JPS63155151A - Electrostatic developer and electrostatic developing method and image forming method - Google Patents

Abstract

PURPOSE:To obtain good positive electrostatic chargeability and excellent moisture resistance by incorporating fine inorg. particles of which the surfaces are treated by an amino compd. and silicone compd. into a titled developer. CONSTITUTION:The fine inorg. particles of which the surfaces are coated by the amino compd. and silicone compd. are incorporated into the electrostatic developer. More specifically, the surfaces of the fine inorg. particles are treated by the amino group and silicone compd., by which the amino compd. and silicone compd. are bonded respectively to the negative electrostatically chargeable site and hydrophilic site of the fine inorg. particles and securely held to said surfaces. As a result, a hydrophobic property is imparted to the fine inorg. particles by the silicone compd. and the positive electrostatic chargeability is imparted to the fine inorg. particles by the amino compd. The developer which stably exhibits the positive electrostatic chargeability by the fine inorg. particles even under high humidity environmental conditions and has the excellent positive electrostatic chargeability is thus obtd.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an electrostatic image used for developing an electrostatic latent image formed in electrophotography, electrostatic recording, electrostatic printing, etc. A developer, an electrostatic image developing method for developing an electrostatic latent image formed on the surface of a photoreceptor made of an organic photoconductive semiconductor using this electrostatic image developer, and developing these electrostatic images This invention relates to an image forming method for forming an image using a photoreceptor and an electrostatic image developing method, and is particularly used when developing a negative electrostatic 74-layer image formed on the surface of a photoreceptor made of an organic photoconductive semiconductor. The present invention relates to a suitable electrostatic image developer, an electrostatic image developing method, and an image forming method.

[Background of the invention]

Generally, in electrophotography, a photoreceptor having a photosensitive layer made of a photoconductive material is given a uniform electrostatic charge, and then an electrostatic latent image is formed on the surface of the photoreceptor by performing image exposure. This electrostatic latent image is developed with a developer to form a toner image. The obtained toner image is transferred to a transfer material such as paper and then fixed by heating or pressure to form a copy image.

Examples of the photoconductive material used to form the photosensitive layer of the photoreceptor include inorganic photoconductive materials such as selenium, zinc oxide, and cadmium sulfide, and organic photoconductive materials made of high molecular compounds or low molecular weight compounds such as polyvinyl carbazole. There are known materials such as carbonaceous materials.

However, although photoreceptors having photosensitive layers formed from these photoconductive materials have one advantage in forming electrostatic latent images, they also have drawbacks specific to various photoreceptors. have.

For example, in a photoreceptor having a photosensitive layer formed of selenium, the photosensitive layer easily crystallizes due to heat or metal compounds contained in the developer or transfer material, deteriorating its properties, resulting in an electrostatic latent image. There is a problem that the potential of the image decreases, resulting in a decrease in image density or partial image blanking. In addition, under high-temperature environmental conditions, the photoconductivity of the photosensitive layer decreases and static charges remain in the non-image areas of the photoreceptor, resulting in fogging and making it difficult to obtain clear images. However, under high humidity environmental conditions, good images cannot be formed many times and durability is low.

Additionally, photoreceptors having a photosensitive layer formed of cadmium sulfide or a photoreceptor having a photosensitive layer formed of zinc oxide typically have a photoconductive material, ie, cadmium sulfide or zinc oxide, dispersed in a binder resin. A photosensitive layer is formed, but it is quite difficult to uniformly disperse such a photoconductive material in the form of fine particles in a binder resin, and as a result, the resulting photoreceptor has low sensitivity and is unsuitable for high-speed copying. In addition, the photosensitive layer tends to deteriorate early in the corona charging process or exposure process that is normally used to form an electrostatic latent image, making it difficult to form a good image over a long period of time. Furthermore, under high-temperature environmental conditions, the characteristics of the photosensitive layer change due to moisture, making it impossible to obtain the desired potential of the electrostatic latent image, resulting in a low image quality. There is.

On the other hand, the W1 photoreceptor, which has a photosensitive layer formed from a polymeric photoconductive material typified by polyvinylcarbazole, has good film formability and can be manufactured at low cost. It also has the advantage of not being toxic to the human body, and has attracted attention in recent years. However, on the other hand, it has low sensitivity and tends to deteriorate early during the corona charging process or exposure process, resulting in poor durability. Since the sensitivity or Ti charge retention ability tends to change, it is still inferior to a photoreceptor having a photosensitive layer made of an inorganic photoconductive material, and the development of a high-performance photo-RN material is desired.

On the other hand, in order to overcome the above problems, it has recently been proposed to use low molecular weight organic photoconductive materials. Since the low molecular weight organic photoconductive material has good dispersibility in the binder resin, the resulting photosensitive layer has the organic photoconductive material uniformly dispersed in the form of fine particles. It is possible to obtain a photoreceptor with relatively high sensitivity, and by forming the photoreceptor layer by dispersing an organic photoconductive material in a binder resin, film forming properties are good, so the photoreceptor can be manufactured with high productivity. There are many types of low-molecular-weight photoconductive materials that can be manufactured and used, and therefore, by using appropriately selected low-molecular-weight photoconductive materials, a photoreceptor having better performance than conventional ones can be obtained. Is possible. Thus, an organic photoreceptor having a photosensitive layer formed of a low molecular weight organic photoconductive material is more preferable than conventional photoreceptors.

However, since organic photoconducting materials usually exhibit photoconductivity through the movement of positive charges, the surface of an organic photoreceptor containing a photosensitive layer formed of the organic photoconductive material is The polarity of the electrostatic latent image to be formed is preferably negative. In order to develop a negative electrostatic layer image, it is necessary to use a developer containing a positively charged toner.

However, in the conventionally widely used photoreceptor having a photosensitive layer made of selenium, etc., the polarity of the electrostatic latent image formed on the surface is positive, so it is difficult to develop the electrostatic latent image. Developers containing negatively charged toner are used, and considerable research and development efforts have been made on developing agents containing negatively charged toner. Research and development of developers containing toner is still lagging behind, and the reality is that a developer containing a sufficiently positively charged toner has not been obtained.

On the other hand, wet developing methods and dry developing methods are known as methods for developing electrostatic latent images. The former wet development method is
Since a liquid developer is used, there is a problem in that it emits a bad odor, and there is also a problem in that high-speed copying is difficult because high energy is required to dry the transfer material. The latter dry developing method does not have such problems and can be preferably used as a developing method for static TL latent images.

The developers used in the dry development method include a so-called one-component developer consisting only of a magnetic toner containing a magnetic substance, and a so-called two-component developer consisting of a non-magnetic toner that does not contain a magnetic substance and a magnetic carrier. type developer is known.

The former one-component developer consists only of magnetic toner and does not have a carrier, so there is some frictional electrification caused by the toners and the height of the toner and the developing sleeve or developer layer placed in the developing device is controlled. The toner is charged by frictional charging with the regulating blade, etc., and as a result, both positively charged toner and negatively charged toner exist, and since the frictional band 1ii1 is small, development is basically unstable. There are some problems that can easily become a problem. Specifically, for example, toner may adhere to non-image areas on the photoreceptor, causing fog in the final fixed image, or the amount of toner adhering to the image area on the photoreceptor may be insufficient, resulting in Fixed image? ;There is a problem that the degree is low.

