JP2002014487A - Toner and electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner having an improved dispersibility of the internal additive of the coloring agent in the binder resin and having uniform electrification distribution and to provide an electrophotographic device. SOLUTION: The toner is prepared by adding positive chargeable hydrophobic silica, low resistance metal oxide fine particles and metal acid salt-based fine particles to the toner base body containing a fluorine-based polymer having specified specific gravity and particle size.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copying machine, a laser printer, a plain paper FAX, a color PPC, a toner used in a color laser printer and a color FAX, and an electrophotographic apparatus.

[0002]

2. Description of the Related Art In recent years, electrophotographic apparatuses have been shifting from office use to personal use, and techniques for realizing miniaturization, maintenance-free operation, and the like are required. Therefore, conditions such as good maintenance properties such as recycling of waste toner and low ozone exhaust are required.

A printing process of an electrophotographic copying machine and a printer will be described. First, an image carrier (hereinafter, referred to as a photoconductor) is charged for image formation. As the charging method,
One that uses a corona charger conventionally used,
In recent years, there is a method of uniformly charging the surface of the photoconductor by a contact type charging method in which a conductive roller is directly pressed against the photoconductor in order to reduce the amount of generated ozone. After charging the photoreceptor, in the case of a copying machine, light is radiated to a copy original and reflected light is radiated to the photoreceptor through a lens system. Alternatively, in the case of a printer, an image signal is sent to a light emitting diode or a laser diode as an exposure light source, and a latent image is formed on a photoconductor by turning on and off light. When a latent image (high or low surface potential) is formed on the photoreceptor, the photoreceptor is visualized by toner (having a diameter of about 3 μm to 12 μm) which is a pre-charged colored powder. The toner adheres to the surface of the photoconductor in accordance with the level of the surface potential of the photoconductor, and is electrically transferred to copy paper. That is, the toner is positively or negatively charged in advance, and is electrically attracted from the back surface of the copy sheet by applying a charge having a polarity opposite to the polarity of the toner. As a transfer method, a method using a conventionally used corona discharger, and a transfer method in which a conductive roller is directly pressed against a photosensitive member with the aim of reducing the amount of ozone generated have been put into practical use in recent years. At the time of transfer, not all of the toner on the photoreceptor is transferred to the copy sheet, but part of the toner remains on the photoreceptor. This residual toner is scraped off by a cleaning blade or the like in the cleaning unit and becomes waste toner. Then, the toner transferred to the copy paper is fixed to the paper by heat and pressure in a fixing process.

[0004] As a fixing method, there are a pressure fixing method of passing between two or more metal rolls, an oven fixing method of passing through a heating atmosphere by an electric heater, and a hot roll fixing method of passing between heating rollers. In the thermal roll fixing method, since the surface of the heating roller and the toner surface on the copy paper come into pressure contact with each other, the thermal efficiency at the time of fusing the toner image to the copy paper is good, and the fixing can be performed quickly. However, in the hot roll fixing method, there is a disadvantage that since the toner comes into pressure contact with the surface of the heating roller in a heated and melted state, a part of the toner adheres to the roller surface and again adheres to the copy paper to cause an offset phenomenon that stains the image. As a method of preventing the offset, the surface of the heating roller is formed of a fluororesin or silicone rubber which is heat-resistant and has a good releasability from the toner, and an anti-offset liquid such as silicone oil is supplied to the surface to form a liquid thin film. A method of coating the roller surface has been adopted. In this method, odor is generated by heating liquid such as silicone oil,
In addition, extra equipment for supplying liquid is required,
The mechanism of the copying apparatus becomes complicated. In addition, in order to prevent offset with good stability, it is necessary to control the supply of liquid with high accuracy, and the copying apparatus must be expensive. Therefore, there is a demand for a toner that does not cause an offset without supplying such a liquid and that can obtain a good fixed image.

As is well known, toner for electrostatic charge development used in an electrophotographic method generally comprises a resin component, a coloring component comprising a pigment or a dye, a plasticizer, a charge controlling agent, and, if necessary, a mold release. It is composed of an additive component such as an agent. As the resin component, a natural or synthetic resin is used alone or in a suitable mixture.

The above additives are preliminarily mixed at an appropriate ratio, heated and kneaded by hot melting, pulverized by an air-flow type impact plate method, and classified into fine powder to complete a toner matrix.
Thereafter, an external additive is externally added to the toner matrix to complete the toner.

In the one-component development, the toner is composed of only a toner. However, a two-component developer can be obtained by mixing the toner and a carrier composed of magnetic particles.

In a color copying machine, a photoreceptor is charged by corona discharge using a charging charger, and thereafter, a latent image of each color is irradiated as a light signal on the photoreceptor to form an electrostatic latent image, and a first color, for example, The latent image is developed by developing with a yellow toner. Thereafter, a transfer material charged to a polarity opposite to that of the yellow toner is brought into contact with the photoconductor, and the yellow toner image formed on the photoconductor is transferred. The photoreceptor is cleaned after removing the toner remaining at the time of transfer, and is then discharged, thereby completing the development and transfer of the first color toner.

Thereafter, the same operation as that for the yellow toner is repeated for toners such as magenta and cyan, and a color image is formed by superimposing toner images of each color on a transfer material. Then, these superimposed toner images are transferred to a transfer paper charged to a polarity opposite to that of the toner, and then fixed to complete the copying.

In this color image forming method, a toner image of each color is sequentially formed on a single photoreceptor, and a transfer material wound around a transfer drum is rotated to repeatedly face the photoreceptor. A transfer drum system in which toner images of each color are transferred in a superimposed manner, and a plurality of image forming units are arranged side by side, and each toner image of each color is sequentially passed through a transfer material conveyed by a belt through each image forming unit. A continuous superimposition method in which a color image is transferred and superimposed is generally used.

On the other hand, as an example of a color image forming apparatus using the continuous transfer system, there is Japanese Patent Application Laid-Open No. 1-250970. In this conventional example, four image forming stations each including a photoreceptor, an optical scanning means, etc. are arranged for forming images of four colors, and the paper conveyed to the belt passes under the respective photoreceptors and the color is transferred. The toner images are superimposed.

Further, as another method of forming a color image by superposing toner images of different colors on a transfer material, each color toner image sequentially formed on a photoreceptor is temporarily superimposed on an intermediate transfer material, Japanese Patent Application Laid-Open No. H2-212867 discloses a method for collectively transferring the toner images on the intermediate transfer material to transfer paper.

[0013]

SUMMARY OF THE INVENTION Recently, from the viewpoint of global environmental protection, the waste toner which has been discarded without being reused in order to reduce the amount of generated ozone and regulate unlimited disposal of industrial waste is reused. There is a need for a low-temperature fixing method that reduces power consumption for fixing. Improvements have been made to toner materials in order to cope with roller transfer methods that generate less ozone, to cope with waste toner recycling, and to cope with low-temperature fixing. Furthermore, high performance toners that can be satisfied simultaneously, not alone, are important issues from the viewpoint of environmental protection.

In a copying machine, a printer, and a facsimile, different types of toners are used for different models having different process speeds. For example, in a low-speed machine, a binder resin material having high viscoelasticity and a high softening point is used in order to improve the offset resistance. Since it is difficult to obtain the heat required for fixing with a high-speed machine,
In order to enhance the fixing property, another binder resin having a different softening point and different characteristics is used. The process speed is related to the copying capacity per hour of the machine, and indicates the peripheral speed of the photoconductor. The conveying speed of the copy sheet is determined by the peripheral speed of the photoconductor. If these different toners can be shared, production efficiency can be increased and toner cost can be significantly reduced.

In the fixing step, the fixing strength, which is the adhesive force of the toner to the paper, and the offset resistance for preventing the toner from adhering to the heat roller are the controlling factors.

The toner melts and penetrates into the paper fibers by heat or pressure from the fixing roller to obtain fixing strength.
Conventionally, in order to improve the fixing characteristics, the binder resin has been improved or a release agent has been added to increase the fixing strength of fixing to paper and prevent the offset phenomenon that toner adheres to the fixing roller. are doing.

In JP-A-59-148067, an unsaturated ethylene polymer having a low molecular weight and a high molecular weight portion in a resin, a low molecular weight peak value and Mw / Mn is used, and a softening point is determined. A toner containing the specified polyolefin is disclosed. It is stated that the fixing property and the anti-offset property are ensured by this. Japanese Patent Application Laid-Open No. 56-1
Japanese Patent No. 58340 discloses a toner mainly composed of a resin composed of a specific low molecular weight polymer component and a high molecular weight polymer component. The purpose is to ensure the fixing property by the low molecular weight component and the offset resistance by the high molecular weight component. In Japanese Patent Application Laid-Open No. 58-223155, 1000
Disclosed is a toner containing a resin comprising an unsaturated ethylenic polymer having a maximum value in a molecular weight region of from 10,000 to 200,000 to 1,000,000 and having a Mw / Mn of from 10 to 40 and a polyolefin having a specific softening point. ing. It is used for the purpose of securing the fixing property by the low molecular weight component and the offset resistance by the high molecular weight component and the polyolefin.

However, when a resin having a low melt viscosity or a low molecular weight resin is used to increase the fixing strength in a high-speed machine, the toner adheres to the carrier during long-term use in the case of two-component development. So-called spent tends to occur. In the case of one-component development, the toner easily adheres to the doctor blade or the developing sleeve, and the stress resistance of the toner decreases. Further, when used in a low-speed machine, an offset in which toner adheres to the heat roller at the time of fixing tends to occur. In addition, blocking occurs in which the toners fuse together during long-term storage.

Depending on the configuration in which the high molecular weight component and the low molecular weight component are blended, it is possible to achieve both the fixing strength and the offset resistance for a narrow range of process speeds, but it is compatible with a wide range of process speeds. It is difficult. To cope with a wide range of process speeds, a certain effect can be exerted by configuring a higher molecular weight component and a lower low molecular weight component. However, in a high-speed machine, the fixing strength can be increased by increasing the low molecular weight component, but the offset resistance deteriorates, and in a low-speed machine, the effect of increasing the offset resistance can be obtained by increasing the high molecular weight component. On the other hand, when the amount of the high molecular weight component is increased, adverse effects such as a decrease in the pulverizability of the toner and a decrease in the productivity are caused.

Therefore, in contrast to a configuration in which a high molecular weight component and a low molecular weight component are blended or copolymerized, a releasing agent having a low melting point, such as polyethylene or polypropylene wax, has a releasability from a heat roller at the time of fixing. It is added for the purpose of improving the offset resistance.

However, it is difficult to improve the dispersibility of these release agents in the binder resin, the reverse polarity toner is easily generated due to poor dispersion, and fogging to the non-image area occurs. Further, an image chipping such as a brush scrape occurs at the rear end portion of the solid black image portion, thereby deteriorating the image quality. There is also a problem of filming contamination of the carrier, the photoconductor, and the developing sleeve.

In a contact type one-component developing system, an elastic blade for regulating a toner layer is used for a developing roller made of silicon resin or the like, and a supply roller made of urethane resin for supplying toner to the developing roller is used. Fusing and agglomeration due to friction between the supply roller and the developing roller occur frequently, causing image defects. Therefore, when a resin having a high molecular weight is used, an excessive load is applied, and the machine itself is greatly damaged, and productivity is reduced.

As described above, from the viewpoint of protecting the global environment in recent years, it is preferable that the waste toner remaining on the photoreceptor after transfer and recovered by the cleaning means be recycled in the developing step again. However, when the waste toner is recycled, the toner appears to be damaged due to stress applied to the waste toner in the cleaner section, the developing section, and the transport pipe when returning the waste toner to the developing section.

