JP2002214822A - Toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide toner having high toner OHP translucency, where the initial image definition can be maintained over a long period of time, toner filming to a photosensitive body and an intermediate transfer body can be prevented and high image quality at high density low surface fogging and high color reproducibility are realized. SOLUTION: In the device, it is constituted, so that the toner where the dispersed shape of wax inside the binding resin of the toner is controlled to be in a specific state is utilized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copying machine, a color copying machine, a printer, a color printer, a facsimile, and a toner used in a color facsimile.

[0002]

2. Description of the Related Art In an electrophotographic copying machine or printer, printing is performed by the following process. First, a photoconductor (hereinafter, referred to as a photoconductor) is charged for image formation. As the charging method, a conventional corona charger is used. In recent years, a contact type charging method in which a conductive roller is directly pressed against a photosensitive member with the aim of reducing the amount of generated ozone is used. Means for uniformly charging the surface have been put to practical use. After charging the photoreceptor, in the case of a copying machine, light is radiated to a copy original and reflected light is radiated to the photoreceptor through a lens system. In the case of a printer, an image signal is sent to a light emitting diode or a laser diode as an exposure light source, and a latent image is formed on a photoconductor by turning on and off light. When a latent image (high or low surface potential) is formed on the photoconductor, the photoconductor is visualized by a toner (having a diameter of about 5 μm to 15 μm), which is a pre-charged colored powder. The toner adheres to the surface of the photoconductor in accordance with the level of the surface potential of the photoconductor, and is then electrically transferred to copy paper. That is, the toner is charged positively or negatively in advance, and is applied with a charge having a polarity opposite to that of the toner from the back surface of the copy sheet and is electrically sucked. 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 of the toner on the photoreceptor is transferred to the copy sheet, but part of the toner remains on the photoreceptor. This residual toner is scraped off by a cleaning blade or the like in the cleaning unit and becomes waste toner. Conventionally, in an electrophotographic method, waste toner is discarded without being reused. Careless disposal should also be avoided from an environmental protection point of view, and reuse of waste toner is an important issue.

In a color copying machine, a photoreceptor is charged by corona discharge using a charging charger, and then a latent image of each color is irradiated as an optical signal on the photoreceptor to form an electrostatic latent image, and a first color, for example, yellow. The latent image is developed by developing with toner.

[0004] Thereafter, the toner is charged to the photoreceptor with a polarity opposite to that of the yellow toner, the transfer material is brought into contact with the photoreceptor, and the yellow toner image formed on the photoreceptor is transferred. The photoreceptor is cleaned after removing the toner remaining at the time of transfer, and is then discharged, thereby completing the development and transfer of the first color toner.

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

In this color image forming method, a toner image of each color is sequentially formed on a single photoreceptor, and a transfer material wound around a transfer drum is rotated to repeatedly face the photoreceptor. A transfer drum system in which toner images of each color are transferred in a superimposed manner, and a plurality of image forming units are arranged side by side, and each toner image of each color is sequentially passed through a transfer material conveyed by a belt through each image forming unit. A continuous superimposition method in which a color image is transferred and superimposed is generally used. A color image forming apparatus disclosed in Japanese Patent Application Laid-Open No. 1-252982 is one using the transfer drum method.

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

Further, as another method of forming a color image by superimposing toner images of different colors on a transfer material, one method is to superimpose toner images of respective colors sequentially formed on a photosensitive member on an intermediate transfer material, Japanese Patent Application Laid-Open No. H2-212867 discloses a method for collectively transferring the toner images on the intermediate transfer material to transfer paper.

As a fixing method used for permanently fixing the toner transferred to the copy sheet on the sheet, a hot roll method, a pressure roll method, a flash fixing method, a method using a chemical, and the like 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.

In the case of performing the above-described color printing, it is necessary to satisfy required characteristics unique to color from the viewpoint of fixability. Since several types of toner layers are superimposed on a color image, it is necessary to completely melt the toner and smooth the surface in terms of color development, color reproducibility or gloss, and OHP translucency. However, when the toner is excessively melted, the toner adheres to the surface of the heat roll and shifts to a transfer body such as paper which is conveyed later, that is, a so-called hot offset phenomenon occurs. To prevent this hot offset phenomenon,
Use a hot roll whose surface is coated with a material such as silicone rubber or fluororesin that has good releasability for the melted toner, apply a liquid with good releasability such as silicone oil to the surface of the hot roll, or 2. Description of the Related Art A release component such as low molecular weight polyethylene or low molecular weight polypropylene is contained in a toner. However, in these methods, the mechanism for applying oil is complicated and the size of the apparatus cannot be avoided, the oil must be replenished at regular intervals, and oil adheres to the surface of the transfer body such as paper. And the like. For this reason, it is required to reduce oil consumption as much as possible.

As is well known, toners for electrostatic charge development used in these developing methods generally include a binder resin component, a colorant comprising a pigment or dye, a plasticizer, a charge control agent,
Further, it is composed of an internal additive such as magnetic particles and wax, and an external additive as required. As the binder resin component, a natural or synthetic resin is used alone or in a suitable mixture. Then, the binder resin component and the additive component are premixed at an appropriate ratio, heat-kneaded by hot melting, then finely pulverized, and if necessary, finely classified, and an external additive is externally added to obtain a toner. Can be

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

[0013]

In recent years, from the viewpoint of protection of the global environment, the necessity of a low-temperature fixing method for reducing the amount of generated ozone and suppressing the power consumption of fixing has been called out. The toner material is also compatible with the roller transfer method that generates less ozone,
Improvements are being made in response to low-temperature fixing. Further, a high-performance toner satisfying these requirements is an important issue from the viewpoint of environmental protection.

In the fixing step, the fixing strength, which is the adhesive force of the toner on the paper, and the offset resistance for preventing the toner from adhering to the heat roller are the controlling factors. The toner melts and penetrates into the fibers of the paper by heat or pressure from the fixing roller to obtain fixing strength. Conventionally, in order to improve the fixing characteristics, the binder resin has been improved or a release agent has been added to increase the fixing strength of fixing to paper and prevent the offset phenomenon that toner adheres to the fixing roller. are doing.

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

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

For a resin composition in which a high molecular weight component and a low molecular weight component are blended or copolymerized, a release agent such as a low melting point wax, for example, polyethylene, polypropylene wax, ester wax, hydrocarbon wax, etc. Is added for the purpose of improving the releasability from the heat roller at the time of fixing and increasing the offset resistance. However, it is difficult for these release agents to improve the dispersibility in the binder resin, the reverse polarity toner is easily generated due to poor dispersion, and fogging to the non-image area occurs. In addition, it lowers the fluidity of the toner and affects the charging characteristics.
A phenomenon such as so-called toner filming or toner spent that sticks to and contaminates the carrier occurs. Further, depending on the dispersion state, in the case of a color toner, the color reproducibility of a color image is reduced, and the transparency of OHP is reduced. Dispersion is particularly difficult when a polyester resin is used as the binder resin.

Japanese Patent Application Laid-Open No. 10-161338 discloses a configuration in which a release agent component is dispersed in a granular form of 0.1 μm or less. This configuration is intended to improve the dispersibility of the release agent component in the binder resin.

In the case where a toner having a structure that enhances the gloss and translucency of a color image using a conventional low melting point release agent such as polypropylene or polyethylene and a low softening resin is used, a developing roller for development is used. The amount of mold release agent added due to the occurrence of vertical streaks on the surface, a decrease in the homogeneity of the image during development, poor cleaning or filming of the intermediate transfer body, and poor scraping of the cleaning roller of the intermediate transfer body Is reduced, the effect of the releasability is reduced, the non-offset region is narrowed, and it is difficult to achieve both.

That is, in order to realize high image quality and long life, it is not sufficient to simply disperse the wax component. As described above, in order to exhibit high releasability, the wax component is required to have a large dispersed shape and to quickly exude from the binder resin. However, in the case of such a dispersion state, in the case of two-component development, which is referred to as filming, a photosensitive member or a developing roller, adhesion or fixation to a carrier occurs, and image quality is significantly reduced. In the case of a color image, the saturation of the image and the OHP translucency are also reduced. In order to achieve a high mold release effect, development stability, and image quality at a high level, it is necessary to realize a highly controlled wax dispersion state.

Further, a contact type one-component developing device having a supply roller of urethane resin or the like for supplying toner to the development roller by using an elastic blade for regulating a toner layer in contact with a development roller of silicone resin or urethane resin. In the scheme,
The use of the toner to which the above-mentioned low-melting-point release agent is added gradually causes vertical streaks on the developing roller after the use of several thousand sheets, causing image defects such as white spots and black streaks. This is considered to be caused by damage to the developing roller due to poor dispersion of the release agent, fusion to the blade, and aggregation due to friction between the supply roller and the developing roller.

Short-length paper such as a postcard is conveyed by the frictional force with the photosensitive drum. However, in the case of a photoreceptor in which filming has occurred, the conveying force is reduced, resulting in poor postcard passing.

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

Further, the intermediate transfer system does not require a complicated optical system, can be used for a rigid paper such as a postcard or thick paper, and is flexible when an intermediate transfer belt is used. As compared with the transfer method, there is an advantage that the size of the apparatus itself can be reduced. Ideally, all of the toner is transferred at the time of transfer, but some transfer residue occurs. The so-called transfer efficiency is not 100%, but is generally about 75 to 90%. The transfer residual toner is scraped off by a cleaning blade or the like in a photoconductor cleaning process, and becomes waste toner.

In the configuration using the intermediate transfer member, the toner undergoes at least two or more transfer steps from the photosensitive member to the intermediate transfer member, and further from the intermediate transfer member to the image receiving paper. For example, in a copying machine having a transfer efficiency of 85%, a transfer efficiency of 72%
Down to. Further, in the case of a transfer efficiency of 75% in one transfer, 56% or about half of the toner becomes waste toner, so that the cost of the toner is increased and the volume of the waste toner box must be increased. In this case, the size of the device cannot be reduced. The decrease in transfer efficiency is considered to be due to background fogging or transfer omission due to reverse polarity due to poor dispersion of the release agent.