In addition, the magnetic material used in magnetic toner usually has hydrophilic properties, and since this hydrophilic magnetic material is often contained in an exposed state on the surface of toner particles, the toner becomes triboelectrically charged due to moisture. Charge tends to leak, and in high-temperature environments, electrostatic transfer to the transfer paper normally used as a transfer material becomes defective during the transfer process, resulting in a low toner transfer rate to the transfer paper. There are problems in that the density of the final fixed image decreases and image blanking occurs. In addition, since the magnetic material used in magnetic toner usually has negative chargeability, it is difficult to positively charge the magnetic toner with an appropriate amount of charge, and as a result, a large proportion of toner with the opposite polarity exists. There are problems in that the density of the final fixed image decreases, and image unevenness and image missing occur.

On the other hand, the latter two-component developer is composed of toner and carrier, and the carrier has the function of charging the toner to a desired polarity. It is possible to impart a triboelectric charge depending on the amount, and it is possible to obtain a developer having much superior triboelectric chargeability compared to the one-component developer described above.

Further, by selecting a carrier having desired characteristics, it is possible to control the amount of charge of the toner to a considerable extent.

However, in order to obtain a good final fixed image, it is not enough that the developer has good triboelectric chargeability, and particles of the developer to which triboelectric charge has been applied do not aggregate in the developing device. It is necessary that the film be transported to the developing space in good condition without any damage.

For example, in the magnetic brush development method, a developer that has been given a triboelectric charge by being stirred in a developing device is supported on the developing sleeve in the form of a thin layer arranged in a uniform brush shape. It is necessary for the developer layer having the same shape to be stably transported to the development space while retaining its shape.

For example, in a one-component developer, since it consists only of magnetic toner and does not have a carrier, the 1Hfi toner is
The magnetic cohesive force and electrostatic cohesive force are strong, and as a result, the magnetic toner coagulates and forms clumps, reducing the fluidity of the developer. As a result, the magnetic toner is uniformly arranged on the developing sleeve in a thin, brush-like manner. There is a problem in that it is difficult to support the material in a fan-like shape. In addition, since the magnetic toner tends to form agglomerates, frictional electrification between the magnetic toners or between the magnetic toner and the wall, regulating blade, developing sleeve, etc. inside the developing device is not achieved properly. As a result, there is a problem that the final fixed image becomes unclear with a lot of fog.

In addition, for example, in a two-component developer, if the toner tends to aggregate and form clumps due to electrostatic cohesive force, it becomes difficult to disperse the toner particles in the carrier particles at a uniform concentration. As a result, the triboelectricity between the toner and the carrier decreases, and the proportion of toner with low triboelectricity increases.In the developing process, toner adheres to non-image areas on the photoreceptor, causing fog in the final fixed image. ,
In addition, there is a large amount of weakly charged toner (the electrostatic adhesion force between the toner and the carrier is small). Therefore, in the magnetic brush development method, toner particles adhere to the carrier particles while rotating the carrier particles by magnetic force. When conveying to the developing space, the toner particles scatter due to the centrifugal force caused by the rotation of the carrier particles, which contaminates the charger, exposure optical system, and other equipment installed in the copying machine, causing the final There is a problem in that image defects such as image unevenness and image missing occur in the fixed image.

However, in conventional negatively charged toners, fine silica particles having a smaller diameter than the toner particles are mixed with the toner particles to attach the fine silica particles to the surface of the toner particles, thereby preventing the toner from clumping. This is done to obtain high liquidity.

However, conventionally used silica fine particles have strong negative chargeability, so when obtaining a positively chargeable toner, if silica fine particles are mixed with the toner and attached to the surface of the toner particles, the resulting toner will be negatively charged. It becomes electrostatic,
As a result, the polarity becomes the same as the negative electrostatic latent image formed on the photoreceptor, and there is a problem that electrostatic development cannot be performed.

The following techniques have been disclosed as techniques for solving such problems.

(1) A technique using positively charged fine particles treated with a silane coupling agent (see JP-A-53-66235, JP-A-56-123550, and JP-B-Sho 53-22447).

(2) Technology using positively charged fine particles treated with silicone oil (JP-A-58-60754, JP-A-58-59)
(Refer to Publication No.-187359).

[Problem that the invention seeks to solve]

However, as in techniques (1) and (2) above, positively charged fine particles treated with a silane coupling agent or silicone oil are used, mixed with the toner, and attached to the surface of the toner particles. However, when subjected to physical force such as stirring in the developing device, the fine particles become scattered from the surface of the toner particles, and as a result, the toner is not positively tribo-electrified with an appropriate amount of charge, and it also scatters. Fine particles become physically or electrostatically attached to the inner wall of the developing device, the developing sleeve disposed inside the developing device, the regulating blade, the surface of carrier particles, etc., and the triboelectric charging properties of the toner are inhibited. If the accumulation due to adhesion becomes excessive, the fine particles and toner particles will be triboelectrically charged, and the toner particles will become oppositely charged, that is, negatively charged, resulting in the toner scattering and contaminating the inside of the device. In the final fixed image, there are problems such as fogging and a decrease in image density, resulting in an unclear image. Further, when image formation is repeated many times, the image gradually becomes less clear, resulting in a defective image at an early stage, resulting in low durability.

In particular, when using fine particles treated with a silane coupling agent, it is difficult to completely cover the surface of the fine particles with the silane coupling agent, and as a result, the negatively charged sites and woody sites of the fine particles are The positive charging ability of the toner decreases due to the remaining negatively charging sites,
Furthermore, the toner becomes negatively chargeable, resulting in a lot of fogging in the final fixed image, and due to the remaining parent-like sites, it becomes susceptible to the effects of humidity, so when environmental conditions change, triboelectric charging becomes less becomes unstable,
As a result, the inside of the device becomes contaminated due to toner scattering, fog occurs in the final fixed image, image density decreases due to a decrease in transfer rate in the transfer process, and image unevenness occurs due to toner scattering. , there is a problem that the image becomes unclear.

In addition, especially when using fine particles treated with silicone oil, the surface of the fine particles is covered with a sticky oily substance, so such fine particles are mixed with the toner to coat the surface of the toner particles. It is difficult to improve the fluidity of the toner even if it is attached to the toner, physical aggregation may occur due to silicone oil, and fine particles may adhere to the inner wall of the developing device, the developing sleeve, the regulating blade, etc. The problem is that the positive charging ability of the toner is reduced, the resulting image quality is reduced, and contamination due to toner scattering occurs, resulting in the final fixed image being unclear with a lot of fog and image gaps. be.

In addition, in the image forming process, the toner image formed on the surface of the photoreceptor through the development process is subjected to a transfer process, and in this transfer process, it is transferred to a transfer material made of ordinary paper or the like. As the transfer means, it is preferable to use electrostatic transfer means that utilizes electrostatic force.

However, as in the techniques (1) and (2) above, a toner image formed on the surface of a photoreceptor by being developed with a toner composed of fine particles treated with a silane coupling agent or silicone oil is Due to the insufficient amount of charge and the strong adhesion to the surface of the photoreceptor, it is difficult to transfer it well with some electrostatic transfer means, resulting in uneven images and missing images in the final fixed image. There is a problem that the image density decreases.