When the waste toner scraped off from the photoreceptor in the cleaning step is recycled by development again, if the internal additive or the colorant is poorly dispersed, the particles with reduced dispersion tend to become waste toner. Strongly, when it is mixed with new toner in the developing device, the charge amount distribution becomes non-uniform, the reverse polarity toner increases, and the quality of the copied image deteriorates.

Further, in a toner to which a low melting point component such as wax is added, filming of the wax on the photoreceptor is promoted, which causes a reduction in life. Also, short-length paper such as a postcard is conveyed by the frictional force with the photoconductor drum. However, for a photoconductor in which filming has occurred, the conveyance force is reduced, resulting in poor postcard passing.

In the transfer method using the conductive elastic roller, the transfer paper is inserted between the image carrier and the conductive elastic roller, and a transfer bias voltage is applied to the conductive elastic roller. The method of transferring the toner on the surface of the image carrier to a transfer sheet is problematic. However, the transfer method using such a conductive elastic roller has a problem that a back stain occurs on the transfer sheet. This is because when the toner on the image carrier is transferred to the transfer paper using the transfer roller, the transfer roller is in contact with the image carrier at a predetermined pressure in a state where there is no transfer paper. This is because the transfer roller is contaminated by the fog, and the transfer roller contaminated by the toner comes into contact with the back surface of the transferred transfer paper. Further, in a toner in which the internal additive is poorly dispersed, the fluidity is reduced, the aggregation of the toner is partially strengthened, and a hollow portion is easily generated at the time of transfer. This is more noticeable when recycling waste toner.

Further, in the transfer drum system, a transfer drum is used to align and overlap toner images of different colors, and this transfer drum is rotated at the same speed with respect to the photosensitive member, and the timing of the leading end of the image is adjusted. By matching, the mutual positions of the toner images of each color when forming a color image are matched. However, in the above configuration, since the paper must be wound around the transfer drum, the diameter of the transfer drum needs to be a certain size or more, and the structure is extremely complicated and high accuracy is required. But it was large and expensive. Strong paper such as postcards and cardboard cannot be used because they cannot be wound around the transfer drum.

On the other hand, the continuous transfer system has an image forming position corresponding to the number of colors, and it is only necessary to pass the paper through the image forming position. Therefore, such a transfer drum is not necessary. In this case, a plurality of latent image forming means such as a laser optical system for forming a latent image on a photoreceptor are required in accordance with the number of colors, and the structure is very complicated and expensive. Furthermore,
Since there are a plurality of image forming positions, it is difficult to obtain high image quality stably because the relative displacement of the image forming units of each color, the eccentricity of the rotation axis, and the displacement of the parallelism of each unit directly affect the color misregistration. there were. In particular, it is necessary to accurately perform positioning between the colors of the latent image by the latent image forming means.
As described in Japanese Patent Application Laid-Open Publication No. H11-209, there has been a problem that an image exposure system as a latent image forming means requires a considerable device and a complicated configuration.

Further, Japanese Patent Application Laid-Open No. 2-2 using an intermediate transfer material
In the example of Japanese Patent No. 12867, in order to form toner images of each color on the same photoreceptor, a plurality of developing units must be arranged around a single photoreceptor. And the photosensitive member has a belt shape that is difficult to handle. Also, if each developing device is replaced during maintenance, matching adjustment with the characteristics of the photoconductor is required, and when replacing the photoconductor, it is necessary to adjust the position with each developing device. Maintenance of the body was also difficult.

However, the intermediate transfer system does not require a complicated optical system, and can be used for rigid paper such as postcards and thick paper. The use of an intermediate transfer belt is flexible, so the transfer drum system, continuous transfer There is an advantage that the size of the device itself can be reduced as compared with the system.

It is ideal that all of the toner is transferred at the time of transfer, but some transfer residue remains. The so-called transfer efficiency is not 100%, but is generally about 75 to 90%. The transfer residual toner is scraped off by a cleaning blade or the like in a photoconductor cleaning process, and becomes waste toner.

However, in the configuration using the intermediate transfer member,
The toner undergoes at least two or more transfer steps from the photoreceptor to the intermediate transfer body and from the intermediate transfer body to the image receiving paper. In a normal single transfer copying machine, for example, 85%
Transfer efficiency, the transfer efficiency is reduced to 72% by two transfers. Further, in the case of a transfer efficiency of 75% in one transfer, 56% or about half of the toner becomes waste toner, so that the cost of the toner is increased and the volume of the waste toner box must be increased. Then, the size of the device cannot be reduced. The decrease in transfer efficiency is considered to be due to ground fogging of the opposite polarity due to poor dispersion and transfer omission.

Further, in the case of color development, the toner layer of four colors is superimposed on the intermediate transfer member, so that the toner layer becomes thick, and a pressure difference from a place where the toner layer is absent or thin is likely to occur. For this reason, the "hollow-out" phenomenon in which a part of the image is not transferred and a hole is formed due to the aggregation effect of the toner is likely to occur.
Further, if a material having a high toner releasing effect is used for the intermediate transfer member in order to surely perform cleaning when the image receiving paper is jammed, the hollow portion will be noticeable, and the image quality will be significantly reduced. Furthermore, edge development is performed for characters and lines, and the amount of toner is increased, and toner particles are aggregated by pressurization, so that hollow holes become more noticeable. In particular, it appears more remarkably in a high-humidity and high-temperature environment.

The electrophotographic apparatus described later has an image forming unit group in which a plurality of movable image forming units for forming toner images of different colors are arranged in an annular shape, and the entire image forming unit is rotated. It is a moving configuration. In addition, it is possible to replace the image forming unit and the intermediate transfer unit. When the service life expires and it is time to replace the unit, maintenance can be easily performed by replacing the unit. Can be obtained. However, since the image forming unit orbits itself, the cleaned waste toner temporarily and repeatedly adheres to the photoconductor, and also separates from and adheres to the developing roller, so that the photoconductor is easily damaged or filmed. However, if the charge rising property is poor in the early stage of development, initial fog is induced.

In fixing the four-color toner image, it is necessary to mix color toners. At this time,
When toner melting failure occurs, light is scattered on the surface or inside of the toner image, the original color tone of the toner dye is damaged, and light does not enter the lower layer in the overlapping part,
Color reproducibility decreases. Therefore, it is a necessary condition that the toner has a perfect melting property and has a light-transmitting property so as not to hinder the color tone. In particular, the need for optical transparency on OHP paper is increasing due to an increase in presentation opportunities in color.

However, with such a resin composition, the offset resistance is reduced when the melting characteristics are to be further improved,
Since not all of the toner is fixed to the paper but the toner adheres to the surface of the fixing roller to cause offset, a large amount of oil or the like must be applied to the fixing roller, which complicates handling and the configuration of equipment.

There is also a method of improving the anti-offset property by adding a release agent such as polypropylene or polyethylene. However, a large amount must be added, and the dispersibility of the binder in the above-mentioned sharp melt binder resin is remarkable. The color reproducibility is reduced.

Further, JP-A-5-119509 and JP-A-8-220808 report that a large amount of carnauba wax is added to suppress color turbidity and obtain excellent fixing properties and offset resistance. Has been made.

However, as described above, mere addition of carnauba wax or the like induces occurrence of film fogging on the ground fog, the photosensitive member, the developing roller, and the intermediate transfer member and the transfer failure due to the dispersion failure. Further, these phenomena become more remarkable in the waste toner recycling process.

Further, Japanese Patent Application Laid-Open Nos.
In JP-A-333584, a configuration in which a compound having a fluorine element is added has been proposed. It is stated that the releasability can be further improved by this. However, by adding this material, the negative charging property becomes too strong, and when used repeatedly for a long time, the toner is overcharged, resulting in a reduction in image density and a reduction in transferability. In particular, it occurs more remarkably when used under low temperature and low humidity. Further, aggregation between toner particles tends to be strong, which causes vertical streaks on the developing roller, missing during transfer, and a decrease in transfer rate. In particular, it occurs more remarkably in a four-color full-color image.

The toner must satisfy the above-mentioned problems comprehensively.

In view of the above problems, an object of the present invention is to provide a toner and an electrophotographic apparatus which improve the dispersibility of a colorant in a binder resin and have a uniform charge distribution.

Another object of the present invention is to provide an oilless fixing full-color electrophotographic toner and an electrophotographic apparatus which do not apply oil.

Even when used in a contact-type one-component developing method, thermal fusion or aggregation of toner does not occur, and even when a high-performance binder resin is used, the additive can be used without deteriorating the resin characteristics. It is an object of the present invention to provide a toner and an electrophotographic apparatus capable of improving the dispersibility of toner and maintaining stable developing property.

It is also an object of the present invention to provide a toner and an electrophotographic apparatus which are capable of satisfying both the fixing property and the anti-offset property, and have excellent dispersibility, stable charging property and high image quality even in models having a wide range of different processing speeds. With the goal.

It is another object of the present invention to provide a toner and an electrophotographic apparatus which can prevent dropout or scattering at the time of transfer by an electrophotographic method using a conductive elastic roller or an intermediate transfer member and can obtain high transfer efficiency. I do.

It is another object of the present invention to provide a toner and an electrophotographic apparatus which can prevent filming of a photoreceptor and an intermediate transfer member even during long-term use under high humidity.

Further, even if the waste toner is recycled, the charge amount and the fluidity of the developer do not decrease, the coagulation does not occur, the life is extended, the recycling development is enabled, the prevention of global environmental pollution and the resource It is an object of the present invention to provide a toner and an electrophotographic apparatus which enable reuse of a toner.

[0049]

In view of the above-mentioned problems, the toner according to the present invention comprises a toner base comprising at least a fluorine-containing polymer, a polyester resin having an acid value of 10 or more, and a colorant, at least having a positive chargeability. Wherein an external additive comprising hydrophobic silica having the formula:

The toner according to the present invention comprises a toner base comprising at least a fluorine-containing polymer, a polyester resin having an acid value of 10 or more and a colorant, at least a hydrophobic silica having a positive charge and a negative charge. It is characterized in that an external additive made of hydrophobic silica having properties is added.

The toner according to the present invention comprises a toner base comprising at least a fluorine-containing polymer, a polyester resin having an acid value of 10 or more and a colorant, and at least a hydrophobic silica having a positive charge property and a low resistance. It is characterized in that an external additive composed of a metal oxide fine powder is added.

The toner according to the present invention comprises a toner base comprising at least a fluorine-containing polymer, a polyester resin having an acid value of 10 or more and a colorant, and at least hydrophobic silica having a positive charge property and an average particle size. Diameter 0.02-
4 μm, BET specific surface area by nitrogen adsorption of 0.1 to 10
It is characterized in that an external additive comprising titanate-based fine powder or zirconiaate-based fine powder of 0 m ² / g is added.

Further, the constitution of the toner according to the present invention is such that the charge control agent comprising a metal complex of a salicylic acid metal complex and / or a metal complex of a benzylic acid derivative is contained in an amount of 0.5 to 4 parts by weight per 100 parts by weight of the toner base. .

Furthermore, the toner according to the present invention has a low-resistance metal oxide fine powder having an average particle size of 0.02 to 2 μm,
BET specific surface area by nitrogen adsorption of 0.1 to 100 m ² /
g, a titanium oxide fine powder, an aluminum oxide fine powder, a strontium oxide fine powder, a tin oxide fine powder, a zirconia fine powder, a magnesium oxide fine powder, and an indium oxide fine powder having an electric resistivity of 10 ⁹ Ωcm or less. It is composed of one or more metal oxide fine powders.

Further, the constitution of the toner according to the present invention is such that the low-resistance metal oxide fine powder has an average particle size of 0.02 to 2 μm,
It is composed of titanium oxide and / or silica oxide fine powder surface-coated with a mixture of tin oxide and antimony having a BET specific surface area of 1 to 200 m ² / g by nitrogen adsorption.

