JP2974545B2 - Electrostatic latent image developing developer and image forming method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developer for developing an electrostatic image and an image forming method for visualizing an electrostatic image in an image forming method such as an electrophotographic method, an electrostatic recording method and an electrostatic printing method. . More specifically, the present invention relates to a developer for developing an electrostatic image, which is uniformly and strongly charged in a direct method or an indirect electrophotographic developing method and provides a high quality image with little environmental dependency, and an image forming method using the developer.

[0002]

2. Description of the Related Art Conventionally, electrophotography has been disclosed in U.S. Pat. No. 2,297,691, Japanese Patent Publication No. 42-23910.
JP-A (U.S. Pat. No. 3,666,363) and JP-B-43-24748 (U.S. Pat.
361) are known. Generally, an electrical latent image is formed on a photoreceptor by various means using a photoconductive biomaterial, and then the latent image is developed using a developing powder (hereinafter referred to as toner). After a toner image is transferred to a transfer material as described above, fixing is performed by heating, pressure, heating and pressurizing, or solvent vapor to obtain a copy.

In the case where a process for transferring a toner image is provided, a process for removing residual toner on a photoreceptor is usually provided.

[0004] A developing method for visualizing an electric latent image using a toner includes, for example, a magnetic brush method described in US Pat. No. 2,874,063 and US Pat. No. 2,61.
There is a cascade development method described in US Pat. No. 8,552, and a powder cloud method described in US Pat. No. 2,221,776. U.S. Pat. No. 3,909,258 discloses a method using a magnetic toner, a method using a conductive toner, a method using dielectric polarization of toner particles, and a method using a magnetic toner.
Japanese Patent Application Laid-Open No. 42121 and Japanese Patent Application Laid-Open No. 55-18656 discloses a method of developing a latent image by flying toner particles.

Conventionally, in an image forming apparatus including a step of electrostatically transferring a transferable toner image formed on the surface of a latent image carrier (photoreceptor) to a paper or plastic sheet transfer material, Using an image carrier that runs endless, such as a cylindrical or endless belt, a biased transfer device is pressed against it and a transfer material is passed between them to form a toner image on the latent image carrier side. (For example, an apparatus as disclosed in JP-A-59-46664) has been proposed.

In such an apparatus, the pressing force of the transfer roller against the latent image carrier is adjusted by adjusting the pressing force of the transfer roller against the latent image carrier, as compared with the transfer means utilizing corona discharge which has been widely used in the past. Since the area of adsorption to the body can be enlarged and the transfer material is positively supported at the transfer site, there is a risk of improper synchronization due to the transfer material conveying means and transfer deviation due to loops, curls, etc. existing in the transfer material. It is easy to respond to the recent demands for shortening the transfer material transport path and reducing the diameter of the latent image carrier as this type of image forming apparatus is downsized. On the other hand, in a device that performs transfer by contact, the transfer current is supplied from the contact portion,
Some pressure must be applied to the transfer device. When the contact pressure is applied, pressure is also applied to the toner image on the latent image carrier, and toner aggregation is likely to occur.

Further, when the surface of the latent image carrier is made of a resin, adhesion occurs between the toner aggregate and the latent image carrier, and transfer to the transfer material is hindered.
A phenomenon in which a portion having strong adhesion is not transferred at all and an image is lost occurs.

This phenomenon is particularly remarkable in a line portion of 0.1 to 2 mm. This is because the line portion has a large amount of toner due to an edge phenomenon, aggregation tends to occur due to pressure, and loss due to transfer tends to occur. The transferred image at this time is a copy in which the image is formed only in the outline portion,
This is called "transfer missing". FIG. 1A shows a normal image without a hollow portion, and FIG. 1B shows an image with a hollow portion.

The "missing during transfer" is particularly liable to occur in thick paper of 100 g / cm ² or more, transparency film having high smoothness, and the like. Since transfer materials such as cardboard and film are thick, it is conceivable that the effect of the transfer electric field is small, and that the pressure is increased and that the transfer material is likely to drop out.

As described above, the transfer device using the contact member has many advantages such as miniaturization and low power, but tends to narrow the conditions for the transfer material.

Heretofore, a corona discharger has been known as a charging means in an electrophotographic apparatus. However, corona dischargers have problems such as the need to apply a high voltage and the generation of a large amount of ozone.

Therefore, recently, the use of contact charging means without using a corona discharger has been studied. Specifically, a voltage is applied to a conductive roller serving as a charging member, and the roller is brought into contact with a photosensitive member serving as a member to be charged to charge a surface of the photosensitive member to a predetermined potential. If such a contact charging means is used, the voltage can be reduced as compared with the corona discharger, and the amount of generated ozone can be reduced.

For example, in Japanese Patent Publication No. 50-13661, a low voltage can be applied when charging photosensitive paper by using a roller having a core covered with a dielectric material made of nylon or polyurethane rubber.

However, when the above-mentioned contact charging means is used, if sufficient contact with the member to be charged cannot be maintained,
There is a problem that charging failure occurs. At the contact portion, if the residual developer is present on the surface of the photoconductor, the charging member is in contact with a predetermined contact pressure, so that the residual developer adheres to the surface of the charging member and the photoconductor, thereby affecting the image. There is also a problem that is.

In the contact charging device as described above, a DC voltage or a DC voltage with an AC voltage superimposed thereon is applied to the charging member. At this time, in the vicinity of the contact portion between the charging member and the photosensitive drum, abnormal charging and flying motion of the residual developer having a particularly small particle size and light weight are repeated. In the situation where the residual developer is easily attracted and embedded in the developer,
This is very different from the case where non-contact charging means using a conventional corona discharger is used.

As a toner applied to these developing methods, a fine powder in which a dye or a pigment is dispersed in a natural or synthetic resin has been used. For example, a dispersion of a colorant in a binder resin such as polystyrene is
Particles pulverized to about μm are used as toner particles. As the magnetic toner, a toner containing magnetic particles such as magnetite is used. In the case of a system using a two-component developer, the toner is usually used as a mixture with carrier particles such as glass beads, iron powder and ferrite particles.

On the other hand, in recent years, small and inexpensive personal use copying machines and laser printers have emerged. In these small machines, from the maintenance-free standpoint, a cartridge in which a photoconductor, a developing device, a cleaning device and the like are integrated. A method is used. It is advantageous to use a one-component magnetic developer because the structure of the developing device can be simplified as the developer.

In such a method using a dry developer, in order to form a visible image of good quality, it is necessary that the developer has high fluidity and uniform chargeability. . To this end, conventionally, silicic acid fine powder has been added to and mixed with toner powder. Since the silica fine powder is hydrophilic as it is, the developer to which it is added causes aggregation due to moisture in the air to decrease the fluidity, or in extreme cases, the absorption of the silica fine powder by the moisture absorption of the silica fine powder causes The charging performance is reduced. Therefore, use of a silica fine powder subjected to a hydrophobizing treatment is disclosed in JP-A-46-578.
No. 2, JP-A-48-47345, JP-A-48-47345
No. 47346. Specifically, this is a method in which a silicic acid fine powder is reacted with a silane coupling agent to hydrophobize silanol groups on the surface of the fine silicic acid powder with an organic group. As the silane coupling agent, for example, dimethyldichlorosilane, trimethylalkoxysilane and the like are used.

Further, in order to sufficiently perform the hydrophobic treatment,
After being treated with a silane coupling agent, A / 2
Japanese Patent Application Laid-Open No. 63-13936 discloses that a silica fine powder which is treated with 5 ± A / 30 parts by weight (A: specific surface area of the fine silica powder) and has a hydrophobicity of 90% or more is used.
No. 7, JP-A-63-139369, and the like.

However, in a developer in which an inorganic fine powder such as the above-mentioned silica fine powder is externally added to the toner, the developer itself has a strong polishing effect and strongly rubs the surface of the photoreceptor during image formation. Scratching or scratching the photoconductor surface,
Alternatively, there has been a problem that fusing or filming of the residual developer due to the scratches occurs. This problem is more likely to occur when a contact member such as a transfer device using the contact member or the charging member is in contact with the surface of the photoreceptor with a predetermined contact pressure.

In recent years, the size of toner particles has been reduced for the purpose of improving the image quality of a copy, and it has been more difficult to uniformly charge the toner than before. As the toner particles become smaller, the surface area of the toner per unit weight increases, and the possibility that the toner particles adhere to each other due to external pressure increases.In order to maintain higher fluidity, a larger amount of inorganic fine powder is used than before. It is necessary to add and mix the toner to the toner, and the above problem tends to be more remarkable.

In order to prevent this, like silica fine powder,
It is effective to increase the flow improver. However,
Particularly, in a machine having a high process speed, there is a limit to the increase in the amount of the photosensitive member because the surface of the photosensitive member is liable to be damaged and the fixability of the toner is deteriorated.

In recent years, the problem with waste has become apparent, and in the process of transferring a toner image, the remaining toner on the photosensitive member is removed and collected. There is an increasing need to reduce the amount of collected toner. In particular, in order to reduce the collected amount of toner having a fine particle diameter, it is required to further increase the uniform chargeability of the toner.

[0024]

SUMMARY OF THE INVENTION An object of the present invention is to provide a developer for developing an electrostatic image and an image forming method which solve the above-mentioned problems.

An object of the present invention is to provide a developer for electrostatic charge development which is stable against environmental changes such as high temperature and high humidity and low temperature and low humidity, and can always exhibit good characteristics.

Another object of the present invention is to provide an electrophotographic method including processes such as development, fixing, and cleaning, in which a stable image can be obtained even when a large number of images are formed over a long period of time. To provide an agent.