Further, the photoconductor after the toner image has been transferred in the transfer process is then subjected to a cleaning process, in which the toner remaining on the surface of the photoconductor after the transfer process is removed, and the surface of the photoconductor is cleaned. Cleaned. However, as in the techniques (1) and (2) above, toners made using fine particles treated with a silane coupling agent or silicone oil are not physically or electrostatically attached to the surface of the photoreceptor. Due to the large adhesion force, it is difficult to completely clean the residual toner, and as a result, some of the toner remains on the photoreceptor and has a negative impact on the next image formation, causing the problem that the image becomes unclear. .

Further, the transfer material to which the toner image has been transferred in the transfer step is subjected to a fixing step, in which the toner image is fixed to the transfer material by being heated or pressurized by a heat roller.
A final fixed image is formed.

However, as in the techniques (1) and (2) above, toner composed of fine particles treated with a silane coupling agent or silicone oil tends to transfer and adhere to the surface of the heated roller. Therefore, a so-called offset phenomenon occurs in which the toner adhering to the heat roller transfers to the next transfer material and stains the image, and when the toner adhering to the heat roller solidifies, this causes the heat roller to There is a problem that the surface is damaged and the durability of the heat roller is significantly reduced.

[Purpose of the invention]

The present invention has been made based on the above-mentioned circumstances, and its objects are: (1) to provide an electrostatic image developer having good positive chargeability and excellent moisture resistance; 2) To provide an electrostatic image developing method capable of satisfactorily developing a negative electrostatic layer image formed on an organic photoconductive photoreceptor without scattering of developer particles; (3) Environmental conditions. To provide an image forming method capable of stably forming an image of good image quality with a high image layer degree and no fog over a large number of times without being affected by the above.

[Means for solving problems]

The electrostatic image developer of the present invention comprises inorganic fine particles (hereinafter referred to as "
It is characterized by containing specific inorganic fine particles j).

The electrostatic image developing method of the present invention includes a negative electrostatic TL latent image formed on the surface of a photoreceptor (hereinafter also referred to as "organic photoreceptor") made of an organic photoconductive semiconductor containing the specific inorganic fine particles. It is characterized by being developed using an electrostatic image developer made of:

The image forming method of the present invention includes a latent image forming step of forming a negative electrostatic latent image on the surface of the organic photoreceptor, and developing the electrostatic latent image containing the specific inorganic fine particles. a development step in which the toner image obtained by development is electrostatically transferred to a transfer material; and a cleaning step in which the developer remaining on the surface of the organic photoreceptor is cleaned with a cleaning blade after the transfer step. and a fixing step of heating and fixing the toner image on the transfer material using a heat roller fixing device having a heat roller coated with a fluororesin or a silicone resin.

[Function and effect of the invention]

Since the electrostatic image developer of the present invention contains specific inorganic fine particles, it has good positive chargeability and excellent moisture resistance. That is, by treating the surface of the inorganic fine particles with an amino compound and a silicone compound, the amino compound and the silicone compound bind to the negatively charged site and the hydrophilic site on the surface of the a-free fine particle, respectively, and bind to the surface. As a result, the silicone compound imparts hydrophobicity to the inorganic particles, and the amino compound imparts positive chargeability to the inorganic particles.Even under high-temperature environmental conditions, the inorganic particles Positive chargeability is stably exhibited, and a developer with excellent positive chargeability can be obtained.

In addition, the specific IR-free fine particles mentioned above have good adhesion to the developer and are firmly held by the developer particles, so that when the developer is stirred in the developing device, No g! Li particles are prevented from transferring and adhering to the inner wall of the developing device, the developing sleeve, the regulating blade, etc., and as a result, the developer exhibits stable positive chargeability even when performing the image forming process multiple times. .

Since the specific inorganic fine particles impart high fluidity to the developer, the developer particles do not aggregate and are triboelectrically charged in a stable state.

According to the electrostatic image developing method of the present invention, in order to develop a negative electrostatic latent image formed on the surface of an organic photoreceptor with an electrostatic image developer containing the above-described specific Ia-free fine particles, It is possible to develop a negative electrostatic latent image formed on the organic photoreceptor well without scattering of developer particles without sacrificing the advantages of the organic photoreceptor such as low production cost and non-toxicity. In other words, since the above-mentioned developer has excellent positive chargeability, it becomes positively charged with an appropriate amount of charge, and therefore, the developer particles are stably held in the developing sleeve. Since the developer particles are transported to the developing space, it is possible to prevent the occurrence of contamination due to scattering of developer particles.

In addition, as mentioned above, the fluidity of the developer is excellent, so it is possible to form a uniform magnetic plan of the developer on the developing sleeve, thus achieving good development using the magnetic brush development method. It becomes possible to do so.

According to the image forming method of the present invention, since the electrostatic image developer contains the above-mentioned specific inorganic fine particles and has excellent positive chargeability, in the developing step, the non-image on the organic photoreceptor is As a result, it is possible to obtain a clear image without fog in the final fixed image. In addition, since the specific inorganic fine particles give the developer suitable releasability, the physical adhesion to the surface of the organic photoreceptor is small. Transfer can be performed, and it is possible to form a clear image with high image quality and no image unevenness. In addition, since the developer has good transferability as mentioned above, only a small amount of developer remains on the organic photoreceptor after the transfer process, and therefore, the remaining developer can be easily cleaned in the cleaning process. Moreover, as mentioned above, the developer has suitable mold release properties, so the adhesion of the developer to the organic photoreceptor is small, making it possible to easily clean the developer using a cleaning blade. becomes.

Furthermore, since the cleaning properties of the developer are good, it is possible to achieve good cleaning even with a small pressure contact force of the cleaning blade against the organic photoreceptor. This prevents premature deterioration of the characteristics of the organic photoreceptor due to wear, and the service life of the organic photoreceptor can be significantly extended. In addition, in the fixing step, since the specific Im-free fine particles are present between the surface of the molten developer and the heat roller, a mold release action by the specific inorganic fine particles is obtained, and the heat roller of the developer This also prevents the developer from accumulating in the minute grooves of the heat roller, and since the heat roller is coated with fluororesin or silicone resin, the developer is prevented from transferring to the heat roller. Transfer adhesion is further prevented, and as a result, image stains caused by offset phenomena can be prevented. In addition, since the surface of the specific =ii particles is covered with an amino compound and a silicone compound,
There is little risk that the surface of the heat roller will be damaged by the fine particles, the service life of the heat roller can be significantly extended, and excellent anti-offset properties can be stably obtained over a long period of time.

[Specific structure of the invention]

The electrostatic image developer of the present invention contains inorganic fine particles whose surfaces have been treated with an amino compound and a silicone compound.

Examples of the amino compounds include diethylenetriamino, dipropylenetriamino, triethylenetetramine, tetraethylenepentamine, dimethylaminopropylamino, diethylaminopropylamino, dibutylaminopropylamino, hexamethylenediamino, N-aminoethylpiperazine, Bis-aminopropylbiperazine, trimethylhexamethylenediamino, bis-(hexamethylene)triamino, ethanolamino, triethanolamino, jetanolamino, cetylpyridinium chloride, butylamino, triethylamino, aniline, pyridine, methylidine tris Aniline, 4.4',
4”-Methyridine tris (N.

Organic primary amino acids such as N dimethylaniline), secondary
Grade aminos, tertiary aminos, salts thereof, etc. can be used. Further, metal complexes containing nitrogen atoms can also be used.

The silicone compound is preferably one that can react with hydrophilic sites or negatively charged sites on the surface of the inorganic fine particles to make the inorganic fine particles hydrophobic. Specifically, for example, silane coupling agents, silicone Oil, silicone oil, silicone rubber, silicone resin, or cured products thereof can be used.

In the present invention, microparticles whose surfaces have been treated with an amino compound and a silicone compound are used. In the surface treatment, the treatment with the amino compound and the treatment with the silicone compound are carried out simultaneously. The treatment may be carried out using a treatment liquid containing both an amino compound and a silicone compound.

By performing the treatment with an amino compound and the treatment with a silicone compound at the same time in this way, the amino compound and the silicone compound are eliminated! The amino compound and the silicone compound are strongly held on the surface of the inorganic fine particle by bonding with the hydrophilic site or the negatively charged site of the a'R1 particle surface, and the presence of the amino compound makes the silicone As a result, the silicone compound imparts hydrophobicity to the non-am particles, and the amino compound imparts positive chargeability to the inorganic fine particles, resulting in the inorganic fine particles becoming impact resistant. It has excellent strength, moisture resistance, and mold releasability.

Examples of inorganic fine particles whose surfaces are treated with the amino compound and silicone compound include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, chromium oxide, and cerium oxide. , antimony dioxide, zirconium oxide, silicon carbide, and the like. Such inorganic fine particles have their primary particles (
The average particle size of particles separated into individual unit particles is
It is preferably within the range of 3lp to 2n.

In particular, silica particles can be preferably used as the GG-free particles. Silica fine particles are Si -0-
They are fine particles having 3t bonds, and may be produced by either a dry method or a wet method, but those produced by a dry method are preferable, and in particular, silica produced by vapor phase oxidation of silicon halogen compounds. Preferably, they are fine particles. In addition to silicon dioxide (silica), the silica fine particles may also be fine particles made of silicates such as aluminum silicate, sodium silicate, calcium silicate, potassium silicate, zinc silicate, and magnesium silicate. However, those containing 85% by weight or more of Sing are preferred.

Known techniques can be used to treat the surface of the inorganic fine particles with the amino compound and silicone compound. Specifically, for example, in a solution in which the amino compound and silicone compound are dissolved in a solvent,
After dispersing the inorganic fine particles, remove the solvent by filtration or spray drying, and then harden by heating, or use a fluidization head device to dissolve the solution of the amino compound and silicone compound in the solvent. A method can be used in which the film is cured by spray coating on fine particles and then heating and drying to remove the solvent.

The particle size of the inorganic fine particles whose surfaces have been treated with the amino compound and silicone compound thus obtained is as follows:
It is preferable that the average particle diameter of the primary particles is within the range of 3 mtr to 2 gm, particularly 51 p to 500 mμ, and the specific surface area by the BET method is 20 to 500 mμ.
Preferably at/g. If the average particle diameter is too small or the specific surface area is too large, the inorganic particles may easily slip through during cleaning using, for example, a blade-type cleaning device, resulting in poor cleaning. On the other hand, when the average particle diameter is too large or the specific surface area is too small, the fluidity of the developer decreases, resulting in poor developability, which may result in a decrease in image density or the occurrence of image unevenness.

When constituting a one-component developer, the specific inorganic fine particles are added to and mixed with the magnetic toner particles from the outside, and are contained in a state where they are attached or implanted onto the surface of the magnetic toner particles. Ru. In addition, in the case of forming a two-component developer, the specific Im-free fine particles are added to and mixed with the non-magnetic toner particles from the outside, so that they are attached or implanted onto the surface of the non-magnetic toner particles. This is further mixed with a carrier.

The content ratio of the specific inorganic fine particles is 0.1 to 0.1 in the toner.
Preferably 5% by weight, especially 0.1-2% by weight
It is preferable that When the content ratio of the specific inorganic fine particles is too small, the fluidity of the developer may decrease, resulting in poor triboelectric charging properties of the toner, and an appropriate amount of positive charge is not imparted to the toner. This may result in fogging and image unevenness. Also,
When the content ratio is excessive, some of the specific inorganic fine particles may exist in a free state from the toner particles, and as a result, the free specific inorganic fine particles may adhere to and transfer to the carrier particles, or the developing device The toner adheres and accumulates on the inner wall of the toner, the developing sleeve, the regulation blade, etc., and eventually the triboelectricity of the toner becomes poor, making it difficult to apply an appropriate amount of positive charge to the toner (fogging, image).
A two-degree drop may occur.

The electrostatic image developer of the present invention may basically be a one-component developer consisting only of magnetic toner, or a two-component developer consisting of a non-magnetic toner and a magnetic carrier. Although it may be used, a two-component developer is particularly preferred.

The non-magnetic toner is a particle powder containing a colorant and other additives in a binder, and the magnetic toner is a particle powder containing a colorant, a magnetic substance, and other additives in a binder. It is a particulate powder composed of The average particle size of the toner is usually preferably about 5 to 20 nm. Other additives that can be used include, for example, a fixability improving agent, a charge control agent, a cleaning performance improving agent, and the like.

The binder for the toner is not particularly limited, and resins conventionally used for this type of use can be used. Specifically, for example, polystyrene resins, copolymers obtained from at least two or more monomers selected from styrene monomers, acrylic ester monomers, and methacrylic ester monomers, polystyrene-butadiene Resin, polyester resin, epoxy resin, polyamide resin, polyurethane resin, etc. can be used.

Among these, those that do not inhibit the positive chargeability of the toner are:
In particular, copolymers obtained from at least two or more monomers selected from polystyrene resins, styrene l-mers, acrylic ester m-M ester monomers, and methacrylic ester monomers can be preferably used.

Examples of colorants include carbon blank, phthalocyanine blue, benzidine yellow, nigrosine dye, aniline blue, calco oil blue, chrome yellow,
Dyes and pigments such as ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride, malachite green offsalate, lamp black, and rose bengal can be used. These substances may be used alone or in combination, and the content of the colorant is usually preferably 1 to 15% by weight of the toner.

Examples of fixing property improvers include polyolefins, fatty acid metal salts, fatty acid esters and fatty acid ester waxes, higher fatty acids, higher alcohols, liquid or solid paraffin waxes, amide waxes, polyhydric alcohol esters, silicone resins, and aliphatic fluorocarbons. etc. can be used.

As the charge control agent, for example, a metal complex dye or the like can be used.

As the cleaning property improver, for example, zinc stearate, calcium stearate, fatty acid metal salts such as stearic acid, polymer fine particles such as methyl methacrylate-Ha particles, styrene fine particles, etc. can be used.

When the toner is a magnetic toner, a magnetic material is contained in the binder. This magnetic material has an average particle size of 0.1~
It is preferably contained in the binder in the form of a fine powder of 1 MY and uniformly dispersed in the binder.

The content of the magnetic material is usually preferably 10 to 70 parts by weight, particularly preferably 20 to 50 parts by weight, per 100 parts by weight of the toner. Such magnetic materials include iron, ferrite, magnetite, and other ferromagnetic metals or alloys such as cobalt, nickel, etc., or compounds containing these elements, and materials that do not contain ferromagnetic elements but are subjected to appropriate heat treatment. Alloys that exhibit ferromagnetic properties, such as manganese-copper-aluminum,
A type of alloy called Heusler alloy containing manganese and copper such as manganese-copper-tin, chromium dioxide, and others can be used.