Further, the constitution of the toner according to the present invention is such that the hydrophobic silica is selected from dimethyl silicone oil, methylphenyl silicone oil, alkyl-modified silicone oil, fluorine-modified silicone oil, amino-modified silicone oil and epoxy-modified silicone oil. It has a BET specific surface area of 30 to 350 m ² / g by nitrogen adsorption treated with at least one or more types.

Further, the constitution of the toner according to the present invention is such that titanate-based fine powder or zirconiaate-based fine powder is prepared by a hydrothermal method or an oxalate pyrolysis method.

Further, the constitution of the toner according to the present invention is such that the polymer containing fluorine has a specific gravity of 1.0 at 25 ° C.
5 or more, in the differential scanning calorimetry, the tangent melting point temperature at the time of temperature rise (the intersection of the tangent of the rising curve at the start of heat absorption at the time of temperature rise and the tangent of the curve toward the peak after the rise is defined as the tangential melting point temperature) 70 to 140 ° C., the peak temperature is 73 to 148 ° C., and the difference between the peak temperature and the tangential melting point temperature is 2
It is less than 0K.

Further, in the constitution of the toner according to the present invention, the fluorine-containing polymer has an average particle diameter of 1 to 11 μm.

Further, the constitution of the toner according to the present invention is such that 0.3 <FP / TP <0.9, where FP is the average particle diameter of the polymer containing fluorine and TP is the average particle diameter of the toner. is there.

Further, the constitution of the toner according to the present invention is such that the fluorine-containing polymer comprises a copolymer of olefin and tetrafluoroethylene.

Further, in the constitution of the toner according to the present invention, the fluorine-containing polymer is composed of jojoba oil or meadowfoam oil to which partial fluorine is added or extremely fluorine is added.

Further, in the constitution of the toner according to the present invention, the fluorine-containing polymer is a copolymer of tetrafluoroethylene and an acrylate represented by the formula (3) and / or (4). Things.

[0064]

Embedded image

[0065]

Embedded image

Further, the constitution of the toner according to the present invention is such that the fluorine-containing polymer is a copolymer of tetrafluoroethylene, an olefin and the acrylate represented by the above formula (3) and / or (4). It consists of coalescence.

[0067]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present embodiment, a binder resin as a constituent material of a toner, a coloring agent, a fixing aid, and other internal additives such as a charge control agent that is added as required are uniformly mixed by a preliminary dry method. Mix, melt and knead with heat to disperse the colorant and internal additives in the binder resin. After cooling, the external additives are added to the toner base, which is colored fine particles having a predetermined particle size distribution by pulverization and classification. A toner is created by the addition and mixing process.

Digital high image quality, high color reproduction
In order to achieve both high translucency and anti-offset properties without using an oil for preventing offset in the fixing roller, a sharp melt binder resin having a small molecular weight distribution and a low molecular weight component has been used. With this configuration, light transmission can be ensured, but since offset occurs, it was necessary to apply oil to the fixing roller. In addition, polypropylene and
Attempts have also been made to improve the releasability by adding a release agent such as polyethylene. However, it is very difficult to disperse the sharp melt binder resin, especially polyester resin, by simply adding it.Fog, filming on the photoreceptor and developing roller, deterioration of the charge rise, and the amount of charge during repeated use Problems such as a decrease in image density due to the decrease occur.

However, by adding a fluorine-containing polymer as a fixing aid, not only the offset can be prevented without applying oil to the fixing roller, but also the dispersibility in the resin can be made uniform. Filming on the photoconductor can be prevented. In addition, even if it is repeatedly used, the charge does not decrease, and a stable image can be output.

However, by adding this material, the negative chargeability becomes too strong, and when used repeatedly for a long time, the toner is overcharged, and the image density and transferability are reduced. In particular, it occurs more remarkably when used under low temperature and low humidity. Further, aggregation between toner particles tends to be strong, which causes vertical streaks on the developing roller, missing during transfer, and a decrease in transfer rate. In particular, it occurs more remarkably in a four-color full-color image.

Therefore, by using a hydrophobic silica having a positive charge property as an external additive in combination with the external additive, it is possible to suppress cohesion, prevent omission during transfer, and continuously operate under low temperature and low humidity. It has been found that the image characteristics can be stabilized in use. Furthermore, by using a method of mixing with negatively chargeable silica, using a method of mixing with a low-resistance metal oxide, and mixing and using a metal salt-based fine powder,
The stability is improved.

The positively chargeable silica is treated with aminosilane, amino-modified silicone oil, or epoxy-modified silicone oil.

In order to further enhance the hydrophobic treatment, it is preferable to use a combination of treatment with hexamethyldisilazane, dimethyldichlorosilane or another silicone oil. For example, it is preferable to treat with at least one of dimethyl silicone oil, methylphenyl silicone oil, and alkyl-modified silicone oil.

As the silane coupling agent,
Dimethyldichlorosilane, trimethylchlorosilane, allyldimethylchlorosilane, hexamethyldisilazane,
Examples include allylphenyldichlorosilane, benzylmethylchlorosilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, divinylchlorosilane, and dimethylvinylchlorosilane. The silane coupling agent treatment is a dry process in which the vaporized silane coupling agent is reacted with a cloud of fine powder by stirring or the like, or a wet process in which the silane coupling agent in which the fine powder is dispersed in a solvent is dropped. Processed according to the law.

As the negatively chargeable silica, those treated with silicone oil such as dimethyl silicone oil, methylphenyl silicone oil, fluorine-modified silicone oil, and alkyl-modified silicone oil are preferably used.

The treatment may be carried out by mixing the silica fine powder and the silicone oil-based material with a mixer such as a Henschel mixer, by spraying the silicone oil-based material onto silica, or by dissolving the silicone oil-based material in a solvent. After dispersion and mixing with fine silica powder, there is a method of preparing by removing the solvent. Preferably, 0.1 to 8 parts by weight of a silicone oil-based material is blended with respect to 100 parts by weight of silica.

At this time, silica is converted into BET by nitrogen adsorption.
A hydrophobic silica having a specific surface area of 30 to 350 m ² / g is externally added to the toner matrix. More preferred specific surface area is 50 to
300 m ² / g, more preferably 80 to 250 m ² / g
Is preferably within the range. When the specific surface area is less than 30 m ² / g, the fluidity of the toner does not improve and the storage stability decreases. When the specific surface area is larger than 350 m ² / g, aggregation of silica is deteriorated and uniform external addition becomes difficult. The hydrophobic silica is used in an amount of 0.1 per 100 parts by weight of the toner base particles.
1 to 5 parts by weight, preferably 0.2 to 3 parts by weight is blended. If the amount is less than 0.1 part by weight, the fluidity of the toner cannot be improved.

The mixing ratio of the positively chargeable silica and the negatively chargeable silica is preferably 100: 0 to 55:45. The ratio is more preferably 95: 5 to 60:40, and further preferably 90:10 to 65:35. If the ratio of the negatively chargeable silica exceeds 45, overcharging becomes severe and solid followability deteriorates.

The charge amount of silica is measured by a blow-off method of triboelectric charging with a non-coated ferrite carrier. Under an environment of 25 ° C. and 45% RH, 50 g of the carrier and 0.1 g of silica were mixed in a 100 ml polyethylene container, and the mixture was rotated vertically at a speed of 100 min ⁻¹ for 5 minutes.
After stirring for 0.3 minutes, 0.3 g was collected and nitrogen gas 1.96 ×
Blowing was performed at 10 ⁴ (Pa) for 60 seconds.

For the positively chargeable silica, the 5-minute value is +100 to +
At 800 μC / g, the value of 30 minutes is +50 to +400 μC
/ G. Silica having a charge amount at 30 minutes value of 40% or more of a charge amount at 5 minutes value is preferable. If the rate of decrease is large, the change in the charge amount during long-term continuous use is large, and a constant image cannot be maintained.

In the case of negatively chargeable silica, the 5-minute value is -100 to-
At 800 μC / g, the value for 30 minutes is −50 to −400 μC
/ G. The silica having a high charge amount can exhibit its function with a small amount of addition.

Further, as the metal-free oxide fine powder having a low resistance value, the average particle diameter is 0.02 to ² μm, the BET specific surface area by nitrogen adsorption is 0.1 to 100 m ² / g, and the electric resistivity is 10 ⁹ Ωcm. Metal oxide fine powder comprising at least one of the following titanium oxide fine powder, aluminum oxide fine powder, strontium oxide fine powder, tin oxide fine powder, zirconia fine powder, magnesium oxide fine powder, and indium oxide fine powder. By externally adding the powder,
The characteristics are more stable.

More preferably, the average particle size is from 0.02 to 0.1.
8 μm, BET specific surface area by nitrogen adsorption of 1.0 to 85
m ² / g, more preferably an average particle size of from 0.02 to 0.1 g / m ² .
1 μm, BET specific surface area by nitrogen adsorption is 8 to 85 m ²
/ G, and still more preferably, an average particle size of 0.02 to 0.2.
06 μm, BET specific surface area by nitrogen adsorption is 10 to 85
m ² / g.

During continuous long-term use, the frictional charge between the toner and the supply roller is overcharged, thereby reducing the amount of toner transported on the developing roller and deteriorating the solid tracking ability. The effect that the image density and the solid followability can be maintained is obtained. In particular, it works more effectively in a supply roller using a urethane resin.

Further, the transferability is improved, the cohesiveness of the toner is suppressed, the omission during transfer can be prevented, the image characteristics can be stabilized in continuous use under low temperature and low humidity, and the effect of maintaining the image density can be obtained.

When the average particle size is smaller than 0.02 μm and the BET specific surface area by nitrogen adsorption is larger than 100 m ² / g, the cohesiveness is strong and uniform dispersion cannot be performed at the time of the external addition treatment, so that the above effects cannot be exhibited. When the electrical resistivity is larger than 10 ⁹ Ωcm, the above effect is reduced. If the average particle size is larger than 2 μm and the BET specific surface area due to nitrogen adsorption is smaller than 0.1 m ² / g, detachment from the toner matrix becomes severe, affecting the durability and causing greater damage to the photoreceptor.

Further, a metal oxide fine powder composed of titanium oxide and / or silica oxide fine powder surface-coated with a mixture of tin oxide and antimony having a BET specific surface area of 1 to 200 m ² / g by nitrogen adsorption is added. As a result, the frictional charge between the toner and the supply roller is overcharged during continuous long-term use, and the toner following amount is reduced on the developing roller and the tracking ability is deteriorated. The effect of improving the followability that can be maintained can be obtained. In particular, it works more effectively in a supply roller using a urethane resin.

If it is larger than 200 m ² / g, the mixing process cannot be performed uniformly, and if it is smaller than 1 m ² / g, detachment from the toner increases and the durability of the toner decreases.

By using this in combination with the binder resin and the fixing aid of the present configuration, it is possible to suppress unevenness of layer formation on the developing roller due to contamination, and furthermore, it is possible to prevent fog during development and use for a long period of time. It has been found that it is possible to prevent a decrease in concentration at the time.

Further, better properties can be obtained by externally mixing and adding a metal salt fine powder together with hydrophobic silica to the toner matrix. Metal acid comprising at least one of titanate-based fine powder or zirconia-based fine powder having an average particle size of 0.02 to 4 μm and a BET specific surface area by nitrogen adsorption of 0.1 to 100 m ² / g. By adding the salt fine powder to the toner matrix, the chargeability can be further stabilized, the waste toner recyclability can be improved, and the transferability can be improved. In particular, in a system to which a fixing aid has been added, overcharging tends to occur during long-term continuous use under low temperature and low humidity, which causes a reduction in image density. The effect of preventing this is exhibited. Further, it is effective for stabilizing the charge at the time of recycling the waste toner, preventing filming, and maintaining the charge amount at the time of continuous use under low humidity.