Another object of the present invention is to solve various problems associated with the conventional chargeable toner and to uniformly and strongly charge the toner.
An object of the present invention is to provide a developer that visualizes an electrostatic charge image and provides a high-quality image without fogging or toner scattering around edges.

In particular, it is an object of the present invention to provide a developer capable of uniformly and strongly charging a toner having a fine particle diameter, and having high image quality and excellent developability.

Another object of the present invention is to provide a transfer process in which a high-quality image faithful to a latent image can be obtained regardless of the conditions of a transfer material in an image forming method by pressure transfer such as a contact transfer method. An object of the present invention is to provide an image forming method having the following.

Another object of the present invention is to provide an image forming method in which the phenomenon of "missing during transfer" does not occur or the phenomenon is suppressed.

Another object of the present invention is to provide an image forming method using a toner which gives a high quality image without any omission during transfer even when a thick transfer material is used.

Another object of the present invention is to prevent the surface of the charging member and the member to be charged from being scratched or scraped by the developer, and to prevent contamination such as adhesion of the developer to the surface of the member. An object of the present invention is to provide an image forming method having a charging step capable of maintaining sufficient contact and preventing charging failure and charging unevenness.

[0033]

More specifically, the present invention relates to an electrostatic image comprising a fine powder treated with a silicone oil or silicone varnish after being treated with a toner and a silane coupling agent. In the developing developer, the fine powder treated with the silicone oil or the silicone varnish after the treatment with the silane coupling agent is a ratio of the fine powder treated with the silane coupling agent before the treatment with the silicone oil or the silicone varnish. The silane coupling agent has a BET specific surface area of 0.4 to 0.8 times the surface area, and the silane coupling agent has a general formula R _m SiY _{n wherein} R represents an alkoxy group or a chlorine atom, and m represents 1 to 3 Y represents an alkyl group, a vinyl group, a glycidyl group, a hydrocarbon containing a methacrylic group, and n represents an integer of 3 to 1]. It relates to an electrostatic image developer according to claim.

Further, according to the present invention, an electrostatic image carrier is charged, an electrostatic image is formed on the charged electrostatic image carrier, and the electrostatic image is developed with a developer to form a toner image. To
In an image forming method of transferring to a transfer material by a transfer means contacting the electrostatic image carrier with a linear pressure of 3 g / cm or more via the transfer material, the developer is treated with a toner and a silane coupling agent. And then treated with a silicone oil or silicone varnish, and then treated with a silane coupling agent and then treated with a silicone oil or silicone varnish. Having a BET specific surface area of 0.4 to 0.8 times the specific surface area of the fine powder treated with the silane coupling agent before the silane coupling agent, wherein the silane coupling agent has a general formula R _m SiY _n [wherein R Represents an alkoxy group or a chlorine atom, m represents an integer of 1 to 3, Y represents a hydrocarbon containing an alkyl group, a vinyl group, a glycid group, and a methacryl group. Shown, n is an integer of 3-1]
And an image forming method characterized by the following.

The present inventors have studied various fine powders. As a result, by using fine powders having a limited specific surface area ratio before and after treatment with silicone oil or silicone varnish, high-performance development was achieved. It has been found that an agent can be obtained.

In the present invention, by controlling the physical properties, particularly the surface properties, of the fine powder before the treatment to a state different from those conventionally known, the treatment state of the silicone oil or silicone varnish can be made more uniform. It has been found that the performance of a developer using the fine powder is further improved.

In the present invention, the linear pressure is calculated by the following equation.

(Linear pressure) [g / cm] = (total pressure applied to the transfer member) [g] ÷ (length in contact) [cm]

When the contact pressure is less than 3 g, transfer failure of the transfer member and insufficient transfer due to insufficient transfer current undesirably occur. Particularly preferably, the linear pressure is 20 g or more.

The transfer device used in the present invention includes a transfer roller as shown in FIG. 2 or a transfer belt as shown in FIG. FIG. 2 is a schematic configuration diagram of a main part of a typical image forming apparatus of this type. The illustrated apparatus includes a cylindrical electrostatic charge image carrier (which extends in a direction perpendicular to the plane of the paper and rotates in the direction of arrow A). Hereinafter, it is referred to as “photoconductor”)
1. A conductive transfer roller 2 is provided in contact with the roller.

A primary charger for uniformly charging the surface of the photoreceptor 1 and a light image such as an image-modulated laser beam and light reflected from an original are projected on the charged surface. An exposure unit that attenuates the potential of the portion to form an electrostatic latent image,
Although a developing device, a cleaner for removing residual toner remaining on the surface of the photoreceptor after transfer, and other members necessary for image formation are provided, they are omitted.

The transfer roller 2 includes a core 2 a and a conductive elastic layer 2.
b, and the conductive elastic layer 2b is made of polyurethane or EPDM (ethylene-ethylene) in which a conductive material such as carbon is dispersed.
Volume resistance about 10 ⁶ formed of propylene rubber)
It is made of an elastic material of 〜１０10 ¹⁰ Ω · cm. Core 2a
Is biased by the constant voltage power supply 3.

A bias is applied to the metal core 2a by the constant voltage power supply 8. As the bias condition, a current value of 0.
1 to 50 μA and a voltage (absolute value) of 100 to 5000 V (preferably 500 to 4000 V) are preferable.

FIG. 3 shows an application of the present invention to a transfer belt. The transfer belt 6 is supported and driven by a conductive roller 7. The transfer roller is normally pressed by pressing the end bearing of the cored bar 2a.

Next, the contact charging step applicable to the image forming method of the present invention will be specifically described.

FIG. 4 is a schematic structural view of a contact charging device showing one embodiment of the present invention. Reference numeral 1 denotes a photosensitive drum as an object to be charged, which is formed by forming an organic photoconductor (OPC) 1b as a photosensitive layer on an outer peripheral surface of a drum base 1a made of aluminum at a predetermined speed in a direction indicated by an arrow. Rotate. In this embodiment, the photosensitive drum 1 has an outer diameter of 30 mmφ.
Reference numeral 42 denotes a charging roller which is a charging member brought into contact with the photosensitive drum 1 with a predetermined pressure, and a conductive rubber layer 42b is provided on a metal core 42a, and a surface layer 42c which is a release coating on the peripheral surface thereof. Is provided. The surface layer in this embodiment is a release film, and it is preferable to provide a release film in terms of matching with the image forming method of the present invention. However,
If the resistance of the release coating is too high, the photoconductor drum 1 is not charged. If the resistance is too low, a large voltage is applied to the photoconductor drum 1, and the drum is likely to be damaged and pinholes are likely to occur. The volume resistivity of the release coating is 10 ⁹ to 10 ¹⁴
Ω · cm is good, and the thickness of the release film at this time is 3.0 μm.
m is preferable. The lower limit of the thickness of the film is good as long as there is no film peeling and no peeling. For example, the lower limit is about 5 μm.

In this embodiment, the outer diameter of the charging roller 42 is 12
The conductive rubber layer 42b was made of EPDM, and the surface layer 41c was made of 10 μm thick nylon resin. The hardness of the charging roller 41 was 54.5 ° (ASKER-C). E denotes a power supply for applying a voltage to the charging roller 41, and supplies a predetermined voltage to the metal core 42a of the charging roller 42. In FIG. 4, E denotes a DC voltage, but a voltage obtained by superimposing an AC voltage on the DC voltage is preferable.

Preferred process conditions in this case are shown below.

Contact pressure: 5 to 500 g / cm AC voltage: 0.5 to 5 V _pp AC frequency: 50 to 3000 Hz DC voltage: -200 to -900 V

FIG. 5 is a schematic structural view of a contact charging member showing another embodiment of the present invention.

The same members as those in FIG. 4 are denoted by the same reference numerals, and the description thereof will not be repeated.

The contact charging member 53 of this embodiment is in the form of a blade which is brought into contact with the photosensitive drum 1 in a forward direction with a predetermined pressure. 53b is supported, and a surface layer 5 serving as a releasable film is provided at a contact portion with the photosensitive drum 1.
3c is provided. The thickness of the surface layer 53c is 10
μm nylon was used. According to this embodiment, the same operation and effect as those of the above-described embodiment can be obtained without problems such as adhesion between the blade and the photosensitive drum.

In the above-described embodiment, a roller-shaped or blade-shaped charging member is used. However, the charging member is not limited to this, and may have another shape.

In this embodiment, the charging member is composed of a conductive rubber layer and a release coating, but a high resistance layer is provided between the conductive rubber layer and the surface of the release coating to prevent leakage to the photoreceptor. (For example, a hydrin rubber layer with small environmental fluctuation) may be provided.

As the release coating, PVDF (polyvinylidene fluoride) or PVDC (polyvinylidene chloride) may be used instead of the nylon resin. As the photoconductor, amorphous silicon, selenium, ZnO or the like can be used. In particular, when amorphous silicon is used for the photoreceptor, if the softening agent of the conductive rubber layer adheres to the photoreceptor even a little, compared with the case where other materials are used, the image flow becomes worse, so the conductive rubber layer The effect of the insulating coating on the outside is great.

The cleaning step according to the present invention will be described. In general, the photosensitive drum after the transfer of the toner image is wiped and removed by a cleaning member such as a blade or a roller to remove the remaining toner and other contaminants after the transfer, and the surface is cleaned and repeatedly used for image formation. You.

The cleaning step can be performed simultaneously in the charging step, the developing step, or the transfer step related to the electrophotographic method.

The present invention is particularly effective for an image forming apparatus in which the surface of a photoreceptor is an organic compound. This is because, when the organic compound forms the surface layer, the organic compound easily adheres to the binder resin contained in the toner, which can be satisfactorily avoided by the present invention.

As the surface material of the photoreceptor used in the present invention, silicone resin, vinylidene chloride resin, ethylene-vinyl chloride resin, styrene-methyl methacrylate resin, styrene-acrylonitrile resin, styrene resin,
Examples include polyethylene terephthalate and polycarbonate. The present invention is not limited to these, and other monomers or copolymerization or blending between the exemplified resins can be used.

The present invention is particularly effective for an image forming apparatus having a small-diameter drum whose photosensitive member has a diameter of 50 mm or less. In the case of a small-diameter photosensitive drum, since the curvature is large even at the same linear pressure, pressure concentration is likely to occur at the abutting portion, and the photosensitive drum surface is easily scratched.
It can be suppressed well.

It is considered that the same phenomenon occurs in the belt photosensitive member, and the present invention is also effective for an image forming apparatus having a radius of curvature of 25 mm or less at the transfer portion.

Next, the developer of the present invention will be described.

In the silicone oil or silicone varnish treatment according to the developer of the present invention, the surface can be completely covered by uniformly applying the silicone oil or silicone varnish to the surface of the fine powder.
Moisture resistance is dramatically improved.

Since the fine powder according to the present invention is treated with a silicone oil or silicone varnish having a strong negative charge, it is strongly negatively charged. Sex can be given. This characteristic is effective for a magnetic one-component toner in which charging becomes unstable easily. In particular, it is effective for a toner having a fine particle diameter intended for high image quality.

The material of the fine powder used in the present invention is preferably an inorganic compound. For example, fine powders of Group 3 or Group 4 metal oxides such as silicic acid, alumina, and titanium oxide are preferable. As the preferred fine powder, both a so-called dry method produced by vapor phase oxidation of a silicon halide and a so-called fumed silica and a so-called wet silica produced from water glass or the like can be used. . Dry silica having less silanol groups on the surface and in the interior of the fine silicic acid powder and having less production residues such as Na ₂ O and SO ₃ ^2- is preferred. In the case of fumed silica, for example, it is also possible to obtain a composite fine powder of silica and another metal oxide by using another metal halide such as aluminum chloride or titanium chloride together with a silicon halide in the production process. Can be used as silica. The particle size is preferably in the range of 0.001 to 2 μm as an average primary particle size, and particularly preferably fine powder such as silica fine powder in the range of 0.002 to 0.2 μm is used. .

In order to uniformly treat the silicone oil or silicone varnish in accordance with the gist of the present invention, the fine powder is adjusted to have a hydrophobicity of 70% or more, more preferably 80% or more. Is preferred.

The degree of hydrophobicity of the fine powder in the present invention is measured by the following method. 100 ml of pure water and 1 g of a sample are placed in a sealed-type container and shaken with a shaker for 10 minutes.
After shaking, the water layer was collected after the powder layer and the water tank were separated, and the transmittance was measured at a wavelength of 500 nm with reference to the pure water of the blank containing no fine powder, and the transmittance value was used as the value. The degree of hydrophobicity of the fine powder.

The solid content of the silicone oil or silicone varnish used in the present invention is generally represented by the following formula:

[0069]

[Outside 1] Wherein R represents a C ₁ -C ₃ alkyl group, and R ′ is
It indicates a period of silicone oil modification such as alkyl, halogen-modified alkyl, unsubstituted phenyl and substituted phenyl, and R ″ represents a C ₁ -C ₃ alkyl group or an alkoxyl group.]

Examples include dimethyl silicone oil, alkyl-modified silicone oil, a-methylstyrene-modified silicone oil, chlorophenyl silicone oil, and fluorine-modified silicone oil.

The above silicone oil is preferably at 25 ° C.
Having a viscosity of 50 to 1000 centistokes is used. If the viscosity is too low and the molecular weight is too low, volatile components may be generated in the silicone oil due to heat treatment or the like. If the viscosity is too high and the molecular weight is too high, the processing operation becomes difficult.

As the method of treating the silicone oil or silicone varnish, a known technique is used.

For example, the fine powder and the silicone oil may be directly mixed using a mixer such as a Henschel mixer, or a method in which the silicone oil is sprayed on the base fine powder. More preferably, a method of dissolving or dispersing silicone oil in an appropriate solvent, mixing with a base fine powder, and removing the solvent is preferable.

The treatment of the silicone oil or silicone varnish in the present invention is preferably performed so that the specific surface area after the treatment becomes 0.4 to 0.8 times the specific surface area before the treatment. It is more preferable that the amount of carbon attached is 3 to 8% by weight of the fine powder. here,
The attached amount of carbon is a value obtained by an elemental analyzer (CHN meter), and the specific surface area of the fine powder is N in the BET method.
₂ Value obtained from adsorption. 80% hydrophobicity of fine powder by silicone oil or silicone varnish treatment
More preferably, it is 90% or more.

In consideration of the transferability, which is the greatest object of the present invention, the releasability of the toner particles developed on the surface of the photoreceptor from the surface of the latent image carrier is improved, and the adhesion between the toner particles by external pressure is further improved. In order to prevent this, a fine powder uniformly treated with silicone oil or silicone varnish having a small surface energy is very effective.

The reasons for limiting the above processing conditions are that the reduction of the specific surface area of the fine powder by the silicone oil or silicone varnish treatment is small, that the treatment with the silicone oil or silicone varnish is small, or that the treatment is uneven. . In such a case, the releasing effect between the toner particles and the surface of the photoreceptor and between the toner particles decreases, and accordingly, the transferability also decreases. In addition, the moisture resistance is insufficient, and under high humidity, the fine silica powder absorbs moisture, so that a high-quality image cannot be obtained, or the charging becomes nonuniform, so that it is difficult to obtain good results. In particular, when applied to a developer having a toner having a fine particle diameter, in the step of transferring a toner image, there arises a problem that the amount of the residual toner on the photosensitive member cannot be reduced. On the other hand, if the specific surface area of the fine powder is excessively reduced by the silicone oil or silicone varnish treatment, agglomeration and coalescence of the fine silica powder occur, and when applied to a developer, the fluidity is not sufficiently improved. , Developability, transferability, durability, etc.
Satisfactory results are unlikely to be obtained.

When the developer of the present invention is used, transferability is extremely excellent, and in particular, it is possible to almost eliminate omission during transfer of a transparency film which has been difficult to overcome conventionally. Furthermore, even when a toner having a small particle size that is disadvantageous to transfer is used, a sufficient effect can be obtained even if the amount of the fine powder is not so much increased, and even if excessively added, the surface of the fine powder is almost completely treated. And has very excellent lubricity, so that scratches on the surface of the photosensitive drum are reduced.

It is excellent in developability, durability, environmental stability, etc., and can provide very good images stably.

In the image forming method having the contact charging step of the present invention, the effect of preventing the toner from being fused to the surface of the photoreceptor is considered as follows.

The reason why the toner is fused to the surface of the photoconductor is that the surface of the photoconductor is rubbed by the contact charging member to which the developer slipped from the cleaning blade adheres in the image forming apparatus having the contact charging device. The light-weight developer with a small particle diameter remaining on the surface of the photoreceptor is pressed against the surface of the photoreceptor by the contact charging member,
This is because sticking and embedding occur.

The developer of the present invention has a fine powder uniformly and sufficiently treated with a lubricating silicone oil or silicone varnish under specific conditions, and the fine powder present on the surface of the magnetic developer. Since the lubricating property works, it works as a lubricant between the contact charging member and the photoconductor, so that the surface of the photoconductor is not damaged and fusion is prevented.

Since the developer is strongly and uniformly charged, it causes the above-mentioned fusion. The developer remaining on the photoreceptor surface is reduced.

In general, in treating silicone oil or silicone varnish, the amount of the solid content of the silicone oil or silicone varnish to be charged is preferably 3 to 50 parts by weight, more preferably 5 to 30 parts by weight, per 100 parts by weight of the fine powder. Department is good.

The fine powder used in the present invention is first treated with a silane coupling agent to increase its hydrophobicity, and then treated with silicone oil or silicone varnish.

In general, when only the silicone oil or silicone varnish treatment is performed, if the amount of the silicone oil for covering the surface of the fine powder is large, aggregates of the fine powder are liable to be formed during the processing. Therefore, it is necessary to pay close attention to the processing steps of the silicone oil or the silicone varnish since problems such as deterioration of the properties are caused. Therefore, it is better to treat the fine powder with a silane coupling agent and then treat it with silicone oil or silicone varnish to remove the aggregation of the fine powder while maintaining good moisture resistance. We can show enough.

The silane coupling agent used in the present invention has the general formula R _m SiY _n [wherein R represents an alkoxy group or a chlorine atom,
Represents an integer of 1 to 3, Y represents a hydrocarbon containing an alkyl group, a vinyl group, a glycid group, and a methacryl group, and n represents 3
Represents an integer of ~ 1]. For example, typically, dimethyldichlorosilane, trimethylchlorosilane, allyldimethylchlorosilane, hexamethyldisilazane, allylphenyldichlorosilane, benzyldimethylchlorosilane, vinyltriethoxysilane, γ-methacryloxypropyltriethoxysilane, vinyl Triacetoxysilane, divinylchlorosilane, dimenylvinylchlorosilane and the like can be mentioned.

More preferably, after pre-treatment with a coupling agent having a mono- or dimethyl group such as dimethyldichlorosilane, dimethyldimethoxysilane, monomethyltrichlorosilane, monomethyltrimethoxysilane, etc., R-Si-Y ₃ or R ₂ -Si-Y _{2 When} treated with a coupling agent having a trimethyl group such as hexamethyldisilazane, trimethylchlorosilane, trimethylmethoxysilane, etc., the hydrophobicity of the fine powder itself before silicone oil or silicone varnish treatment is kept high. In addition, since the affinity of the fine powder surface with silicone oil or silicone varnish is improved, more uniform treatment can be performed.

When a silane coupling agent is used, it is generally preferable to charge 2 to 30 parts by weight, more preferably 5 to 25 parts by weight, per 100 parts by weight of the fine powder.

The silane coupling agent treatment of the fine powder may be performed by a dry process in which a vaporized silane coupling agent is reacted with a cloud of the fine powder by stirring or the like, or a silane coupling method in which the fine powder is dispersed in a solvent. The treatment can be performed by a generally known method such as a wet method in which an agent is dropped.

The amount of the processed fine powder applied to the developer is preferably 0.01 to 20 parts by weight, more preferably 0.1 to 3 parts by weight, based on 100 parts by weight of the magnetic toner.

Examples of the binder resin used in the toner of the present invention include homopolymers of styrene such as polystyrene and polyvinyltoluene and substituted products thereof; styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, and styrene-acryl. Methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl acrylate copolymer, styrene-methyl methacrylate Copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether Copolymer, styrene-vinyl methyl Styrene-based copolymers such as ketone copolymers, styrene-butadiene copolymers, styrene-isobrene copolymers, styrene-maleic acid copolymers, styrene-maleic acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate , Polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, tempen resin, phenolic resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, paraffin wax, carnauba wax, etc. Is mentioned. These can be used alone or in combination.

As a coloring material which can be added to the toner of the present invention, conventionally known pigments or dyes such as carbon black and copper phthalocyanine can be used.

In the case of a magnetic toner, a powder of a ferromagnetic metal such as iron, cobalt, or nickel, or an alloy or compound such as magnetite, γ-Fe ₂ O ₃ , or ferrite;
A magnetic powder of a magnetic material such as another ferromagnetic alloy is used together with the binder resin.

Additives may be added to the toner as needed. Examples of such additives include lubricants such as Teflon powder and zinc stearate powder, fixing aids (eg, low molecular weight polyethylene), and metal oxide powders such as tin oxide powder as a conductivity-imparting agent.

The toner generally has a weight average particle size of 3 to 15 μm.
m is used.

The image forming method of the present invention will be described with reference to FIG.

The surface of the photoreceptor is negatively charged by a primary charger 702, and a digital latent image is formed by image scanning by exposure 705 with a laser beam.
Sleeve 70 containing magnet 11 and magnet 714
One-component magnetic developer 710 of the developing device 709 provided with
The reversal development of the latent image is carried out. Photosensitive drum 1 in developing section
The conductive substrate is grounded, and an alternating bias, a pulse bias, and / or a DC bias are applied to the developing sleeve 704 by a bias applying unit 712. Transfer paper P
Is conveyed to the transfer section, the roller transfer means 2 charges the transfer paper P from the rear surface (the surface opposite to the photosensitive drum side) with the voltage application means 8 to thereby develop the developed image (toner image) on the photosensitive drum surface. ) Is the transfer paper P by the contact transfer means 2.
Transcribed up. The transfer paper P separated from the photosensitive drum 701 is subjected to a fixing process by a heating and pressing roller fixing device 707 to fix a toner image on the transfer paper P.

The one-component developer remaining on the photosensitive drum after the transfer step is removed by a cleaning device 708 having a cleaning blade. After the cleaning, the photosensitive drum 701 is gradually charged by the erase exposure 706, and again,
The process starting from the charging process by the primary charger 702 is repeated.

The electrostatic image carrier (photosensitive drum) has a photosensitive layer and a conductive substrate, and moves in the direction of the arrow. A non-magnetic cylindrical developing sleeve 704 serving as a toner carrier rotates in the developing section so as to advance in the same direction as the surface of the electrostatic image holding member. Inside the non-magnetic cylindrical sleeve 704, a multi-pole permanent magnet (magnet roll) as a magnetic field generating means is arranged so as not to rotate. The one-component insulative magnetic developer 710 in the developing device 709 is applied on a non-magnetic cylindrical surface, and the friction between the surface of the developing sleeve 704 and the magnetic toner particles causes the magnetic toner particles to have a negative triboelectric charge, for example. Given. Further, a magnetic doctor blade 711 made of iron
Close to the cylindrical surface (interval 50 μm to 500 μm)
By arranging the multi-pole permanent magnet so as to face one magnetic pole position, the thickness of the developer layer can be reduced (from 30 μm to 300 μm).
m) A uniform developer layer is formed so as to be in non-contact with a developer layer thinner than the gap between the electrostatic image holder 1 and the toner carrier 704 in the developing section. This toner carrier 704
Is adjusted so that the sleeve surface speed is substantially equal to or close to the speed of the electrostatic image holding surface. Magnetic doctor blade 711
Alternatively, the opposed magnetic poles may be formed using permanent magnets instead of iron. In the developing section, an AC bias or a pulse bias may be applied to the toner carrier 704 by the bias unit 712. This AC bias is f 200 ~
It is sufficient that 4,000 Hz and Vpp are 500 to 3,000 V.

When the magnetic toner particles are transferred in the developing portion, the toner particles are transferred to the electrostatic image side by an electrostatic force on the electrostatic image holding surface and the action of an AC bias or a pulse bias.

Instead of the magnetic doctor blade 711,
The thickness of the developer layer may be regulated by pressing using an elastic blade made of an elastic material such as silicone rubber, and the developer may be applied on the developer carrier.

FIG. 8 shows an image forming apparatus having a contact charging means 742 to which a voltage is applied from a bias applying means 743 and a corona transfer means 703.

FIG. 9 shows an image forming apparatus having the contact charging means 742 and the contact transfer means 2.

[0104]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on embodiments. However, this does not limit the embodiment of the present invention at all.

The number of parts described in Examples and Comparative Examples indicates parts by weight.

Example 1 100 parts of styrene-butyl acrylate-divinylbenzene copolymer (copolymerization ratio: 80 / 19.5 / 0.5, weight average molecular weight: 3)
20,000) 100 parts of magnetic material (average particle size of about 0.2 μm) 3 parts of low molecular weight polypropylene 4 parts of chromium complex of monoazo dye

The above mixture was melt-kneaded in a twin-screw kneading extruder heated to 140 ° C., the cooled kneaded material was coarsely pulverized by a hammer mill, and the coarsely pulverized material was finely pulverized by a jet mill. The material was classified and removed with a multi-segmentation classifier to obtain a magnetic toner having a weight average particle size of 6.3 μm.

Next, fine silica powder (Aerosil # 300,
After treating 100 parts of Nippon Aerosil Co., Ltd .; hydrophilic silica) with 20 parts of dimethyldichlorosilane, the mixture is further treated with 10 parts of hexamethyldisilazane to obtain a hydrophobicity of 96.
1%, carbon deposition amount 2.5wt%, BET specific surface area 172
A fine powder of m ² / g was obtained. While stirring this fine powder, 15 parts of dimethyl silicone oil (KF-96, 100CS, manufactured by Shin-Etsu Chemical Co., Ltd.) was applied by spraying.
Heat treatment at 190 ° C. for 5 hours, hydrophobicity 98.2%, carbon adhesion 8.4 wt%, BET specific surface area 115 m ² / g
To obtain fine silica powder. The change in the specific surface area due to the silicone oil treatment was 0.67 times, and the carbon adhesion amount was 5.9 wt%.

100 parts of the magnetic toner described above and 1 part of the treated fine silica powder were mixed with a Henschel mixer to obtain a one-component magnetic developer.

The one-component magnetic developer was modified from a laser beam printer LBP-811 made by Canon (using an OPC photosensitive drum) from 8 sheets / min to 16 sheets / min, and a transfer device shown in FIG. 2 was further incorporated. Image evaluation was performed using a modified machine.

The conditions of the transfer roller were as follows: the surface rubber hardness of the transfer roller was 27 °, the transfer current was 1 μA, the transfer voltage was +
2000 V and a contact pressure of 50 [g / cm]. The conductive elastic layer of the transfer roller is made of EPD in which conductive carbon is dispersed.
M and had a volume resistance of 10 ⁸ Ω · cm.

The primary charging is -700 V, a gap is set in a non-contact manner between the photosensitive drum and the developer layer on the developing drum (including magnets), and an AC bias (f = 1,800 Hz, Vpp
= 1,600 V) and DC bias (V _DC = −500)
V) was applied to the developing drum, and 8,000 images were imaged. When the toner-fixed image formed and fixed by the heating and pressurizing roller was evaluated, the image density was 1.4 or more, and there was no omission during transfer with 120 g / m ² thick paper or about 110 μm thick transparency film. The scratches on the surface of the OPC photosensitive drum were extremely small.

Plain paper for ordinary copying machines (75 g / m ² )
Evaluation was made as follows according to the state of maintaining the image density when 4,000 sheets were passed. Table 1 shows the results.

○ (good): 1.35 or more Δ (acceptable): 1.0 to 1.34 × (impossible): 1.0 or less

Example 2 100 parts of fine silica powder (Aerosil # 300 manufactured by Nippon Aerosil Co., Ltd.) were treated with 30 parts of dimethyldichlorosilane (hydrophobicity: 82.3%, specific surface area: 230 m ² /
g, carbon content: 2.2 wt%), dimethyl silicone oil (KF-96100cs, manufactured by Shin-Etsu Chemical Co., Ltd.) 15
Part was mixed with a solution diluted with a solvent, and then the solvent was evaporated under reduced pressure.
1.4%, specific surface area 120 m ² / g, carbon content 6.5
A treated silicic acid fine powder of wt% (that is, the amount of carbon deposited by silicone oil treatment: 4.3 wt%) was obtained.

Magnetic toner 10 produced in the same manner as in Example 1.
0 parts and treated silica fine powder were mixed to prepare three types of one-component magnetic developers.

[0117] In the same manner as in Example 1, 4000 images were imaged. The toner-fixed image formed and fixed by the heating and pressing roller was evaluated. Table 1 shows the results.

Example 3 Silica fine powder (Aerosil #
200) 100 parts were treated with 25 parts of dimethyldichlorosilane (hydrophobicity: 83.6%, specific surface area: 172 m)
² / g, carbon content: 1.5 wt%) and 5 parts of dimethyl silicone oil (KF-96 100cs, Shin-Etsu Chemical Co., Ltd.) diluted with a solvent were mixed, and the solvent was evaporated under reduced pressure. Thereafter, a heat treatment was performed at 180 ° C. to obtain a hydrophobicity of 84.8%, a specific surface area of 129 m ² / g, and a carbon content of 4.6 wt% (carbon adhesion amount by silicone oil treatment: 3.1 wt%). An image output test was performed in the same manner as in Example 1 except that a developer using 1.2 parts of the treated silicic acid fine powder was used. As shown in Table 1, good results were obtained except that the surface of the OPC drum after the durability was slightly more damaged.

Comparative Example A As the treated silicic acid fine powder, silicic acid fine powder (Aerosil #
200, hydrophilicity, specific surface area 200 m ² / g), 30 parts of dimethyl silicone oil (KF-96 100 cs, manufactured by Shin-Etsu Chemical Co., Ltd.) diluted with a solvent were mixed, and the solvent was evaporated under reduced pressure. Thereafter, a heat treatment was performed at 200 ° C. to obtain a hydrophobicity of 87.2% and a specific surface area of 86 m ^2.
/ G, a developer containing 0.8 parts of treated silicic acid fine powder having a carbon content of 7.9 wt% (carbon adhesion amount by silicone oil treatment: 7.9 wt%) was used in the same manner as in Example 1. An image test was performed. Table 1 shows the results.

Example 4 The same test as in Example 1 was carried out except that the developer of Example 2 was used and the contact pressure of the transfer roller with the latent image carrier was 5 g / cm. Table 1 shows the results.

Comparative Example 1 Silica fine powder (Aerosil # 3)
00) 100 parts of hydrophobic silica treated with 30 parts of dimethyldichlorosilane (the amount of carbon attached by silicone oil treatment: 0 wt%) was used, and the contact pressure of the transfer roller with the latent image carrier was 2 g / linear pressure. cm, but the durability of the image density was poor.
Only an image with noticeable voids in the character image could be obtained. In addition to the hollow area, there is a portion where the transfer blur occurs, which is caused by insufficient transfer pressure. In addition, countless fine scratches were formed on the drum surface after the durability test, and this was caused by the difference in lubricity of the silica-treated surface.

[0122]

[Table 1]

Example 5 Silica fine powder (Aerosil #
200) After treating 100 parts with 20 parts of dimethyldichlorosilane (hydrophobicity: 82.6%, specific surface area: 180 m)
² / g, carbon content: 1.1 wt%) and 15 parts of dimethyl silicone oil (KF-96 100cs, Shin-Etsu Chemical Co., Ltd.) diluted with a solvent were mixed, and the solvent was evaporated under reduced pressure. Thereafter, a heat treatment was performed at 180 ° C. to obtain a hydrophobicity of 90.8%, a specific surface area of 100 m ² / g, and a carbon content of 5.2 wt% (carbon adhesion by silicone oil treatment: 4.1 wt%). The same test as in Example 1 was conducted except that a developer using the treated silicic acid fine powder was used. Table 2 shows the results.

Example 6 Silica fine powder (Aerosil #
300) 100 parts were treated with 30 parts of dimethyldichlorosilane (hydrophobicity: 82.3%, specific surface area: 230 m)
² / g, a carbon content of 2.2 wt%) and 20 parts of dimethyl silicone oil (KF-96 100 cs, manufactured by Shin-Etsu Chemical Co., Ltd.) diluted with a solvent, and then the solvent was evaporated under reduced pressure. Heat treatment at 150 ° C., treatment with a hydrophobicity of 95.4%, a specific surface area of 120 m ² / g (0.52 times the specific surface area before the silicone oil treatment) and a carbon content of 8.5 wt% The same test as in Example 1 was performed except that a developer using fine silica powder was used. Table 2 shows the results.

Example 7 As the treated silicic acid fine powder, silicic acid fine powder (Aerosil #
300) After treating 100 parts with 35 parts of dimethyldichlorosilane (hydrophobicity: 85.8%, specific surface area: 210)
m ² / g, a carbon content of 2.6 wt%) and 5 parts of dimethyl silicone oil (KF-96 100 cs, Shin-Etsu Chemical Co., Ltd.) diluted with a solvent were mixed, and the solvent was evaporated under reduced pressure. Thereafter, a heat treatment was performed at 150 ° C. to obtain a hydrophobicity of 83.6%, a specific surface area of 125 m ² / g (0.59 times the specific surface area before the silicone oil treatment), and a carbon content of 7.1 wt%. The same test as in Example 1 was conducted except that a developer using 1.2 parts of the treated silicic acid fine powder was used.

The results were good as shown in Table 2, except that the surface of the OPC drum after the endurance was slightly damaged.

Comparative Example B As the treated silica fine powder, silica fine powder (Aerosil #
After mixing 35 parts of dimethyl silicone oil (KF-96 100cs, manufactured by Shin-Etsu Chemical Co., Ltd.) with a solvent diluted with 200, hydrophilicity, specific surface area: 200 m ² / g, the solvent was evaporated under reduced pressure. After that, a heat treatment was performed at 150 ° C. to obtain a hydrophobicity of 89.2% and a specific surface area of 80 m ^2.
/ G (0.40 of specific surface area before silicone oil treatment)
The same test as in Example 1 was carried out except that a developer using a treated silica fine powder having a carbon content of 8.0 wt% was used. Table 2 shows the results.

Example 8 The same test as in Example 5 was performed except that the contact pressure of the transfer roller with the latent image carrier was 5 g / cm.

Comparative Example 2 As treated silica fine powder, (Aerosil # 200) 10
A test was conducted in the same manner as in Example 5 except that a roller treated with 20 parts of dimethyldichlorosilane in 0 part was used, and the contact pressure of the transfer roller with the latent image carrier was changed to a linear pressure of 2 g / cm. In addition, the durability of the image density was poor, and only an image in which a character image had a noticeable void was obtained.

[0130] In addition to the hollow area, there is a portion where transfer blur occurs, which is caused by a low transfer pressure. In addition, countless fine scratches are formed on the surface of the OPC drum after the endurance, which is caused by the difference in lubricity of the silica-treated surface.

[0131]

[Table 2]

Example 9 The developer of Example 1 was loaded into an LBP printer modified from a laser beam printer LBP-8II manufactured by Canon Inc. from 8 sheets / minute to 16 sheets / minute to perform an image output test. The image density was stable at 1.4 to 1.5, the image quality was good, and the image quality was good, and the toner collected by cleaning at 15,000 images printed under normal temperature and normal humidity (23 ° C., 60% RH). Was also small.

After leaving the device under the conditions of high temperature and high humidity (32.5 ° C., 90% RH) and similarly performing an image output test on 10,000 sheets, the image density was 1.4 or more. Printing was good without any omission during transfer.

Example 10 100 parts of fine silicic acid powder (Aerosil # 200, manufactured by Nippon Aerosil Co., Ltd .; hydrophilic silica) were treated with 10 parts of dimethyldichlorosilane, and further treated with 15 parts of hexamethyldisilazane to obtain a hydrophobic substance. 98.2% conversion, 2.1 carbon deposition
A fine powder having a BET specific surface area of 155 m ² / g in wt% was obtained. While stirring the fine powder, 12 parts of dimethyl silicone oil (KF-96 100 cs) was applied by spraying and then heat-treated at 180 ° C. for 7 hours to give a hydrophobicity of 9
6.7%, carbon deposition 8.4 wt%, BET specific surface area 1
13 m ² / g of treated silica fine powder was obtained. The change in the specific surface area due to the silicone oil treatment was 0.73 times, and the carbon adhesion amount was 6.3 wt%.

Next, 100 parts of the magnetic toner of Example 1 and 1.2 parts of the treated silicic acid fine powder were mixed with a Henschel mixer to form a magnetic one-component developer. An evaluation was performed. The same good results as in Example 1 were obtained.

Example 11 100 parts of fine silica powder (Aerosil # 300) were treated with 20 parts of methyltrichlorosilane, and further treated with 5 parts of hexamethyldisilazane to obtain a hydrophobicity of 88.6% and a carbon adhesion amount. 1.8 wt%, BET specific surface area: 226 m ² / g
Was obtained. Furthermore, dimethyl silicone oil KF
After mixing the above-mentioned fine powder with 18 parts of -96 100cs diluted with a solvent, the solvent was evaporated under reduced pressure,
Heat treatment at 190 ° C. for 10 hours to give a hydrophobicity of 93.4%,
8.9 wt% of carbon deposition amount, BET specific surface area 127 m ² /
g of the treated silica fine powder was obtained. The change in the specific surface area due to the silicone oil treatment was 0.56 times, and the carbon adhesion amount was 7.1% by weight.

Next, a magnetic one-component developer was obtained in the same manner as in Example 1 except that the above-mentioned treated silicic acid fine powder was used, and the image formation was evaluated in the same manner as in Example 9. Results were obtained.

Example 12 100 parts of fine silica powder (Aerosil # 300 manufactured by Nippon Aerosil Co., Ltd.) were treated with 30 parts of dimethyldichlorosilane (hydrophobicity: 82.3%, specific surface area: 230 m ² /
g, carbon content: 2.2 wt%), dimethyl silicone oil (KF-96 100cs, manufactured by Shin-Etsu Chemical Co., Ltd.)
After 15 parts were mixed with a solution diluted with a solvent, the solvent was evaporated under reduced pressure, and a heat treatment was performed at 180 ° C. to obtain a hydrophobicity of 91.4%, a specific surface area of 120 m ² / g, and a carbon content of 6 A treated silicic acid fine powder having a concentration of 0.5 wt% (that is, an attached amount of carbon by the silicone oil treatment: 4.3 wt%) was obtained.

100 parts of the magnetic toner of Example 1 and 0.8 parts of silicic acid fine powder treated with dimethylsilicone oil after dimethyldichlorosilane treatment were mixed with a Henschel mixer to obtain a magnetic one-component developer.

Using the developer, an image was formed on 8,000 sheets at normal temperature and normal humidity and at high temperature and high humidity in the same manner as in Example 9. The same good results as in Example 9 were obtained.

Comparative Example 3 As the treated silicic acid fine powder, silicic acid fine powder (Aerosil #
300) The same test as in Example 12 was carried out except that 100 parts of dimethyldichlorosilane was treated with 30 parts.

At room temperature and normal humidity, a good image having an image density of 1.3 was obtained, but the image density decreased to 1.0 in one day at high temperature and high humidity.

Example 13 As the treated silicic acid fine powder, silicic acid fine powder (Aerosil #
200) 100 parts were treated with 20 parts of dimethyldichlorosilane (hydrophobicity: 82.6%, specific surface area: 180 m)
² / g, carbon content: 1.1 wt%) and 15 parts of dimethyl silicone oil (KF-96 100cs, Shin-Etsu Chemical Co., Ltd.) diluted with a solvent were mixed, and the solvent was evaporated under reduced pressure. Thereafter, a heat treatment was performed at 180 ° C. to obtain a hydrophobicity of 90.8%, a specific surface area of 100 m ² / g, and a carbon content of 5.2 wt% (carbon adhesion by silicone oil treatment: 4.1 wt%). The same test as in Example 12 was performed except that the treated silicic acid fine powder was used.

Even when left under high temperature and high humidity, a good image having an image density of 1.4 or more was obtained, and the printing on the transparency film was also good. A good image was obtained in an image test under each environment, and a small amount of the residual toner was collected on the photoreceptor.

Example 14 The hydrophobization degree obtained in the same manner as in Example 4 except that the treated amount of dimethyl silicone oil (KF-96 100cs, manufactured by Shin-Etsu Chemical Co., Ltd.) was changed to 20 parts as the treated silicic acid fine powder. The same test as in Example 12 was performed using a treated silicic acid fine powder having 95.1%, a specific surface area of 91 m ² / g, and a carbon content of 7.3 wt% (carbon adhesion amount by silicone oil treatment: 6.2 wt%). went.

As in Example 13, good images were obtained under each environment.

Example 15 Silica fine powder (Aerosil #
200) 100 parts were treated with 25 parts of dimethyldichlorosilane (hydrophobicity: 83.6%, specific surface area: 172 m)
² / g, carbon content: 1.5 wt%) and 5 parts of dimethyl silicone oil (KF-96 100cs, Shin-Etsu Chemical Co., Ltd.) diluted with a solvent were mixed, and the solvent was evaporated under reduced pressure. Thereafter, a heat treatment was performed at 180 ° C. to obtain a hydrophobicity of 84.8%, a specific surface area of 129 m ² / g, and a carbon content of 4.6 wt% (carbon adhesion by silicone oil treatment: 3.1 wt%). The same test as in Example 12 was performed except that the treated silicic acid fine powder was used.

When the device was left under high temperature and high humidity, a good image having an image density of 1.3 or more was obtained, and the printing on the transparency film was also good. In addition, good images were obtained in the image formation test under each environment, and the amount of the residual toner collected on the photoreceptor was small.

Example 16 As a treated silicic acid fine powder, a silicic acid fine powder (Aerosil #
300) 100 parts were treated with 30 parts of trimethylchlorosilane (hydrophobicity 92.2%, specific surface area 213 m)
² / g, carbon content: 3.5 wt%) and 10 parts of dimethyl silicone oil (KF-96 100cs, Shin-Etsu Chemical Co., Ltd.) diluted with a solvent were mixed, and the solvent was evaporated under reduced pressure. Thereafter, a heat treatment was performed at 150 ° C. to obtain a hydrophobicity of 96.3%, a specific surface area of 147 m ² / g, and a carbon content of 7.1 wt% (carbon adhesion amount by silicone oil treatment: 3.6 wt%). The same test as in Example 12 was performed except that the treated silicic acid fine powder was used.

Even when the apparatus was left under high temperature and high humidity, a good image having an image density of 1.4 or more was obtained, and printing on the transparency film was also good. A good image was obtained in an image test under each environment, and a small amount of the residual toner was collected on the photoreceptor.

Comparative Example C As the treated silicic acid fine powder, silicic acid fine powder (Aerosil #
200, hydrophilicity, specific surface area 200 m ² / g), 30 parts of dimethyl silicone oil (KF-96 100 cs, manufactured by Shin-Etsu Chemical Co., Ltd.) diluted with a solvent were mixed, and the solvent was evaporated under reduced pressure. Thereafter, a heat treatment was performed at 200 ° C. to obtain a hydrophobicity of 87.2% and a specific surface area of 86 m ^2.
/ G, a test similar to that of Example 12 was performed except that a treated silicic acid fine powder having a carbon content of 7.9 wt% (carbon adhesion amount by silicone oil treatment: 7.9 wt%) was used.

Although the image density was slightly low at 1.2 under low temperature and low humidity, a good image having an image density of 1.3 or more was obtained even when left under high temperature and high humidity, and printing on a transparency film was also possible. It was good.

Example 17 Silica fine powder (Aerosil #
300) 100 parts were treated with 30 parts of dimethylchlorosilane (prepared to have a hydrophobicity of 77.3%, specific surface area 230 m ² / g, carbon content: 2.2 wt.
%), Α-methylstyrene-modified silicone oil (KF
-410, manufactured by Shin-Etsu Chemical Co., Ltd.) was mixed with 15 parts diluted with a solvent, and the solvent was evaporated under reduced pressure.
A treated silica having a degree of hydrophobicity of 86.8%, a specific surface area of 143 m ² / g, and a carbon content of 6.1 wt% (carbon adhesion amount by silicone oil treatment: 3.9 wt%) obtained by performing a heat treatment at 0 ° C. The same test as in Example 12 was performed except that the acid fine powder was used. A good image having an image density of 1.3 or more was obtained even when left under high temperature and high humidity, and printing on the transparency film was also good. A good image was obtained in an image test under each environment, and a small amount of the residual toner was collected on the photoreceptor.

Example 18 Silica fine powder (Aerosil #
200) After treating 100 parts with 20 parts of trimethylchlorosilane (hydrophobicity: 84.1%, specific surface area: 160 m)
² / g, carbon content: 2.5 wt%), 15 parts of dimethyl silicone oil (KF-96 100 cs, manufactured by Shin-Etsu Chemical Co., Ltd.) were diluted with a solvent, sprayed, dried, and then heated at 150 ° C. And a degree of hydrophobicity of 9
2.6%, specific surface area 95m ² / g, carbon content 7.5w
t% (carbon adhesion amount by silicone oil treatment: 5.0
wt%), except that the treated silicic acid fine powder was used. A good image having an image density of 1.3 or more was obtained even when left under high temperature and high humidity, and printing on the transparency film was also good. A good image was obtained in an image test under each environment, and a small amount of the residual toner was collected on the photoreceptor.

Comparative Example 4 As the treated silicic acid fine powder, silicic acid fine powder (Aerosil #
200) The same test as in Comparative Example C was performed except that 100 parts of the resin was treated with 20 parts of dimethyldichlorosilane.

At room temperature and normal humidity, a good image having an image density of 1.3 was obtained, but the image density decreased to 1.0 in one day at high temperature and high humidity.

Example 19 As the treated silicic acid fine powder, silicic acid fine powder (Aerosil #
300) After treating 100 parts with 30 parts of dimethyldichlorosilane (hydrophobicity: 82.3%, specific surface area: 230)
m ² / g, carbon content: 2.2 wt%) and 20 parts of dimethyl silicone oil (KF-96 100 cs, Shin-Etsu Chemical Co., Ltd.) diluted with a solvent were mixed, and the solvent was evaporated under reduced pressure. After that, a heat treatment was performed at 150 ° C. to obtain a hydrophobicity of 95.4% and a specific surface area of 120 m ² / g
(0.52 times the specific surface area before silicone oil treatment),
The same test as in Example 12 was performed except that the treated silica fine powder having a carbon content of 8.5 wt% was used.

When left under high temperature and high humidity, a good image having an image density of 1.4 or more was obtained, and printing on a transparency film was also good. A good image was obtained in an image test under each environment, and a small amount of the residual toner was collected on the photoreceptor.

Example 20 Silica fine powder (Aerosil #
300) After treating 100 parts with 35 parts of dimethyldichlorosilane (hydrophobicity: 85.8%, specific surface area: 210)
m ² / g, carbon content: 2.6 wt%) and 5 parts of dimethyl silicone oil (KF-96 100cs, manufactured by Shin-Etsu Chemical Co., Ltd.) diluted with a solvent were mixed, and the solvent was evaporated under reduced pressure. After that, a heat treatment was performed at 150 ° C. to obtain a degree of hydrophobicity of 83.6%, a specific surface area of 125 m ² / g (0.59 times the specific surface area before the silicone oil treatment), and a carbon content of 7.1 wt%. The same test as in Example 12 was performed except that the treated silicic acid fine powder was used.

Even when left under high temperature and high humidity, a good image having an image density of 1.3 or more was obtained, and printing on a transparency film was also good. In addition, good images were obtained in the image formation test under each environment, and the amount of the residual toner collected on the photoreceptor was small.

Example 21 As the treated silicic acid fine powder, silicic acid fine powder (Aerosil #
200) 100 parts were treated with 20 parts of trimethylchlorosilane (hydrophobicity: 84.1%, specific surface area: 160)
m ² / g, carbon content: 2.5 wt%) and 10 parts of dimethyl silicone oil (KF-96 100 cs, Shin-Etsu Chemical Co., Ltd.) diluted with a solvent, and then the solvent was evaporated under reduced pressure. After that, a heat treatment was performed at 180 ° C. to obtain a hydrophobicity of 88.6%, a specific surface area of 90 m ² / g (0.56 times the specific surface area before the silicone oil treatment), and a carbon content of 7.0 wt%. The same test as in Example 12 was performed except that the treated silicic acid fine powder was used.

A good image having an image density of 1.4 or more was obtained even when left under high temperature and high humidity, and printing on the transparency film was also good. A good image was obtained in an image test under each environment, and a small amount of the residual toner was collected on the photoreceptor.

Comparative Example D As the treated silicic acid fine powder, silicic acid fine powder (Aerosil #
After mixing 35 parts of dimethyl silicone oil (KF-96 100cs, manufactured by Shin-Etsu Chemical Co., Ltd.) with a solvent diluted with 200, hydrophilicity, specific surface area: 200 m ² / g, the solvent was evaporated under reduced pressure. After that, a heat treatment was performed at 150 ° C. to obtain a hydrophobicity of 89.2% and a specific surface area of 80 m ^2.
/ G (0.40 of specific surface area before silicone oil treatment)
The same test as in Example 12 was performed except that the treated silica fine powder having a carbon content of 8.0 wt% was used.

Although the image density was slightly low at 1.2 under low temperature and low humidity, a good image with an image density of 1.3 or more was obtained even when left under high temperature and high humidity, and printing on a transparency film was also possible. It was good.

Example 22 Silica fine powder (Aerosil #
200) 100 parts were treated with 20 parts of trimethylchlorosilane (hydrophobicity: 84.1%, specific surface area: 160)
m ² / g, carbon content: 7.4 wt%), and 15 parts of α-methylstyrene-modified silicone oil (KF-410, manufactured by Shin-Etsu Chemical Co., Ltd.) mixed with 15 parts diluted with a solvent.
After the solvent was volatilized under reduced pressure, heat treatment was performed at 150 ° C., and treated silica fine powder having a specific surface area of 80 m ² / g (0.50 times the specific surface area before the silicone oil treatment) was used. Except for the above, the same test as in Example 12 was performed.

Even when left under high temperature and high humidity, a good image having an image density of 1.4 or more was obtained, and printing on the transparency film was also good. A good image was obtained in an image test under each environment, and a small amount of the residual toner was collected on the photoreceptor.

Example 23 The magnetic developer of Example 10 was applied to a DC voltage and an AC voltage (500 Hz, 2000 V) using an image forming apparatus (a modified laser beam printer LBP-8II manufactured by Canon) having a contact charging device shown in FIG. _PP ) and apply 16 sheets (A4)
Per minute at a normal temperature and normal humidity (25 ° C., 60% R)
H), high temperature and high humidity (32.5 ° C., 85% RH) and low temperature and low humidity (15 ° C., 10% RH) were performed on 8000 sheets, respectively, and printout images were evaluated. At the same time, the state of the charging member (roller type) and the surface of the photosensitive drum were observed.

The charging roller 2 has a diameter of 12 mm, the core has a diameter of 5 mm, and the conductive rubber layer 2b has a diameter of about 3.5 m.
m, a release coating formed of methoxymethylated nylon having a thickness of 20 μm and a total pressure of 1.2 kg.
(Linear pressure: 55 g / cm).

As a result, the image density was as good as 1.35 or more in any environment, and the toner was not fused to the photosensitive member or the charging member even after 12,000 sheets of continuous image formation. I didn't see it at all.

Example 24 To 100 parts of the magnetic toner of Example 1, 1.0 part of the dimethyldichlorosilane used in Example 12 and then treated with dimethylsilicone oil and then treated with dimethylsilicone oil were externally added using a Henschel mixer. A magnetic developer was obtained.

This magnetic developer was charged into the image forming apparatus of Example 23, and 6000 sheets were printed out in each environment in the same manner as in Example 23, and the image was evaluated. Then 10
Images were formed on up to 000 sheets, and the state of the charging member and the surface of the photosensitive drum were observed.

Table 3 shows the results.

The evaluation criteria are shown below.

Fusion level to photosensitive drum and charging member: ○ : No fusion at all △: Fusion of 1 to 3 points in A4 solid black △: Fusion of 4 to 10 points in A4 solid black … 11 points or more fused in A4 solid black

Example 25 As the treated silicic acid fine powder, 100 parts of the silicic acid fine powder (Aerosil # 200) used in Example 13 was treated with 20 parts of dimethyldichlorosilane (carbon content: 1.0%). 1
wt%), dimethyl silicone oil (KF-96.1)
After mixing 15 parts with a solvent diluted with a solvent, the solvent was evaporated under reduced pressure, and then 18 parts.
5.2 wt% of carbon content obtained by performing heat treatment at 0 ° C
(Carbon adhesion amount by silicone oil treatment: 4.1 wt
%), Except that the treated silica fine powder was used in the same manner as in Example 24 to obtain a magnetic developer.

This was evaluated in the same manner as in Example 24. Table 3
Shows the evaluation results.

Example 26 A magnetic developer was obtained in the same manner as in Example 24, except that the treated silicic acid fine powder used in Example 14 was used as the treated silicic acid fine powder.

This was evaluated in the same manner as in Example 24. Table 3
Shows the evaluation results.

Example 27 As a treated silicic acid fine powder, 100 parts of the silicic acid fine powder (Aerosil # 200) used in Example 15 was treated with 25 parts of dimethyldichlorosilane (carbon content: 1.0%). 5
wt%), dimethyl silicone oil (KF-96.1)
After mixing 5 parts with a solvent diluted with a solvent, the solvent was volatilized under reduced pressure.
4.6 wt% of carbon content obtained by performing heat treatment at ℃
(Carbon adhesion amount by silicone oil treatment: 3.1 wt%
%), Except that the treated silica fine powder was used in the same manner as in Example 24 to obtain a magnetic developer.

This was evaluated in the same manner as in Example 24. Table 3
Shows the evaluation results.

Example 28 As a treated silicic acid fine powder, 100 parts of the silicic acid fine powder (Aerosil # 300) used in Example 16 was treated with 30 parts of trimethylchlorosilane (carbon content: 3.5).
wt%), dimethyl silicone oil (KF-96.1)
After mixing 10 parts with a solvent diluted with a solvent, the solvent was evaporated under reduced pressure, and then 15 parts.
7.1 wt% of carbon content obtained by performing heat treatment at 0 ° C
(Carbon adhesion amount by silicone oil treatment: 3.6 wt.
%), Except that the treated silica fine powder was used to obtain a magnetic developer.

This was evaluated in the same manner as in Example 24. Table 3
Shows the evaluation results.

Comparative Example E As the treated silicic acid fine powder, 30 parts of dimethylsilicone oil (KF-96, 100 cs, manufactured by Shin-Etsu Chemical Co., Ltd.) was diluted with a solvent in the silicic acid fine powder Aerosil # 200 used in Comparative Example C. After the mixture was mixed with the mixture, the solvent was evaporated under reduced pressure, and then heat treatment was performed at 200 ° C. to obtain a carbon content of 7.9 wt% (carbon adhesion by silicone oil treatment: 7.9 wt%). A magnetic developer was obtained in the same manner as in Example 24 except that the treated silicic acid fine powder was used.

This was evaluated in the same manner as in Example 24. Table 3
Shows the evaluation results.

Example 29 As treated silicic acid fine powder, 100 parts of the silicic acid fine powder (Aerosil # 300) used in Example 17 was treated with 30 parts of dimethyldichlorosilane (carbon content: 2.20 parts). 2
wt.) and 15 parts of α-methylstyrene-modified silicone oil (KF-410, manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed with a solution diluted with a solvent, the solvent was evaporated under reduced pressure, and then heat-treated at 150 ° C. 5. The carbon content obtained by performing
1 wt% (carbon adhesion amount by silicone oil treatment:
(3.9 wt%) A magnetic developer was obtained in the same manner as in Example 24 except that the treated silicic acid fine powder was used.

An image forming apparatus having a contact charging device (a laser beam printer LB manufactured by Canon Inc.) shown in FIG.
(P-8II modified machine) and evaluated in the same manner as in Example 24. Table 3 shows the evaluation results.

Example 30 As treated silica fine powder, 100 parts of the silica fine powder (Aerosil # 200) used in Example 18 was treated with 20 parts of trimethylchlorosilane (carbon content: 2.5%).
wt%), dimethyl silicone oil (KF-96.1)
(00cs, Shin-Etsu Chemical Co., Ltd.) 15 parts were diluted with a solvent, sprayed, dried, and then heated at 150 ° C. to obtain a carbon content of 7.5 wt% (carbon adhesion by silicone oil treatment). : 5.0 wt%) The same test as in Example 24 was performed except that the treated silicic acid fine powder was used.

This was evaluated in the same manner as in Example 24. Table 3
Shows the evaluation results.

Comparative Example 5 Untreated silica fine powder (Aerosil # 3) was used as the fine powder.
A magnetic developer was obtained in the same manner as in Example 24 except that (00) was used.

This was evaluated in the same manner as in Example 24. Table 3
Shows the evaluation results.

Comparative Example 6 The treated silica fine powder was prepared in the same manner as in Example 1 except that 100 parts of the silica fine powder (Aerosil # 300) used in Comparative Example 1 was treated with 30 parts of dimethyldichlorosilane. In the same manner as in No. 24, a magnetic developer was obtained.

This was evaluated in the same manner as in Example 24. Table 3
Shows the evaluation results.

[0193]

[Table 3]

Example 31 Example 2 was repeated using the treated silicic acid fine powder used in Example 19.
In the same manner as in Example 4, a magnetic developer was obtained.

This was evaluated in the same manner as in Example 24. Table 4
Shows the evaluation results.

Example 32 As treated silica fine powder, 100 parts of the silica fine powder (Aerosil # 300) used in Example 20 was treated with 35 parts of dimethyldichlorosilane (specific surface area: 210 m).
² / g), dimethyl silicone oil (KF-96,1)
After mixing 5 parts with a solvent diluted with a solvent, the solvent was volatilized under reduced pressure.
Specific surface area 125 m ² / g obtained by performing heat treatment at ° C.
A magnetic developer was obtained in the same manner as in Example 24 except that the treated silicic acid fine powder (0.59 times the specific surface area before the silicone oil treatment) was used.

This was evaluated in the same manner as in Example 24. Table 4
Shows the evaluation results.

Example 33 As a treated silicic acid fine powder, 100 parts of the silicic acid fine powder (Aerosil # 200) used in Example 12 was treated with 20 parts of trimethylchlorosilane (specific surface area: 160 m 2).
² / g), dimethyl silicone oil (KF-96,1)
(00cs, Shin-Etsu Chemical Co., Ltd.) was mixed with 10 parts diluted with a solvent, and the solvent was evaporated under reduced pressure.
Specific surface area 90 m ² / g obtained by performing heat treatment at 0 ° C.
A magnetic developer was obtained in the same manner as in Example 24 except that the treated silicic acid fine powder (0.56 times the specific surface area before the silicone oil treatment) was used.

This was evaluated in the same manner as in Example 24. Table 4
Shows the evaluation results.

Comparative Example F As the treated silica fine powder, the silica fine powder used in Example 13 (Aerosil # 200, specific surface area: 200 m ² /
g) in dimethyl silicone oil (KF-96,10
0cs, manufactured by Shin-Etsu Chemical Co., Ltd.) was mixed with 35 parts diluted with a solvent, and the solvent was evaporated under reduced pressure.
Magnetic developer in the same manner as in Example 24, except that the treated silica fine powder having a specific surface area of 80 m ² / g (0.40 times the specific surface area before the silicone oil treatment) obtained by performing the heat treatment at 0 ° C. was used. I got

This was evaluated in the same manner as in Example 24. Table 4
Shows the evaluation results.

Example 34 As treated silica fine powder, 100 parts of the silica fine powder (Aerosil # 200) used in Example 22 was treated with 20 parts of trimethylchlorosilane (specific surface area: 160 m 2).
² / g), 15 parts of α-methylstyrene-modified silicone oil (KF-410, manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed with the diluted solvent, the solvent was evaporated under reduced pressure, and then heated at 150 ° C. Specific surface area 80m obtained by performing treatment
² / g (0.50 of specific surface area before silicone oil treatment)
A magnetic developer was obtained in the same manner as in Example 24 except that the treated silica fine powder was used.

An image forming apparatus having a contact charging device shown in FIG. 5 (a laser beam printer LB manufactured by Canon Inc.)
(P-8II modified machine) and evaluated in the same manner as in Example 24. Table 4 shows the evaluation results.

Comparative Example 7 Untreated silica fine powder (Aerosil # 2) was used as the fine powder.
A magnetic developer was obtained in the same manner as in Example 24 except that (00) was used.

This was evaluated in the same manner as in Example 24. Table 4
Shows the evaluation results.

Comparative Example 8 The same procedure as in Example 2 was conducted except that 100 parts of the fine silica powder (Aerosil # 200) used in Comparative Example 2 was treated with 20 parts of dimethyldichlorosilane. In the same manner as in No. 24, a magnetic developer was obtained.

This was evaluated in the same manner as in Example 24. Table 4
Shows the evaluation results.

[0208]

[Table 4]

Example 35 Using the developer of Example 1 and applying it to the image forming apparatus shown in FIG. 9 to produce an image, good results were obtained.

[0210]

According to the present invention, it is possible to provide a developer for developing an electrostatic charge image which has a high density even under an environment such as high temperature and high humidity and low temperature and low humidity and gives a high quality image.

In particular, it is possible to provide a developer having high image quality and excellent developability by uniformly and strongly charging a toner having a fine particle diameter.

According to the present invention, a high-density, high-durability stability image can be stably obtained even when a transparency film is used without causing any omission during transfer. Also,
The surface of the photoconductor drum is not easily damaged, and the durability of the photoconductor drum is improved.

Further, according to the present invention, by using a magnetic developer containing a specific fine powder as a developer,
In the image forming method, the developer has lubricating property, and a charging step in which a charging member is brought into contact with a member to be charged and a voltage is applied from the outside to perform charging, and a cleaning step of removing the developer from the member to be charged, It is possible to prevent fusion of the toner to the surface of the photoreceptor and obtain a high-quality image free from toner contamination.

[Brief description of the drawings]

FIG. 1 is a diagram schematically illustrating a toner image for explaining a state during transfer.

FIG. 2 is a schematic configuration diagram illustrating an example of a transfer device used in the image forming method of the present invention.

FIG. 3 is a schematic configuration diagram illustrating another example of a transfer device used in the image forming method of the present invention.

FIG. 4 is a schematic configuration diagram illustrating an example of a contact charging device used in the image forming method of the present invention.

FIG. 5 is a schematic configuration diagram showing another example of the contact charging device used in the image forming method of the present invention.

FIG. 6 is a schematic configuration diagram showing another example of another contact charging device used in the image forming method of the present invention.

FIG. 7 is a schematic view of an image forming apparatus for performing the image forming method of the present invention.

FIG. 8 is a schematic view of another image forming apparatus for performing the image forming method of the present invention.

FIG. 9 is a schematic view of another image forming apparatus for performing the image forming method of the present invention.

[Explanation of symbols]

 Reference Signs List 1 latent image carrier (photoconductor) 1a photoconductor drum base 1b organic photoconductor (OPC) 2 transfer roller 2a cored bar 2b conductive elastic layer 3 constant voltage power supply 4, 5 transfer material transport guide 6 transfer belt 7 conductivity Rollers 42, 53 Charging members 42a, 53a Metal cores (metal supporting members) 42b, 53b Conductive rubber layers 42c, 53c Surface layer E Power supply

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G03G 9/08

Claims (8)

(57) [Claims] 1. Treatment with toner and silane coupling agent
In a developer for developing an electrostatic image containing treated fine powder treated with a silicone oil or a silicone varnish, treated with a silane coupling agent and then treated with a silicone oil or a silicone varnish The treated fine powder has a BET specific surface area of 0.4 to 0.8 times the specific surface area of the fine powder treated with the silane coupling agent before being treated with silicone oil or silicone varnish.
And the silane coupling agent has the general formula R _m SiY _n [formula
In the formula, R represents an alkoxy group or a chlorine atom, and m represents 1
And Y represents an alkyl group, a vinyl group,
And a hydrocarbon containing a methacryl group.
Electrostatic image developer according to claim Rukoto represented by the an integer]. 2. The developer for developing an electrostatic charge image according to claim 1, wherein the treated fine powder has an attached amount of silicone oil or silicone varnish of 3 to 8% by weight in terms of an attached amount of carbon. 3. The developer for developing an electrostatic image according to claim 1, wherein the treated fine powder is a fine silica powder treated with silicone oil. 4. The treated fine powder is a hydrophobic silicic acid fine powder prepared by treating a silicic acid fine powder with dimethyldichlorosilane, then treating with hexamethyldisilazane, and then treating with dimethylsilicone oil. The developer for developing an electrostatic image according to claim 3. 5. An electrostatic image carrier is charged, an electrostatic image is formed on the charged electrostatic image carrier, and the electrostatic image is developed with a developer to form a toner image. Wherein the developer is treated with a toner and a silane coupling agent by using a transfer unit that is in contact with the electrostatic image carrier at a linear pressure of 3 g / cm or more through a transfer member.
And it contains a processing fine powder treated with silicone oil or silicone varnish after, silane coupling
The treated fine powder treated with silicone oil or silicone varnish after treatment with the agent is treated with silane coupling before treatment with silicone oil or silicone varnish.
Have a 0.4 to 0.8 times the BET specific surface area of the specific surface area of fine powder treated with bridging agent, the silane coupling agent is one
General formula R _m SiY _n [In the formula, R Arukookishi group or chlorine
Represents an atom, m represents an integer of 1 to 3, and Y represents alkyl
Containing vinyl, vinyl, glycid, and methacrylic groups
It indicates iodine, n represents an image forming method, comprising Rukoto represented by an integer of 3-1]. 6. The image forming method according to claim 5, wherein the treated fine powder has an attached amount of silicone oil or silicone varnish of 3 to 8% by weight as an attached amount of carbon. 7. The image forming method according to claim 5, wherein the treated fine powder is a silicic acid fine powder treated with silicone oil. 8. The treated fine powder is a hydrophobic silicic acid fine powder prepared by treating silicic acid fine powder with dimethyldichlorosilane, then treating with hexamethyldisilazane, and then treating with dimethylsilicone oil. The image forming method according to claim 7.