When the electrostatic image developer of the present invention is a two-component developer,
The carrier used in combination with the non-magnetic toner is not particularly limited.

Specifically, carriers made of magnetic particles, resin-coated carriers in which the surface of magnetic particles are coated with a specific resin, or magnetic fine particle dispersion in which fine magnetic particles are dispersed in resin particles. A mold carrier or the like can be used.

As the magnetic material used for the carrier, for example, ferromagnetic metals or alloys such as iron, ferrite, magnetite, cobalt, nickel, etc., or compounds containing these elements, etc. can be used. The average particle diameter of the carrier is usually preferably about 10 to 500 μm, particularly preferably 20 to 200 nm. If the average particle size of the carrier is too small, an electrostatic latent image, that is, a phenomenon in which carrier particles adhere to the image area, may occur, resulting in a defective image.If the average particle size of the carrier is too large, the toner may be rubbed The surface area for charging becomes smaller, and as a result, the amount of poorly charged toner increases and image unevenness may occur.

Next, the electrostatic image developing method of the present invention will be explained.

In the electrostatic image developing method of the present invention, a negative electrostatic t'l1jl image formed on the surface of an organic photoreceptor is processed using an electrostatic image developer (hereinafter referred to as "a specific developing agent") containing the specific inorganic fine particles. toner image is formed by developing the toner image.

The organic photoreceptor is usually constructed by laminating a photosensitive layer containing a photoconductive semiconductor made of an organic compound on a conductive support. The photosensitive layer may be composed only of a photoconductive semiconductor made of an organic compound, or may be composed of the photoconductive semiconductor dispersed in a binder made of a resin.

The photosensitive layer includes a carrier generation layer containing a carrier generation substance that absorbs visible light and generates charged carriers, and a carrier generation layer that transports one or both of the positive and negative carriers generated in this carrier generation layer. It is preferable to use a so-called functionally separated type photosensitive layer configured by combining a carrier transport layer containing a carrier transport substance. In this way, by assigning the two basic functions necessary for the photosensitive layer, namely carrier generation and carrier transport, to separate layers, the range of materials that can be used in the composition of the photosensitive layer is widened, and each It becomes possible to independently select the @IJ Prize or material system that optimally performs the function, and by doing so, it is possible to achieve the characteristics required in the image forming process, such as high surface potential when charged and charge retention. It becomes possible to construct an organic photoreceptor having excellent properties such as high performance, high photosensitivity, and high stability in repeated use.

As carrier-generating substances in the photosensitive layer, for example, andanthrone pigments, perylene derivatives, phthalocyanine pigments, azo dyes, indigoid dyes, etc. can be used. Examples of carrier transport substances include carbazole M4 derivatives, oxadiazole derivatives, triarylamino derivatives, polyarylalkane derivatives, hydrazone derivatives, pyrazoline derivatives, stilbene derivatives,
Styryl triarylamino derivatives and the like can be used. It is preferable that the carrier generation layer has a thickness of usually 0.01 to 2 nm, and the carrier transport layer has a thickness of usually 1 to 30 nm.

When forming a photosensitive layer by dispersing a photoconductive semiconductor made of a functional compound in a binder made of a resin, examples of the resin that can be used as the binder include polyethylene, polypropylene, acrylic resin, and methacrylic resin. , vinyl chloride resin, vinyl acetate resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, polycarbonate resin, silicone resin, melamine resin, addition polymerization type resin, polyaddition type resin, polycondensation type resin, and Copolymer resins containing two or more of the repeating units of these resins, such as vinyl chloride-vinyl acetate copolymer resins, vinyl chloride-vinyl acetate-maleic anhydride copolymer resins, styrene-acrylic copolymers Examples include insulating resins such as resins, and polymeric organic semiconductors such as poly-N-vinylcarbazole.

In the organic photoreceptor, a metal sheet made of, for example, aluminum, nickel, copper, zinc, palladium, silver, indium, tin, platinum, gold, stainless steel, steel, brass, etc. can be used as the conductive support.

The specific structure of the organic photoreceptor is not particularly limited, and various structures can be adopted. Further, an organic photoreceptor whose surface potential when charged is, for example, -400 to -1000 V can be particularly preferably used.

FIG. 1 is an explanatory diagram showing an example of a developing device that can be suitably used to carry out the electrostatic image developing method of the present invention.

Reference numeral 10 denotes an organic photoreceptor, which has the shape of a rotating drum that is rotated in the direction of arrow The photosensitive layer 10B containing is laminated. A charger and an exposure optical system (not shown) are arranged upstream of the development space 24, and the charger first sets the surface of the organic photoreceptor 10 to be developed at a temperature of -400 to -1, for example.
It is charged to a constant negative potential within the range of 000V,
Next, an exposure optical system (not shown) projects an optical image of the original onto the developed surface of the organic photoreceptor 10, and an electrostatic latent image corresponding to the original is formed on the developed surface, and this electrostatic latent image is moved to the developing space 24, and the electrostatic latent image is developed in the developing space 24.

11 is a developing sleeve, and this developing sleeve 11 is
The developing sleeve 11 has a rotating drum shape made of a non-magnetic material such as aluminum, and a magnet 12 is disposed inside the developing sleeve 11 . This magnet body 12 is made up of a plurality of N and S magnets arranged along the circumference of the developing sleeve 11. These developing sleeves 11 and (1 stone body 12) constitute a developing side transport carrier, and in a specific example, the developing sleeve 11 is arranged in the direction of arrow Y, that is, in the direction of movement of the organic photoreceptor 10 in the developing space 24. The magnets 12 are rotated to move in the same direction, and the magnets 12 are fixed, for example.

In the present invention, the rotation direction of the developing sleeve 11 is not particularly limited, and the magnet body 12 may be rotated in an appropriate direction.

The N, 5ift poles constituting the magnet body 12 are magnetized so that the magnetic flux strength on the surface of the developing sleeve is usually about 500 to 1500 Gauss, and the magnetic force causes 220 particles of developer to be applied to the surface of the developing sleeve 11. A developer layer (magnetic blank) 23 is formed in which the developer layer 23 stands up like a brush.

Reference numeral 13 denotes a regulating blade, which is made of a magnetic or non-magnetic material and is used to regulate the height and amount of the developer layer 23 reaching the developing space 24. Reference numeral 14 denotes a cleaning blade, and this cleaning blade 14 is used to scrape off and remove the developer remaining on the surface of the developing sleeve 11 after development. The surface of the developing sleeve 11 that has been cleaned by the cleaning blade 14 comes into contact with the developer 22 again in the developer reservoir 15, and a new magnetic brush is formed on the surface, and after this magnetic brush is regulated by the regulating blade 13, it enters the developing space. 24.

15 is a developer reservoir; 16 is a stirring screw; in the developer reservoir 15, the toner and carrier constituting the developer 22 are mixed and dispersed by the stirring screw 16;
This makes it possible to make the toner uniform once. Also,
The carrier of the developer 22 is used repeatedly, while the toner is consumed each time development is performed. Therefore, new toner in the toner hopper 17 is transferred to the developer reservoir 15 by the supply roller 18 having a recessed portion on its surface. will be replenished accordingly.

