JP2010211229A - Fixing device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixing device that prevents a toner from melting out of the fixing device and prevents staining in an image, and to provide an image forming apparatus using the fixing device, and a toner used for the fixing device. <P>SOLUTION: The fixing device 25 for fixing a toner image on a recording medium, by applying heat and/or pressure includes a fixing roller 251, a pressing roller 252, and a cleaning roller 257 to clean one of the above rollers, wherein the cleaning roller 257 is coated with a reactive material that increases the viscoelasticity of a binder resin of the toner. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fixing device and an image forming apparatus using toner used as a developer for fixing an electrostatic charge image in electrophotography, electrostatic recording, electrostatic printing, and the like. More specifically, an electrophotographic toner, an electrophotographic fixing device, and an electrophotographic image forming apparatus used for image formation by an electrostatic copying process such as a copying machine, a facsimile, and a laser printer using a direct or indirect electrophotographic developing system. In addition, electrophotographic dry toner, electrophotographic fixing device, and electrophotographic image forming apparatus used in full-color copiers, full-color facsimiles, full-color laser printers using a direct or indirect electrophotographic multicolor developing system It is about.

In image formation in the electrophotographic method, a pressure heating method using a heating roller is a method in which a toner is passed through a recording medium while contacting the surface of the heating roller having releasability with the toner and the toner image surface of the recording medium under pressure. The image is fixed. In this method, since the surface of the heating roller and the toner image on the recording medium come into contact with each other under pressure, the thermal efficiency at the time of fusing the toner image on the recording medium is extremely good, and the fixing can be performed quickly. it can.
However, since the surface of the heating roller and the toner image are in contact with each other under a molten state and pressure, a part of the toner image adheres to and is transferred to the surface of the fixing roller, which is transferred again to the next recording medium, and the recording medium is soiled. A so-called offset phenomenon occurs. This offset phenomenon is strongly influenced by the fixing speed and fixing temperature.
Generally, when the fixing speed is slow, the surface temperature of the heating roller is set to be relatively high. This is to make the amount of heat applied from the heating roller to the toner to fix the toner substantially constant regardless of the fixing speed.
In this electrophotographic image formation, particularly color image formation, since the toner on the recording medium forms a toner layer in which a plurality of toners overlap, the fixing speed is particularly fast and the surface temperature of the heating roller is high. In this case, the temperature difference between the toner layer in contact with the heating roller and the lowermost toner layer in contact with the recording medium increases. In this case, since the heating roller having a high temperature comes into contact with the uppermost toner, a hot offset phenomenon is likely to occur. Conversely, in order to prevent this hot offset phenomenon, when the temperature of the heating roller is set low, the toner in the lowermost layer is not sufficiently melted, so that the toner is not fixed on the recording medium and is referred to as a cold offset that adheres to the heating roller. A phenomenon occurs.

In order to solve these problems, when the fixing speed is high, the pressure at the time of fixing is increased to use the anchor effect of the toner to the recording medium. In this case, the temperature of the heating roller can be lowered to some extent, and hot offset of the uppermost toner can be prevented. However, since the shearing force applied to the toner becomes very large, the recording medium is wound around the fixing roller, so that the recording medium is jammed or the separation claw is separated to separate the recording medium from the fixing roller. Traces may appear on the fixed image. Further, since the pressure is high, there is a problem that an image with a thin line is crushed at the time of fixing, or toner is scattered to reduce the image quality of the fixed image.
As for the toner, when the fixing speed is high, a toner having a lower melt viscosity near the fixing temperature is used than when the fixing speed is low. However, by lowering the surface temperature of the heating roller and lowering the fixing pressure, the toner image is fixed while preventing hot offset and wrapping jam, and such a low melting viscosity toner is fixed at a low fixing speed. When used in an image forming apparatus, there is a problem that hot offset tends to occur.
However, in recent years, there has been a demand for a toner having a wide fixing temperature range that can be applied from a case where the fixing speed is high to a case where the fixing speed is low and that is excellent in offset resistance.

  On the other hand, in recent years, a high-quality image with excellent reproducibility of fine lines has been demanded. In response to this demand, the toner particle size has been reduced and the resolution and sharpness of the image have been increased. On the other hand, the fixability of the halftone portion formed with the small particle size toner has been reduced. This is particularly remarkable when the fixing speed is high. This is because the amount of toner adhering to the halftone part is small, and the toner transferred to the concave part of the recording medium has a small amount of heat applied from the heating roller, and the fixing pressure is also suppressed by the convex part of the recording medium. To be lower. Further, since the toner transferred to the convex portion of the recording medium in the halftone portion has a thin toner layer, the shearing force per toner becomes larger than that of the solid black portion having a high toner layer thickness, and the offset is reduced. It tends to occur and tends to be a low-quality fixed image.

In order to achieve both toner fixing properties and anti-offset properties, binder resins have been studied up to now as a toner. In Patent Document 1, it is a chromatograph measured by gel permeation chromatography (GPC) of a resin for toner, and at least 1 in each of a region having a molecular weight of 10 ^{3 to} 7 × 10 ^{4 and} a region having a molecular weight of 10 ⁵ to 2 × 10 ^6. Resin molecular weight distributions having more than one maximum are disclosed.
Patent Documents 2 and 3 disclose that a fixing agent and offset resistance are both achieved by introducing a release agent such as polyethylene while regulating the molecular weight of the vinyl copolymer. Patent Document 4 discloses a technique for improving low-temperature fixing and hot offset by a combination of a low-viscosity resin and a high-viscosity resin.
In addition, Patent Documents 5 to 8 disclose techniques for broadening the molecular weight distribution of the binder resin to balance the contradictory storage stability, fixability, and hot offset.

On the other hand, conventionally, in an electrophotographic image forming apparatus, a pressure roller such as a pressure roller is pressed against a heating roller such as a heating roller having a heat source therein, and the recording is performed through a recording medium after image transfer between them. The apparatus mainly includes a fixing device that fixes a toner image on the recording medium while conveying the medium.
In this type of fixing device, a so-called offset phenomenon may occur in which the toner on the recording medium adheres to the heating roller. It is known that when such an offset occurs, the offset toner adheres to the pressure roller, and the recording medium is soiled by reverse transfer from the heating roller and the pressure roller to the recording medium. In order to prevent such an offset, in the conventional fixing device, for example, the surface of the heating roller is coated with fluorine. However, it is difficult to completely prevent the offset depending on the environmental conditions and the type of the recording medium.
Therefore, some conventional fixing devices are provided with a cleaning member such as a cleaning roller in contact with the heating roller or the pressure roller to remove the toner adhering to the heating roller or the pressure roller. That is, there is a technique that removes toner from the difference in surface releasability by pressing a cleaning member made of a solid metal material against a heating roller or pressure roller having improved surface releasability.

By the way, in recent years, in order to prevent wasteful consumption of energy, the image forming apparatus stops energization to the heat source during standby, and energizes the heat source only when image formation starts to raise the heating roller to the fixing temperature. It is getting warmer. For this reason, it is necessary for the heating roller to improve the temperature responsiveness. For example, in the case of a heating roller, the wall thickness is 1 mm or less, and the temperature raising time to the fixing temperature is shortened to about 10 seconds.
In such an image forming apparatus, since the heat capacity of the heating roller is small, the heat transfer to the recording medium at the time of fixing, the heat transfer to the member in contact with the heating roller, the flow of air around the heating roller, etc. There is a problem that the temperature distribution of the heating roller tends to be uneven in the width direction. It has been impossible to make the temperature distribution uniform over the entire area of the heating roller in terms of space and cost.
If the temperature distribution of the heating roller becomes non-uniform in the width direction, the fixing performance becomes unstable, and offsets are likely to occur, and the life of the heating roller tends to be shortened due to thermal degradation. In particular, Patent Document 9 and Patent Document 11 have a problem that when a polymerized toner manufactured by a polymerization method is used, a toner lump that adheres and accumulates on the cleaning member is remelted and reversely transferred to a recording medium. This is because when a pulverized toner manufactured by a pulverization method is used, a toner having a high storage elastic modulus and hardly dissolves adheres to the cleaning member, but when a polymerized toner manufactured by a polymerization method is used, the storage elastic modulus is low. This is because ordinary toner adheres to the cleaning member.
This problem is particularly noticeable when a small-sized recording medium is passed compared to the maximum size that can be passed. This is because, in the case of a small size, since the sheet passing area is small and the area in contact with the heating roller is small, the temperature falls only in the narrow area, and the temperature detection means corresponding to that part supports the lighting of the heat source. This is because the temperature rises unnecessarily to the temperature of the paper passing area, and the toner on the cleaning member corresponding to the non-paper passing area melts and reversely transfers.
Therefore, for example, in Patent Document 12, in order to solve such a problem of reverse transfer, in a conventional fixing device, in order to make the temperature distribution of the heating roller uniform in the width direction, the heating roller is exposed to wind. What prevents the temperature of the non-sheet-passing region from excessively rising is disclosed.
Further, for example, as described in Patent Document 13, there is an air vent that is provided along the cleaning roller to circulate the air in the fixing device as the cleaning roller rotates, thereby preventing the temperature of the cleaning roller from rising.

Japanese Patent Laid-Open No. 5-107803 Japanese Patent Laid-Open No. 5-289399 JP-A-5-313413 JP-A-5-297630 Japanese Patent Laid-Open No. 5-053722 JP-A-6-027733 JP-A-6-074426 JP-A-6-118702 JP-A-11-33665 JP-A-11-149180 JP 2000-292981 A Japanese Patent Laid-Open No. 9-325550 JP 2002-123119 A

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and a problem thereof is a fixing device that prevents toner from melting from the fixing device and prevents image smearing, and an image forming apparatus using the same. And a toner used for the same.
It is another object of the present invention to provide a fixing device, an image forming apparatus, and a toner used in the fixing device in which the toner attached to the cleaning member is not reversely transferred without lowering the fixing efficiency.
Furthermore, an object of the present invention is to provide a fixing device, an image forming apparatus, and a toner used therefor, which can obtain a high-density and high-definition image.

The features of the present invention, which is a means for solving the above problems, are listed below.
The fixing device of the present invention is a fixing device that fixes at least a toner having a binder resin and a colorant on a recording medium with heat and / or pressure, and includes a fixing roller, a pressure roller, and any one of these. And a cleaning member for cleaning the roller, and the cleaning member is coated with a reactive substance that increases the viscoelasticity of the binder resin.
The fixing device of the present invention is a fixing device that fixes at least a toner having a binder resin and a colorant on a recording medium with heat and / or pressure, and a fixing belt stretched between a plurality of rollers and pressurization. It has a roller and a cleaning member for cleaning any one of these rollers and / or a fixing belt, and the cleaning member is coated with a reactive substance that increases the viscoelasticity of the binder resin. And
The fixing device according to the present invention is further characterized in that the reactive substance is a metal compound.
In addition, the fixing device of the present invention further includes supply means for supplying a reactive substance to the cleaning member.
The fixing device of the present invention is further characterized in that the supply means is a supply roller.
The fixing device of the present invention is further characterized in that the cleaning member has a 10-point average roughness Rz of 3 to 50 μm in the surface.

The fixing device according to the present invention is further characterized in that the toner contains a release agent.
In the fixing device of the present invention, the toner further includes a charge control agent.
In the fixing device of the present invention, the toner further has an acid group parameter (mgKOH / g / Mw) of a component soluble in the organic solvent THF of 0.3 × 10 ^{−3 to} 5.0 × 10 ^−3. It is characterized by being in the range.
The fixing device of the present invention is further characterized in that the toner has a weight average molecular weight Mw of a component soluble in an organic solvent THF in the range of 5,000 to 30,000.
The fixing device of the present invention is further characterized in that the toner has an acid value of a component soluble in an organic solvent THF in the range of 2.0 to 50.0 mgKOH / g.
The fixing device of the present invention is further characterized in that the toner has an average circularity of 0.94 or more.

In the fixing device of the present invention, the toner further comprises at least a polymer, polyester, and colorant each having a site capable of reacting with a compound having an active hydrogen group dissolved or dispersed in an organic solvent. The toner composition is obtained by dispersing in a water-based medium and extending and / or crosslinking.
In the fixing device of the present invention, the toner further has a volume average particle diameter of 3.0 to 8.0 μm, and a ratio (Dv / Dv) of the volume average particle diameter (Dv) to the number average particle diameter (Dn). Dn) is in the range of 1.00 to 1.40.
The fixing device of the present invention is further characterized in that the toner has a shape factor SF-1 in the range of 100 to 180 and a shape factor SF-2 in the range of 100 to 180.
In the fixing device of the present invention, the toner has a spindle shape, and the spindle shape is defined by a major axis r1, a minor axis r2, and a thickness r3 (provided that r1 ≧ r2 ≧ r3). ), The ratio of the major axis r1 to the minor axis r2 (r2 / r1) is in the range of 0.5 to 1.0, and the ratio of the thickness r3 to the minor axis r2 (r3 / r2) is 0.7 to It is characterized by being in the range of 1.0.

The image forming apparatus of the present invention includes an image carrier that carries a latent image, a charging device that uniformly charges the surface of the image carrier, and the surface of the charged image carrier that is exposed based on image data, and electrostatically charged. An exposure device that writes a latent image, a developing device that supplies toner to the electrostatic latent image formed on the surface of the image carrier and visualizes the image, and a transfer that transfers the visible image on the surface of the image carrier to a recording member An image forming apparatus comprising: an apparatus; a cleaning device that cleans untransferred residual toner on an image carrier; and a fixing device that fixes a visible image on a recording member with heat and pressure. An apparatus is used.
The image forming apparatus of the present invention further includes an detachable process cartridge that integrally supports the image carrier and at least one device selected from at least a charging device, a developing device, and a cleaning device. Features.

According to the present invention, in the fixing device and the image forming apparatus of the present invention, the toner offset by the fixing device can be collected by the cleaning member and the melting due to remelting can be prevented.
Further, the toner of the present invention is excellent in developability and transferability, and a high-quality image can be obtained.

The best mode for carrying out the present invention will be described below with reference to the drawings. Note that it is easy for a person skilled in the art to make other embodiments by changing or correcting the present invention within the scope of the claims, and these changes and modifications are included in the scope of the claims. The following description is an example of the best mode of the present invention, and does not limit the scope of the claims.
FIG. 1 is a schematic diagram showing a configuration including a heating / pressure roller as an embodiment of the fixing device of the present invention.
In the fixing device 25 of the present invention, as shown in FIG. 1, the fixing roller 251 is formed of, for example, foamed silicone rubber in order to form a nip with the pressure roller 252 on the outer periphery of a metal core such as stainless steel or aluminum. And an elastic layer formed into a ring shape with a heat-resistant elastic material such as liquid silicone rubber. A release layer is provided on the surface layer of the elastic layer in order to improve transfer paper and toner release properties. For the release layer, a material having heat resistance and low surface energy is used. For example, silicone resin, fluororesin, for example, polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), It is used as a heat-resistant tube made of a polymer resin such as tetrafluoroethylene-hexafluoropropylene copolymer (FEP). A heat source such as a halogen heater for accelerating the temperature rise of the fixing roller 251 is disposed in the core of the fixing roller 251.
The pressure roller 252 is provided with an elastic layer made of a heat-resistant elastic material such as fluorine rubber or silicone rubber on the outer periphery of a metal core such as stainless steel or aluminum with an appropriate thickness. A release layer made of fluorine resin or the like is provided. The pressure roller 252 is pressed toward the fixing roller 251 by a pressure member such as a spring (not shown), and pressurizes toner with the fixing roller 251 for a certain period of time by elastically deforming the elastic layer. -Form a nip that can be heated.

  In order to improve the releasability from the toner on the fixing roller 251 and prevent the occurrence of offset, an application roller 255 for applying an oil such as silicone oil for improving the releasability, toner adhered to the fixing roller 251, paper A cleaning roller 256 is provided as a cleaning member for cleaning the powder. In addition, since the toner adheres to the pressure roller 252 from the fixing roller 251 that contacts the pressure roller 252 when not recording paper dust, a cleaning roller 257 is provided on the pressure roller 252. Further, in order to control the heaters of the members in the fixing device 25 such as the fixing roller 251 and the pressure roller 252, a temperature sensor 258 such as a thermistor is provided to detect the temperature of each member.

FIG. 2 is a schematic diagram showing a configuration including a fixing belt as an embodiment of the fixing device of the present invention. The fixing device 26 having the fixing belt includes a heating roller 263, a fixing roller 261, a pressure roller 262 that is in pressure contact with the fixing roller 261, and a fixing belt 264 that is stretched between the heating roller 263 and the fixing roller 261. It has become.
The fixing roller 261 and the pressure roller 262 are provided with an elastic layer made of a heat-resistant elastic material on the outer periphery of a metal cored bar in substantially the same manner as the fixing roller 261 and the pressure roller 262 of the fixing device 26 shown in FIG. . The thickness of the elastic layer is adjusted as appropriate. In addition, a release layer made of a fluorine-based resin or the like is provided on the surface layer of the elastic layer in order to improve the release property of the transfer paper and toner. A halogen heater is disposed inside each of the core bars. Further, the pressure roller 263 is pressed against the fixing roller 261 with a fixing belt 264 interposed therebetween by a pressure member such as a spring (not shown), and is fixed between the fixing roller 261 by deforming the elastic layer. Form a nip where the toner can be pressed and heated for a long time.
The fixing belt 264 is made of an endless belt-like substrate made of heat-resistant resin or metal. Examples of the material of the heat resistant resin include polyimide, polyamideimide, polyether ether ketone, and examples of the material of the metal belt include nickel, aluminum, and stainless steel. A resin and a multilayer may be formed. In particular, a belt obtained by electroforming nickel on a polyimide resin is preferable because it has strength and elasticity and is durable. The thickness is preferably 100 μm or less. Since the fixing belt 264 is in pressure contact with the transfer paper and toner, the fixing belt 264 has an elastic layer made of a highly releasable silicone rubber and a heat-resistant release layer made of a fluorine resin having a small friction coefficient.
The heating roller 263 is a member that stretches the fixing belt 264 that is being stretched and further heats it. For this reason, a heat source such as a halogen lamp or nichrome wire is provided inside the heating roller 263. Further, the heating roller 263 is a thin-walled roller of a hollow metal cylinder such as aluminum, carbon steel, and stainless steel, but by using an aluminum cylinder having a thickness of 1 to 4 mm that has good thermal conductivity, The temperature distribution can be reduced. Further, the surface of the heating roller 263 is subjected to alumite treatment in order to prevent abrasion with the fixing belt 264.
A temperature sensor 265 for detecting the temperature of the outer peripheral surface of the fixing belt 264 is disposed on the outer peripheral surface of the heating roller 263 with the fixing belt 264 interposed therebetween. The operation of the heater inside the heating roller 263 and the like is controlled by a temperature control device (not shown) in accordance with a detection signal from the temperature sensor.

As shown in FIG. 1, in the fixing device 25 of the present invention, the toner on the recording paper receives heat and pressure in the nip between the fixing roller 251 and the pressure roller 252 in the fixing device 25. At this time, the toner is melted by heat, and the viscosity and elasticity are lowered. At the same time, when the pressure is applied, the sheet spreads on the recording paper and enters into the fibers of the recording paper. Next, the recording paper comes out of the nip and moves away from both rollers 251 and 252. The low molecular weight component having a small viscosity contained in the toner melts and easily penetrates between the fibers of the recording paper. At the same time, since the elasticity is low, it is easy to separate and adhere to the fixing roller 251. Further, the high molecular weight component is large in both viscoelasticity, but when it melts and becomes so viscous that the adhesion force to the fixing roller 251 becomes larger than the elasticity, the recording paper is transferred to the fixing roller 251. When the fixing roller 251 rotates and contacts the recording paper again, the transferred toner may adhere to the recording paper and stain the image. However, the fixing roller 251 is provided with a cleaning roller 257 or the like so as not to stain the image, or the fixing roller 251 is coated with silicone oil or contains a release agent in the toner. Prevents toner from remaining. However, it is difficult to completely prevent the remaining part.
Some of the toner may be transferred from the fixing roller 251 to the pressure roller 252 having a low temperature. When the pressure roller 252 rotates and contacts the recording paper again, the toner transferred to the pressure roller 252 may adhere to the back surface of the recording paper and stain the image. In order to prevent this, the pressure roller 252 is provided with a pressure roller cleaning roller (hereinafter simply referred to as “cleaning roller”) 257. The toner transferred from the fixing roller 251 is collected by the cleaning roller 257. However, the toner collected by the cleaning roller 257 is remelted by receiving heat when the fixing device 25 is operated, and is transferred to the pressure roller 252 when the toner melts from the cleaning roller 257, and the recording paper is recorded at the nip portion. May stain the back side. In particular, the low molecular weight component in the binder resin of the toner is easily changed in viscoelasticity by heating, so that offset is likely to occur, and it is easy to remelt and dissolve.

  The toner attached to the pressure roller 252 is collected by the cleaning roller 257 at the nip portion between the pressure roller 252 and the cleaning roller 257. The toner adhering to the fixing roller 251 in such a flow is collected by the cleaning roller 257, and about several g of toner is collected by the cleaning roller 257 after 150,000 printing. Since the conventional toner uses a resin having a relatively high Tg of about 60 ° C., the viscosity of the toner adhering to the cleaning roller 257 is high. Therefore, the fixing device 25 and the cleaning roller 257 have different viscosity depending on the number of prints. Even when the temperature was high, the toner was difficult to dissolve. However, when a low molecular weight resin that melts at a relatively low temperature is used, it melts at a temperature lower than the fixing set temperature. For this reason, if the toner adhering to the cleaning roller 257 does not pass the recording paper and the temperature-controlled fixing device 25 is rotated, the toner collected on the cleaning roller 257 is melted and the pressure roller 252 or the fixing roller. 251 again. In this state, if an image is output and the recording paper is passed through, it will melt and stain the recording paper.

In the fixing device 25 of the present invention, the cleaning roller 257 is coated with a reactive substance that increases the viscoelasticity of the binder resin. As a reactive substance that increases viscoelasticity, there is a substance that increases the molecular weight by a crosslinking or elongation reaction with a binder resin. A substance that increases viscoelasticity by reacting with a functional group having polarity in the binder resin and crosslinking is preferable. Here, the substance to be cross-linked is different from amines and ketones used for cross-linking or elongation of monomers in a solvent.
Examples of the substance that increases the viscoelasticity include metal compounds, specifically, metal salts of naphthenic acid or higher fatty acids, azo metal complexes, salicylic acid metal salts, or metal complexes such as zinc, chromium, iron, and zirconium. In addition, a chelate compound selected from silicon, zirconium, and aluminum, or a metal alcoholate thereof may be used. By coating these onto the cleaning roller 257, the toner transferred to the cleaning roller 257 is cross-linked and viscoelasticity is increased, thereby preventing re-melting from the cleaning roller 257 and recording paper or the like. It can prevent contamination.

  Further, the fixing device of the present invention includes a supply unit 258 that supplies a reactive substance to the cleaning roller 257. The supply means 258 is preferably a supply roller 258 provided on the pressure roller 252. The supply roller 258 has a brush made of resin fibers, rotates and rubs the reactive material molded body 260 to scrape the brush 259, and causes the reactive material to adhere to the pressure roller 252. At this time, the toner transferred from the heating roller to the pressure roller 252 causes the reactive substance to adhere to the surface, and is collected by the cleaning roller 257 when the toner reaches the cleaning roller 257. The toner collected on the cleaning roller 257 reacts with the reactive substance to crosslink and increase the viscoelasticity and firmly adhere to the cleaning roller 257. After that, even if the temperature rises, the viscoelasticity increases, and it does not melt and reattach to the pressure roller 252 to stain the recording paper or the like.

Further, in the fixing device 25 of the present invention, the cleaning roller 257 is made of a metal such as SUS, copper such as brass, or aluminum, and uses a rod-like roller having a diameter of 10 to 30 mm. Further, the surface of the cleaning roller 257 is in the range of 3 to 50 μm in terms of ten-point average roughness Rz (hereinafter simply referred to as “roughness Rz”). The surface roughness Rz can be formed by blasting such as shot blasting, sand blasting, or liquid honing, and sand blasting that is easy to process is particularly preferable.
Here, the diameter of the cleaning roller 257 is set within a range in which the cleaning roller 257 can be disposed in the fixing device 25. If the cleaning roller 257 is too large, the rise of the fixing device 25 is delayed, which is not preferable. However, when the cleaning roller 257 is large, the surface area is increased correspondingly, and the amount of toner that can be collected by the cleaning roller 257 increases. Further, the thickness of the toner wound around the cleaning roller 257 per unit recovery amount of the cleaning roller 257 is reduced, the change in the toner thickness amount due to the number of printed sheets is small, and the mechanical pressure and thermal force on the pressure roller 252 are reduced. The amount of change is small and the stability of the fixing device is excellent. Conversely, when the diameter of the cleaning roller 257 is small, the thickness of the wrapping toner varies depending on the number of prints, so that the mechanical pressure and thermal variation with respect to the pressure roller 252 are large. May be put out. Further, by setting the surface of the cleaning roller 257 to a predetermined roughness Rz, the application property of the reactive substance can be made uniform. When the roughness Rz is small, dripping occurs after coating, and when the roughness Rz is large, the presence of the reactive substance can be coarse and dense. Here, although a single cleaning roller 257 has been described, a plurality of pressure rollers 252 may be provided. Further, the cleaning roller 257 may be provided together with the fixing roller 251 or alone.

  The toner used in the fixing device of the present invention includes production methods such as a pulverization method and a polymerization method (suspension polymerization, emulsion polymerization dispersion polymerization, emulsion aggregation, emulsion association, etc.), but is not limited to these production methods. As an example of the pulverization method, first, the above-mentioned resin, pigment or dye as a colorant, charge control agent, release agent, other additives, etc. are sufficiently mixed by a mixer such as a Henschel mixer, and then batch type. The constituent materials are well kneaded using a two-roll, Banbury mixer, continuous twin-screw extruder, continuous single-screw kneader, or the like, and cut after rolling and cooling. The toner kneaded product after cutting is crushed, coarsely pulverized using a hammer mill, etc., and further pulverized by a fine pulverizer or mechanical pulverizer using a jet stream, and a classifier or Coanda effect using a swirling airflow Is classified to a predetermined particle size by a classifier using Thereafter, inorganic fine particles are externally added by a mixer and mixed to obtain a toner. Moreover, an example of the polymerization method is shown. It is preferable to use a toner in which a toner composition containing at least a polymer having an active hydrogen group, polyester, a colorant, and a release agent is crosslinked and / or extended in the presence of resin fine particles in an aqueous medium.

  The toner used in the fixing device of the present invention contains wax as a release agent. It becomes clear that the presence of wax in the toner greatly affects the releasability of the toner at the time of fixing, and the wax is finely dispersed in the toner and exists in the toner in the vicinity of the surface. Thus, good fixing releasability can be obtained. In particular, it is preferable that the wax has a long diameter and is dispersed to 1 μm or less. In this way, the release agent is contained in the toner, and the release agent is contained in the toner, so that the toner offset to the fixing roller 251 can be reduced, and the toner collected by the cleaning roller 257 of the pressure roller can be reduced. Can be reduced.

  Known waxes can be used, and include polyolefin waxes (polyethylene wax, polypropylene wax, etc.); long chain hydrocarbons (paraffin wax, sazol wax, etc.); carbonyl group-containing waxes, and the like. Of these, carbonyl group-containing waxes are preferred. Carbonyl group-containing waxes include polyalkanoic acid esters (carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18. -Octadecanediol distearate, etc.); polyalkanol esters (trimellitic acid tristearyl, distearyl maleate, etc.); polyalkanoic acid amides (ethylenediamine dibehenyl amide, etc.); polyalkylamides (trimellitic acid tristearyl amide, etc.) And dialkyl ketones (such as distearyl ketone). Among these carbonyl group-containing waxes, polyalkanoic acid esters are preferred. The melting point of the wax of the present invention is usually 40 to 160 ° C, preferably 50 to 120 ° C, more preferably 60 to 90 ° C. A wax having a melting point of less than 40 ° C. has an adverse effect on heat resistant storage stability, and a wax having a melting point of more than 160 ° C. tends to cause a cold offset when fixing at a low temperature. Further, the melt viscosity of the wax is preferably 5 to 1000 cps, more preferably 10 to 100 cps as a measured value at a temperature 20 ° C. higher than the melting point. Waxes exceeding 1000 cps have poor effects for improving hot offset resistance and low-temperature fixability. The content of the wax in the toner is usually 0 to 40% by weight, preferably 3 to 30% by weight.

The toner used in the fixing device of the present invention contains a charge control agent. In particular, a high charge amount can be imparted by fixing the charge control substance to the surface of the toner. That is, by fixing to the surface of the toner, the amount and state of presence on the toner surface are stabilized, and the charge amount can be stabilized. In particular, in the toner having the configuration of the present invention, the charge amount stability is increased.
Examples of charge control agents include nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), Examples thereof include alkylamides, phosphorus simple substances or compounds, tungsten simple substances or compounds, fluorine-based activators, salicylic acid metal salts and metal salts of salicylic acid derivatives.
The amount of charge control agent used is determined by the type of binder resin, the presence or absence of additives used as necessary, and the toner production method including the dispersion method, and is not uniquely limited. Preferably, it is used in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, the effect of the main charge control agent is reduced, the electrostatic attractive force with the developing roller is increased, the flowability of the developer is reduced, and the image density is reduced. Incurs a decline. These charge control agents and release agents can be melt-kneaded together with the masterbatch and resin, and of course, they may be added when dissolved and dispersed in an organic solvent.

The toner used in the fixing device of the present invention has an acid group parameter (mgKOH / g / Mw) of a component soluble in the organic solvent THF in the range of 0.3 × 10 ^{−3 to} 5.0 × 10 ⁻³ . It is in. The low molecular weight binder resin has a lower softening point, a lower elastic modulus TG ', and a lower viscosity coefficient Tη at a lower temperature than a high molecular weight binder resin. For this reason, the fixing temperature can be lowered. However, at the same time, it tends to be offset to a fixing member such as a fixing roller, and the binder resin collected by the cleaning roller is likely to be melted, and the back surface of the transfer paper may be soiled. Therefore, in order to react with the metal compound on the cleaning roller and increase the weight average molecular weight after being collected on the cleaning roller, the acid group parameter (mgKOH / g / Mw) of the component soluble in the organic solvent THF is 0. The range is 3 × 10 ^{−3 to} 5.0 × 10 ⁻³ . This acid group parameter is an index indicating the abundance ratio of the site that reacts with the metal compound with respect to the weight average molecular weight Mw. By making this acid group parameter (mgKOH / g / Mw) in the range of 0.3 × 10 ^{−3 to} 5.0 × 10 ⁻³ , a component soluble in the organic solvent THF in the binder resin in the cleaning roller When the molecular weight is increased, the elastic modulus TG ′ is increased, and the viscosity coefficient Tη is increased, so that melting from the cleaning roller can be prevented. If this acid group parameter (mgKOH / g / Mw) exceeds 5.0 × 10 ⁻³ , the weight average molecular weight cannot be increased to the extent that it reacts with the metal compound to prevent dissolution. When the acid group parameter (mgKOH / g / Mw) is less than 0.3 × 10 ⁻³ , the contact probability between the reaction point of the component soluble in the organic solvent and the reaction point of the metal compound becomes diffusion-limited, and on the cleaning roller The recovery rate of the binder resin recovered in this way is higher, and the reaction does not proceed so much as to prevent dissolution. If the outermost surface of the binder resin collected on the cleaning roller has no opportunity to react with the metal compound, it is considered that the reactive substance coated on the cleaning roller does not substantially act.

In the toner used in the fixing device of the present invention, the weight average molecular weight Mw of the component soluble in the organic solvent THF is in the range of 5,000 to 30,000. In order to maintain heat-resistant storage stability while having low-temperature fixability and hot offset resistance, it is important to adjust the weight average molecular weight (Mw) of the binder resin. It is preferable to design the Mw of the THF soluble part of 5,000 to 30,000. If the Mw is less than 5,000, the oligomer component increases, so even if the chemical structure is controlled as described above, the heat resistant storage stability is deteriorated. It is to do.
The molecular weight is measured by GPC (gel permeation chromatography) as follows. Stabilize the column in a heat chamber at 40 ° C., flow THF at a flow rate of 1 ml / min through the column at this temperature, and prepare a THF sample solution of the resin prepared to a sample concentration of 0.05 to 0.6% by weight. 50 to 200 μL is injected and measured. In measuring the molecular weight of the sample, the molecular weight distribution of the sample was calculated from the relationship between the logarithmic value of the prepared calibration curve and the count using several types of monodisperse polystyrene standard samples. As a standard polystyrene sample for preparing a calibration curve, for example, Pressure Chemical
Co. Or molecular weight made by Toyo Soda Industry Co., Ltd. is 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10 ⁵ , 3.9. ^{× 10 5, 8.6 × 10 5} , 2 × 10 6, used as a 4.48 × 10 ^6, it is appropriate to use at least about 10 standard polystyrene samples. An RI (refractive index) detector is used as the detector.

In addition, by setting the acid value of the binder resin to 2.0 to 50.0 mgKOH / g, the toner characteristics such as low-temperature fixability, hot offset resistance, heat-resistant storage stability, and charging stability can be improved. Is possible. The toner of the present invention can be produced by mixing, as a binder resin, a polymer having a site capable of reacting with a compound having an active hydrogen group, which will be described in detail later (hereinafter referred to as “prepolymer”). . By mixing this prepolymer with a compound having an active hydrogen group, an elongation or a crosslinking reaction can be carried out in the toner production process, and the toner characteristics can be improved. Here, when the acid value of the binder resin exceeds 50.0 mgKOH / g, the prepolymer elongation or crosslinking reaction becomes insufficient, and the hot offset resistance is affected. , The prepolymer elongation or cross-linking reaction is likely to proceed, causing problems in production stability.
In addition, the measuring method of the acid value of binder resin is based on the method based on JISK0070. However, when the sample does not dissolve, a solvent such as dioxane or THF is used as the solvent.

  The toner used in the fixing device of the present invention has an average circularity of 0.94 or more. When the average circularity of the toner is 0.94 or more, the dot reproducibility is excellent and the transferability is also good, so that high image quality can be obtained. When the average circularity is less than 0.94 and the toner is in a shape away from the spherical shape, it is difficult to obtain a high-quality image with sufficient transferability or no dust. The circularity of the toner is a value obtained by optically detecting particles and dividing by the circumference of an equivalent circle having the same projected area. Specifically, the measurement is performed using a flow type particle image analyzer (FPIA-2000; manufactured by Sysmex Corporation). In a predetermined container, 100 to 150 mL of water from which impure solids are removed in advance is added, 0.1 to 0.5 mL of a surfactant is added as a dispersant, and about 0.1 to 9.5 g of a measurement sample is further added. The suspension in which the sample is dispersed is subjected to dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the concentration and dispersion of the dispersion are set to 3,000 to 10,000 / μL, and the shape and distribution of the toner are measured.

The toner has a volume average particle size of 3.0 to 8.0 μm and a ratio (Dv / Dn) of the volume average particle size (Dv) to the number average particle size (Dn) of 1.00 to 1.40. It is in the range. By using a toner having such a particle size and particle size distribution, it is excellent in all of heat-resistant storage stability, low-temperature fixability, and hot offset resistance, and particularly when used in a full-color image forming apparatus, it has excellent gloss. Sex is obtained. In general, it is said that the smaller the particle size of the toner, the more advantageous it is to obtain a high-resolution and high-quality image, but it is disadvantageous for transferability and cleaning properties. is there. Also, when the volume average particle size is smaller than the above range, in the case of a two-component developer, the toner is fused to the surface of the magnetic carrier during a long period of stirring in the developing device, and the charging ability of the magnetic carrier is lowered. When used as an agent, toner filming on the developing roller and toner fusion to a member such as a blade for thinning the toner are likely to occur. Conversely, when the volume average particle diameter of the toner is larger than the above range, it becomes difficult to obtain a high-resolution and high-quality image, and the toner in the developer is balanced. In many cases, the variation in the particle size of the particles increases.
On the other hand, if Dv / Dn exceeds 1.40, the charge amount distribution becomes wide and the resolving power decreases, which is not preferable. The average particle size and particle size distribution of the toner can be measured using a Coulter Counter TA-II and Coulter Multisizer II (both manufactured by Coulter). In the present invention, a Coulter counter TA-II type was used and connected to an interface (manufactured by Nikka Giken) for outputting the number distribution and volume distribution and a PC 9801 personal computer (manufactured by NEC).

The toner has a shape factor SF-1 in the range of 100 to 180, and a shape factor SF-2 in the range of 100 to 180.
FIG. 3 is a diagram schematically illustrating the shape of the toner in order to explain the shape factor SF-1 and the shape factor SF-2.
The shape factor SF-1 indicates the ratio of the roundness of the toner shape and is represented by the following formula (1). This is a value obtained by dividing the square of the maximum length MXLNG of the shape formed by projecting toner on a two-dimensional plane by the figure area AREA and multiplying by 100π / 4.
SF-1 = {(MXLNG) ² / AREA} × (100π / 4) (1)
If the toner shape factor SF-1 is a value close to 100, the shape of the toner is close to a sphere, and the contact between the toner and the toner, or the contact between the toner and the photoconductor is a point contact. Accordingly, the fluidity is increased and the adhesion between the toner and the photoreceptor is also weakened, and the transfer rate is increased. On the other hand, if the value of the shape factor SF-1 is greater than 180, the shape factor SF-1 becomes indefinite, which is not preferable because developability and transferability deteriorate.

The shape factor SF-2 indicates the ratio of unevenness in the shape of the toner, and is represented by the following formula (2). A value obtained by dividing the square of the perimeter PERI of the figure formed by projecting the toner onto the two-dimensional plane by the figure area AREA and multiplying by 100 / 4π.
SF-2 = {(PERI) ² / AREA} × (100 / 4π) (2)
As the value of SF-2 is closer to 100, the toner surface has less unevenness and becomes smoother. In order to improve the cleaning property, it is preferable that the surface has moderate irregularities, but when the shape factor SF-2 is larger than 180, the irregularities become conspicuous, so that the toner is scattered on the image and the image quality is improved. Is not preferable.
Specifically, the shape factor is measured by taking a photograph of the toner with a scanning electron microscope (S-800: manufactured by Hitachi, Ltd.), and introducing it into an image analyzer (LUSEX 3: manufactured by Nireco) for analysis. And calculated.

  The toner used in the fixing device of the present invention has a substantially spherical shape and can be expressed by the following shape rule. FIG. 4 is a diagram schematically showing the shape of the toner according to the present invention. In (a), when a substantially spherical toner is defined by a major axis r1, a minor axis r2, and a thickness r3 (where r1 ≧ r2 ≧ r3), the toner of the present invention has a major axis and a minor axis. (R2 / r1) (see (b)) is 0.5 to 1.0, and the ratio of thickness to short axis (r3 / r2) (see (c)) is 0.7 to 1.0. It is preferable that it exists in the range. When the ratio of the major axis to the minor axis (r2 / r1) is less than 0.5, the dot reproducibility and transfer efficiency are inferior because of being away from the true spherical shape, and high-quality image quality cannot be obtained. On the other hand, if the ratio of thickness to minor axis (r3 / r2) is less than 0.7, the shape is close to a flat shape, and a high transfer rate like a spherical toner cannot be obtained. In particular, when the ratio of the thickness to the minor axis (r3 / r2) is 1.0, the rotating body has a major axis as a rotation axis, the toner fluidity can be improved, the transfer rate is high, and the image is faithful. A high-quality image can be obtained because of the transfer. In addition, since the mixing with the magnetic carrier is good, the charge amount distribution can be narrowed, and high-accuracy image reproduction is possible. Note that r1, r2, and r3 were measured with a scanning electron microscope (SEM) while changing the angle of field of view and taking pictures.

  The toner used in the fixing device of the present invention includes a toner composition in which at least a polymer having a site capable of reacting with a compound having an active hydrogen group, polyester, and a colorant is dispersed in an organic solvent. Those which are dispersed in a medium and subjected to elongation and / or crosslinking reaction are preferred. In the following, the constituent materials and manufacturing method of the toner will be described. Here, constituent materials and production examples of the toner by the wet polymerization method will be described, but the toner of the present invention may be a dry melt kneading method.

(Modified polyester)
The polyester resin contains a functional group contained in the acid or alcohol monomer unit and a bonding group other than an ester bond, or a resin component having a different structure in the polyester resin is bonded by a covalent bond or an ionic bond. .
For example, the polyester terminal is reacted with something other than an ester bond. Specifically, a functional group such as an isocyanate group that reacts with an acid group or a hydroxyl group is introduced at the terminal and further reacted with an active hydrogen compound to modify or extend the terminal. Further, compounds having a plurality of active hydrogen groups include those in which polyester ends are bonded to each other (urea-modified polyester, urethane-modified polyester, etc.). In addition, a reactive group such as a double bond is introduced into the polyester main chain, radical polymerization is caused therefrom, and a carbon-carbon bond graft component is introduced into the side chain or the double bonds are bridged. Included (styrene modified, acrylic modified polyester, etc.).
In addition, a resin component having a different structure is copolymerized in the polyester main chain or reacted with a terminal carboxyl group or hydroxyl group. For example, those having a terminal copolymerized with a silicone resin modified with a carboxyl group, a hydroxyl group, an epoxy group, or a mercapto group are included (silicone-modified polyester and the like).

(Synthesis example of modified polyester)
724 parts of bisphenol A ethylene oxide 2-mole adduct, 200 parts of isophthalic acid and 70 parts of fumaric acid, and 2 parts of dibutyltin oxide were placed in a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, at 230 ° C. at normal pressure. The reaction was continued for 8 hours at a reduced pressure of 10 to 15 mmHg, followed by cooling to 160 ° C., and 32 parts of phthalic anhydride was added thereto and reacted for 2 hours. Next, the mixture was cooled to 80 ° C., 200 parts of styrene, 1 part of benzoyl peroxide and 0.5 part of dimethylaniline were added in ethyl acetate, and the reaction was performed for 2 hours. Polystyrene graft-modified polyester (1) was obtained.
Examples of the urea-modified polyester (i) include a reaction product of a polyester prepolymer (A) having an isocyanate group and an amine (B). Examples of the polyester prepolymer (A) having an isocyanate group include a product obtained by further reacting a polyester having an active hydrogen group with a polyisocyanate (3), which is a polycondensate of polyol (1) and polycarboxylic acid (2). Can be mentioned. Examples of the active hydrogen group possessed by the polyester include hydroxyl groups (alcoholic hydroxyl groups and phenolic hydroxyl groups), amino groups, carboxyl groups, mercapto groups, and the like. Among these, alcoholic hydroxyl groups are preferred.

  Examples of the polyol (1) include a diol (1-1) and a tri- or higher valent polyol (1-2). (1-1) alone or (1-1) and a small amount of (1-2) Mixtures are preferred. Diol (1-1) includes alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycol (diethylene glycol) , Triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol) F, bisphenol S, etc.); alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the above alicyclic diol; Examples include adducts of alkylene oxides (ethylene oxide, propylene oxide, butylene oxide, etc.) of enols. Among them, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use. The trihydric or higher polyol (1-2) includes 3 to 8 or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (Trisphenol PA, phenol novolak, cresol novolak, etc.); and alkylene oxide adducts of the above trivalent or higher polyphenols.

Examples of the polycarboxylic acid (2) include dicarboxylic acid (2-1) and trivalent or higher polycarboxylic acid (2-2). (2-1) alone and (2-1) with a small amount of ( The mixture of 2-2) is preferable. Dicarboxylic acid (2-1) includes alkylene dicarboxylic acid (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acid (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acid (phthalic acid, isophthalic acid, terephthalic acid) And naphthalenedicarboxylic acid). Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms. Examples of the trivalent or higher polycarboxylic acid (2-2) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (trimellitic acid, pyromellitic acid, and the like). In addition, as polycarboxylic acid (2), you may make it react with polyol (1) using the acid anhydride or lower alkyl ester (methyl ester, ethyl ester, isopropyl ester, etc.) of the above-mentioned thing.
The ratio of the polyol (1) and the polycarboxylic acid (2) is usually 2/1 to 1/1, preferably 1. as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. 5/1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.
Examples of the polyisocyanate (3) include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.); aromatic Diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanurates; polyisocyanates such as phenol derivatives, oximes, caprolactam And a combination of two or more of these.

  The ratio of the polyisocyanate (3) is usually 5/1 to 1/1, preferably 4 /, as the equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. 1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5, low-temperature fixability deteriorates. If the molar ratio of [NCO] is less than 1, the urea content in the modified polyester will be low, and the hot offset resistance will deteriorate. The content of the polyisocyanate (3) component in the prepolymer (A) having an isocyanate group at the terminal is usually 0.5 to 40% by weight, preferably 1 to 30% by weight, more preferably 2 to 20% by weight. It is. If it is less than 0.5% by weight, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40% by weight, the low-temperature fixability deteriorates.

The number of isocyanate groups contained per molecule in the prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2.5 on average. It is. If it is less than 1 per molecule, the molecular weight of the modified polyester will be low, and the hot offset resistance will deteriorate.
As amines (B), diamine (B1), trivalent or higher polyamine (B2), aminoalcohol (B3), aminomercaptan (B4), amino acid (B5), and amino acids B1-B5 blocked (B6) etc. are mentioned. Examples of the diamine (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′dimethyldicyclohexylmethane, diaminecyclohexane, Isophorone diamine etc.); and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine etc.) and the like. Examples of the trivalent or higher polyamine (B2) include diethylenetriamine and triethylenetetramine. Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid. Examples of the B1 to B5 amino group blocked (B6) include ketimine compounds and oxazoline compounds obtained from the B1 to B5 amines and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). Among these amines (B), preferred are B1 and a mixture of B1 and a small amount of B2.

Furthermore, if necessary, the molecular weight of the modified polyester can be adjusted using an elongation terminator. Examples of the elongation terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).
The ratio of amines (B) is the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the prepolymer (A) having isocyanate groups and amino groups [NHx] in amines (B). The ratio is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2. When [NCO] / [NHx] exceeds 2 or less than 1/2, the molecular weight of the urea-modified polyester (i) becomes low and the hot offset resistance deteriorates. In the present invention, the modified polyester (i) may contain a urethane bond together with a urea bond. The molar ratio of the urea bond content to the urethane bond content is usually 100/0 to 10/90, preferably 80/20 to 20/80, and more preferably 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance is deteriorated.

The main peak molecular weight of the modified polyester of the present invention is usually 1000 to 10000, preferably 2000 to 8000. When the amount of the component having a molecular weight of less than 1000 is increased, the heat resistant storage stability tends to be deteriorated, and when the component having a molecular weight of 10,000 or more is increased, the low-temperature fixability is simply decreased, but the decrease can be suppressed as much as possible by balance control. Further, the content of a polymer component having a molecular weight of 30,000 or more is 1% to 10%, and preferably 3 to 6%, although it varies depending on the toner material. If it is less than 1%, sufficient hot offset resistance cannot be obtained, and if it is 10% or more, the glossiness and transparency may be deteriorated.
Moreover, it leads to hot offset improvement by using the polyester resin which contains 1-25% of THF insolubles. In addition, due to long-term agitation inside the one-component developing device, the toner is further pulverized by contact stress caused by the developing roller, toner supply roller, layer thickness regulating blade, friction charging blade, etc., and fine particles are generated or fluidized. Since the agent is embedded in the toner surface, it has an effect on the problem of image quality degradation. The THF-insoluble matter is effective for hot offset in color toners, but it has a negative effect on glossiness and transparency of OHP, but it is effective within 1 to 10% to widen the mold release width. There is a case to do.

(Unmodified polyester)
In the present invention, not only the modified polyester (i) is used alone, but also the unmodified polyester (ii) can be contained as a toner binder component together with the (i). By using (ii) in combination, the low-temperature fixability and the gloss when used in a full-color device are improved, which is preferable to single use. Examples of (ii) include the same polycondensates of polyol (1) and polycarboxylic acid (2) as in the polyester component (i) above, and preferred ones are also the same as (i). Further, (ii) is not limited to unmodified polyester, but may be modified with, for example, a urea bond or a urethane bond. It is preferable that (i) and (ii) are at least partially compatible with each other in terms of low-temperature fixability and hot offset resistance. Accordingly, the polyester component (i) and (ii) preferably have similar compositions. When (ii) is contained, the weight ratio of (i) and (ii) is usually 5/95 to 80/20, preferably 5/95 to 30/70, more preferably 5/95 to 25/75, Particularly preferred is 7/93 to 20/80. When the weight ratio of (i) is less than 5%, the hot offset resistance is deteriorated, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.
The peak molecular weight of (ii) is usually 1000-20000, preferably 1500-10000, more preferably 2000-8000. If it is less than 1000, heat-resistant storage stability will deteriorate, and if it exceeds 10,000, low-temperature fixability will deteriorate. The hydroxyl value of (ii) is preferably 5 or more, more preferably 10 to 120, and particularly preferably 20 to 80. If it is less than 5, it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. The acid value of (ii) is preferably 10-30. By giving an acid value, it tends to be negatively charged, and the fixability tends to be further improved. However, when the acid value exceeds 30, particularly when used in a high-temperature and high-humidity environment, the charge amount of the toner is reduced, and problems such as background smearing on the image may occur.

In the present invention, the glass transition point (Tg) of (ii) is 35 to 55 ° C, preferably 40 to 55 ° C. When the temperature is lower than 35 ° C., the heat-resistant storage stability of the toner is deteriorated. Due to the coexistence of the modified polyester resin, the dry toner of the present invention tends to have good heat-resistant storage stability even when the glass transition point is low, as compared with known polyester toners. As the storage elastic modulus of the toner binder, the temperature (TG ′) at which 10000 dyne / cm ² is obtained at a measurement frequency of 20 Hz is usually 100 ° C. or higher, preferably 110 to 200 ° C. If it is less than 100 ° C., the resistance to hot offset deteriorates. As the viscosity of the toner binder, the temperature (Tη) at 1000 poise at a measurement frequency of 20 Hz is usually 180 ° C. or lower, preferably 90 to 160 ° C. If it exceeds 180 ° C., the low-temperature fixability deteriorates. That is, from the viewpoint of achieving both low temperature fixability and hot offset resistance, TG ′ is preferably higher than Tη. In other words, the difference between TG ′ and Tη (TG′−Tη) is preferably 0 ° C. or higher. More preferably, it is 10 degreeC or more, Most preferably, it is 20 degreeC or more. The upper limit of the difference is not particularly limited. Further, from the viewpoint of achieving both heat-resistant storage stability and low-temperature fixability, the difference between Tη and Tg is preferably 0 to 100 ° C. More preferably, it is 10-90 degreeC, Most preferably, it is 20-80 degreeC.

  Here, although a release agent and a charge control agent are used, the above-mentioned known ones can be appropriately selected and used.

(External additive)
As the external additive, inorganic fine particles can be preferably used. The primary particle diameter of the inorganic fine particles is preferably 5 mμ to 2 μm, and particularly preferably 5 mμ to 500 mμ. Moreover, it is preferable that the specific surface area by BET method is 20-500 m < ² > / g. The proportion of the inorganic fine particles used is preferably 0.01 to 5% by weight of the toner, and particularly preferably 0.01 to 2.0% by weight. Specific examples of the inorganic fine particles include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, quartz sand, clay, mica, wollastonite, diatomaceous earth. Examples include soil, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride.
In addition, polymer fine particles, such as polystyrene obtained by soap-free emulsion polymerization, suspension polymerization, and dispersion polymerization, methacrylate esters, acrylate copolymers, polycondensation systems such as silicone, benzoguanamine, and nylon, thermosetting Examples thereof include polymer particles made of a resin.
Such external additives can be surface treated to increase hydrophobicity and prevent deterioration of flow characteristics and charging characteristics even under high humidity. For example, silane coupling agents, silylating agents, silane coupling agents having an alkyl fluoride group, organic titanate coupling agents, aluminum coupling agents, silicone oils, modified silicone oils and the like are preferable surface treatment agents. .
Further, as a cleaning property improver for removing the developer after transfer remaining on the photosensitive member or the primary transfer medium, for example, fatty acid metal salts such as zinc stearate and calcium stearate, such as polymethyl methacrylate fine particles, polystyrene fine particles, etc. Examples thereof include fine polymer particles produced by soap-free emulsion polymerization. The polymer fine particles preferably have a relatively narrow particle size distribution and a volume average particle size of 0.01 to 1 μm.

(Coloring agent)
As the colorant of the present invention, all known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide , Ocher, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa Yellow (GR, A, RN, R), Pigment Yellow L, Benzidine Yellow (G, GR), Permanent Yellow (NCG), Vulcan Fast Yellow ( 5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red , Fais red, parachlorol Nitroaniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine B, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Tolujing Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake , Thioindigo red B, thioindigo maroon, oil red, quinacridone red, pyrazolone , Polyazo red, chrome vermillion, benzidine orange, perinone orange, oil orange, cobalt blue, cerulean blue, alkali blue rake, peacock blue rake, Victoria blue rake, metal free phthalocyanine blue, phthalocyanine blue, fast sky blue, in Dunslen Blue (RS, BC), Indigo, Ultramarine Blue, Bitumen, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Chrome Oxide, Pyridian, Emerald Green, Pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake Phthalocyanine green, anthraquinone green, titanium oxide, zinc white, lithobon and mixtures thereof can be used. The content of the colorant is usually 1 to 15% by weight, preferably 3 to 10% by weight, based on the toner.

The colorant used in the present invention can also be used as a master batch combined with a resin. As the binder resin to be kneaded together with the production of the masterbatch or the masterbatch, in addition to the modified and unmodified polyester resins mentioned above, styrene such as polystyrene, poly p-chlorostyrene, polyvinyltoluene, and polymers of substituted products thereof; Styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer Styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α- Chloromethyl methacrylate copolymer, Tylene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid Styrene copolymers such as acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, poly Acrylic resin, rosin, modified rosin, terpene resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax, etc. can be used alone or in combination. The
This master batch can be obtained by mixing and kneading a resin for a master batch and a colorant under a high shear force to obtain a master batch. At this time, an organic solvent can be used to enhance the interaction between the colorant and the resin. Also, a so-called flushing method called watering paste containing water of colorant is mixed and kneaded with resin and organic solvent, and the colorant is transferred to the resin side to remove moisture and organic solvent components. Since it can be used as it is, it does not need to be dried and is preferably used. For mixing and kneading, a high shear dispersion device such as a three-roll mill is preferably used.

The dry toner of the present invention can be produced by the following method, but is not limited thereto.
(Production method of toner in aqueous medium)
As an aqueous medium used in the present invention, water alone may be used, but a solvent miscible with water may be used in combination. Examples of the miscible solvent include alcohol (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methylcellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.) and the like.
As a method for stably forming a dispersion composed of the prepolymer (A) and the unmodified polyester (ii) in the aqueous medium, the prepolymer (A) and the unmodified polyester (ii) are formed in the aqueous medium. Examples thereof include a method of adding a toner raw material composition and dispersing it by shearing force. Prepolymer (A), unmodified polyester (ii) and other toner compositions (hereinafter referred to as toner raw materials), a colorant, a colorant masterbatch, a release agent, a charge control agent, etc. are contained in an aqueous medium. Although mixing may be performed when forming the dispersion, it is more preferable to mix the toner raw materials in advance and then add and disperse the mixture in the aqueous medium. In the present invention, other toner materials such as a colorant, a release agent, and a charge control agent do not necessarily have to be mixed when forming particles in an aqueous medium, but after the particles are formed. , May be added. For example, after forming particles containing no colorant, the colorant can be added by a known dyeing method.

The dispersion method is not particularly limited, and known equipment such as a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, and an ultrasonic wave can be applied. In order to make the particle size of the dispersion 2 to 20 μm, a high-speed shearing type is preferable. When a high-speed shearing disperser is used, the rotational speed is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 5 minutes. The temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 40 to 98 ° C. Higher temperatures are preferred in that the dispersion made of the modified polyester (i) or the prepolymer (A) has a low viscosity and is easily dispersed.
The amount of the aqueous medium used relative to 100 parts of the toner composition containing the prepolymer (A) and the unmodified polyester (ii) is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight. If the amount is less than 50 parts by weight, the dispersion state of the toner composition is poor, and toner particles having a predetermined particle diameter cannot be obtained. If it exceeds 20000 parts by weight, it is not economical. Moreover, a dispersing agent can also be used with resin fine particles as needed. It is preferable to use a dispersant because the particle size distribution becomes sharp and the dispersion is stable.
The step of synthesizing the urea-modified polyester from the prepolymer (A) may be carried out by adding amines (B) before dispersing the toner composition in the aqueous medium, or after dispersing in the aqueous medium, the amines. (B) may be added to cause a reaction from the particle interface. In this case, urea-modified polyester is preferentially produced on the surface of the toner to be produced, and a concentration gradient can be provided inside the particles.

  Anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates and phosphates, alkylamines as dispersants for emulsifying and dispersing the oily phase in which the toner composition is dispersed in a liquid containing water Amine salts such as salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, imidazoline, alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, pyridinium salts, alkylisoquinolinium salts, benzethonium chloride, etc. Nonionic surfactants such as quaternary ammonium salt type cationic surfactants, fatty acid amide derivatives, polyhydric alcohol derivatives, such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-alkyl N, amphoteric surfactants such as N- dimethyl ammonium betaine.

Further, by using a surfactant having a fluoroalkyl group, the effect can be obtained in a very small amount. Preferred anionic surfactants having a fluoroalkyl group include fluoroalkyl carboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [omega-fluoroalkyl (C6-C11 ) Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [omega-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) carvone Acids and metal salts, perfluoroalkylcarboxylic acids (C7 to C13) and metal salts thereof, perfluoroalkyl (C4 to C12) sulfonic acids and metal salts thereof, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- ( 2-hydroxyethyl) -Fluorooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, etc. Is mentioned.
Product names include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS-101. DS-102 (manufactured by Taikin Kogyo Co., Ltd.), Mega-Fac F-ll0, F-120, F-113, F-191, F-812, F-833 (Dainippon Ink Co., Ltd.), Xtop EF- 102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fagento F-100, F150 (manufactured by Neos).

  Examples of cationic surfactants include aliphatic primary, secondary or secondary amine acids having fluoroalkyl groups, aliphatic quaternary ammonium salts such as perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salts, and benzas. Luconium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names include Surflon S-121 (Asahi Glass), Florard FC-135 (Sumitomo 3M), Unidyne DS-202 (Daikin Industries) , Megafac F-150, F-824 (Dainippon Ink Co., Ltd.), Xtop EF-132 (Tochem Products Co., Ltd.), Footgent F-300 (Neos Co., Ltd.), and the like.

Moreover, tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, hydroxyapatite, etc. can be used as an inorganic compound dispersant which is hardly soluble in water.
Further, it is particularly preferable to stabilize the dispersed droplets with a polymeric protective colloid. For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride and other (meth) acrylic monomers containing hydroxyl groups Bodies such as β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, γ-hydroxypropyl acrylate, γ-hydroxypropyl methacrylate, 3-acrylate Chloro-2-hydroxypropyl, 3-chloro-2-hydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate, N -Methylol acrylamide, N-methylol methacrylamide, etc., vinyl alcohol or ethers with vinyl alcohol, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, etc., or esters of compounds containing vinyl alcohol and carboxyl groups, such as Vinyl acetate, vinyl propionate, vinyl butyrate, acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, vinyl pyridine, vinyl pyrrolidone, vinyl imidazole, ethylene imine, etc. Homopolymers or copolymers such as those having a nitrogen atom or a heterocyclic ring thereof, polyoxyethylene, polyoxypropylene, Oxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxyethylene nonyl phenyl ester Polyoxyethylenes such as, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used.
In addition, when an acid such as calcium phosphate salt or an alkali-soluble substance is used as the dispersion stabilizer, the calcium phosphate salt is removed from the fine particles by a method such as dissolving the calcium phosphate salt with an acid such as hydrochloric acid and washing with water. To do. It can also be removed by operations such as enzymatic degradation.
When a dispersant is used, the dispersant may remain on the surface of the toner particles. However, it is preferable from the charged surface of the toner that the dispersant is washed and removed after the elongation and / or crosslinking reaction.

Further, in order to lower the viscosity of the toner composition, a solvent in which the prepolymer (A) and the unmodified polyester (ii) are soluble can be used. The use of a solvent is preferable in that the particle size distribution becomes sharp. The solvent is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal. Examples of the solvent include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, Methyl ethyl ketone, methyl isobutyl ketone and the like can be used alone or in combination of two or more. In particular, aromatic solvents such as toluene and xylene and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform, and carbon tetrachloride are preferable. The usage-amount of the solvent with respect to 100 parts of prepolymers (A) is 0-300 parts normally, Preferably it is 0-100 parts, More preferably, it is 25-70 parts. When a solvent is used, it is removed by heating under normal pressure or reduced pressure after the elongation and / or crosslinking reaction.
The elongation and / or crosslinking reaction time is selected depending on the reactivity of the isocyanate group structure of the prepolymer (A) and the amines (B), but is usually 10 minutes to 40 hours, preferably 2 to 24 hours. is there. The reaction temperature is usually 0 to 150 ° C, preferably 5 to 50 ° C. Moreover, a well-known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.

In order to remove the organic solvent from the obtained emulsified dispersion, a method can be employed in which the temperature of the entire system is gradually raised and the organic solvent in the droplets is completely evaporated and removed. Alternatively, it is also possible to spray the emulsified dispersion in a dry atmosphere to completely remove the water-insoluble organic solvent in the droplets to form toner fine particles, and to evaporate and remove the aqueous dispersant together. . As a dry atmosphere in which the emulsified dispersion is sprayed, a gas obtained by heating air, nitrogen, carbon dioxide gas, combustion gas, or the like, in particular, various air streams heated to a temperature equal to or higher than the boiling point of the highest boiling solvent used are generally used. Sufficient quality can be obtained with a short treatment such as spray dryer, belt dryer or rotary kiln.
When the particle size distribution at the time of emulsification dispersion is wide, and washing and drying processes are performed while maintaining the particle size distribution, the particle size distribution can be adjusted by classification into a desired particle size distribution.
In the classification operation, the fine particle portion can be removed in the liquid by a cyclone, a decanter, centrifugation, or the like. Of course, the classification operation may be performed after obtaining the powder as a powder after drying.
The dispersant used is preferably removed from the obtained dispersion as much as possible, but it is preferable to carry out it simultaneously with the classification operation described above.

By mixing the resulting dried toner powder with dissimilar particles such as release agent fine particles, charge control fine particles, fluidizing agent fine particles, and colorant fine particles, or by giving mechanical impact force to the mixed powder By immobilizing and fusing on the surface, it is possible to prevent detachment of the foreign particles from the surface of the resulting composite particle.
Specific means include a method of applying an impact force to the mixture by blades rotating at high speed, a method of injecting and accelerating the mixture in a high-speed air stream, and causing particles or composite particles to collide with an appropriate collision plate, etc. is there. As equipment, Ong mill (manufactured by Hosokawa Micron Co., Ltd.), I-type mill (manufactured by Nippon Pneumatic Co., Ltd.) has been modified to reduce the pulverization air pressure, hybridization system (manufactured by Nara Machinery Co., Ltd.), kryptron System (manufactured by Kawasaki Heavy Industries, Ltd.), automatic mortar, etc.

  The toner can be mixed with a magnetic carrier and used as a two-component developer. In this case, the carrier to toner content ratio in the developer is preferably 1 to 10 parts by weight of toner with respect to 100 parts by weight of carrier. As the magnetic carrier, conventionally known ones such as iron powder, ferrite powder, magnetite powder, magnetic resin carrier having a particle diameter of about 20 to 200 μm can be used. Examples of the coating material include amino resins such as urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, and epoxy resin. Polyvinyl and polyvinylidene resins such as acrylic resins, polymethyl methacrylate resins, polyacrylonitrile resins, polyvinyl acetate resins, polyvinyl alcohol resins, polyvinyl butyral resins, polystyrene resins and styrene acrylic copolymer resins, Halogenated olefin resins such as vinyl, polyester resins such as polyethylene terephthalate resin and polybutylene terephthalate resin, polycarbonate resins, polyethylene resins, polyvinyl fluoride resins, polyvinylidene fluoride resins, polytrifluoroethylene resins, polyhexafluoro Propylene resin, copolymer of vinylidene fluoride and acrylic monomer, copolymer of vinylidene fluoride and vinyl fluoride, tetrafluoroethylene and vinylidene fluoride and non- Monomers including a fluoro terpolymers such, and silicone resins. Moreover, you may contain electrically conductive powder etc. in coating resin as needed. As the conductive powder, metal powder, carbon black, titanium oxide, tin oxide, zinc oxide or the like can be used. These conductive powders preferably have an average particle diameter of 1 μm or less. When the average particle diameter is larger than 1 μm, it becomes difficult to control electric resistance.

  The toner of the present invention can also be used as a one-component magnetic toner that does not use a carrier or a non-magnetic toner.

  In addition, when preparing the developer, in order to improve the fluidity, storage stability, developability, and transferability of the developer, the hydrophobic silica fine particles listed above are further listed in the developer produced as described above. Inorganic fine particles such as powder may be added and mixed. For mixing external additives, a general powder mixer is used, but it is preferable to equip a jacket or the like to adjust the internal temperature. In order to change the load history applied to the external additive, the external additive may be added in the middle or gradually. Of course, you may change the rotation speed of a mixer, rolling speed, time, temperature, etc. A strong load may be given first, then a relatively weak load, and vice versa. Examples of the mixing equipment that can be used include a V-type mixer, a rocking mixer, a Ladige mixer, a Nauter mixer, a Henschel mixer, and the like.

An image forming apparatus using the toner of the present invention as a developer will be described.
FIG. 5 is a schematic diagram showing a configuration of an embodiment of the image forming apparatus according to the present invention. In the figure, reference numeral 100 is a copying apparatus main body, 200 is a paper feed table on which the copying apparatus is placed, 300 is a scanner mounted on the copying apparatus main body 100, and 400 is an automatic document feeder (ADF) mounted thereon.
The copying apparatus main body 100 has a tandem type in which four image forming units 18 each having various units for performing an electrophotographic process such as charging, developing, and cleaning are arranged in parallel around a photosensitive member 40 as a latent image carrier. An image forming apparatus 20 is provided. Above the tandem type image forming apparatus 20, there is provided an exposure apparatus 21 that exposes the photoreceptor 40 with laser light based on image information to form a latent image. Further, an intermediate transfer belt 10 made of an endless belt member is provided at a position facing each photoconductor 40 of the tandem type image forming apparatus 20. A primary transfer unit 62 for transferring the toner images of the respective colors formed on the photoconductor 40 to the intermediate transfer belt 10 is disposed at a position facing the photoconductor 40 via the intermediate transfer belt 10.
A secondary transfer device 22 that collectively transfers the toner images superimposed on the intermediate transfer belt 10 onto transfer paper conveyed from the paper feed table 200 is disposed below the intermediate transfer belt 10. The secondary transfer device 22 is configured by spanning a secondary transfer belt 24 that is an endless belt between two rollers 23, and is disposed by pressing against the support roller 16 via the intermediate transfer belt 10. The toner image on 10 is transferred onto a transfer sheet. A fixing device 25 for fixing the image on the transfer paper is provided beside the secondary transfer device 22. The fixing device 25 is configured by pressing a pressure roller 252 against a fixing belt 254 which is an endless belt.
The secondary transfer device 22 described above also has a sheet transport function for transporting the transfer paper after image transfer to the fixing device 25. Of course, a transfer roller or a non-contact charger may be arranged as the secondary transfer device 22, and in such a case, it is difficult to provide this sheet conveyance function together.
In the illustrated example, a reversing device 28 for reversing the transfer paper so as to record images on both sides of the transfer paper is provided below the secondary transfer device 22 and the fixing device 25 in parallel with the tandem image forming device 20 described above. .

  The developing device 4 of the image forming unit 18 uses a developer containing the above toner. In the developing device 4, the developer carrying member carries and conveys the developer, and an alternating electric field is applied at a position facing the photoconductor 40 to develop the latent image on the photoconductor 40. By applying the alternating electric field, the developer is activated, the charge amount distribution of the toner can be narrowed, and the developability can be improved.

  In addition, the photosensitive member 40 and the developing device are integrally supported, and the process cartridge can be formed to be detachable from the main body of the image forming apparatus. In addition, the process cartridge may include a charging unit and a cleaning unit.

The operation of the image forming apparatus is as follows.
First, a document is set on the document table 30 of the automatic document feeder 400, or the automatic document feeder 400 is opened and a document is set on the contact glass 32 of the scanner 300, and the automatic document feeder 400 is closed. Hold it down.
When a start switch (not shown) is pressed, when the document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 32, and then the document is set on the other contact glass 32. At that time, the scanner 300 is immediately driven, and the first traveling body 33 and the second traveling body 34 travel. Then, the first traveling body 33 emits light from the light source and further reflects the reflected light from the document surface toward the second traveling body 34 and reflects by the mirror of the second traveling body 34 and passes through the imaging lens 35. The document is placed in the reading sensor 36 and the original content is read.

  When a start switch (not shown) is pressed, one of the support rollers 14, 15, 16 is rotated by a drive motor (not shown), the other two support rollers are driven to rotate, and the intermediate transfer belt 10 is rotated and conveyed. To do. At the same time, the individual image forming means 18 rotates the photoconductor 40 to form black, yellow, magenta, and cyan monochrome images on each photoconductor 40. Then, along with the conveyance of the intermediate transfer belt 10, these single color images are sequentially transferred to form a composite color image on the intermediate transfer belt 10.

On the other hand, when a start switch (not shown) is pressed, one of the paper feed rollers 42 of the paper feed table 200 is selectively rotated, the sheet is fed out from one of the paper cassettes 44 provided in the paper bank 43 in multiple stages, and the separation roller 45 Then, the sheets are separated one by one into the paper feed path 46, transported by the transport roller 47, guided to the paper feed path 48 in the copying machine main body 100, and abutted against the registration roller 49 and stopped.
Alternatively, the sheet feed roller 50 is rotated to feed out the sheets on the manual feed tray 51, separated one by one by the separation roller 52, put into the manual feed path 53, and abutted against the registration roller 49 and stopped.
Then, the registration roller 49 is rotated in synchronization with the composite color image on the intermediate transfer belt 10, the sheet is fed between the intermediate transfer belt 10 and the secondary transfer device 22, and is transferred by the secondary transfer device 22. A color image is recorded on the sheet.

The image-transferred sheet is conveyed by the secondary transfer device 22 and sent to the fixing device 25. The fixing device 25 applies heat and pressure to fix the transferred image, and then the switching roller 55 is used to switch the discharge image. The paper is discharged at 56 and stacked on the paper discharge tray 57. Alternatively, it is switched by the switching claw 55 and put into the sheet reversing device 28, where it is reversed and guided again to the transfer position, and an image is recorded also on the back surface, and then discharged onto the discharge tray 57 by the discharge roller 56.
On the other hand, the intermediate transfer belt 10 after the image transfer is removed by the intermediate transfer belt cleaning device 17 to remove residual toner remaining on the intermediate transfer belt 10 after the image transfer, so that the tandem image forming apparatus 20 can prepare for the image formation again.

  EXAMPLES The present invention will be further described below with reference to examples, but the present invention is not limited thereto. In the following description, “parts” and “%” are based on weight unless otherwise specified.

Production Example 1
[Synthesis of Modified Polyester Resin (A-1)]
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 358 parts of bisphenol A ethylene oxide 2-mole adduct, 381 parts of bisphenol A propylene oxide 2-mole adduct, 200 parts of isophthalic acid, 127 parts of terephthalic acid and dibutyl 2 parts of tin oxide was added, reacted at 230 ° C. at normal pressure for 8 hours, and further reacted for 5 hours while dehydrating at a reduced pressure of 10 to 15 mmHg to obtain a polyester prepolymer having a hydroxyl value of 25 and an acid value of 0.9. Further cooled to 80 ° C., 364 parts of ethyl acetate and 98 parts of isophorone diisocyanate were added and reacted at 110 ° C. for 2 hours. Mw 12,000, ethyl acetate of modified polyester resin (A-1) having an NCO content of 1.29% A solution (solid concentration 75%) was obtained.

Production Example 2
[Synthesis of Blocked Amine (B)]
In a reaction vessel equipped with a stir bar and a thermometer, 30 parts of isophoronediamine and 70 parts of methyl ethyl ketone were charged and reacted at 50 ° C. for 5 hours to obtain an amine blocked product (B).

Production Example 3
[Synthesis of low molecular weight polyester]
229 parts of bisphenol A ethylene oxide 2-mole adduct, 529 parts of bisphenol A propylene oxide 3-mole adduct, 208 parts of terephthalic acid, 46 parts of adipic acid and dibutyltin oxide 2 parts was added and reacted at 230 ° C. under normal pressure for 8 hours, and further reacted under reduced pressure of 10 to 15 mmHg for 5 hours. Then, 44 parts of trimellitic anhydride was added to the reaction vessel, and 1. The mixture was reacted for 8 hours to obtain [Low molecular weight polyester 1]. [Low molecular weight polyester 1] had Mn 2,500, Mw 6,700, a peak molecular weight of 5,000, a Tg of 43 ° C., and an acid value of 25.

Production Example 4
[Synthesis of carbon black masterbatch resin]
1,200 parts of water, 540 parts of carbon black (manufactured by Printex35 Dexa) [DBP oil absorption = 42 ml / 100 mg, pH = 9.5], 1,200 parts of low molecular weight polyester resin obtained in Production Example 3 were added and pressurized After mixing with a kneader, the mixture was kneaded at 150 ° C. for 30 minutes using two rolls, rolled and cooled, and pulverized with a pulverizer to obtain a carbon black masterbatch resin.

[Synthesis of toner base particles (1)]
In a beaker, add 100 parts of carbon black masterbatch resin, 50 parts of ethyl acetate solution of carnauba wax (wax concentration 10%) wet-dispersed in a bead mill until the average particle size becomes 0.5 μm, and 70 parts of ethyl acetate. Until dispersed. Further, 20 parts of an ethyl acetate solution of the modified polyester resin (A-1) and 1.2 parts of a blocked amine product (B) are mixed to prepare a resin and colorant preparation solution (1) having a solid content concentration of 50%. Got. To this beaker, 560 parts of water, polymethyl methacrylate fine particle dispersion aqueous solution (manufactured by Kao Corporation: PB-200H), 3.6 parts in terms of solid content, and 3 parts of sodium dodecylnaphthalenesulfonate were added, and then a TK homomixer. (Manufactured by Tokushu Kika) was used and mixed at 25 ° C. for 1 minute at a rotational speed of 12,000 rpm to obtain an emulsion dispersion (X).
100 parts of this emulsified dispersion (X) was transferred to a stainless steel Kolben equipped with a helical ribbon type three-stage stirring blade, and stirred at a rotational speed of 60 rpm, and under reduced pressure (10 kPa) at 25 ° C. for 6 hours in the emulsion. The ethyl acetate was removed from the solvent until the concentration of became 8% to obtain an emulsified dispersion (Y-1).
To this emulsified dispersion (Y-1), 1.9 parts of carboxymethylcellulose (Serogen HH, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was added to increase the viscosity (the time for starting the thickening was 10 hours after the preparation of the emulsified dispersion. ), While stirring at a rotational speed of 300 rpm to give a share, the solvent was removed under reduced pressure (10 kPa) until the ethyl acetate concentration in the emulsion reached 3%, and the rotational speed was further reduced to 60 rpm. Solvent removal was performed until the ethyl acetate concentration reached 1%. The viscosity of the emulsion after thickening was 6,000 mPa · s.
Centrifugation of 100 parts of the emulsified liquid, 60 parts of water was further added to the recovered cake, and the process of centrifugal separation and solid-liquid separation was repeated 5 times, followed by drying at 35 ° C. for 48 hours to form toner base particles (1 )

Next, with respect to 100 parts of toner base particles of the obtained colored powder, 0.4 part of a charge control agent (Bontron X-11 manufactured by Orient Chemical Co., Ltd.) was charged into a Q-type mixer (manufactured by Mitsui Mining Co., Ltd.), and turbine type The peripheral speed of the blades was set to 50 m / sec, the 2-minute operation and the 1-minute pause were performed for 5 cycles, and the total treatment time was 10 minutes.
Further, 0.5 part of hydrophobic silica (H2000, manufactured by Clariant Japan) was added, mixed for 30 seconds at a peripheral speed of 15 m / sec, and subjected to 5 minutes of rest for 1 minute to obtain a black toner.

[Example of carrier production]
100 parts of silicone resin (organostraight silicone)

Toluene 100 parts γ- (2-aminoethyl) aminopropyltrimethoxysilane 5 parts carbon black 10 parts The above mixture was dispersed with a homomixer for 20 minutes to prepare a coating layer forming solution. This coat layer forming liquid was coated on the surface of 1,000 parts of spherical magnetite having a particle diameter of 50 μm using a fluid bed type coating apparatus to obtain a magnetic carrier A.

  4 parts of the toner and 96 parts of magnetic carrier were mixed by a ball mill to prepare a two-component developer 1.

<Example 1>
Using a Ricoh Co., Ltd. imageio NEO451 as a fixing roller, Ricoh's My Recycle 100W paper was set on this and a copy test was conducted. The cleaning roller is made of aluminum and has a diameter of 10 mm and a roughness Rz of 10 μm. On the surface of this cleaning roller, a reactive substance (Bontron X-11 manufactured by Orient), which is a reactive substance that increases viscoelasticity, is dissolved in toluene, and then the dry weight amount per cleaning roller of about 300 mm in the longitudinal direction. As a result, it was applied with a brush so as to be 0.07 g and dried.
(Hot offset evaluation)
With this image forming apparatus, the presence or absence of hot offset due to reverse transfer of molten toner from the cleaning roller to the fixed image was visually evaluated. A4 of the special chart (6% area ratio) was printed on both sides and continuously running. The case where melted-off hot offset was not observed was evaluated as “◯”, the case where it was confirmed was evaluated as “Δ”, and the case where paper was jammed was evaluated as “×”.
<Comparative Example 1>
The same procedure as in Example 1 was performed, except that no reactive substance that increases viscoelasticity was applied to the cleaning roller.

この結果、実施例１では、両面換算で４０，０００枚まで問題がなく「○」で、１４０，０００枚で「△」であった。比較例１では、両面換算で４０，０００枚までで「△」で、６５，０００枚で巻き付きジャムが発生し「×」であった。

As a result, in Example 1, there was no problem up to 40,000 sheets in double-sided conversion, and “◯” was obtained, and 140,000 sheets were “Δ”. In Comparative Example 1, “△” was obtained for 40,000 sheets in terms of double-sided, and “×” was generated when 65,000 sheets were wound.

1 is a schematic diagram illustrating a configuration including a heating / pressure roller as an embodiment of a fixing device of the present invention. 1 is a schematic diagram illustrating a configuration including a fixing belt as an embodiment of a fixing device of the present invention. FIG. 6 is a diagram schematically illustrating the shape of a toner in order to explain the shape factor SF-1 and the shape factor SF-2. FIG. 3 is a diagram schematically illustrating the shape of a toner according to the present invention. 1 is a schematic diagram illustrating a configuration of an embodiment of an image forming apparatus according to the present invention.

4 Developing device 10 Intermediate transfer belt (intermediate transfer member)
18 Image forming means 21 Exposure device 25 Fixing device 251 Fixing roller 252 Pressure roller 255 Application roller 256 Fixing roller cleaning roller 257 Pressure roller cleaning roller 258 Temperature sensor 259 Supply roller 260 Molded body 26 (with fixing belt) Fixing device 261 Fixing roller 262 Pressure roller 263 Heating roller 264 Fixing belt 265 Application roller 266 Fixing roller cleaning roller 267 Pressure roller cleaning roller 268 Temperature sensor 269 Supply roller 270 Molded body 40 Photoconductor (latent image carrier)
22 Secondary transfer device 62 Primary transfer means 100 Copier main body 200 Paper feed table 300 Scanner 400 Automatic document feeder

Claims (18)

In a fixing device for fixing a toner having at least a binder resin and a colorant on a recording medium with heat and / or pressure,
The fixing device includes a fixing roller, a pressure roller, and a cleaning member that cleans any of these rollers, and the cleaning member is coated with a reactive substance that increases the viscoelasticity of the binder resin. A fixing device characterized by that. In a fixing device for fixing a toner having at least a binder resin and a colorant on a recording medium with heat and / or pressure,
The fixing device includes a fixing belt stretched around a plurality of rollers, a pressure roller, and a cleaning member that cleans any of these rollers and / or the fixing belt, and is bonded to the cleaning member. A fixing device that is coated with a reactive substance that increases the viscoelasticity of the resin. The fixing device according to claim 1 or 2,
The fixing device, wherein the reactive substance is a metal compound. The fixing device according to any one of claims 1 to 3,
The fixing device includes supply means for supplying a reactive substance to a cleaning member. The fixing device according to claim 4.
The fixing device, wherein the supply means is a supply roller. The fixing device according to any one of claims 1 to 5,
The cleaning device has a ten-point average roughness Rz of a surface in a range of 3 to 50 μm. The fixing device according to claim 1,
The fixing device, wherein the toner includes a release agent. The fixing device according to any one of claims 1 to 7,
The fixing device, wherein the toner includes a charge control agent. The fixing device according to claim 1,
The toner has an acid group parameter (mgKOH / g / Mw) of a component soluble in an organic solvent THF in the range of 0.3 × 10 ^{−3 to} 5.0 × 10 ^−3. . The fixing device according to claim 9.
The fixing device is characterized in that the toner has a weight average molecular weight Mw of a component soluble in an organic solvent THF in the range of 5,000 to 30,000. The fixing device according to claim 9 or 10, wherein:
The fixing device according to claim 1, wherein the toner has an acid value of a component soluble in an organic solvent THF in a range of 2.0 to 50.0 mgKOH / g. The fixing device according to any one of claims 1 to 11,
The fixing device according to claim 1, wherein the toner has an average circularity of 0.94 or more. The fixing device according to claim 12,
In the toner, a toner composition in which at least a polymer having a site capable of reacting with a compound having an active hydrogen group, polyester, and a colorant is dissolved or dispersed in an organic solvent is dispersed in an aqueous medium. The fixing device is obtained by stretching and / or crosslinking reaction. The fixing device according to any one of claims 7 to 13,
The toner has a volume average particle size of 3.0 to 8.0 μm,
A fixing device having a ratio (Dv / Dn) of a volume average particle diameter (Dv) to a number average particle diameter (Dn) in a range of 1.00 to 1.40. The fixing device according to any one of claims 7 to 14,
The toner has a shape factor SF-1 in the range of 100 to 180 and a shape factor SF-2 in the range of 100 to 180. The fixing device according to any one of claims 7 to 15,
The toner has a spindle shape, and
The spindle shape is defined by a major axis r1, a minor axis r2, and a thickness r3 (where r1 ≧ r2 ≧ r3), and the ratio (r2 / r1) between the major axis r1 and the minor axis r2 is 0.5. A fixing device having a thickness in the range of -1.0 and a ratio of the thickness r3 to the minor axis r2 (r3 / r2) in the range of 0.7-1.0. An image carrier that carries a latent image; a charging device that uniformly charges the surface of the image carrier; an exposure device that exposes the surface of the charged image carrier based on image data and writes an electrostatic latent image; A developing device that supplies toner to the electrostatic latent image formed on the surface of the image carrier to make it visible, a transfer device that transfers the visible image on the surface of the image carrier to a recording member, and an image on the image carrier In an image forming apparatus comprising: a cleaning device that cleans untransferred residual toner; and a fixing device that fixes a visible image on a recording member with heat and / or pressure;
An image forming apparatus using the fixing device according to claim 1. The image forming apparatus according to claim 17.
The image forming apparatus comprises an image carrier, and at least one process cartridge selected from a charging device, a developing device, and a cleaning device, and a removable process cartridge. .

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