In the case of color development, toner images of four colors are superimposed on the intermediate transfer member, so that the toner layer becomes thick, and a pressure difference between a toner layer having no toner layer and a thin layer is likely to occur. For this reason, the "hollow-out" phenomenon in which a part of the image is not transferred and a hole is formed due to the aggregation effect of the toner is likely to occur.
Furthermore, if a material having a high toner releasing effect is used for the intermediate transfer member in order to surely perform cleaning when the image receiving paper is jammed, hollow holes will be noticeable and the image quality will be significantly reduced. Furthermore, edge development is performed for characters and lines, and the amount of toner is increased, and toner is aggregated by pressurization, resulting in frequent occurrence of voids. This phenomenon is particularly aggravated in a high-humidity and high-temperature environment.

It is necessary to clean and remove the toner remaining on the transfer material during the secondary transfer without being transferred, and a rubber blade, a bias-applied roller, a fur brush, or the like is used. At this time, the toner to which the releasing agent having a low melting point is added causes filming on the intermediate transfer member. Further, when the toner removed by the cleaning roller is scraped from the roller by a metal plate, the toner is fused to the metal plate, and a scraping defect occurs. In particular, by using a low-melting sharp melt resin to express glossiness and high translucency of color images,
Filming and scraping defects are more likely to occur.

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

It is important to realize a cleaner-less process without a cleaning step in order to reduce the size of equipment and save resources. After transferring the visualized toner of the electrostatic latent image formed on the photoreceptor to a transfer material by a transfer unit, the toner remaining on the photoreceptor is usually collected by cleaning to become waste toner. At this time, the cleaner-less process performs the next charging, exposing, and developing processes without a cleaning process step. First, realization of high transferability is indispensable in transfer, and sphering treatment of toner and transferability improvement by polymerization toner are performed. However, it is difficult to make the transfer efficiency 100%, and a certain amount of toner remains on the photoconductor. In the next developing process, no image problem occurs if the remaining toner in the non-image area is returned to the development. Therefore, it is an important point to collect the toner remaining in the non-image area by development.
Particularly, in a toner to which a low-melting-point release agent such as wax is added to satisfy non-offset properties at the time of fixing, the wax exposed on the surface tends to decrease the fluidity, and the transferability is not good. In the process, since it is difficult to collect by development, the memory of the image pattern before the non-image portion remains.

In the fixing process, it is necessary to mix and fuse color toners in a color image. At this time, if the toner does not melt properly, light is scattered on the surface or inside of the toner image, and the original color tone of the toner dye is impaired. descend. Therefore, it is a necessary condition that the toner has a perfect melting property and has a light-transmitting property so as not to hinder the color tone. In particular, the need for optical transparency on OHP paper is increasing due to an increase in presentation opportunities in color.

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

A belt fixing system having a medium heating section and a toner fusing / fixing section separate from each other has been used for the purpose of reducing the apparatus's flexibility and size and warming up. Therefore, the size of the apparatus can be reduced by reducing the diameter of the fixing roller.
In addition, since the curvature of the paper discharge section is increased, the paper is hardly wound around the belt. Warm-up is reduced due to the low heat capacity of the belt. However, when the toner adds a certain amount of high molecular weight component to prevent high temperature offset and has a certain elastic element, the paper on which the thin vertical line pattern of the toner is drawn when separated from the belt with large curvature The tip offset that the part takes to the belt may occur. Further, if a silicone material or a fluorine material having a strong negative charge is used for the belt, an image disorder in which an unfixed toner image repulses the belt electrostatically before entering the fixing unit is likely to occur. In particular, in a configuration in which the release oil is not applied, the influence of the charging property is likely to occur. Further, in the case of a toner to which a release agent is added for the purpose of improving the offset property, the belt is easily damaged depending on the state of dispersion, which causes vertical streaks of a fixed image.

In view of the above problems, an object of the present invention is to provide a toner having a uniform charge distribution and stabilizing an image for a long period of time.

Even when used in the one-component developing method, no vertical streaks are formed on the developing roller, heat fusion or aggregation of the toner does not occur, and even if a high-performance binder resin is used, the resin characteristics are deteriorated. An object of the present invention is to provide a toner capable of improving the dispersibility of an additive without causing the toner to maintain stable developability such as image uniformity and reproducibility.

In addition, the electrophotographic method using a conductive elastic roller or an intermediate transfer member can prevent dropout or scattering during transfer, achieve high transfer efficiency, and avoid filming on the intermediate transfer member. It is another object of the present invention to provide a toner capable of preventing fusion to a cleaning roller.

In the cleanerless process, high transfer efficiency can be obtained, the charge amount and fluidity do not decrease, no memory is generated in development, the cleanerless process can be performed, and prevention of global environmental pollution and reuse of resources are achieved. It is intended to provide a toner that enables it.

Another object of the present invention is to provide a full-color electrophotographic toner which exhibits high translucency and gloss by oilless fixing without applying oil. Filming on developing rollers, doctor blades, and intermediate transfer bodies can be avoided even with color toners using low-melting sharp-melt resins. An object of the present invention is to provide a toner that can prevent filming of a body or the like.

In the fixing process using a belt and in the belt fixing using a roller having a large curvature with a low fixing pressure and a long fixing nip, the non-wrapping property of the paper on the belt is good. An object of the present invention is to provide a toner which can prevent chipping of an image front end portion caused when a belt and paper are separated due to a large curvature, and can achieve both development and transfer properties.

It is another object of the present invention to provide a toner which does not satisfy these individual characteristics alone but can satisfy functions as a whole.

[0040]

In order to solve the above-mentioned problems, the toner of the present invention has the following constitution.

The toner comprises at least a binder resin, a wax and a colorant, and the wax is dispersed in the binder resin in a matrix in a linear or rod form.

The toner of the present invention comprises at least a binder resin, a wax and a colorant. The wax is dispersed in the binder resin in a linear or rod shape, and the arrangement of adjacent waxes is maintained in a parallel state. The toner is characterized in that:

The ratio DL / DS between the major axis diameter DL (m) and the minor axis diameter DS (m) of each wax dispersed in the binder resin.
Is the ratio of 1.0 ≦ DL / DS ≦ 2.0 to the total number of waxes, but Q1 is 2.0 <DL / DS ≦
Q2, 5.0 <DL / DS ≦
Q3, 10.0 <DL / D
Assuming that the ratio of S is Q4, the following equation (Equation 2)
The toner is characterized in that:

[0044]

(Equation 2)

Further, the toner of the present invention is characterized in that the minor axis diameter DS of the wax in the binder resin is 5 × 10 ^{−8 to} 3 × 10 ⁻⁷ (m).

Further, in the toner of the present invention, when the volume average particle diameter of the toner is DT (m), the major axis diameter DL (m) of the wax in the binder resin is such that DT / DL> 4. It is a characteristic toner.

Further, in the toner of the present invention, the wax has an acid value of 30 to 60 mg KOH / g, a melting point of 90 to 120 ° C.,
A toner characterized by being a hydrocarbon wax having an ester bond or an amide bond and having a penetration at 5 ° C. of 2 or less.

Further, the toner of the present invention is characterized in that the ester bond of the hydrocarbon wax is obtained by the reaction of a long-chain alkyl alcohol having 5 to 62 carbon atoms, an unsaturated polycarboxylic acid or an anhydride thereof. Toner.

Further, in the toner of the present invention, the wax is at least one of carnauba wax, candelilla wax, hydrogenated jojoba oil, rice wax, hydrogenated lanolin, medofoam oil, beeswax, ceresin wax or a derivative thereof. The toner is characterized by comprising two or more types.

Further, the toner of the present invention is characterized in that the volume average particle diameter of the toner is 4 to 9 × 10 ⁻⁶ (m).

Further, in the toner of the present invention, the binder resin has a weight average molecular weight Mwf of 10,000 to 40, and a weight average molecular weight Mw.
If the ratio Mwf / Mnf between f and the number average molecular weight Mnf is Wmf, Wmf is 3 to 100, and if the ratio Mzf / Mnf between the Z average molecular weight Mzf and the number average molecular weight Mnf is Wzf, Wzf is 10 to 2000, A toner using a polyester resin obtained by polycondensation of a polyhydric carboxylic acid or a lower alkyl ester thereof and a polyhydric alcohol having a melting temperature of 80 to 150 ° C. by a 1/2 method using a flow tester.

Further, in the toner of the present invention, the binder resin has a weight average molecular weight Mwf of 10,000 to 40, and a weight average molecular weight Mw.
If the ratio Mwf / Mnf between f and the number average molecular weight Mnf is Wmf, Wmf is 3 to 100, and if the ratio Mzf / Mnf between the Z average molecular weight Mzf and the number average molecular weight Mnf is Wzf, Wzf is 10 to 2000, A polyester resin obtained by polycondensation of a polyhydric carboxylic acid or a lower alkyl ester thereof and a polyhydric alcohol having a melting temperature of 80 to 150 ° C. by a 1/2 method using a flow tester. Average molecular weight M
When wv is 8000 to 300,000, and the ratio Mwv / Mnv between the weight average molecular weight Mwv and the number average molecular weight Mnv is Wmv,
Wmv is 2 to 100, and when the ratio Mzv / Mnv of Z average molecular weight Mzv and number average molecular weight Mnv is Wzv, Wzv
Is 8 to 1200 and Mwf / Mwv is 1.2 to 1
0, Wmf / Wmv is 1.2 to 10, and Wzf / Wzv is 2.2 to 30.