Reference numeral 19 denotes a bias power supply, and 20 denotes a protective resistor. This bias voltage rA19 applies a bias voltage necessary for development to the developing sleeve 11 via the protective resistor 20. This bias voltage is preferably a DC voltage of about 50 to 500V, for example.

In developing an electrostatic latent image, it is preferable that the tip of the magnetic brush be in contact with the surface of the organic photoreceptor 10 in order to achieve uniform development. The distance between () (cut) is
Organic photoreceptor 10 and developing sleeve 1 in developing space 24
It is preferable that the gap (D sd) is approximately 0.8 times the gap (D sd) between the
．． Preferably, the number of fins is 0. When the gap (D sd) is too small, the developability may deteriorate; on the other hand, when the gap (D sd) is too large, toner scattering tends to occur and the image may become unclear.

In the apparatus configured as described above, when the developing sleeve 11 rotates, the magnitude and direction of the magnetic field on its surface sequentially change, so that the carrier particles in the magnetic brush formed on the surface of the developing sleeve 11 rotate and vibrate. At the same time, the developing sleeve 110 is moved into the developing space 24 following the rotational movement of the developing sleeve 110, and as a result, the toner particles attached to the surface of the carrier particles by electrostatic force are conveyed to the developing space 24.

Next, the image forming method of the present invention will be explained.

In the image forming method of the present invention, a negative static T1 latent image is formed on the surface of the organic photoreceptor (VI image forming step), this electrostatic layer image is developed with the specific developer (developing step), The toner image obtained by development is electrostatically transferred to a transfer material (transfer step), and the toner image on the transfer material is heated in contact with a heat roller coated with fluororesin or silicone resin to fix it properly. A fixed visible image is formed in step), while the developer remaining on the surface of the organic photoreceptor is cleaned with a cleaning blade after the transfer step, and the surface of the organic photoreceptor is returned to its original clean state in cleaning step). to be restored.

In the latent image forming step, the surface of the organic photoreceptor is charged to a uniform negative potential (charging step), and then a light image of the document is projected onto the charged surface of the organic photoreceptor (exposure step).
As a result, an electrostatic latent image made of electrostatic charges is formed on the surface of the organic photoreceptor.

Specifically, in the charging step, the entire image forming area on the surface of the organic photoreceptor is charged to a potential of, for example, about -400 to -1000V using, for example, a corona charger, and in the exposure step, the charging An exposure optical system comprising, for example, a light source, a reflecting mirror, and a lens produces a reflected light image or a transmitted light image of the document on the surface of the organic photoreceptor whose surface is charged to a uniform negative potential during the process. The image is formed, thereby forming a negative electrostatic latent image corresponding to the original on the surface of the organic photoreceptor.

In the transfer step, an electrostatic transfer method can be preferably used. Specifically, for example, a transfer device that generates an alternating current corona discharge is placed so as to face the organic photoreceptor through the transfer material, and the alternating current corona discharge is applied to the transfer material from the back side of the organic photoreceptor. The toner carried on the surface is transferred to the surface of the transfer material.

In the cleaning step, a cleaning blade is used. This cleaning blade is preferably made of urethane rubber, for example, and in this case, cleaning performance and durability are improved. The cleaning blade is usually placed in a state in which it is lightly and elastically pressed against the surface of the photoreceptor, and cleaning is accomplished by scraping off toner remaining on the surface of the photoreceptor.

In the first stage of this cleaning process, it is preferable to add a static elimination process to eliminate static electricity from the surface of the organic photoreceptor in order to facilitate cleaning.This static elimination process can be performed, for example, using a static eliminator that generates AC corona discharge. can.

In the fixing process, fixing is performed by a contact heating method using a heat roller fixing device having a heat roller coated with a fluororesin or silicone resin. The heating roller may be configured with a backup roller placed in opposition to the heating roller, and a heat source for heating the heating roller, or may further be configured with a cleaning roller placed in opposition to the heating roller. Specifically, as a heat roller, a coating layer made of a fluorine-based resin such as Teflon (polytetrafluoroethylene manufactured by DuPont) or a silicone-based resin is applied to the surface of a core material made of metal such as iron or aluminum. It is preferable to use the one provided and configured.

Moreover, as the bank up roller, one constructed by providing a coating layer made of silicone rubber or the like on the surface of a metal core material can be preferably used.

FIG. 2 is an explanatory diagram showing an example of an image forming apparatus that can be suitably used to carry out the image forming method of the present invention.

Reference numeral 30 denotes a cabinet, and at the top of the cabinet 30 there are provided a glass document mounting table 32 for placing the document 31 and a platen cover 33 for covering the document 31. A paper feed tray 41 into which transfer paper 40 is placed is provided at one end of the cabinet 30, and a paper discharge tray 42 is provided at the other end. 43 and 44 are paper feed rollers, and 45 is a paper discharge roller.

Reference numeral 50 denotes an organic photoreceptor for forming a negative electrostatic latent image, and this organic photoreceptor 50 has a rotating drum shape. Around the organic photoreceptor 50, from the upstream side to the downstream side in the rotational direction, a corona charger 51, an exposure optical system 52, a magnetic brush developer H53, and an electrostatic transfer device 54 are arranged.
, a separator 55, and a blade type cleaning device 56 are arranged.

The exposure optical system 52 includes a first mirror unit 63 consisting of a light source 61 and a first mirror 62, and a second mirror unit 63 consisting of a pair of mirrors arranged in order along the optical path from the first mirror unit 63 to the organic photoreceptor 50. 2 mirror unit 64
, a lens 65 , a mirror 66 , and a groic mirror 67 . The first mirror unit 63 is arranged below the document mounting table 32 to display the document! ! The second mirror unit 64 is provided movably so as to be scanned with respect to the mounting table 2, and the second mirror unit 64 corresponds to the moving speed of the first mirror unit 63 so as to keep the optical path length from the document scanning point to the organic photoreceptor 50 constant. It is set up so that it can be moved. When the original 31 placed on the original placing table 32 is illuminated by the slit-shaped illumination light scanned by the exposure optical system 52, the slit-shaped reflected light images of the original 31 sequentially formed by scanning are rotated. The images are sequentially projected onto the developing surface of the organic photoreceptor 50.

Reference numeral 70 denotes a contact heating type heat roller fixing device. It is made up of.

In the above apparatus, the surface to be developed of the organic photoreceptor 50 is charged to a uniform negative potential by the corona charger 51, and then imagewise exposed by the exposure optical system 52, so that the surface of the organic photoreceptor 50 is
Negative static 1 corresponding to the original on the surface to be developed! A latent image is formed. This negative electrostatic latent image is then developed by the magnetic brush developing device 53 to form a toner image corresponding to the original. The toner image on the organic photoreceptor 50 is electrostatically transferred onto the transfer paper 40 by the electrostatic transfer device 54, and the toner image on the transfer paper 40 is heated and fixed by the heat roller fixing device 70 to form a fixed image. On the other hand, the surface of the organic photoreceptor 50 that has passed through the electrostatic transfer device 54 is rubbed by a blade-type cleaning device 56, and the toner remaining on the surface is scraped off, resulting in the original clean surface. In addition, it is subjected to the charging process by the corona charger 51 again.

