JPH0651553A - Toner for developing electrostatic charge image and image forming mehtod - Google Patents

Abstract

PURPOSE:To provide a toner for developing an electrostatic charge image and an image forming method capable of preventing defective cleaning and the occurrence of image defects and capable of giving an image excellent in fine line reproducibility and highlight gradation. CONSTITUTION:In a toner for developing an electrostatic charge image contg. toner particles and additives, at least titanium oxide particles (A) having 0.01-0.2mum weight average particle diameter subjected to treatment for imparting hydrophobic property, org. resin particles (B) having 0.02-0.5mum weight average particle diameter and an inorg. compd. (C) having 0.5-2.5mum weight average particle diameter are used as the additives so as to satisfy (2:1)-(10:1) ratio of A:B and (2:1)-(5:1) ratio of A:C. The toner contains 15-40 number % toner particles having 2-5um particle diameter.

Description

Detailed Description of the Invention

[0001]

The present invention relates to an organic photoconductive material (O
A development image is formed with toner using a photoreceptor containing PC) (hereinafter referred to as “OPC photoreceptor”) as a latent image carrier, and the development image is transferred to a transfer material to obtain a visible image. The present invention relates to an image forming method in which the latent image bearing member is cleaned with a cleaning member and the latent image bearing member after cleaning is repeatedly used, and an electrostatic image developing toner suitable for the method.

[0002]

2. Description of the Related Art In recent years, many image forming apparatuses such as electrophotographic color copying machines and printers using an OPC photosensitive member as a latent image carrier have been manufactured. Usually, such an image forming apparatus forms a latent image on an OPC photoconductor by a normal electrophotographic process, develops the latent image by a developing device to form a developed (toner) image, and develops the developed image. Is transferred to a transfer material to obtain a visible image. On the other hand, the residual developed image on the latent image carrier is cleaned by a cleaning member, and the latent image carrier is repeatedly used.

As a cleaning means, a blade cleaning means having a structure in which a cleaning blade made of a rubber elastic material is brought into pressure contact with the latent image carrier because it is simple and small in size, and is very advantageous in terms of cost. Is widely used.

Generally, the OPC photoreceptor is a charge generation layer comprising a binder in which a charge generation material is dispersed on a conductive support,
The charge transporting material is composed of a charge transporting layer in which a charge transporting material is dispersed, and the charge transporting layer is laminated in this order. Dyes such as cyanine dyes are used, and as the charge transport material, carbazoles such as pyrene and isopropylcarbazole, hydrazones, pyrazolines, oxasonyl compounds, thiazole compounds, triarylmethane compounds, polyarylalkanes. Is used. As the binder, polyacrylate resin, polysulfone resin, polyamide resin, acrylic resin, acrylonitrile resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, phenol resin, epoxy resin, polyester resin, alkyd resin, polycarbonate, polyurethane or these Copolymer resins containing two or more of the repeating units of the resin, such as styrene-butadiene copolymer, styrene-acrylonitrile copolymer, and styrene-maleic acid copolymer are used.

According to the results of the research experiments conducted by the present inventors,
It was found that the coefficient of friction of the latent image carrier increases with increasing temperature due to the temperature characteristics of the binder that occupies most of the surface of the PC photosensitive member.

When the coefficient of friction of the latent image carrier rises as described above, the friction between the cleaning blade of the cleaning means and the surface of the latent image carrier becomes large, and particularly the temperature of the latent image carrier exceeds 45 ° C. And the friction coefficient sharply increases, the cleaning blade begins to vibrate, the edge portion of the cleaning blade is damaged, and when the blade is disposed opposite to the moving direction of the latent image carrier, The blade was turned over and the cleaning action was significantly reduced.

In order to solve such a problem, fine particles of a fatty acid metal salt (eg, zinc stearate) or a fluorine-based compound are externally added as a lubricant to the developer, and a thin film of the lubricant is formed on the surface of the latent image bearing member during development. Attempts have been made to reduce the friction coefficient on the surface of the latent image bearing member by forming the.

However, when these lubricants are externally added to a so-called two-component developer, which is composed of a mixture of toner particles and magnetic particles (carrier), the lubricant is used as a carrier after being used for a long time. Attached to the surface (carrier contamination)
However, the toner tribo becomes unstable, and problems such as background fog, reduction in image density, and in-machine contamination due to toner scattering occur. Particularly, in an image forming apparatus that obtains a full-color image, the background fog is transferred a plurality of times, resulting in extreme background fog.

On the other hand, it has been proposed to dispose a lubricant applying means before and after the cleaning means so as to reduce the friction coefficient of the surface of the image bearing member.
It is not preferable in terms of complication.

On the other hand, in recent years, with the widespread use of image forming apparatuses such as color copying machines for electrophotography, the applications thereof are widespread and the demands on the image quality thereof are becoming severe. In copying images such as general photographs, catalogs, and maps, it is required to reproduce extremely fine and faithful reproduction without damaging or breaking even a minute portion.

Recently, in an image forming apparatus such as a color copying machine for electrophotography which uses a digital image signal, a latent image is formed by gathering dots having a constant potential, and a solid portion, a halftone portion and a line. The parts are represented by changing the dot density. However, when the toner particles do not faithfully adhere to the dots and the toner particles protrude from the dots, it is impossible to obtain the gradation of the toner image corresponding to the ratio of the black and white dot densities of the digital latent image. There is a problem. Furthermore, in order to improve the image quality, if the dot size is reduced to improve the resolution, the reproducibility of the latent image formed from minute dots becomes more difficult, and the resolution and especially the gradation of the highlight part The image tends to be poor in sharpness and lack in sharpness.

Initially, the image quality is good, but the image quality may deteriorate during continuous copying or printing. It is considered that this phenomenon occurs because only toner particles that are easily developed are first consumed while copying or printing is continued, and toner particles having poor developability accumulate and remain in the developing machine.

Up to now, some developers have been proposed for the purpose of improving the image quality. JP-A-5
Japanese Patent Laid-Open No. 1-3244 proposes a non-magnetic toner intended to improve the image quality by regulating the particle size distribution. Among the toners, the toner having a particle size of 8 to 12 μm is mainly used, and it is relatively coarse. According to the study of the present inventors, it is difficult for the toner to have a uniform “paste” on the latent image. Further, from the characteristic that 5 μm or less is 30 number% or less and 20 μm or more is 5 number% or less, the point that the particle size distribution is broad also tends to deteriorate the uniformity.
In order to form a clear image using the toner having such coarse toner particles and having a broad particle size distribution, the toner particles are thickly stacked to fill the gaps between the toner particles to form an apparent image. It is necessary to increase the concentration,
There is also a problem that the amount of toner consumption required to obtain a predetermined image density increases.

Japanese Unexamined Patent Publication (Kokai) No. 54-72054 proposes a non-magnetic toner having a sharper distribution than the former, but the size of particles having an intermediate weight is 8.5 to 11.0.
There is still room for improvement as a high-resolution color toner that is as rough as μm and faithfully reproduces a minute dot latent image.

Japanese Unexamined Patent Publication (Kokai) No. 58-129437 proposes a nonmagnetic toner having an average particle size of 6 to 10 μm and a maximum number of particles of 5 to 8 μm, but particles of 5 μm or less are 15% by number or less. There is a tendency that an image lacking sharpness is formed.

According to the studies made by the present inventors, the toner particles of 5 μm or less clearly reproduce the minute dots of the latent image and have a main function of the dense toner paste on the entire latent image. It was discovered. In particular, in the electrostatic latent image on the photoconductor, electric field lines are concentrated, so that the electric field strength is higher at the edge portion which is the contour than inside, and the sharpness of the image quality is determined by the quality of the toner particles gathered at this portion. According to the study by the present inventors, it has been found that the amount of particles of 5 μm or less is effective for solving the problem of highlight gradation.

However, the toner particles having a particle size of 5 μm or less have a particularly strong adhesion to the surface of the latent image carrier, which makes cleaning difficult.

Further, when the printout is continuously performed, a low electric resistance substance such as paper powder or an ozone addition substance or toner may be fixed on the photosensitive member. For the purpose of scraping off such low electrical resistance substances and adhered toner, in JP-A-60-32060 or JP-A-60-136752, the BET specific surface area due to nitrogen adsorption is 0.5 to 30 m ² / g. It has been proposed to add the above inorganic fine powder as an abrasive.

Although this method is effective in avoiding the toner sticking phenomenon, in order to apply it to the small-diameter high-resistance color toner of the present invention, it is necessary to improve the cleaning stability without improving the charge stabilization. Was insufficient to achieve sex.

[0020]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a toner for developing an electrostatic charge image and an image forming method which solve the above problems.

An object of the present invention is to provide an electrostatic charge image developing toner having a high image density, excellent fine line reproducibility and highlight gradation, and an image forming method.

An object of the present invention is to provide an electrostatic charge image developing toner and an image forming method which do not change in cleaning performance even when used for a long time.

[0023]

The present invention has solved the above-mentioned problems by the following configurations.

The present invention provides a toner for developing an electrostatic charge image, which comprises toner particles and an external additive, wherein the external additive has a weight average particle diameter of at least 0.01 to 0.2 μm and is subjected to a hydrophobic treatment. Titanium particles (A), 0.02-0.5μ
organic resin particles (B) having a weight average particle diameter of 0.
The inorganic additive (C) has a weight average particle diameter of 5 to 2.5 μm, and the external additive has the following relationship (A) :( B) = 2: 1 to 10: 1 (A): (C) = 1: 1 to 5: 1, and the toner contains 15 to 40% by number of toner particles having a particle diameter of 2 to 5 μm. .