[0053]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Digital high image quality, high color reproducibility color, and high transparency and anti-offset can be achieved without using offset preventing oil in the fixing roller. The toner of the present embodiment makes it possible to achieve both the prevention of the occurrence of vertical stripes due to roller flaws and blade fusion in component development, the failure of cleaning of the intermediate transfer member, and the failure of scraping of the cleaning roller.

Heretofore, in order to improve color fixability, a sharp-melt, low-softening binder resin having a low molecular weight distribution and a small molecular weight distribution has been used. In this configuration, since an offset occurs, light transmission can be ensured only in a configuration in which oil is applied to the fixing roller. In a configuration in which a release agent such as wax is added to a sharp-melt low-softening binder resin in order to realize oil-less fixing, a release agent, a pigment,
Difficulty dispersing charge control agents, etc., lowers transferability due to fogging and poor charging, worsens cleaning performance, filming on photoconductors and developing rollers, deteriorates charging rise, and reduces image quality due to repeated charge reduction Problems such as a decrease in concentration occurred. It is difficult to disperse the wax in the polyester resin, and the image quality such as fogging is deteriorated due to a decrease in chargeability. In addition, color toner becomes turbid, and clear light transmission cannot be obtained.

In order to satisfy the above-mentioned required properties, efforts are being made to increase the dispersion of the wax. However, simply dispersing the wax in a spherical shape simply reduces the binder resin necessary for improving the offset property. In this case, it is not possible to achieve both rapid leaching of the wax and stable development characteristics, color reproducibility, and OHP transmissivity.

The toner according to the present embodiment makes it possible to achieve both of these various electrophotographic characteristics.

That is, by dispersing the wax in a matrix in a linear or rod form in the binder resin,
Seepage from the surface is faster than in the case where the particles are dispersed spherically. This is considered to be due to the fact that when the binder resin is heated and softened at the time of fixing, the force for pushing out the wax from the binder resin increases.

On the other hand, when used at room temperature, the contact area between the wax and the binder resin is large, so that the wax is less likely to be separated or released, which is advantageous for preventing filming.

Further, since the arrangement of the dispersed waxes is kept in a parallel state, light is not irregularly reflected even after fixing, and the OHP translucency and color reproducibility are not hindered.

Further, the ratio DL / m of the major axis diameter DL (m) to the minor axis diameter DS (m) of each wax dispersed in the binder resin.
When the DS is 1.0 ≦ DL / DS ≦ 2.0, the ratio of Q1 to the total number of waxes is 2.0 <DL / D.
The ratio of S ≦ 5.0 is represented by Q2, 5.0 <DL / D
Q3, 10.0 <DL
Assuming that the ratio of / DS is Q4, high OHP transmissivity and long-term filming resistance can be realized by applying no fixing oil by using the following formula (Equation 3).

[0061]

(Equation 3)

The DL / DS is a value indicating the anisotropy of the dispersed wax. The smaller this value is, the closer the dispersion form is to a spherical or square shape. When DL / DS is increased, the filming resistance is improved, but the leaching property from the binder resin is reduced, so that the offset prevention effect is reduced. Only when DL / DS is within the above range, the compatibility of characteristics can be achieved.

The wax has a minor axis diameter DS of 5 × 10
^{When it is -8 to} 3 × 10 ^-7 (m), the chargeability of the toner becomes uniform, and stable charge characteristics can be obtained over a long period of time. D
When S is less than 5 × 10 ⁻⁸ (m), the effect as a wax is not exhibited, and the offset property is deteriorated. 3 × 10 ^-7
If it is larger than (m), since the released wax is present in the toner, it adheres to the developing roller and the carrier and inhibits toner charging. For this reason, as the usage time increases, the toner charge amount decreases, resulting in a poor image.

Further, the volume average particle diameter of the toner is defined as DT.
(M), the major axis diameter DL of the wax in the binder resin
When (m) satisfies DT / DL> 4, it is possible to prevent the adhesion to the developing roller and the intermediate transfer member and the generation of the damage to the fixing belt for a long time. If the DT / DL is 4 or less, the wax component is released, causing filming. Further, the fluidity of the toner is reduced, and the thermal stability during storage, which is called storage stability, is reduced.

Further, the volume average particle diameter of the toner is 4 to 9 ×
It is 10 ^-6 m, preferably 5 to 8 × 10 ^-6 m. 9x
If it is larger than 10 ^-6 m, the resolution is lowered and high image quality is not obtained. If it is smaller than 4 × 10 ^-6 m, toner aggregation becomes strong and background fog increases.

By specifying the molecular weights of the toner and the polyester resin, the dispersibility of the wax can be improved, and the chargeability can be stabilized. In addition, toner aggregation can be prevented, and filming on the photoreceptor, the intermediate transfer member, and the developing roller can be prevented even when used continuously for a long period of time. We have created a configuration that can ensure high translucency and high color reproducibility during fixing, and can extend the offset range to higher temperatures without the need for fixing oil. In development, a stronger stress is applied to increase the charging property, and a strong load is also applied to cleaning of the intermediate transfer member in order to increase the cleaning property. In addition, the durability, transferability, recyclability, and chargeability are improved while maintaining high light transmission even when strong stress is applied to the toner due to the configuration in which the developing unit revolves. It has been found that it is possible to better balance durability.

Hereinafter, the toner composition, the carrier, and the evaluation and measurement method will be described in this order.

1. Toner 1-1. Composition (1) Binder Resin The binder resin of the toner includes an alcohol component and a carboxylic acid,
Polyester resins obtained by polycondensation with carboxylic acid components such as carboxylic esters and carboxylic anhydrides are preferably used.

The polyhydric alcohol component includes ethylene glycol, propylene glycol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexanediol, Neopentylene glycol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, bisphenol A, glycerin, sorbitol, 1,4-sorbitan, trimethylolpropane, and the like can be used. , Derivatives thereof, alkylene oxide adducts thereof, and hydrogenated bisphenol A are preferably used.

Examples of the polycarboxylic acid component include maleic acid, maleic anhydride, fumaric acid, phthalic acid, terephthalic acid, isophthalic acid, malonic acid, succinic acid, glutaric acid,
Dodecenyl succinic acid, n-dodecenyl succinic acid, n-octyl succinic acid, 1,2,4-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid,
2,4-Naphthalenetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, trimellitic acid, pyromellitic acid and lower alkyl esters of these acids can be used.

Further, the obtained polyester resin may be reacted with an isocyanate compound to be used as a urethane-modified polyester. Examples of the isocyanate compound used include hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, and tetramethyl xylylene diisocyanate. The amount of the isocyanate compound used depends on the number of hydroxyl groups 1 in the polyester resin before urethane modification.
0.5 to 0.95 mole equivalent per mole equivalent is preferred.

The binder resin is used to ensure toughness to the extent that the toner is not destroyed at the time of development or cleaning, or to obtain pulverizability at the time of production and dispersibility of a release component represented by wax at the time of melt-kneading. To improve
It is necessary to specify a softening point, a weight average molecular weight, a number average molecular weight, a glass transition point, and a THF insoluble content.

The weight average molecular weight Mwf of the polyester resin
If the ratio Mwf / Mnf of the weight average molecular weight Mwf to the number average molecular weight Mnf is Wmf, Wmf is 3 to 100, the Z average molecular weight Mzf and the number average molecular weight Mnf
Assuming that the ratio Mzf / Mnf is Wzf, Wzf is 10 to
2000, the melting temperature (hereinafter softening point) by the 1/2 method using a Koka flow tester is 80 to 150 ° C, the outflow starting temperature is 80 to 120 ° C, and the glass transition point of the resin is 45 to 65 ° C.
It is preferable to use a polyester resin having a range of the above as a component.

The Z-average molecular weight best represents the size and amount of the molecular weight in the tailing portion on the high molecular weight side, and has a great influence on the dispersibility, fixability and offset resistance of the internal additive during kneading. As Mzf increases, the resin strength increases, the viscosity during hot-melt kneading increases, and the dispersibility improves significantly.
Fogging and toner scattering can be suppressed, and the effect of suppressing environmental fluctuations under high temperature, low humidity, and high humidity can be obtained. The fact that Mzf / Mnf is large means that the molecular weight distribution is broadly extended to the ultrahigh molecular weight region.

Preferably, Mwf is 11,000 to 300,000,
Wmf is 3 to 30, Wzf is 10 to 500, and softening point is 9
It is preferable to use a polyester resin having a temperature of 0 to 150 ° C, an outflow starting temperature of 85 to 115 ° C, and a glass transition point of 52 to 65 ° C.

More preferably, Mwf is 12,000 to 10
A polyester resin having a Wmf of 3 to 10, a Wzf of 10 to 100, a softening point of 90 to 140 ° C, an outflow starting temperature of 85 to 110 ° C, and a glass transition point of 53 to 59 ° C. Is preferred.

When the binder resin has an Mwf of less than 10,000 and a Wm
f is less than 3, Wzf is less than 10, softening point is less than 80 ° C, outflow starting temperature is less than 80 ° C,
When the glass transition point is lower than 45 ° C., the dispersibility at the time of kneading is reduced, which causes an increase in fog and a deterioration in durability. In addition, kneading stress during kneading is not sufficiently applied, and the molecular weight cannot be maintained at an appropriate value. The dispersibility of the wax is reduced, and the offset resistance and the high-temperature preservability are deteriorated. Further, the cleaning of the intermediate transfer member is poor, and the filming on the photosensitive member occurs.

When Mwf of the binder resin is larger than 400,000,
mf is larger than 100, Wzf is larger than 2000, softening point is larger than 150 ° C., and outflow starting temperature 120
When the glass transition temperature of 65 ° C. is higher than 65 ° C., the load during the kneading process becomes excessive, leading to an extreme decrease in productivity, a decrease in light transmittance in a color image, and a decrease in fixing strength.

The binder resin contains 5% by weight of a THF-insoluble component.
Hereinafter, preferably, it has no THF-insoluble component. The THF-insoluble component is a gelled ultra-high molecular component, and although the offset resistance is improved, if the THF-insoluble component is more than 5% by weight, it becomes a factor of deteriorating the translucency of a color image and deteriorating the image quality. I'm going.

By kneading the above-mentioned binder resin with a strong compressive shearing force in the melt-kneading process, it is possible to exhibit unprecedented characteristics. By fixing without using oil, it is possible to achieve both high translucency and offset resistance of the color toner. In other words, the binder resin to which the ultra-high molecular weight component has been imparted has a high shear force to lower the ultra-high molecular weight component to have a low molecular weight, thereby exhibiting high translucency. The nature can be satisfied. In addition, since it has an ultra-high molecular weight component, a high shear force is applied during kneading, so that wax can be more uniformly dispersed, light transmittance is improved, non-offset properties, high image quality, and high color reproduction are improved. can get.

If the weight average molecular weight Mwv of the toner after the melt kneading treatment is 8,000 to 300,000, and the ratio Mwv / Mnv of the weight average molecular weight Mwv to the number average molecular weight Mnv is Wmv, Wmv is 2 to 100 and Z average molecular weight Mzv is Assuming that the ratio Mzv / Mnv of the number average molecular weight Mnv is Wzv, W
It is preferable that zv is 8-1200. By kneading the toner in this proper range with a high compressive shearing force, it is possible to achieve both high translucency and offset resistance of the color toner by fixing without using oil.

Preferably, Mwv is 8,000 to 200,000, W
It is preferable that mv is 2 to 30 and Wzv is 8 to 100.

More preferably, Mwv is 8000 to 10
Preferably, Wmv is 2 to 10, and Wzv is 8 to 50.

Mwv is smaller than 8000 and Wmv is 2
If Wzv is smaller than 8, kneading stress is not sufficiently applied, and the molecular weight cannot be maintained at an appropriate value. The dispersibility of the fixing aid is reduced, and the offset resistance and the high-temperature storage stability are deteriorated. Further, poor cleaning on the intermediate transfer member and filming on the photosensitive member occur.

When Mwv of the binder resin is larger than 300,000, W
When mv is greater than 100 and Wzv is greater than 1200, the load during the kneading process becomes excessive, leading to an extreme decrease in productivity and a decrease in fixing strength due to a decrease in translucency in a color image.

Therefore, when the molecular weight of the resin is small, an appropriate compressive shearing force cannot be received from the roller, and the dispersibility of the internal additive in the binder resin cannot be improved, and offset occurs. That is, it is necessary to have a molecular weight of a certain value or more.

When Mwf / Mwv is 1.2 to 10, W
mf / Wmv is 1.2 to 10, Wzf / Wzv is 2.2
This can be achieved by being within the range of ~ 30.

More preferably, Mwf / Mwv is 1.2 or more.
5, Wmf / Wmv is 1.2 to 5, Wzf / Wzv is 3
The range of ~ 20 is preferable.

More preferably, Mwf / Mwv is 1.5
-4, Wmf / Wmv is preferably 1.5-3, and Wzf / Wzv is preferably 3-15.

If Mwf / Mwv is smaller than 1.2 and Wm
f / Wmv is smaller than 1.2 and Wzf / Wzv is 2.
If it is less than 2, kneading stress during kneading is not sufficiently applied, and the molecular weight cannot be maintained at an appropriate value. The translucency does not improve. The dispersibility of the wax is reduced, and the offset resistance and the high-temperature preservability are deteriorated. Further, the cleaning of the intermediate transfer member is poor, and the filming on the photosensitive member occurs.

If Mwf / Mwv is greater than 10, Wmf
When / Wmv is greater than 10 and Wzf / Wzv is greater than 30, the pressure of the shearing force is excessively exerted, and conversely, the internal additives such as the charge control agent mutually aggregate, leading to a decrease in dispersibility, and This leads to an increase in fog, a reduction in image density, and the occurrence of transfer failure during the non-process. In particular, this phenomenon occurs more remarkably when a salicylic acid metal complex or a benzylic acid metal complex is used as a charge control agent in the polyester resin shown below.

(2) Wax The wax has an acid value of 30 to 60 mg KOH / g and a melting point of 90.
It is a configuration in which a hydrocarbon wax having an ester bond or an amide bond and having a penetration at -120 ° C and 25 ° C of 2 or less is internally added. Further, fixing properties can be further improved by specifying the molecular weight and the molecular weight distribution of the toner and the binder resin. Without deteriorating the high-temperature storability of the toner, it has excellent non-offset release properties without using fixing oil,
In addition, the transmissivity is not impaired, and the effect of reducing the charge amount during repeated use is exhibited.

However, the state of dispersion when added to the binder resin greatly affects the fixing properties such as releasability and translucency and the developing properties such as charge stabilization. If the dispersion state is not proper, vertical streaks on the developing roller, filming on the intermediate transfer member, poor scraping with the cleaning roller, and damage to the fixing belt will occur. Therefore, it is important to make the dispersion state in the resin appropriate,
The molecular weight distributions of the toner and the binder resin are as described below. Further, it is a solution to perform the melt-kneading method under appropriate conditions.

The ester bond of the hydrocarbon wax is preferably obtained by the reaction of a long-chain alkyl alcohol having 5 to 62 carbon atoms, an unsaturated polycarboxylic acid or an anhydride thereof. If the carbon number of the long-chain alkyl is less than 5, the releasing effect is weakened and the fixing offset property is reduced. When the carbon number of the long-chain alkyl is larger than 62, the dispersibility in the binder resin is deteriorated. If the acid value is less than 30 mgKOH / g, the dispersibility will decrease. If the acid value is greater than 60 mgKOH / g, the moisture resistance will decrease and the fog under high humidity will increase. If the melting point is lower than 90 ° C., the storability of the toner decreases. If the melting point is higher than 120 ° C., the releasing effect is weakened, and the non-offset temperature width is narrowed. The translucency of a color image is reduced, and the color reproducibility is reduced. If the penetration at 25 ° C. is greater than 2, the toughness is reduced, and filming occurs on the photoreceptor and the intermediate transfer member during long-term use.

As the alcohol, those having a long alkyl chain such as octanol, dodecanol, stearyl alcohol, nonacosanol and pentadecanol can be used. N-methylhexylamine as amines,
Nonylamine, stearylamine, nonadecylamine and the like can also be suitably used. As the unsaturated polycarboxylic acid or its anhydride, one or more of maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride and the like can be used. As the synthetic hydrocarbon wax, polyethylene, polypropylene, Fischer-Tropsch wax, α-olefin and the like can be suitably used. The unsaturated polycarboxylic acid or its anhydride is polymerized using an alcohol or an amine, and then this is added to a synthetic hydrocarbon wax in the presence of diculum peroxide or tert-butyl peroxyisopropyl monocarbonate. Can be obtained. The addition amount is 5-1 to 100 parts by weight of the binder resin.
2 parts by weight are preferred. If it is 5 or less, it is difficult to obtain a releasing effect. If it is 12 or more, not only does the fluidity of the toner decrease, but even if it is added more, the effect is not improved due to saturation.

The wax has an endothermic peak by DSC at 65 to 90 ° C., and is particularly suitable for carnauba wax, candelilla wax, hydrogenated jojoba oil, rice wax, hydrogenated lanolin, medofoam oil or derivatives thereof. Of these, at least one type is used. Since these waxes have an endothermic peak of 65 to 90 ° C., they melt at a lower temperature than the binder resin of the toner and exude to the toner surface. For this reason, at the time of fixing, the unevenness of the image surface is filled to create a smooth surface. For this reason, OHP translucency improves.

The amount of addition of these waxes was 100
0.5 to 10 parts by weight per part by weight is preferred. If the amount is less than 0.5 parts by weight, no effect is obtained. If the amount is more than 10 parts by weight, filming occurs on the photoreceptor, and the charge on the photoreceptor surface is lost in a high-humidity environment, causing image deletion.

(3) Colorant As the pigment or dye used for the colorant, carbon black, iron black, graphite, nigrosine, metal complex of azo dye, anthraquinone dye, phthalocyanine blue, Dupont oil red, aniline blue, benzene yellow , Hansa Yellow, Rose Bengal, Rhodamine Lake, Alizarin Lake, C.I. I. Pigment Red 22, 31, 48-1, 48-3, 53-1, 57
-1, 60, C.I. I. Pigment Yellow 12, 1
3, 14, 17, 81, 97, 154, 155, 17
4,180, C.I. I. Pigment Blue 15, 15-
3, 15-4, 15-6, 60, and mixtures thereof can be used. If necessary, magnetic particles can be added as a coloring agent. The magnetic particles include
Metal powders such as iron, manganese, nickel, cobalt and iron,
Ferrite powder of manganese, nickel, cobalt, zinc, or the like is used. The average particle size of the powder is 1 μm or less, especially 0.1 μm.
Preferably it is 6 μm or less.

The content of the coloring agent is preferably 2 to 15% by weight. When the content of the coloring agent is less than 2% by weight, the coloring power becomes weak, and when it exceeds 15% by weight, the OHP transmissivity is reduced even if the surface of the fixed image is smoothed.

The colorant may be prepared and used in advance by means of melt kneading with a binder resin to improve the dispersibility of the colorant, that is, a so-called master batch. In this case, the content of the coloring agent in the master batch is preferably 60% by weight or less. If the amount exceeds 60% by weight, the dispersibility of the colorant is reduced, so that the OHP light transmission is reduced even when the surface of the fixed image is smoothed.

(4) External Additives External additives include fine powders of metal oxides such as silica, alumina, titania, zirconia, magnesia, ferrite, and magnetite; carbides such as tungsten carbide;
In addition, nitrides, titanates such as barium titanate, calcium titanate and strontium titanate, zirconates such as barium zirconate, calcium zirconate and strontium zirconate, and mixtures thereof are used. The external additive may be subjected to a surface treatment such as a hydrophobic treatment as needed.

(5) Others A charge controlling agent may be used for the purpose of controlling the triboelectric charging property of the toner. There are two types of charge control agents, one for positive charge control and the other for negative charge control, and these can be used alone or in combination depending on the purpose of use. Examples of the charge control agent for controlling the positive charge include organic compounds having a basic nitrogen atom, such as basic dyes, nigrosine, pyrimidine compounds, aminosilanes, and quaternary ammonium salts.
As the charge control agent for negative charge control, metal-containing azo dyes,
Examples thereof include a metal salt of an alkyl salicylic acid, a metal salt of a naphthenic acid, and a fatty acid soap, and a metal salicylate complex and a metal benzylate complex are particularly preferably used.

Further, if necessary, Teflon (registered trademark), zinc stearate, polyvinylidene fluoride and the like can be used as a release agent, a fluidity auxiliary, a charge auxiliary, and a cleaning auxiliary.

1-2. Manufacturing Method The toner is manufactured by at least the steps of premixing, kneading, pulverizing, fine powder classification, and external addition.

The premixing step is a treatment for uniformly dispersing the binder resin and the colorant or the like by a mixer or the like having a stirring blade, and a known treatment method is used.

In the following examples, the Henschel mixer F
The mixing process is performed with M-20B (manufactured by Mitsui Miike Kakoki Co., Ltd.).

In the kneading step, the mixed material is heated to disperse the colorant and the like in the binder resin by a shearing force. The kneading includes a two-roll type, a three-roll type, and a uniaxial screw. A known heating kneader that heats and kneads a kneaded material such as a mold, a twin-screw mold, a Banbury mixer, and the like by applying a shearing force can be used. In the following examples, a roll-type kneader KNEADEX (manufactured by Mitsui Mining Co., Ltd.)
Is used to heat and knead the mixture.

Next, the lump obtained by the kneading treatment is coarsely pulverized by a cutter mill or the like, and then finely pulverized. In this fine pulverization step, a pneumatic pulverizer represented by a jet mill pulverizer or a mechanical pulverizer represented by a rotor type can be used.
In the coarse pulverization step before the fine pulverization, the raw material of the fine pulverization is preferably set to 2 mm or less in order to suppress the generation of the ultrafine toner and loose substances during the fine pulverization and to improve the yield.
Or introduce a medium grinding process between the coarse grinding and fine grinding processes,
It is also preferable that the size of the pulverized raw material is set to 100 μm or less. After the fine pulverizing step, a fine powder classification step of removing fine powder by classification is performed.

The external addition process is a process in which an external additive is added and mixed. (In the following examples, the external addition treatment step is performed before or after the fine powder classification step.) A known mixer can be used as the mixer.

Part or all of the classified fine powder separated in the fine powder classification step can be returned to the premixing step or the kneading step and used. The classified fine powder may be solidified into pellets to improve the premixability. A roller compactor or the like can be used for solidification.

[0111] 2. Carrier In the case of two-component development, a carrier that is magnetic particles and a toner are mixed and used. The carrier is prepared by providing a resin coating layer on the surface of the ferrite particles. Ferrite is mainly composed of Fe ₂ O ₃ , NiO, CuO, CoO,
MgO, ZnO, MnCO ₃ , BaCO ₃ , and SrCO ₃ are mixed and used as a raw material.

The ferrite particles may be prepared by either a wet method or a dry method, but the dry method is preferred. In the dry method, the raw materials are mixed, pre-fired, finely ground in a ball mill or the like in water, and further added with PVA (polyvinyl alcohol), an antifoaming agent, and a dispersant as a binder to form a slurry for granulation. This slurry is granulated while heating and drying with a spray drier to form granules, which are then calcined. Main firing is 900 to 1400
C. for 10 to 30 hours, and then crushed and classified to obtain ferrite particles.

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

As the resin used for the resin coating layer, a fluorine resin or a silicone resin is used. As the carbon black contained in the resin coating layer, carbon blacks of various production methods are used, and oil furnace carbon and acetylene black are preferable. Further, the carbon black surface may be used after being grafted or oxidized.

The average particle size of the carrier is 40 to 100 × 1.
0 ^-6 m is preferred. Average particle size of carrier is 40 × 10 ^-6
If it is less than m, the carrier is easily developed on the photoconductor, and the photoconductor is easily damaged in the cleaning step. On the other hand, when it exceeds 100 × 10 ⁻⁶ m, the toner holding power of the carrier becomes weak, and toner scattering occurs.

3. Evaluation measurement method (1) Softening point The softening point was measured using the Shimadzu Koka type flow tester (CFT-
While heating a 1 cm ³ sample at a heating rate of 6 ° C./min according to 500 C), a load of 20 kg / cm ² is applied by a plunger, and a nozzle having a diameter of 1 mm and a length of 1 mm is extruded. From the relationship between the amount of plunger descent and the temperature rise temperature characteristic, the temperature corresponding to one half of the characteristic line is taken as the softening point.

(2) Molecular weight distribution The molecular weight was determined by gel permeation chromatography (G) using several types of monodisperse polystyrene as standard samples.
PC) is used. 1 ml / min using tetrahydrofuran (THF) as a solvent at a temperature of 25 ° C.
, And 10 mg of a sample solution of tetrahydrofuran having a concentration of 0.5 g / dl is injected into the sample at a flow rate of 0.5 g / dl for measurement. As the measurement condition, a condition is selected in which the molecular weight distribution of the target sample is included in a range in which the logarithm of the molecular weight and the count number are linear in a calibration curve obtained from several types of monodisperse polystyrene standard samples.

(3) THF (tetrahydrofuran) -insoluble content This is the filter paper insoluble content (% by weight) when a sample was dissolved in THF and allowed to stand at room temperature. In the case of the binder resin, it indicates the content of the crosslinking component.

(4) Glass transition point, DSC endothermic peak temperature, and properties of wax The glass transition temperature (Tg) and DSC endothermic peak temperature were once measured up to 150 ° C. using a differential scanning calorimeter (DSC-50, manufactured by Shimadzu Corporation). It measured from the DSC curve at the time of raising a temperature and cooling at 7.5 degreeC / min.

The softening point of the wax is an index of the temperature at which the wax becomes molten, according to JIS K2207-6.4-.
93.

The penetration was measured at 25 ° C. in accordance with JIS K 2235-6.3-93 as an index indicating the hardness of the wax at room temperature.

(5) Particle Size Distribution The toner particle size distribution can be measured by various methods. In the present invention, a Coulter Multisizer (manufactured by Coulter Co., Ltd.) is used.
And a personal computer for data processing.

As an electrolytic solution, an Isoton 2 electrolytic solution (manufactured by Coulter Co., Ltd.) was used.

About 2 mg of the toner to be measured was added to about 50 ml of a surfactant (sodium lauryl sulfate) to which a 1% concentration was added to the electrolytic solution, and the mixture was ultrasonically dispersed for 3 minutes to obtain a measurement sample.

The aperture diameter of the Coulter Multisizer was 70 × 10 ⁻⁶ m. When an aperture of this size is used, the particle size distribution measurement range is 1.26 × 10 ^{−6 to} 5
Although it is 0.8 × 10 ⁻⁶ m, the area of less than 2 × 10 ⁻⁶ m is not practical because the measurement accuracy and the reproducibility of the measurement are low due to the influence of external noise and the like. Therefore, the measurement area is set to 2.00 × 10 ^-6
５50.8 × 10 ⁻⁶ m. In this region, the volume average particle diameter of the toner was calculated. The volume average particle diameter Dc of the carrier is:
The measurement was performed using a Nikkiso Microtrack.

(6) Charge Amount The charge in the case of two-component development was measured using a blow-off measuring device TB-200 manufactured by Toshiba Chemical Corporation. The measurement sample was prepared by adding a carbon black having a DBP oil absorption of 360 ml / 100 g, a specific surface area of 800 m 2 / g and a PH of 8 to a carrier.
60% average particle size coated with silicone resin
Cu—Zn—having a volume resistance of 3 × 10 ⁸ Ωcm at × 10 ⁻⁶ m
Using Fe ₂ O ₃ particles, the toner was mixed so that the toner concentration became 5.0%, put in a 100 ml polyethylene bottle, and stirred at a rotation speed of 100 rpm for 10 minutes.

The DBP oil absorption was determined by measuring 20 g of a sample dried at 150 ° C. ± 1 ° C. for 1 hour with an absolute meter (Brave).
The mixture is charged into a mixing chamber having a spring tension of 2.68 kg / cm (manufactured by nder Co.), and after setting a limit switch to about 70% of the maximum torque in advance, the mixer is rotated. At the same time, DBP (specific gravity 1.045 to 1.05)
0 g / cm ³ ) 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 is determined from the amount of DBP added up to that time and the sample weight.

The pH was measured by adding 100 ml of distilled water to a sample of 10 g, boiling on a hot plate for 10 minutes, cooling to room temperature, removing the supernatant, separating and measuring the pH of the muddy substance with a glass electrode PH meter. .

The volume resistance of the carrier is 2 × 1 cm.
While the electrodes were facing each other at an interval of 2 mm, 0.2 g of a sample carrier was charged, a bridge was formed between the electrodes by magnets facing the outside of the electrodes, and 1000 V was applied to the electrodes for measurement.

Further, the toner charge amount in the case of one-component development was measured by a Faraday cage by sucking the toner from the surface of the developing roller.

(7) Image Density The image density was measured with a reflection densitometer (Macbeth) and evaluated.

(8) OHP translucent OHP sheet (CG3700; manufactured by 3M) on which a solid image with an attached amount of 0.4 mg / cm ² was prepared was used as a measurement sample. The OHP translucency measured the transmittance | permeability of 700 nm light with the spectrophotometer U-3200 (made by Hitachi, Ltd.).

(9) Hot Offset Property The hot offset property was quantified by the temperature at which hot offset was started. Process speed 52.5mm
/ S, the fixing device temperature was increased every 5 ° C., and the temperature at which hot offset was started was visually evaluated.

(10) Particle Size of Wax Dispersion The dispersion shape and particle size of the wax were measured by TEM (transmission electron microscope) after kneading the sample into a thin section with a microtome, developing the wax by osmium staining, and then developing the wax. With the observation magnification set to 30,000 times, a total of 500 particles were measured in a plurality of visual fields.

In the developing process of this embodiment, a thin toner layer is brought into contact with an elastic or rigid developing roller with a toner layer regulating elastic blade such as rubber or metal or a rotating toner layer regulating roller by a constant pressure. It is configured to be formed and developed by contact or non-contact with the photoconductor. As a one-component developing method, a sponge-based supply roller made of a urethane resin is brought into contact with a development roller made of a silicone resin or a urethane resin with a fixed bite amount, and toner is supplied from the supply roller to the development roller. A thin toner layer is formed by contacting an elastic rubber or metal stainless steel doctor blade, or by rotating a metallic toner layer regulating roller against the developing roller in an opposite direction (in the same direction) to form a thin layer of toner. A developing method of forming a toner image by applying a direct current or an alternating current with or without contact with a body is preferably used.

At this time, the supply roller and the developing roller are rotated in the same direction, and the peripheral speeds of the developing roller and the supply roller are set to 1: 1 to 1
The configuration is such that the developing roller is advanced at a ratio of 0.8: 0.2. The developing roller is 9.8 × 10 ^2-
The electrostatic latent image on the photoreceptor is developed by being pressed at a pressure of 9.8 × 10 ⁴ (N / m ² ). The elastic blade is 5 × 10 ³
A toner layer is formed by pressing against the developing roller at a pressure of about 5 × 10 ⁵ (N / m ² ).

Further, in order to control the amount of toner supplied from the toner reservoir to the amount of toner transported on the developing roller when transporting the toner to the developing roller, a sponge-shaped supply roller made of urethane resin or the like is used. A configuration is adopted in which the developing roller is brought into contact with the developing roller at a fixed bite amount of 0.1 to 1 mm.

In order to control the amount of toner supplied from the toner reservoir to the amount of toner transported on the developing roller when the toner is transported onto the developing roller, a sponge-like supply roller made of urethane resin or the like is used. And a configuration provided in contact therewith. This is an effective means for regulating the transport amount of the toner to a fixed amount.

However, in this configuration, if used for a long period of time, scratches on the developing roller and image defects that cause vertical streaks on the image due to the adhesion of foreign matter to the blade are likely to occur.
In particular, the use of a low-softening binder resin or a toner to which a low-melting-point release agent Wax is added to improve the color fixing property is more remarkable.

In addition, during the long-term continuous use, the amount of toner transported on the developing roller is reduced, and when a solid black image is taken, the solid follow-up defect in which the density of the latter half of the image is partially reduced easily occurs. . When the charge amount of the toner on the developing roller was measured by a suction method, it was found that the charge amount was greatly reduced. To further pursue, the charge amount of the toner on the supply roller portion has increased significantly.In other words, the decrease in image density does not mean that the charge amount of the toner has decreased, but the supply roller portion before being supplied to the developing roller. This is because the charging capability has increased and the supply capability from the supply roller to the developing roller has decreased. Therefore, a configuration that can secure the image density while preventing toner scattering is required. It is also effective to increase the pressing force of the doctor blade to increase the charging ability of the toner, but the toner is likely to be fused, and the developing roller is damaged.

Thus, it has been found that the above problem can be solved by a configuration in which wax is dispersed in a binder resin in a matrix in a linear or rod form, or a configuration in which adjacent wax arrangements are kept in a parallel state.

In order to improve color translucency, oil-less fixing non-offset properties, and storage stability characteristics, if the wax is finely dispersed in a spherical shape, the wax will be detached or released from the binder resin during long-term use. I do. To achieve oil-less fixing, it is necessary to add a large amount of highly releasable wax, but when it is finely dispersed in a spherical form, it is a dispersed state that achieves both non-offset properties, storage stability, and development stability. Is too narrow to stably produce toner. Further, since the toner charge rising property is affected by the surrounding environment, particularly the humidity, environmental stability is also lacking. When the wax is dispersed linearly or in a rod shape, not only can the exuding property of the wax at the time of softening the binder resin and the preservability be achieved, but also the charging startability and the stability are improved. This is thought to be due to the apparent decrease in the amount of wax exposed on the surface of the binder resin.

In the mechanism for regulating the toner layer by bringing the rotating toner layer regulating roller into contact with the developing roller with a constant pressure, the present toner mode allows uniform regulation of the layer. Although the rotating toner layer regulating roller exerts less stress on the toner than the elastic blade and is less likely to be charged, the toner layer has a high charge rising characteristic, so that the toner layer can be regulated uniformly. Further, since the toner base contains a wax having a high release property, the toner tends to slip easily between the rollers and the chargeability tends to be weak. However, the effect of uniformly regulating the toner layer can be obtained by the high charge rising characteristic. Further, the stability is further improved by specifying the molecular weight and the molecular weight distribution of the toner and the binder resin.

It has been found that by making the wax dispersed in the present embodiment, it is possible to prevent generation of vertical streaks on the developing roller, poor solid followability, and fusion of toner without sacrificing fixing characteristics. . Due to this dispersion state, the fluidity of the toner can be maintained, the toner can be smoothly transported on the developing roller, and the transport state can be constantly stabilized. In particular, it is highly effective in stabilizing the transport state under high humidity.

In the present embodiment, the primary transfer process of transferring the toner image formed on the surface of the photoreceptor to the surface of the endless intermediate transfer member by contacting the surface of the intermediate transfer member with the surface of the photoreceptor. Is repeatedly performed a plurality of times, and thereafter, a secondary transfer process of collectively transferring the overlap transfer toner image formed on the surface of the intermediate transfer member to a transfer material such as copy paper by performing the plurality of repetitions of the primary transfer process is performed. It is suitably used in an electrophotographic apparatus having a transfer system configured to be executed. At this time, the photosensitive member and the intermediate transfer member are pressed against each other at a pressure of 9.8 × 10 ² to 2 × 10 ⁵ (N / m ² ), and the toner on the photosensitive member is transferred. In addition, the toner image formed on the surface of the intermediate transfer member is transferred to the surface of the intermediate transfer member by a transfer member via a recording sheet at 5 × 10 ³ to 2 × 10 ⁵ (N /
m ² ) The toner is transferred onto the recording material by pressing with pressure.

At this time, it is necessary to clean and remove the toner remaining without being transferred to the transfer material at the time of the secondary transfer, and a roller to which a bias is applied, a fur brush, or the like is used. At this time, if the toner is not easily cleaned, the toner may cause filming due to contact with the intermediate transfer member. Further, when the toner removed by the roller is scraped from the roller by a metal plate, the toner is fused to the metal plate, and a scraping defect occurs. In particular, the use of a low-softening binder resin to develop the glossiness of color images and the color fixability of high translucency,
In the case of a toner to which a low-melting-point release wax has been added, the toner is more likely to occur.

Therefore, by using the toner configuration of the present embodiment, the charging property of the toner is stabilized, the toner has a uniform charging property, the background fog is reduced, and the hollowing out at the time of transfer can be prevented. It is possible to obtain efficiency. Regarding the cleaning property, if the charging property of the toner is too strong to the negative polarity, cleaning failure occurs, which leads to filming and scraping failure. By adopting a configuration having a wax dispersion state suitable for the cleaning property, the cleaning property is improved and filming and scraping defects can be avoided.

In this embodiment, the image forming apparatus further comprises a rotating photosensitive member and developing means having toners of different colors.
The image forming unit group includes a plurality of movable image forming units that form toner images of different colors on the photoconductor, and the entire image forming unit group is rotated and moved. It is suitably used for a color electrophotographic apparatus for forming a color image by transferring the toner images of different colors formed on the transfer material while superimposing and transferring them on a transfer material.

Since the image forming unit is configured so that the entire unit revolves while the photoconductor and the developing roller rotate, the toner may temporarily come into contact with and separate from the developing roller and the supply roller in the developing device. Poor charge build-up in the early stage of development causes background fog.

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

Further, a situation in which the waste toner cleaned from the photoreceptor and collected from the photoreceptor repeatedly adheres to and separates from the photoreceptor always occurs. When the waste toner repeatedly comes into contact with and separates from the photoconductor, filming on the photoconductor is more likely to occur, which causes a reduction in the life of the photoconductor.

Therefore, by the dispersion state of the wax in the toner of the present embodiment, the charge rising property of the toner is stabilized,
It has a uniform charging property and can suppress the occurrence of background fog at the beginning of development. Due to the dispersion state, the releasability of the material, and the proper charging property of the toner, no fusing phenomenon and no image noise such as black stripes and white stripes are observed in the image forming unit. Further, occurrence of filming on the photoconductor due to repeated contact and separation of the waste toner with the photoconductor can be prevented.

Further, in this embodiment, the transfer material is inserted between the image carrier and the conductive elastic roller, and a transfer bias voltage is applied to the conductive elastic roller so that the toner image on the image carrier is removed. Is suitably used for an electrophotographic apparatus having a toner transfer system for transferring the toner to a transfer material by electrostatic force. This is because such a toner transfer system is a contact transfer, and a mechanical force other than an electric force acts on the transfer, so that the opposite polarity toner attached to the surface of the photoreceptor which should not be transferred is transferred or passed. In some cases, toner adhering to the surface of the photoreceptor in a non-paper state contaminates the surface of the transfer roller and contaminates the back surface of the transfer paper.

Therefore, by the wax dispersion state in the toner of the present embodiment, aggregation of the toner is suppressed and overcharging is prevented.
As a result, the chargeability can be stabilized, so that it is possible to prevent the dropout during transfer and to obtain high transfer efficiency. Further, it is possible to prevent occurrence of filming on the transfer member and the photosensitive member, and it is possible to prevent transfer paper from being contaminated by unnecessary toner particles. Also, scratches and filming on the transfer roller surface can be prevented, and image defects can also be prevented.

Further, in the present embodiment, the following charging, exposure, and cleaning steps are performed without a cleaning process step of recovering the toner remaining on the photoreceptor after the transfer process by cleaning.
It is suitably used for an electrophotographic apparatus having a cleaner-less process for performing a developing process as a basic configuration.

[0156] By the wax dispersion state in the toner of the present embodiment, aggregation of the toner is suppressed, overcharging is prevented, chargeability is stabilized, and high transfer efficiency can be obtained.
Further, the toner remaining in the non-image area can be satisfactorily recovered by development due to the main dispersion state, good chargeability, and releasability of the material. Therefore, there is no development memory in which the image pattern before the non-image portion remains.

In the present embodiment, the present invention is suitably used for an electrophotographic apparatus having a fixing process in which a belt-type fixing medium is used as a means for fixing toner. As the belt, a heat-resistant belt such as a nickel electroformed belt or a polyimide belt having heat resistance and flexibility is used. In order to improve the releasability, the surface layer is made of silicone rubber, fluoro rubber, or fluoro resin. Until now, these fixing belts have been coated with release oil to prevent offset. The use of a toner having high releasability without using oil eliminates the need to apply a release oil. However, if the release oil is not applied, the belt is likely to be charged, and if an unfixed toner image approaches the belt, the toner may fly due to the influence of the charging. In particular, it easily occurs under low temperature and low humidity. Also, the toner adds a certain amount of high molecular weight component to prevent high temperature offset,
When a certain amount of elastic element is provided, there is a case where the leading end is taken to the belt when the paper on which the thin vertical line pattern of the toner is drawn is separated from the belt having a large curvature. Also, compared to the conventional rigid fixing roller, in the case of an elastic belt type, there is a problem in that the life is shortened due to scratches due to oillessness.

Therefore, the use of the wax dispersion state, the binder resin, and the wax in the toner of the present embodiment makes it possible to prevent the occurrence of offset without using oil and to obtain high color translucency. The overcharging property of the toner can be suppressed, and the flying of the toner due to the charging action with the belt can be suppressed. In addition, it can be prevented by the effect of the molecular weight distribution and the slipperiness of the offset toner whose leading end portion is brought to the belt at the time of separation from the belt.

[0159]

(Embodiment 1) FIG. 1 is a sectional view showing the structure of an electrophotographic apparatus for forming a full-color image used in this embodiment. In this embodiment, a one-component developing system is used as a developing system, but the present invention is not limited to this, and a two-component developing system can also be used.

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

FIG. 2 shows the structure of the intermediate transfer belt unit 2.

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

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

The intermediate transfer belt 3 is set to a thickness of 100 μm
A first transfer roller 4 formed of an endless belt-shaped film made of semiconductive urethane as a base material, and formed of a urethane foam having a resistance of about 10 ⁶ Ω · cm to about 10 ⁸ Ω · cm on its periphery. Is wound around the second transfer roller 5 and the tension roller 6, and is configured to be movable in the direction of the arrow. Here, the circumferential length of the intermediate transfer belt 3 is the length in the longitudinal direction of A4 paper (297 mm) which is the maximum paper size.
The length is set to 360 mm by adding a length (63 mm) slightly longer than half the circumference of a photosensitive drum (diameter 30 mm) described later.

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

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

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

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

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

FIG. 3 shows an image forming unit.

11 is a photoreceptor, 30 is JIS-A hardness 60
The roller is pressed against the photoreceptor with a force of 21 N and is rotated in the direction of the arrow by a developing roller made of silicone rubber having a diameter of 18 mm. Reference numeral 31 denotes a supply roller made of urethane sponge having a diameter of 14 mm, and supplies the toner in the toner hopper to the developing roller. A metal plate 32 forms a toner layer on the developing roller. 33 is a power supply of 230 V DC, 50
An AC voltage of 0 Vpp (1 kHz) is applied. Numeral 24 is a charging roller of φ12 mm made of epichlorohydrin rubber to which a DC bias of -1 kV is applied. The photoconductor surface is charged to -450V. 26 is a developer reservoir, 34 is a cleaner, 27 is waste toner, and 28Bk is black toner.

Reference numeral 35 in FIG. 1 denotes a laser beam scanner disposed below the outer casing 1 of the printer, and includes a semiconductor laser (not shown), a scanner motor 35a, and a polygon mirror 3 (not shown).
5b, a lens system 35c, and the like. The pixel laser signal light 22 corresponding to the time-series electric pixel signal of the image information from the laser beam scanner unit 35 is supplied to an optical path window 36 formed between the image forming units 17Bk and 17Y.
Through a window 37 opened in a part of the shaft 20 to be incident on a fixed mirror 38 in the shaft 20, reflected and reflected by the exposure window 2 of the image forming unit 17 </ b> Bk at the image forming position 21.
5 and enters the image forming unit 17Bk almost horizontally,
Developer reservoir 2 arranged vertically in the image forming unit
The light passes through a passage between the cleaning member 6 and the cleaner 34 and is incident on an exposed portion on the left side surface of the photoreceptor 11, and is scanned and exposed in the generatrix direction.

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

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

Reference numeral 40 denotes a paper feed cassette provided on the lower side of the printer front plate 1A so as to protrude outward, and can set a plurality of papers S at the same time. 41a and 41b are paper conveyance timing rollers, 42a is a fixing roller, 42b is a pressing roller, 42c is a fixing belt made of fluoro rubber, 42d is a heating medium roller, 43 is provided between the third transfer roller 12 and the pair of fixing rollers. The paper guide plates 44a and 44b are paper discharge roller pairs disposed on the paper exit side of the fixing roller pair.

FIG. 4 shows the fixing process.

A belt 42c is hung between the fixing roller 42a and the heat roller 42d. Fixing roller 42
A predetermined load is applied between the pressure roller a and the pressure roller 42b, and a nip is formed between the belt and the pressure roller. A heater is provided inside the heat roller 42d,
A temperature sensor 51 is arranged on the outer surface.

The pressure roller 42b is pressed against the fixing roller 42a by the pressure spring 52. The recording material 54 having the toner 53 moves along the guide plate 55.

A fixing roller 42a as a fixing member has a rubber hardness (JIS-A) of 20 degrees according to JIS standard on the surface of a hollow roller core metal 56 made of aluminum having a length of 250 mm, an outer diameter of 14 mm and a thickness of 1 mm. The elastic layer 57 having a thickness of 3 mm made of silicone rubber is provided. A silicone rubber layer 58 having a thickness of 3 mm is formed thereon, and has an outer diameter of about 20 mm. It rotates at 100 mm / s by receiving a driving force from a driving motor (not shown).

The heat roller 42d has a thickness of 1 mm and an outer diameter of 2 mm.
It consists of a 0 mm aluminum hollow pipe. A 700 W lamp heater 58 for heating was provided inside, and the surface temperature of the fixing roller was controlled to 170 ° C. using a thermistor. When fixing an OHP image, 50 mm / s
And fixing at half speed.

The pressure roller 42b as a pressure member has a length of 250 mm and an outer diameter of 20 mm. It has an outer diameter of 16
mm and a 1 mm thick aluminum hollow roller core 59 made of aluminum have a rubber hardness (JIS
A) is provided with a 2 mm-thick elastic layer 60 made of 55 ° silicone rubber. The pressure roller 42b is rotatably installed, and forms a nip width of 5.0 mm with the fixing roller 1 by a spring-loaded spring 52 on one side 147N.

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

The operation will be described below.

First, as shown in FIG. 1, the image forming unit group 18 includes the black image forming unit 17Bk at the image forming position 2.
In one. At this time, the photoconductor 11 is in opposing contact with the first transfer roller 4 via the intermediate transfer belt 3.

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

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

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

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

In the above embodiment, a specific structure is used as the structure of the image forming unit. However, even in the case of an image forming unit having a structure using a conventional development method,
The essence and effect of the present invention do not change.

(Table 1) shows the binder resin used in this example, (Table 2) shows the wax, and (Table 3) shows the toner composition.

[0191]

[Table 1]

[0192]

[Table 2]

[0193]

[Table 3]

Materials other than the external additives shown in Table 3 were FM-
After pre-mixing with a 20B type Hensle mixer, 70
KNEADE 2-roll kneader with shaft temperature set to ℃
Using X, kneading was performed at a supply rate of 10 kg / h.
The conditions under which the kneading was performed were such that the front roll rotation speed was 1.6.
7 (s ^-1 ), and the number of rotations of the backing roll is 1.42.
(S ⁻¹ ), the front half temperature of the front roll is 70 ° C., the rear half temperature is 30 ° C., and the back roll temperature is 20 ° C.

The obtained lump was coarsely pulverized by a cutter mill having a mesh of 2 mm, and finely pulverized by an IDS-2 type jet mill.

The obtained finely pulverized powder was accurately classified by a multi-segment classification apparatus utilizing the Coanda effect to obtain a toner base.
The mixture was mixed with an external additive using a Henschel mixer to obtain a magenta toner. In addition, in Table 3, the addition amount represents a weight part. Further, the amount of the external additive added is
The value is based on parts by weight.

Similarly, toners TM-5 and TM-6 having the same composition as TM-1 and changing only wax to W-3 and W-4.
Also prototyped.

Table 4 shows the dispersion state of the wax of this example.

[0199]

[Table 4]

In the toners TM-1 to TM-3, 5, and 6,
The wax showed a rod-like dispersion state. However, TM-4
In Table 2, the wax was finely dispersed, but showed a granular dispersion state.

Table 5 shows the molecular weight characteristics of the toner after the kneading treatment in this example. The toner was evaluated with a magenta toner. Similar results are obtained with yellow, cyan, and black toners.

[0202]

[Table 5]

Table 6 shows the results of storage stability, OHP translucency, and hot offset start temperature.

[0204]

[Table 6]

The gloss and OHP transmissivity of the image were both high, and hot offset did not occur at least up to 190 ° C. without applying oil.

A copy test was performed using these toners of TM-1 to TM-3, and the copied image was evaluated.

When an image was formed using the toner manufactured as described above by using such an electrophotographic apparatus, the solid black image was uniform without disturbing horizontal lines, scattering of toner, and missing characters. An extremely high-resolution and high-quality image reproducing an image line of / mm was obtained, and a high-density image having an image density of 1.3 or more was obtained. No fogging of the non-image area occurred. Further, even in a long-term durability test of 10,000 sheets, both fluidity and image density showed little change and stable characteristics. In addition, the uniformity of a solid image taken at the time of development was good. There is no development memory. Also, in the transfer, the hollow portion was at a practically acceptable level, and the transfer efficiency was 90%. Further, the filming of the toner on the photoreceptor and the intermediate transfer belt was at a practically acceptable level. No scraping failure occurred during cleaning of the intermediate transfer belt. Further, the toner is not disturbed at the time of fixing and the toner jumping hardly occurs. Further, even in a cleaner process in which the residual toner at the time of transfer is recovered by development without using a cleaning blade, the recovery can be performed smoothly, and the history of the previous image does not remain. Similar results were obtained with TM-5 and 6 toners.

However, in the case of the TM-4 toner, filming occurred on the photoreceptor, the image density was reduced after 5000 sheets had passed, and the image was missing during transfer, resulting in a poor image after printing 10,000 sheets. .

[0209]

As described above, according to the present invention, the wax is dispersed in the binder resin in a linear or rod-like state, so that the toner can be thermally fused even when used in a contact type one-component developing method. It does not cause agglomeration, prevents image density reduction due to overcharging during long-term continuous use, and prevents fog under low temperature and low humidity, has a uniform charge distribution, and outputs stable image characteristics even after long-term use It is possible to continue.

With an electrophotographic method using a conductive elastic roller or an intermediate transfer member, it is possible to prevent dropout or scattering at the time of transfer and obtain high transfer efficiency. Filming of the photoreceptor and the intermediate transfer member can be prevented even in long-term use under high humidity. The cleaning property of the intermediate transfer member can be improved. Even in the cleaning process without using the cleaning blade, the transfer residual toner can be smoothly collected, and the history of the previous image can be prevented from remaining.

Even if oil is not applied with a silicone or fluorine fixing belt, offset properties can be prevented while maintaining high OHP translucency. In addition, even if the belt is used for a long period of time, good non-offset properties can be maintained without causing a belt surface deterioration phenomenon.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view illustrating a configuration of an intermediate transfer belt unit used in an embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating a configuration of a developing unit used in an embodiment of the present invention.

FIG. 4 is a sectional view showing a configuration of a fixing unit used in the embodiment of the present invention.

[Explanation of symbols]

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

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 15/20 102 G03G 9/08 381 15/08 507L F-term (Reference) 2H005 AA01 AA06 AA15 AB02 CA08 CA14 EA03 EA05 EA06 EA10 2H032 AA05 BA05 BA09 2H033 AA09 AA11 BA11 BA12 BA58 2H077 AC04 AD06 AD13 EA14 EA15 FA22

Claims (16)

[Claims] 2. The toner according to claim 1, wherein the toner comprises at least a binder resin, a wax, and a colorant, and the wax is dispersed in the binder resin in a matrix in a linear or rod form. 2. A toner comprising at least a binder resin, a wax and a colorant, wherein the wax is dispersed in a linear or rod-like form in the binder resin, and the arrangement of the adjacent waxes is parallel. A toner characterized by being maintained. 3. The ratio DL / DS between the major axis diameter DL (m) and the minor axis diameter DS (m) of each wax dispersed in the binder resin.
Is the ratio of 1.0 ≦ DL / DS ≦ 2.0 to the total number of waxes, but Q1 is 2.0 <DL / DS ≦
Q2, 5.0 <DL / DS ≦
Q3, 10.0 <DL / D
Assuming that the ratio of S is Q4, the following formula (Equation 1)
The toner according to claim 1, wherein: (Equation 1) 4. A wax having a minor axis diameter DS of 5 in a binder resin.
The toner according to claim 1, wherein the toner particle size is from × 10 ^{−8 to} 3 × 10 ⁻⁷ (m). 5. The long axis diameter DL (m) of the wax in the binder resin, wherein the volume average particle diameter of the toner is DT (m), wherein DT / DL> 4. 5. The toner according to any one of items 1 to 4. 6. The wax has an acid value of 30 to 60 mg KOH.
/ G, melting point 90-120 ° C, penetration at 25 ° C is 2
The toner according to any one of claims 1 to 5, wherein the toner is a hydrocarbon wax having the following ester bond or amide bond. 7. The method according to claim 6, wherein the ester bond of the hydrocarbon wax is obtained by a reaction of a long-chain alkyl alcohol having 5 to 62 carbon atoms, an unsaturated polycarboxylic acid or an anhydride thereof. toner. 8. The wax comprises at least one or more of carnauba wax, candelilla wax, hydrogenated jojoba oil, rice wax, hydrogenated lanolin, medofoam oil, beeswax, ceresin wax or derivatives thereof. 2. The method according to claim 1, wherein
6. The toner according to any one of items 1 to 5. 9. The toner has a volume average particle size of 4 to 9 × 10 ^−6.
The toner according to any one of claims 1 to 5, wherein (m). 10. The binder resin has a weight average molecular weight Mwf of 10,000 to 400,000, a weight average molecular weight Mwf and a number average molecular weight M.
When the ratio Mwf / Mnf of nf is Wmf, Wmf is 3
-100, when the ratio Mzf / Mnf between the Z-average molecular weight Mzf and the number-average molecular weight Mnf is Wzf, Wzf is 10-2.
000, a polyester resin obtained by polycondensation of a polyhydric carboxylic acid or a lower alkyl ester thereof and a polyhydric alcohol having a melting temperature of 80 to 150 ° C. by a 1/2 method using a Koka flow tester. The toner according to claim 1. 11. The binder resin has a weight average molecular weight Mwf of 10,000 to 400,000, a weight average molecular weight Mwf and a number average molecular weight M.
When the ratio Mwf / Mnf of nf is Wmf, Wmf is 3
-100, when the ratio Mzf / Mnf between the Z-average molecular weight Mzf and the number-average molecular weight Mnf is Wzf, Wzf is 10-2.
000, a polyester resin obtained by polycondensation of a polyhydric carboxylic acid or a lower alkyl ester thereof having a melting temperature of 80 to 150 ° C. by a 1/2 method using a Koka flow tester and a polyhydric alcohol. Weight average molecular weight Mwv of created toner
Is 8,000 to 300,000, and when the ratio Mwv / Mnv of the weight average molecular weight Mwv to the number average molecular weight Mnv is Wmv, Wmv
v is 2 to 100, Z average molecular weight Mzv and number average molecular weight M
When the ratio Mzv / Mnv of nv is Wzv, Wzv is 8
Mwf / Mwv is 1.2 to 10, and Wmf / Wmv is 1.
2-10, Wzf / Wzv is 2.2-30.
6. The toner according to any one of 1 to 5. 12. An electrostatic latent image on the image carrier is made visible by inserting a transfer material between the image carrier and the conductive elastic roller and applying a transfer bias voltage to the conductive elastic roller. The toner according to any one of claims 1 to 11, wherein the toner is used in an electrophotographic apparatus including a toner transfer unit that transfers an imaged toner. 13. A developing roller made of a silicone resin or a urethane resin rotatably supported by a shaft and in contact with a photoreceptor, said toner is developed by a supply roller made of a urethane resin rotatably supported and in contact with said developing roller. An electrophotographic apparatus having a contact-type non-magnetic one-component means for supplying to a roller, forming a toner layer by contacting a doctor blade on the developing roll, and contacting the developing roller with a photoreceptor to perform development. The toner according to claim 1, wherein the toner is used. 14. A developing step of visualizing an electrostatic latent image formed on an image carrier with a toner, and contacting the surface of an endless intermediate transfer member with the image carrier to form the intermediate transfer member. A primary transfer process of transferring the toner image to the surface is repeatedly performed a plurality of times, and thereafter,
An electrophotography system having a transfer system configured to execute a secondary transfer process of collectively transferring an overlap transfer toner image formed on the surface of the intermediate transfer body to a transfer material by repeatedly executing the primary transfer process a plurality of times. 12. The toner according to claim 1, wherein the toner is used in a method. 15. An image bearing member comprising at least rotating image carriers and developing means having toners of different colors.
A plurality of movable image forming units for forming toner images of different colors on the image carrier, an image forming position including a single exposure position and a single transfer position, and the plurality of images An image forming unit group in which forming units are arranged in an annular shape, and moving means for rotating and moving the entire image forming unit group to sequentially move each of the plurality of image forming units to the single image forming position, Exposure means for generating signal light, and a mirror for guiding the light of the exposure means to the exposure position substantially at the center of rotation of the image forming unit group, so that toner images of different colors are formed on a transfer material. ,
4. The method according to claim 1, wherein the color image forming apparatus is used for a color electrophotographic apparatus for forming a color image by transferring the images in a superposed manner.
12. The toner according to any one of 11. 16. Recording of toner using a heat-resistant belt having a heat-resistant and deformable surface layer having a surface layer made of any of silicone rubber, fluorine rubber and fluorine resin, a fixing roller, a pressure roller, and a heating member. The toner according to any one of claims 1 to 11, wherein the toner is used in an electrophotographic apparatus provided with a fixing system for fixing on a material by the action of heat and pressure.