[Specific examples]

Hereinafter, specific examples and comparative examples of the present invention will be described, but the present invention is not limited to these examples.

(Manufacture of inorganic fine particles) (1) Non-imitation particles A (for the present invention) 1 of cetylpyridinium chloride, which is an amino compound
A treatment liquid was prepared by dissolving 0 parts by weight of hexamethyldisilazane rsZ6079J (manufactured by D-Re Silicone Co., Ltd.), which is a silicone compound, in 80 parts by weight of hexane.

Next, 1 part of silica fine particles "Aerosil 200J (manufactured by Nippon Aerosil Co., Ltd.)" was placed in a mixer, and while rotating, 100 parts by weight of the above treatment liquid was gradually added dropwise to it. The mixture was placed in a flask and dried by heating for 1 hour while stirring, thereby obtaining inorganic fine particles whose surfaces were treated with an amino compound and a silicone compound.This inorganic fine particle A was referred to as "inorganic fine particle A." The average particle size of primary particles is 12 years old, BE
The specific surface area measured by the T method was 102 m''/g.

(2) Inorganic fine particles B (for the present invention) 5 parts by weight of methylidinetrisaniline, which is an amino compound, and 15 parts by weight of alcohol-modified silicone oil rsF8427J (manufactured by Tou Silicone Co., Ltd.), which is a silicone-based compound, A treatment liquid was prepared by dissolving it in 80 parts by weight of toluene.

Next, inorganic fine particles whose surfaces had been treated with an amino compound and a silicone compound were obtained by the same treatment as in the production of inorganic fine particles A, except that 100 parts by weight of the above treatment liquid was used. This inorganic fine particle B is referred to as "inorganic fine particle B"
The average particle diameter of the primary particles was 7 mm, and the specific surface area by BET method was 132 m''/g.

(3) A-free fine particles C (for the present invention) 10 parts by weight of triethanolamino, which is an amino compound, and silicone varnish rKR, which is a silicone compound.
-295J (manufactured by Shin-Etsu Silicone Co., Ltd.) was dissolved in 70 parts by weight of xylene to obtain a treatment solution of 1JF4.
Manufactured.

Next, 100 parts by weight of the above treatment liquid and 100 parts of silica fine particles "Aerosil 300J (manufactured by Nippon Aerosil Co., Ltd.)" were added.
Inorganic fine particles whose surfaces were treated with an amino compound and a silicone compound were obtained in the same manner as in the production of inorganic fine particles A, except that parts by weight were used. This will be referred to as "inorganic fine particles C." The inorganic fine particles C have an average primary particle diameter of 13sa and a specific surface area of 84m"7g by the BET method.
Met.

(4) Inorganic fine particles D (for comparison) Silica fine particles "Aerosil 200j (manufactured by Nippon Aerosil Co., Ltd.) were placed in a closed Henschel mixer heated to 100°C, and amino group-containing silicone oil was added to isopropyl alcohol to the silica fine particles. Dissolved solution (
The viscosity is 1200 cps, the amino equivalent is 3500), and the processing amount of the amino group-containing silicone oil is 2.0% by weight.
The particles were stirred at a high speed while being sprayed at a ratio such that the following results were obtained, and then dried at a temperature of 150° C. to obtain n-free fine particles for comparison whose surfaces were treated with an amino group-containing silicone oil. These are referred to as "inorganic fine particles D."

(5) Inorganic fine particles E (for comparison) Silica fine particles [Aerosil 200j (manufactured by Nippon Aerosil Co., Ltd.) were placed in a closed Henschel mixer heated to 70°C, and the silica fine particles were mixed with an amino group-containing silane coupling agent. Did you dissolve T-aminopropyltriethoxysilane in alcohol? 8 liquid, the processing amount of the amino group-containing silane coupling agent is 5.0% by weight.
The mixture was stirred at high speed while being sprayed at a ratio such that the following results were obtained, and then dried at a temperature of 120° C. to obtain Im-free fine particles for comparison whose surfaces had been treated with an amino group-containing silane coupling agent.

This is referred to as "Ja-free fine particles E."

<Example 1> (1) Production of toner 100 parts by weight of polystyrene-n-butyl acrylate copolymer (copolymerization weight ratio = 82:1B) and 1 part by weight of carbon black [Mogul Lj (manufactured by Capoft)]
0 parts by weight and 2 parts by weight of the metal-containing dye were mixed in a V-type blender, then melted and kneaded with two rolls, then cooled, coarsely pulverized with a hammer mill, further finely pulverized with a jet mill, and then Classified using a wind classifier, the average particle size was 11. A non-magnetic toner of ON was obtained. This is referred to as "toner 1".

(2) Manufacture of developer Add 50 parts by weight of the above-mentioned toner 1 to 0.00 parts by weight of the above-mentioned inorganic fine particles A.
By adding 5 parts by weight and mixing these with a Henschel mixer, inorganic fine particles are attached to or implanted onto the surface of the toner particles and held therein. By mixing 1 part of 95 caps of the above ingredients, an electrostatic image developer of the present invention, which is a two-component developer, was obtained. This is referred to as "developer l".

(3) Live-action test 0 Test 1 (Live-action test under room temperature environmental conditions) An organic photoreceptor for forming a negative electrostatic latent image, a contact type magnetic brush developer, and a corona transfer for generating alternating current corona discharge. A heat roller with a diameter of 30φ whose surface layer is made of Teflon (polytetrafluoroethylene manufactured by Devon Co., Ltd.) and a silicone rubber surface layer rKE-1300RTV
An electrophotographic copying device Rr U Bix 1, which is equipped with a heat roller fixing device made of a back amp roller made by J (manufactured by Shin-Etsu Chemical Co., Ltd.) and a cleaning device made of a cleaning blade made of urethane rubber.
550MRJ (manufactured by Konishi Roku Photo Industry Co., Ltd.) modified machine under room temperature environmental conditions of a temperature of 20°C and a relative humidity of 60%, using the developer 1 described above to form a copy image 30,000 times in succession. and evaluated each of the following items. The results are shown in Table 1 below.

The above-mentioned organic photoreceptor has a negative chargeable two-layer structure formed using an anthrone-based pigment as a carrier-generating substance and a carbazole derivative as a carrier-transporting substance, and a rotating drum-shaped aluminum conductive layer. It is constructed by laminating it on a support.

The surface potential (highest potential) of the organic photoreceptor when it is charged is -700V, the gap (Dsd) between the photoreceptor and the developing sleeve in the developing space is O, hm, and the distance between the tip of the regulating blade and the developing sleeve is 1 (Hcut) is 0.6
auw, The magnet body is a fixed type, the magnetic flux density on the surface of the developing sleeve is 800 Gauss, and the bias voltage applied to the developing sleeve is -100 V in DC voltage.

■Fog “Sakura Densitometer” (manufactured by Konishiroku Photo Industry Co., Ltd.)
The determination was made by measuring the relative density of a white background portion with a document density of 0.0 with respect to a copied image. Note that the white background reflection density was set to 0.0. In the evaluation, when the relative concentration is less than 0.01, it is defined as rOJ, and when it is 0.01 or more and less than 0.03, it is "rOJ".
Cases of 0.03 or more were marked as "x".

■Image density "Sakura densitometer" (manufactured by Konishiroku Photo Industry Co., Ltd.)
was used to measure the relative density of a white background portion with an original density of 0.0 with respect to a copied image.