Further, in the present invention, (i) a developed image is formed on the surface of a latent image carrier containing an organic photoconductive substance with a toner, (ii) the developed image is transferred to a transfer material, and (ii)
i) In the image forming method in which after the transfer, the latent image bearing member is cleaned with a cleaning member, and (iv) the latent image bearing member after cleaning is repeatedly used, the toner contains toner particles and an external additive. The external additive has
Hydrophobized titanium oxide particles (A) having a weight average particle diameter of at least 0.01 to 0.2 μm and 0.02
Having organic resin particles (B) having a weight average particle diameter of ˜0.5 μm, the external additive satisfies the following relationship (A) :( B) = 2: 1 to 10: 1, Further, the toner contains 15 to 40% by number of toner particles having a particle diameter of 2 to 5 μm, and the cleaning member has a resin base material and 0.15 to 0.15% coated on the resin base material.
It relates to an image forming method having a polyamide resin coating layer containing low surface free energy fine particles having a weight average particle diameter of 2.0 μm.

Further, in the present invention, (i) a developed image is formed on the surface of a latent image carrier containing an organic photoconductive substance with a toner, (ii) the developed image is transferred to a transfer material, and (i)
ii) In the image forming method in which after the transfer, the latent image bearing member is cleaned with a cleaning member, and (iv) the latent image bearing member after cleaning is repeatedly used, the toner contains toner particles and an external additive. The external additive is
Hydrophobized titanium oxide particles (A) having a weight average particle diameter of at least 0.01 to 0.2 μm, 0.02
Organic resin particles (B) having a weight average particle diameter of 0.5 μm
And an inorganic compound (C) having a weight average particle diameter of 0.5 to 2.5 μm, and the external additive has the following relationship (A) :( B) = 2: 1 to 10: 1 ( A) :( C) = 1: 1 to 5: 1 is satisfied, and the toner contains 15 to 40% by number of toner particles having a particle diameter of 2 to 5 μm. It has a photosensitive layer containing a conductive substance and a protective layer formed on the surface side of the photosensitive layer, and the protective layer contains fluorine atom-containing resin particles in an amount of 5 to 40 based on the total weight of the protective layer.
The present invention relates to an image forming method characterized in that the image is contained in a weight percentage.

As a result of diligent investigations by the present inventors regarding the toner for developing an electrostatic image of the present invention, the toner and the cleaning blade are not affected by the surface property of the toner and the surface property (surface roughness) of the photoconductor. It was found that good images and stable cleaning characteristics can be obtained when minute voids of 0.1 to 2.5 μm are present in the pressure bonded portion.

As a means for producing the above-mentioned gap in the pressure-bonded portion between the photosensitive member and the cleaning blade, it is possible to control it by the surface roughness of the photosensitive member.
If the surface roughness of the photoconductor is larger than 2.0 μm, the image quality deteriorates.
In particular, problems such as poor reproduction of highlights and shakiness occur. On the other hand, when the surface roughness is small, it becomes difficult to control the roughness, and in addition, depending on how the surface is scraped, the voids are less than 0.1 μm. When the size becomes small, the pressure of the cleaning blade becomes too strong, and cleaning failure occurs due to the reversal of the blade, and sufficient cleaning characteristics cannot always be achieved only by controlling the surface roughness of the photoconductor.

Therefore, as a result of further studies by the present inventors, at least a weight average particle diameter of 0.5 to 0.5 was used as an external additive.
The developer containing 2.5 μm of the inorganic compound (C) is extremely excellent in cleaning and high image quality in various environments,
It has been found to provide good images. Here, the reason why the cleaning property becomes stable is that the excessive pressure bonding between the surface of the organic photoconductor and the cleaning blade is mitigated by the inorganic compound (C) acting as a spacer to obtain appropriate friction characteristics. .

However, by including the above-mentioned inorganic compound (C), although the initial cleaning characteristics are improved by several steps, the initial cleaning is required without improving the fluidity of the toner and stabilizing the charging of the toner. It was difficult to maintain the characteristics.

However, the hydrophobized titanium oxide particles (A) having a weight average particle diameter of 0.01 to 0.2 μm.
And by using the organic resin particles (B) having a weight average particle diameter of 0.02 to 0.5 μm in combination with the inorganic compound (C), stabilization of charge and fluidity are improved, which is extremely effective in improving cleaning characteristics. It was found to be effective.

Further, as a result of intensive studies by the present inventors regarding the image forming method of the present invention, 0.15 to 2.0 .mu.
It was found that a cleaning method using a cleaning blade coated with a polyamide resin containing a low surface free energy fine powder having a weight average diameter of m is extremely effective in stabilizing the slipperiness between the photoconductor and the cleaning blade. Of.

However, although the cleaning characteristics are surely improved by adopting the above-mentioned cleaning blade, particularly when the toner having a particle size of 2 to 5 μm in the present invention contains 15 to 40% by number distribution, especially under low humidity. So, although the cleaning property is good in the initial stage, the latitude of the cleaning property becomes narrower due to the durability, and cleaning failure due to the durability (toner slipping)
It was found that the toner tends to be generated, and sufficient cleaning characteristics cannot be achieved without improving the toner.

Therefore, as a result of further studies by the present inventors, as an external additive, at least a weight average particle diameter of 0.01
To 0.2 μm of hydrophobized titanium oxide fine particles (A) and weight average particle diameter of 0.2 to 0.5 μm of organic resin particles (B) are included to prevent toner charge-up especially under low humidity. It was found that by doing so, excellent images can be provided with excellent cleaning and high image quality under various environments.

Further, as a result of diligent studies by the present inventors regarding another image forming method of the present invention, in an electrophotographic photosensitive member having a photosensitive layer and a protective layer on a conductive support, fluorine is formed on the surface of the photosensitive member. Atom-containing resin fine particles are contained, and 0.1 to the pressure-bonded portion between the photosensitive member and the cleaning blade.
It has been found that good images and stable cleaning characteristics can be obtained while maintaining the durability characteristics of the photoconductor in the presence of microscopic voids of 2.5 μm. Therefore, at least an inorganic compound (C) having a weight average particle diameter of 0.5 to 2.5 μm is used as an external additive, and further, hydrophobized titanium oxide particles (having a weight average particle diameter of 0.01 to 0.2 μm ( By using A) and the organic resin particles (B) having a weight average particle diameter of 0.02 to 0.5 μm in combination with the inorganic compound (C), stabilization of charging and fluidity are improved, and cleaning characteristics are improved. It was found to be extremely effective for.

Here, the reason why the cleaning property is stabilized in the other image forming method of the present invention is that the corona product generated on the surface of the photoconductor and the paper dust attached thereto can be scraped off.

The components of the present invention will be described in detail below.

The inorganic compound (C) as the external additive according to the present invention may be any one as long as it has a weight average particle diameter of 0.5 to 2.5 μm. Further, the starting material, manufacturing method, etc. are not limited. The inorganic compound (C) is
If it is less than 0.5 μm, the cleaning blade cannot follow the surface of the photoconductor when the surface roughness of the photoconductor is rough, so that the cleaning blade often slips through the cleaning blade, and uneven charging occurs during latent image formation, and image deterioration easily occurs. Become. 2.
If it is larger than 5 μm, it is excessively cleaned by the cleaning blade, and it is difficult for the cleaning blade to collect at the blade edge portion, and the spacer function is deteriorated, resulting in poor efficiency.

Examples of the material of the inorganic compound (C) usable in the present invention include inorganic oxides such as silicic acid fine powder, alumina fine powder, titanium oxide fine powder, zirconium oxide fine powder and magnesium oxide fine powder, and boron nitride. Examples thereof include fine powders, fine powders of aluminum nitride, fine powders of carbon nitride, and inorganic resin particles such as silicone resin particles.

Further preferred inorganic compounds (C) include
Examples thereof include calcium titanate, strontium titanate, barium titanate, magnesium titanate, cerium oxide, zirconium oxide, aluminum oxide, titanium oxide, zinc oxide and calcium carbonate.

In the present invention, hydrophobized titanium oxide particles (A) having a weight average particle diameter of 0.01 to 0.2 μm and a weight average particle diameter of 0.02 to 0.
It is also one of the characteristics that the organic resin particles (B) of 5 μm are contained.

By containing the titanium oxide particles (A) and the organic resin particles (B), stabilization of charge and fluidity are improved, which is extremely effective for improving cleaning characteristics. This is not possible with the known hydrophobic silica as a flow improver.

The reason for this is that the silica fine particles themselves have a strong negative chargeability, whereas the titanium fine particles have a substantially neutral chargeability. JP-A-59-5
No. 2255 proposes to add hydrophobic titanium oxide, but titanium oxide fine particles originally have a smaller surface activity than silica, and the hydrophobicization in the gas phase has not always been sufficiently performed. . Furthermore, when a large amount of a treating agent or a highly viscous treating agent is used, the degree of hydrophobicity is surely increased, but particles are coalesced with each other and the fluidity-imparting ability is deteriorated. A balance between stabilization and imparting liquidity has not necessarily been achieved.

When the titanium oxide fine particles are mechanically dispersed in an aqueous system so as to have a primary particle diameter and the coupling agent is hydrolyzed for surface treatment, the particles are coalesced with each other rather than in the gas phase. It was found that the titanium particles are surface-treated in the state of almost primary particles because the charging repulsion between particles is caused by the treatment.

As described above, in the present invention, it is preferable to treat the surface of titanium oxide while hydrolyzing the coupling agent in an aqueous system. At this time, in order to disperse the titanium oxide fine particles into the primary particles, mechanical treatment is performed. Since force is applied, it is not necessary to use a coupling agent that generates gas like chlorosilanes and silazanes, and furthermore, until now, particles could not be used together in the gas phase. Also, a highly viscous coupling agent can be used, and the effect of hydrophobization is great.

The coupling agent usable in the present invention may be a silane coupling agent or a titanium coupling agent. Particularly preferably used is a silane coupling agent, which is represented by the following general formula (1) R _m SiY _n (1) R: an alkoxy group m: an integer of 1 to 3 Y: an alkyl group, a vinyl group, a glycidoxy group or methacryl. Hydrocarbon group containing a group n: an integer of 1 to 3 and represented by, for example, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane. , Methyltriethoxysilane, isobutyltrimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylmethoxysilane, hydroxypropyltrimethoxysilane, phenyltrimethoxysilane, n-hexadecyltrimethoxysilane, n-octadecyltrimethoxysilane It can be mentioned.

[0047] Particularly preferred silane coupling agent in the present invention is represented by the following general formula _{(2) C n H 2n +} 1 -Si- (OC m H 2m + 1) 3 ... (2) n: 4~12 m: It is represented by 1-3.

Here, when n in the general formula (2) is smaller than 4, the treatment is easy, but the hydrophobicity cannot be sufficiently achieved, and when n is larger than 12, the hydrophobicity is sufficient. The coalescence of the titanium oxide particles increases, and the ability to impart fluidity decreases.

Although m is preferably 1 to 3 (preferably 1 to 2), when m is larger than 3, the reactivity is lowered and the hydrophobic property is not sufficiently achieved.

The treatment amount of the hydrophobized titanium oxide particles (A) is preferably 1 to 50 parts by weight, more preferably 3 to 4 parts by weight, based on 100 parts by weight of the titanium oxide particles.
It is preferable to use 0 part by weight, and the hydrophobicity is preferably 4
It is good to set it to 0 to 80%, more preferably 50 to 80%.

If the degree of hydrophobicity is less than 40%, the amount of charge is greatly reduced by leaving it in high humidity for a long period of time, a mechanism for promoting charge on the hardware side is required, the apparatus becomes complicated, and the degree of hydrophobicity is 80. If it exceeds%, it becomes difficult to control the charge of titanium oxide itself, and as a result, the toner tends to be charged up in low humidity.

Further, the weight average particle diameter of the titanium oxide particles (A) used in the present invention is 0.01 from the viewpoint of imparting fluidity.
.About.0.2 .mu.m, preferably 0.015 to 0.15 .mu.m. If the particle size is larger than 0.2 μm, toner charging becomes non-uniform due to poor fluidity, resulting in toner scattering and fog.

When the weight average particle diameter of the titanium oxide particles (A) is larger than 0.01 μm, the titanium oxide particles (A) are easily embedded in the toner surface, the toner is deteriorated quickly, and the durability is deteriorated. This tendency is more remarkable in the sharp melt color toner used in the present invention.

In the present invention, the method for treating the titanium oxide particles (A) is not particularly limited, but titanium oxide is mechanically dispersed in an aqueous system so as to have a primary particle size,
A method in which the coupling agent is hydrolyzed and treated is effective, and is preferable in that no solvent is used.

Further, in the present invention, the treated titanium oxide particles (A) have a feature that the light transmittance at a light length of 400 nm is preferably 40% or more, more preferably 50% or more.

That is, when the titanium oxide particles of the present invention are used by being externally added to a full-color toner and the transparency to visible light is less than 40%, the projected image of the OHP will be sharpened and a clear image will be obtained. I can't.

The titanium oxide particles (A) of the present invention are suitable even when the toner has a small particle size. When the particle size of the toner is reduced, the surface area per weight is increased, and excessive charging due to rubbing tends to occur. On the other hand, the effect of titanium oxide fine particles that can control charge and impart fluidity is great.

The organic resin particles (B) used in the present invention have a polarity opposite to that of the colorant-containing resin particles (toner particles) and have a weight average particle diameter of 0.02 to 0.5 μm, preferably The thickness is preferably 0.04 to 0.4 μm.

The reason for this is that the charge-up of the toner used in the present invention is neutralized by the above-mentioned organic resin particles (B).

Furthermore, by adding the organic resin particles (B), the rise of charging of the toner is promoted, and a very stable charging characteristic is achieved from the initial stage.

The reason for this is not clear yet, but it is presumed as follows. That is, the organic resin particles (B) are strongly attracted and charged to the charging member rather than the toner particles when the toner is rubbed against the charging member such as a carrier. Therefore, the rising of the charge of the opposite polarity toner particles is promoted. On the other hand, once it stands up, on the contrary, it is more strongly attracted to the toner particles than the charge imparting member, and the function of neutralizing excessive charge works.
The toner having the constitution of the present invention can maintain the rising of charge and the saturated charge amount level in a good and stable manner in various environments.

In order to make the above effect more effective, the organic resin particles (B) should have a particle size distribution of 0.02 to 0.02.
It is preferable to have two peaks in the regions of 0.2 μm and 0.3 to 0.8 μm. The abundance ratio of the larger peak is 20% by weight or less and 2% by weight or more, preferably 13% by weight or less and 3% by weight or more. When the particle diameter is smaller than the above range, the organic resin particles adhere too strongly to the colorant-containing resin particles or are embedded therein, and the above-mentioned effects disappear. On the other hand, when it is larger than the above range, the dispersion becomes non-uniform or liberated, and the effect disappears.

In the present invention, the organic resin particles (B) preferably exhibit 0.1-5, based on the weight of the toner particles in the toner, in order to ensure their performance and to have a stable negative charging property. 0.0% by weight, more preferably 0.15%
It is preferable to contain 3.0% by weight.

Further, the organic resin particles (B) of the present invention are suitable even when the toner has a small diameter.

That is, when the diameter of the toner is reduced, the number of contact points between the toner and the carrier is increased, which easily causes the carrier spent, or the number of contact points between the toner and the toner is increased, and the toner blocking is easily caused. On the other hand, as the organic resin particles (B), the spherical organic resin particles (B) having an appropriate size of 0.02 to 0.2 μm serve as a good spacer and exert a good effect on the above-mentioned problems. For the toner blocking, it is more effective to use the opposite polarity resin particles having a higher Tg than the toner resin.

As described above, there are some examples in which resin particles having opposite polarities are added to the toner.
4-45135 and Japanese Patent Publication No. 52-32256 propose to add colorless resin particles smaller than toner particles.

However, in these examples, the toner and the opposite polarity resin particles behave separately and the toner adheres to the latent image portion during development, whereas the opposite polarity resin particles adhere to the background portion.

That is, the reverse polarity resin particles have a function of promoting the charging of the toner. However, in the present invention, the reverse polarity resin particles that are sufficiently smaller than the toner particle size are used, and finally, the toner is strongly adhered to the toner and integrally developed, and the transfer residue has 0.3 to 0.8 μm. The resin particles on the relatively coarse side are appropriately left, and the cleaning property is further improved by the coexistence with the above-mentioned inorganic compound or the combination with the above-mentioned cleaning blade. Is different.

In Japanese Patent Publication No. 2-3172, etc., a system used for the purpose of not lowering the charge of the toner is proposed, but in the present invention, the non-magnetic color toner which is apt to be excessively charged is rather used. It is a different invention because it is positively used to reduce the charge.

The monomer constituting the organic resin particles (B) used in the present invention is not particularly limited, but it needs to be selected in consideration of the charge amount of the toner and the like. The following monomers can be mentioned as specific examples of the addition-polymerizable monomer that can be used in the organic resin particles (B) used in the present invention.

(I) Styrene and its derivatives such as methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, triethyl styrene, propyl styrene, butyl styrene, hexyl styrene, heptyl styrene and octyl styrene; Styrene, chlorostyrene,
Examples thereof include halogenated styrenes such as bromostyrene, dibromostyrene and iodostyrene, as well as nitrostyrene, acetylstyrene and methoxystyrene.

(Ii) Addition-polymerizable unsaturated carboxylic acids,
Addition-polymerizable unsaturated aliphatic monocarboxylic acids such as acrylic acid, methacrylic acid, α-ethyl acrylic acid, crotonic acid, α-methyl crotonic acid, α-ethyl crotonic acid, isocrotonic acid, tiglic acid, ungeric acid; and And addition-polymerizable unsaturated dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, glutaconic acid, and dihydromuconic acid.

(Iii) Further, a metal chloride of these carboxylic acids can be used, and this metal chloride can be carried out after completion of the polymerization.

(Iv) Esterification products of the above-mentioned addition-polymerizable unsaturated carboxylic acid with alcohols such as alkyl alcohol, halogenated alkyl alcohol, alkoxyalkyl alcohol, aralkyl alcohol and alkenyl alcohol can be mentioned. Then, as specific examples of the alcohol, methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, amyl alcohol,
Alkyl alcohols such as hexyl alcohol, heptyl alcohol, octyl alcohol, nonyl alcohol, dodecyl alcohol, tetradecyl alcohol, hexadecyl alcohol; halogenated alkyl alcohols obtained by partially halogenating these alkyl alcohols; methoxyethyl alcohol, ethoxyethyl alcohol, ethoxy Alkoxyalkyl alcohols such as ethoxyethyl alcohol, methoxypropyl alcohol and ethoxypropyl alcohol; aralkyl alcohols such as benzyl alcohol, phenylethyl alcohol and phenylpropyl alcohol; alkenyl alcohols such as allyl alcohol and crotonyl alcohol.

(V) Amides and nitriles derived from the above-mentioned addition-polymerizable unsaturated carboxylic acids; aliphatic monoolefins such as ethylene, propylene, butene and isobutylene; vinyl chloride, vinyl bromide, vinyl iodide, 1,2 −
Dichloroethylene, 1,2-dibromoethylene, 1,2
-Diiodoethylene, isopropenyl chloride, isopropenyl bromide, allyl chloride, allyl bromide, vinylidene chloride,
Halogenated aliphatic olefins such as vinyl fluoride and vinylidene fluoride; 1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2 , 4-hexadiene, 3-
Examples include conjugated diene-based aliphatic diolefins such as methyl-2,4-hexadiene.

(Vi) Vinyl acetates; vinyl ethers; and nitrogen-containing vinyl compounds such as vinylcarbazole, vinylpyridine and vinylpyrrolidone.

As the organic resin particles (B) according to the present invention, those obtained by polymerizing one kind or two or more kinds of these monomers can be used.

The organic resin particles (B) used in the present invention are not limited to using only one type, and a plurality of types can be used in combination.

As the method for producing the organic resin particles (B) used in the present invention, spherical fine particles such as a spray dry method, a suspension polymerization method, an emulsion polymerization method, a soap-free polymerization method, a seed polymerization method and a mechanical grinding method are used. Any method that can be used can be used. Among these, a particularly suitable one is a soap-free polymerization method which has no residual emulsifier, does not hinder the charging property of the toner, has a small specific electric resistance, and has little environmental fluctuation, but is particularly limited to this. is not.

In order to make the organic resin particles (B) used in the present invention have two peaks in the particle size distribution, two kinds of particles having different particle sizes may be dry blended or wet blended and then dried, but preferably, polymerization is performed. It is more preferable that the primary particles are appropriately coalesced to achieve two peaks when the emulsion is dried and then dried. If necessary, heat treatment or crushing treatment may be performed.

The organic resin particles (B) may be subjected to particle surface treatment, if necessary. As a method of surface treatment,
A method of surface-treating a metal such as iron, nickel, cobalt, copper, zinc, gold, or silver by a surface treatment method such as a vapor deposition method or a plating method, or a metal oxide of the above metal or magnetic material or conductive zinc oxide, etc. A method of fixing by ion adsorption or external addition, a pigment or a dye, and a triboelectrically chargeable organic compound such as a polymer resin may be supported by coating or external addition.

The molecular weight distribution of the organic resin particles (B) used in the present invention must have a peak molecular weight in the range of 10,000 to 5,000,000, and preferably in the range of 20,000 to 1,000,000. When the peak molecular weight is larger than 5,000,000, the fixability of the color toner is adversely affected, and when it is smaller than 10,000, the magnetic particles are contaminated or the blocking resistance is deteriorated.

In the present invention, the addition amount of the titanium oxide fine particles (A), the organic resin particles (B) and the inorganic compound (C) has the following relationship (A) :( B) = 2: 1 to 10: 1 (A ) :( C) = 1: 1 to 5: 1, and preferably the following relationship (A) :( B) = 2: 1 to 10: 1 (A) :( C) = 2. : 1 to 5: 1 is preferable, and more preferably the following relation (A) :( B) = 3: 1 to 10: 1 (A) :( C) = 2: 1 to 5: 1 is satisfied. Good to do.

In the present invention, in the case of using a cleaning blade having a resin base material coated with a polyamide coat layer containing low surface free energy fine particles, which will be described later,
Since the slidability between the cleaning blade and the latent image carrier is extremely stable, it is preferable but not necessary to use the above-mentioned inorganic compound (C) as an external additive for the toner.

In this case, the addition amount of the titanium oxide fine particles (A) and the organic resin particles (B) needs to satisfy the following relationship (A) :( B) = 2: 1 to 10: 1. It is preferable to satisfy the following relationship (A) :( B) = 3: 1 to 10: 1.

If the amount of the external additive added is out of the above range, the additive becomes nonuniform and the cleaning characteristics and fluidity are impaired, which is not preferable.

A charge control agent may be added to the toner particles according to the present invention in order to stabilize the charge characteristics. At that time, a colorless or pale color charge control agent that does not affect the color tone of the toner is preferable. As the negative charge control agent at that time, for example, a metal complex of alkyl-substituted salicylic acid (for example, di-tert.
-Chromium or zinc complexes of butylsalicylic acid). When the negative charge control agent is blended with the toner particles, it is added to 100 parts by weight of the binder resin.
It is preferable to add 1 to 10 parts by weight, preferably 0.5 to 8 parts by weight.

When a toner according to the present invention and magnetic particles (carriers) are mixed to prepare a two-component developer, the mixing ratio is 2 to 10% by weight as the toner concentration in the developer,
Good results are usually obtained when the amount is preferably 3 to 9% by weight. If the toner concentration is less than 2% by weight, the image density is low and it is not practical. If it exceeds 10% by weight, fog and scattering in the machine are increased and the useful life of the developer is shortened.

As the binding substance used in the toner particles of the present invention, various material resins conventionally known as electrophotographic toner binding resins are used. For example, polystyrene,
Styrene-butadiene copolymers, styrene-acrylic copolymers and other styrene-based copolymers, polyethylene, ethylene-vinyl acetate copolymers, ethylene-vinyl alcohol copolymer-based ethylene copolymers, phenolic resins , Epoxy resin, acrylic phthalate resin, polyamide resin, polyester resin, and maleic acid resin. The manufacturing method of any resin is not particularly limited.

Among these resins, particularly when a polyester resin is used, the effect of the present invention is great. That is, the polyester-based resin has excellent fixability and is suitable for a color developer.

Next, the following equation

[0092]

[Outer 1] (In the formula, R is an ethylene or propylene group, x and y are each an integer of 1 or more, and the average value of x + y is 2
It is -10. ), A bisphenol derivative or a substitution product represented by the formula (1) is used as a diol component, and a carboxylic acid component composed of a carboxylic acid having a valence of 2 or more or an acid anhydride thereof or a lower alkyl ester thereof (eg, fumaric acid, maleic acid, maleic anhydride, phthalate). A polyester resin obtained by copolymerizing an acid, terephthalic acid, trimellitic acid, and pyromellitic acid) is more preferable because it has sharp melting characteristics.

As the colorant used in the toner particles used in the present invention, widely known dyes and pigments such as phthalocyanine blue, indus blue, peacock blue, permanent red, lake red, rhodamine lake, Hansa yellow, permanent yellow and benzidine yellow are widely used. Can be used. As its content, OHP
The amount is preferably 12 parts by weight or less, and more preferably 0.5 to 9 parts by weight, based on 100 parts by weight of the binder resin so as to sensitively reflect the light transmittance of the film.

In the present invention, in order to faithfully achieve fine line reproduction and highlight reproduction in the toner particle size distribution, 15 to 40% by number of toner particles having a particle size of 2 to 5 μm,
It is also one of the characteristics that it is preferably 20 to 35% by number.

15% by number of toner particles having a particle size of 2 to 5 μm
If it is smaller, the fidelity of the manuscript will be impaired, and 40% more
If it exceeds the range, fog and toner scattering increase, and even when combined with the toner external additive of the present invention, the toner slips through the cleaning blade and the cleaning characteristics deteriorate.

When the toner of the present invention is used as a two-component developer, the magnetic particles (carrier) used are, for example, surface-oxidized or unoxidized iron, nickel, copper, zinc, cobalt, manganese, chromium, Magnetic metals such as rare earths and their alloys or oxides and ferrites can be used. There are no particular restrictions on the manufacturing method.

In the present invention, resin-coated magnetic particles obtained by coating the surfaces of magnetic particles with a resin can be used. As a method for coating the surfaces of the magnetic particles with a resin, a coating material such as a resin is used in a solvent. Any conventionally known method can be applied, such as a method in which the particles are dissolved or suspended and then applied and attached to the magnetic particles, or a method in which they are simply mixed in powder form. For the stability of the coating layer, it is preferable that the coating material be dissolved in a solvent.

The material for coating the surface of the magnetic particles varies depending on the toner material, but, for example, an amino acrylate resin, an acrylic resin, or a copolymer of these resins and a styrene resin is suitable. As the negatively charged resin, silicone resin, polyester resin, polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride and the like are preferable because they are located on the negative side in the charging series, but are not necessarily limited thereto. Suitable for the present invention are acrylic resins or copolymers of those resins and styrene resins.

The most suitable material for the magnetic particles used in the present invention is a composition of 98% or more of Cu-Zn-Fe (composition ratio (5-20) :( 5-20) :( 30-80)). Ferrite particles, which are capable of easily smoothing the surface, stabilizing the charge imparting ability, and stabilizing the coat.

The coating amount of the above compound may be appropriately determined so that the charge imparting property of the magnetic particles satisfies the above-mentioned conditions, but generally, the total amount is 0.1 to 3 with respect to the magnetic particles of the present invention.
It is 0% by weight (preferably 0.3 to 20% by weight). It is preferable that the weight average particle diameter of these magnetic particles is 35 to 65 μm, preferably 40 to 60 μm. further,
A good image can be maintained when the weight distribution of 26 μm or less is 2 to 6%, the weight distribution of 35 to 43 μm is 5 to 23%, and the 74 μm or more is 2% or less.

Further, in order to prepare the toner particles according to the present invention, a thermoplastic resin, if necessary, is sufficiently mixed with a pigment or dye as a colorant, a charge control agent, and other additives by a mixer such as a ball mill. Then melt using a heat kneader such as heating roll, kneader, extruder.
The pigments or dyes may be dispersed or dissolved in the kneading and kneading meat to make the resins compatible with each other, and after cooling and solidification, pulverization and strict classification may be performed.

FIG. 1 shows a cleaning blade in which the surface of a blade substrate is coated with a polyamide resin coating layer containing low surface free surface energy fine particles used in the image forming method of the present invention.

In the image forming method of the present invention, the polyamide resin coating layer 13 for coating the blade base material 12 fixed to the blade support 11 of the cleaning blade 1 is coated.
0.01 to 2.0 μm, preferably 0.0
Examples of the low surface free energy fine particles having a weight average particle diameter of 5 to 1.5 μm include fluororesin powder and silicon-containing compounds.

The particle size of the low surface free energy fine particles is 0.
When it is less than 01, the low surface free energy fine particles are difficult to be exposed from the surface of the coating layer, and the effect of the addition is not sufficient and when it exceeds 2.0 μm, it is uniformly dispersed in the polyamide resin coating layer. It becomes difficult and is easily released from the coat layer, and the effect does not last long.

Examples of the fluorine-based resin powder include carbon fluoride, polytetrafluoroethylene, polyvinylidene fluoride, and tetrafluoroethylene-vinylidene fluoride copolymer.

As the silicon-containing compound, silica fine powder,
Examples thereof include silica-alumina eutectic fine powder and silicone resin particles. Among these, particularly preferred is one in which 1 is a silicon atom.
Silicone resin particles having a siloxane structure having a number of alkyl groups are preferable because the particle size distribution can be sharpened.

FIG. 2 shows a latent image carrier used in the image forming method of the present invention.

In another image forming method of the present invention, the latent image carrier is a photosensitive layer 23 and a protective layer 2 on a conductive support 21.
4 is provided, at least the protective layer 24 contains fluorine atom-containing resin particles in order to reduce the friction resistance of the surface of the latent image carrier 2, and the protective layer 24 is mechanically polished. The average surface roughness of the protective layer 24 is preferably JI
0.1 μm as shown by 10-point average surface roughness R _Z (hereinafter simply referred to as average surface roughness) defined by S standard B061
It is preferably 2.5 μm or more and more preferably 0.1 μm or more and 1.5 μm or less.

The average surface roughness of the protective layer of the latent image carrier is 2.5 μm.
If it is larger than m, a gap is generated between the surface of the latent image carrier 2 and the cleaning blade 1, and the residual toner remaining after transfer has a fine particle size and slips through, resulting in poor cleaning.

When the average surface roughness is 1.5 μm or less, the friction between the cleaning blade 1 and the surface of the latent image carrier 2 is sufficiently small, and no image defect appears even after repeated use. The highlight reproduction will be very good.

When the average surface roughness is smaller than 0.1 μm, the friction between the cleaning blade 1 and the surface of the latent image carrier 2 is hardly alleviated, and the fluorine atom-containing fine particles themselves appear on the surface to reduce the friction. The effect of causing it is not recognized. Therefore, a cleaning failure such as reversal of the cleaning blade or crossing of the blade edge portion causes the average surface roughness of the surface of the latent image carrier containing the fluorine atom-containing resin fine particles in the protective layer to be 0.1 μm or more and 2.5 μm or less. By doing so, it can be prevented.

The content of fluorine atom-containing resin fine particles capable of effectively lowering the friction coefficient of the surface of the latent image bearing member in the protective layer is 5 to 40% by weight, preferably 10 to 40% by weight based on the total weight of the protective layer. % By weight. The thickness of the protective layer is preferably in the range of 0.05 μm to 8.0 μm, more preferably in the range of 0.5 μm to 6.0 μm.

In the present invention, when the fluorine atom-containing resin fine particles are also contained in the photosensitive layer 23 portion, the photosensitive layer 23 is thicker than the thin protective layer 24, so that the content of the fine particles is limited. Specifically, the content rate in the photosensitive layer 23 is
It is preferably 10% by weight or less, more preferably 7% by weight or less, based on the total weight of the photosensitive layer.

Even when the amount of fluorine atom-containing resin fine particles in the photosensitive layer 23 is limited, when the total thickness of the photosensitive layer 23 is large,
When photocarriers are generated mainly on the support side of the photosensitive layer 23, sensitivity deterioration due to light scattering and deterioration of image uniformity are remarkable. On the other hand, if the photosensitive layer 23 is too thin, the sensitivity and the charging ability are lowered due to the increase in the electric capacity of the photosensitive layer 2. Further, even when the fine particles are not contained in the photosensitive layer 23, the photosensitive layer cannot be extremely thickened.
The reason is that since the protective layer 24 containing the fine particles is laminated on the photosensitive layer 23, the protective layer 24 serves as a light scattering layer, and particularly when the photo or carrier is mainly generated on the support side of the photosensitive layer, This is because the farther the generation portion of the photocarrier is from the light scattering layer, that is, the thicker the photosensitive layer 23, the longer the optical path length of light after scattering and the greater the influence of light scattering.

Therefore, the total thickness of the photosensitive layer and the protective layer is preferably 10 to 35 μm, more preferably 15 to 30 μm.
μm. It is preferable that the amount of the fine particles contained in the photoreceptor is as small as possible, so that the average content of the fine particles in the total film thickness of the photosensitive layer 23 and the protective layer 24 is based on the total weight of the photosensitive layer and the protective layer. Is 17.5% by weight or less.

Fluorine atom-containing resin fine particles used in the electrophotographic photosensitive member of the present invention are polytetrafluoroethylene,
Polychlorotrifluoroethylene, polyvinylidene fluoride, polydichlorodifluoroethylene, tetrafluoroethylene-perfluoroalkylvinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-ethylene copolymer, and tetra It is composed of one or more selected from a fluoroethylene-hexafluoropropylene-perfluoroalkyl vinyl ether copolymer. It is possible to use commercially available fluorine atom-containing resin fine particles as they are. Those having a molecular weight of 30,000 to 5,000,000 can be used, and those having a particle size of 0.01 to 10 μm, preferably 0.05 to 2.0 μm can be used.

The photosensitive layer 23 of the electrophotographic photosensitive member of the present invention contains at least a charge generating material and a charge transporting material as an organic photoconductive substance. Examples of charge generating materials include phthalocyanine pigments, polycyclic quinone pigments, trisazo pigments,
Disazo pigment, azo pigment, perylene pigment, indigo pigment, quinacridone pigment, azulenium salt dye, squalium dye, cyanine dye, pyrylium dye, thiopyrylium dye, xanthene dye, quinoneimine dye, triphenylmethane dye, styryl dye, selenium, selenium-tellurium Examples include alloys, amorphal silicon, and cadmium sulfide.

Examples of the charge transport material include pyrene compounds, N-alkylcarbazole compounds, hydrazone compounds, N, N-dialkylaniline compounds, diphenylamine compounds, triphenylamine compounds, triphenylmethane compounds, pyrazoline compounds, styryl compounds, Examples include stilbene compounds, polynitro compounds, polycyano compounds, and pendant polymers in which these compounds are fixed on a polymer.

In some cases, the above-mentioned fluorine atom-containing resin fine particles, charge generating material, charge transporting material and the like are dispersed and contained in a binder resin having film forming properties to form each protective layer, photosensitive layer and the like. Many. Such binder resins include polyester, polyurethane, polyacrylate, polyethylene, polystyrene, polybutadiene, polycarbonate, polyamide, polypropylene, polyimide, phenol resin, acrylic resin, silicone resin, epoxy resin, urea resin, allyl resin, alkyd resin. , Polyamide-imide, nylon, polysulfone, polyallyl ether, polyacetal, butyral resin.

Next, the layer structure of the latent image carrier of the present invention will be described. The conductive support 21 is made of iron, copper, gold, silver, aluminum, zinc, titanium, lead, nickel, tin, antimony,
A metal or alloy such as indium, an oxide of the metal, carbon, or a conductive polymer can be used. The shape includes a drum shape such as a cylindrical shape and a cylindrical shape, a belt shape, and a sheet shape. The conductive material may be molded and processed as it is, used as a paint, vapor-deposited, or processed by etching or plasma treatment. In the case of paint, not only the metals and alloys mentioned above but also paper and plastic are used as the support.

Photosensitive layer 23 in latent image carrier 2 of the present invention
May have a single-layer structure or a laminated structure. In the case of the laminated structure, it is composed of at least the charge generation layer 23a and the charge transport layer 23b. However, when the charge generation layer 23a is provided on the conductive support 21 side and in the charge transport layer 2
The charging polarity and the polarity of the toner used are different from when 3b is provided. The thickness of the charge generation layer 23a is preferably 0.001 to 6 μm, more preferably 0.
It is 01 to 2 μm. The content of the charge generating material contained in the charge generating layer 23a is preferably 10 to 100% by weight, and more preferably 50 to 100% by weight, based on the total weight of the charge generating layer. The thickness of the charge transport layer is the thickness of the photosensitive layer 23 minus the thickness of the charge generation layer 23a. The content of the charge transport material contained in the charge transport layer 23b is preferably 20 to 80% by weight, and more preferably 30 to 70% by weight, based on the total weight of the charge generation layer.

An undercoat layer 22 may be provided between the conductive support 21 and the photosensitive layer 23. The undercoat layer 22 functions as a charge injection control at the interface and as an adhesive layer. Subbing layer 22
Is mainly composed of a binder resin, but may contain the above-mentioned metals or alloys, or their oxides, salts, surfactants and the like. As the binder resin for forming the undercoat layer 22, those mentioned as the binder resin for the photosensitive layer 23 can be used, and the thickness of the undercoat layer is preferably 0.05 to 7 μm, more preferably 0. It is 1 to 2 μm.

As described above, the protective layer is always provided on the photosensitive layer and is composed of resin fine particles containing at least a high concentration of fluorine atoms and a binder resin.

As a method for producing the latent image carrier used in the present invention, a method such as vapor deposition or coating is used. The coating method can form a wide range of films from thin films to thick films, and can form films of various compositions. Specifically, coating is carried out using a coating method such as bar coater, knife coater, dip coating, spray coating, beam coating, electrostatic coating, roll coater, attritor or powder coating.

The paint used for applying the protective layer is
It is obtained by dispersing the fluorine atom-containing resin fine particles in a binder resin and a solvent. As a dispersion method, a method such as a ball mill, ultrasonic wave, Peyton shaker, red devil, or sand mill is used. The same dispersion method can be used when the conductive fine powder, the pigment, and the charge generation material are pigments.

The measuring method used in the present invention will be described below.

(1) Method for measuring toner particle size distribution The toner particle size distribution can be measured by various methods.
In the present invention, a Coulter counter is used.

As a measuring device, a Coulter counter T
An interface (made by Nikkaki) and a CX that outputs number distribution and volume distribution using A-II type (made by Coulter)
-1 Connect a personal computer (made by Canon),
As the electrolytic solution, a 1% NaCl aqueous solution is prepared using first grade sodium chloride. As a measuring method, the electrolytic aqueous solution 100
Add a surface active agent as a dispersant, preferably 0.1 to 5 ml of alkylbenzene sulfonate, to ~ 150 ml,
Further, 2 to 20 mg of the measurement sample is added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment for about 1 to 3 minutes by an ultrasonic disperser, and a Coulter Counter TA-II type is used to form a 100 μm aperture as an aperture, and a particle number of 2 to 40 μm is used as a reference. The particle size distribution was measured and then the value according to the invention was determined.

[0129] (2) using a particle size measuring method apparatus measuring apparatus Coulter counter N4 type and as a dispersion ultrasonic generator Corporation Tomy Seiko UD-200 type as the external additive.

Method An appropriate amount of sample was put into 30 to 50 ml of distilled water to which a trace amount of a surfactant was added, and the output from the ultrasonic generator was 2 to 2.
Disperse at 6 for about 2 to 5 minutes. The suspension in which the sample is dispersed is transferred to a cell, waits for air bubbles to escape, and is set on the Coulter counter whose measurement temperature is set to 50 ° C. in advance. In order to keep the sample at a constant temperature, measurement is started after 10 to 20 minutes, and the volume average particle size distribution is obtained.

(3) Measurement of Hydrophobicity The methanol titration test is an experimental test for confirming the hydrophobization degree of titanium oxide fine powder having a hydrophobized surface.

The "methanol titration test" defined in this specification for evaluating the hydrophobicity of the treated titanium oxide fine powder is performed as follows. Titanium fine powder 0.2
g are added to 50 ml of water in an Erlenmeyer flask with a volume of 250 ml. Methanol is titrated from the burette until the total amount of titanium oxide is wet. At this time, the solution in the flask is constantly stirred with a magnetic stirrer. The end point is observed by suspending the total amount of fine titanium oxide powder in the liquid, and the degree of hydrophobization is expressed as the percentage of methanol in the liquid mixture of methanol and water when the end point is reached.

(4) Method of measuring transmittance 1. Sample 0.10g Alkyd resin 13.20g * 1 Melamine resin 3.30g * 2 Thinner 3.50g * 3 Glass media 50.00g * 1 Dainippon Ink & Chemicals Beckosol 1323-60-E
L * 2 Super Nippon Beckamine J-820 manufactured by Dainippon Ink
60 * 3 Kansai Paint's Amilak thinner The above composition is sampled in a 150 cc mayonnaise bottle and dispersed for 1 hour with a Red Devil paint conditioner.

2. After dispersion, 2 mi on PET film
Apply with a doctor blade of 1.

3.2. Is heated at 120 ° C. for 10 minutes to perform baking. 4.3. The sheet is measured with a U-BEST 50 manufactured by JASCO Corporation in the range of 320 to 800 nm to compare the transmittance.

The present invention will be specifically described below based on examples, but these do not limit the present invention in any way. In the formulations of Examples, "parts" and "%" indicate "parts by weight" and "% by weight" unless otherwise specified.

[0137]

【Example】

(Synthesis Example 1) _n C ₄ H ₉ —Si (OCH ₃ ) ₃ was prepared by mixing and stirring the hydrophilic titanium oxide fine particles produced in an aqueous system.
Is added and mixed so that the particles do not coalesce to 30% by weight with respect to the titanium oxide fine particles, dried and crushed, the hydrophobicity is 70%, the average particle size is 0.05 μm, and the transmittance at 400 nm is 55. % Titanium oxide I was obtained.

Synthesis Example 2 In Synthesis Example 1, _n C ₈ H
Hydrophobicity is 60%, average particle size is 0.05 μm, and 4 is the same except that 20% by weight of _17- Si (OCH ₃ ) ₃ is used.
Titanium oxide II having a transmittance of 50% at 00 nm was obtained.

Example 1 100 parts by weight of polyester resin obtained by condensing propoxylated bisphenol and fumaric acid 4 parts by weight of phthalocyanine pigment 2 parts by weight of chromium complex salt of di-tert-butylsalicylic acid

Was sufficiently premixed with a Henschel mixer, melt-kneaded with a twin-screw extruder, cooled, roughly crushed to about 1 to 2 mm with a hammer mill, and then finely crushed with an air jet pulverizer. Crushed. Further, the obtained finely pulverized product was classified by a multi-division classifier to select 2 to 10 μm so as to obtain the particle size distribution of the present invention, to obtain colorant-containing resin particles (toner particles).

1.0% of the titanium oxide fine particles I of Synthesis Example 1 and a weight average particle diameter of 1.9 μm were added to the colorant-containing resin particles.
0.4% zerium oxide, and a weight average particle size of 0.0
Cyan toner was obtained by combining 0.3% of organic resin particles 1 (charge amount +55 μc / g) having a size of 65 μm and having two peaks at 0.05 μm and 0.8 μm.

In this toner, (A) :( B) was 3.33: 1 and (A) :( C) was 2.5: 1.

The weight average particle diameter of this toner is 8.4 μm.
(30% toner by 5 μm or less).

A Cu-Zn-Fe surface-coated with a styrene-butyl methacrylic acid copolymer was added to the cyan toner.
Ferrite particles were added to prepare a developer 1 with a toner concentration of 5%.

The developer 1 and the drum surface roughness 0.3 μm
A commercially available color copying machine (CLC500 manufactured by Canon Inc.) using a photosensitive drum (latent image carrier) having a protective layer formed on its surface and a urethane resin cleaning member whose surface is not covered with a coat layer. ).

The developing conditions are temperature / humidity of 20 ° C./10%.
RH, 23 ° C./65% RH and 30 ° C./80% RH both have a development contrast of 320 V and an image area ratio of 50%
20,000 sheets were prepared using each of the originals.

As a result, no cleaning defect occurred at all, the image density was 1.4 to 1.6, which was very stable, and a very clear image was obtained with no greasiness. Further, when observed on the drum, no deposit was observed.

Example 2 Developer 2 was prepared in the same manner as in Example 1 except that 0.3% of strontium titanate having a weight average particle diameter of 1.3 μm was used in place of cerium oxide. When it was created and imaged in the same manner, good results were obtained.

In this toner, (A) :( B) was 3.33: 1 and (A) :( C) was 3.33: 1.

Example 3 In Example 1, the organic resin particles 1 were replaced by organic resin particles 2 having one peak at a weight average particle diameter of 0.15 μm.
Developer 3 was prepared in the same manner as in Example 1 except that 0.5% was used, and image formation was carried out in the same manner. Good results were obtained.

In this toner, (A) :( B) was 2: 1 and (A) :( C) was 2.5: 1.

Example 4 A developer 4 was prepared in the same manner as in Example 1 except that 1.0% of titanium oxide fine particles II was used in place of the titanium oxide fine particles I, and images were similarly formed. Then, good results were obtained.

In this toner, (A) :( B) was 3.33: 1 and (A) :( C) was 2.5: 1.

Comparative Example 1 A comparative developer 1 was prepared in the same manner as in Example 1 except that cerium oxide was not used, and image formation was carried out in the same manner. ℃ / 10%
Under RH, image defects (filming) were observed in the solid blue part, which consumes a lot of toner, from around 10,000 sheets. Then, when the drum was observed, adhering substances were recognized.

In this toner, (A) :( B) was 3.33: 1 and (A) :( C) was 1: 0.

COMPARATIVE EXAMPLE 2 In Comparative Example 1, when an original having an image area ratio of 20% was used and the toner consumption was reduced, the temperature was 20 ° C./10.
%, Filming of 20,000 sheets was not recognized on the image.
Then, when observing on the drum, adhering substances were slightly observed on the drum.

Comparative Example 3 A comparative developer 2 was prepared in the same manner as in Example 1 except that the organic resin particles 1 were not used, and image formation was carried out in the same manner. Temperature / humidity is 2
At 0 ° C./10% RH or less, toner scattering occurred from about 5,000 sheets. This is because the rise of charging of the replenishment toner is
It is considered that it was delayed because there was no organic resin particle 1.

In this toner, (A) :( B) was 1: 0 and (A) :( C) was 2.5: 1.

Comparative Example 4 A comparative developer 3 was prepared in the same manner as in Example 1 except that the titanium oxide fine particles I were not used. The image density was as low as 1.21 at a temperature / humidity of 23 ° C./65% RH, and only an image with a lot of roughness was obtained.

In this toner, (A) :( B) was 0.03 and (A) :( C) was 0: 0.4.

Comparative Example 5 A comparative developer 4 was prepared in the same manner as in Example 1 except that 0.4% of cerium oxide having a weight average particle diameter of 0.3 μm was used. When images were printed in the same manner, image unevenness was observed in the halftone portion under a temperature / humidity of 23 ° C./65% RH. Then, when the drum was observed, cerium oxide that had slipped through the cleaning blade was observed.

In this toner, (A) :( B) was 3.33: 1 and (A) :( C) was 2.5: 1.

Comparative Example 6 A comparative developer 5 was prepared in the same manner as in Example 1 except that 0.4% of cerium oxide having a weight average particle diameter of 3 μm was used. When the image was printed with, the edge portion of the cleaning blade was scratched and defective cleaning occurred.

In this toner, (A) :( B) was 3.33: 1 and (A) :( C) was 2.5: 1.

Comparative Example 7 A comparative developer 6 was prepared in the same manner as in Example 1 except that 1.2% of cerium oxide was used, and image formation was carried out in the same manner. However, when the temperature / humidity was 20 ° C./10% RH, toner scattering occurred from about 3000 sheets.

In this toner, (A) :( B) was 3.33: 1 and (A) :( C) was 0.83: 1.

Example 5 In the same colorant-containing resin particles (toner particles) as in Example 1,
The titanium oxide fine particles I of Synthesis Example 1 were 1.0%, and the weight average particle diameter was 0.065 μm.
Organic resin particles 1 having two peaks at μm (charge amount +
(55 μc / g) to give 0.3% of cyan toner.

In this toner, (A) :( B) was 3.33: 1.

The weight average particle diameter of this toner is 8.4 μm.
(30% toner by 5 μm or less).

To this toner, Cu-Zn-Fe ferrite particles surface-coated with a methyl methacrylate-butyl methacrylate copolymer (70:30) were added to prepare a developer 5 with a toner concentration of 5%.

Using this developer 5, a cleaning blade of a commercially available color copying machine (manufactured by CLC500 Canon) using a photosensitive drum in which a protective layer is not formed on the surface of the photosensitive layer is used. The polyamide resin containing 10 parts by weight of silicon resin fine particles having a weight average particle diameter of 1.0 μm as shown in FIG. I went.

The development conditions are temperature / humidity of 20 ° C./10%.
RH, 23 ° C./65% RH and 30 ° C./80% RH both have a development contrast of 320 V and an image area ratio of 50%
20,000 sheets were prepared using each of the originals.

As a result, no cleaning failure occurred at all, the image density was 1.4 to 1.6, which was very stable, and a very clear image free from any roughness was obtained. Further, when observed on the drum, no deposit was observed.

Example 6 A cleaning blade was used in the same manner as in Example 5 except that 10 parts by weight of carbon fluoride fine powder having an average particle size of 0.8 μm was used in place of the silicone resin particles. When it was remodeled and an image was printed using the developer 5, good results were obtained.

Example 7 In Example 5, instead of the organic resin particles 1, the organic resin particles 2 having one peak at a weight average particle diameter of 0.15 μm.
Developer 6 was prepared in the same manner as in Example 5 except that 0.3% was used, and image formation was carried out in the same manner. As a result, the temperature / humidity was 20 ° C./10% RH. The image density was 1.35 to 1.45, which was slightly lower than that of Example 5, but good results were obtained.

In this toner, (A) :( B) was 3.33: 1.

Example 8 A developer 7 was prepared in the same manner as in Example 5 except that the titanium oxide fine particles I were replaced by the titanium oxide fine particles II 1.0%. When images were printed, good results were obtained.

In this toner, (A) :( B) is
It was 3.33: 1.

Comparative Example 8 Image development was carried out using the developer 5 in the same manner as in Example 5 except that the cleaning blade in Example 5 in which the surface of the cleaning blade was not coated with the polyamide resin coating layer was used. However, the temperature / humidity is 20 ° C / 10
An image defect (filming) in which a solid blue portion consuming a large amount of toner under 100% RH disappears from around 10,000 sheets was recognized. Then, when the drum was observed, adhering substances were recognized.

COMPARATIVE EXAMPLE 9 In Comparative Example 8, a document having an image area ratio of 20% was used to reduce the toner consumption, and the result was 20 ° C./10.
No filming of 20,000 sheets was observed on the image under% RH. Then, when observing on the drum, adhering substances were slightly observed on the drum.

Comparative Example 10 A comparative developer 7 was prepared in the same manner as in Example 5 except that the organic resin particles 1 were not used, and image formation was carried out in the same manner. Temperature / humidity is 2
Toner scattering occurred from about 5,000 sheets under 0 ° C./10% RH. It is considered that this is because the charging of the replenishment toner was delayed in rising due to the absence of the organic resin particles.

In this toner, (A) :( B) was 1: 0.

Comparative Example 11 A comparative developer 8 was prepared in the same manner as in Example 5 except that the titanium oxide fine particles I were not used, and an image was similarly formed. The image density was as low as 1.21 at a temperature / humidity of 23 ° C./65% RH, and only an image with a lot of roughness was obtained.

In this toner, (A) :( B) was 0: 0.3.

Comparative Example 12 Developer 5 was used in the same manner as in Example 5 except that a cleaning blade coated with a polyamide resin coating layer containing no silicon resin particles was used as the cleaning blade. When images were printed, the temperature / humidity was 30 ° C./80% RH, and the pressure contact between the photoconductor and the cleaning blade was too strong, resulting in image unevenness.

Comparative Example 13 A cleaning blade was coated with a polyamide resin coating layer in the same manner as in Example 5 except that silicon resin fine particles having a weight average particle diameter of 0.10 μm were used as the cleaning blade. Similarly, when an image was formed using the developer 5, the temperature / humidity was 30 ° C./8.
At 0% RH, it was good at the beginning, but from about 2000 sheets, a strange sound which seems to be a rubbing noise between the photoconductor and the cleaning blade was generated. Then, when the edge portion of the cleaning blade was observed, many defects which were considered to be missing the silicon resin fine particles were recognized.

(Production Example 1 of latent image bearing member) Nylon (M-
(4000: manufactured by Toray) 10 parts by weight, 100 parts by weight of methanol and 90 parts by weight of isopropanol are mixed and dissolved, and then dip-coated on an aluminum cylinder 21 having an outer diameter of 80 mm, a wall thickness of 1.5 mm, and a length of 363 mm, 90 ℃
And dried for 20 minutes to obtain a 2.0 μm undercoat layer 22.

Next, the following structural formula

[0189]

[Outside 2] 10 parts by weight of the triazo pigment represented by 5 parts by weight, 5 parts by weight of a polycarbonate resin (bisphenol A type, Mn = 20,000) and 600 parts by weight of cyclohexanone were dispersed in a sand mill to obtain a charge generation layer coating material. This paint was applied onto the undercoat layer 22 by dip coating and dried at 120 ° C. for 20 minutes to obtain a charge generation layer 23a having a thickness of 0.15 μm.

The following structural formula

[0191]

[Outside 3] 20 parts by weight of the biphenyl compound represented by the formula, polycarbonate resin (bisphenol A type: Mn = 20,000)
20 parts by weight, 2 parts by weight of polytetrafluoroethylene fine particles (Lupron L-5: manufactured by Daikin Industries, Ltd.) and 800 parts by weight of monochlorobenzene were dispersed in a ball mill to obtain a charge transport layer coating material. This paint is applied to the charge generation layer 2
Dip-coat on 3a, dry at 130 ° C for 90 minutes and
A μm charge transport layer 23b was formed.

Next, 2 parts by weight of polytetrafluoroethylene fine particles (Lupron L-5: manufactured by Daikin Industries, Ltd.),
6 parts by weight of the biphenyl compound, 12 parts by weight of a polycarbonate resin (bisphenol Z type: Mn = 80,000) and 1000 parts by weight of dichloromethane were dispersed in a sand mill to obtain a protective layer coating material. This coating material was spray-coated on the charge transport layer 23b and dried at 120 ° C. for 30 minutes to form a protective layer 24 having a thickness of 6.0 μm.

Further, the latent image bearing member produced by the above method had surface average surface roughnesses of 0.3 μm, 1.0 μm,
The latent image carrier A (0.3 μm) was mechanically polished in advance with a wrapping tape (C-2000, manufactured by Fuji Photo Film Co., Ltd.) so as to have a size of 3.5 μm.
m), latent image carrier B (1.0 μm) and latent image carrier C
(3.5 μm), respectively.

(Manufacturing Example 2 of Latent Image Bearing Member) A latent image carrying member D is manufactured in the same manner as in Manufacturing Example 1 except that the protective layer is not provided and mechanical polishing is not carried out. Was produced. The average surface roughness of the latent image carrier D is 0.2 μm.
Met.

Example 9 The same colorant-containing resin particles (toner particles) as in Example 1 were mixed with 1.0% of titanium oxide I of Synthesis Example 1 and a weight average particle diameter of 1.9.
0.5% cerium oxide, and an organic resin particle 1 having a weight average particle diameter of 0.065 μm and two peaks of 0.05 μm and 0.8 μm (charge amount +55 μc /
g) 0.3% and the weight average particle diameter is 8.4 μm (5 μ
Cyan toner in which the toner of m or less is 30% by number) was used.

In this toner, (A) :( B) was 3.33: 1 and (A) :( C) was 2: 1.

Cu-Zn-Fe type ferrite particles whose surface was coated with a styrene-butyl methacrylate copolymer were added to the cyan toner to prepare a developer 8 with a toner concentration of 5%. This developer 8 and the surface roughness 1.
A 0 μm latent image carrier B is used as a commercially available color copying machine (CLC5
(Canon Co., Ltd.) was used to evaluate the image output.

In the image evaluation, the development contrast was 300 V, and the temperature / humidity was 20 ° C./10% RH, 2
An endurance test was performed on 40,000 sheets each using a document having an image area ratio of 50% in three environments of 3 ° C./65% RH and 30 ° C./80 RH.

As a result, in the present invention, due to the improvement of the latent image carrier and the developer, no defective cleaning occurs even after 40,000 sheets have been used, and the image density is 1.4 to 1.6.
The image was stable, and an image similar to the initial one was obtained in terms of fog and sharpness.

Example 10 Developer 9 was prepared in the same manner as in Example 9 except that 0.5% of strontium titanate having a weight average particle diameter of 1.5 μm was used in place of cerium oxide. When images were printed in the same manner, good results were obtained.

In this toner, (A) :( B) is 3.
33: 1 and (A) :( C) were 2: 1.

Example 11 In Example 9, the surface roughness shown in Production Example 1 was 0.3 μm.
Image formation was carried out using the developer 8 in the same manner as in Example 9 except that the latent image carrier A was used, and good results were obtained.

Example 12 A developer 10 is prepared in the same manner as in Example 9 except that the titanium oxide fine particles I in Example 9 are replaced by 1.0% of the titanium oxide fine particles II in Synthesis Example 2. Then, when images were printed out in the same manner, good results were obtained.

In this toner, (A) :( B) is 3.
33: 1 and (A) :( C) were 2: 1.

Comparative Example 14 A comparative developer 10 was prepared in the same manner as in Example 9 except that cerium oxide was not used, and images were similarly formed. Humidity is 20 ° C /
10% RH), 2000 in the relatively high consumption image area
Filming was recognized from the sheet position, and when the latent image bearing member was observed there, adhering substances were confirmed.

In this toner, (A) :( B) is 3
The ratio of 3.1: 1 and (A) :( C) was 1: 0.

Comparative Example 15 In Example 9, image formation was performed using the developer 8 in the same manner as in Example 9 except that the latent image carrier D shown in Production Example 2 was used. Image unevenness occurred in the halftone area from around 10,000 sheets. Then, when the latent image bearing member was examined, unevenness was recognized in the scraping condition.

Comparative Example 16 In Example 9, the surface roughness shown in Production Example 1 was 3.5 μ.
Image formation was performed using the developer 8 in the same manner as in Example 9 except that the latent image carrier C of m was used, and only an image inferior in highlight reproduction of the photographic original was obtained. .

Example 13 Polytetrafluoroethylene fine particles (Lupron L-5: used for forming the protective layer in Production Example 1 of latent image bearing member).
The average surface roughness of the flat surface is 0.3 μm in the same manner, except that the amount of Daikin Industries, Ltd.) is changed to 6 parts by weight.
A latent image carrier E of m was prepared.

A cleaning blade of a commercially available color copying machine (CLC500 Canon) was used in Example 6,
Replace with a cleaning blade whose surface is coated with a polyamide resin coating layer containing carbon fluoride fine powder,
Further, the latent image bearing member was replaced with the above latent image bearing member 5, and the developer 8 used in Example 9 was used as the developing agent for image evaluation.

In image evaluation, the development contrast was 300 V, and the temperature / humidity was 20 ° C./10% RH and 2
An endurance test was performed on 50,000 sheets using a document having an image area ratio of 50% in three environments of 3 ° C./65% RH and 30 ° C./80% RH.

As a result, in the present invention, due to the improvement of the latent image carrier and the developer, no defective cleaning occurs even after the endurance of 50,000 sheets and the image density is 1.4 to 1.6.
The image was stable, and an image similar to the initial one was obtained in terms of fog and sharpness.

[0213]

As described above, according to the toner or the image forming method of the present invention, the durability of the latent image carrier can be improved, and the cleaning failure and the image defect can be prevented, and the fine line reproducibility and the highlight level can be improved. It has become possible to obtain images with excellent tonality.

[Brief description of drawings]

FIG. 1 shows a cross-sectional view of a cleaning member used in the present invention.

FIG. 2 is a schematic view schematically showing a cleaning state in which a cleaning member is in contact with the surface of a latent image carrier in the image forming method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cleaning member 2 Latent image carrier 11 Blade support 12 Base material 13 Polyamide resin coat layer 21 Conductive support 22 Undercoat layer 23 Photosensitive layer 23a Charge generation layer 23b Charge transport layer 24 Protective layer

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Toshiyuki Ukai 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yasuhiro Ichikawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Within the corporation

Claims (13)

[Claims] 1. A toner for developing an electrostatic charge image, comprising toner particles and an external additive, wherein the external additive has a hydrophobized titanium oxide particle having a weight average particle diameter of at least 0.01 to 0.2 μm. (A), having an organic resin particle (B) having a weight average particle diameter of 0.02 to 0.5 μm and an inorganic compound (C) having a weight average particle diameter of 0.5 to 2.5 μm, The external additive satisfies the following relationship (A) :( B) = 2: 1 to 10: 1 (A) :( C) = 1: 1 to 5: 1, and the toner has a particle size of 2 A toner for developing an electrostatic charge image, comprising 15 to 40% by number of toner particles having a particle size of 5 μm. 2. The electrostatic image developing toner according to claim 1, wherein the titanium oxide particles (A) are subjected to a hydrophobic treatment in an aqueous system. 3. The titanium oxide particles (A) are hydrophobized in an aqueous system, and the external additive has the following relationship (A) :( B) = 2: 1 to 10: 1 (A): The toner for developing an electrostatic charge image according to claim 1, wherein (C) = 2: 1 to 5: 1 is satisfied. Wherein the titanium oxide particles (A), silane coupling represented by the following general formula _{C n H 2n + 1 -Si- (} OC m H 2m + 1) 3 n = 4~12 m = 1~3 It is processed by hydrolyzing the ring agent in a water system, and the weight average particle diameter is 0.01 to 0.2.
4. The toner for developing an electrostatic charge image according to claim 1, wherein the toner has a hydrophobicity of 40 μm and a hydrophobicity of 40 to 80% and a light transmittance of 400% or more at 400 μm. 5. (i) A developed image is formed on the surface of a latent image carrier containing an organic photoconductive substance with toner, and (i)
i) transferring the developed image to a transfer material, and (iii) transferring the image,
Cleaning the latent image carrier with a cleaning member,
(Iv) In an image forming method in which the latent image carrier after cleaning is repeatedly used, the toner contains toner particles and an external additive, and the external additive is at least 0.01 to 0.2 μm. Of the titanium oxide particles (A) that have been subjected to a hydrophobization treatment and that have a weight average particle diameter of 0.02 to 0.5 μm, and the organic resin particles (B) have a weight average particle diameter of 0.02 to 0.5 μm. The following relationship (A) :( B) = 2: 1 to 10: 1 is satisfied, and the toner contains 15 to 40% by number of toner particles having a particle diameter of 2 to 5 μm. An image forming method comprising: a resin base material; and a polyamide resin coat layer containing a low surface free energy fine particle having a weight average particle diameter of 0.15 to 2.0 μm coated on the resin base material. 6. The image forming method according to claim 5, wherein the titanium oxide particles (A) are subjected to a hydrophobic treatment in an aqueous system. 7. The image forming method according to claim 5, wherein the low surface free energy fine particles are a fluorine-based resin powder or a silicon-containing compound. 8. The image forming method according to claim 7, wherein the silicon-containing compound is a silicone resin particle. 9. (i) A developed image is formed with toner on the surface of a latent image carrier containing an organic photoconductive substance, and (i)
i) transferring the developed image to a transfer material, and (iii) transferring the image,
Cleaning the latent image carrier with a cleaning member,
(Iv) In an image forming method in which the latent image carrier after cleaning is repeatedly used, the toner contains toner particles and an external additive, and the external additive is at least 0.01 to 0.2 μm. Hydrophobized titanium oxide particles (A) having a weight average particle diameter of
The organic additive particles (B) having a weight average particle diameter of 0.02 to 0.5 μm and the inorganic compound (C) having a weight average particle diameter of 0.5 to 2.5 μm are included, and the external additive Satisfy the following relationship (A) :( B) = 2: 1 to 10: 1 (A) :( C) = 1: 1 to 5: 1, and the toner is toner particles having a particle diameter of 2 to 5 μm. The latent image carrier has a photosensitive layer containing an organic photoconductive substance and a protective layer formed on the surface side of the photosensitive layer.
The image forming method, wherein the protective layer contains fluorine atom-containing resin particles in an amount of 5 to 40% by weight based on the total weight of the protective layer. 10. The image forming method according to claim 9, wherein the titanium oxide particles (A) are subjected to a hydrophobic treatment in an aqueous system. 11. The titanium oxide particles (A) are hydrophobized in an aqueous system, and the external additive has the following relationship (A) :( B) = 2: 1 to 10: 1 (A). The image forming method according to claim 9 or 10, wherein: (C) = 2: 1 to 5: 1 is satisfied. 12. The surface of the latent image carrier is 0.1 to 2.5.
The image forming method according to claim 9, which has an average surface roughness (Rz) of 10 μm. 13. The surface of the latent image carrier is 0.1 to 1.
The image forming method according to claim 9, which has a 10-point average surface roughness (Rz) of 5 μm.