in a process cartridge having integrally a protective layer forming device for attaching, characterized in that said image bearing member protecting agent is the image-bearing member protecting agent of the mounting serial to the first or second means.

According to the present invention, by adopting the above-mentioned solution, the problems in the prior art can be solved, and sufficient image carrier surface protection effect, cleaning member wear and deterioration prevention, and toner slip-out prevention. , And an image carrier protective agent capable of preventing filming on the image carrier and preventing contamination of the charging member, and forming a protective layer capable of forming a good image carrier protective layer. An apparatus can be provided.
According to the present invention, by providing the image carrier protective agent, a sufficient effect of protecting the surface of the image carrier, abrasion of the cleaning member, prevention of deterioration, prevention of slipping of toner, and filming on the image carrier. Image forming method and image forming apparatus capable of realizing prevention of contamination and prevention of charging member contamination, and image formation capable of stably obtaining a good quality image over a long period of time An apparatus and a process cartridge can be provided.

Hereinafter, the best mode for carrying out the present invention will be described.
In the image forming method or image forming apparatus according to the present invention, it is essential to have at least a step of having an image carrier and applying or attaching an image carrier protective agent to the surface of the image carrier.
The image carrier protecting agent of the present invention comprises a hydrophobic organic compound (A), an inorganic lubricant (B), inorganic fine particles (C), and a surface-treated inorganic lubricant (D). Yes.

(Image carrier protective agent)
The image carrier protecting agent of the present invention contains the hydrophobic organic compound (A), the inorganic lubricant (B), the inorganic fine particles (C), and the surface-treated inorganic lubricant (D) as described above. And further contains other components as necessary.

  Here, examples of the hydrophobic organic compound (A) contained in the image carrier protecting agent include aliphatic saturated hydrocarbons, aliphatic unsaturated hydrocarbons, alicyclic saturated hydrocarbons, and alicyclic unsaturated hydrocarbons. And hydrocarbons classified as aromatic hydrocarbons, polytetrafluoroethylene (PTFE), polyperfluoroalkyl ether (PFA), perfluoroethylene-perfluoropropylene copolymer (FEP), polyvinylidene fluoride Examples thereof include fluorine resins such as copper (PVdF) and ethylene-tetrafluoroethylene copolymer (ETFE), fluorine waxes, silicone resins such as polymethyl silicone and polymethyl phenyl silicone, and silicone waxes. Typical fatty acids from which the above fatty acid metal salts and stable hydrophobic metal salts are extracted include caproic acid, caprylic acid, enanthylic acid, pelargonic acid, undecylic acid, lauric acid, tridecoic acid, myristylic acid, Palmitic acid, margaric acid, stearic acid, non-cyclic acid, arachidic acid, behenic acid, styringic acid, palmitoleic acid, oleic acid, petricerinic acid, vaccenic acid, linoleic acid, linolenic acid, eleostearic acid, ricanin There are acids, valinal acid, gadoleic acid, arachidonic acid, whale oil and mixtures thereof. Typical stable metal salts of fatty acids include barium stearate, lead stearate, iron stearate, nickel stearate, cobalt stearate, copper stearate, strontium stearate, calcium stearate, cadmium stearate, magnesium stearate , Zinc stearate, zinc oleate, magnesium oleate, iron oleate, cobalt oleate, copper oleate, lead oleate, manganese oleate, zinc palmitate, cobalt palmitate, lead palmitate, magnesium palmitate, palmitate Aluminum oxide, calcium palmitate, lead caprylate, lead caprate, zinc linolenate, cobalt linolenate, calcium linolenate, zinc ricinoleate, cadmium ricinoleate and mixtures thereof There is a thing, but is not limited to this. Moreover, you may mix and use these.

  The inorganic lubricant (B) contained in the image carrier protecting agent is an inorganic lubricant characterized by a two-dimensional layer structure. Examples thereof include talc, mica, boron nitride, molybdenum disulfide, and tungsten disulfide. , Kaolin, smectite, hydrotalcite compound, calcium fluoride, graphite, plate-like alumina, sericite, and synthetic mica, but are not limited thereto. Moreover, you may use these in mixture.

  Further, unlike the two-dimensional layer structure, the inorganic fine particles (C) do not have slipperiness between layers. Examples of this include metal oxides such as silica, tin oxide, zinc oxide, titanium oxide, alumina, zirconium oxide, indium oxide, antimony oxide, bismuth oxide, calcium oxide, antimony-doped tin oxide, tin-doped indium oxide. Products, metal fluorides such as tin fluoride, calcium fluoride, and aluminum fluoride, potassium titanate, and the like, but are not limited thereto. Moreover, you may use these in mixture.

Further, the surface-treated inorganic lubricant (D) is composed of an inorganic lubricant as a base material and a treatment agent that chemically adheres and adsorbs the surface thereof.
The inorganic lubricant in the surface-treated inorganic lubricant (D) is an inorganic substance characterized by a two-dimensional layer structure having properties equivalent to those of the inorganic lubricant (B). Examples thereof include talc, mica, and nitriding. Examples include, but are not limited to, boron, molybdenum disulfide, tungsten disulfide, kaolin, smectite, hydrotalcite compound, calcium fluoride, graphite, plate-like alumina, sericite, and synthetic mica.

  Examples of the surface treatment agent in the surface-treated inorganic lubricant (D) include organic silicon compounds such as methylhydrogenpolysiloxane, silane coupling agents such as vinyltrichlorosilane, vinyltris (βmethoxyethoxy) silane, and vinyltriethoxysilane. , Vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane , Γ− Lucaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, silylating agent such as chlorosilane, dimethyldichlorosilane, vinyldimethylchlorosilane, trichlorosilane, vinyltrichlorosilane, ester silane such as trimethylmethoxysilane, dimethyldimethoxysilane, dimethyldi Examples include ethoxysilane, silazane such as hexamethyldisilazane, siloxane such as hexamethyldisiloxane, octamethylcyclotetrasiloxane, α, ω-dihydroxypolydimethylsiloxane and dimethylpolysiloxysilazane (degree of polymerization: n = 2 to 50). This is not a limitation.

Furthermore, examples of the surface treatment agent include an anionic surfactant, a cationic surfactant, a nonionic surfactant, and the like.
Examples of anionic surfactants include alkylbenzene sulfonate, α-olefin sulfonate, alkane sulfonate, alkyl sulfate, alkyl polyoxyethylene sulfate, alkyl phosphate, long chain fatty acid salt, α -Anion (anion) at the end of the hydrophobic site, such as sulfo fatty acid ester salt and alkyl ether sulfate, and alkali metal ions such as sodium and potassium, and alkaline earth metal ions such as magnesium and calcium Examples thereof include compounds in which metal ions such as aluminum and zinc, ammonium ions, and the like are bonded, but are not limited thereto.

  Examples of cationic surfactants include a cation (cation) at the end of a hydrophobic site, such as alkyltrimethylammonium salt, dialkylmethylammonium salt, alkyldimethylbenzylammonium salt, etc., and chlorine, fluorine , Bromine, and the like, and compounds in which phosphate ions, nitrate ions, sulfate ions, thiosulfate ions, carbonate ions, hydroxide ions, and the like are bonded, are not limited thereto.

  Examples of nonionic surfactants include alcohol compounds such as long-chain alkyl alcohols, alkyl polyoxyethylene ethers, polyoxyethylene alkyl phenyl ethers, fatty acid diethanolamides, alkyl polyglucooxides, polyoxyethylene sorbitan alkyl esters, Examples include ether compounds and amide compounds. In addition, long-chain alkyl carboxylic acids such as lauric acid, palmitic acid, stearic acid, behenic acid, lignoceric acid, serotic acid, montanic acid, and melicic acid, and polyhydric alcohols such as ethylene glycol, propylene glycol, glycerin, erythritol, and hexitol And ester compounds with these partial anhydrides may be mentioned as a preferred form, but are not limited thereto.

  As described above, it is important to use the treatment agent used for the surface treatment, which has a reactive substituent as described above, in consideration of being uniformly fixed to the solid surface of the inorganic lubricant. is there. The reactive group may be directly bonded, or may be indirectly bonded with another substituent.

(Protective layer forming device)
The protective layer forming apparatus of the present invention is an apparatus for applying or adhering an image carrier protective agent to the surface of the image carrier, which is used in the above-described image forming method or image forming apparatus. An image carrier protecting agent comprising a hydrophobic organic compound (A), an inorganic lubricant (B), inorganic fine particles (C), and a surface-treated inorganic lubricant (D) is used. Embodiments of a protective layer forming apparatus according to the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing a main part of an example of the main part of an image forming unit provided with the protective layer forming apparatus of the present invention.
A protective layer forming apparatus 2 disposed opposite to an image carrier (for example, a photoconductor drum) 1 is an image carrier obtained by forming a protective agent for protecting the image carrier 1 into a columnar shape, a quadrangular column shape, a hexagonal column shape, or the like. A protective agent 21; a protective agent supply member 22 that has a brush 22a in contact with the image carrier protective agent 21 and supplies the protective agent transferred from the image carrier protective agent 21 to the brush 22a to the image carrier 1; A pressing force applying mechanism 23 for pressing the carrier protective agent 21 against the brush 22a of the protective agent supply member 22 to transfer the protective agent to the brush 22a of the protective agent supply member 22, and the protective agent supply member 22 on the image carrier. It mainly comprises a protective layer forming mechanism 24 for thinning the supplied protective agent, and a protective agent support member 25 that supports the protective agent 21 so as not to swing back and forth. Further, the image carrier protecting agent 21 used in the present invention includes the hydrophobic organic compound (A), the inorganic lubricant (B), the inorganic fine particles (C), and the surface-treated inorganic lubricant (D) as described above. ), And further contains other components as necessary. A cleaning mechanism 4 is disposed upstream of the protective agent supply member 22 in the moving direction (rotation direction) of the surface of the image carrier indicated by an arrow in the figure. This cleaning mechanism 4 is a protective layer forming device. It can be regarded as a part of 2. Further, the arrangement of the image carrier protecting agent 21 and the protecting agent supply member 22 is merely an example, and is not limited thereto.

In the present invention, in addition to the hydrophobic organic compound (A), the inorganic lubricant (B), and the inorganic fine particles (C), the image carrier protecting agent 21 containing the surface-treated inorganic lubricant (D) is a spring or spring. For example, the contact with the brush-like protective agent supply member 22 is caused by the pressing force from the pressing force applying mechanism 23 formed of a member such as the above. The brush 22a of the protective agent supply member 22 rotates and rubs with the image carrier 1 with a linear velocity difference. At this time, the image carrier protective agent 21 held on the surface of the protective agent supply member is applied to the surface of the image carrier. Supply.
Since the image carrier protective agent 21 supplied to the surface of the image carrier may not be a sufficient protective layer upon supply depending on the selection of the material type, in order to form a more uniform protective layer, for example, in the form of a blade And a protective layer formed on the surface of the image carrier by a protective layer forming mechanism 24 having a member 24a and a pressing member 24b such as a spring or a spring that presses the blade-like member 24a against the surface of the photosensitive drum 1. It becomes.

The image carrier 1 on which the protective layer is formed includes, for example, a charging member (for example, a charging roller) 3 to which a DC voltage or a voltage obtained by superimposing an AC voltage is applied by a voltage applying device such as a high voltage power source (not shown). Then, the image bearing member is charged by discharge in a minute gap in contact with or in close proximity. At this time, a part of the protective layer is decomposed or oxidized due to electrical stress, and air discharge products adhere to the surface of the protective layer, resulting in a deteriorated product.
The deteriorated image carrier protective agent is removed by a cleaning mechanism together with components such as toner remaining on the image carrier by a normal cleaning mechanism. Such a cleaning mechanism may also be used as the protective layer forming mechanism 24 described above. However, the function of removing the image carrier surface residue and the function of forming the protective layer are based on the state of rubbing between appropriate members. In the configuration shown in FIG. 1, the functions are separated, and the cleaning blade 41 and the cleaning pressing mechanism are disposed upstream of the image carrier protecting agent supply unit in the moving direction (rotation direction) of the image carrier 1. A cleaning mechanism (apparatus) 4 composed of 42 and the like is provided.

  The material of the blade-like member (hereinafter referred to as a blade) 24a used in the protective layer forming mechanism 24 is not particularly limited, and for example, urethane rubber, hydrin rubber, silicone rubber generally known as a cleaning blade material. Elastic bodies such as fluoro rubber can be used alone or in a blend. Further, these rubber blades may be coated or impregnated with a low friction coefficient material at the contact portion with the image carrier. Further, in order to adjust the hardness of the elastic body, fillers represented by other organic fillers and inorganic fillers may be dispersed.

These blades are fixed to the blade support 24c by an arbitrary method such as adhesion or fusion so that the tip can be pressed against the surface of the image carrier. The thickness of the blade 24a is not uniquely defined in consideration of the force applied by pressing, but is preferably about 0.5 to 5 mm, more preferably about 1 to 3 mm. .
Also, the length of the cleaning blade that protrudes from the support 24c and can bend, that is, the so-called free length, is not uniquely defined in consideration of the force applied by pressing in the same manner, but is generally 1 to 15 mm. If it is a grade, it can use preferably, and if it is about 2-10 mm, it can use still more preferably.

  As another configuration of the protective layer forming blade member, a layer of resin, rubber, elastomer or the like is coated on the surface of an elastic metal blade such as a spring plate, if necessary, via a coupling agent, a primer component, etc. It may be formed by a method, and if necessary, heat curing or the like, and if necessary, surface polishing or the like may be applied.

The thickness of the elastic metal blade is preferably about 0.05 to 3 mm, and more preferably about 0.1 to 1 mm.
Moreover, in an elastic metal blade, in order to suppress the twist of a blade, you may perform processes, such as a bending process, in the direction substantially parallel to a spindle after attachment.

  As a material for forming the surface layer, fluorine resin such as PFA, PTFE, FEP, PVdF, silicone elastomer such as fluorine rubber, methylphenyl silicone elastomer, and the like can be used together with a filler, if necessary. It is not limited to this.

  Further, the force for pressing the image carrier 1 by the protective layer forming mechanism 24 is sufficient to spread the image carrier protective agent to be in the state of a protective layer or a protective film, and the linear pressure is 5 gf / cm to 80 gf / It is preferably cm or less, and more preferably 10 gf / cm or more and 60 gf / cm or less.

The brush-like member 22a is preferably used as the protective agent supply member 22. In this case, the brush fiber is preferably flexible in order to suppress mechanical stress on the surface of the image carrier.
As a specific material of the flexible brush fiber, one or more kinds selected from generally known materials can be used. Specifically, polyolefin resins (eg, polyethylene, polypropylene); polyvinyl and polyvinylidene resins (eg, polystyrene, acrylic resin, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether, and Polyvinyl chloride); vinyl chloride-vinyl acetate copolymer; styrene-acrylic acid copolymer; styrene-butadiene resin; fluorine resin (for example, polytetrafluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, polychlorotrifluoroethylene); Polyester; Nylon; Acrylic; Rayon; Polyurethane; Polycarbonate; Phenol resin; Amino resin (eg urea-formaldehyde resin, melamine) Fat, benzoguanamine resins, urea resins, polyamide resins); Among such, may be a resin having flexibility.

  Also, in order to adjust the degree of bending, diene rubber, styrene-butadiene rubber (SBR), ethylene propylene rubber, isoprene rubber, nitrile rubber, urethane rubber, silicone rubber, hydrin rubber, norbornene rubber, etc. are used in combination. Also good.

The support 22b of the brush 22a of the protective agent supply member 22 includes a fixed mold and a rotatable roll. As the roll-shaped supply member, for example, there is a roll brush in which a tape having brush fibers piled is wound around a metal core in a spiral shape. The brush fiber has a fiber diameter of about 10 to 500 μm, the length of the brush fiber is 1 to 15 mm, and the brush density is 10,000 to 300,000 per square inch (1.5 × 10 ^{7 to} 4.5 × 10 per square meter). ⁸ ) are preferably used.

  The protective agent supply member 22 is preferably made of a material having a very high brush density in terms of supply uniformity and stability, and one fiber is made from several to several hundreds of fine fibers. Is also preferable. For example, bundling 50 fine fibers of 6.7 decitex (6 denier), such as 333 decitex = 6.7 decitex × 50 filament (300 denier = 6 denier × 50 filament), and implanting as one fiber Is also possible.

  Moreover, you may provide a coating layer in the brush surface for the purpose of stabilizing the surface shape of a brush, environmental stability, etc. as needed. As a component constituting the coating layer, it is preferable to use a coating layer component that can be deformed according to the bending of the brush fiber, and these are not limited as long as the material can maintain flexibility. Polyolefin resins such as polyethylene, polypropylene, chlorinated polyethylene, chlorosulfonated polyethylene, etc .; polystyrene, acrylic (for example, polymethyl methacrylate), polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, Polyvinyl and polyvinylidene resins such as polyvinyl carbazole, polyvinyl ether, and polybiliketones; vinyl chloride-vinyl acetate copolymers; silicone resins composed of organosiloxane bonds or modified products thereof (for example, alkyd resins, Modified products by reester resin, epoxy resin, polyurethane, etc.); Fluorine resins such as perfluoroalkyl ether, polyfluorovinyl, polyfluorovinylidene, polychlorotrifluoroethylene; polyamide; polyester; polyurethane; polycarbonate; urea-formaldehyde resin, etc. Amino resins; epoxy resins, composite resins of these, and the like.

(Process cartridge)
Next, an embodiment of a process cartridge according to the present invention will be described.
The process cartridge of the present invention comprises at least the image carrier and the protective layer forming apparatus 2 of the present invention, and further, if necessary, charging means, exposure means, developing means, transfer means, cleaning means, static elimination. It has other means such as means.
The process cartridge of the present invention can be detachably provided in various electrophotographic apparatuses, and is preferably provided detachably in the image forming apparatus of the present invention described later.

Here, FIG. 2 is a schematic cross-sectional view for explaining an outline of a configuration example of a process cartridge using the protective layer forming apparatus of the present invention. This process cartridge is an image forming unit of the image forming apparatus according to the present invention. 10 is detachably provided.
An image forming unit 10 shown in FIG. 2 includes an image carrier (for example, a photosensitive drum) 1, a charging device (charging roller in the illustrated example) 3 that is a charging unit that charges the image carrier 1, and a charged image. An electrostatic latent image forming means (not shown) for forming an electrostatic latent image by irradiating the carrier 1 with a laser beam L or the like, and developing the electrostatic latent image on the image carrier 1 with toner to make it visible A developing device 5 which is a developing means for forming an image (toner image), a transfer means 6 for transferring a toner image on the image carrier 1 to a transfer medium (recording medium such as paper or an intermediate transfer body) 7, and after transfer The cleaning device 4 is a cleaning unit that removes toner remaining on the surface of the image carrier 1, and the protective layer forming device 2 is disposed in a portion from the cleaning device 4 to the charging device 3. The image forming unit 10 is configured using a process cartridge 11 in which a protective layer forming device 2, a charging device 3, a developing device 5, and a cleaning device 4 are integrally provided in a cartridge together with the image carrier 1. Yes. In the present embodiment, the cleaning device 4 cleans the surface of the photosensitive member before supplying the protective agent so that the protective agent is satisfactorily applied. Therefore, the moving direction of the image carrier 1 ( It is provided on the downstream side of the transfer means 6 in the rotation direction) and on the upstream side of the protective layer forming apparatus 2.

In the process cartridge 11, the protective layer forming device 2 disposed facing the photosensitive drum as the image carrier 1 includes an image carrier protective agent 21, a protective agent supply member 22, a pressing force applying member 23, It comprises a protective layer forming member 24, a protective agent support member 25, and the like.
Further, the image carrier 1 has a surface on which the protective agent for the image carrier and the toner component partially deteriorated after the transfer process remain, but the surface residue is cleaned by the cleaning member 41 of the cleaning device 4. To be cleaned.
In FIG. 2, the cleaning member 41 is a cleaning blade abutted at an angle similar to a so-called counter type (leading type). The blade 24a of the protective layer forming mechanism 24 is not a counter type in the illustrated example, but the blade 24a may also be brought into contact with an angle similar to the counter type.

The image carrier protective agent 21 is supplied from the protective agent supply member 22 of the protective layer forming device 2 to the surface of the image carrier from which the residual toner on the surface and the deteriorated protective agent for the image carrier are removed by the cleaning device 4. Then, the protective layer forming mechanism 24 forms a film-like protective layer. At this time, the image carrier protecting agent 21 used in the present invention can stably and stably supply the necessary and sufficient amount to the surface of the image carrier with good controllability. Thus, the deterioration of the image carrier itself can be prevented.
The image carrier 1 having the protective layer formed in this way is charged by the charging device (charging roller) 3, and then an electrostatic latent image is formed by exposure L such as a laser, and is developed by the developing device 5 to be visible. An image is formed and transferred to a transfer medium (recording medium such as paper or an intermediate transfer member) 7 by transfer means (transfer roller or the like) 6 outside the process cartridge.

  As described above, the process cartridge 11 of the present invention has an excellent tolerance for fluctuations in the surface state of the image carrier, and has a configuration in which fluctuations in charging performance to the image carrier are highly suppressed. By using the cartridge 11 in the image forming unit of the image forming apparatus, it is possible to stably form an extremely high quality image over a long period of time.

(Image forming apparatus and image forming method)
The image forming apparatus of the present invention includes an image carrier, an electrostatic latent image forming unit, a developing unit, a transfer unit, a protective layer forming unit (the protective layer forming device 2 of the present invention described above), and a fixing unit. At least, preferably a cleaning means, and other means appropriately selected as necessary, for example, a static elimination means, a recycling means, a control means and the like.
The image forming method of the present invention includes at least an electrostatic latent image forming step, a developing step, a transfer step, a protective layer forming step, and a fixing step, preferably including a cleaning step, and further appropriately as necessary. It includes other selected processes such as a static elimination process, a recycling process, and a control process.

  The image forming method of the present invention can be preferably carried out by the image forming apparatus of the present invention, the electrostatic latent image forming step can be performed by the electrostatic latent image forming means, and the developing step is the developing The transfer step can be performed by the transfer unit, the protective layer forming step can be performed by the protective layer forming unit (the protective layer forming apparatus 2 of the present invention described above), The fixing step can be performed by the fixing unit, and the other steps can be performed by the other unit.

<Electrostatic latent image forming step and electrostatic latent image forming means>
The electrostatic latent image forming step is a step of forming an electrostatic latent image on the image carrier.
-Image carrier-
The image carrier (sometimes referred to as “electrostatic latent image carrier” or “photoreceptor”) is not particularly limited in terms of material, shape, structure, size, etc., and is appropriately selected from known ones. The shape is preferably a drum shape, and examples of the material include inorganic photoconductors such as amorphous silicon and selenium, and organic photoconductors such as polysilane and phthalopolymethine.

The image carrier (photoreceptor) used in the image forming apparatus of the present invention has a conductive support and at least a photosensitive layer on the conductive support, and further has other layers as necessary. It becomes.
As the photosensitive layer, a single layer type in which a charge generation material and a charge transport material are mixed, a forward layer type in which a charge transport layer is provided on the charge generation layer, or a charge generation layer is provided on the charge transport layer. There is a reverse layer type. In order to improve the mechanical strength, abrasion resistance, gas resistance, cleaning property, etc. of the photoreceptor, an outermost surface layer can be provided on the photosensitive layer. An undercoat layer may be provided between the photosensitive layer and the conductive support. Moreover, an appropriate amount of a plasticizer, an antioxidant, a leveling agent or the like can be added to each layer as necessary.

The conductive support is not particularly limited as long as it has a volume resistance of 1.0 × 10 ¹⁰ Ω · cm or less, and can be appropriately selected according to the purpose. For example, aluminum, Metals such as nickel, chromium, nichrome, copper, gold, silver and platinum, metal oxides such as tin oxide and indium oxide, film or cylindrical plastic, paper coated or aluminum by vapor deposition or sputtering A plate made of aluminum alloy, nickel, stainless steel or the like, and a tube processed into a drum shape by a method such as extrusion or drawing, and then subjected to surface treatment such as cutting, superfinishing, or polishing can be used.

The drum-shaped support preferably has a diameter of 20 to 150 mm, more preferably 24 to 100 mm, and still more preferably 28 to 70 mm. When the diameter of the drum-shaped support is less than 20 mm, it may be physically difficult to arrange each step of charging, exposure, development, transfer, and cleaning around the drum. When the diameter exceeds 150 mm, The image forming apparatus may become large. In particular, when the image forming apparatus is a tandem type, since it is necessary to mount a plurality of photoconductors, the diameter is preferably 70 mm or less, and more preferably 60 mm or less.
Further, an endless nickel belt or an endless stainless steel belt as disclosed in JP-A-52-36016 can also be used as the conductive support.

The undercoat layer of the photoconductor may be composed of a single layer or a plurality of layers. For example, (1) the resin is the main component, and (2) the white pigment and the resin are the main components. And (3) a metal oxide film obtained by chemically or electrochemically oxidizing the surface of a conductive substrate. Among these, those containing a white pigment and a resin as main components are preferable.
Examples of the white pigment include metal oxides such as titanium oxide, aluminum oxide, zirconium oxide, and zinc oxide. Among these, titanium oxide is particularly preferable because it is excellent in preventing injection of charges from the conductive support.
Examples of the resin include thermoplastic resins such as polyamide, polyvinyl alcohol, casein, and methyl cellulose; thermosetting resins such as acrylic, phenol, melamine, alkyd, unsaturated polyester, and epoxy. These may be used individually by 1 type and may use 2 or more types together.
There is no restriction | limiting in particular in the thickness of the said undercoat layer, According to the objective, it can select suitably, 0.1-10 micrometers is preferable and 1-5 micrometers is more preferable.

  Examples of the charge generation material in the photosensitive layer include monoazo pigments, bisazo pigments, trisazo pigments, tetrakisazo pigments and other azo pigments, triarylmethane dyes, thiazine dyes, oxazine dyes, xanthene dyes, Cyanine dyes, styryl dyes, pyrylium dyes, quinacridone pigments, indigo pigments, perylene pigments, polycyclic quinone pigments, bisbenzimidazole pigments, indanthrone pigments, squarylium pigments, phthalocyanine pigments, etc. Organic pigments or dyes; selenium, selenium-arsenic, selenium-tellurium, cadmium sulfide, zinc oxide, titanium oxide, amorphous silicon, and other inorganic materials. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the charge transport material in the photosensitive layer include anthracene derivatives, pyrene derivatives, carbazole derivatives, tetrazole derivatives, metallocene derivatives, phenothiazine derivatives, pyrazoline compounds, hydrazone compounds, styryl compounds, styryl hydrazone compounds, enamine compounds, butadiene compounds, distyryl. Examples thereof include compounds, oxazole compounds, oxadiazole compounds, thiazole compounds, imidazole compounds, triphenylamine derivatives, phenylenediamine derivatives, aminostilbene derivatives, and triphenylmethane derivatives. These may be used individually by 1 type and may use 2 or more types together.

  As the binder resin used to form the photosensitive layer, it is electrically insulating and may be a known thermoplastic resin, thermosetting resin, photocurable resin, photoconductive resin, or the like. it can. Examples of the binder resin include polyvinyl chloride, polyvinylidene chloride, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, ethylene-vinyl acetate copolymer, polyvinyl butyral, Polyvinyl acetal, polyester, phenoxy resin, (meth) acrylic resin, polystyrene, polycarbonate, polyarylate, polysulfone, polyethersulfone, ABS resin and other thermoplastic resins, phenol resin, epoxy resin, urethane resin, melamine resin, isocyanate Examples thereof include thermosetting resins such as resins, alkyd resins, silicone resins, thermosetting acrylic resins, polyvinyl carbazole, polyvinyl anthracene, and polyvinyl pyrene. These may be used individually by 1 type and may use 2 or more types together.

Examples of the antioxidant include phenolic compounds, paraphenylenediamines, organic sulfur compounds, and organic phosphorus compounds.
Examples of the phenol compound include 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, stearyl-β- (3, 5-di-t-butyl-4-hydroxyphenyl) propionate, 2,2'-methylene-bis- (4-methyl-6-t-butylphenol), 2,2'-methylene-bis- (4-ethyl- 6-t-butylphenol), 4,4′-thiobis- (3-methyl-6-tert-butylphenol), 4,4′-butylidenebis- (3-methyl-6-tert-butylphenol), 1,1,3 -Tris- (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxy Ben ) Benzene, tetrakis- [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane, bis [3,3′-bis (4′-hydroxy-3 ′) -T-butylphenyl) butyric acid] cricol ester, tocopherols and the like.
Examples of the paraphenylenediamines include N-phenyl-N′-isopropyl-p-phenylenediamine, N, N′-di-sec-butyl-p-phenylenediamine, N-phenyl-N-sec-butyl- Examples include p-phenylenediamine, N, N′-di-isopropyl-p-phenylenediamine, N, N′-dimethyl-N, N′-di-t-butyl-p-phenylenediamine, and the like.
Examples of the hydroquinones include 2,5-di-t-octyl hydroquinone, 2,6-didodecyl hydroquinone, 2-dodecyl hydroquinone, 2-dodecyl-5-chlorohydroquinone, 2-t-octyl-5-methyl. Examples include hydroquinone and 2- (2-octadecenyl) -5-methylhydroquinone.
Examples of the organic sulfur compounds include dilauryl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, ditetradecyl-3,3′-thiodipropionate, and the like. .
Examples of the organic phosphorus compounds include triphenylphosphine, tri (nonylphenyl) phosphine, tri (dinonylphenyl) phosphine, tricresylphosphine, tri (2,4-dibutylphenoxy) phosphine, and the like.
These compounds are known as antioxidants such as rubbers, plastics and fats and oils, and commercially available products can be easily obtained.
The addition amount of the antioxidant is preferably 0.01 to 10% by mass with respect to the total mass of the layer to be added.

As the plasticizer, those used as plasticizers for general resins such as dibutyl phthalate and dioctyl phthalate can be used as they are, and the amount used is about 0 to 30 parts by mass with respect to 100 parts by mass of the binder resin. Is appropriate.
Further, a leveling agent may be added to the photosensitive layer. Examples of the leveling agent include silicone oils such as dimethyl silicone oil and methylphenyl silicone oil; polymers having a perfluoroalkyl group in the chain or oligomers. As for the usage-amount of the said leveling agent, 0-1 mass part is preferable with respect to 100 mass parts of said binder resins.

  Next, the formation of the electrostatic latent image can be performed, for example, by uniformly charging the surface of the image carrier and then performing imagewise exposure, and by the electrostatic latent image forming unit. Can do. The electrostatic latent image forming means includes, for example, charging means for uniformly charging the surface of the image carrier (the charging device 3), and exposure means (laser) for exposing the surface of the image carrier imagewise. Exposure means such as light).

The charging can be performed, for example, by applying a voltage to the surface of the image carrier 1 using the charging device 3.
The charging device is not particularly limited and may be appropriately selected depending on the purpose. For example, the charging device known per se provided with a conductive or semiconductive roller, brush, film, rubber blade, etc. And non-contact chargers utilizing corona discharge such as corotrons and corotrons.
The charging device preferably has voltage applying means for applying a voltage having an AC component.

The exposure can be performed, for example, by exposing the surface of the image carrier imagewise using the exposure unit.
The exposure means is not particularly limited as long as it can expose the surface of the image carrier 1 charged by the charging device 3 like an image to be formed, and may be appropriately selected according to the purpose. Examples thereof include various exposure apparatuses such as a copying optical system, a rod lens array system, a laser optical system, a liquid crystal shutter optical system, and an LED array optical system.
In the present invention, an optical back side system in which imagewise exposure is performed from the back side of the image carrier may be adopted.

<Development process and development means>
The developing step is a step of developing the electrostatic latent image using a toner or a developer to form a visible image.
The visible image can be formed, for example, by developing the electrostatic latent image using the toner or the developer, and can be performed by the developing unit.
The developing unit is not particularly limited as long as it can be developed using, for example, the toner or the developer, and can be appropriately selected from known ones. For example, the toner or developer is accommodated. A preferable example includes at least a developing device capable of applying the toner or the developer to the electrostatic latent image in a contact or non-contact manner.

-Toner-
The toner preferably has an average circularity of 0.93 to 1.00, and more preferably 0.95 to 0.99, which is an average value of the circularity SR represented by the following formula 1. This average circularity is an index of the degree of unevenness of toner particles, and indicates 1.00 when the toner is a perfect sphere, and the average circularity becomes smaller as the surface shape becomes more complicated.
Circularity SR = perimeter of a circle having the same area as the particle projection area / perimeter of the particle projection image (Formula 1)

  When the average circularity is in the range of 0.93 to 1.00, the surface of the toner particles is smooth, and the toner particles and the contact area between the toner particles and the photosensitive member are small, so that the transferability is excellent. Further, since the toner particles have no corners, the developer agitation torque in the developing device is small, and the agitation drive is stabilized, so that no abnormal image is generated. In addition, since there are no angular toner particles in the toner that forms the dots, the pressure is uniformly applied to the entire toner that forms the dots when pressed against the recording medium during transfer, and the transfer is not easily lost. Further, since the toner particles are not angular, the abrasive power of the toner particles themselves is small, and the surface of the image carrier is not damaged or worn.

The circularity SR can be measured using, for example, a flow particle image analyzer (manufactured by Toa Medical Electronics Co., Ltd., FPIA-1000).
First, 0.1 to 0.5 ml of a surfactant (preferably alkylbenzene sulfonate) is added as a dispersant to 100 to 150 ml of water from which impure solids have been removed in advance. Add ~ 0.5g. The suspension in which the sample is dispersed is subjected to dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the shape and particle size of the toner are measured by the above apparatus with the dispersion concentration being 3000 to 10000 / μl.

The weight average particle diameter (D4) of the toner is preferably 3 to 10 μm, and more preferably 4 to 8 μm. In this range, since the toner particles have a sufficiently small particle size with respect to the minute latent image dots, the dot reproducibility is excellent. If the weight average particle diameter (D4) is less than 3 μm, phenomena such as a decrease in transfer efficiency and a decrease in blade cleaning properties may occur, and if it exceeds 10 μm, it may be difficult to suppress scattering of characters and lines. is there.
In the toner, the ratio (D4 / D1) of the weight average particle diameter (D4) to the number average particle diameter (D1) is preferably 1.00 to 1.40, more preferably 1.00 to 1.30. This means that the closer the ratio (D4 / D1) is to 1, the sharper the particle size distribution of the toner. Since image quality does not occur, the image quality is excellent. In addition, since the toner particle size distribution is sharp, the triboelectric charge amount distribution is also sharp and the occurrence of fog is suppressed. Further, when the toner particle diameter is uniform, the latent image dots are developed so as to be arranged densely and orderly, so that the dot reproducibility is excellent.

Here, the weight average particle diameter (D4) and the particle size distribution of the toner are measured by, for example, a Coulter counter method. Examples of the measuring device for the particle size distribution of toner particles by the Coulter counter method include Coulter Counter TA-II and Coulter Multisizer II (both manufactured by Coulter).
First, 0.1 to 5 ml of a surfactant (preferably alkyl benzene sulfonate) is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution. Here, the electrolytic solution is a solution prepared by preparing a 1% NaCl aqueous solution using primary sodium chloride. For example, ISOTON-II (manufactured by Coulter) can be used. Here, 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes. Volume distribution and number distribution are calculated. From the obtained distribution, the weight average particle diameter (D4) and the number average particle diameter (D1) of the toner can be obtained.
As channels, 2.00 to less than 2.52 μm; 2.52 to less than 3.17 μm; 3.17 to less than 4.00 μm; 4.00 to less than 5.04 μm; 5.04 to less than 6.35 μm; 6 Less than 35 to 8.00 μm; less than 8.00 to less than 10.08 μm; less than 10.08 to less than 12.70 μm; less than 12.70 to less than 16.00 μm; less than 16.00 to less than 20.20 μm; Uses 13 channels of less than 40 μm; 25.40 to less than 32.00 μm; 32.00 to less than 40.30 μm, and targets particles having a particle size of 2.00 μm to less than 40.30 μm.

  As the toner having such a substantially spherical shape, a toner composition containing a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent is crosslinked in the presence of resin fine particles in an aqueous medium. It can be prepared by an extension reaction. The toner manufactured by this reaction can reduce the hot offset by curing the surface of the toner, and it can be suppressed that the fixing device becomes dirty and appears on the image.

Examples of the prepolymer made of the modified polyester resin include a polyester prepolymer (A) having an isocyanate group, and examples of the compound that extends or crosslinks with the prepolymer include amines (B).
Examples of the polyester prepolymer (A) having an isocyanate group include a polycondensate of a polyol (1) and a polycarboxylic acid (2) and a polyester having an active hydrogen group, which is further reacted with a polyisocyanate (3). Is mentioned. Examples of active hydrogen groups possessed by the polyester include hydroxyl groups (alcoholic hydroxyl groups and phenolic hydroxyl groups), amino groups, carboxyl groups, mercapto groups, and the like. Among these, alcoholic hydroxyl groups are particularly preferable.

Examples of the polyol (1) include diol (1-1), trivalent or higher polyol (1-2), (1-1) alone or (1-1) and a small amount of (1-2). Mixtures are preferred.
Examples of the diol (1-1) include alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycol (Diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); Alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); Bisphenols (bisphenol A) Bisphenol F, bisphenol S, etc.); alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the above alicyclic diol Alkylene oxide of the bisphenols (ethylene oxide, propylene oxide, butylene oxide, etc.), etc. adducts. Among these, alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols are preferable, and combined use of alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms is particularly preferable.

  Examples of the trivalent or higher polyol (1-2) include 3 to 8 or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); (Trisphenol PA, phenol novolak, cresol novolak, etc.); alkylene oxide adducts of the above trivalent or higher polyphenols.

Examples of the polycarboxylic acid (2) include dicarboxylic acid (2-1) and trivalent or higher polycarboxylic acid (2-2). Among these, (2-1) alone and (2-1) ) And a small amount of (2-2).
Examples of the dicarboxylic acid (2-1) include alkylene dicarboxylic acids (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acids (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acids (phthalic acid, isophthalic acid, Terephthalic acid, naphthalenedicarboxylic acid, etc.). Among these, alkenylene dicarboxylic acid having 4 to 20 carbon atoms and aromatic dicarboxylic acid having 8 to 20 carbon atoms are particularly preferable.
Examples of the trivalent or higher polycarboxylic acid (2-2) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid). In addition, as polycarboxylic acid (2), you may make it react with polyol (1) using the acid anhydride or lower alkyl ester (methyl ester, ethyl ester, isopropyl ester, etc.) of the above-mentioned thing.

  As for the ratio of the polyol (1) and the polycarboxylic acid (2), the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH] is preferably 2/1 to 1/1. 5/1 to 1/1 is more preferable, and 1.3 / 1 to 1.02 / 1 is still more preferable.

  Examples of the polyisocyanate (3) include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.) Aromatic diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanurates; Those blocked with caprolactam, etc. These may be used individually by 1 type and may use 2 or more types together.

  As for the ratio of the polyisocyanate (3), the equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group is preferably 5/1 to 1/1. 1 to 1.2 / 1 is more preferable, and 2.5 / 1 to 1.5 / 1 is still more preferable. If the [NCO] / [OH] exceeds 5, the low-temperature fixability may be deteriorated. If the molar ratio of [NCO] is less than 1, the urea content in the modified polyester becomes low, and hot offset resistance Sex worsens.

  The content of the polyisocyanate (3) component in the prepolymer (A) having an isocyanate group at the terminal is preferably 0.5 to 40% by mass, more preferably 1 to 30% by mass, and 2 to 20% by mass. Is more preferable. When the content is less than 0.5% by mass, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. When the content exceeds 40% by mass, low-temperature fixability is obtained. May get worse.

The average number of isocyanate groups contained per molecule in the prepolymer (A) having the isocyanate group is preferably 1 or more, more preferably 1.5 to 3 on average, and 1.8 to 2.5 on average. Further preferred. When the number is less than 1 per molecule, the molecular weight of the urea-modified polyester is lowered, and the hot offset resistance may be deteriorated.

  As the amines (B), the diamine (B1), trivalent or higher polyamine (B2), amino alcohol (B3), amino mercaptan (B4), amino acid (B5), and amino groups of B1 to B5 were blocked. (B6) etc. are mentioned. Examples of the diamine (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′dimethyldicyclohexylmethane, diaminecyclohexane, Isophorone diamine etc.); and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine etc.) and the like. Examples of the trivalent or higher polyamine (B2) include diethylenetriamine and triethylenetetramine. Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid. Examples of the B1-B5 amino group blocked (B6) include ketimine compounds and oxazoline compounds obtained from the B1-B5 amines and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). Among these amines (B), preferred are B1 and a mixture of B1 and a small amount of B2.

  Furthermore, if necessary, the molecular weight of the urea-modified polyester can be adjusted using an elongation terminator. Examples of the elongation terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), or those obtained by blocking them (ketimine compounds).

The ratio of the amines (B) is the equivalent ratio [NCO] / [NHx] of the isocyanate group [NCO] in the prepolymer (A) having an isocyanate group and the amino group [NHx] in the amine (B). Is preferably 1/2 to 2/1, more preferably 1.5 / 1 to 1 / 1.5, and still more preferably 1.2 / 1 to 1 / 1.2. When the [NCO] / [NHx] exceeds 2 or is less than 1/2, the molecular weight of the urea-modified polyester (i) becomes low, and the hot offset resistance deteriorates.
In the present invention, the polyester (i) modified with a urea bond may contain a urethane bond together with a urea bond. The molar ratio between the urea bond content and the urethane bond content is preferably 100/0 to 10/90, more preferably 80/20 to 20/80, and still more preferably 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance may be deteriorated.

By these reactions, the modified polyester used in the toner, especially the urea-modified polyester (i) can be produced. These urea-modified polyesters (i) are produced by a one-shot method or a prepolymer method. The mass average molecular weight of the urea-modified polyester (i) is preferably 10,000 or more, more preferably 20,000 to 10,000,000, and still more preferably 30,000 to 1,000,000. When the mass average molecular weight is less than 10,000, the hot offset resistance may be deteriorated.
The number average molecular weight of the urea-modified polyester is not particularly limited when the unmodified polyester (ii) described later is used, and may be a number average molecular weight that can be easily obtained to obtain the mass average molecular weight. (I) When used alone, the number average molecular weight is preferably 20,000 or less, more preferably 1,000 to 10,000, and still more preferably 2,000 to 8,000. When the number average molecular weight exceeds 20,000, low temperature fixability and glossiness when used in a full color image forming apparatus may be deteriorated.

In the present invention, not only the polyester (i) modified with a urea bond but also the polyester (ii) not modified can be included as a binder resin component together with the (i). By using (ii) in combination, the low-temperature fixability and the gloss when used in a full-color apparatus are improved, so that it is preferable to use alone. Examples of (ii) include the same polycondensates of polyol (1) and polycarboxylic acid (2) as in the polyester component (i), and preferred ones are also the same as (i). Further, (ii) is not limited to unmodified polyester, but may be modified with a chemical bond other than a urea bond, for example, may be modified with a urethane bond. It is preferable that (i) and (ii) are at least partially compatible with each other in terms of low-temperature fixability and hot offset resistance.
Therefore, the polyester component (i) and (ii) preferably have similar compositions. When (ii) is contained, the mass ratio of (i) and (ii) is preferably 5/95 to 80/20, more preferably 5/95 to 30/70, and further preferably 5/95 to 25/75. 7/93 to 20/80 is particularly preferable. When the mass ratio of (i) is less than 5% by mass, the hot offset resistance may be deteriorated, and it may be disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

  The peak molecular weight of (ii) is preferably 1,000 to 30,000, more preferably 1,500 to 10,000, and still more preferably 2,000 to 8,000. When the peak molecular weight is less than 1,000, the heat resistant storage stability may be deteriorated, and when it exceeds 10,000, the low temperature fixability may be deteriorated. The hydroxyl value of (ii) is preferably 5 or more, more preferably 10 to 120, and still more preferably 20 to 80. If the hydroxyl value is less than 5, it may be disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. 1-30 are preferable and, as for the acid value of said (ii), 5-20 are more preferable. By having an acid value, it tends to be negatively charged.

The glass transition temperature (Tg) of the binder resin is preferably 50 to 70 ° C, and more preferably 55 to 65 ° C. When the glass transition temperature is less than 50 ° C., blocking of the toner during high temperature storage may deteriorate, and when it exceeds 70 ° C., the low temperature fixability becomes insufficient. Due to the coexistence of the urea-modified polyester resin, the toner used in the present invention tends to have good heat storage stability even when the glass transition point is low, as compared with known polyester-based toners.
As the storage elastic modulus of the binder resin, the temperature (TG ′) at which the measurement frequency is 20 Hz is 10,000 dyne / cm 2 is preferably 100 ° C. or more, and more preferably 110 to 200 ° C. When the temperature (TG ′) is less than 100 ° C., the hot offset resistance may be deteriorated.
As the viscosity of the binder resin, the temperature (Tη) at 1000 poise at a measurement frequency of 20 Hz is preferably 180 ° C. or less, and more preferably 90 to 160 ° C. When the temperature (Tη) exceeds 180 ° C., the low-temperature fixability deteriorates. That is, TG ′ is preferably higher than Tη from the viewpoint of achieving both low temperature fixability and hot offset resistance. In other words, the difference between TG ′ and Tη (TG′−Tη) is preferably 0 ° C. or higher, more preferably 10 ° C. or higher, and still more preferably 20 ° C. or higher. The upper limit of the difference is not particularly limited. Further, from the viewpoint of achieving both heat-resistant storage stability and low-temperature fixability, the difference between Tη and Tg is preferably 0 to 100 ° C, more preferably 10 to 90 ° C, and still more preferably 20 to 80 ° C.

The binder resin can be produced by the following method.
First, the polyol (1) and the polycarboxylic acid (2) are produced at 150 to 280 ° C. in the presence of a known esterification catalyst such as tetrabutoxytitanate or dibutyltin oxide, and reduced pressure as necessary. Water is distilled off to obtain a polyester having a hydroxyl group. Subsequently, this is made to react with polyisocyanate (3) at 40-140 degreeC, and the prepolymer (A) which has an isocyanate group is obtained. Further, (A) is reacted with amines (B) at 0 to 140 ° C. to obtain a polyester modified with a urea bond. When reacting (3) and reacting (A) and (B), a solvent may be used as necessary.
Usable solvents include, for example, aromatic solvents (toluene, xylene, etc.); ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.); esters (ethyl acetate, etc.); amides (dimethylformamide, dimethylacetamide, etc.), Inactive to isocyanate (3) such as ethers (tetrahydrofuran, etc.).
When using polyester (ii) not modified with urea bond, (ii) is produced in the same manner as polyester having a hydroxyl group, and this is dissolved in the solution after completion of the reaction of (i). , Mix.

Further, the toner used in the present invention can be produced by the following method, but is not limited thereto.
The toner may be formed by reacting a dispersion made of a prepolymer (A) having an isocyanate group in an aqueous medium with (B), or using a urea-modified polyester (i) produced in advance. Good. As a method for stably forming a dispersion comprising urea-modified polyester (i) or prepolymer (A) in an aqueous medium, a toner raw material comprising urea-modified polyester (i) or prepolymer (A) in an aqueous medium is used. And a method of dispersing by shearing force.
The prepolymer (A) and other toner compositions (hereinafter sometimes referred to as toner raw materials), colorants, colorant master batches, release agents, charge control agents, unmodified polyester resins, Mixing may be performed when the dispersion is formed in the medium, but it is more preferable to mix the toner raw materials in advance and then add and disperse the mixture in the aqueous medium. In the present invention, other toner raw materials such as a colorant, a release agent, and a charge control agent do not necessarily have to be mixed when forming particles in an aqueous medium. It may be added later. For example, after forming particles not containing a colorant, the colorant can be added by a known dyeing method.
As the aqueous medium, water alone may be used, but a solvent miscible with water may be used in combination. Examples of miscible solvents include alcohols (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.), and the like.

  The amount of the aqueous medium used relative to 100 parts by mass of the toner composition containing the urea-modified polyester (i) and the prepolymer (A) is preferably 50 to 2000 parts by mass, and more preferably 100 to 1000 parts by mass. When the amount used is less than 50 parts by mass, the toner composition is not well dispersed, and toner particles having a predetermined particle size may not be obtained. When the amount used exceeds 2000 parts by mass, it is not economical.

Moreover, a dispersing agent can also be used as needed. It is preferable to use a dispersant because the particle size distribution becomes sharp and the dispersion is stable.
The dispersion method is not particularly limited and may be appropriately selected depending on the intended purpose. For example, known equipment such as a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, and an ultrasonic wave can be applied. . In order to make the particle diameter of the dispersion 2 to 20 μm, a high-speed shearing method is preferable. When a high-speed shearing disperser is used, the number of rotations is not particularly limited, but is preferably 1000 to 30000 rpm, more preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 5 minutes. As temperature at the time of dispersion | distribution, 0-150 degreeC is preferable normally and 40-98 degreeC is more preferable. Higher temperatures are preferred in that the dispersion made of urea-modified polyester (i) or prepolymer (A) has a low viscosity and is easy to disperse.

  In the step of synthesizing the urea-modified polyester (i) from the prepolymer (A), the amine (B) may be added and reacted before the toner composition is dispersed in the aqueous medium, or may be dispersed in the aqueous medium. An amine (B) may be added later to cause a reaction from the particle interface. In this case, urea-modified polyester is preferentially produced on the surface of the manufactured toner, and a concentration gradient can be provided inside the particles.

In the reaction, it is preferable to use a dispersant as necessary.
There is no restriction | limiting in particular as said dispersing agent, According to the objective, it can select suitably, For example, surfactant, a slightly water-soluble inorganic compound dispersing agent, a polymeric protective colloid, etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, surfactants are preferable.

Examples of the surfactant include an anionic surfactant, a cationic surfactant, a nonionic surfactant, and an amphoteric surfactant.
Examples of the anionic surfactant include alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters, and the like. Among these, those having a fluoroalkyl group are preferable. Examples of the anionic surfactant having a fluoroalkyl group include a fluoroalkylcarboxylic acid having 2 to 10 carbon atoms or a metal salt thereof, disodium perfluorooctanesulfonylglutamate, 3- [omega-fluoroalkyl (6 carbon atoms). -11) Oxy] -1-alkyl (carbon number 3-4) sodium sulfonate, 3- [omega-fluoroalkanoyl (carbon number 6-8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (Carbon number 11-20) carboxylic acid or its metal salt, perfluoroalkyl carboxylic acid (carbon number 7-13) or its metal salt, perfluoroalkyl (carbon number 4-12) sulfonic acid or its metal salt, perfluoro Octanesulfonic acid diethanolamide, N-propyl-N- (2-hydroxy Ethyl) perfluorooctanesulfonamide, perfluoroalkyl (carbon number 6-10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (carbon number 6-10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (carbon number) 6-16) Ethyl phosphate and the like. Examples of commercially available surfactants having a fluoroalkyl group include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.); Fluorard FC-93, FC-95, FC-98, FC- 129 (manufactured by Sumitomo 3M); Unidyne DS-101, DS-102 (manufactured by Daikin Industries); Megafac F-110, F-120, F-113, F-191, F-812, F-833 (large) Nippon Ink Chemical Co., Ltd.); Xtop EF-102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products); Neos) and the like.

  Examples of the cationic surfactant include amine salt type surfactants and quaternary ammonium salt type cationic surfactants. Examples of the amine salt type surfactant include alkylamine salts, aminoalcohol fatty acid derivatives, polyamine fatty acid derivatives, imidazolines, and the like. Examples of the quaternary ammonium salt type cationic surfactant include alkyltrimethylammonium salt, dialkyldimethylammonium salt, alkyldimethylbenzylammonium salt, pyridinium salt, alkylisoquinolinium salt, benzethonium chloride and the like. . Among the cationic surfactants, aliphatic quaternary ammonium such as aliphatic primary, secondary or tertiary amine acids having a fluoroalkyl group, perfluoroalkyl (6 to 10 carbon atoms) sulfonamidopropyltrimethylammonium salt, etc. Salts, benzalkonium salts, benzethonium chloride, pyridinium salts, imidazolinium salts, and the like. Commercially available products of the cationic surfactant include, for example, Surflon S-121 (manufactured by Asahi Glass Co., Ltd.); Florard FC-135 (manufactured by Sumitomo 3M Co.); Unidyne DS-202 (manufactured by Daikin Industries Ltd.), MegaFuck F-150 F-824 (manufactured by Dainippon Ink & Chemicals, Inc.); Xtop EF-132 (manufactured by Tochem Products);

Examples of the nonionic surfactant include fatty acid amide derivatives and polyhydric alcohol derivatives.
Examples of the amphoteric surfactant include alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine, N-alkyl-N, N-dimethylammonium betaine and the like.

Examples of the poorly water-soluble inorganic compound dispersant include tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, and hydroxyapatite.
Examples of the polymeric protective colloid include acids, (meth) acrylic monomers containing a hydroxyl group, vinyl alcohol or ethers of vinyl alcohol, esters of vinyl alcohol and a compound containing a carboxyl group, amides Examples thereof include homopolymers or copolymers such as compounds or their methylol compounds, chlorides, those having a nitrogen atom or a heterocyclic ring thereof, polyoxyethylenes, and celluloses.
Examples of the acids include acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid, maleic anhydride, and the like. Examples of the (meth) acrylic monomer containing a hydroxyl group include β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, and γ-acrylate. -Hydroxypropyl, γ-hydroxypropyl methacrylate, 3-chloro-2-hydroxypropyl acrylate, 3-chloro-2-hydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate Glycerin monomethacrylate, N-methylol acrylamide, N-methylol methacrylamide and the like. Examples of the vinyl alcohol or ethers with vinyl alcohol include vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, and the like. Examples of the esters of vinyl alcohol and a compound containing a carboxyl group include vinyl acetate, vinyl propionate, and vinyl butyrate. Examples of the amide compound or these methylol compounds include acrylamide, methacrylamide, diacetone acrylamide acid, or these methylol compounds. Examples of the chlorides include acrylic acid chloride and methacrylic acid chloride. Examples of the homopolymer or copolymer such as those having a nitrogen atom or a heterocyclic ring thereof include vinyl pyridine, vinyl pyrrolidone, vinyl imidazole, and ethylene imine. Examples of the polyoxyethylene are polyoxyethylene, polyoxypropylene, polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonylphenyl ether, polyoxyethylene Examples thereof include oxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, and polyoxyethylene nonyl phenyl ester. Examples of the celluloses include methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose.

In the preparation of the dispersion, a dispersion stabilizer can be used as necessary. Examples of the dispersion stabilizer include acids that are soluble in acids and alkalis such as calcium phosphate salts.
When the dispersion stabilizer is used, the calcium phosphate salt can be removed from the fine particles by a method of dissolving the calcium phosphate salt with an acid such as hydrochloric acid and then washing with water or a method of decomposing with an enzyme.

  In the preparation of the dispersion, a catalyst for the extension reaction or the crosslinking reaction can be used. Examples of the catalyst include dibutyltin laurate and dioctyltin laurate.

Furthermore, in order to lower the viscosity of the toner composition, a solvent in which the urea-modified polyester (i) or the prepolymer (A) is soluble can be used. The use of a solvent is preferable in that the particle size distribution becomes sharp. The solvent is preferably volatile from the viewpoint of easy removal.
Examples of the solvent include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, Examples thereof include methyl ethyl ketone and methyl isobutyl ketone. These may be used individually by 1 type and may use 2 or more types together. Among these, aromatic solvents such as toluene and xylene; halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform and carbon tetrachloride are preferable, and aromatic solvents such as toluene and xylene are more preferable.
0-300 mass parts is preferable, as for the usage-amount of the solvent with respect to 100 mass parts of said prepolymers (A), 0-100 mass parts is more preferable, and 25-70 mass parts is still more preferable. When a solvent is used, it is removed by heating under normal pressure or reduced pressure after the elongation and / or crosslinking reaction.

  The elongation and / or crosslinking reaction time is selected depending on the reactivity of the isocyanate group structure of the prepolymer (A) and the amines (B), but is usually preferably 10 minutes to 40 hours, and preferably 2 to 24 hours. More preferred. The reaction temperature is preferably 0 to 150 ° C, more preferably 40 to 98 ° C. Furthermore, a known catalyst can be used as necessary. Specific examples include dibutyltin laurate and dioctyltin laurate.

  In order to remove the organic solvent from the obtained emulsified dispersion, a method in which the temperature of the entire system is gradually raised to completely evaporate and remove the organic solvent in the droplets can be employed. It is also possible to spray the emulsified dispersion in a dry atmosphere to completely remove the water-insoluble organic solvent in the droplets to form toner fine particles, and also remove the aqueous dispersant by evaporating it. is there. As a dry atmosphere in which the emulsified dispersion is sprayed, a gas obtained by heating air, nitrogen, carbon dioxide gas, combustion gas, or the like, in particular, various air currents heated to a temperature equal to or higher than the boiling point of the highest boiling solvent used is generally used. Sufficient quality can be obtained with a short treatment such as spray dryer, belt dryer or rotary kiln.

When the particle size distribution at the time of emulsification dispersion is wide and washing and drying processes are performed while maintaining the particle size distribution, the particle size distribution can be adjusted by classifying into a desired particle size distribution.
In the classification operation, the fine particle portion can be removed in the liquid by a cyclone, a decanter, centrifugation, or the like. Although classification operation may be performed after obtaining as powder after drying, it is preferable in terms of efficiency to be performed in a liquid. The unnecessary fine particles or coarse particles obtained can be returned to the kneading step and used for the formation of particles. At that time, unnecessary fine particles or coarse particles may be wet.
The dispersant used is preferably removed from the obtained dispersion as much as possible, but it is preferable to carry out it simultaneously with the classification operation described above.

  By mixing the resulting dried toner powder with dissimilar particles such as release agent fine particles, charge control fine particles, fluidizing agent fine particles, and colorant fine particles, or by giving mechanical impact force to the mixed powder By immobilizing and fusing on the surface, it is possible to prevent detachment of the foreign particles from the surface of the resulting composite particle.

  As specific means, (1) a method of applying an impact force to the mixture by blades rotating at high speed, (2) the mixture is injected into a high-speed air stream, accelerated, and particles or composite particles are mixed with an appropriate collision plate. There is a method of making it collide. As equipment, Ong mill (manufactured by Hosokawa Micron Corporation), I-type mill (manufactured by Nippon Pneumatic Co., Ltd.), with reduced pulverization air pressure, hybridization system (manufactured by Nara Machinery Co., Ltd.), kryptron system ( Kawasaki Heavy Industries, Ltd.) and automatic mortar.

  As the colorant used in the toner, pigments and dyes conventionally used as toner colorants can be used. Specifically, carbon black, lamp black, iron black, ultramarine, nigrosine dye, Aniline blue, phthalocyanine blue, phthalocyanine green, Hansa yellow G, rhodamine 6C lake, calco oil blue, chrome yellow, quinacridone red, benzidine yellow, rose bengal and the like can be used alone or in combination.

  Further, if necessary, in order to give the toner particles magnetic properties, for example, iron oxides such as ferrite, magnetite and maghemite; metals such as iron, cobalt and nickel, or alloys of these with other metals, etc. The magnetic component may be contained alone or in combination in the toner particles. These components can also be used as a colorant component.

  Further, the number average particle diameter of the colorant in the toner used in the present invention is preferably 0.5 μm or less, more preferably 0.4 μm or less, and further preferably 0.3 μm or less. When the number average particle diameter exceeds 0.5 μm, the dispersibility of the pigment does not reach a sufficient level, and preferable transparency may not be obtained. On the other hand, the colorant having a fine particle diameter of less than 0.1 μm is sufficiently smaller than a half wavelength of visible light, and thus is considered not to adversely affect the light reflection and absorption characteristics. Therefore, the colorant particles having a number average particle size of less than 0.1 μm contribute to good color reproducibility and transparency of the OHP sheet having a fixed image. On the other hand, when there are many colorants having a particle size larger than 0.5 μm, the transmission of incident light is hindered or scattered, and the brightness of the projected image of the OHP sheet is reduced. There is a tendency to decrease the color. Further, when a large amount of colorant having a particle size larger than 0.5 μm is present, the colorant is detached from the surface of the toner particles, which may cause various problems such as fogging, drum contamination, and poor cleaning. The colorant having a particle size larger than 0.7 μm is preferably 10% by number or less, more preferably 5% by number or less of the total colorant.

Further, by mixing the colorant together with part or all of the binder resin in advance after adding a wetting liquid, the binder resin and the colorant are initially sufficiently attached, In the subsequent toner production process, the colorant is dispersed more effectively in the toner particles, the dispersed particle diameter of the colorant is reduced, and better transparency can be obtained.
As the binder resin used for kneading in advance, the resins exemplified as the binder resin for toner can be used as they are, but are not limited thereto.

  As a specific method for kneading the mixture of the binder resin and the colorant with the wetting liquid in advance, for example, the binder resin, the colorant and the wetting liquid are obtained after mixing with a blender such as a Henschel mixer. The obtained mixture is kneaded at a temperature lower than the melting temperature of the binder resin by a kneader such as a two-roll or three-roll to obtain a sample.

Further, as the wetting liquid, a general one can be used in consideration of the solubility of the binder resin and the paintability with the colorant, but an organic solvent such as acetone, toluene, butanone, and water are used as the colorant. It is preferable from the viewpoint of dispersibility. Among these, the use of water is particularly preferable from the viewpoint of environmental considerations and maintaining the dispersion stability of the colorant in the subsequent toner production process.
According to this manufacturing method, not only the particle diameter of the colorant particles contained in the obtained toner is reduced, but also the uniformity of the dispersion state of the particles is increased, so that the color reproducibility of the projected image by OHP is further improved. Get better.

The toner preferably contains a release agent together with the binder resin and the colorant.
The release agent is not particularly limited and may be appropriately selected from known ones according to the purpose. For example, polyolefin wax (polyethylene wax, polypropylene wax, etc.); long chain hydrocarbon (paraffin wax) And waxes containing carbonyl groups. Among these, a carbonyl group-containing wax is particularly preferable.
Examples of the carbonyl group-containing wax include polyalkanoic acid esters (carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1 , 18-octadecanediol distearate, etc.); polyalkanol esters (tristearyl trimellitic acid, distearyl maleate, etc.); polyalkanoic acid amides (ethylenediamine dibehenyl amide, etc.); polyalkylamides (trimellitic acid tristearyl amide) Etc.); dialkyl ketones (distearyl ketone, etc.) and the like. Among these, polyalkanoic acid esters are particularly preferable.

40-160 degreeC is preferable, as for melting | fusing point of the said mold release agent, 50-120 degreeC is more preferable, and 60-90 degreeC is still more preferable. When the melting point is less than 40 ° C., the heat resistant storage stability may be adversely affected.
The melt viscosity of the release agent is preferably 5 to 1000 cps, more preferably 10 to 100 cps at a temperature 20 ° C. higher than the melting point. When the melt viscosity exceeds 1000 cps, the effect of improving hot offset resistance and low-temperature fixability may be poor.
The content of the release agent in the toner is preferably 0 to 40% by mass, and more preferably 3 to 30% by mass.

Further, in order to accelerate the toner charge amount and its rise, a charge control agent may be contained in the toner as necessary. Since a color change occurs when a colored material is used as the charge control agent, a colorless or nearly white material is preferable.
The charge control agent is not particularly limited and may be appropriately selected from known ones according to the purpose. For example, triphenylmethane dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, Examples include quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, phosphorus simple substances or compounds, tungsten simple substances or compounds, fluorine-based activators, salicylic acid metal salts, and metal salts of salicylic acid derivatives.
As the charge control agent, a commercially available product can be used. Examples of the commercially available product include quaternary ammonium salt Bontron P-51, oxynaphthoic acid metal complex E-82, and salicylic acid metal complex. E-84, E-89 of a phenol-based condensate (both manufactured by Orient Chemical Industries); TP-302, TP-415 of a quaternary ammonium salt molybdenum complex (both manufactured by Hodogaya Chemical Co., Ltd.); Quaternary ammonium salt copy charge PSY VP2038, triphenylmethane derivative copy blue PR, quaternary ammonium salt copy charge NEG VP2036, copy charge NX VP434 (both manufactured by Hoechst); LRA-901, boron complex LR-147 (all manufactured by Nippon Carlit Co., Ltd.), quinacridone, azo face , Sulfonate group, carboxyl group, and polymer compounds having a functional group such as a quaternary ammonium salt.

  The amount of the charge control agent added varies depending on the type of the binder resin, the presence / absence of the additive, the toner production method including the dispersion method, and the like, and cannot be uniquely defined, but with respect to 100 parts by mass of the binder resin. 0.1-10 mass parts is preferable and 0.2-5 mass parts is more preferable. When the addition amount exceeds 10 parts by mass, the chargeability of the toner is too high, the effect of the charge control agent is reduced, the electrostatic attraction force with the developing roller is increased, the flowability of the developer is reduced, and the image The concentration may decrease. These charge control agents can be melted and kneaded together with a masterbatch and resin and then dissolved and dispersed, or they can be added directly when dissolved and dispersed in an organic solvent, or fixed after the toner particles are prepared on the toner surface. You may let them.

Further, when the toner composition is dispersed in the aqueous medium during the toner production process, resin fine particles mainly for stabilizing the dispersion may be added.
The resin fine particles may be any resin as long as it can form an aqueous dispersion, and may be a thermoplastic resin or a thermosetting resin. For example, vinyl resins, polyurethane resins, epoxy resins, polyester resins , Polyamide resin, polyimide resin, silicon resin, phenol resin, melamine resin, urea resin, aniline resin, ionomer resin, polycarbonate resin and the like. These may be used individually by 1 type and may use 2 or more types together. Among these, a vinyl resin, a polyurethane resin, an epoxy resin, a polyester resin, or a combination thereof is preferable because an aqueous dispersion of fine spherical resin particles can be easily obtained.
As the vinyl resin, a polymer obtained by homopolymerization or copolymerization of a vinyl monomer is used. For example, a styrene- (meth) acrylate resin, a styrene-butadiene copolymer, a (meth) acrylic acid-acrylate ester. Examples thereof include a polymer, a styrene-acrylonitrile copolymer, a styrene-maleic anhydride copolymer, and a styrene- (meth) acrylic acid copolymer.

As an external additive for assisting the fluidity, developability and chargeability of the toner particles, inorganic fine particles are suitable.
Examples of the inorganic fine particles include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, and diatomaceous earth. , Chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, silicon nitride and the like.
The primary particle diameter of the inorganic fine particles is preferably 5 nm to 2 μm, and more preferably 5 nm to 500 nm. The specific surface area of the inorganic fine particles by BET method is preferably 20 to 500 m <2> / g. The addition amount of the inorganic fine particles in the toner is preferably 0.01 to 5% by mass, and more preferably 0.01 to 2.0% by mass.

  Other polymer fine particles such as polystyrene, methacrylic acid ester and acrylic acid ester copolymer obtained by soap-free emulsion polymerization, suspension polymerization and dispersion polymerization, polycondensation system such as silicone, benzoguanamine and nylon, thermosetting resin And polymer particles.

  A fluidizing agent can also be added to the toner. The fluidizing agent performs surface treatment to increase hydrophobicity, and can prevent deterioration of flow characteristics and charging characteristics even under high humidity. Examples of the fluidizing agent include a silane coupling agent, a silylating agent, a silane coupling agent having a fluorinated alkyl group, an organic titanate coupling agent, an aluminum coupling agent, silicone oil, and modified silicone oil. Can be mentioned.

  Examples of the cleaning property improver for removing the developer after transfer remaining on the photosensitive member or the intermediate transfer member include fatty acid metal salts such as zinc stearate, calcium stearate and stearic acid; polymethyl methacrylate fine particles, polystyrene Examples thereof include polymer fine particles produced by soap-free emulsion polymerization of fine particles and the like. The polymer fine particles preferably have a relatively narrow particle size distribution and a volume average particle size of 0.01 to 1 μm.

  By using such a toner, as described above, it is possible to form a high-quality toner image having excellent development stability.

  Further, the image forming apparatus of the present invention can be applied not only to the combined use with the above-described polymerization method toner suitable for obtaining a high quality image, but also to an irregular shaped toner by a pulverization method, Even in this case, the life of the apparatus can be greatly extended. As a material constituting such a pulverized toner, those usually used as an electrophotographic toner can be applied without particular limitation.

  As the binder resin used in the pulverized toner, for example, styrene such as polystyrene, poly p-chlorostyrene, polyvinyltoluene, or the like, or a substituted polymer thereof; styrene / p-chlorostyrene copolymer, styrene / propylene Copolymer, styrene / vinyl toluene copolymer, styrene / vinyl naphthalene copolymer, styrene / methyl acrylate copolymer, styrene / ethyl acrylate copolymer, styrene / butyl acrylate copolymer, styrene / acrylic Octyl acid copolymer, styrene / methyl methacrylate copolymer, styrene / ethyl methacrylate copolymer, styrene / butyl methacrylate copolymer, styrene / α-chloromethyl methacrylate copolymer, styrene / acrylonitrile copolymer Styrene / vinyl methyl ketone copolymer, Styrene copolymers such as tylene / butadiene copolymers, styrene / isoprene copolymers, styrene / maleic acid copolymers; polymethyl acrylate, polybutyl acrylate, polymethyl methacrylate, polybutyl methacrylate, etc. Acrylic ester-based homopolymers or copolymers thereof; polyvinyl derivatives such as polyvinyl chloride and polyvinyl acetate; polyester-based polymers, polyurethane-based polymers, polyamide-based polymers, polyimide-based polymers, polyol-based polymers, Examples thereof include epoxy polymers, terpene polymers, aliphatic or alicyclic hydrocarbon resins, and aromatic petroleum resins. These may be used individually by 1 type and may use 2 or more types together. Among these, a styrene-acrylic copolymer resin, a polyester resin, and a polyol resin are preferable from the viewpoint of electrical characteristics, cost, and the like, and further, polyester resins and polyol resins are preferable as those having good fixing characteristics. Particularly preferred.

  In the pulverized toner, together with these resin components, the colorant component, wax component, charge control component and the like as described above are premixed as necessary, and then kneaded at a temperature close to the melting temperature of the resin component, and then cooled. Thereafter, a toner may be prepared through a pulverizing and classifying step, and the external additive component may be appropriately added and mixed as necessary.

  The developing device (developing device) may be of a dry developing type, a wet developing type, a single color developing unit, or a multicolor developing unit. For example, a toner having a stirrer that frictionally stirs and charges the toner or the developer, and a rotatable magnet roller is preferable.

In the developing device, for example, the toner and the carrier are mixed and stirred, and the toner is charged by friction at that time, and held on the surface of the rotating magnet roller in a raised state, thereby forming a magnetic brush. . Since the magnet roller is disposed in the vicinity of the image carrier (photosensitive member), a part of the toner constituting the magnetic brush formed on the surface of the magnet roller is caused by the electric attractive force. It moves to the surface of the image carrier (photoreceptor). As a result, the electrostatic latent image is developed with the toner, and a visible image is formed with the toner on the surface of the image carrier (photoconductor).
The developer accommodated in the developing device is a developer containing the toner, but the developer may be a one-component developer or a two-component developer.

<Transfer process and transfer means>
The transfer step is a step of transferring the visible image to a recording medium directly or via an intermediate transfer member. After the primary transfer of the visible image onto the intermediate transfer member using the intermediate transfer member, the transfer step is performed. A mode in which a visible image is secondarily transferred onto the recording medium is preferable. A second or more, preferably full color toner is used as the toner, and a visible image is transferred onto an intermediate transfer member to form a composite transfer image. An embodiment including a primary transfer step and a secondary transfer step of transferring the composite transfer image onto a recording medium is more preferable.
The transfer can be performed, for example, by charging the image carrier (photosensitive member) with the transfer charger using the visible image, and can be performed by the transfer unit. The transfer means includes a primary transfer means for transferring a visible image onto an intermediate transfer member to form a composite transfer image, and a secondary transfer means for transferring the composite transfer image onto a recording medium. Embodiments are preferred.
The intermediate transfer member is not particularly limited and may be appropriately selected from known transfer members according to the purpose. For example, an intermediate transfer belt is preferably used.

  The image carrier is used when performing image formation by a so-called intermediate transfer method, in which a toner image formed on a photosensitive member is primarily transferred to perform color superposition, and further transferred to a recording medium. It may be a transfer body.

-Intermediate transfer member-
As the intermediate transfer member, a material exhibiting conductivity of a volume resistance of 1.0 × 10 ^{5 to} 1.0 × 10 ¹¹ Ω · cm is preferable. When the volume resistance is less than 1.0 × 10 ⁵ Ω · cm, so-called transfer dust is generated in which the toner image is disturbed due to discharge when the toner image is transferred from the photosensitive member to the intermediate transfer member. If it exceeds 1.0 × 10 ¹¹ Ω · cm, the counter charge of the toner image remains on the intermediate transfer member after the toner image is transferred from the intermediate transfer member to a recording medium such as paper. May appear as an afterimage on other images.

As the intermediate transfer member, for example, a metal oxide such as tin oxide or indium oxide, a conductive particle such as carbon black, or a conductive polymer, alone or in combination, kneaded with a thermoplastic resin, and then an extrusion molded belt A cylindrical or cylindrical plastic can be used. In addition to this, the above-mentioned conductive particles and conductive polymer are added to a resin solution containing a thermally crosslinkable monomer or oligomer, if necessary, and subjected to centrifugal molding while heating to obtain an intermediate transfer member on an endless belt. You can also.
When the surface layer is provided on the intermediate transfer member, among the surface layer materials used for the surface layer of the photoreceptor described above, the composition excluding the charge transport material is appropriately adjusted in combination with a conductive substance, Can be used.

The transfer unit (the primary transfer unit and the secondary transfer unit) includes at least a transfer unit that peels and charges the visible image formed on the image carrier (photoconductor) to the recording medium side. It is preferable to have. There may be one transfer means or two or more transfer means. Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.
The recording medium is not particularly limited, and can be appropriately selected from known recording media (standard recording paper, non-standard recording paper, cardboard, postcard, OHP sheet, etc.).

<Protective layer forming step and protective layer forming means>
The protective layer forming step is a step of forming a protective layer by applying the image carrier protective agent of the present invention to the surface of the image carrier after transfer.
As the protective layer forming means, the protective layer forming apparatus 2 of the present invention described above can be used.

<Fixing process and fixing means>
The fixing step is a step of fixing the visible image transferred to the recording medium using the fixing unit, and may be performed each time the toner of each color is transferred to the recording medium, or may be applied to the toner of each color. On the other hand, it may be carried out simultaneously at the same time in a state of being laminated.
The fixing unit is not particularly limited and may be appropriately selected depending on the intended purpose. However, a known heating / pressurizing unit is preferable. Examples of the heating / pressurizing means include a combination of a heating roller and a pressure roller, a combination of a heating roller, a pressure roller, and an endless belt.
The heating in the heating / pressurizing means is usually preferably 80 ° C to 200 ° C. As a heating method, various heating methods such as heater heating such as an electric heater, a halogen heater, and a carbon heater, electromagnetic induction heating using electromagnetic induction, and heating using a heating element such as a thermal head can be used.
In the present invention, for example, a known optical fixing device may be used together with or in place of the fixing step and the fixing unit depending on the purpose.

The neutralization step is a step of performing neutralization by applying a neutralization bias to the image carrier, and can be suitably performed by a neutralization unit.
The neutralization means is not particularly limited, and may be appropriately selected from known neutralizers as long as it can apply a neutralization bias to the image carrier. For example, a neutralization lamp or the like is preferable. It is done.

The cleaning step is a step of removing the electrophotographic toner remaining on the image carrier and can be suitably performed by a cleaning unit.
The cleaning means is preferably provided downstream of the transfer means in the moving direction (rotation direction) of the surface of the image carrier and upstream of the protective layer forming apparatus.
The cleaning means is not particularly limited, and may be selected from known cleaners as long as the electrophotographic toner remaining on the image carrier can be removed. For example, a magnetic brush cleaner, Suitable examples include electrostatic brush cleaners, magnetic roller cleaners, blade cleaners, brush cleaners, web cleaners, and the like.

The recycling step is a step of recycling the toner removed by the cleaning step to the developing unit, and can be suitably performed by the recycling unit.
The recycling means is not particularly limited, and known transport means (transport means using a coil, a screw, etc., means for transporting by mixing with air using a powder pump or an air pump, electrostatic transport means), etc. Can be mentioned.

The control means is a process for controlling the respective steps, and can be suitably performed by the control means.
The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as a sequencer and a computer.

<Configuration example of image forming apparatus>
Here, FIG. 3 is a schematic sectional view showing an example of the image forming apparatus 100 including the protective layer forming apparatus of the present invention.
The image forming apparatus 100 includes an image forming apparatus main body (printer unit) 110 that performs image formation, a document reading unit (scanner unit) 120 installed on the upper part of the main unit 110, and an automatic document supply unit installed thereon. A paper device (ADF) 130 and a paper feed unit 200 installed at the lower part of the image forming apparatus main body 110 are provided, and have a function of a copying machine. The image forming apparatus 100 has a communication function with an external device, and can be used as a printer or a scanner by connecting to a personal computer or the like outside the device via a LAN. Further, it can be used as a facsimile by connecting to a telephone line or an optical line.

  In the image forming apparatus main body 110, four image forming units (image forming stations) 10 having the same configuration and different toner colors of the developing device 5 are arranged in parallel, and the four image forming units 10 have different toner colors. An image (for example, an image of yellow (Y), magenta (M), cyan (C), and black (K)) is formed, and a toner image of each color is superimposed on a transfer medium or an intermediate transfer medium and transferred to obtain multiple colors or A full color image can be formed. In the example of FIG. 3, the four image forming units 10 are juxtaposed along a belt-shaped transfer medium (hereinafter referred to as an intermediate transfer member) 7 stretched around a plurality of rollers. The toner images of the respective colors formed by the forming unit are sequentially transferred to the intermediate transfer member 7 in order, and then transferred to a sheet-like recording medium such as paper by the secondary transfer device 12.

  The image forming unit 10 for each color has the same configuration as that shown in FIG. 2, and a protective layer forming device 2, a charging device 3, a static device are formed around an image carrier (for example, a photosensitive drum) 1 (1Y, 1M, 1C, 1K). An exposure unit such as a laser beam from the electrostatic latent image forming device 8, a developing device 5, a primary transfer device 6, and a cleaning device 4 are arranged. Similarly to FIG. 2, the image forming unit 10 of each color includes a process cartridge 11 in which a protective layer forming device 2, a charging device 3, a developing device 5, and a cleaning device 4 are provided in a cartridge together with the photoreceptor 1. Used. The process cartridge 11 is detachably attached to the image forming apparatus main body 110.

Next, the operation of the image forming apparatus shown in FIG. 3 will be described. Here, a series of processes for image formation will be described using a negative-positive process. The operation of each image forming unit is the same.
Image carriers 1Y, 1M, 1C, and 1K typified by a photoreceptor (OPC) having an organic photoconductive layer are neutralized by a static elimination lamp (not shown) or the like, and uniformly negative by a charging device 3 having a charging member. Is charged.
When the image carrier is charged by the charging device, the image carrier 1Y, 1M, 1C, 1K is charged to a desired potential from a voltage application device (not shown) to a charging member (for example, a charging roller). A voltage of an appropriate magnitude suitable for the above or a charging voltage obtained by superimposing an AC voltage thereon is applied.
The charged image carriers 1Y, 1M, 1C, and 1K form a latent image with laser light irradiated by an electrostatic latent image forming apparatus 8 including exposure means such as a laser optical system (the absolute value of the exposure portion potential is The potential becomes lower than the absolute value of the non-exposed portion potential).
Laser light is emitted from a semiconductor laser, and the surfaces of the image carriers 1Y, 1M, 1C, and 1K are moved along the rotation axis direction of the image carrier (main scanning direction) by a polygonal polygon mirror that rotates at high speed. Scan).
The latent image formed in this way is developed with a developer made of toner particles or a mixture of toner particles and carrier particles supplied on the developing sleeve of the developing roller 51 which is a developer carrying member in the developing device 5. As a result, a visible image of the toner is formed.
At the time of developing the latent image, a voltage of an appropriate magnitude or a voltage between the exposed portion and the non-exposed portion of the image carrier 1Y, 1M, 1C, 1K is applied to the developing sleeve from a voltage application mechanism (not shown). A developing bias superimposed with an AC voltage is applied.

The toner images formed on the image carriers 1Y, 1M, 1C, and 1K corresponding to the respective colors by the operation as described above are primarily transferred onto the intermediate transfer body 7 by the primary transfer device 6 in order. On the other hand, in synchronization with the image forming operation and the primary transfer operation, the paper feed roller 202 and the separation roller are selected from the paper feed cassettes selected from the multi-stage paper feed cassettes 201a, 201b, 201c, and 201d of the paper feed unit 200. A sheet-like recording medium such as paper is fed by a paper feeding mechanism 203, and is conveyed to a secondary transfer unit via conveying rollers 204, 205, 206 and registration rollers 207. In the secondary transfer portion, the toner image on the intermediate transfer member 7 is secondarily transferred to the conveyed recording medium by a secondary transfer device (for example, a secondary transfer roller) 12. In the above transfer step, it is preferable that a potential having a polarity opposite to the charging polarity of the toner is applied to the primary transfer device 6 and the secondary transfer device 12 as a transfer bias.
After the secondary transfer described above, the recording medium is separated from the intermediate transfer member 7 to obtain a transfer image. Further, the toner particles remaining on the photoreceptor 1 after the primary transfer are collected into the toner collection chamber in the cleaning device 4 by the cleaning member 41 of the cleaning device 4. Further, the toner particles remaining on the intermediate transfer member 7 after the secondary transfer are collected into the toner collecting chamber in the belt cleaning device 9 by the cleaning member of the belt cleaning device 9.

  An image forming apparatus 100 shown in FIG. 3 is a so-called tandem type intermediate transfer type image forming apparatus in which a plurality of the above-described image forming units 10 are arranged along the intermediate transfer body 7. A plurality of toner images with different colors sequentially formed on the respective photoreceptors 1Y, 1M, 1C, and 1K are once transferred onto the intermediate transfer body 7 and then transferred to a recording medium such as paper at once. To do. Then, the recording medium onto which the toner image has been transferred is sent to the fixing device 14 by the transport device 13 and the toner is fixed by heating, pressing, or the like. The recording medium after fixing is discharged to a discharge tray 17 by a transport device 15 and a discharge roller 16. The image forming apparatus 100 also has a double-sided printing function. During double-sided printing, the conveyance path downstream of the fixing device 14 is switched, and a recording medium on which a single-sided image is fixed is transferred through the double-sided conveyance apparatus 210. The paper is reversed, and is fed again to the secondary transfer unit by the transport roller 206 and the registration roller 207, and the image is transferred to the back side. The recording medium after transfer is conveyed to the fixing device 14 in the same manner as described above to fix the image, and the recording medium after fixing is discharged to a discharge tray 17.

  In the above configuration, the intermediate transfer member can be used without using an intermediate transfer member, and a tandem type direct transfer method image forming apparatus can be used. In the case of this direct transfer method, a recording medium is supported instead of the intermediate transfer member. Using a transfer belt or the like that transports, a plurality of toner images of different colors, which are sequentially created on each photoreceptor 1 (1Y, 1M, 1C, 1K) by each image forming unit 10, are directly transported by the transfer belt. Alternatively, the toner may be fixed to the recording medium after being sequentially transferred to the fixing device 14 by heating and pressurizing.

In the image forming apparatus as described above, the charging device 3 is preferably a charging device in which a charging member such as a charging roller is disposed in contact with or in close proximity to the surface of the image carrier. Compared with a so-called corotron or socorotron using a corona discharger, the amount of ozone generated during charging can be greatly suppressed.
However, in the charging device 3 that charges such a charging member in contact with or close to the surface of the image carrier, the discharge is performed in the region near the surface of the image carrier as described above. Tend to be stressful. However, protection using the image carrier protecting agent 21 containing the hydrophobic organic compound (A), the inorganic lubricant (B), the inorganic fine particles (C), and the surface-treated inorganic lubricant (D) of the present invention. By using the layer forming apparatus 2, the image carrier 1 can be maintained for a long time without deteriorating, so that it is possible to greatly suppress image variations over time and image variations due to the use environment, and to achieve stable image quality. Securement is possible.

  As described above, the image forming apparatus of the present invention has an excellent tolerance for fluctuations in the surface state of the image carrier, and has a configuration in which fluctuations in charging performance to the image carrier are highly suppressed. By using in combination with the toner having the structure, an extremely high quality image can be stably formed over a long period of time.

  Hereinafter, in the image forming apparatus according to the present invention, the hydrophobic organic compound (A), the inorganic lubricant (B), the inorganic fine particles (C), and the surface-treated inorganic lubricant (D) are added to the image carrier. The specific Example at the time of apply | coating the protective agent containing is shown, and a comparative example.

  An image forming apparatus (in this case, a modified Ricoh copier imagio MP C3000 is used) having a process cartridge 11 having a protective layer forming apparatus 2 as shown in FIG. A protective agent supply mechanism corresponding to the protective agent supply member 22 of FIG. 1 is installed upstream of the protective layer forming mechanism 24 serving also as a cleaning member, and a hydrophobic organic compound (A) is attached to the image carrier (photosensitive member) 1. A protective agent containing an inorganic lubricant (B), inorganic fine particles (C), and a surface-treated inorganic lubricant (D) was applied. Tables 1 and 2 below list the examples and comparative examples.

Here, in Examples 1 to 3, an image carrier protecting agent containing a hydrophobic organic compound (A), an inorganic lubricant (B), inorganic fine particles (C), and a surface-treated inorganic lubricant (D). In Comparative Example 1, only one type of hydrophobic organic compound (A) was used as the image carrier protecting agent.
In Comparative Example 2, two kinds of hydrophobic organic compound (A) and inorganic lubricant (B) were used as the image carrier protecting agent.
In Comparative Example 3, two kinds of hydrophobic organic compound (A) and inorganic fine particles (C) were used as the image carrier protecting agent.
In Comparative Example 4, two types of an image carrier protecting agent were used: a hydrophobic organic compound (A) and a surface-treated inorganic lubricant (D).
In Comparative Example 5, three types of hydrophobic organic compound (A), inorganic lubricant (B), and inorganic fine particles (C) were used as the image carrier protecting agent.
In Comparative Example 6, as the image carrier protecting agent, three types of hydrophobic organic compound (A), inorganic fine particles (C), and surface-treated inorganic lubricant (D) were used.
As an image carrier protecting agent in Comparative Examples and Examples, zinc stearate, one of fatty acid metal salts, was used for the hydrophobic organic compound (A). And boron nitride was used for the inorganic lubricant (B). For the inorganic fine particles (C), alumina particles having an average particle size of 0.3 μm were used. In the surface-treated inorganic lubricant (D), in Comparative Examples 4 and 6 and Example 1, talc using fluorinated silane was used as the surface treatment agent, and in Example 2, silicone was used as the treatment agent. In Example 3, talc, kaolin using silicone as a treating agent, was used.
In the above test conditions, zinc stearate used was Zinc Stearate GF200 manufactured by Nippon Oil & Fats, and alumina particles manufactured by Sumitomo Chemical were used. Boron nitride was manufactured by Mizushima Alloy. Talc and kaolin were manufactured by Miyoshi Kasei Co., Ltd.

An image output test was performed in which 100,000 copies of originals each having an A4 size and an image area ratio of 6% were continuously output with the above-described protective agent. Thereafter, the blade edge was observed with a laser microscope to observe the blade wear state. The laser microscope used was VK9000 manufactured by Keyence Corporation, and the magnification of the objective lens was 50 times. Thereafter, the filming on the photosensitive member, the state of adhered matter, the contamination state of the charging member, and the obtained output image were visually evaluated.
As the evaluation in Table 2, the charging member contamination state (roller contamination), blade wear, and photoconductor filming were evaluated according to the following criteria.

(Roller dirt evaluation)
A: No contamination at all.
○: Almost no contamination.
Δ: Contaminated but acceptable.
X: Contaminated greatly.

(Evaluation of blade wear)
(Double-circle): It is not worn out at all.
○: Almost no wear.
Δ: Abraded but acceptable.
X: It is worn out greatly.

(Evaluation of photoconductor filming)
A: There is no filming at all.
○: Almost no filming.
Δ: Filming is in an allowable range.
X: Filming is large.

(Operational effect of the present invention)
The image carrier protecting agent of the present invention is considered to be able to prevent charging member contamination, image carrier filming, and blade wear for the following reasons.
An image carrier protecting agent is applied to an image carrier used for an electrophotographic image forming method or an image forming apparatus in order to protect the image carrier from charging and cleaning hazards. However, the fatty acid metal salt, which is a hydrophobic organic compound (A) that is generally used as a protective agent, loses its lubricity due to the effect of charging, and the toner or protective agent slips through the cleaning member. It flies and adheres to the member, causing charging member contamination.
Therefore, by adding the inorganic lubricant (B), it is possible to assist lubricity, prevent the toner and the protective agent from slipping through, and reduce the amount of the hydrophobic organic compound (A) flying to the charging member.
However, when only the inorganic lubricant (B) is added, it is difficult to remove from the surface of the image carrier due to high lubricity between the image carrier and the cleaning member, and filming on the image carrier is difficult. End up.
Further, the high lubricity promotes the polishing effect of the toner and its additives, and the cleaning member is greatly worn.

Therefore, in addition to the hydrophobic organic compound (A) and the inorganic lubricant (B), the inorganic lubricant (B) can be removed by the inorganic fine particles (C) by adding the inorganic fine particles (C). Become. Accordingly, filming does not occur on the image carrier.
Further, in addition to the hydrophobic organic compound (A), the inorganic lubricant (B), and the inorganic fine particles (C), the surface-treated inorganic lubricant (D) is added to increase the height between the image carrier and the cleaning member. It is possible to suppress excessive lubricity and prevent the cleaning member from being polished by the toner and its additive. This is considered because the surface-treated inorganic lubricant (D) has lower lubricity than the inorganic lubricant (B).
However, when only the hydrophobic organic compound (A) is used, when the inorganic lubricant (B) is added to the hydrophobic organic compound (A), and when the inorganic fine particles (C) are added to the hydrophobic organic compound (A). ) And when the inorganic lubricant (B) and the inorganic fine particles (C) are added to the hydrophobic organic compound (A), high lubricity is obtained. In addition, the lubricity does not deteriorate due to the influence of charging, and the toner and the hydrophobic organic compound (A) do not slip through the cleaning member and do not fly to the charging member, so that the charging member is not contaminated.

Here, as in Examples 1 to 3, on the surface of the image carrier, a hydrophobic organic compound (A), an inorganic lubricant (B), inorganic fine particles (C), and a surface-treated inorganic lubricant (D By applying or adhering the image bearing member protective agent containing), contamination of the charging member, blade wear, and filming (foreign matter / adhered matter) can be prevented.
On the other hand, when only the hydrophobic organic compound (A) is used as the image carrier protective agent as in Comparative Example 1, the lubricity is greatly reduced by the stress caused by charging, and the protective agent is used together with the toner slipping. As a result, the charging member is heavily contaminated.

In addition, when the hydrophobic organic compound (A) and the inorganic lubricant (B) are used as in Comparative Example 2, the lubricity between the image carrier and the cleaning member due to charging stress is greatly improved, and the toner Since there is no slip through and no protective agent slips out, the charging member is not contaminated.
However, the inorganic lubricant (B) adheres to the image carrier and filming occurs. Further, since the lubricity is too high, the cleaning member is polished by the toner particles and wear occurs.

Even when the hydrophobic organic compound (A) and the inorganic fine particles (C) are used as in Comparative Example 3, although the lubricity between the image carrier and the cleaning member is slightly improved by the charging stress, the toner slips through. At the same time, since the protective agent slips through, the charging member is contaminated.
Further, as in Comparative Example 4, when the image carrier protecting agent containing the hydrophobic organic compound (A) and the surface-treated inorganic lubricant (D) is used, the charging member is the same as in Comparative Example 3. Contamination occurs.

As in Comparative Example 5, when an image carrier protective agent containing a hydrophobic organic compound (A), an inorganic lubricant (B), and inorganic fine particles (C) was used, toner slipping and protective agent Since no slip-through occurs, the charging member is not contaminated. Even if the inorganic lubricant (B) adheres to the image bearing member, filming does not occur because the inorganic fine particles (C) polish it.
However, although the polishing of the cleaning member with toner particles is slightly improved,
Wear of the cleaning member occurs.
Further, as in Comparative Example 6, the image carrier protective agent containing the hydrophobic organic compound (A), the inorganic fine particles (C), and the surface-treated inorganic lubricant (D) has poor lubricity, and the toner slips. At the same time, since the protective agent slips through, the charging member is contaminated.

In addition to the hydrophobic organic compound (A), the inorganic lubricant (B), and the inorganic fine particles (C), the surface-treated inorganic lubricant (D) is added to the surface of the image carrier as in Examples 1 to 3. By doing so, it is possible to suppress excessive lubricity between the image carrier and the cleaning member, eliminate polishing of the cleaning member by the toner and its additive, and prevent the cleaning member from being worn.
Further, since a certain level of high lubricity is ensured, as described above, the lubricity does not deteriorate due to the effect of charging, and toner and protective agent do not slip through the cleaning member and do not fly to the charging member. It will not cause component contamination.
As a result, contamination of the charging member, filming (foreign matter / adhered matter), and blade wear can be prevented at the same time.

  In the present invention, the hydrophobic organic compound (A) is a substance having a lamellar crystal, and the hydrophobic organic compound (A) is a metal salt of a fatty acid. As shown in FIG. 3, by covering the surface of the image carrier relatively uniformly with a lubricant using zinc stearate, it is possible to provide good protection from electrical stress in the charging process. In addition, a substance having a lamellar crystal has a layered structure in which amphiphilic molecules are self-organized, and when a shearing force is applied, the crystal is broken and slips easily along the layer. Therefore, the lubricity is excellent. Among these, fatty acid metal salts, particularly zinc stearate, are used in many electrophotographic image forming apparatuses.

In the present invention, the inorganic lubricant (B) is a two-dimensional layer structure, and the inorganic lubricant (B) is talc, mica, boron nitride, kaolin, plate-like alumina, sericite, disulfide. It is characterized by containing at least one of molybdenum, tungsten disulfide, montmorillonite, calcium fluoride, and graphite. As in Examples 1 to 3, the inorganic lubricant of the two-dimensional layer structure is an image carrier. And the cleaning member are greatly improved, the toner does not slip through, and the protective agent does not slip through. Therefore, contamination of the charging member can be prevented.
Here, the two-dimensional layer structure refers to a substance having a layered structure bonded by a metal bond, a covalent bond or an ionic bond, and the layers are bonded only by van der Waals force.

  In the present invention, the inorganic fine particles (C) are one or more substances selected from the group consisting of silica, alumina, titania, zirconia, magnesia, ferrite and magnetite, but silica, alumina, Titania, zirconia, magnesia, ferrite, and magnetite can produce uniform particles with a small particle size at low cost, are excellent as an abrasive, and have an effect of preventing filming.

In the present invention, the inorganic lubricant of the surface-treated inorganic lubricant (D) is a two-dimensional layer structure, and the inorganic lubricant of the surface-treated inorganic lubricant (D) is talc, mica, nitriding Inorganic lubricant (D) characterized by containing at least one of boron, kaolin, plate-like alumina, sericite, molybdenum disulfide, tungsten disulfide, montmorillonite, calcium fluoride, graphite, and surface treatment The surface treatment is characterized by a surface treatment with a treating agent having a reactive substituent. This is because an inorganic lubricant of a two-dimensional layer structure showing high lubricity is treated with a reactive substituent. This is a treatment agent that has been chemically adsorbed or adhered to its surface.
This surface-treated inorganic lubricant (D) suppresses excessive lubricity between the image carrier and the cleaning member, and can prevent the cleaning member from being polished by the toner and its additive.

The image carrier protecting agent of the present invention exhibits a protective effect by adhering to the surface of the image carrier and forming a film, and thus is relatively easily plastically deformed. Therefore, when an attempt is made to form a protective layer by directly pressing the bulky image carrier protective agent component onto the surface of the image carrier, the supply is excessive and the protective layer formation efficiency is not good, and the protective layer is multi-layered. Since it may become a factor that impedes light transmission in an exposure process such as when forming an electrostatic latent image, the types of image carrier protecting agents that can be used are limited.
On the other hand, the protective layer forming apparatus of the present invention is configured as shown in FIG. 1 or 2, for example, and by passing a protective agent supply member 22 between the image carrier protective agent 21 and the image carrier 1, Even when a soft image carrier protective agent is used, the protective agent can be evenly supplied to the surface of the image carrier.
When the protective layer forming apparatus 2 is provided with a protective layer forming mechanism 24 that presses the image carrier protective agent 21 to form a film, the layer forming member 24a such as a blade may serve as a cleaning member, but more reliably. In order to form the protective layer, as shown in FIGS. 1 and 2, the residue on the image carrier as a main component is removed in advance by the cleaning member 41 of the cleaning means 4, and the residue becomes the protective layer. It is preferable not to mix in the inside.

  In the present invention, by the image forming method using the protective layer forming apparatus 2 having the image carrier protecting agent 21, excessive lubricity between the image carrier and the cleaning member is suppressed, and the toner and the addition thereof are added to the cleaning member. Polishing by the agent can be prevented. In addition, since a certain level of high lubricity is ensured, the lubricity does not deteriorate due to the effect of charging, and toner and protective agent do not slip through the cleaning member and do not fly to the charging member, thus causing contamination of the charging member. There is nothing wrong. As a result, contamination of the charging member, filming (foreign matter / adhered matter), and blade wear can be prevented at the same time.

In the present invention, as shown in FIGS. 1 to 3, an image forming apparatus is configured by using a protective layer forming apparatus 2 having an image carrier protecting agent 21. Can be used for a long time without replacement.
In particular, when the image carrier includes a thermosetting resin in at least the layer formed on the outermost surface, the image carrier is prevented from being deteriorated by an electrical stress, and the thermosetting property is prevented. The durability of the image bearing member including the resin against mechanical stress can be continuously expressed over a long period of time.
Further, in the charging device disposed in contact with or close to the surface of the image carrier, the electrical stress tends to be large because the discharge region exists in the very vicinity of the image carrier. If the image forming apparatus of the present invention in which is formed, the image carrier can be used without being exposed to electrical stress.
In addition, the surface of the image carrier can be made to have a very small change in surface state due to the effect of the protective layer formed, so that the quality of the cleaning changes sensitively to the state change of the image carrier. Even a toner having a large degree or a toner having a small average particle diameter can be stably cleaned over a long period of time.
Furthermore, since the water contact angle on the surface of the image carrier can be improved and the surface of the image carrier can be kept water repellent, moisture absorption on the surface of the image carrier can be prevented and image blur can be suppressed.

In the present invention, as shown in FIG. 2, the process cartridge 11 is configured using the protective layer forming apparatus 2 having the image carrier protecting agent 21, thereby setting the replacement interval of the process cartridges to be extremely long. Therefore, the running cost is reduced and the amount of waste can be greatly reduced.
In particular, when the image carrier includes a thermosetting resin in at least the layer formed on the outermost surface, the image carrier is prevented from being deteriorated by an electrical stress, and the thermosetting property is prevented. The durability of the image bearing member including the resin against mechanical stress can be continuously expressed over a long period of time.
Further, as described above, since the image carrier protecting component of the present invention does not substantially contain a metal component, the charging member disposed in contact or close to the charging member is not contaminated with a metal oxide or the like. The change with time of the charging device can be reduced.
For this reason, it becomes easy to reuse process cartridge components such as an image carrier and a charging member, and the amount of waste can be further reduced.

  In the present invention, as in the image forming apparatus shown in FIG. 3, one or more process cartridges 11 are juxtaposed in the image forming unit 10 so that a good quality monochromatic, multicolored, color image can be obtained for a long time. Therefore, an image forming apparatus that can be obtained stably can be realized.

It is a schematic principal part block diagram which shows the principal part structural example of the image forming part provided with the protective layer forming apparatus of this invention. It is a schematic sectional drawing for demonstrating the outline of the structural example of the process cartridge using the protective layer forming apparatus of this invention. It is a schematic block diagram which shows the structural example of the image forming apparatus which comprises the protective layer forming apparatus of this invention.

Explanation of symbols

1 (1Y, 1M, 1C, 1K): image carrier (photosensitive drum)
2: Protection layer forming device 3: Charging device (charging means)
4: Cleaning device (cleaning means)
5: Developing device (developing means)
6: Primary transfer device (transfer means)
7: Intermediate transfer member (or transfer medium)
8: Electrostatic latent image forming device 9: Belt cleaning device 10: Image forming unit 11: Process cartridge 12: Secondary transfer device 13: Conveying device 14: Fixing device 15: Conveying device 16: Paper ejection roller 17: Paper ejection tray 21: Image carrier protecting agent 22: Protecting agent supply member 22a: Brush-like member (brush)
22b: support 23: pressing force application mechanism 24: protective layer forming mechanism 24a: blade-like member (blade)
24b: pressing member 25: protective agent support member 41: cleaning member (cleaning blade)
42: cleaning pressing member 51: developing roller 52, 53: stirring and conveying screw 100: image forming apparatus 110: image forming apparatus main body (printer unit)
120: Document reading unit (scanner unit)
130: Automatic document feeder (ADF)
200: paper feed unit 201a to 201d: paper feed cassette 202: paper feed roller 203: separation roller 204, 205, 206: transport roller 207: registration roller 210: transport device for both sides L: exposure

Claims (10)

In an image carrier protecting agent used in an image forming method or an image forming apparatus having at least a step of applying or adhering an image carrier protecting agent to the surface of the image carrier having an image carrier,
The image bearing member protecting agent, a hydrophobic organic compound (A), the inorganic lubricant (B), and the inorganic fine particles (C), seen containing surface-treated inorganic lubricant (D), the hydrophobic organic compound (A) is a substance having a lamellar crystal, and the hydrophobic organic compound is made of zinc stearate which is a metal salt of a fatty acid, and the inorganic lubricant (B) is a two-dimensional layer structure. The inorganic lubricant (B) is made of boron nitride, the inorganic fine particles (C) are made of alumina particles, and the surface-treated inorganic lubricant (D) has a two-dimensional layer structure. An image carrier protecting agent , wherein the inorganic lubricant of the surface-treated inorganic lubricant (D) comprises talc or kaolin . In the image carrier protecting agent according to claim 1,
An image carrier protective agent, wherein the surface treatment of talc or kaolin, which is an inorganic lubricant of the surface-treated inorganic lubricant (D), is a surface treatment with a treatment agent having a reactive substituent . In a protective layer forming apparatus for applying or adhering an image carrier protective agent to the surface of an image carrier,
The protective layer forming apparatus, wherein the image carrier protective agent is the image carrier protective agent according to claim 1. In the protective layer formation apparatus of Claim 3,
The protective layer forming apparatus, wherein the image carrier protecting agent is supplied to the surface of the image carrier through a supply member. In the protective layer formation apparatus of Claim 3 or 4,
A protective layer forming apparatus comprising: a layer forming member that presses the image carrier protective agent supplied to the surface of the image carrier to form a film. At least an image carrier through which a toner image is carried; and
Transfer means for transferring the toner image on the image carrier to a transfer medium;
In the image forming method comprising a protective layer forming means for applying or adhering an image carrier protecting agent to the surface of the image carrier after the toner image is transferred to the transfer medium.
The image forming method according to claim 1, wherein the image carrier protecting agent is the image carrier protecting agent according to claim 1. At least an image carrier through which a toner image is carried; and
A transfer device for transferring the toner image on the image carrier to a transfer medium;
In the image forming apparatus provided with a protective layer forming device for applying or adhering an image carrier protecting agent to the surface of the image carrier after the toner image is transferred to the transfer medium,
The image forming apparatus according to claim 1, wherein the image carrier protecting agent is the image carrier protecting agent according to claim 1. The image forming apparatus according to claim 7.
The toner remaining on the surface of the image carrier on the downstream side of the transfer device in the moving direction of the surface of the image carrier and on the upstream side of the protective layer forming device is removed by rubbing against the surface of the image carrier. An image forming apparatus comprising a cleaning device that removes the toner. The image forming apparatus according to claim 7 or 8 , wherein
An image forming apparatus, wherein the image carrier includes a thermosetting resin in at least a layer formed on the outermost surface . At least an image carrier through which a toner image is carried; and
In a process cartridge integrally provided with a protective layer forming apparatus for applying or adhering an image carrier protective agent to the surface of the image carrier after the toner image is transferred to a transfer medium,
The process cartridge according to claim 1, wherein the image carrier protecting agent is the image carrier protecting agent according to claim 1.

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