■i! The i-quality copied image was visually judged from three points: image omission, image unevenness, and sharpness. The evaluation was ``x'' if it was poor and had a practical problem, ``△'' if it was slightly defective but at a practical level, and ``○'' if it was good.

■Toner scattering Visually observe the inside of the copying machine and the copied image. If the toner scattering is almost not observed and the image is in good condition, mark it as "○." If the toner scattering is slightly reduced but still at a practical level, mark it as "△."
”, and cases where a large amount of toner scattering was observed and there was a problem in practical use were rated “×”.

■Cleanability After repeating the formation of the image, the surface of the modified illuminant was visually observed immediately after being cleaned with the cleaning blade, and the problem was determined by the presence or absence of deposits on the surface of the mechanophosphor. . The evaluation is "○" if there is almost no deposits observed and the product is in good condition, "△" if the deposits are slightly compressed but at a practical level, and a lot of deposits are observed and there is a problem in practical use. The case was marked as “×”.

(2) Durability of the fixing device Judgment was made based on the occurrence of an off-cent phenomenon, the occurrence of jams, and the staining of the back side of the transfer paper, which are caused by dirt on the heat roller and backup roller that constitute the fixing device. Evaluation,
A case where the result is poor and has a practical problem is rated as "x", a case where it is slightly poor but at a practical level is rated as "△", and a case where it is good is rated as "○".

0 Test 2 (Live-action test under high-temperature environmental conditions)A live-action test was conducted in the same manner, except that the environmental conditions were a high-temperature environment of 30°C and 80% relative humidity, and each of the above items was evaluated.Results are shown in Table 2 below.

<Example 2> A developer was obtained in the same manner as in Example 1, except that 0.4 parts by weight of inorganic fine particles B was used instead of inorganic fine particles A.

This will be referred to as "Developer 2".

A photographic test was carried out in the same manner as in Example 1, except that this developer 2 was used, and evaluations were made in the same manner. The results will be explained in the first section below.
Shown in Table and Table 2.

<Example 3> A developer was obtained in the same manner as in Example 1, except that 0.6 parts by weight of inorganic fine particles C was used instead of R-free fine particles A. .

This will be referred to as "Developer 3".

A photographic test was carried out in the same manner as in Example 1, except that this developer 3 was used, and evaluations were made in the same manner. The results will be explained in the first section below.
Shown in Table and Table 2.

<Comparative Example 1> In producing the developer of Example 1, the developer was produced in the same manner as in Example 1, except that 0.4 parts by weight of comparative inorganic fine particles was used instead of the inorganic fine particles. Obtained. This is referred to as "comparative developer 1."

A photographic test was carried out in the same manner as in Example 1, except that this comparative developer I was used, and evaluations were made in the same manner.

The results are shown in Tables 1 and 2 below.

Comparative Example 2 A developer was produced in the same manner as in Example 1, except that 0.4 parts by weight of inorganic fine particles for comparison was used instead of W1 fine particles. I got it. this"
"Comparative developer 2".

A photographic test was carried out in the same manner as in Example 1, except that this comparative developer 2 was used, and evaluations were made in the same manner.

The results are shown in Tables 1 and 2 below.

As can be understood from the results in Tables 1 and 2,
According to the developers 1 to 3 of the present invention, the toner has good triboelectric charging properties and fluidity, and therefore, in the developing process,
A negative electrostatic latent image formed on an organic photoreceptor by magnetic brush development can be developed well without toner scattering, and in the transfer process, it can be transferred at a high transfer rate by electrostatic transfer means. In addition, in the cleaning process, a cleaning blade with a simple structure can perform good cleaning, and in the fixing process, a hot roller fixing device can perform good fixing without causing any off-setting phenomenon. As a result, it is possible to form a good image with clear image quality without fogging, image missing, or image unevenness, and with high image density.

Even when performing image forming processes many times, the heat roller and buffer roller in the heat roller fixing device do not get dirty, and the usable life of the rollers is significantly extended, and even under high temperature environmental conditions. Good images can be stably formed.

On the other hand, according to Comparative Developer 1, since the comparative inorganic fine particles whose surface was treated with amino group-containing silicone oil were used, the triboelectric charging properties of the toner were inferior.
As a result, an unclear image with a lot of fog and low image density is obtained. Furthermore, when the image forming process is performed many times, the blur of the image gradually increases, resulting in a defective image at an early stage.

In addition, according to Comparative Developer 2, since comparative inorganic fine particles E whose surfaces were treated with an amino group-containing silane coupling agent were used, the surface of the inorganic fine particles was completely treated with the amino group-containing silane coupling agent. Therefore, the negatively charged sites and hydrophilic sites of the inorganic fine particles remain, resulting in poor triboelectric charging properties of the toner, resulting in an unclear image with a lot of fog and low image density. Further, the triboelectric charging properties become unstable due to the influence of humidity, and therefore, under high temperature environmental conditions, fogging occurs significantly, image density decreases considerably, and images become significantly blurred.

Furthermore, when we conducted an actual photographing test over 50,000 consecutive Vts using the developers 1 to 3 according to the present invention and applying the developing method according to the present invention, good results similar to those shown in Tables 1 and 2 were obtained. Obtained.

In addition, when we conducted a continuous photographing test over 70,000 times using the developers 1 to 3 according to the present invention and applying the image forming method according to the present invention, the same good results as shown in Tables 1 and 2 were obtained. was gotten.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of an electrostatic image developing apparatus that can be suitably used to carry out the electrostatic image developing method of the present invention, and FIG. FIG. 2 is an explanatory diagram showing an example of an image forming apparatus that can be suitably used. 10... Organic photoreceptor 10A... Conductive support 10B... Photosensitive N11... Developing sleeve 12...
・Magnet body 13...Regulation blade 23...
・Developer layer (magnetic brush) 24...Development space 30...Cabinet 31...Document 32...Document mounting table 4
0... Transfer paper 50... Organic photoreceptor 51
...Corona charger 52...Exposure optical system 53.
...Magnetic brush developer 54...Electrostatic transfer device 56...
・Blade type cleaning device 70...Heat roller fixing device

Claims (1)

[Scope of Claims] 1) An electrostatic image developer comprising inorganic fine particles whose surfaces have been treated with an amino compound and a silicone compound. 2) The electrostatic image developer according to claim 1, wherein the inorganic fine particles are made of silica. 3) A negative electrostatic latent image formed on the surface of a photoreceptor made of an organic photoconductive semiconductor is developed using an electrostatic image developer containing inorganic fine particles whose surface has been treated with an amino compound and a silicone compound. An electrostatic image developing method characterized by developing. 4) A latent image forming step in which a negative electrostatic latent image is formed on the surface of a photoreceptor made of an organic photoconductive semiconductor, and this electrostatic latent image is transferred to inorganic fine particles whose surface has been treated with an amino compound and a silicone compound. a development step in which the toner image obtained by the development is electrostatically transferred to a transfer material, and a developer remaining on the surface of the photoreceptor after the transfer step. a cleaning step of cleaning the toner image on the transfer material with a cleaning blade; and a fixing step of heating and fixing the toner image on the transfer material using a heat roller fixing device having a heat roller coated with a fluororesin or silicone resin. An image forming method characterized by: