JPH09244292A - Toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To embody the miniaturization and simplification of a device, the adaptation to a development method which allows a cost reduction and high image quality of high densities an low ground fogging by incorporating specific wax composed of at least polyethylene(PE) into a binder resin. SOLUTION: The wax composed of at least the PE is incorporated into the binder resin of the toners at 5 to 10 pts.wt. per 100 pts.wt. binder resin. The wax is formed by a thermal decomposition method. The recover rate in the case of washing for one hour with toluene at 25 deg. is >=95% and the softening point of the wax is 80 to 140 deg.. The needle penetration rate at 25 deg.C is <=8. The toners are 0.3<=(St-Sb)/(Sa*<m> W / 100)<=0.7 when the specific surface area of the toners is defined as St(m<2> /g), the specific surface area of the toner base material as Sb(m<2> /g), the specific surface area of external additives as Sa(m<2> /g) and the addition amt. of the external additives as W(wt.%). A release agent, a flow property assistant, such as powder of org. materials, electrostatic charge assistant and cleaning assistant may be incorporated at need into the toners.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to toner used in copying machines, printers and facsimiles.

[0002]

2. Description of the Related Art In an electrophotographic copying machine or printer, printing is performed by the following process. First, a photoreceptor (hereinafter referred to as a photoreceptor) is charged for forming an image. As a charging method, a conventionally used corona charger is used, and in recent years, a contact type charging method in which a conductive roller is directly pressed against the photoreceptor to reduce the amount of ozone generation is used. A means for uniformly charging the surface has been put into practical use. After charging the photoconductor, in the case of a copying machine, the copy original is irradiated with light and reflected light is applied to the photoconductor through a lens system. Further, 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 the light on and off. When a latent image (high or low surface potential) is formed on the photoconductor, the photoconductor is visualized with toner (having a diameter of about 5 μm to 15 μm) which is precharged colored powder. The toner adheres to the surface of the photoconductor according to the level of the surface potential of the photoconductor, and is then electrically transferred to the copy paper. That is, the toner is charged positively or negatively in advance, and a charge having a polarity opposite to the polarity of the toner is applied from the back surface of the copy sheet and is electrically attracted. Heretofore, a corona discharger has been widely used as the charge applying method, similarly to the charging method. However, in recent years, a transfer device using a conductive roller has been put to practical use in order to reduce the amount of ozone generated. At the time of transfer, not all the toner on the photoconductor is transferred to the copy sheet, but a part of the toner remains on the photoconductor. This residual toner is scraped off by a cleaning blade or the like in the cleaning section to become waste toner. Conventionally, in the electrophotographic method, the waste toner has been discarded without being reused. In terms of environmental protection, careless disposal should be avoided, and reuse of waste toner is an important issue.

Conventionally, a cascade developing method, a touch-down developing method, a jumping developing method and the like are known as developing methods for making an electrostatic latent image visible by an electrophotographic method. Among them, cascade development disclosed in U.S. Pat. No. 3,105,770 is known as a development method in which a developer is directly sprayed on a photoconductor. The cascade developing method is a developing method used for the first practical copying machine of the electrophotographic method. U.S. Pat. No. 3,866,574 discloses a method in which an AC bias is applied to a developing roller to cause one-component toner to fly and develop. According to the present invention, it is described that the AC bias applied to the developing roller is used for activating the movement of the toner, and the toner flies to the image portion, and returns to the middle in the non-image portion.

Further, as an improved technique for applying the AC bias, there is a jumping development disclosed in Japanese Patent Publication No. 63-42256. In this jumping development method, toner is carried on a toner carrier, and a rigid or elastic regulating blade is provided on the toner carrier with a small gap from the carrier. Then, the toner is regulated to a thin layer by the regulating blade and transported to the developing section, where the toner is attached to the image area of the photoconductor by an AC bias. The technical idea of Japanese Patent Publication No. 63-42256 differs from the above-mentioned US Pat. No. 3,866,574 in that the toner reciprocates in the image portion and the non-image portion.

FIG. 4 shows Japanese Patent Laid-Open No. 48-69524, US Pat. No. 2,807,233, and Japanese Patent Laid-Open No. 3-1555.
FIG. 90 is a schematic diagram showing a configuration of a toner image transfer device disclosed in Japanese Patent Publication No. 84, etc.

In FIG. 4, 100 is a transfer roller made of foamed or solid rubber and adjusted to a medium resistance of about 10 ⁷ Ω, 101 is a power source for applying voltage to the transfer roller, and 102 is a photoconductor. Reference numeral 103 is a transfer paper, and 104 is a toner. The operation of the transfer device configured as described above will be described.

The above-mentioned toner image is formed on the surface of the photoconductor 102. Since the transfer roller 100 is in contact with the photoconductor 102 with a predetermined pressing force, the transfer paper 103 is pressed against the photoconductor 102 and comes into contact with the toner 104. Since a voltage having a polarity opposite to that of the toner 104 is applied to the transfer roller 100 from the power supply device 101, the toner 104 is transferred to the transfer paper 103. Power supply device 101 for contact transfer
The applied voltage is as low as several hundred to 3000 V, and the harmful ozone generation amount can be suppressed to a very low level as compared with the conventional corona transfer device.

Further, in a color copying machine, a photoconductor is charged by corona discharge by a charging charger, and then a latent image of each color is applied as a light signal to the photoconductor to form an electrostatic latent image, and a first color, for example, is formed. Develop with yellow toner to visualize the latent image.

After that, the transfer medium is brought into contact with the photoconductor, which is charged with a polarity opposite to that of the yellow toner, and the yellow toner image formed on the photoconductor is transferred. The photoconductor is destaticized after cleaning the toner remaining at the time of transfer, and finishes development and transfer of the first color toner.

After that, the same operation as that for the yellow toner is repeated for magenta and cyan toners, and the toner images of the respective colors are superposed on the transfer material to form a color image. Then, these superposed toner images are transferred to a transfer paper charged with a polarity opposite to that of the toner, and then fixed and copying is completed.

As the color image forming method, toner images of respective colors are sequentially formed on a single photoconductor, and the transfer material wound around a transfer drum is rotated to repeatedly face the photoconductor, and sequentially formed there. A transfer drum method in which toner images of respective colors are transferred in an overlapping manner, and a plurality of image forming units are arranged side by side, and the toner images of respective colors are sequentially passed through a transfer material conveyed by a belt through the respective image forming units. A continuous superposition method of transferring and superimposing color images is common.

A color image forming apparatus using the above-mentioned transfer drum system is disclosed in Japanese Patent Laid-Open No. 1-252982. FIG. 7 shows an outline of the entire configuration of the conventional example, and the configuration and operation will be briefly described below.

In FIG. 7, reference numeral 501 denotes a photoconductor, which is provided with a charger 502, a developing unit 503, a transfer drum 504, and a cleaner 505 facing the photoconductor. Development unit 50
3 is a Y developing device 50 for forming a yellow toner image
6, a magenta M developing device 507, a cyan C developing device 508, and a black Bk developing device 509. The entire developing device group rotates so that each developing device sequentially faces the photoconductor 501 and develops. It becomes possible. During operation, the transfer drum 512 and the photoconductor are opposed to each other and rotate in the direction of the arrow at a constant speed.

When the image forming operation starts, the photoconductor 501 rotates in the direction of the arrow, and the surface of the photoconductor 501 is uniformly charged by the charger 502. Thereafter, the surface of the photoconductor is irradiated with a laser beam 510 modulated with a signal for forming a yellow image of the first color to form a latent image. Next, this latent image is first transferred to the Y developing device 506 facing the photoconductor.
Is developed, and a yellow toner image is formed. The yellow toner image formed on the photoconductor is transferred onto the transfer drum 504.
By the time it moves to the position facing the
On the outer periphery of 04, a sheet of paper as a transfer material sent from the paper feeding section 511 is wrapped around with its front end grasped by the claw section 512, and the yellow toner image on the photoconductor is placed at a predetermined position on the sheet. Are timed so that they will meet face to face.

After the yellow toner image on the photoconductor is transferred onto the sheet by the action of the transfer charger 513, the surface of the photoconductor is cleaned by the cleaner 505 to prepare the image formation of the next color. Subsequently, magenta, cyan, and black toner images are also formed in the same manner, but at that time, the developing unit 503 makes each developing device used according to the color face the photoconductor to be in a developable state. The diameter of the transfer drum is large enough so that the longest sheet of paper can be wound and the developing unit can be exchanged between images of each color.

Laser beam 510 for image formation of each color
The irradiation is performed with a timing such that the toner images of the respective colors on the photoconductor and the toner images already transferred to the sheet on the transfer drum are aligned and face each other as the toner rotates. In this way, the four color toner images are transferred to the transfer drum 50.
4 is transferred onto the paper in a superimposed manner to form a color image on the paper. After the toner images of all colors have been transferred, the paper is peeled from the transfer drum 504 by the peeling claw 514, the toner image is fixed by the fixing device 516 via the conveyance unit 515, and the paper is ejected to the outside of the apparatus.

On the other hand, as an example of a color image forming apparatus using a continuous transfer system, there is JP-A-1-250970. In this conventional example, four image forming stations each including a photoconductor, an optical scanning unit, and the like are arranged to form an image of four colors, and a sheet conveyed on a belt passes under the respective photoconductors to form a color image. The toner images are overlaid.

Further, as another method of forming a color image by superimposing toner images of different colors on a transfer material, toner images of respective colors sequentially formed on the photosensitive member are once superposed on the intermediate transfer material, and finally. Japanese Patent Application Laid-Open No. 2-212867 discloses a method of collectively transferring the toner images on the intermediate transfer material onto a transfer paper.

As a fixing method used for permanently fixing the toner transferred to the copy paper on the paper, a heat roll method, a pressure roll method, a flash fixing method, a method using a chemical agent, etc. are known. Among them, a thermal roll method in which a toner is melted in a contact state and fixed on paper is generally used in terms of energy efficiency, safety, and print quality.

As is well known, the toner for electrostatic charge development used in these developing methods generally requires a binder resin component, a coloring component composed of a pigment or a dye, a plasticizer and a charge control agent, and further requires a further component. According to the above, it is composed of an additive component such as a magnetic material and a release agent and an external additive. As the binder resin component, a natural or synthetic resin may be used alone or may be used in a suitable mixture.

Then, the binder resin component and the additive component are premixed in appropriate proportions, thermally kneaded by hot melting, finely pulverized, and if necessary classified, and an external additive is externally added to the toner. Is obtained.

[0022]

However, in the above configuration,
While the printing is repeated, the toner may adhere to the surface of the photoconductor, the surface of the carrier, or the surface of the toner carrier, so-called toner filming phenomenon may occur. This is considered to occur because the toner binder resin, wax, and the like have a cohesive property and are difficult to remove when softened, and the toner adheres to the part. When toner adheres to the surface of the photoconductor, light is blocked during exposure according to the image pattern, an electrostatic latent image is not formed, black spots occur in forward development, and white spots occur in reverse development, resulting in image defects. Becomes

When the toner adheres to the surface of the carrier, the amount of charge required for the toner is not given from the carrier, the amount of charge is reduced, and the image quality is significantly deteriorated.

When the toner adheres to the surface of the toner carrier,
The toner is not conveyed only to that portion, and printing failure occurs.

In recent years, from the viewpoint of cost and productivity, attempts have been made to adapt one kind of toner from a low speed machine to a high speed machine, but this toner filming phenomenon becomes remarkable as the printing speed increases. That is, since the fixing speed also needs to be increased in response to the increase in the printing speed, the amount of heat given to the toner per unit time is reduced. Therefore, the viscosity of the binder resin of the toner is reduced so that the toner can be fixed with a small amount of heat. This is because the low molecular weight component that contributes to the fixing property by penetrating into the copy paper increases due to the low viscosity. However, the lowering of the viscosity lowers the strength of the binder resin itself and increases the cohesiveness, so that the sticking becomes severe. When this toner is applied to a low-speed machine with a low fixing speed, the viscoelasticity of the binder resin is insufficient, so the toner on the copy paper adheres to the fixing roller during fixing, and the toner on the copy paper rotates as the roller rotates. A so-called hot offset phenomenon occurs in which retransfer occurs.

Further, since the same amount of heat is applied during fixing, it is not preferable to raise the fixing temperature from the viewpoints of increased power consumption, increased temperature inside the apparatus, and increased warm-up time.

With the molecular weight distribution of the binder resin as two peaks,
A method of functionally separating each of the high molecular weight region and the low molecular weight region is used. In other words, the high molecular weight region is provided with hot offset resistance by utilizing the resin strength, and the low molecular weight region is provided with the fixing property to the copy paper. However, this method can deal with a narrow fixing speed range, but has a narrow tolerance to a wide range of requirements from low speed machines to high speed machines, and cannot achieve both fixability, hot offset resistance and filming resistance. .

It is common practice to add a low molecular weight polypropylene wax or polyethylene wax to improve the fixability. Polypropylene wax is effective in improving the hot offset phenomenon because of its releasing effect, but has little effect in improving fixability in high-speed fixing. Since polyethylene wax has a friction reducing effect by itself, even if low molecular weight components that contribute to fixability by infiltrating into copy paper have the same amount, they are effective in improving fixability. That is, the fixing effect of the polyethylene wax is not due to the strengthening of the bond between the copying paper and the toner, but due to the effect of releasing the external force.

However, since both waxes are present in large amounts in the vicinity of the surface in the toner base, the toner filming phenomenon is promoted and the toner storability is deteriorated. This phenomenon is remarkable in a wax prepared by a low-pressure polymerization method containing a large amount of low-boiling components. The low boiling point component can be removed by toluene, but it is not practical because it has a drying step after the removal. Conversely, it can be said that a wax having a high recovery rate by washing with toluene has little low-boiling components.

Since the wax is unevenly distributed in the toner, the compatibility between the wax component and the binder resin component constituting the toner base is poor. Therefore, at the interface between the wax and the binder resin in the pulverizing step during toner preparation. This is due to the fact that crushing is easy.

Since the wax is softer than the binder resin, the fluidity of the toner is deteriorated. It is considered that this is because the wax portion is plastically deformed when the toner flows.

For this reason, an external additive is added as a toner fluidizing agent, but if it is simply added, the external additive itself is released from the toner base and adheres to the photoreceptor to cause scratches, which triggers filming. Will end up. Further, under the condition that a large number of such liberated external additives are present, the toner fluidity is not stable, which leads to deterioration of image quality and deterioration of waste toner recyclability.

It is well known in this technical field regarding the developing method, but the cascade developing method has a problem that it is not good at reproducing a solid image and the apparatus becomes large and complicated. It was In addition, US Pat.
The 6574 developing device has a problem that high precision is required for the apparatus, and it is complicated and high cost. In the jumping development method, it was essential to form an extremely uniform thin layer on a toner carrier carrying a toner layer. Further, in this method, the history of the previous image often remains in the thin toner layer on the toner carrier, and so-called sleeve ghost development occurs in which an afterimage appears in the image. Further, there is a disadvantage that the apparatus is complicated and the cost is high.

Therefore, the applicant of the present invention has proposed a new electrophotographic method capable of realizing downsizing and high performance of development (Japanese Patent Laid-Open No. 5-72).
No. 890). In the electrophotographic development method, a non-image portion is not required by a photoreceptor including a fixed magnet and a toner collecting electrode roller (hereinafter, referred to as an electrode roller) having a magnet opposed to the photoreceptor with a predetermined gap. This is a configuration for removing toner. This developing method is a method that faithfully reproduces a solid image, does not generate a sleeve ghost, and enables further downsizing, simplification, and cost reduction of the apparatus.

However, in order to improve the image quality and stabilize the image quality for a long time by using this developing method, higher performance toner characteristics are required.

This is because the developing method does not use a regulating blade for regulating the toner in a thin layer, and therefore the toner is not regulated in the layer and is conveyed to the developing field which is a narrow gap space between the photoconductor and the electrode roller. To be done. Therefore, there is little space and space for the toner to obtain a desired amount of charge by frictional charging, and therefore, the toner needs a more uniform and higher charging characteristic than before. The phenomenon that unevenness occurs in the solid black image portion and the halftone image portion and that the background fog increases in the non-image portion are noticeable in the toner having poor fluidity. This is because the triboelectric chargeability varies among the toners, and uniform toner chargeability cannot be obtained.

Further, since the toner used in this developing method contains a magnetic material, the binder resin component that contributes to the fixing is necessarily small. For this reason, the toner is required to have higher fixing performance than before.

Further, in the electrophotographic method using the toner according to the present invention, since the toner is first sprinkled on the entire photoconductor in the developing step, the toner and the photoconductor are in contact with each other for a longer time than in the conventional developing method. Therefore, the toner filming is more likely to occur.

Further, the electrophotographic method using the toner according to the present invention has a structure in which the waste toner removed in the cleaning step is returned to the developing step and reused for recycling.

The waste toner removed in the cleaning step and returned to the developing step has a characteristic largely different from that of the initial toner and adversely affects the image. This is due to the fact that the toner is stressed in the cleaning unit and the fluidity is reduced.

Further, the electrophotographic method using the toner according to the present invention has a constitution in which a conductive elastic roller is used in the transfer step. In the transfer method using the conductive elastic roller,
There is a problem such as stain on the back side of the paper caused by the contamination of the transfer roller with the toner.

When the toner on the photoconductor is transferred onto the transfer paper by using the transfer roller, the transfer roller is in contact with the photoconductor at a predetermined pressure in the absence of the paper. For this reason, if there is much fog in the developing process, the transfer roller is contaminated, and the back surface of the paper is stained.

Further, since the roller transfer is a contact transfer, it is sensitive to the surface condition of the photosensitive member, and unevenness occurs in the image even when filming is not a problem in the conventional corona transfer.

Further, the electrophotographic method using the toner according to the present invention uses the intermediate transfer member.

In the transfer drum system, a transfer drum is used to align and superimpose toner images of different colors. The transfer drum is rotated at the same speed with respect to the photoconductor, and the timing of the leading edge of the image is adjusted to match the mutual positions of the toner images of the respective colors when a color image is formed. However, in the above configuration, since it is necessary to wind the paper around the transfer drum, the diameter of the transfer drum needs to be a certain size or more, and the structure is very complicated and high accuracy is required. Was large and expensive. Also, strong paper such as postcards and thick paper could not be used because it could not be wound around the transfer drum.

On the other hand, the continuous transfer method has an image forming position corresponding to the number of colors, and it suffices to pass the sheets of paper one after another, so such a transfer drum is unnecessary, but this method is used. In this case, a plurality of latent image forming means such as a laser optical system for forming a latent image on the photoconductor are required corresponding to the number of colors, and the structure is very complicated and expensive. Furthermore,
Since there are multiple image forming positions, relative misalignment of the image forming parts for each color, eccentricity of the rotation axis, deviation of the parallelism of each part, etc. directly affect the color misregistration, and it is difficult to stably obtain high image quality. there were. In particular, it is necessary to accurately align the positions of the latent images by the latent image forming means.
As disclosed in the publication, there is a problem that the image exposure system, which is a latent image forming means, requires considerable devise and a complicated structure.

Further, Japanese Patent Laid-Open No. 2-2 using an intermediate transfer material
In the example of 12867, a plurality of developing devices must be arranged around a single photoconductor in order to form toner images of respective colors on the same photoconductor, and the shape of the photoconductor is inevitable. Became large, and the photoreceptor became a belt shape that was difficult to handle. Also, if each developing device is replaced during maintenance, matching adjustment with the characteristics of the photoconductor is necessary,
Since it was necessary to adjust the position between the photoconductors and the developing devices when the photoconductors were replaced, it was difficult to maintain the color developing devices and the photoconductors.

However, the intermediate transfer system does not require a complicated optical system, and can be used for strong paper such as postcards and thick paper. Also, since the intermediate transfer belt is flexible, the transfer drum system and the continuous transfer system can be used. Compared with the method, there is an advantage that the device itself can be downsized.

However, although it is ideal that the toner is completely transferred at the time of transfer, some transfer residue remains. The so-called transfer efficiency is not 100%, but is generally about 75 to 90%. The toner remaining after the transfer is scraped off by a cleaning blade or the like in the step of cleaning the photoconductor to become waste toner.

In the structure using the intermediate transfer member, the toner is transferred from the photosensitive member to the intermediate transfer member and further from the intermediate transfer member to the image receiving paper at least twice or more. In the copying machine of, for example, even if the transfer efficiency is 85%, the transfer efficiency is 72% by performing the transfer twice.
Fall to. Furthermore, if the transfer efficiency is 75% in one transfer, about 56% of the toner becomes waste toner, which means that the cost of the toner and the volume of the waste toner box must be increased. Then, the device cannot be downsized. The decrease in transfer efficiency is considered to be due to reverse polarity fog and transfer omission due to poor dispersion.

Further, in the case of color development, since toner images of four colors are superposed on the intermediate transfer member, the toner layer becomes thick, and a pressure difference between a toner layer not present or a thin place is likely to occur. Therefore, due to the toner aggregating effect, the "blankhole" phenomenon in which a part of the image is not transferred and becomes a hole is likely to occur. Furthermore, if a material having a high toner releasing effect is used for the intermediate transfer member in order to reliably perform cleaning when the image receiving paper is jammed, hollow defects will appear remarkably and the image quality will be significantly deteriorated. Further, in the case of characters, lines, etc., edge development is performed, so that the amount of toner is increased and the toner particles agglomerate due to the pressurization, so that hollow defects become more prominent. Particularly, it appears more remarkably in an environment of high humidity and high temperature.

In view of the above problems, the present invention provides a toner which is suitable for a developing method which enables further downsizing, simplification and cost reduction of an apparatus and which realizes a high image quality of high density low ground fog. With the goal.

Waste toner recycled by returning the waste toner removed in the cleaning step to the developing step for reuse is used to prevent the occurrence of filming and scratches on the photoconductor, and to suppress the change in toner composition. By,
It is an object of the present invention to provide a toner that achieves high image density and high image quality in low ground fog over a long period of time.

Even in a transfer device using a conductive elastic roller for reducing the amount of ozone generated, the purpose is to prevent roller contamination and paper stains.

Another object of the present invention is to provide a developer which can prevent hollow defects and scattering at the time of transfer by an electrophotographic method using an intermediate transfer member and can obtain high transfer efficiency.

Another object of the present invention is to provide a developer capable of preventing filming of the photoconductor and the intermediate transfer body even after long-term use.

[0057]

To solve the above problems, the toner of the present invention has the following constitution.

A toner comprising a toner base composed of at least a binder resin, colorant particles and a wax, and an external additive, wherein the binder resin comprises a wax composed of at least polyethylene. 0.5 to 10 parts by weight per 100 parts by weight of the binder resin, the wax was prepared by a thermal decomposition method, and the recovery rate was 95% or more when washed with toluene at 25 ° C. for 1 hour, and the wax was softened. The point is 80 to 140 ° C., the penetration at 25 ° C. is 8 or less, and the toner of the present invention has a specific surface area St (m ² /
g), specific surface area Sb (m ² / g) of toner base, specific surface area Sa (m ² / g) of external additive, and additive amount W (wt%) of external additive
In this case, the toner is characterized in that 0.3 ≦ (St-Sb) / (Sa * W / 100) ≦ 0.7.

Further, in the present invention, a developing step in which an electrostatic latent image on a photoconductor is visualized with toner, and a transfer step in which the visualized toner on the photoconductor is transferred to a transfer sheet by electrostatic force An electronic device having at least a cleaning step of removing toner partially remaining on the photoconductor during the transfer step from the photoconductor, and a waste toner recycling step of returning the waste toner removed in the cleaning step to the developing step for reuse. A toner used in a photographic method, the toner comprising a toner base composed of at least a binder resin, colorant particles, and a wax, and an external additive, wherein the toner is contained in the binder resin. A wax composed of at least polyethylene is contained in an amount of 0.5 to 10 parts by weight per 100 parts by weight of the binder resin, and the wax is prepared by a thermal decomposition method.
The recovery rate after washing with toluene at 1 ° C for 1 hour is 95% or more, and the softening point of the wax is 80 to 140 ° C, 25 ° C.
In the toner of the present invention, the specific surface area St (m ² / g) of the toner and the specific surface area Sb of the toner base are
(M ² / g), specific surface area Sa (m ² / g) of the external additive, when the amount of the external additive W (wt%), 0.3 ≦ (St-Sb) / (Sa * The toner is characterized in that W / 100) ≦ 0.7.

Further, in the present invention, the transfer step includes a conductive elastic roller which is in contact with the photosensitive member, and the toner which is visualized on the photosensitive member is transferred by the transfer bias voltage applied to the conductive elastic roller. It is a toner used in the electrophotographic method which is a step.

Further, in the present invention, the developing step is constituted by a two-component developing method comprising a toner and a carrier, and the surface has at least a DBP oil absorption of 60 to 400 ml / 100.
g, a specific surface area of 100 to 1300 m ² / g, and a structure in which a coating layer made of a fluorine-based resin or silicone resin containing carbon black having a pH of 8.5 or less is provided, and a volume average particle diameter is 60 to 120 μm and a volume resistance is 1 × 10 ⁵ -1
× 10 ¹⁰ Ωcm, and the amount of triboelectricity with the toner is 6 to 2
It is a toner used in an electrophotographic method using a carrier of 0 μC / g.

Further, according to the present invention, after the electrostatic latent image is formed on the moving photoconductor containing the fixed magnet, the toner is magnetically attracted to the surface of the photoconductor located in the toner hopper, and the electrostatic latent image is formed on the photoconductor. Toner is carried on the surface, the photoconductor is moved, and it is made to face the toner collecting electrode roller having a magnet inside at a position having a predetermined gap with the surface of the photoconductor to leave the toner on the image portion of the photoconductor, The toner in the image area is collected by a toner collecting electrode roller, a developing process in which a toner image visualized on the photoconductor is transferred to a transfer paper by electrostatic force, and a part of the toner remains on the photoconductor during the transfer process A toner used in an electrophotographic method, which comprises at least a cleaning step of removing toner from a photoreceptor, wherein the toner comprises a toner base composed of at least a binder resin, colorant particles, and a wax, and an external additive. From A toner made of a binder resin, wherein the binder resin contains at least 0.5 to 10 parts by weight of a wax composed of polyethylene per 100 parts by weight of the binder resin, and the wax is prepared by a thermal decomposition method, 25
The recovery rate after washing with toluene at 1 ° C for 1 hour is 95% or more, and the softening point of the wax is 80 to 140 ° C, 25 ° C.
In the toner of the present invention, the specific surface area St (m ² / g) of the toner and the specific surface area Sb of the toner base are
(M ² / g), specific surface area Sa (m ² / g) of the external additive, when the amount of the external additive W (wt%), 0.3 ≦ (St-Sb) / (Sa * The toner is characterized in that W / 100) ≦ 0.7.

Further, according to the present invention, after the electrostatic latent image is formed on the moving photosensitive member containing the fixed magnet, the toner is magnetically attracted to the surface of the photosensitive member located in the toner hopper, and Toner is carried on the surface, the photoconductor is moved, and it is made to face the toner collecting electrode roller having a magnet inside at a position having a predetermined gap with the surface of the photoconductor to leave the toner on the image portion of the photoconductor, The toner in the image area is collected by a toner collecting electrode roller, a developing process in which a toner image visualized on the photoconductor is transferred to a transfer paper by electrostatic force, and a part of the toner remains on the photoconductor during the transfer process A toner used in an electrophotographic method having at least a cleaning step of removing toner from a photoconductor and a waste toner recycling step of returning the waste toner removed in the cleaning step to a developing step again for reuse. Is a toner comprising a toner base composed of at least a binder resin, colorant particles and a wax, and an external additive, wherein the binder resin comprises a wax composed of at least polyethylene. 0.5 to 10 parts by weight per 100 parts by weight of the binder resin, the wax was prepared by a thermal decomposition method, and the recovery rate was 95% or more when washed with toluene at 25 ° C. for 1 hour, and the wax was softened. The toner of the present invention has a specific surface area St (m ² / g) of toner, and a specific surface area Sb (m ² / m ^{2 of the} toner base) of the toner of the present invention.
g), specific surface area of external additive Sa (m ² / g), and amount of external additive added W (wt%), 0.3 ≦ (St-Sb) / (Sa * W / 100) The toner is characterized in that ≦ 0.7.

Further, in the present invention, the transfer step comprises a conductive elastic roller which is in contact with the photosensitive member, and the toner which is visualized on the photosensitive member is transferred by the transfer bias voltage applied to the conductive elastic roller. It is a toner used in the electrophotographic method which is a step.

Further, in the present invention, the developing step of developing the electrostatic latent image formed on the image bearing member with the toner, and the primary transfer of the toner to the endless intermediate transfer member which is in contact with the image bearing member. And the step of performing the primary transfer step a plurality of times to form a transfer toner overlapping image, and the transfer toner overlapping image formed on the intermediate transfer member is collectively collected on the image receiving paper conveyed from the paper feeding side. A toner used in an electrophotographic method having at least a step of secondary transfer, wherein the toner is composed of a toner base composed of at least a binder resin, colorant particles, and a wax, and an external additive. A toner containing 0.5 to 10 parts by weight of wax composed of at least polyethylene in 100 parts by weight of the binder resin, and the wax is prepared by a thermal decomposition method.
The recovery rate after washing with toluene at 1 ° C for 1 hour is 95% or more, and the softening point of the wax is 80 to 140 ° C, 25 ° C.
In the toner of the present invention, the specific surface area St (m ² / g) of the toner and the specific surface area Sb of the toner base are
(M ² / g), specific surface area Sa (m ² / g) of the external additive, when the amount of the external additive W (wt%), 0.3 ≦ (St-Sb) / (Sa * The toner is characterized in that W / 100) ≦ 0.7.

Further, the present invention is a toner for use in an electrophotographic method, wherein the intermediate transfer member comprises a polycarbonate containing carbon black as a basic component.

Further, the present invention is a toner used in an electrophotographic method, which is an intermediate transfer member surface-treated with a fluororesin.

[0068]

BEST MODE FOR CARRYING OUT THE INVENTION The binder resin of the toner of the present invention includes
A vinyl polymer obtained by polymerizing or copolymerizing styrene with a vinyl monomer such as an acrylic acid alkyl ester and a methacrylic acid alkyl ester can be used. Examples of the monomer styrene constituting the binder resin include styrene, α-methylstyrene, styrene such as P-chlorostyrene, and substituted products thereof, and examples of the acrylic acid alkyl ester include acrylic acid and acrylic acid. Methyl, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, isobutyl acrylate, hexyl acrylate, and as the methacrylic acid alkyl ester, for example, methyl methacrylate, ethyl methacrylate, butyl methacrylate, Octyl methacrylate, isobutyl methacrylate, dodecyl methacrylate,
Examples include monocarboxylic acids having a double bond such as hexyl methacrylate and substituted products thereof.

When using this copolymer, it is preferable to contain 50 to 95% by weight of a styrene component. When the proportion of styrene is less than 50% by weight, the melting property of the toner is inferior, the fixing property of the toner becomes insufficient, and the pulverizability deteriorates.

For the production of these copolymers, bulk polymerization,
Known polymerization methods such as solution polymerization, suspension polymerization and emulsion polymerization are used.

As the binder resin, other known polymers or copolymers such as polyester resin, epoxy resin, polyurethane resin, etc. may be used, if necessary, in addition to the above main components. You can also

The melt index of the binder resin, which shows the viscosity at the time of melting, is preferably 4 to 40 g / 10 min at 150 ° C. When the melt index of the binder resin is 4 g / 10 min or less, the pulverizability during toner production is poor and the productivity is degraded. If it is more than 40 g / 10 min, the viscosity of the binder resin is lowered at the time of melting, and the kneading force does not act, so that the wax component cannot be dispersed, and the resin component adheres to the surface of the carrier and the surface of the toner carrier, and the charge amount of the toner decreases.

The binder resin has a glass transition point, a softening point, a weight average molecular weight, a number average molecular weight, and a low molecular weight component and a high molecular weight component, in order to enhance the penetrating power into paper and maintain the high temperature offset resistance. It is necessary to specify the composition ratio.

The glass transition point is preferably 50 to 70 ° C., the weight average molecular weight Mw is 100,000 or more, and the number average molecular weight Mn is 2000 or more and 20,000 or less. The composition ratio (HP / LP ratio) of the high molecular weight component and the low molecular weight component is preferably from 10:90 to 50:50. The softening point of the binder resin is 110 to 160 ° C, preferably 110 to 150 ° C, more preferably 115 to 140 ° C.
° C. When the temperature is 110 ° C or lower, the strength of the binder resin becomes weak. If it is 160 ° C or higher, the fixing property is deteriorated.

As the magnetic powder, metal powder such as iron, manganese, nickel and cobalt, ferrite powder such as iron, manganese, nickel, cobalt and zinc are used. The average particle size of the powder is preferably 1 μm or less, and particularly preferably 0.6 μm or less.

As the pigment or dye used for the colorant particles, carbon black, iron black, graphite, nigrosine, a metal complex of azo dye, phthalocyanine blue,
DuPont oil red, aniline blue, benzine yellow, rose bengal, and mixtures thereof can be used.

As the wax, a polyethylene wax or a mixed wax with other wax such as polypropylene, polybutene or polyhexene can be used. In this case, the polyethylene wax must be contained in an amount of 50% by weight or more.

The wax is mixed with the binder resin in the mixing treatment step, but in order to improve the dispersibility, a part or the entire amount of the wax may be contained in the binder resin in advance. In this case, the content may be added by dissolving the resin with a solvent during or after the polymerization of the binder resin.

As the external additive, fine powders of metal oxides such as silica, alumina, titania, zirconia, magnesia, ferrite and magnetite, carbides such as tungsten carbide, other nitrides, barium titanate, calcium titanate, titanic acid. Titanates such as strontium,
Zirconates such as barium zirconate, calcium zirconate, and strontium zirconate, or mixtures thereof are used. The external additive may be subjected to a surface treatment such as a hydrophobic treatment, if necessary.

The toner of the present invention may further contain a releasing agent, a fluidity auxiliary agent such as a fine powder of an organic material, a charging auxiliary agent, and a cleaning auxiliary agent, if necessary.

The toner of the present invention is manufactured by the following method. The toner is manufactured by mixing, kneading, pulverizing, classifying, and externally treating. Other methods such as a polymerization method may also be used.

The mixing treatment is carried out by using a binder resin, colorant particles,
Wax and other charge control agents added as necessary,
This is a treatment for uniformly dispersing an internal additive such as a release agent with a mixer equipped with a stirring blade, and a known treatment method is used.

In the embodiment, the Henshur mixer FM-2 is used.
OB (manufactured by Mitsui Miike Kakoki Co., Ltd.) is used for the mixing treatment.

In the kneading treatment, the mixed material is heated to disperse the internal additive in the binder resin by a shearing force. For this kneading, a three-roll type, a uniaxial screw type, a biaxial screw type is used. It is possible to use a known heating kneader that heats a kneaded material such as a mold or a Banbury mixer and applies a shearing force to knead it. In the example, a twin-screw kneader PCM
The mixture is heated and kneaded using -30 (manufactured by Ikegai Co., Ltd.).

Next, the mass obtained by the kneading process is roughly crushed by a cutter mill or the like and then finely crushed. For this fine pulverization, an airflow type pulverizer represented by a jet mill pulverizer or a mechanical pulverizer represented by a rotor type pulverizer can be used.
Further, the particles are classified using a classifier, and fine powder particles are cut to obtain a desired particle size distribution. For the classification, a mechanical classification method in which classification is performed using the centrifugal force of a rotating rotor can also be used. In the examples, the kneaded product was finely pulverized by a jet mill pulverizer IDS-2 type (manufactured by Nippon Pneumatic Mfg. Co., Ltd.), and then the finely pulverized product was classified by an air stream classifier DS-2 type (Nippon Pneumatic Mfg. Co., Ltd.) (Manufactured by Mitsui Chemical Co., Ltd.) and fine powder was cut to obtain toner particles having an average particle size of 8 μm. The toner obtained at this stage is called a toner base to distinguish it from the finished toner.

In the external addition treatment, an external additive is added to the toner base,
This is a process of mixing. A known mixer can be used as the mixer.

The toner of the present invention has a specific surface area St
(M ² / g), specific surface area Sb (m ² / g) of the toner base, the specific surface area Sa (m ² / g) of the external additive, the addition amount of the external additive W (w
t%), 0.3 ≦ (St-Sb) / (Sa * W / 100) ≦ 0.7.

Therefore, it is necessary to control the temperature inside the mixer tank to 35 ° C. or lower. If the temperature inside the tank is 35 ° C or higher,
Since the wax adheres to the tank wall and takes in the external additive, the amount of the external additive cannot be controlled to vary. The control of (general formula 1) is
It was performed by adjusting the peripheral speed of the blades of the mixer and the mixing time.
Although the general formula 1 decreases as the blade peripheral speed increases,
At a peripheral speed of 45 m / s or more, the toner base itself is broken into fine powder and the toner fluidity is remarkably reduced. Also,
When the mixing time is 30 min or more, heat generation cannot be suppressed even if the peripheral speed is 45 m / s or less.

In the examples, Henshur Mixer FM-20B (Mitsui Miike Kakoki Co., Ltd.) was obtained by wall cooling this mixture.
However, the known processing methods such as super mixer (manufactured by Kawata Co., Ltd.), PS mixer (manufactured by Shinko Pantec Co., Ltd.), Redige mixer, ball mill, attritor mill, etc., which can control the temperature, were used. You may use.

The carrier used in the present invention is prepared by providing a resin coating layer on the surface of ferrite particles. Ferrite is mainly composed of Fe ₂ O ₃ and contains NiO and Cu.
O, CoO, MgO, ZnO, MnCO ₃ , BaCO ₃ ,
SrCO ₃ is mixed and used as a raw material.

The ferrite particles may be produced by either a wet method or a dry method, but the dry method is generally used. In the dry method, raw materials are mixed and then calcined, finely pulverized in water with a ball mill or the like, and PVA (polyvinyl alcohol) as a binder, a defoaming agent and a dispersant are added to obtain a granulation slurry. This slurry is granulated while being dried by heating with a spray dryer, and then subjected to main firing. Main firing is 900-140
It is carried out at 0 ° C. for 10 to 30 hours, then crushed and classified to obtain ferrite particles.

For the resin coating layer, known methods such as a spray method and a dipping method are used. The coating amount is 0.3 to 1.2 wt% of the carrier particle weight.

The resin used for the resin coating layer is a fluorine resin or a silicone resin. As the carbon black contained in the resin coating layer, carbon black produced by various methods is used, but oil furnace carbon or acetylene black is preferable. Further, the surface of carbon black may be used after being grafted or may be used after being subjected to an oxidation treatment.

(Embodiment 1) An electrophotographic method using a toner according to the present invention includes a developing step of visualizing an electrostatic latent image on a photoconductor with the toner and a visible image on the photoconductor. It is configured to have at least a transfer step of transferring the converted toner to a transfer sheet by electrostatic force and a cleaning step of removing the toner partially remaining on the photoconductor during the transfer step from the photoconductor.

In the developing step, the toner needs to have an appropriate positive or negative charge. The toner is mixed with frictionally charged powder called a carrier, obtains a charge, and is transported to a developing unit. In order to obtain good print quality over a long period of time, it is required that neither the toner nor the carrier deteriorates.

In the toner of the present invention, the binder resin contains a wax composed of at least polyethylene.
0.5 to 10 parts by weight per 100 parts by weight, specific surface area St (m ² / g) of toner, specific surface area Sb of toner base
(M ² / g), specific surface area Sa (m ² / g) of the external additive, when the amount of the external additive W (wt%), 0.3 ≦ (St-Sb) / (Sa * Since W / 100) ≦ 0.7 (Equation 1), the wax on the surface of the toner base is covered with the external additive. It is considered that this is because the mechanical stress applied during external addition preferentially causes the external additive to be embedded and fixed in the wax portion which is softer than the binder resin, and is fixed.

The difference between the specific surface area St of the toner and the specific surface area Sb of the toner base shows the specific surface area of the external additive exposed from the surface of the toner base. Therefore, it can be said that (Equation 1) represents the ratio of the external additives that are not embedded in the toner base.

For this reason, when the external additive is appropriately exposed, the chance of the wax coming into direct contact with the photoconductor at the time of non-fixing is reduced, and photoconductor filming due to the wax can be suppressed. At the time of fixing, heat and pressure are applied to the toner at the same time, so that the wax is melted and a large amount is present on the surface of the fixed image, which contributes to the improvement of the fixing property.

When the value of (Equation 1) is less than 0.3, the external additive is buried too much on the surface of the toner base, and filming of the photoreceptor occurs. Further, the effect of improving the fluidity of the toner cannot be obtained. On the contrary, when the value of (Equation 1) is larger than 0.7, the amount of the external additive existing on the surface of the toner base is excessive.
Therefore, the fusion of the toner particles is prevented, so that the toner storability and the filming resistance are improved, but the fixing property is deteriorated.

The wax was prepared by a thermal decomposition method and had a recovery of 95% or more when washed with toluene at 25 ° C. for 1 hour, had a softening point of 80 to 140 ° C. and a penetration of 8 at 25 ° C. It is the following. Therefore, it has both the effect of improving the toner fixing property due to the low softening point characteristic and the photoconductor filming characteristic due to the low content of the low boiling point component. This is because a low-boiling component is vaporized due to the use of a thermal decomposition reaction during the preparation of the wax, and is hardly contained in the wax. It is considered that most of the substances that are melted in toluene and removed are low-boiling components in the wax. Therefore, it can be said that the wax having a high recovery rate after washing with toluene has a low low-boiling component content.

When the softening point of the wax is 80 ° C. or lower, the storability of the toner decreases. In addition, the wax component adheres to the surface of the carrier and the surface of the toner carrier. At 140 ° C. or higher, the toner does not exude to the surface of the fixed image during toner fixing, and the effect of improving the fixability is small.

If the penetration of the wax at 25 ° C. is 8 or more, the fluidity of the toner is lowered, the mixing with the carrier is not sufficiently performed, and uniform charging cannot be performed.

When the amount of wax added is 0.5 part or less, the effect of improving fixability is not observed. Further, since the external additive is not buried in the wax on the toner surface, a free external additive is generated, and the toner fluidity becomes unstable and the image deteriorates.

When the amount is 10 parts or more, the wax cannot be well dispersed in the toner when the toner is prepared, and the charge amount becomes uneven.

When the wax is prepared by a method other than the thermal decomposition method, for example, a low pressure polymerization method, it is contained even when the recovery rate after washing with toluene at 25 ° C. for 1 hour is 95% or more. Since the molecular weight of the low boiling point component is low, filming occurs even in a small amount. In addition, even if the wax is produced by a thermal decomposition method,
95% recovery rate when washed with toluene at ℃ for 1 hour
In the case of the following, the fluidity of the toner is lowered and filming occurs.

(Embodiment 2) An electrophotographic method using a toner according to the present invention includes a developing step of visualizing an electrostatic latent image on a photoconductor with the toner, and a visible image on the photoconductor. The transfer process of transferring the removed toner to the transfer paper by electrostatic force, the cleaning process of removing the toner partially remaining on the photoconductor during the transfer process from the photoconductor, and the waste toner removed by the cleaning process are returned to the developing process again and re-used And a waste toner recycling step to be used.

Further, the developing step is constituted by a two-component developing method comprising a toner and a carrier, and the surface has at least a DBP oil absorption of 60 to 400 ml / 100 g, a specific surface area of 100 to 1300 m ² / g, and a carbon black having a pH of 8.5 or less. Has a structure in which a coating layer made of a fluorine-based resin or silicone resin containing
Volume resistance of 1 × 10 ⁵ to 1 × 10 ¹⁰ Ω at 0 to 120 μm
cm, and the amount of triboelectricity with the toner is 6 to 20 μC / g
This is a configuration using a carrier.

Therefore, it is required that the charge applied to the toner from the carrier does not fluctuate so much that the toner does not deteriorate due to recycling and the charge amount does not change.

In the toner of the present invention, the binder resin contains a wax composed of at least polyethylene.
0.5 to 10 parts by weight per 100 parts by weight, specific surface area St (m ² / g) of toner, specific surface area Sb of toner base
(M ² / g), specific surface area Sa (m ² / g) of the external additive, when the amount of the external additive W (wt%), 0.3 ≦ (St-Sb) / (Sa * Since W / 100) ≦ 0.7 (Equation 1), the external additive is fixed on the surface of the toner base and the released external additive is small. Therefore, the fixability and the storability are high, and when the waste toner is recycled, the released external additive is not mixed with the toner again and the toner characteristics are not changed.

If the value of (Equation 1) is less than 0.3, the external additive is buried too much on the surface of the toner base, so that the wax often contacts the photoconductor and the photoconductor filming occurs. Further, since the effect of improving the fluidity of the toner cannot be obtained, the toner circulation in the waste toner recycling step is not performed well. On the other hand, when the value of (Equation 1) is larger than 0.7, the amount of the external additive existing on the surface of the toner base is excessive so that the external additive is liberated and the fixing property is hindered. The content of the additive varies and the image quality is degraded. In addition, the released external additive aggregates and causes scratches on the surface of the photoconductor to trigger filming of the photoconductor.

When the wax was prepared by a thermal decomposition method and was washed with toluene at 25 ° C. for 1 hour, the recovery rate was 95% or more, the softening point was 80 to 140 ° C., and the penetration at 25 ° C. was 8%. It is the following. Therefore, it has both the effect of improving the toner fixing property due to the low softening point characteristic and the photoconductor filming characteristic due to the low content of the low boiling point component. Further, in the recycling step, the phenomenon that wax adheres to the toner transport path is suppressed, and toner can be transported satisfactorily. This is because wax is less likely to be released in the cleaning step due to the small amount of the low boiling point component.

When the softening point of the wax is 80 ° C. or lower, even if the wax surface is covered with the external additive, the toner is aggregated due to the exudation of the wax component and the storability is deteriorated.
Under high temperature and high humidity, transportability for recycling cannot be fully performed due to deterioration of fluidity. At 140 ° C. or higher, the toner does not exude to the surface of the fixed image during toner fixing, and the effect of improving the fixability is small.

If the penetration of the wax at 25 ° C. is 8 or more, the fluidity of the toner is lowered, the recyclability is poor, and uniform charging cannot be performed.

If the amount of wax added is 0.5 part or less, the effect of improving fixability is not observed. At 10 parts or more, the amount of free wax increases, and when recycled, the wax content in the toner increases, and fog increases.

When the wax is prepared by a method other than the thermal decomposition method, for example, a low pressure polymerization method, it is contained even when the recovery rate after washing with toluene at 25 ° C. for 1 hour is 95% or more. Since the low-boiling point component has a low molecular weight, it adheres to the cleaning section, making it impossible to recover the toner and prevent recycling. Even when the wax is prepared by a thermal decomposition method, if the recovery rate after washing with toluene at 25 ° C. for 1 hour is 95% or less, the fluidity of the toner is lowered and the wax during recycling is reduced. The toner transportation is not stable and the image density is not stable.

The carbon black contained in the carrier surface coating layer has a DBP oil absorption of 60 to 400 ml / 100 g,
Since the specific surface area is 100 to 1300 m ^{2 /} g and the pH is 8.5 or less, the mixing property with the fluorine-based resin or the silicone-based resin forming the coating layer is good. For this reason, the amount of charge given to the toner from the carrier is stably controlled, and a good image can be obtained for a long period without causing charge-up or charge amount reduction.

A fluorine resin or a silicone resin is used as the coating layer resin. This is because the phenomenon in which the toner and its components adhere to the carrier surface over a long period of use and the charge applying ability and the fluidity decrease, so-called spent, is suppressed. The spent phenomenon becomes remarkable when waste toner is recycled or a low softening point substance is added to the toner. Also, when the waste toner is recycled without peeling of the surface coating layer from the carrier, no foreign matter is mixed into the toner.

The DBP oil absorption is the same as that of carbon black.
This value indicates the length of the structure.
Long dispersion and good dispersibility in resin
Is shown. When DBP oil absorption is less than 60ml / 100g
Has poor dispersibility in the resin for the coating layer, and the toner is evenly distributed.
Can not be charged. Also 400ml / 100g
Above, the viscosity of the coating resin increases, and the
Uniform coating on the rear surface cannot be performed. Specific surface area is particle
It is an index showing the diameter and shape. Specific surface area 100m ^Two/ G or less
Below, the ability to charge the toner from the carrier is insufficient
As a result, the toner charge decreases. 1300m^Two/ G or less
Above, uniform dispersion in the resin of the coating layer cannot be performed.

PH of carbon black is related to charging, and when PH is 8.5 or more, it becomes difficult to positively charge the toner, so that low-charged toner is generated and fog is generated on an image. To do.

The volume average particle diameter of the carrier is 60 to 1
Since the thickness is 20 μm, the carrier does not adhere to the photoreceptor to cause scratches and does not promote filming of the photoreceptor by the wax. Further, the frictional charge amount with the toner is 6 to 2
Since it is 0 μC / g, there is no toner charged to the negative polarity even after recycling, and there is no increase in background fog.

When the volume average particle diameter of the carrier is 60 μm or less, the carrier adheres to the photosensitive member and causes scratches. 120
Above μm, the toner conveying force of the carrier is low, and the image density decreases. If the amount of frictional charge with the toner is 6 μC / g or less, negatively charged toner is generated, and if waste toner is recycled, fog increases and image quality is greatly reduced. 20 μC / g
Above, a practical image cannot be obtained due to low image density.

The volume resistance of the carrier is 1 × 10 ⁵ to 1 × 1.
Since it is 0 ¹⁰ Ωcm, a stable image can be obtained regardless of the environment. For 1 × 10 ⁵ Ωcm or less, when the carrier resistance under high temperature and high humidity conditions was reduced, decreased the amount of toner charge violently, also 1 × 10 ¹⁰ not less than [Omega] cm, reproducibility of the solid image edge effect becomes stronger poor Become.

(Embodiment 3) An electrophotographic method using a toner according to the present invention includes a developing step of visualizing an electrostatic latent image on a photoconductor by the toner and a conductive step of contacting the photoconductor. Equipped with an elastic roller, the transfer paper is inserted between the photoconductor and the conductive elastic roller, and the toner that is visualized on the photoconductor is electrostatically transferred by the transfer bias voltage applied to the conductive elastic roller. It is configured to have at least a transfer step of transferring to paper and a cleaning step of removing the toner partially remaining on the photoconductor during the transfer step from the photoconductor.

In the case of corona transfer, when the toner charge amount is low or the polarity is opposite to the predetermined value, the amount of toner that is not transferred in the transfer step increases. However, in the case of roller transfer, contact force causes a mechanical force in addition to the electric field force, so that a reverse-polarity toner that is not originally transferred tends to be transferred. For this reason, fogging increases, and toner is contaminated on the surface of the transfer roller when the paper is not passed, and the back surface of the copy paper is soiled.

In the toner of the present invention, the binder resin contains a wax composed of at least polyethylene.
0.5 to 10 parts by weight per 100 parts by weight, specific surface area St (m ² / g) of toner, specific surface area Sb of toner base
(M ² / g), specific surface area Sa (m ² / g) of the external additive, when the amount of the external additive W (wt%), 0.3 ≦ (St-Sb) / (Sa * W / 100) ≦ 0.7 (Equation 1) Therefore, the fixability and storability are high,
There is no occurrence of filming due to wax. Also,
Since the wax holds the external additive, the external additive is less released from the toner base, and the toner charge amount is high and maintained stably. Therefore, the generation of reverse polarity toner is small and the transfer efficiency is high. Further, the released external additive does not adhere to the transfer roller to cause an image defect.

When the value of (Equation 1) is less than 0.3, the external additive is buried too much on the surface of the toner base, so that the wax often comes into direct contact with the photoconductor and the photoconductor filming occurs. . Then, a fine electric discharge occurs between the filmed surface of the photoconductor and the transfer roller due to the unevenness of the surface of the photoconductor, thereby deteriorating the image quality.

On the other hand, when the value of (Equation 1) is larger than 0.7, the amount of the external additive present on the surface of the toner base is excessive, and the external additive is liberated to impair the fixing property. In addition, the liberated external additive aggregates, causing scratches on the surface of the photoconductor and causing transfer failure.

The wax was prepared by a thermal decomposition method, and the recovery rate when it was washed with toluene at 25 ° C. for 1 hour was 95% or more, the softening point was 80 to 140 ° C., and the penetration at 25 ° C. was 8%. It is the following. Therefore, it has both the effect of improving the toner fixing property due to the low softening point property, the anti-photosensitive filming property due to the low content of the low boiling point component, and the effect that the external additive is appropriately buried in the wax on the surface of the toner base. .

When the softening point of the wax is 80 ° C. or lower, the toner is thermally agglomerated at the cleaning blade portion and the photoconductor filming occurs, so that the roller transfer is stable even when the wax surface is covered with the external additive. I can not do it.
At 140 ° C. or higher, even when the amount of the external additive is small, the toner does not exude to the surface of the fixed image at the time of fixing the toner, and the effect of improving the fixing property is small.

If the penetration of the wax at 25 ° C. is 8 or more, the external additive will be embedded in the toner base so much that the fluidity of the toner will be deteriorated, so that uniform charging cannot be carried out and the toner having the opposite polarity can be obtained. And the transfer efficiency decreases. In the case of roller transfer, if the fluidity of the toner is low, the central portion of the line image is not transferred, that is, a so-called “missing” phenomenon occurs. This is considered to be due to the fact that the toner having low fluidity is softly aggregated when pressure is applied to the toner during roller transfer.

If the amount of wax added is 0.5 parts or less, the effect of improving the fixability cannot be seen. At 10 parts or more, the amount of free wax increases, the amount of toner of opposite polarity increases, and the amount of toner consumed per unit print increases.

When the wax is prepared by a method other than the thermal decomposition method, for example, a low pressure polymerization method, it is contained even when the recovery rate after washing with toluene at 25 ° C. for 1 hour is 95% or more. Since the molecular weight of the low boiling point component is low, filming occurs on the photoconductor and roller transfer cannot be performed.
Even when the wax is prepared by a thermal decomposition method, if the recovery rate after washing with toluene at 25 ° C. for 1 hour is 95% or less, the toner fluidity is low and the voids during roller transfer occur. Occurs.

The volume average particle size of the carrier is 60 to 1
Since the thickness is 20 μm, the carrier does not adhere to the photoreceptor to cause scratches, and does not promote filming of the photoreceptor by the wax or discharge from the transfer roller. For the surface coating layer of the carrier, a fluorine resin or a silicone resin is used. Therefore, the surface coating layer is not peeled off from the carrier, and the triboelectric charge amount with the toner is 6 to 20 μC / g.
Even in the configuration using the charging roller, there is no toner charged negatively and there is no increase in ground fog.

When the volume average particle diameter of the carrier is 60 μm or less, the carrier adheres to the photosensitive member and causes scratches. 120
Above μm, the toner conveying force of the carrier is low, and the image density decreases. When the frictional charge amount with the toner is 6 μC / g or less, negatively charged toner is generated, and the image quality is greatly reduced. 20
Above μC / g, the image density is so low that a practical image cannot be obtained.

(Embodiment 4) In the electrophotographic method using the toner according to the present invention, an electrostatic latent image is formed on a photoreceptor containing a fixed magnet, and the toner is sprinkled on the electrostatic latent image to magnetically adhere the toner. In this state, the toner is carried and conveyed to a collecting section facing the electrode roller, an AC bias is applied to the electrode roller, and the non-image area toner on the photoconductor is removed by electrostatic force and magnetic force.

Therefore, the electrophotographic method presented in the present invention can be made more compact and high-performance by adding to the cascade development method a structure in which a magnet is installed inside the photosensitive member and a structure in which an AC voltage is applied to the electrodes. It was done.

In this electrophotographic method, the development is almost completed when the toner is first sprinkled on the photosensitive member. It is the photoconductor that carries and carries the toner from the toner hopper to the developing unit, and the electrode roller unit functions to collect the toner in the non-image portion of the electrostatic latent image and to circulate the toner in the toner container. . The bare surface of the electrode roller that does not carry the toner layer faces the photoconductor.

Since the electrophotographic method using the toner of the present invention has a simple structure, there are few toner charging opportunities and it is difficult to obtain high charging characteristics. Further, since the toner and the photoconductor are in long contact during development, toner filming is likely to occur on the photoconductor.

Further, since the toner is held in the narrow gap between the photoconductor and the electrode roller, the toner is required to have high storability. This is because if the toner aggregates and blocks at the gap, no printing can be performed at all because there is no loosening action at the layer regulating portion.

The electrophotographic method in which the toner of the present invention is used has a structure in which magnetic powder is contained in the toner in order to carry the toner by magnetic force. Therefore, the ratio of the binder resin in the toner particles is relatively small, and the fixing performance is reduced.

In the toner of the present invention, the binder resin contains a wax composed of at least polyethylene.
0.5 to 10 parts by weight per 100 parts by weight, specific surface area St (m ² / g) of toner, specific surface area Sb of toner base
(M ² / g), specific surface area Sa (m ² / g) of the external additive, when the amount of the external additive W (wt%), 0.3 ≦ (St-Sb) / (Sa * W / 100) ≦ 0.7 (Equation 1) Therefore, since the wax reduces the frictional resistance on the surface of the fixed image, the toner having a constitution containing the magnetic powder also has a good fixing property. Further, since the wax on the surface of the toner base retains the external additive, the external additive is not released from the toner base, and the toner charge amount is kept high and stable. Is less likely to occur. Furthermore, since the toner has a high storability, the toner does not block between the photoconductor and the electrode roller.

If the value of (Equation 1) is less than 0.3, the external additive is buried too much on the surface of the toner base, so that the wax often contacts the photoconductor and the photoconductor filming occurs.

Further, the toner storability is poor, and toner blocking occurs in the narrow gap between the photoconductor and the electrode roller, making printing impossible.

On the other hand, when the value of (Equation 1) is larger than 0.7, the amount of the external additive present on the surface of the toner base is large and the external additive is liberated to impair the fixing property. Further, the released external additive aggregates and is not crushed because there is no layer control portion in the developing device, so that the image is developed as a white spot at the tip of the black solid image.

The wax was prepared by a thermal decomposition method and had a recovery of 95% or more when washed with toluene at 25 ° C. for 1 hour, and had a softening point of 80 to 140 ° C. and a penetration of 8 at 25 ° C. It is the following. Therefore, it has both the effect of improving the toner fixing property due to the low softening point property, the anti-photosensitive filming property due to the low content of the low boiling point component, and the effect that the external additive is appropriately buried in the wax on the surface of the toner base. . Further, when the toner circulates in the toner reservoir, the toner does not aggregate due to the low boiling point component of the wax.

When the softening point of the wax is 80 ° C. or lower, toner particles aggregate at the cleaning blade portion to cause photoreceptor filming even if the wax surface is covered with the external additive, resulting in image defects. At 140 ° C. or higher, even when the amount of the external additive is small, the toner does not exude to the surface of the fixed image at the time of fixing the toner, and the effect of improving the fixing property is small.

If the penetration of the wax at 25 ° C. is 8 or more, the fluidity of the toner is lowered, so that uniform charging cannot be carried out and the amount of the reverse polarity toner increases. Further, when circulating in the toner reservoir, filming occurs on both the photoconductor and the electrode roller, resulting in a poor image with a lot of fog.

If the amount of wax added is 0.5 parts or less, the effect of improving fixability is not observed. Since the compatibility with the binder resin is poor, if the amount of wax added is 10 parts or more, the amount of free wax increases and the storage stability decreases.

When the wax is prepared by a method other than the thermal decomposition method, for example, a low-pressure polymerization method, it is contained even if the recovery rate after washing with toluene at 25 ° C. for 1 hour is 95% or more. Since the molecular weight of the low boiling point component is low, the toner agglomerates in the toner reservoir and filming is performed on the photoconductor, so that image printing cannot be performed. Also, even if the wax was created by a pyrolysis method,
The recovery rate is 9 when washed with 25 ° C toluene for 1 hour.
When the content is 5% or less, the wax component is melted due to heat generation in the mixing step for preparing the toner containing magnetic powder, and the mixing cannot be sufficiently performed. Therefore, the magnetic powder is not well dispersed in the toner, and the background fog occurs. Since the magnetic powder has a large specific gravity, it is considered that the impact force is large and heat is generated in the mixing process.

(Fifth Embodiment) Further, in the electrophotographic method using the toner of the present invention, a non-contact type photosensitive member containing a fixed magnet and an electrode roller having a magnet opposed to the photosensitive member with a predetermined gap therebetween are provided. It is composed of a developing process for removing unnecessary toner in the image area and a waste toner recycling process. In the development process, the electrode roller and the photoreceptor are rotating in opposite directions. Therefore, even if sudden foreign matter enters the collection site where the photoreceptor and the electrode roller face each other or the toner aggregates, Therefore, it is a configuration that can be immediately removed from the collection unit. In the configuration in which the waste toner is recycled, the paper dust and the like contained in the waste toner is quickly removed, so that it does not affect the image.

The electrophotographic method in which the toner of the present invention is used has a structure in which the toner is in contact with the photosensitive member for a long time and the toner is recycled, so that filming is likely to occur due to loose substances from the toner.

In the toner of the present invention, the binder resin contains a wax composed of at least polyethylene.
0.5 to 10 parts by weight per 100 parts by weight, specific surface area St (m ² / g) of toner, specific surface area Sb of toner base
(M ² / g), specific surface area Sa (m ² / g) of the external additive, when the amount of the external additive W (wt%), 0.3 ≦ (St-Sb) / (Sa * Since W / 100) ≦ 0.7 (Equation 1), the wax reduces the frictional resistance on the surface of the fixed image, so that the toner having magnetic powder also has a good fixing property. Further, since the wax on the surface of the toner base retains the external additive, the external additive is not released from the toner base, and even when the waste toner is recycled, the toner charge amount is kept high and stable, and the charging opportunity is small. Even in the developing method, generation of reverse polarity toner is small. Further, since the toner has a high storability, the toner does not block between the photoconductor and the electrode roller or in the transport pipe during the recycling process.

If the value of (Equation 1) is less than 0.3, the external additive is buried too much on the surface of the toner base, so that the wax often comes into contact with the photoconductor and the photoconductor filming occurs. On the other hand, when the value of (Equation 1) is larger than 0.7, the amount of the external additive existing on the surface of the toner base is excessive, and the external additive is liberated to impair the fixing property. Further, the released external additive is agglomerated and is developed as a white spot on the tip of the black solid image because there is no layer control portion in the developing device.

When the wax was prepared by a thermal decomposition method and was washed with toluene at 25 ° C. for 1 hour, the recovery rate was 95% or more, the softening point was 80 to 140 ° C., and the penetration was 8 at 25 ° C. It is the following. Therefore, it has both the effect of improving the toner fixing property due to the low softening point property, the anti-photosensitive filming property due to the low content of the low boiling point component, and the effect that the external additive is appropriately buried in the wax on the surface of the toner base. . Further, when the toner circulates in the toner reservoir, the toner does not aggregate due to the low boiling point component of the wax.

Furthermore, in the toner containing magnetic powder, a phenomenon occurs in which the magnetic powder is separated from the toner due to external stress during cleaning or the like. This phenomenon is remarkable when the dispersion of the magnetic powder in the toner is poor. Since the separated magnetic powder is fine, it is difficult to clean the magnetic powder from the surface of the photoreceptor, causing image defects. When recycling, toner is repeatedly stressed,
This phenomenon becomes significant. The toner of the present invention does not melt the wax due to heat generation during the preliminary mixing in the toner preparation process and has high toner storability and fluidity and is stable, so that separation of magnetic powder is small even when recycled.

When the softening point of the wax is 80 ° C. or lower, toner particles are aggregated at the cleaning blade portion and photoconductor filming occurs even if the wax surface is covered with the external additive, resulting in image defects. At 140 ° C. or higher, even when the amount of the external additive is small, the toner does not exude to the surface of the fixed image at the time of fixing the toner, and the effect of improving the fixing property is small.

If the penetration of the wax at 25 ° C. is 8 or more, the fluidity of the toner is lowered, so that uniform charging cannot be carried out and the amount of the reverse polarity toner increases. Further, when circulating in the toner reservoir, filming occurs on both the photoconductor and the electrode roller, resulting in a poor image with a lot of fog.

If the amount of wax added is 0.5 parts or less, the effect of improving fixability is not observed. Since the compatibility with the binder resin is poor, if the amount of wax added is 10 parts or more, the amount of free wax increases and the storage stability decreases.

(Embodiment 6) A developing step of removing unnecessary toner in a non-image area by a photoconductor containing a fixed magnet, and an electrode roller having a magnet facing the photoconductor with a predetermined gap, and a photoconductor. A conductive elastic roller abutting on the upper surface is provided, and a transfer paper is inserted between the photosensitive member and the conductive elastic roller, and a visible image is formed on the photosensitive member by a transfer bias voltage applied to the conductive elastic roller. The cleaning process includes a transfer process of transferring toner onto a transfer sheet by electrostatic force and a cleaning process. Since both the toner and the transfer roller are in contact with the photosensitive member for a long period of time, if filming occurs on either side, it will appear as a large defect on the image.

In the toner of the present invention, the binder resin contains a wax composed of at least polyethylene.
0.5 to 10 parts by weight per 100 parts by weight, specific surface area St (m ² / g) of toner, specific surface area Sb of toner base
(M ² / g), specific surface area Sa (m ² / g) of the external additive, when the amount of the external additive W (wt%), 0.3 ≦ (St-Sb) / (Sa * Since W / 100) ≦ 0.7 (Equation 1), the wax reduces the frictional resistance on the surface of the fixed image, so that the toner having magnetic powder also has a good fixing property. Further, since the wax on the surface of the toner base retains the external additive, the external additive is not released from the toner base, and the toner charge amount is kept high and stable. Is less likely to occur. Therefore, not only is roller transferability high, but roller surface contamination by free external additives does not occur, and stable transfer is performed over a long period of time. Furthermore, since the toner has a high storability, the toner does not block between the photoconductor and the electrode roller.

If the value of (Equation 1) is less than 0.3, the external additive is buried too much on the surface of the toner base, so that the wax often contacts the photoconductor and the photoconductor filming occurs. On the other hand, when the value of (Equation 1) is larger than 0.7, the amount of the external additive existing on the surface of the toner base is excessive, and the external additive is liberated to impair the fixing property. Further, the released external additive is agglomerated and is developed as a white spot on the tip of the black solid image because there is no layer control portion in the developing device.

When the wax was prepared by a thermal decomposition method and was washed with toluene at 25 ° C. for 1 hour, the recovery rate was 95% or more, the softening point was 80 to 140 ° C., and the penetration was 8 at 25 ° C. It is the following. Therefore, it has both the effect of improving the toner fixing property due to the low softening point property, the anti-photosensitive filming property due to the low content of the low boiling point component, and the effect that the external additive is appropriately buried in the wax on the surface of the toner base. . Further, when the toner circulates in the toner reservoir, the toner does not aggregate due to the low boiling point component of the wax.

In the developing system which is less likely to be charged, since the external additive is appropriately buried in the toner base, the released external additive does not reversely charge the toner and high transfer efficiency can be obtained.

When the softening point of the wax is 80 ° C. or lower, the toner particles agglomerate with each other at the cleaning blade portion to cause filming on the photosensitive member even if the wax surface is covered with the external additive, resulting in an image defect. At 140 ° C. or higher, even when the amount of the external additive is small, the toner does not exude to the surface of the fixed image at the time of fixing the toner, and the effect of improving the fixing property is small.

If the penetration of the wax at 25 ° C. is 8 or more, the fluidity of the toner is lowered, so that uniform charging cannot be carried out and the amount of the reverse polarity toner increases. Further, when circulating in the toner reservoir, filming occurs on both the photoconductor and the electrode roller, resulting in a poor image with a lot of fog.

When the amount of wax added is 0.5 part or less, the effect of improving fixability is not observed. Since the compatibility with the binder resin is poor, if the amount of wax added is 10 parts or more, the amount of free wax increases and the storage stability decreases.

(Embodiment 7) In the electrophotographic method using the toner of the present invention, the developing step of visualizing the electrostatic latent image formed on the image bearing member with the toner, and applying the toner to the image bearing member. A step of primary transfer to an endless intermediate transfer member in contact with
A step of operating the primary transfer step a plurality of times to form a transferred toner overlapping image, and a step of secondarily transferring the transferred toner overlapping image formed on the intermediate transfer member to the image receiving paper conveyed from the paper feeding side at once. It consists of a process and.

In the structure using the intermediate transfer member, the transfer efficiency is improved by using the toner of the present invention having high toner fluidity and the structure in which the wax is not exposed. In particular, part of the image is not transferred and becomes holes due to the toner aggregation effect. "
The phenomenon of “blind void” is reduced. It can be inferred that the aggregation of the toner was alleviated.

Furthermore, since the external additive is embedded in the toner base, the release of the external additive is reduced, and the occurrence of scratches and filming due to the external additive on the intermediate transfer member using a belt or the like can be avoided.

(Example 1) An electrophotographic apparatus of an example of an electrophotographic method using the toner of the present invention is a commercially available copying machine (FP-4080, modified by Matsushita Electric Industrial Co., Ltd.). went. In this embodiment, the two-component developing method is used as the developing method, but the present invention is not limited to this, and a one-component developing method can also be used.

In the examples, the binder resins shown in (Table 1),
A toner was experimentally manufactured using the wax shown in (Table 2) and the material shown in (Table 3). The toner B3 has the same composition as the toner A1, but the external additive formulation is different.

[0172]

[Table 1]

[0173]

[Table 2]

[0174]

[Table 3]

In (Table 3), the addition amount represents parts by weight. The amount of the external additive added is 100
The value is based on parts by weight.

The softening point of the binder resin was determined by a flow tester (CFT-500) manufactured by Shimadzu Corporation to measure a sample of 1 cm ^{3 at} a temperature rising rate of 6 ° C./min and a plunger of 20 kg / cm ² . Load is applied, diameter 1mm, length 1
The nozzle of mm is pushed out. From the relationship between the amount of drop of the plunger and the temperature rise temperature characteristic,
The temperature for / 2 is the softening point.

As the weight average molecular weight of the resin, the value measured by gel permeation chromatography using several kinds of monodisperse polystyrene as standard samples is used. At a temperature of 25 ° C., tetrahydrofuran is used as a solvent at a flow rate of 1 ml / min.
10 mg of a sample solution of tetrahydrofuran is injected by a sample weight and measured. As the measurement conditions, a condition is selected in which the molecular weight distribution of the target sample is included within the range in which the logarithm of the molecular weight and the count number are linear in the calibration curve obtained from several kinds of monodisperse polystyrene standard samples. Also, HP / LP
The ratio is determined by distinguishing the HP side / LP side from a valley between a peak having a high molecular weight peak and a peak having a low molecular weight peak in the molecular weight distribution curve of the binder resin.

The melt index value indicates the weight of the binder resin flowing out from the orifice at a constant load and a constant temperature for a constant time. In the experiment, using a melt indexer,
What was flown out under a load of 150 ° C. and 2160 g for 10 minutes was taken as a melt index value, and JIS K 676 was used.
It measured based on 0. The fact that the melt index is large indicates that the resin easily flows at the temperature, and can be said to be an index of the fixability.

The glass transition temperature (Tg) was once measured with a differential scanning calorimeter (DSC-50, manufactured by Shimadzu Corporation).
D when heating up to 50 ° C and cooling at 7.5 ° C / min
It was measured by the tangent method from the SC curve.

The softening point of the wax is an index of the temperature at which the wax becomes a molten state, and is defined by JIS K 2207-6.4.
It measured based on -93.

Penetration was measured at 25 ° C. according to JIS K 2235-6.3-93 as an index showing the hardness of wax at room temperature.

The recovery rate after washing with toluene was measured as follows. 100 g of wax was put in 1000 ml of toluene at 25 ° C., stirred for 1 hour, and then the whole was filtered with a filter paper. The extraction residue on the filter paper is thoroughly dried at room temperature,
The weight before and after washing was measured and the recovery rate was calculated.

Table 4 shows the physical properties of the toners shown in Table 3.

[0184]

[Table 4]

In (Table 4), the quietness density is
It defines the fluidity of the toner, and a large value indicates that the fluidity is high. Quietness Density is measured by Hosokawa Micron's Powder Tester PT-
Type E was used.

The charge amount was measured by the blow-off method.
The measurement sample has a DBP oil absorption of 360 ml /
100g, specific surface area 800m^Two/ G, PH8 carbon
Average particle size coated with silicone resin containing black
Volume resistance 3 × 10 at 80 μm ⁸Ωcm Cu-Zn-F
e_TwoO_ThreeUse particles so that the toner concentration is 3.5%
Toner is mixed into a 100 ml polyethylene bottle.
Put it in, and stir it for 10 min at 60 rpm.
used.

For the DBP oil absorption, 20 g of a sample dried for 1 hour at 150 ° C. ± 1 ° C. was used as an absorber meter (Brave).
It is put into a mixing chamber having a spring tension of 2.68 kg / cm manufactured by Nder Co., and the limit switch is set to about 70% of the maximum torque in advance, and then the mixer is rotated. At the same time, the DBP (specific gravity 1.045 to 1.05
0 g / cm ³ ) is added at a rate of 4 ml / min. Near the end point, the torque increases rapidly and the limit switch is turned off. The DBP oil absorption per 100 g of the sample can be obtained from the amount of DBP added up to that point and the sample weight.

For PH, 100 ml of distilled water was added to a test amount of 10 g, the mixture was boiled on a hot plate for 10 minutes, cooled to room temperature, the supernatant was removed and separated, and the pH of the sludge was measured with a glass electrode PH meter. .

The volume resistance of the carrier is 2 × 1 cm.
While the electrodes of 2) were opposed to each other at a distance of 2 mm, 0.2 g of a sample carrier was introduced, a bridge was formed between the electrodes by a magnet opposed to the outside of the electrodes, and 1000 V was applied to the electrodes for measurement.

Regarding the storage stability, the toner was left to stand in an environment of 50 ° C. and 50% RH for 24 hours, and the toner cohesiveness before and after that was sensory evaluated.

The specific surface area was measured by BET1 by nitrogen adsorption.
Performed by the point method. Measuring device f manufactured by Shimadzu Corporation
This was done using a lowsorb 2300.

The volume average particle diameter of the carrier is Nikkiso Co., Ltd.
It was measured using a Microtrac manufactured by.

Copy tests were carried out using various toners to evaluate the copied images. Table 5 shows the image evaluation results and fixing properties of the toners of Table 3.

[0194]

[Table 5]

The image density was measured by a reflection densitometer (Macbeth) and evaluated. Toner fixability is based on image density of 1.
The fixed sample image of 0 was quantified by continuously outputting 5 sheets with a modified FP-4080 machine (process speed 350 mm / s) and conducting a rubbing test. The rubbing test is
Place the measurement image sample on a smooth glass plate, 70 g /
A non-woven fabric (Bencott, manufactured by Asahi Chemical Industry Co., Ltd.) to which a load of cm ² was applied was rubbed for 10 reciprocations, and the image density retention rate before and after rubbing was defined as the fixability.

When the toners A1, A2 and A3 are used,
In the initial copied image, there was no disturbance of horizontal lines or scattering of toner, and a high-density solid black image having an image density of 1.4 or more was uniformly obtained. There is no background fog in the non-image area.
The initial image quality was maintained even in the continuous printing test of 150 k sheets. However, the toner sample B1 has a low fixing rate,
The background fog, which is thought to be due to poor dispersion, increased. With toner sample B2, the storage stability was poor and photoreceptor filming occurred. Further, in toner sample B3, the toner fluidity was low, and photoconductor filming occurred.

(Embodiment 2) An electrophotographic apparatus according to an embodiment of the electrophotographic method using the toner of the present invention is a commercially available copying machine (FP-4080, Matsushita Electric Industrial Co., Ltd.) equipped with a waste toner recycling mechanism. It was carried out using the added modified machine. The developer is a carrier coated with a silicone resin and has an average particle size of 8
Cu-Zn-Fe ₂ O ₃ particles of 0 μm were used, and the toner was mixed so that the toner concentration was 3.5%, and 100 ml was added.
Put it in a polyethylene bottle, and rotate at 60 rpm for 10
The one stirred for min was used.

When the toners A1, A2 and A3 are used,
In the initial copied image, there was no disturbance of horizontal lines or scattering of toner, and a high-density solid black image having an image density of 1.4 or more was uniformly obtained. There is no background fog in the non-image area.
Even in the continuous printing test of 150 k sheets in which waste toner was recycled, stable recycling was possible and the initial image quality was maintained.

(Embodiment 3) An electrophotographic apparatus according to an embodiment of an electrophotographic method using the toner of the present invention has a roller transfer mechanism added to a commercially available copying machine (FP-4080, Matsushita Electric Industrial Co., Ltd.). It was performed using the modified machine. Developer uses the Cu-Zn-Fe ₂ O ₃ particles having an average particle size of 80μm was a silicone resin coated carrier, the toner concentration is 3.
The toner was mixed so as to be 5%, put in a 100 ml polyethylene bottle, and stirred for 10 min at a rotation speed of 60 rpm.

When the toners A1, A2 and A3 are used,
In the initial copied image, there was no disturbance of horizontal lines or scattering of toner, and a high-density solid black image having an image density of 1.4 or more was uniformly obtained. There is no background fog in the non-image area.
In the continuous printing test of 150k sheets in which the waste toner was recycled, the initial image quality was maintained without roller contamination.

(Embodiment 4) FIG. 1 schematically shows an electrophotographic apparatus of an embodiment for carrying out an electrophotographic method using the toner of the present invention.

As the developing method, a one-component developing method is used. Numeral 1 is an organic photoconductor that rotates in one direction. Polyvinyl butyral resin (Elec BL-1 manufactured by Sekisui Chemical Co., Ltd.) on a conductive support made of aluminum and τ type metal-free phthalocyanine (produced by Toyo Ink Mfg. Co., Ltd.) ), A polycarbonate resin (Z-200 manufactured by Mitsubishi Gas Chemical Co., Inc.), 1,1-bis (P-diethylaminophenyl) -4,4-diphenyl-1,3.
-A structure in which charge transport layers containing butadiene (T-405 manufactured by Anan) are sequentially laminated. The photoconductor 1 is provided with a magnet 2 coaxially fixed to the photoconductor 1, a corona charger 3 for negatively charging the photoconductor 1, and a grid electrode 4 for controlling the charging potential of the photoconductor. The signal light 5 is emitted to form a latent image.

As a developing device for developing the latent image after exposure, a toner hopper 6 for supplying the toner 7 to the surface of the photoconductor 1 and a non-magnetic electrode roller set with a gap with the photoconductor 1 are set. 8, a magnet 9 installed inside the electrode roller 8, an AC high-voltage power supply 10 for applying a voltage to the electrode roller 8, and a scraper 11 made of a polyester film for scraping off the toner on the electrode roller. The roller 8 collects excess toner adhering to the non-image portion of the photoconductor 1. Reference numeral 21 denotes a damper for smoothing the flow of the toner 7 in the toner hopper 6 and for preventing the toner 7 from being crushed by its own weight and causing clogging between the photoconductor 1 and the electrode roller 8. It is.

A magnetic field having a magnetic flux density of 600 Gs is formed on the surface of the photoconductor 1. By making the magnetic force inside the electrode roller 8 stronger, the transportability in collecting the toner is improved. The magnetic pole angle θ of the magnet 2 shown in the drawing is 1
It is set to 5 degrees. The photoreceptor 1 has a diameter of 30 mm and is rotated at a peripheral speed of 60 mm / s in the direction of the arrow in the figure.
The diameter of the electrode roller 8 is 16 mm, and the electrode roller 8 is rotated at a peripheral speed of 40 mm / s in the direction opposite to the traveling direction of the photoconductor (the direction of the arrow in the figure). The gap between the photoconductor 1 and the electrode roller 8 is 3
It is set to 00 μm.

The photoconductor 1 is connected to the corona charger 3 (applied voltage-
-50 at 4.5kV, voltage of grid 4 -500V)
The photosensitive member 1 is charged with a laser beam 5 to form an electrostatic latent image. At this time, the exposure potential of the photoconductor 1 is -9.
0V. A toner hopper 6 is provided on the surface of the photoconductor 1.
In the process of rotating in contact with the toner, the toner 7 adheres by the magnetic force of the magnet 2. Next, the photoconductor 1 passes in front of the electrode roller 8.

When the photoconductor 1 passes through the uncharged area, the electrode roller 8 is superposed with a DC voltage of 0 V by the AC high voltage power source 750 V 0-p (peak-to-peak 1.5.
kV) AC voltage (frequency 1 kHz)
When the photoconductor 1 charged to -500V and having the electrostatic latent image written thereon is passed, the electrode roller 8 is superposed with a DC voltage of -350V by the AC high voltage power source 750V0-p (peak-to-peak 1. An AC voltage (frequency 1 kHz) of 5 kV) is applied. Then, the toner adhered to the non-image portion of the charged portion of the photoconductor 1 is collected by the electrode roller 8, and a negative-positive toner image of only the image portion remains on the photoconductor 1. The toner adhered to the electrode roller 8 rotating in the direction of the arrow is scraped off by the scraper 11, returned to the toner hopper 6 again, and used for the next image formation.

The toner image thus obtained on the photosensitive member 1 is transferred onto the transfer paper by the corona transfer device 12, and thereafter,
The image is thermally fixed by a fixing device (not shown) to obtain a copied image.

Reference numeral 18 is a cleaning blade for scraping off the waste toner of the transfer residue, 19 is a cleaning box for temporarily storing the waste toner, and 23 is the waste toner.

In the examples, the binder resins shown in (Table 1),
Toners were experimentally manufactured using the waxes shown in (Table 2) and the materials shown in (Table 6).

[0210]

[Table 6]

Copying was carried out by the electrophotographic method shown in FIG. 1 using various toners, and the copied images were evaluated.

Table 7 shows the physical properties of the toners shown in Table 6.

[0213]

[Table 7]

Table 8 shows the image evaluation results and fixing properties of the toners of Table 6.

[0215]

[Table 8]

The image density was evaluated by measuring with a reflection densitometer (Macbeth). Toner fixability is based on image density of 1.
The fixed sample image of No. 0 was quantified by outputting five continuous images by the electrophotographic method (process speed 65 mm / s) shown in FIG. 1 and performing a rubbing test. The rubbing test is
Place the measurement image sample on a smooth glass plate, 70 g /
A non-woven fabric (Bencott, trade name, manufactured by Asahi Chemical Industry Co., Ltd.) to which a load of cm ² was applied was rubbed 10 times back and forth, and the image density maintenance ratio before and after rubbing was taken as the fixability.

The hot offset property was that the process speed was 32 mm / s, the fixing temperature was changed, and the occurrence of hot offset was visually observed to record the temperature. Toner A
When A4, A5, and A6 are used, there is no horizontal line disturbance or toner scattering in the initial copy image, and the image density is 1.
A solid black image having a high density of 4 or more was uniformly obtained, and an extremely high-resolution and high-quality image in which an image line of 16 lines / mm having a density of 1.4 was reproduced was obtained. There is no background fog in the non-image area. However, in toner sample B4, the fixing rate was low, and the background fog, which is considered to be caused by poor dispersion, increased. With toner sample B5, the storage stability was poor and photoreceptor filming occurred. Further, in toner sample B6, the toner fluidity was low, and photoconductor filming occurred.

(Embodiment 5) FIG. 2 schematically shows an electrophotographic apparatus which is an embodiment of an electrophotographic method using the toner of the present invention.

This is a structure in which a waste toner recycling process is added to the structure of the electrophotographic apparatus shown in FIG. 1 of the fourth embodiment.

Reference numeral 18 is a cleaning blade for scraping off the waste toner of the transfer dust, 19 is a cleaning box for temporarily storing the waste toner, and 23 is the waste toner.

Although an elastic urethane blade was used as the cleaning blade, a fur brush to which bias was applied,
Similar results are obtained with a conductive metal roller.

Reference numeral 20 denotes a transport pipe for sending the waste toner to the toner hopper 6 of the developing device, which is a process for recycling the waste toner after transfer. The method of transportation may be, but not limited to, a method using air, a method of sending in a spiral, a magnetic method, a vibration method, and the like.

When the toner A4 is used, there is no disturbance of horizontal lines and scattering of toner in the initial copy image, and a high-density solid black image having an image density of 1.4 or more is uniformly obtained.
In addition, an extremely high-resolution and high-quality image which reproduced an image of 16 lines / mm having a density of 1.4 was obtained. Continuous printing was performed on 10,000 sheets while recycling the waste toner, but there was no increase in background fog in the non-image area.

(Embodiment 6) FIG. 3 schematically shows an electrophotographic apparatus of an embodiment of an electrophotographic method using the toner of the present invention.

This is a structure in which a roller transfer mechanism is added to the structure of the electrophotographic apparatus shown in FIG. 1 of the fourth embodiment.

Reference numeral 13 denotes a transfer roller for transferring the toner image on the photoconductor onto the paper, which is set so as to come into contact with the photoconductor 1. The transfer roller is an elastic roller having a conductive elastic member around a shaft made of a conductive metal. The pressing force on the photoconductor 1 is 0 per transfer roller 13 (about 216 mm).
~ 2000g, preferably 500-1000g.
This was measured from the product of the spring coefficient of the spring for bringing the transfer roller 13 into contact with the photoreceptor 1 and the contraction amount. The contact width with the photoconductor 1 is about 0.5 to 5 mm. The rubber strength of the transfer roller 13 is 80 degrees or less by the Asker C measurement method (measurement using a block piece, not the roller shape), and preferably 30 degrees.
~ 40 degrees. In the present invention, the elastic roller 13 has a diameter of 6
A foamed conductive urethane elastomer internally added with a lithium salt having a resistance value of 10 ⁷ Ω (measured by applying electrodes of 500 V between the shaft and the surface) was used around the shaft of mm. Outer diameter of the entire transfer roller 13 is 16.4 mm
The hardness was 40 degrees in Asker C. The pressing force was 1000 g.

The present invention is not limited to this material. For the elastic body of the roller, CR rubber, NBR, Si rubber,
Examples thereof include fluororubber, and urethane foam is preferable. As a conductivity-imparting agent for imparting conductivity, a car
Bon black and lithium salts such as Li ₂ O are preferred.

Reference numeral 14 is a thrust guide made of a conductive member for introducing the transfer paper to the transfer roller 13, and reference numeral 15 is a conveyance guide in which the surface of the conductive member is covered with an insulating material. The rush guide 14 and the transport guide 15 are grounded directly or via a resistor. Reference numeral 16 is a transfer sheet, and 17 is a voltage generating power source for applying a voltage to the transfer roller 13.

When Toner A4 is used, there is no disturbance of horizontal lines or scattering of toner in the initial copy image, and a high-density solid black image with an image density of 1.4 or more is uniformly obtained.
In addition, an extremely high-resolution and high-quality image which reproduced an image of 16 lines / mm having a density of 1.4 was obtained. There was no filming on the transfer roller, and there was no increase in background fog in the non-image area.

(Embodiment 7) FIG. 5 is a sectional view of an electrophotographic apparatus according to an embodiment of the electrophotographic method of the present invention.

The operation when forming a color image will be described. 201
Is an outer casing of the color electrophotographic printer, and the right end face side in the drawing is the front face. Reference numeral 201A denotes a printer front plate, and the front plate can be freely tilted and opened as shown by a dotted line with respect to the hinge shaft 201B on the lower side with respect to the printer outer casing 201, and raised and closed as shown by a solid line. The front plate 201 is used for the operation of attaching / detaching the intermediate transfer belt unit 202 to / from the printer, and inspecting and maintaining the inside of the printer when a paper jam occurs.
This is done by tilting A to open and largely opening the inside of the printer. The attachment / detachment operation of the intermediate transfer belt unit 202 is designed to be perpendicular to the direction of the rotation axis generatrix of the photoconductor.

The construction of the intermediate transfer belt unit 202 is shown in FIG. The intermediate transfer belt unit 202 includes a transfer belt 203, a first transfer roller 204 made of a conductive elastic body, a second transfer roller 205 made of an aluminum roller, a tension roller 206 for adjusting the tension of the transfer belt, and a transfer belt in a unit housing 202a. A belt cleaner roller 207 for cleaning the toner image remaining on the upper surface, a scraper 208 for scraping the collected toner on the cleaner roller 207, and a waste toner reservoir 2 for collecting the collected toner.
09a and 209b, and a position detector 210 for detecting the position of the transfer belt is included. The intermediate transfer belt unit 202 is shown in FIG.
Can be attached to and detached from a predetermined storage portion in the printer outer casing 201 by tilting it open as shown by a dotted line.

The intermediate transfer belt 203 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 Z3 manufactured by Mitsubishi Gas Chemical Co., Inc.) is used as the insulating resin.
00) to 95 parts by addition of 5 parts of conductive carbon (for example, Ketjen black) to form a film. The surface was coated with a fluororesin. The film thickness is about 350
μm, and the resistance was about 10 ⁷ to 10 ⁸ Ω · cm.

This transfer belt is made of an endless belt-like film having a thickness of 100 μm and made of semiconductive urethane as a base material, and is subjected to a low resistance treatment so as to have a resistance of 10 ⁷ Ω · cm in the periphery. It is wound around the first transfer roller 204, the second transfer roller 205, and the tension roller 206, which are molded, and is movable in the arrow direction. Here, the peripheral length of the transfer belt is a length (62 mm) slightly longer than a half of the peripheral length of a photosensitive drum (diameter 30 mm), which will be described later, in the length (298 mm) in the longitudinal direction of A4 paper, which is the maximum paper size. Is set to 360 mm.

When the intermediate transfer belt unit 202 is mounted on the printer body, the first transfer roller 204 is
The photosensitive member 211 (shown in FIG. 6) is pressed against the photosensitive member 211 via the intermediate transfer belt 203 with a force of about 1.0 kg, and the second transfer roller 205 is pressed against the first transfer roller 204 via the intermediate transfer belt 203. Third transfer roller 21 having the same configuration as
2 (shown in FIG. 6). The third transfer roller is configured to be driven and rotated by the intermediate transfer belt 203.

The cleaner roller 207 is a roller of a belt cleaner section for cleaning the intermediate transfer belt 203. This is a configuration in which an AC voltage that electrostatically attracts 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.

Returning again to FIG. Black in the center of the printer,
Four sets of fan-shaped image forming units 217Bk, 217Y, 217M and 21 for cyan, magenta and yellow
7C constitutes the image forming unit group 218, and is arranged in an annular shape as shown in the drawing. Each image forming unit is attachable to and detachable from a predetermined position of the image forming unit group 218 by opening the printer upper surface plate 201C of FIG. 5 around the hinge shaft 201D. The image forming unit 217 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). Integrate mechanically and electrically.

Image forming unit 2 arranged in an annular shape
17Bk, 217C, 217M, and 217Y are supported by a support (not shown), and are driven by a moving motor 219, which is a moving means as a whole, and are rotatable about a cylindrical shaft 220 that is fixed and does not rotate. Is configured. Each image forming unit has a second transfer roller 204 that sequentially supports the intermediate transfer belt 203 by rotational movement.
Can be located at an image forming position 221 opposite to.
The image forming position 221 is also an exposure position by the signal light 222.

Since each image forming unit is made of the same constituent member except the developer contained therein, the image forming unit 217Bk for black will be described and the other colors will be omitted for simplification of description. For each color,
The same portions are denoted by the same reference numerals, and when it is necessary to distinguish the configurations of the respective colors, the reference numerals are assigned with the letters indicating the respective colors.

Two-component developer was used for the development, and Cu--Zn--Fe ₂ O ₃ particles coated with silicone resin were used as the carrier.

Returning to FIG. 5, the description will be continued. Reference numeral 235 denotes a laser beam scanner section arranged in the lower side of the printer outer casing 1 and includes a semiconductor laser, a scanner motor 235a, a polygon mirror 235b, a lens system 235c, and the like. The pixel laser signal light 222 corresponding to the time series electric pixel signal of the image information from the scanner unit 235 passes through the optical path window 236 formed between the image forming units 217Bk and 217Y of FIG. Fixed mirror 238 in shaft 220 through window 237 opened in
To the image forming unit 2 from the exposure window 225 of the image forming unit 217Bk located at the image forming position 221.
The developer reservoir 226 and the cleaner 234, which enter the 17Bk substantially horizontally and are vertically arranged in the image forming unit,
The light enters the exposure portion on the left side surface of the photoconductor drum 211 through the passage between and and is scanned and exposed in the generatrix direction.

Here, the optical path from the optical path window 236 to the mirror 238 is the image forming units 217Bk and 217Y on both sides.
Since the space between the units of and is used, the image forming unit group 218 has almost no wasted space. Further, since the mirror 238 is provided in the central portion of the image forming unit group 218, it can be configured by a single fixed mirror, and it has a simple configuration and easy alignment.

Reference numeral 212 denotes a third transfer roller disposed inside the printer front plate 201A and above the feeding roller 239. The nip portion where the intermediate transfer belt 203 and the third transfer roller 212 are in pressure contact with each other is a printer. A paper feed path is formed so that the paper is fed by a paper feed roller 239 provided below the front plate 201A.

Reference numeral 240 denotes a paper feeding cassette provided on the lower side of the printer front plate 201A so as to project outward, and a plurality of papers S can be set at the same time. 241a and 241b are paper conveyance timing rollers, 242a and 242b are fixing roller pairs provided on the upper inside of the printer, 243 is a paper guide plate provided between the third transfer roller 212 and fixing roller pairs 242a and 242b, 244a and 244b. Is a pair of fixing rollers 24
A pair of paper discharge rollers arranged on the paper exit side of 2a and 242b,
A fixing oil reservoir 245 stores a silicone oil 246 to be supplied to the fixing roller 242a and an oil supply roller 247 applies the silicone oil 246 to the fixing roller 242a. The above is the description of the main configuration of the electrophotographic apparatus of the present invention.

In the electrophotographic apparatus of the present invention, each image forming unit and the intermediate transfer belt unit are provided with a waste toner reservoir. When the toner of the present invention is used, since the transfer rate is high, almost no waste toner is generated, so that the volume can be made very small.

Initially, the image forming unit group 218 is in the position shown in FIG. 5, and the black image forming unit 217Bk is in the image forming position 221 as shown. At this time, the photoconductor 211
Is the first transfer roller 204 via the intermediate transfer belt 203.
Are in contact with each other.

By the image forming process, the laser exposure device 235
As a result, black signal light is input to the image forming unit 217Bk, and image formation is performed using black toner. At this time, the image forming speed of the image forming unit 217Bk (60 mm / s, which is equal to the peripheral speed of the photoconductor) and the moving speed of the intermediate transfer belt 203 are set to be the same.
The black toner image is transferred to the intermediate transfer belt 203 by the action of the transfer roller 204. At this time, the first transfer roller is +
A DC voltage of 1 kV was applied. Immediately after the transfer of all black toner images, the image forming units 217Bk, 21
The positions 7C, 217M, and 217Y are driven as a whole by the moving motor 219 as the image forming unit group 218 to rotate in the direction of the arrow in FIG. 5 and rotate exactly 90 degrees to reach the image forming position 221 of the image forming unit 217C. Stop at.
During this time, the toner hopper 2 other than the photoconductor of the image forming unit
26 and the cleaner 234 are located inside the rotation arc of the tip of the photoconductor 211, the intermediate transfer belt 20
3 does not contact the image forming unit.

The image forming unit 217C moves to the image forming position 22.
After the arrival at 1, the laser exposure device 235 inputs the signal light to the image forming unit 217C by the cyan signal, as in the previous case, and the cyan toner image is formed and transferred. By this time, the intermediate transfer belt 203 makes one rotation, and the writing timing of the cyan signal light is controlled so that the next cyan toner image is positionally aligned with the previously transferred black toner image. During this time, the third transfer roller 212 and the cleaner roller 207 are slightly apart from the intermediate transfer belt 203, and are configured 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 toner images of four colors were positionally superposed on each other on the intermediate transfer belt 203 to form a color image. After the final transfer of the yellow toner image, the four color toner images were collectively transferred onto the paper fed from the paper feed cassette 240 by the action of the third transfer roller 212 at the same timing. At this time, the second transfer roller 205 was grounded, and a DC voltage of +1.5 kV was applied to the third transfer roller 212.
The toner image transferred to the paper is the fixing roller pair 242a.2.
It was fixed by 42b. The paper is then ejected roller pair 2
It was discharged to the outside of the device via 44a and 244b. The untransferred toner remaining on the intermediate transfer belt 203 is cleaned by the action of the cleaner roller 207 to prepare for the next image formation.

Next, the operation in the single color mode will be described. In the single color mode, the image forming unit of a predetermined color first moves to the image forming position. Next, as in the previous case, image formation of a predetermined color and transfer to the intermediate transfer belt 203 are performed, and this time after the transfer, the process is continued as it is, and the next third transfer roller 212 transfers the paper to the paper sent from the paper feed cassette 240. Transferred and fixed as it was.

In the above embodiments, the specific structure of the image forming unit is used. However, even in the case of the image forming unit having the structure using the conventional developing method,
The essence and effects of the present invention remain unchanged.

Examples of the yellow colorant of the toner include a benzidine yellow pigment, phorone yellow, an acetoacetic anilide insoluble azo pigment and a monoazo dye.

Examples of magenta colorants include 2,9-dimethylquinacridone, naphthol-based insoluble azo pigments, anthraquinone-based dyes, and nafrole-based insoluble azo pigments.

Table 9 shows the composition of the color toner used in this example.

[0255]

[Table 9]

As the binder resin, the resin r-2 shown in (Table 1) was used. 20 parts by weight of a polyester resin having an acid value of 20 was added as a charge control agent. The acid value is preferably 5-40.
The addition amount is preferably 5 to 45 parts by weight with respect to 100 parts by weight of the binder resin.

The toner charge amount is −15 to − for each toner.
It was 18 μC / g. The value of (General Formula 1) was 0.35 to 0.37 for each toner.

A copying test was conducted with the toner of the present invention using the electrophotographic apparatus shown in FIG. As a result, an extremely high-resolution and high-quality image is obtained, in which horizontal lines are not disturbed, toner is not scattered, hollow characters are not present, and a solid black image is evenly reproduced and 16 lines / mm with a density of 1.4 are reproduced. Was given. A high-density image having an image density of 1.4 or more was obtained. No background fog has occurred in the non-image area.

In the long-term durability test of 10,000 sheets,
It shows stable characteristics with little change in fluidity and image density. Also in the transfer, the void was at a level where there was no practical problem, and the transfer efficiency was 90%. The occurrence of toner filming on the photoconductor and the intermediate transfer belt was at a practically acceptable level.

[0260]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, a toner containing a wax whose physical properties are specified and whose external processing conditions are specified in the manufacturing process, an image carrier which contains a fixed magnet and moves, and an image A developing process including an electrode roller having an electrode roller having a magnet inside, which is installed at a position having a predetermined gap from the surface of the carrier, a transfer process using a conductive elastic roller, a cleaning process, and waste toner. By combining it with an electrophotographic method that includes a step of recycling the intermediate transfer member and an electrophotographic method that uses an intermediate transfer member, excellent fixability, developability, and transfer efficiency can be obtained. It is possible to prevent the filming of the toner on the transfer medium.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an electrophotographic apparatus of an embodiment of an electrophotographic method in which the toner of the present invention is used.

FIG. 2 is a schematic configuration diagram of an electrophotographic apparatus of an embodiment of an electrophotographic method in which the toner of the present invention is used.

FIG. 3 is a schematic configuration diagram of an electrophotographic apparatus of an embodiment of an electrophotographic method in which the toner of the present invention is used.

FIG. 4 is a schematic configuration diagram showing a configuration of a toner image transfer device.

FIG. 5 is a sectional view of an electrophotographic apparatus according to an embodiment of an electrophotographic method in which the toner of the present invention is used.

FIG. 6 is a configuration diagram of an intermediate transfer belt unit of the present invention.

FIG. 7 is a block diagram of a conventional color electrophotographic apparatus.

[Explanation of symbols]

1 photoconductor drum 2 fixed magnet 3 contained in the photoconductor 3 corona charger 4 grid electrode 6 toner hopper 7 toner 8 electrode roller 9 magnet installed inside the electrode roller 11 scraper 12 transfer charger 13 transfer roller 14 plunge guide 15 Conveyance Guide 16 Transfer Paper 17 Transfer Roller Power Supply 18 Cleaning Blade 19 Cleaning Box 20 Transport Pipe 21 Damper 23 Waste Toner 32 Developing Sleeve 33 Layer Control Blade 34 Power Supply 35 Corona Transfer Device 100 Transfer Roller 101 Power Supply 102 Photosensitive Member 103 Transfer Paper 104 Toner 202 Intermediate transfer belt unit 203 Intermediate transfer belt 204 First transfer roller 205 Second transfer roller 206 Tension roller 211 Photoconductor 212 Third transfer roller 215 Spring 216 Roller 217Bk, 217C, 217M, 217Y Image forming unit 218 Image forming unit group 221 Image forming position 222 Laser signal light 235 Laser exposure device 238 Mirror

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G03G 9/10 352 21/00 326 (72) Inventor Masatoshi Maeda 1006 Kadoma, Kadoma, Osaka Prefecture Matsushita Denki Sangyo Co., Ltd.

Claims (10)

[Claims] 1. A toner comprising a toner base composed of at least a binder resin, colorant particles and a wax, and an external additive, wherein the binder resin comprises at least polyethylene. The wax is contained in an amount of 0.5 to 10 parts by weight based on 100 parts by weight of the binder resin, and the wax is produced by a thermal decomposition method and has a recovery of 95% or more when washed with toluene at 25 ° C. for 1 hour. The softening point of the wax is 80 to 140 ° C., the penetration at 25 ° C. is 8 or less, the specific surface area St (m ² / g) of the toner, and the specific surface area Sb (m of the toner base). ² / g), the specific surface area Sa (m ² / g) of the external additive, and the added amount W (wt%) of the external additive.
The toner is characterized by 0.3 ≦ (St-Sb) / (Sa * W / 100) ≦ 0.7. 2. A developing step in which an electrostatic latent image on a photoconductor is visualized by toner, a transfer step in which the toner visualized in the photoconductor is transferred to a transfer paper, and the transfer step An electronic device having at least a cleaning step of removing the toner partially remaining on the photoconductor from the photoconductor, and a waste toner recycling step of returning the waste toner removed in the cleaning step to the developing step for reuse. A toner used in a photographic method, wherein the toner is composed of at least a binder resin, a toner base composed of colorant particles, and a wax, and an external additive. 0.5 to 10 parts by weight of the wax composed of at least polyethylene per 100 parts by weight of the binder resin, and the wax is prepared by a thermal decomposition method. The recovery rate after washing with toluene at 25 ° C. for 1 hour is 95% or more, the softening point of the wax is 80 to 140 ° C., the penetration at 25 ° C. is 8 or less, and the toner is Specific surface area St (m ² / g), specific surface area Sb (m ² / g) of the toner base, specific surface area Sa (m ² / g) of the external additive, and additive amount W (wt%) of the external additive )
The toner is characterized by 0.3 ≦ (St-Sb) / (Sa * W / 100) ≦ 0.7. 3. A step of transferring a visible image toner on the photosensitive member by a transfer bias voltage applied to the conductive elastic roller in the transferring step, the conductive elastic roller being in contact with the photosensitive member. 3. The toner according to claim 2, which is used in the electrophotographic method. 4. The developing step is constituted by a two-component developing method comprising a toner and a carrier, and the surface has at least a DBP oil absorption of 60 to 400 ml / 10.
0 g, specific surface area 100-1300 m ² / g, PH 8.5
It has a structure provided with a coating layer made of a fluorine resin or a silicone resin containing the following carbon black, and has a volume average particle diameter of 60 to 120 μm and a volume resistance of 1 × 10 ⁵ to
4. The toner according to claim 2, wherein the toner is used in an electrophotographic method using the carrier having a frictional charge amount of 1 × 10 ¹⁰ Ωcm and 6-20 μC / g with the toner. 5. An electrostatic latent image is formed on a moving photoconductor containing a fixed magnet, and then toner is magnetically attracted to the surface of the photoconductor located in a toner hopper, and the toner is attracted to the surface of the photoconductor. The toner is carried, the photoconductor is moved, and it is made to face a toner recovery electrode roller having a magnet inside at a position having a predetermined gap with the surface of the photoconductor to leave the toner on the image portion of the photoconductor. A developing step in which the toner in the non-image portion is collected by the toner collecting electrode roller; a transfer step in which the toner that is visualized on the photoconductor is transferred to a transfer sheet by electrostatic force; A toner used in an electrophotographic method having at least a cleaning step for removing the toner remaining on the photoconductor from the photoconductor, wherein the toner is at least a binder resin, colorant particles, and a wax. A toner comprising a toner matrix composed of: and an external additive, wherein the wax composed of at least polyethylene is contained in the binder resin in an amount of 0.5 to 100 parts by weight per 100 parts by weight of the binder resin. 10 parts by weight, and the wax was prepared by a thermal decomposition method, the recovery rate when washed with toluene at 25 ° C. for 1 hour was 95% or more, and the softening point of the wax was 80 to 140 ° C. and 25 ° C. The specific surface area St (m ² / g) of the toner, the specific surface area Sb (m ² / g) of the toner base, and the specific surface area Sa (m ^{2 of the} external additive) / G), the amount of addition of the external additive W (wt%)
The toner is characterized by 0.3 ≦ (St-Sb) / (Sa * W / 100) ≦ 0.7. 6. An electrostatic latent image is formed on a moving photoconductor containing a fixed magnet, and then the toner is magnetically attracted to the surface of the photoconductor located in the toner hopper, and the toner is magnetically attracted to the surface of the photoconductor. The toner is carried, the photoconductor is moved, and is opposed to a toner collecting electrode roller having a magnet inside at a position having a predetermined gap with the surface of the photoconductor to leave the toner on the image portion of the photoconductor. A developing step in which the toner in the non-image portion is collected by the toner collecting electrode roller; a transfer step in which the toner that is visualized on the photoconductor is transferred to a transfer sheet by electrostatic force; At least a cleaning step of removing the toner remaining on the photoconductor from the photoconductor, and a waste toner recycling step of returning the waste toner removed in the cleaning step to the developing step for reuse. A toner for use in an electrophotographic method, comprising: a toner base comprising at least a binder resin, colorant particles, and a wax; and an external additive, The binder resin contains at least 0.5 to 10 parts by weight of the wax composed of polyethylene per 100 parts by weight of the binder resin, and the wax is prepared by a thermal decomposition method, and the wax is prepared at 25 ° C. for 1 hour. The recovery rate after washing is 95% or more, the softening point of the wax is 80 to 140 ° C., the penetration at 25 ° C. is 8 or less, and the specific surface area St (m ² / g) of the toner is , Specific surface area Sb (m ² / g) of the toner base, specific surface area Sa (m ² / g) of the external additive, and additive amount W (wt%) of the external additive
The toner is characterized by 0.3 ≦ (St-Sb) / (Sa * W / 100) ≦ 0.7. 7. A step of transferring a visible image toner on the photosensitive member by a transfer bias voltage applied to the conductive elastic roller in the transferring step, the conductive elastic roller being in contact with the photosensitive member. 7. The toner according to claim 5, wherein the toner is used in the electrophotographic method. 8. A developing step of visualizing an electrostatic latent image formed on an image carrier with toner, and a step of primary transfer of the toner to an endless intermediate transfer body in contact with the image carrier. And a step of operating the primary transfer step a plurality of times to form a transfer toner overlapping image, and collectively transferring the transfer toner overlapping image formed on the intermediate transfer member to an image receiving sheet conveyed from a sheet feeding side. And a secondary transfer step for use in an electrophotographic method, wherein the toner comprises at least a toner base composed of a binder resin, colorant particles, and a wax, and an external additive. The binder resin contains 0.5 to 10 parts by weight of the wax composed of at least polyethylene per 100 parts by weight of the binder resin, and the wax is formed by a thermal decomposition method. Create The recovery rate after washing with toluene at 25 ° C. for 1 hour is 95% or more, the softening point of the wax is 80 to 140 ° C., the penetration at 25 ° C. is 8 or less, and the toner is Specific surface area St (m ² / g), specific surface area Sb (m ² / g) of the toner base, specific surface area Sa (m ² / g) of the external additive, and additive amount W (wt%) of the external additive )
The toner is characterized by 0.3 ≦ (St-Sb) / (Sa * W / 100) ≦ 0.7. 9. The toner according to claim 8, wherein the intermediate transfer member is used in an electrophotographic method using a polycarbonate containing carbon black as a basic component. 10. The toner according to claim 8, which is used in an electrophotographic method which is an intermediate transfer member having a surface treated with a fluororesin.