The materials used are SrTiO ₃ , BaTi
O ₃ , MgTiO ₃ , AlTiO ₃ , CaTiO ₃ , PbT
iO ₃ , FeTiO ₃ , SrZrO ₃ , BaZrO ₃ , Mg
ZrO ₃ , AlZrO ₃ , CaZrO ₃ , PbZrO ₃ , S
rSiO ₃ , BaSiO ₃ , MnSiO ₃ , CaSiO ₃ ,
MgSiO ₃ .

[0092] Further, by producing these metal salt fine powders by a hydrothermal method or an oxalate pyrolysis method, the effect is further enhanced. This is because the generated material has a uniform particle size distribution and a shape closer to a sphere than an amorphous shape. If the average particle size is smaller than 0.02 μm and the BET specific surface area by nitrogen adsorption is larger than 100 m ² / g, the particles are strongly aggregated and the dispersibility is reduced. Average particle size is larger than 4 μm, BET specific surface area by nitrogen adsorption is 0.1 m ² / g
If it is smaller, damage to the photoreceptor by particles increases.

The method of synthesizing the fine powder under the hydrothermal conditions includes hydrothermal oxidation, hydrothermal precipitation, hydrothermal synthesis, hydrothermal dispersion, hydrothermal crystallization, hydrothermal hydrolysis, There are a hydrothermal attrider mixing method, a hydrothermal mechanochemical method and the like. Preferred are hydrothermal oxidation, hydrothermal precipitation, hydrothermal synthesis, hydrothermal dispersion and hydrothermal hydrolysis.

The fine powder synthesized by this method can be obtained as a spherical fine powder with little agglomeration, narrow particle size distribution, and good fluidity. Therefore, when externally added and mixed to the toner, the toner has good dispersibility and adheres uniformly to the toner. And since the shape is spherical, there is no unnecessary damage to the photoreceptor. In addition, since it shows appropriate rolling in cleaning, it improves the cleaning performance without increasing the coefficient of friction, and is particularly effective in preventing filming when using a toner having a small particle diameter to which a fixing aid is added. Can be The amount of the metal oxide fine powder and / or metal salt fine powder added to the toner is 0.1 to 5 parts by weight based on 100 parts by weight of the toner base.
Parts by weight are preferred. When it is less than 0.1, the function is not exhibited, and when it is more than 5, the moisture resistance is deteriorated.

As a polymer containing fluorine, 25 ° C.
Tangent melting point temperature at the time of temperature rise in differential scanning calorimetry (the tangent to the tangent of the rising curve at the end of heat absorption at the time of temperature rise and the tangent of the curve toward the peak after the temperature rise) 70-140
It is preferable that the peak temperature is 73C to 148C, and the difference between the peak temperature and the tangential melting point temperature is 20K or less.

More preferably, the specific gravity at 25 ° C. is 1.08 or more, and the tangential melting point temperature at the time of temperature rise is 75 to 135.
° C, the peak temperature is preferably 78 ° C to 143 ° C, and the difference between the peak temperature and the tangential melting point temperature is preferably 18K or less.

More preferably, the specific gravity at 25 ° C. is 1.1 or more, the tangential melting point temperature at the time of temperature rise is 78 to 132 ° C.,
Preferably, the peak temperature is 81 ° C to 140 ° C, and the difference between the peak temperature and the tangential melting point temperature is 16K or less.

When the specific gravity is smaller than 1.05, the fluorine ratio decreases, and the anti-offset effect decreases.

When the tangential melting point temperature is lower than 70 ° C., the storage stability is deteriorated and thermal aggregation is liable to occur. In addition, filming occurs on the photoconductor, the intermediate transfer member, and the developing roller. If the tangential melting point temperature is higher than 140 ° C., the anti-offset effect is reduced, the dispersibility is reduced, the amount of waste toner increases, and fog increases.

When the peak temperature is lower than 73 ° C., the storage stability is deteriorated and thermal aggregation is liable to occur. In addition, filming occurs on the photoconductor, the intermediate transfer member, and the developing roller. When the peak temperature is higher than 148 ° C., the anti-offset effect decreases, the dispersibility decreases, the amount of waste toner increases, and fog increases.

If the difference between the peak temperature and the tangential melting point temperature is larger than 20 K, a large amount of low-temperature melting components below the peak temperature will be contained, so that the dispersibility during kneading will decrease, the amount of waste toner will increase, and the fog will be reduced. Cause an increase. In addition, filming easily occurs on the photosensitive member, the intermediate transfer member, and the developing roller.

Examples of the fluorine-containing polymer include copolymers of olefins and tetrafluoroethylene, jojoba oil or meadowfoam oil partially or fluoridated, or tetrafluoroethylene and / or
A copolymer of an acrylic ester represented by the chemical formula (6) and an acrylic ester copolymer represented by the chemical formula (5) and / or the chemical formula (6) are compatible with tetrafluoroethylene and an olefin. They may be used alone or as a mixture.

[0103]

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[0104]

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Meadowfoam oil, original name Limnanthus alba, is a triglyceride obtained by collecting and pressing meadowfoam seeds belonging to the family Limnantaceae of the order Pectinidae. It contains a large amount of eicosenoic acid and contains long-chain fatty acids of C20 or more. Among the 22: 1 fatty acids, there are erucic acid and its isomers. Most of the unsaturated fatty acids are monoenoic acids, have a low degree of unsaturation, and have good oxidation stability.

Jojoba oil is a wax wax of an unsaturated higher fatty acid and alcohol collected from jojoba berries. The carbon number is almost C40 and C42.
The crude wax obtained by pressing is liquid and becomes colorless and transparent upon purification.

These fixing aids have a different chemical structure from polyethylene wax and polypropylene wax which have been generally used in the past, and have a unique excellent effect.

The fluorine-added meadowfoam oil is obtained by adding fluorine to meadowfoam oil to convert unsaturated bonds into saturated bonds. Those with extreme or partial fluorine addition are preferred.

The fluoridated jojoba oil is obtained by adding fluorine to jojoba oil to convert unsaturated bonds into saturated bonds. Those with extreme or partial fluorine addition are preferred.

The addition amount is preferably 0.1 to 20 parts by weight based on 100 parts by weight of the toner. If the amount is less than 0.1 part by weight, the effects of fixing property and anti-offset property cannot be obtained,
If the amount is larger than 0 parts by weight, storage stability is reduced, and there are problems in pulverizability such as excessive pulverization.

Further, it can be used in combination with other components. For example, carunauba wax, candelilla wax, lanolin, wood wax, beeswax, ozokerite, ceresin, plant wax such as rice wax, polyethylene, polyolefin wax such as polypropylene, fatty acid amide, stearic acid, palmitic acid, lauric acid, Higher fatty acids such as aluminum stearate, barium stearate, zinc stearate, zinc palmitate and the like, and derivatives thereof such as metal substances and esters thereof can be used alone or in combination of two or more kinds. In particular, the melting point is 70-9
The use of carnauba wax at 5 ° C. further improves fixing characteristics. The addition amount is preferably 1 to 10 parts by weight.

The toner containing these acts as a fixing aid to improve fixability, enhances adhesion to paper, reduces frictional resistance on the image surface on paper, and removes toner from paper by abrasion. The effect of suppressing peeling and improving fixability is obtained. Further, it is possible to further improve the translucency of the color toner requiring the translucency and achieve compatibility with the offset resistance.

Further, a polyester resin is used as a binder resin of the toner, and the acid value of the polyester resin is 1
By setting it to 0 or more, the chargeability is stabilized. In addition, toner aggregation can be prevented, and filming on the photoreceptor, the intermediate transfer member, and the developing roller can be prevented even when used continuously for a long period of time. This is because the dispersion of the fixing aid at the time of kneading can be made better, and it is considered that there is an effect that the charge can be maintained at a certain level by the acid value of the positively chargeable silica and the resin. If it is smaller than 10, fog tends to increase.

The acid value is preferably from 10 to 100, more preferably from 15 to 80. More preferably, 20 to 50
It is. If it is smaller than 10, the dispersibility of the fixing aid decreases. If it exceeds 100, the moisture resistance decreases.

By using a binder resin in combination with a polyester resin having a certain high molecular weight component, high translucency and high color reproducibility can be ensured, and even if a fixing oil is not required, a higher temperature range can be attained. Created a configuration that can extend the offset width up to.

As the binder resin suitably used in the present embodiment, a polyester resin obtained by polycondensation of an alcohol component and a carboxylic acid component such as carboxylic acid, carboxylic acid ester and carboxylic anhydride is preferably used. .

Examples of the divalent carboxylic acid or lower alkyl ester include aliphatic dibasic acids such as malonic acid, succinic acid, glutaric acid, adipic acid and hexahydrophthalic anhydride.
Maleic acid, maleic anhydride, fumaric acid, itaconic acid,
Examples thereof include aliphatic unsaturated dibasic acids such as citraconic acid, aromatic dibasic acids such as phthalic anhydride, phthalic acid, terephthalic acid and isophthalic acid, and methyl esters and ethyl esters thereof. Of these, aromatic dibasic acids such as phthalic acid, terephthalic acid, and isophthalic acid, and lower alkyl esters thereof are preferred.

As the carboxylic acid component having a valency of 3 or more, 1,
2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid,
1,2,4-naphthalenetricarboxylic acid, 1,2,4-
Butanetricarboxylic acid, 1,2,5-hexatricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, Examples thereof include pyromellitic acid, empole trimer acid, acid anhydrides thereof, and alkyl (C1 to C12) esters.

As the dihydric alcohol, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butylene glycol, 1,4
Diols such as butylene glycol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct, glycerin, trimethylolpropane, trimethylolethane, etc. Triols and mixtures thereof can be exemplified. Among them, neopentyl glycol, totimethylolpropane, bisphenol A ethylene oxide adduct, bisphenol A
Propylene oxide adducts are preferred.

Examples of the trihydric or higher alcohol component include sorbitol, 1,2,3,6-hexanetetrol,
4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-
Butanetriol, 1,2,5-pentanetriol,
Glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene and the like can be mentioned.

For the polymerization, known polycondensation, solution polycondensation and the like can be used. As a result, a good toner can be obtained without impairing the PVC mat resistance and the color of the color material of the color toner.

The proportion of the polyhydric carboxylic acid and the polyhydric alcohol to be used is generally 0.8 to 1.4 in terms of the ratio of the number of hydroxyl groups to the number of carboxyl groups (OH / COOH).

In the present embodiment, a charge control agent is added to the binder resin for the purpose of controlling the charge of the toner. Preferred materials include salicylic acid metal complexes, metal complexes of benzylic acid derivatives,
A phenylborate quaternary ammonium salt is preferably used. The metals are preferably zinc, nickel, copper and chromium.
The addition amount is preferably 0.5 to 5 parts by weight based on 100 parts by weight of the binder resin. More preferably, it is 1 to 4 parts by weight, and still more preferably 3 to 4 parts by weight.

Examples of the pigment used in this embodiment include carbon black, iron black, graphite, nigrosine, metal complexes of azo dyes, C.I. I. Pigment Yellow 1,
Acetoacetic acid arylamide monoazo yellow pigments such as 3,74,97,98; I. Pigment Yellow 1
Acetoacetic acid arylamide disazo yellow pigments such as 2,13,14,17; I. Solvent yellow 19,
77, 79, C.I. I. Disperse Yellow 164,
C. I. Pigment Red 48, 49: 1, 53:
Red pigments such as 1,57,57: 1,81,122,5,
C. I. Red dyes such as Solvent Red 49, 52, 58, 8; I. Pigment Blue 15: 3 or the like or a blue dye / pigment of phthalocyanine or a derivative thereof
It is blended in more than one kind. The addition amount is preferably 3 to 8 parts by weight based on 100 parts by weight of the binder resin.

For the purpose of achieving higher resolution, it is required that the toner particle size be made smaller and the particle size distribution be sharper. At this time, the relationship between the particle size of the fixing aid added to the toner and the particle size of the toner contributes to the developing property, the charging property, and the filming property. In other words, if the fixing aid does not have a particle size in a certain range with respect to the toner particle size, overcharging occurs more remarkably, causing problems such as toner aggregation, image density reduction under low humidity, and photoreceptor filming. Or the offset resistance does not work effectively.

Therefore, it is necessary to set the particle size distribution to a certain set value. That is, if the volume average particle diameter of the toner is TP and the volume average particle diameter of the fixing aid is FP, FP / TP is 0.1.
That is, the particle diameter is set in a range that satisfies 3 or more and 0.9 or less.

If it is smaller than 0.3, the anti-offset effect at the time of fixing is reduced, and the non-offset temperature range becomes narrow. If it is larger than 0.9, overcharging occurs more remarkably, causing toner aggregation and lowering of image density under low humidity.

Further, filming on the photoconductor becomes easy due to the load when cleaning the untransferred toner remaining on the photoconductor at the time of transfer. Further, when the toner layer is formed in a thin layer on the developing roller, the contamination of the roller becomes more severe.
Further, when the waste toner is recycled, the fixing aid detached from the toner tends to remain in the untransferred toner, and when this is returned to the development again, the charge varies in the developer and the image quality cannot be maintained. Further, the toner is overcharged due to repeated use for a long time, and the image density is reduced.

The volume average particle size of the toner is 3 to 11
μm, preferably 3 to 9 μm, more preferably 3 to 6 μm.
μm. When it is larger than 11 μm, the resolution is reduced and high image quality is not obtained. When it is smaller than 3 μm, toner aggregation is increased and background fog is increased.

The volume average particle diameter of the fixing aid is 1 to 10 μm.
, Preferably 2 to 8 μm, more preferably 2 to 5 μm
It is.

The variation coefficient of the volume particle size distribution of the toner is 1
Preferably, the coefficient of variation of the number particle size distribution is 5 to 35%, and the coefficient of variation of the number particle size distribution is 20 to 40%. More preferably, the variation coefficient of the volume particle size distribution is 15 to 30% and the variation coefficient of the number particle size distribution is 2
0 to 35%, more preferably, the variation coefficient of the volume particle size distribution is 15 to 25%, and the variation coefficient of the number particle size distribution is 20 to 3
0%.

The coefficient of variation is obtained by dividing the standard deviation of the toner particle size by the average particle size. This is based on the particle size measured using a Coulter counter (Coulter). The standard deviation is obtained by calculating the square of the difference from the average value of each measured value when measuring n particle systems (n-
It is expressed by the square root of the value divided by 1).

In other words, the coefficient of variation refers to the degree of spread of the particle size distribution, and the coefficient of variation of the volume particle size distribution is 15%.
If it is less than 10%, or if the coefficient of variation of the number particle size distribution is less than 20%, it is difficult in terms of productivity and causes an increase in cost.
If the coefficient of variation of the volume particle size distribution is larger than 35% or the coefficient of variation of the number particle size distribution is larger than 40%, when the particle size distribution becomes broad, the cohesiveness of the toner becomes strong and filming on the photoreceptor occurs. Easier to do.

When the particle size of the toner is reduced and the distribution width is kept within a certain value, it is necessary to add a certain amount of a fluidizing agent in order to maintain fluidity. Poor dispersibility in kneading also affects fluidity, lowering image quality, preventing good recycling of waste toner, lowering transfer efficiency, and making it difficult to form a uniform toner layer on the developing roller. become. Further, in the two-component developing system, the miscibility with the carrier is reduced, the toner density control becomes unstable, the charge distribution becomes uneven, and the image quality is reduced. Therefore, it is necessary to add more silica that can impart high fluidity to a toner having a smaller particle size.

Therefore, when the particle size of the toner is reduced and the distribution width based on the coefficient of variation is kept within a certain value, the characteristics are more suitably applied to the small particle size toner by the binder resin and the fixing aid of the present configuration. It can be stabilized.

In a developing method in which a thin layer of toner is uniformly regulated by a rigid or elastic blade on a developing roll and frictionally charged to develop an electrostatic latent image, a developing sleeve or blade is contaminated to form a toner layer. May cause unevenness, which may lead to image defects.

In this embodiment, a transfer material is inserted between the image carrier and the conductive elastic roller, and a transfer bias voltage is applied to the conductive elastic roller to transfer the toner image on the image carrier to the electrostatic roller. It is suitably used in an electrophotographic apparatus having a toner transfer system for transferring to a transfer material by force. This is because such a toner transfer system is a contact transfer, so mechanical force other than electric force acts on the transfer,
Reverse polarity toner attached to the surface of the photoreceptor that should not be transferred is transferred, or toner adhered to the surface of the photoreceptor when paper is not passed will contaminate the transfer roller surface and contaminate the transfer paper back surface. There are things that can happen.

Therefore, the use of the fluorine-containing compound of the present embodiment can prevent the offset property in the fixing without using oil, and suppresses the aggregation of the toner by adding the positively chargeable silica or the low-resistance metal oxide fine powder. It is possible to prevent overcharging, stabilize the charging property, prevent hollowing during transfer, and obtain high transfer efficiency. Further, the occurrence of filming on the intermediate transfer member and the photosensitive member can be prevented, and the transfer paper can be prevented from being contaminated by unnecessary toner particles. In addition, since filming of toner and free silica on the transfer roller surface can be prevented,
Image defects caused by retransfer of toner and free silica from the surface of the transfer roller to the surface of the photoreceptor can also be prevented. The characteristics can be more suitably stabilized with respect to the small particle size toner.

In the present embodiment, the toner is preferably used in an electrophotographic apparatus having a waste toner recycling system for collecting the toner remaining on the image carrier after the transfer process into the developing device and reusing the toner in the developing process. Since the waste toner is reused in the development, the overcharged toner returns to the development, and a phenomenon occurs in which the charge is fluctuated and the image density is reduced by continuous and repeated use. Further, since the toner is easily aggregated, clogging is easily caused in the transport pipe.

Further, a compound having fluorine released by a mechanical shock inside the cleaning device, a transport pipe connecting the cleaning device and the developing device, and a developing device during the recovery from the cleaning device to the developing device is formed. It may fall off or cause filming on the photoreceptor.

Therefore, the use of the fluorine-containing compound of the present embodiment can prevent the offset property in the fixing without using oil, and suppress the aggregation of the toner by adding the positively chargeable silica or the low-resistance metal oxide fine powder. It does not cause clogging in the transport tube, prevents overcharging, stabilizes charging properties, and maintains stable image density and fogging even under continuous low-temperature and low-humidity conditions. Filming can be prevented.

It is also preferably used for the one-component developing method. When a supply roller made of urethane resin and a developing roller made of silicon resin or urethane resin are fixed to a fixed amount (0.1
１1 mm) to supply toner to the developing roller from the supply roller, and form a thin layer of toner on the developing roller by using an elastic rubber or metal stainless steel doctor blade to contact the photosensitive member. It is suitably used in a developing method for forming a toner image by applying DC or AC in contact or non-contact. At this time, the supply roller and the developing roller are rotated in the same direction, and the peripheral speed of the developing roller and the supply roller is set to 1: 1.
A configuration is adopted in which the developing roller is advanced at a ratio of 0.8 to 0.2. The developing roller is 9.8 × 10 ^2-
The electrostatic latent image on the photoreceptor is developed by being pressed at a pressure of 9.8 × 10 ⁴ (N / m ² ). The elastic blade is 5 × 10 ³
A toner layer is formed by pressing against the developing roller at a pressure of about 5 × 10 ⁵ (N / m ² ).

Further, in order to control the amount of toner supplied from the toner reservoir to the amount of toner transported on the developing roller when the toner is transported onto the developing roller, a sponge-like supply roller made of urethane resin or the like is used. A configuration provided in contact with the developing roller is adopted.

This is an effective means for regulating the toner transport amount to a constant amount. However, when the amount of toner transported on the developing roller decreases during long-term continuous use, or when a solid black image is taken, one round of the developing roller is developed with a high density. Is not conveyed, and the density rapidly lowers, which may deteriorate the solid followability. When the charge amount of the toner on the developing roller was measured by a suction method, it was found that the charge amount was greatly reduced.
Therefore, measures were taken to increase the charge amount by increasing the amount of the charge control agent or silica, but the image density tended to decrease further. Further, in the toner to which the fluorine-containing compound was added, the density was further reduced.

In further pursuit, the charge amount of the toner on the supply roller portion has increased greatly. That is, the decrease in the image density does not mean that the charge amount of the toner has decreased, but the supply amount before the toner is supplied to the developing roller. This is because the roller section has been charged up and the supply capacity from the supply roller to the developing roller has been reduced. However, if the material composition is changed so as to reduce the charge of the toner, the scattering of the toner around the developing device increases. Therefore, a configuration that can secure the image density while preventing toner scattering is required.

Thus, the use of the fluorine-containing compound of the present embodiment can prevent the offset property in the fixing without using oil, and suppress the aggregation of the toner by adding the positively chargeable silica or the low-resistance metal oxide fine powder. It has been found that overcharging can be prevented and the charging property can be stabilized, and that image density and fog can be stably maintained even when used continuously and repeatedly at low temperature and low humidity. This prevents overcharging of the toner at the supply roller with positively chargeable silica or inorganic fine powder having a low resistance value, and also suppresses toner scattering by containing a toner base and an externally chargeable external additive. Becomes Further, the image density at the time of continuous use can be stabilized, and the solid followability can be improved.

Further, heat fusion of toner is likely to occur due to rubbing between the supply roller and the developing roller. In addition, scratches are formed on the developing roller, which appear as image noise. If the chargeability of the toner fluctuates during long-term use, the supply of the toner from the supply roller to the developing roller becomes unstable, resulting in a decrease in image density and fogging. When the silicone resin roller is in contact with the photoconductor, impurities of the silicone resin adhere to the photoconductor, causing contamination of the photoconductor and generation of vertical stripes. Further, a roller using a urethane resin easily adheres a low-melting-point material such as wax, which causes a reduction in the chargeability of the toner. The fixing aid of the toner is fused to the elastic blade, and vertical streaks are generated in the toner layer.

Therefore, the use of the fluorine-containing compound of the present embodiment can prevent the offset property in the fixing without using oil, and suppress the aggregation of the toner by adding the positively chargeable silica or the low-resistance metal oxide fine powder. No aggregation or fusion occurs. Further, since the fluorine-containing compound is uniformly dispersed in the toner, the charge is stabilized, the fog is less generated, and the image can be stabilized even after long-term use.

A primary transfer process for transferring the toner image formed on the surface of the image carrier to the surface of the endless intermediate transfer member by transferring the toner image to the surface of the intermediate carrier is brought into contact with the surface of the image carrier. Is executed several times repeatedly, after which
An electronic device including a transfer system configured to execute a secondary transfer process for collectively transferring an overlap transfer toner image formed on the surface of the intermediate transfer member to a transfer material by repeatedly executing the primary transfer process a plurality of times. It is suitably used for photographic devices. At this time, the photosensitive member and the intermediate transfer member are 9.8.
The toner on the photoreceptor is transferred by pressure contact at a pressure of × 10 ^{2 to} 2 × 10 ⁵ (N / m ² ). Further, the toner image formed on the surface of the intermediate transfer member is pressed onto the surface of the intermediate transfer member by a transfer member at a pressure of 5 × 10 ³ to 2 × 10 ⁵ (N / m ² ) via a recording sheet, and is pressed onto the recording material. The toner is transferred.

Thus, the use of the fluorine-containing compound of the present embodiment can prevent the offset property in the fixing without using oil, and suppresses the aggregation of the toner by adding the positively chargeable silica or the low-resistance metal oxide fine powder. It is possible to prevent overcharging, stabilize the charging property, prevent hollowing during transfer, and obtain high transfer efficiency. Further, the occurrence of filming on the intermediate transfer member and the photosensitive member can be prevented, and the transfer paper can be prevented from being contaminated by unnecessary toner particles. In addition, since filming of toner and free silica on the transfer roller surface can be prevented,
Image defects caused by retransfer of toner and free silica from the surface of the transfer roller to the surface of the photoreceptor can also be prevented. The characteristics can be more suitably stabilized with respect to the small particle size toner.

Further, a plurality of movable image forming units which are provided with a rotating photoreceptor and developing means having toners of different colors and form toner images of different colors on the photoreceptor are arranged in an annular shape. A color image formed by rotating and moving the entire image forming unit group, transferring the toner images of different colors formed on the photoreceptor onto the transfer material in a superposed manner and forming a color image It is suitably used for electrophotographic devices. Because the whole image forming unit rotates, it is cleaned from the photoconductor,
A situation in which the waste toner separated from the photoreceptor temporarily and repeatedly adheres to the photoreceptor always occurs. When the waste toner repeatedly contacts the photoconductor, filming on the image carrier is remarkably apt to occur, which causes a reduction in the life of the photoconductor.

In addition, since the toner moves violently up and down due to the rotation of the image forming unit, the toner tends to spill out of the seal portion. Therefore, it is necessary to further strengthen the seal at the seal portion, and the fusing phenomenon occurs. Occurs, and it becomes a lump, causing image noise of black and white streaks.

Further, a situation occurs in which the toner is always temporarily detached from the developing roller, and if the charge rising property is poor in the early stage of development, it causes ground fog. In the toner in which the unevenly distributed wax having the poor dispersion is present, the charge rising property tends to be deteriorated.

Therefore, the use of the fluorine-containing compound of the present embodiment can prevent the offset property in the fixing without using oil, and suppresses the aggregation of the toner by adding positively chargeable silica or low-resistance metal oxide fine powder. Overcharging can be prevented, charging stability can be obtained, charging can be started quickly, overcharging can be prevented at low temperature and low humidity, and background fogging in the early stage of development does not occur. Filming and fusion can be prevented, and long-term stable development characteristics can be obtained.

The toner is prepared through the steps of preliminary mixing, melt-kneading, pulverizing and classifying, and external addition.

The premixing treatment is a treatment in which the binder resin and the additives to be dispersed therein are uniformly dispersed by a mixer equipped with stirring blades or the like. As the mixer, a well-known mixer such as a super mixer (manufactured by Kawada Seisakusho), a Henschel mixer (manufactured by Mitsui Miike Kogyo), a PS mixer (manufactured by Shinko Pantech), a Reedige mixer or the like is used.

The hot melt kneading is performed by PCM30 (Ikegai), and the obtained toner mass is roughly pulverized by a cutter mill or the like, and then jet mill pulverized (for example, ID).
(S pulverizer, Nippon Pneumatic Industrial Co., Ltd.) and the like, and further, if necessary, fine particles are cut by an airflow classifier to obtain toner particles (toner base particles) having a desired particle size distribution. Pulverization and classification by a mechanical method are also possible. For example, a kryptron pulverizer (Kawasaki Heavy Industries) or a turbo mill (Kawasaki Heavy Industries) that pours toner into a small gap between a fixed stator and a rotating roller and pulverizes the toner. Turbo industry). By this classification process, toner particles (toner base particles) having a volume average particle diameter in the range of 3 to 6 μm are obtained.

The external addition treatment is a treatment in which an external additive such as silica is mixed with the toner particles (toner base particles) obtained by the classification. Known mixers such as a Henschel mixer and a super mixer are used for this.

Next, the present invention will be described in more detail with reference to examples.

Table 1 shows the properties of the binder resin used in the examples. As the resin, a polyester resin containing bisphenol A propyl oxide adduct, terephthalic acid, trimellitic acid, and succinic acid as main components was used, and a resin having different thermal characteristics depending on the blending ratio and polymerization conditions was used. AV indicates the acid value of the resin.

[0161]

[Table 1]

Mnf is the number average molecular weight of the binder resin, Mwf
Is the weight average molecular weight of the binder resin, Wmf is the ratio Mwf / Mnf of the weight average molecular weight Mwf to the number average molecular weight Mnf, W
zf is the Z average molecular weight Mzf and the number average molecular weight M of the binder resin.
The nf ratio Mzf / Mnf is shown.

Table 2 shows the characteristics of the hydrophobic silica used in the examples.

[0164]

[Table 2]

Table 3 shows the characteristics of the low-resistance metal oxide fine particles and metal salt-based fine powder used in the examples.

[0166]

[Table 3]

Table 4 shows the fluorine-containing compounds (fixing aids) used in the examples and their differential scanning calorimetry (DSC characteristics). The intersection of the tangent of the rising curve at the start of endotherm at the time of temperature rise and the tangent of the curve leading to the peak after rising is defined as the tangential melting point temperature.

[0168]

[Table 4]

Table 5 shows the toner material composition used in this example. The weight average particle size of each toner is 3 to 6
The prototype was manufactured such that the variation coefficient of the volume particle size distribution was 20 to 25% and the variation coefficient of the number particle size distribution was 25 to 30%.

[0170]

[Table 5]

For each pigment, black is carbon black (CB) and magenta pigment is C.I. I. Pigment Red 57: 1, and the yellow pigment is C.I. I. Pigment
Yellow 180 and cyan pigment are C.I. I. Pigment
Blue 15: 3 phthalocyanine was used. As the charge control agent, E84 (a zinc salicylate metal complex compound) manufactured by Orient Chemical Co., Ltd. is used, and the compounding amount ratio is shown in parentheses with respect to the compounding amount (parts by weight) relative to 100 parts by weight of the binder resin. silica,
The amounts of the low-resistance metal oxide fine particles and the metal salt-based fine powder indicate the amounts (parts by weight) based on 100 parts by weight of the toner matrix.

In the external addition process, the stirring blade
Z0S0 type, rotation speed 2000min ^-1, Processing time 5 minutes,
The test was performed with an input amount of 1 kg.

(Embodiment 1) FIG. 1 is a sectional view showing the structure of an electrophotographic apparatus used in this embodiment. The apparatus of this embodiment has a configuration in which a FP7750 (Matsushita Electric) copying machine is modified for reversal development and a waste toner recycling mechanism is added.

Reference numeral 301 denotes an organic photoreceptor. A charge generation layer is formed by depositing oxotitanium phthalocyanine powder on an aluminum conductive support, and a polycarbonate resin (Z-200 manufactured by Mitsubishi Gas Chemical) and butadiene are formed thereon. And a charge transport layer containing a mixture of hydrazone and hydrazone.

A roller 302 negatively charges the photosensitive member.
A charger 303 controls a charging potential of the photoconductor.
A reference electrode 304 is a signal light. 305 is a development three
306 is a doctor blade, 307 is a carrier holding
Roll 308, carrier 309
Is a toner. The carrier is methyl silicone resin,
Phenyl silicone resin, butyl acrylate 2: 6: 2
And coat it on the surface of Mn-Mg ferrite particles.
Was. The average particle size is 40-60 μm and the volume resistance is 10 ¹²Ωcm
It is. Use TB-1, 2, 3 listed in Table 5 for toner.
Used.

Reference numeral 310 denotes a voltage generator, reference numeral 311 denotes waste toner remaining after transfer, reference numeral 312 denotes a cleaning box, and reference numeral 313 denotes a transport pipe for returning the waste toner 311 in the cleaning box 312 to the developing step. The transfer residual toner is scraped off by the cleaning blade 314, and the waste toner 311 temporarily stored in the cleaning box 312 is removed.
Is configured to be returned to the developing step by the transport pipe 313.

Reference numeral 314 transfers the toner image on the photosensitive member to paper.
Transfer roller, the surface of which contacts the surface of photoreceptor 301
Is set to Transfer roller 314 is conductive
Elasticity provided with conductive elastic members around the shaft made of metal
Roller. The pressing force on the photosensitive member 301 is the transfer roller 3
14 per one (about 216 mm) 0 to 1.96 × 10 ^Five
N / m^Two, Preferably 4.9 × 10^Three~ 9.8 x 10^FourN
/ M^TwoIt is. This is to transfer the transfer roller 314 to the photosensitive member 301.
Measured from the product of the spring coefficient and the amount of shrinkage of the spring for pressing against
did.

The width of contact with the photosensitive member 301 is about 0.5 mm to
5 mm. The rubber hardness of the transfer roller 314 is 80 degrees or less, preferably 30 to 70 degrees, as measured by Asker C (measurement using a block piece instead of a roller shape).
If the angle is smaller than 30 degrees, the transfer efficiency decreases and the amount of waste toner increases. If it is greater than 70 degrees, omission during transfer tends to occur. Since the internal additive of the present configuration can be uniformly dispersed, the above range is necessary to sufficiently exhibit the effect.

The elastic roller 314 has a resistance value of 10 ⁷ Ω (an electrode is provided on the shaft and the surface, and 500 V is applied to both of them) by internally adding a lithium salt such as Li ₂₀ around a shaft having a diameter of 6 mm. The foamed urethane elastomer was used. The resistance is preferably in the range of 10 ⁵ to 10 ⁹ Ω. If it is smaller than 10 ⁵ , the transfer efficiency decreases and the amount of waste toner increases. If it is larger than 10 ⁹ , omission during transfer tends to occur. Since the internal additive of the present configuration can be uniformly dispersed, the above range is necessary to sufficiently exhibit the effect.

The overall outer diameter of the transfer roller 213 is 16.4 m.
m and hardness was 40 degrees for Asker C. The transfer roller 314 was brought into contact with the photosensitive member 301 by pressing the shaft of the transfer roller 314 with a metal spring. The pressing force is about 9.8 × 10
⁴ N / m ² . As the elastic body of the roller, besides the foamable urethane elastomer, CR rubber, NBR, S
Elastic bodies made of other materials such as i-rubber and fluorine rubber can also be used. As a conductivity-imparting agent for imparting conductivity, other conductive substances such as carbon black can be used in addition to the lithium salt.

Reference numeral 315 denotes a rush guide made of a conductive member for introducing the transfer paper to the transfer roller 314, and 316 denotes a transport guide in which the surface of the conductive member is insulated. The rush guide 315 and the transport guide 316 are grounded directly or via a resistor. 317 is transfer paper, 318 is transfer roller 3
14 is a voltage generating power supply for applying voltage to the power supply 14.

Table 6 shows the results of the image test.

[0183]

[Table 6]

In the image evaluation, the image density and the background fog were evaluated at the initial stage of image formation and after a durability test after 100,000 sheets have been printed. The ground fog was judged by visual observation, and it was judged as acceptable (（) if the level was practically acceptable.

After that, an image test of 1,000 sheets was performed while being left under high humidity, and an increase in fog was observed. The toner density control was poor, and the fog increased sharply when the toner was overtoned. Further, in another experiment, the image was allowed to stand overnight under high temperature and low humidity, and an image test was performed on 5,000 sheets the next day. The image density after 5,000 sheets is shown.

There was no horizontal line disturbance, toner scattering, transfer failure or paper back stain, and a solid black image was obtained without any missing characters and a high density image having an image density of 1.3 or more was obtained. . No ground fogging occurred in the non-image area. Further, when a long-term copy test of 100,000 sheets was performed, no filming was found on the surface of the photoreceptor, and a copied image of high density and low ground fog comparable to the initial image was obtained. No fogging occurred under high humidity, and no decrease in density occurred even under high temperature and low humidity.

Table 7 shows low-speed machines (process speed 140 mm
/ S) and a high-speed machine (450 mm /
The fixing rate of the fixing rate in s) was evaluated. In the storage stability test, the state of aggregation of the toner after standing at 50 ° C. for 24 hours was observed, and ○ indicates no aggregation and no practical problem, and X indicates a practically problematic level.

[0188]

[Table 7]

The process speed is related to the copy processing capacity of the machine per time, and indicates the peripheral speed of the photosensitive member. The conveying speed of the copy sheet is determined by the peripheral speed of the photoconductor.

Using copy paper of 80 g / m ² paper (Igepa), a fixing rate of 50 ± 50 patches of a patch having an image density of 1.0 ± 0.2 wound on each row in a row of Bencott (trademark, manufactured by Asahi Kasei Corporation).
The paper was rubbed 10 times with a 0 g (φ36 mm) weight, and the image density before and after the rubbing was measured by a Macbeth reflection densitometer, and defined by the rate of change.

The fixing rate is 80% or more, and the offset property is 18
A level of 0 ° C. or higher was regarded as a pass level.

The high-temperature offset property at low speed and the fixing rate at high speed showed good characteristics, and the high-speed machine and low-speed machine could be shared by one toner.

(Embodiment 2) FIG. 2 is a sectional view showing the structure of an electrophotographic apparatus for forming a full-color image used in this embodiment. In FIG. 2, reference numeral 1 denotes an outer casing of the color electrophotographic printer, and a right end face side in the drawing is a front face. Reference numeral 1A denotes a printer front plate. The front plate 1A can be freely opened and closed as shown by a dotted line with respect to the hinge shaft 1B on the lower side of the printer outer casing 1, and can be raised and closed as shown by a solid line. The operation of attaching and detaching the intermediate transfer belt unit 2 to and from the inside of the printer, and checking and maintaining the inside of the printer such as when a paper jam occurs, are performed by opening the front plate 1A to open the inside of the printer. The attachment / detachment operation of the intermediate transfer belt unit 2 is designed to be in a direction perpendicular to the rotation axis generatrix direction of the photoconductor.

FIG. 3 shows the structure of the intermediate transfer belt unit 2. The intermediate transfer belt unit 2 includes a unit housing 2a, an intermediate transfer belt 3, and a first conductive elastic body.
A transfer roller 4, a second transfer roller 5 made of an aluminum roller, a tension roller 6 for adjusting the tension of the intermediate transfer belt 3, a belt cleaner roller 7 for cleaning the toner image remaining on the intermediate transfer belt 3, and a cleaner roller 7 It includes a scraper 8 for scraping the collected toner, waste toner reservoirs 9a and 9b for storing the collected toner, and a position detector 10 for detecting the position of the intermediate transfer belt 3. As shown in FIG. 2, the intermediate transfer belt unit 2 can be detached from a predetermined storage portion in the printer outer casing 1 by opening the printer front plate 1A as shown by a dotted line and opening it.

The intermediate transfer belt 3 is used by kneading a conductive filler in an insulating resin and forming a film with an extruder. In this embodiment, a polycarbonate resin (for example, Iupilon Z300 manufactured by Mitsubishi Gas Chemical) is used as the insulating resin.
A film formed by adding 5 parts by weight of conductive carbon (for example, Ketjen black) to 95 parts by weight was used. The surface was coated with a fluorine resin. The thickness of the film is about 350 μm, and the resistance is about 10 ⁷ to 10 ⁹ Ω · cm. Here, the reason why the intermediate transfer belt 3 is formed by kneading a conductive filler into a polycarbonate resin and forming the film into a film can be used to effectively prevent the intermediate transfer belt 3 from being loosened due to long-term use and accumulation of electric charges. The reason why the surface is coated with the fluororesin is to effectively prevent toner filming on the surface of the intermediate transfer belt due to long-term use.

The intermediate transfer belt 3 is set to a thickness of 100 μm
The first transfer roller 4 formed of an endless belt-shaped film made of semiconductive urethane as a base material and formed around the periphery thereof with a low resistance treatment so as to have a resistance of 10 ⁶ to 10 ⁸ Ω · cm. Is wound around the second transfer roller 5 and the tension roller 6, and is configured to be movable in the direction of the arrow. Here, the peripheral length of the intermediate transfer belt 3 is equal to the longitudinal length (298 mm) of A4 paper, which is the maximum paper size.
The length is set to 360 mm, which is a sum of a length (62 mm) slightly longer than half the circumference of a photosensitive drum (diameter 30 mm) described later.

When the intermediate transfer belt unit 2 is mounted on the printer main body, the first transfer roller 4 is applied to the photosensitive member 11 (shown in FIG. 3) via the intermediate transfer belt 3 by about 9.8.
× 10 ⁴ (N / m ² ), and the second transfer roller 5 is connected to the third transfer roller 12 via the intermediate transfer belt 3 in the same manner as the first transfer roller 4 (see FIG. 3 (shown in FIG. 3). The third transfer roller 12 is configured to be rotatable following the intermediate transfer belt 3.

The cleaner roller 7 is a roller of a belt cleaner for cleaning the intermediate transfer belt 3. This is a configuration in which an AC voltage for electrostatically attracting toner is applied to a metallic roller. The cleaner roller 7 may be a rubber blade or a conductive fur brush to which a voltage is applied.

In FIG. 2, in the center of the printer, four fan-shaped image forming units 17Bk, 17Y, 17M, and 17C for each color of black, cyan, magenta, and yellow form an image forming unit group 18. Are arranged in an annular shape. Each image forming unit 17Bk, 17Y, 17M,
Reference numeral 17C denotes a printer top plate 1C which is opened about a hinge shaft 1D and is detachable at a predetermined position of the image forming unit group 18. Image forming units 17Bk, 17Y, 17M, 17
C is properly mounted in the printer, so that the mechanical drive system and the electric circuit system on both the image forming unit side and the printer side are connected via a mutual coupling member (not shown), and Electrically integrated.

Image forming unit 1 arranged in an annular shape
7Bk, 17C, 17M, 17Y is a support (not shown)
, Which is driven by a moving motor 19 as a whole, and is fixed and does not rotate.
It is configured to be rotatable around 0. Each image forming unit is rotated by an image forming position 2 facing a second transfer roller 4 that sequentially supports the intermediate transfer belt 3 described above.
1 can be located. The image forming position 21 is the signal light 2
2 is also the exposure position.

Each image forming unit 17Bk, 17C, 17
Since M and 17Y are made of the same components except for the developer put in, the image forming unit 17Bk for black will be described for simplification of description, and the description of the unit for other colors will be omitted.

Reference numeral 35 denotes a laser beam scanner disposed below the inside of the printer housing 1, and includes a semiconductor laser (not shown), a scanner motor 35a, a polygon mirror 35b,
It comprises a lens system 35c and the like. The pixel laser signal light 22 corresponding to the time-series electric pixel signal of the image information from the laser beam scanner unit 35 passes through an optical path window 36 formed between the image forming units 17Bk and 17Y, and passes through a part of the shaft 20. Incident on a fixed mirror 38 in the shaft 20 through a window 37 opened in the mirror, is reflected and enters the image forming unit 17Bk substantially horizontally from the exposure window 25 of the image forming unit 17Bk at the image forming position 21, The light passes through a passage between a developer reservoir 26 and a cleaner 34 which are disposed vertically in the image forming unit and is incident on an exposure portion on the left side surface of the photoconductor 11, and is scanned and exposed in the generatrix direction.

Here, since the optical path from the optical path window 36 to the mirror 38 uses the gap between the adjacent image forming units 17Bk and 17Y, the image forming unit group 1
8 has very little wasted space. Also, mirror 3
Since 8 is provided at the center of the image forming unit group 18, it can be constituted by a single fixed mirror, which is simple and easy to align.

Reference numeral 12 denotes a third transfer roller disposed inside the printer front plate 1A and above the paper feed roller 39. A nip portion where the intermediate transfer belt 3 and the third transfer roller 12 are pressed against each other is A paper transport path is formed so that paper is fed by a paper feed roller 39 provided below the printer front plate 1A.

A paper feed cassette 40 is provided on the lower side of the printer front plate 1A so as to protrude outward, and can set a plurality of papers S at the same time. 41a and 41b are paper transport timing rollers, 42a and 42b are fixing roller pairs provided on the upper inside of the printer, 43 is a paper guide plate provided between the third transfer roller 12 and the fixing roller pairs 42a and 42b, 44a
44b is a paper discharge roller pair disposed on the paper exit side of the fixing roller pairs 42a and 42b, and 47 is a cleaning roller of the fixing roller 42a.

The fixing device comprises a hollow roller made of aluminum or stainless steel having a heating means inside, a heating roller made of an elastic layer and a fluororesin tube, and a pressure roller. The outermost fluororesin tube has a thickness of 1 to 1
A tube selected from 00 μm, polytetrafluoroethylene, a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether, or a copolymer of tetrafluoroethylene and hexafluoroethylene is preferred. The elastic layer is preferably made of silicone rubber, fluorine rubber, fluorosilicone rubber, or ethylene propylene rubber. The elastic layer has a rubber hardness according to JIS standard of 10 to 70 degrees and a pressure roller of 4.9 × 10 ^{4 to} 1.96.
It is pressurized at a pressure of × 10 ⁶ N / m ² . In the present embodiment, a 50 μm thick polytetrafluoroethylene fluororesin tube and a rubber hardness of 70 degrees silicone rubber are used.
It is pressurized at a pressure of 1.47 × 10 ⁴ N / m ² . No fixing oil such as silicone oil is used.

Each image forming unit 17Bk, 17C, 17
M, 17Y, and the intermediate transfer belt unit 2 are provided with a waste toner reservoir.

Hereinafter, the operation will be described.

First, as shown in FIG. 2, the image forming unit group 18 moves the black image forming unit 17Bk to the image forming position 2B.
In one. At this time, the photoconductor 11 is in opposing contact with the first transfer roller 4 via the intermediate transfer belt 3.

In the image forming step, the black signal light is input to the image forming unit 17Bk by the laser beam scanner unit 35, and the image is formed by the black toner. At this time, the image forming speed of the image forming unit 17Bk (60 mm / s equal to the peripheral speed of the photoconductor) and the moving speed of the intermediate transfer belt 3 are set to be the same.
By the action of the transfer roller 4, the black toner image is transferred to the intermediate transfer belt 3.
Is transferred to At this time, a DC voltage of +1 kV was applied to the first transfer roller. Immediately after all the black toner images have been transferred, the image forming units 17Bk, 17C, 17C
M and 17Y as a whole are driven by a moving motor 19 as an image forming unit group 18 to rotate and move in the direction of the arrow in the drawing, and rotate exactly 90 degrees to stop at a position where the image forming unit 17C reaches the image forming position 21. . During this time, since the portions of the toner hopper 26 and the cleaner 34 other than the photoconductor of the image forming unit are located inside the rotation arc at the tip of the photoconductor 11, the intermediate transfer belt 3 does not contact the image forming unit.

After the image forming unit 17C arrives at the image forming position 21, the laser beam scanner unit 35 inputs the signal light 22 to the image forming unit 17C with a cyan signal as before, and forms a cyan toner image. Transfer is performed. By this time, the intermediate transfer belt 3 has made one rotation, and the writing timing of the cyan signal light is controlled such that the next cyan toner image is positionally matched with the previously transferred black toner image. During this time, the third transfer roller 12 and the cleaner roller 7 are slightly separated from the intermediate transfer belt 3 so as not to disturb the toner image on the transfer belt.

The same operation as described above was performed for magenta and yellow, and a color image was formed by superimposing the four color toner images on the intermediate transfer belt 3 in position. After the transfer of the final yellow toner image, the toner images of the four colors are collectively transferred to the sheet fed from the sheet cassette 40 by the action of the third transfer roller 12 in a timely manner. At this time, the second transfer roller 5 is grounded, and the third transfer roller 12
, A DC voltage of +1.5 kV was applied. The toner image transferred to the paper was fixed by the pair of fixing rollers 42a and 42b. The sheet was then discharged out of the apparatus via a pair of discharge rollers 44a and 44b. The transfer residual toner remaining on the intermediate transfer belt 3 is cleaned by the action of the cleaner roller 7 to prepare for the next image formation.

Next, the operation in the monochrome mode will be described. In the monochrome mode, first, the image forming unit of a predetermined color moves to the image forming position 21. Next, image formation of a predetermined color and transfer to the intermediate transfer belt 3 are performed in the same manner as before, and the transfer is continued as it is after the transfer, to the next sheet transferred from the sheet cassette 40 by the third transfer roller 12. The image was transferred and fixed.

In this apparatus, an image forming unit having a structure using a conventional developing method can be used as the structure of the image forming unit.

[0215] Table 8 shows the results of image formation using the electrophotographic apparatus of FIG.

[0216]

[Table 8]

When an image was formed using the toner manufactured as described above by using such an electrophotographic apparatus, the solid black image was uniform without any disturbance of horizontal lines, scattering of toner, and missing characters, and 16 images were obtained. An extremely high-resolution and high-quality image reproducing an image line of / mm was obtained, and a high-density image having an image density of 1.3 or more was obtained. No fogging of the non-image area occurred. Further, even in a long-term durability test of 10,000 sheets, both fluidity and image density showed little change and stable characteristics. Also, in the transfer, the hollow portion was at a practically acceptable level, and the transfer efficiency was 90%. Further, the filming of the toner on the photoreceptor and the intermediate transfer belt was at a practically acceptable level. But TM-5, T
For the toners of Y-5 and TB-4, filming of the photoreceptor and omission during transfer occurred, and much fog occurred.

Next, (Table 9) shows the amount of 0.4 g adhered to OHP paper.
/ Cm ² or more was fixed at 170 ° C. by a fixing device not coated with oil at 170 ° C., and the transmittance at high temperature was evaluated. Process speed is 100mm / s
The transmittance is spectrophotometer U-3200 (Hitachi, Ltd.)
Then, the transmittance of 700 nm light was measured. The results of fixability, offset resistance and storage stability are shown.

[0219]

[Table 9]

OHP translucency is 80% or more,
In addition, the non-offset temperature range was 40 to 60K, and a good fixing property was exhibited in a fixing roller using no oil. Aggregation was hardly observed at storage stability at 50 ° C. for 24 hours. However, the toners of TM-5 and TY-5 hardened in the storage stability test, and the non-offset temperature range was narrow.

[0221]

As described above, according to the present invention, by using a specific fluorine-containing polymer as a fixing aid, it is possible to achieve both high translucency and anti-offset properties, and to use an oil-free oil. It is possible to realize the fixing without the need.

Further, positively charged hydrophobic silica which is oppositely charged to the toner base is externally added. In addition, by using negatively chargeable silica, low-resistance metal oxide fine powder, and metal salt-based fine particles mixed with hydrophobic silica, toner aggregation seen in toners containing fluorine-containing polymers and long-term continuous use It can prevent image density decrease due to overcharging and fogging under low temperature and low humidity, improve dispersibility of fixing aid, have uniform charge distribution, and output stable image characteristics even after long-term use It is possible to continue.

Further, even when the toner is used in a contact type one-component developing method, thermal fusion or aggregation of the toner does not occur, and stable developability can be maintained.

In addition, by using an electrophotographic method using a conductive elastic roller or an intermediate transfer member, it is possible to prevent a dropout or scattering at the time of transfer and obtain a high transfer efficiency.

Further, even in long-term use under high humidity, filming of the photosensitive member and the intermediate transfer member can be prevented.

Also, even if the waste toner is recycled, the charge amount and the fluidity of the developer do not decrease, the coagulation does not occur, the life is extended, the recycling development is enabled, the prevention of global environmental pollution and the resource Can be reused.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of an electrophotographic apparatus used in an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a configuration of an electrophotographic apparatus used in an embodiment of the present invention.

FIG. 3 is a sectional view showing a configuration of an intermediate transfer belt unit used in the embodiment of the present invention.

FIG. 4 is a cross-sectional view illustrating a configuration of a developing unit used in an embodiment of the present invention.

[Explanation of symbols]

 2 Intermediate Transfer Belt Unit 3 Intermediate Transfer Belt 4 First Transfer Roller 5 Second Transfer Roller 6 Tension Roller 11 Photoconductor 12 Third Transfer Roller 17Bk, 17C, 17M, 17Y Image Forming Unit 18 Image Forming Unit Group 21 Image Forming Position 22 Laser signal light 35 Laser beam scanner unit 38 Mirror 308 Carrier 305 Developing sleeve 306 Doctor blade 307 Magnet roll 314 Cleaning blade 312 Cleaning box 311 Waste toner 313 Waste toner transport pipe

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 9/097 G03G 9/08 331 15/08 507 346 15/08 507L F-term (Reference) 2H005 AA01 AA06 AA08 CA02 CA08 CA11 CA12 CA14 CA20 CA25 CB07 CB08 CB13 DA02 DA03 DA06 EA01 EA05 EA07 EA10 2H077 AA37 AC04 AC16 AD06 AD13 AD31 AE03 EA14 EA15 FA22 GA01

Claims (21)

[Claims] 1. An external additive comprising at least a positively chargeable hydrophobic silica is added to a toner matrix comprising at least a fluorine-containing polymer, a polyester resin having an acid value of 10 or more, and a colorant. Toner. 2. A toner matrix comprising at least a fluorine-containing polymer, a polyester resin having an acid value of 10 or more, and a coloring agent is provided with at least a positively charged hydrophobic silica and a negatively charged hydrophobic silica. A toner to which an additive is added. 3. An external addition comprising at least a positively chargeable hydrophobic silica and a low-resistance metal oxide fine powder to a toner base comprising a polymer containing at least fluorine, a polyester resin having an acid value of 10 or more, and a colorant. A toner to which an agent is added. 4. A toner matrix comprising at least a fluorine-containing polymer, a polyester resin having an acid value of 10 or more, and a colorant, at least a hydrophobic silica having a positive chargeability, an average particle size of 0.02 to 4 μm, and nitrogen adsorption. A toner having a BET specific surface area of 0.1 to 100 m ² / g according to the present invention, comprising an external additive comprising a fine powder of titanate or a fine powder of zirconia acid. 5. A toner matrix comprising a charge control agent comprising a metal complex of a salicylic acid metal complex and / or a metal complex of a benzylic acid derivative.
The amount of 0.5 to 4 parts by weight per 00 parts by weight.
4. The toner according to item 4. 6. Oxidation in which the low-resistance metal oxide fine powder has an average particle size of 0.02 to ² μm, a BET specific surface area of 0.1 to 100 m ² / g by nitrogen adsorption, and an electric resistivity of 10 ⁹ Ωcm or less. A metal oxide fine powder comprising at least one of titanium fine powder, aluminum oxide fine powder, strontium oxide fine powder, tin oxide fine powder, zirconia fine powder, magnesium oxide fine powder, and indium oxide fine powder. Item 4. The toner according to Item 3. 7. The low-resistance metal oxide fine powder has an average particle size of 0.02 to 2 μm and a BET specific surface area of 1 to 2 by nitrogen adsorption.
4. The toner according to claim 3, comprising a fine powder of titanium oxide and / or silica oxide surface-treated with a mixture of 200 m ² / g of tin oxide-antimony. 8. The method of claim 1, wherein the hydrophobic silica is dimethyl silicone
Yl, methylphenyl silicone oil, alkyl modified
Silicone oil, fluorine-modified silicone oil,
-Modified silicone oil, epoxy-modified silicone oil
Nitrogen treated with at least one of
BET specific surface area is 30 ~ 350m ^Two/ G
5. The toner according to any one of claims 1 to 4. 9. The toner according to claim 4, wherein the titanate-based fine powder or the zirconiaate-based fine powder is prepared by a hydrothermal method or an oxalate pyrolysis method. 10. A fluorine-containing polymer having a specific gravity at 25 ° C. of not less than 1.05 and a tangent melting point temperature at the time of temperature rise in differential scanning calorimetry (a tangent to a rising curve at the start of endothermic time at the time of temperature rise; The point of intersection with the tangent of the curve leading to the peak after rising is the tangent melting point temperature) of 70 to 140
The toner according to any one of claims 1 to 4, wherein the toner has a peak temperature of 73C to 148C, and a difference between the peak temperature and the tangential melting point temperature is 20K or less. 11. The toner according to claim 1, wherein the fluorine-containing polymer has an average particle size of 1 to 11 μm. 12. Assuming that the average particle size of the fluorine-containing polymer is FP and the average particle size of the toner is TP, 0.3 <FP /
The toner according to claim 1, wherein TP <0.9. 13. The method according to claim 1, wherein the fluorine-containing polymer is a copolymer of olefin and tetrafluoroethylene.
5. The toner according to any one of items 1 to 4, above. 14. The toner according to claim 1, wherein the fluorine-containing polymer is jojoba oil or meadowfoam oil to which partial fluorine or extremely fluorine has been added. 15. The method according to claim 1, wherein the fluorine-containing polymer is a copolymer of tetrafluoroethylene and an acrylate represented by the formula (1) and / or the formula (2). toner. Embedded image Embedded image 16. The fluorine-containing polymer is a copolymer of tetrafluoroethylene, an olefin and an acrylate represented by the formula (1) and / or the formula (2). The toner according to any one of the above. 17. A waste toner recycling means for recovering toner remaining on an image carrier after a transfer process into a developing device and reusing the toner in the developing process.
An electrophotographic apparatus, wherein the toner according to claim 6 is used. 18. An electrostatic latent image on the image carrier is made visible by inserting a transfer material between the image holding member and the conductive elastic roller and applying a transfer bias voltage to the conductive elastic roller. 17. An electrophotographic apparatus comprising a toner transfer unit for transferring an imaged toner, wherein the toner according to claim 1 is used. 19. A developing roller made of a silicone resin or a urethane resin rotatably supported by a shaft and in contact with a photoreceptor, and the toner is developed by a supply roller made of a urethane resin rotatably supported and in contact with the developing roller. 2. A non-magnetic one-component means for supplying to a roller, forming a toner layer by contacting a doctor blade on the developing roll, and contacting the developing roller with a photoreceptor for development. An electrophotographic apparatus using the toner described in any one of (1) to (16). 20. A surface of the intermediate transfer member, wherein the toner image obtained by visualizing the electrostatic latent image formed on the image carrier is brought into contact with the surface of the endless intermediate transfer member against the image carrier. The primary transfer process for transferring the toner image to the intermediate transfer member is repeatedly performed a plurality of times. An electrophotographic apparatus comprising a transfer system configured to execute a secondary transfer process for transferring, and using the toner according to any one of claims 1 to 16. 21. A plurality of movable image forming units each including at least a rotating image carrier and developing means having toners of different colors, wherein toner images of different colors are formed on the image carrier. An image forming unit, an image forming position composed of a single exposure position and a single transfer position,
An image forming unit group in which the plurality of image forming units are arranged in an annular shape, and each of the plurality of image forming units,
A moving unit for rotating the entire image forming unit group to sequentially move to the single image forming position, an exposure unit for generating signal light, and the rotation center of the image forming unit group substantially at the center of rotation. 17. The toner according to claim 1, further comprising: a color image forming system having a mirror for guiding light from an exposure unit to the exposure position, and transferring a toner image of a different color onto a transfer material in a superposed manner. An electrophotographic apparatus characterized by using: