JP4978990B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming method such as a copying machine, a printer, and a facsimile using an electrophotographic process, an image forming apparatus, a fixing device, and an electrophotographic toner.

Conventionally, as a fixing method used in the dry development method, a heating heat roller method is widely used because of its energy efficiency. In recent years, in order to save energy by fixing the toner at a low temperature, the thermal energy given to the toner at the time of fixing tends to be small.
(apparatus)
Methods for heat-fixing a toner image on a transfer paper are roughly classified into a contact fixing method and a non-contact fixing method. The former includes heating roller fixing, belt fixing, the latter includes flash fixing, and oven (atmosphere) fixing. The belt fixing method is a heat-efficient fixing method because the toner image and the heating roller are in direct contact and the fixing nip time is long.
The belt fixing device is a fixing device that fixes a toner image on a transfer material by pressing a fixing belt or a fixing roller as a fixing member against the toner image on the transfer material. For example, the fixing device of Patent Document 1 has a belt curvature. A fixing belt with a small thickness that is stretched between a fixing roller and a heating roller that are endlessly moved while being heated by the heating roller, presses the fixing belt against the toner image on the transfer material, and a toner image on the transfer material Is fixed by heating. This fixing belt generally has a three-layer structure including a heat-resistant resin such as polyimide, a metal base, a heat-resistant rubber, an elastic layer made of an elastomer, and a release layer (outermost layer) made of a fluororesin. . The release layer made of the fluororesin is formed by coating a fluororesin tube formed by extrusion molding on the elastic layer, and then heating and melting (hereinafter, fired) the fluororesin. Moreover, after applying fluororesin particles to the elastic layer by spraying or the like, the fluororesin is fired to form a release layer. Thus, by forming the release layer with a fluororesin, a fixing belt having excellent release properties and heat resistance can be obtained.
However, since there is no description about the presence or absence of a resistance adjusting agent such as carbon black in the toner described in Patent Document 1, it is considered that the toner is usually used without adjusting the resistance. It is assumed to be very high. In addition, since the fluororesin is poor in flexibility, if it is stretched between a fixing roller having a small belt curvature and a heating roller and used for a long time, the release layer will crack and obtain sufficient belt durability. I could not.
Various proposals have been made to solve such problems. For example, Patent Document 2 describes a fixing belt in which the release layer is a fluororesin having a melt viscosity (MFR (melt flow rate)) of 3 or less and does not generate cracks even when used for a long time. .
Furthermore, in such a fixing belt, the toner image on the transfer material may be disturbed by the static electricity on the belt surface, or the toner may be offset, and it is a problem to prevent the accumulation of static electricity on the belt surface. For this purpose, it is effective to reduce the surface resistance of the release layer. However, in general, when a conductive filler is dispersed in a fluororesin to reduce the resistance, the bending resistance is lowered and the Use will cause cracks. A low-melting-type fluororesin having a small MFR has a problem in that it cannot achieve both crack resistance and prevention of static electricity accumulation.

(toner)
In terms of low-temperature fixing of toner, use of a polyester resin having excellent low-temperature fixability and relatively good heat storage stability has been tried in place of the conventionally used styrene-acrylic resins. However, for further low-temperature fixing, it is necessary to control the thermal characteristics of the resin itself. However, if the glass transition temperature (Tg) is lowered too much, the heat-resistant storage stability is deteriorated or the molecular weight is decreased. If the softening temperature [T (F1 / 2)] of the resin is lowered too much, there are problems such as lowering the hot offset occurrence temperature. For this reason, even a polyester resin excellent in low-temperature fixability has not yet obtained a toner having excellent low-temperature fixability and high hot offset occurrence temperature by controlling the thermal characteristics of the resin itself.

In order to solve this problem, an attempt to add a specific non-olefinic crystalline polymer having a sharp melt property at a glass transition temperature in a binder resin (see Patent Document 3) or an attempt to use a crystalline polyester ( Patent Documents 4 to 8).
In recent years, with the development of digital copying machines, laser printers, and the like, there is a high demand for higher image quality. Particularly for printers, at present, a high image quality of 300 dpi is the mainstream, but it is expected that the image quality will be further improved to 480 dpi and 600 dpi in the future. Under such circumstances, it is inevitable that the use of a toner having a smaller particle size is required more severely. It is known that when the toner particle size is small, it is difficult to apply pressure to the toner particles even if the pressure is applied between the fixing members, so that the fixability is deteriorated. In particular, in the case of a fixing device having a low surface pressure such as belt fixing, this tendency becomes remarkable. In order to achieve low temperature fixing using the heating belt fixing method, it is necessary to optimize the toner prescription design in consideration of fixing conditions, toner particle size, and melting characteristics in accordance with the characteristics of the fixing method.
In Patent Document 9 (Japanese Patent No. 3310253), since crystalline polyester is contained, there is a tendency that the volume specific resistance value LogR tends to be lower than that of toner not containing crystalline polyester. For toners that tend to increase dirt and toner scattering, it is described that LogR is adjusted to 10.5 to 11.2 LogΩ · cm, particularly preferably 10.7 to 11.15 LogΩ · cm. This technique is not intended to provide an image forming apparatus with a short rise time, capable of fixing a toner having a small particle diameter at a low temperature, and having no abnormal image and excellent in durability. Further, Patent Document 10 (Japanese Patent Application Laid-Open No. 2003-5555) contains an image of a toner that contains a crystalline polyester and therefore tends to have a lower volume resistivity LogR than a toner that does not contain a crystalline polyester. In this fixing device, the surface resistivity is 1 × 1011Ω / □ or less, and 1 × 10 8 to 1 × 10 11Ω / in order to remove static electricity on the belt surface and prevent dust and electrostatic offset of the toner image on the transfer material. In order to avoid the problem of bending resistance being lowered when conductive filler is dispersed in general PFA to reduce resistance, the perfluoroalkyl vinyl ether component is increased and oxygen atoms in the molecular chain are Uses PFA with a number / carbon atom ratio of 1/60 or more to prevent toner image dust and electrostatic offset, and release with good bending resistance This technology also provides an image forming apparatus that has a short rise time, can fix a small particle size toner at a low temperature, has no abnormal image, and has excellent durability. Not meant to be

JP 2002-268436 A JP 2003-167462 A JP 62-63940 A JP 2003-167384 A Japanese Patent No. 2931899 JP 2001-222138 A JP 2004-221740 A JP 2004-279476 A Japanese Patent No. 3310253 JP 2003-5555 A

  In view of the above problems, an object of the present invention is to provide an image forming apparatus having a short rise time, capable of fixing a toner having a small particle diameter at a low temperature, having no abnormal image, and excellent in durability. is there.

The said subject is achieved by (1)-( 20 ) of this invention.
(1) “An image forming apparatus having a fixing unit for fixing a toner image on a recording medium by heat and pressure, wherein the toner for forming the toner image contains crystalline polyester (A); The fixing unit includes a fixing rotator and a pressure rotator, and a surface layer in contact with the toner image of the fixing rotator is a member made of a fluororesin, and the surface layer includes a number of oxygen atoms / The main component is a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (PFA) having a carbon atom ratio of 1/60 or more, and a surface resistivity of 1 × 10 ⁸ to 1 × 10 ¹¹ Ω / An image forming apparatus characterized by
(2) “Image forming apparatus according to item (1), wherein the fixing nip time of the fixing unit is 30 to 100 msec”
(3) “Image forming apparatus according to item (1) or (2), wherein the fixing pressure of the fixing unit is 0.5 to 4 kgf / cm ² ”.
(4) “The weight average particle diameter of the toner is 3 to 8 μm, and the ratio (D4 / D1) of the weight average particle diameter (D4) to the number average particle diameter (D1) is in the range of 1.00 to 1.40. The image forming apparatus according to any one of (1) to (3) above,
(5) The above-mentioned items (1) to (1), wherein the apparatus is used in an image forming method for forming a multicolor image by superimposing different color toner images, and the toner is a full color toner. The image forming apparatus according to any one of Items (4) "
( 6 ) “The surface layer in contact with the toner image of the fixing rotator is composed of a plurality of types of PFA having different particle diameters and at least one conductive filler selected from carbon black, metal, and metal oxide. The image forming apparatus according to any one of (1) to ( 5 ), characterized in that:
( 7 ) "Image forming apparatus according to any one of (1) to ( 6 ), wherein the glass transition point of the polyester resin (A) is in the range of 80 to 130 ° C"
( 8 ) “The content of the polyester resin (A) in the binder resin of the toner is 3 to 75% by weight, and the volume resistivity value LogR of the toner is 10.5 to 11.2 LogΩ · cm. The image forming apparatus according to any one of items (1) to ( 7 ).
( 9 ) "The toner according to (1), wherein the toner is an electrostatic charge developing toner containing a releasing agent, and the releasing agent has a glass transition point of 70 to 90 ° C." The image forming apparatus according to any one of Items 8 to 8
( 10 ) The item ( 9 ), wherein the release agent is one or more selected from a liberated fatty acid type carnauba wax, a polyethylene wax, a montan wax and an oxidized rice wax. Image forming apparatus described in "
( 11 ) “An image forming fixing device for fixing a toner image on a recording medium by heat and pressure, wherein the toner forming the toner image contains crystalline polyester (A), and the fixing The apparatus has a fixing rotator and a pressure rotator, and the surface layer in contact with the toner image of the fixing rotator is a member made of a fluororesin, and the surface layer includes oxygen atoms / carbon atoms in the molecular chain. The main component is a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (PFA) having a number ratio of 1/60 or more, and the surface resistivity is 1 × 10 ⁸ to 1 × 10 ¹¹ Ω / □. A fixing device characterized by being "
( 12 ) "Fixing device according to item ( 11 ), wherein the fixing nip time of the fixing device is 30 to 100 msec"
( 13 ) “Image forming apparatus according to item ( 11 ) or ( 12 ), wherein the fixing pressure of the fixing device is 0.5 to 4 kgf / cm ² ”.
( 14 ) “The weight average particle diameter of the toner is 3 to 8 μm, and the ratio (D4 / D1) of the weight average particle diameter (D4) to the number average particle diameter (D1) is in the range of 1.00 to 1.40. The fixing device according to any one of ( 11 ) to ( 13 ), wherein
( 15 ) The above ( 11 ) to ( 11 ), wherein the fixing device is used for image formation in which a multicolor image is formed by superimposing toner images of different colors, and the toner is a full color toner. The fixing device according to any one of Items ( 14 )
( 16 ) “The surface layer in contact with the toner image of the fixing rotator is composed of a plurality of types of PFA having different particle diameters and at least one conductive filler selected from carbon black, metal, and metal oxide. The image forming apparatus according to any one of ( 11 ) to ( 15 ), characterized in that:
( 17 ) "The fixing device according to any one of ( 11 ) to ( 16 ), wherein a glass transition point of the polyester resin (A) is in a range of 80 to 130 ° C"
( 18 ) “The content of the polyester resin (A) in the binder resin is 3 to 75% by weight, and the toner has a volume specific resistance LogR of 10.5 to 11.2 LogΩ · cm. The fixing device according to any one of ( 11 ) to ( 17 ) "
(19) "the toner is a toner for electrostatic charge development which contains a releasing agent, wherein the wherein the release agent is one having a glass transition point of 70 to 90 ° C. (11) The fixing device according to any one of Items 18 to 18
( 20 ) The item ( 19 ), wherein the mold release agent is one or more selected from a liberated fatty acid type carnauba wax, a polyethylene wax, a montan wax and an oxidized rice wax. Fixing device "

  According to the present invention, it is possible to provide an image forming apparatus having a short rise time, capable of fixing a toner having a small particle diameter at a low temperature, having no abnormal image, and excellent in durability.

  As a result of examining the fixing method having a short rise time at a low temperature, the inventors of the present invention, as a toner, in a combination of a toner formulated with a crystalline polyester resin excellent in low-temperature fixability and a belt fixing device, the material composition, particle size, It has been found that there are optimum numerical ranges for the surface resistivity, fixing pressure, and fixing nip time of the fixing member of the fixing device.

(Image forming device)
An example of an image forming apparatus according to the present invention is shown in FIG. This image forming apparatus is arranged in order from the upstream side in the moving direction along a conveying belt (20) which is a fixing rotating body for conveying a transfer sheet (P) as a recording medium supplied by a sheet feeding means (30). A so-called tandem type image forming apparatus in which a plurality of image forming units (10Y), (10M), (10C), and (10Bk) are arranged. The moving body driving device according to the present invention can be used as a driving device for the conveyance belt (20) which is a moving body of the tandem type image forming apparatus.
Each image forming unit in this image forming apparatus is configured to sequentially form images of (10Y) yellow, (10M) magenta, (10C) cyan, and (10Bk) black by a known electrophotographic process. Has been. Each of these image forming units has a common internal configuration except that the color of the image to be formed is different. Therefore, as shown in FIG. 1, the image forming units are distinguished from each other by adding the letters Y, M, C, and Bk to the end of the reference numerals indicating the common components. I will do it. In the following description, the configuration of the image forming unit (10Y) is mainly shown, and the configuration of the image forming unit (10Y) is shown to show the configuration of other image forming units.

  In FIG. 1, the conveyance belt (20) located on the upstream side of the fixing device (40) is an endless endless belt. The fixing device (40) has an endless belt (45) in contact with the pressure roller (42), and the conveyor belt (20) is on the opposite side of the driving roller (7) that is driven to rotate. A driven roller (8) that is driven to rotate is stretched in a freely rotating manner, and is rotated in the direction of the arrow by the rotation of the driving roller (7). Below the transport belt (20), a paper feed tray (50) in which a bundle of transfer paper is stored is disposed. Among the transfer paper bundles stored in the paper feed tray (50), the uppermost transfer paper (P) is sent out during image formation and is attracted to the outer peripheral surface of the transport belt (20) by electrostatic attraction. The transfer paper (P) adsorbed on the outer peripheral surface of the transport belt (20) is first transported to the image forming unit (10Y) disposed on the most upstream side in the rotation direction of the transport belt (20).

  The image forming unit (10Y) includes a photosensitive drum (1Y) as an image carrier, a charger (2Y) disposed around the photosensitive drum (1Y), an exposure unit (3Y), and a developing unit (4Y). And a photosensitive member cleaner (6Y). The exposure device (3Y) is composed of a laser scanner, configured to reflect laser light from a laser light source with a polygon mirror, and to emit laser light through an optical system using an fθ lens, a deflection mirror, and the like. Yes. The peripheral surface of the photosensitive drum (1Y) is uniformly charged by the charger (2Y) in the dark during image formation. Thereafter, a laser beam composed of image light corresponding to the yellow image from the exposure unit (3Y) is exposed on the peripheral surface of the charged photosensitive drum (1Y). By this exposure, an electrostatic latent image corresponding to the yellow image is formed on the peripheral surface of the photosensitive drum (1Y). This electrostatic latent image is visualized by yellow toner supplied from the developing device (4Y). As a result, a yellow toner image is formed on the photosensitive drum (1Y).

  The yellow toner image is disposed opposite to the photosensitive drum (1Y) with the conveyance belt (20) interposed therebetween at a transfer position where the photosensitive drum (1Y) and the transfer paper (P) on the conveyance belt (20) are in contact with each other. The image is transferred onto the transfer paper (P) by the transfer device (5Y). By this transfer, a yellow toner image is formed on the transfer paper (P). After the transfer, the photoreceptor drum (1Y) is prepared for the next image formation by removing unnecessary toner remaining on the peripheral surface by the photoreceptor cleaner (6Y).

  In this way, the transfer paper (P) onto which the yellow toner image has been transferred by the image forming unit (1Y) is transported to the next image forming unit (10M) by the transport belt (20). In this image forming unit (10M), a magenta toner image is formed on the photosensitive drum (1M) by the same process as in the case of the image forming unit (10Y). This magenta toner image is superimposed on the yellow toner image on the transfer paper (P) by the transfer device (5M) at the transfer position where the photosensitive drum (1M) and the transfer paper (P) on the conveying belt (20) are in contact. It is transferred together.

  The transfer paper (P) onto which the yellow toner image and the magenta toner image have been transferred is conveyed to the next image forming unit (10C) by the conveyance belt (20). In this image forming unit (10C), a cyan toner image is formed on the photosensitive drum (1C) by the same process as in the case of the image forming units (10Y) and (10M). This cyan toner image is transferred at the transfer position where the photosensitive drum (1C) and the transfer paper (P) on the transport belt (20) are in contact with each other by the transfer device (5C). The toner image is transferred in a superimposed manner.

  The transfer paper (P) on which the yellow, magenta, and cyan toner images are transferred is transported to the next image forming unit (10Bk) by the transport belt (20). In this image forming unit (10Bk), a black toner image is formed on the photosensitive drum (1Bk) in the same manner as in the case of the image forming units (10Y), (10M), and (10C). This black toner image is converted into a toner image of each color on the transfer paper (P) by the transfer device (5Bk) at the transfer position where the photosensitive drum (1Bk) and the transfer paper (P) on the conveying belt (20) are in contact. Overlaid and transferred. As a result, a full-color color image in which the toner images of yellow, magenta, cyan, and black are combined is formed on the transfer paper (2). The transfer paper (P) on which the full-color composite image is formed passes through the image forming unit (10Bk), is peeled off from the transport belt (20), and is fixed by the fixing device (40). The paper is ejected.

(Fixing device details)
FIG. 2 is an explanatory diagram of a belt-type fixing device (40). As shown in FIG. 2, the fixing device (40) includes a fixing belt (45) as an example of a fixing rotating body rotatably provided by a heating roller (44) and a fixing roller (41). . The fixing roller (41) has a heat-resistant sponge rubber layer on the outer periphery of a metal core. The heating roller (44) incorporates heating means such as a halogen lamp (46) in a metal core and heats the fixing belt (45) from the inside by this radiant heat. Further, a thermistor (49), which is a temperature sensor element, is disposed at a position facing the heating roller (44), and contacts the center of the fixing belt (45) to detect the surface temperature of the fixing belt (45). . The heating roller (44) is set to a control set temperature, and based on the temperature detection of the thermistor (49), the lighting of the halogen lamp (46) is controlled by a temperature control device (not shown) so as to reach the set temperature. . Further, a pressure roller (42) as an example of a pressure rotator provided so as to be in contact with the fixing roller (41) via the fixing belt (45) is provided. The pressure roller (42) presses the fixing roller (41) with a spring (43). Further, the pressure roller (42) is rotated by a driving means (not shown), so that the fixing roller (41) is driven to rotate. A tension roller (47) that is in contact with the vicinity of the center of the fixing belt (45) is provided upstream of the fixing nip where the pressure roller (42) is in contact with the moving direction of the fixing belt. The tension roller (47) is pressed to the left side in the drawing by a spring (48), whereby tension is applied to the fixing belt (45). In this embodiment, the driving means is provided on the pressure roller (42). However, the driving means may be provided on the fixing roller (41) and the pressure roller (42) may be rotated. Further, the pressure roller (42) and the fixing roller are engaged with each other by a gear, and the driving force of the driving means is transmitted to both the pressure roller (42) and the fixing roller (41) through the gear. Both (42) and the fixing roller (41) may be driven to rotate.
Such a belt-type fixing device (40) allows the transfer paper to pass between the fixing belt (45) heated by the heating roller (44) and the pressure roller (42), thereby transferring the transfer paper (P). The toner adhering to the toner is pressed by the pressure roller (42) while being softened by the heat of the fixing belt (45) and fixed on the transfer paper. When the fixing belt (40) is omitted, the fixing roller (41) directly contacts the pressure roller (42). Therefore, in such a case, the fixing roller (41) is fixed. Plays the role of a rotating body.

Here, the fixing pressure is preferably 0.5 to ⁴ kgf / cm ² . In order to shorten the rise time image, it is essential to reduce the thickness of the fixing member, and in order to achieve the reduction in thickness, the fixing pressure is preferably low, and is preferably 4 kgf / cm ² or less. On the other hand, in full color image formation in which multicolor images are formed by superimposing different color toner images, multiple overlapping toner layers of different colors are uniformly melted and integrated to form a smooth toner layer. When the fixing pressure is lower than 0.5 kgf / cm ² , the overlapping toner layers of different colors do not melt uniformly and do not form a smooth toner layer, resulting in low image gloss and transparency. Bad image. Further, there are problems such as poor toner fixability due to a small amount of toner deformation during fixing and low image density due to a small toner spread.
The fixing nip time is preferably 30 to 100 msec. In order to increase the printing speed and reduce the size of the apparatus, it is essential to shorten the fixing nip time, and it is preferably 100 msec or less. When the fixing nip time is shorter than 30 msec, the toner heating time is insufficient, so that the same problem as when the fixing pressure is lower than 0.5 kgf / cm ² occurs.

FIG. 3 is a cross-sectional view of the fixing belt (45). As shown in FIG. 3, an elastic layer (452) made of silicone rubber is provided on the outer periphery of a cylindrical film base (451) made of a heat resistant resin such as polyimide via a primer. Further, a release layer (453) made of a fluororesin and having a layer thickness of 20 μm or more is provided on the outer periphery of the elastic layer (452) through a primer.
The substrate (451) may be a material having heat resistance and mechanical strength, and may be, for example, a metal such as Ni or SUS in addition to a heat resistant resin such as polyimide.
The elastic layer (452) may be a material that uniformly applies heat and pressure to the toner and the transfer paper in order to obtain stable fixing performance, and may be a material that has elasticity and heat insulation properties.
The release layer (453) is a known fluororesin such as polytetrafluoroethylene (PTFE), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), or tetrafluoroethylene / hexafluoropropylene copolymer (FEP). Or the material which blended these can be used. The release layer made of the material as described above can be obtained by coating and baking on the elastic layer (452) via a primer.
The release layer (453) uses PFA, which is a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether, which is excellent in bending resistance, non-adhesiveness, and abrasion resistance, so that the fixing belt has good durability. It can be.

Further, in order to remove static electricity on the belt surface and prevent dust and electrostatic offset of the toner image on the transfer material, the surface resistivity needs to be 1 × 10 ¹¹ Ω / □ or less, It is preferable to set it as 1 * 10 < ⁸ > -1 * 10 < ¹¹ > ohm / square. As already described, since the toner of the present invention contains a crystalline polyester, it tends to have a lower volume resistivity LogR than a toner that does not contain a crystalline polyester. When the LogR of the toner is low, the conductivity of the toner becomes high, which leads to defective charging, and tends to increase background contamination, toner scattering, and the like. Also, there is a problem that abnormal images are generated due to electrostatic offset or the like, and a high-quality image cannot be stably obtained. For this, the static electricity on the belt surface is removed and the toner image on the transfer material is removed. In order to prevent dust and electrostatic offset, it is necessary that the surface resistivity be 1 × 10 ¹¹ Ω / □ or less. However, when the conductive filler is dispersed in general PFA and the resistance is lowered, the bending resistance is lowered. Therefore, the number of oxygen atoms / carbon atoms in the molecular chain is increased by increasing the perfluoroalkyl vinyl ether component of PFA. By using PFA having a ratio of 1/60 or more, it is possible to prevent the toner image from dust and electrostatic offset and to provide a release layer with good bending resistance. Accordingly, the surface resistivity is preferably set to 1 × 10 ⁸ to 1 × 10 ¹¹ Ω / □ in the image forming apparatus of the present invention.
One reference for achieving such a range of surface resistivity will be described. For example, when conductive carbon black is added to the surface layer, the surface resistivity is greatly changed, and the addition amount of carbon black is increased. The lower the surface resistivity is. In general, the surface resistance of a PFA layer without addition of carbon black is about 1 × 10 ¹⁴ Ω / □, and the surface resistivity is reduced to 1 × 10 ¹¹ by dispersing conductive filler in general PFA to reduce the resistance. Ω / □ or less. Taking the surface resistivity of a surface layer in which carbon black as a conductive filler is dispersed in a PFA layer as an example, the surface resistivity increases as the amount of carbon black added increases when a good dispersion state is maintained. In order to make the surface resistivity 1 × 10 ⁸ to 1 × 10 ¹¹ Ω / □, the carbon black is preferably 1 to 5%.

FIG. 4 shows the relationship between the addition amount of carbon black, which is the most common conductive filler, and the bending resistance. PFA having a ratio of the number of oxygen atoms / number of carbon atoms in the molecular chain of 1/60 or more is compared with that in the molecular chain. It is the graph which investigated the bending resistance of PFA whose ratio of the number of oxygen atoms / number of carbon atoms is 1/100 or less.
The solid line in the figure is a PFA having a ratio of the number of oxygen atoms / carbon atoms in the molecular chain of 1/60 or more, and the dotted line in the figure has a ratio of oxygen atoms / carbon atoms in the molecular chain of 1 / 100 or less PFA. As can be seen from FIG. 4, regardless of the amount of carbon added, PFA having a ratio of oxygen atoms / carbon atoms in the molecular chain of 1/60 or more has a ratio of oxygen atoms / carbon atoms in the molecular chain. It can be seen that the bending resistance is improved as compared with PFA of 1/100 or less. This is probably because PFA having a ratio of the number of oxygen atoms / number of carbon atoms in the molecular chain of 1/60 or more is suppressed from crystallization and has improved bending resistance (bending life).

Further, when the release layer is formed by applying and baking the fluororesin particles, it is preferable to use at least two types of fluororesins in which a fluororesin having a large particle size and a fluororesin having a small particle size are mixed. Since the fluororesin particles having a small particle size have low cohesiveness, they can be uniformly dispersed in a solvent such as water. However, when a solution consisting only of a solvent and a fluororesin particle having a small particle size is applied to the elastic layer, cracks are likely to occur in the drying process for removing the solvent.
On the other hand, since the fluororesin particles having a large particle size have a strong cohesive force, cracks are unlikely to occur in the drying step after coating. However, since fluororesin particles having a large particle size cannot be sufficiently dispersed in a solvent such as water, when a solution of only a solvent such as water and a fluororesin particle having a large particle size is applied, the fluororesin particles are elastic. It may not adhere uniformly to the layer and may cause so-called coating unevenness. For this reason, as described above, by applying and baking a mixed solution of fluororesin particles having a large particle size and small fluororesin particles, the fluororesin particles can be dispersed in the solvent, thereby eliminating coating unevenness. Can do. Further, in the drying step after application, the generation of cracks can be suppressed by the fluororesin particles having a high particle size and high cohesive force. Thereby, it can be set as the release layer excellent in durability in which generation | occurrence | production of the crack was suppressed.

  In the above description, the release layer is obtained by applying and baking on the elastic layer (452) via a primer. However, the present invention is not limited to this. For example, a fluororesin tube is formed by extruding a fluororesin, A release layer can also be prepared by coating the tube with an elastic layer via a primer and firing. However, when considering the durability and smoothness of the fixing belt (45), the thickness of the release layer is preferably 20 μm or more. When forming a release layer having a thickness of 20 μm or more, the above primer is used. The most suitable method is coating and baking. The fixing belt (45) has a three-layer structure including a film base (451), an elastic layer (452), and a release layer (453). The fixing belt (45) includes a film base (451) and a release layer (453). A two-layer structure may be used.

(Toner particle size)
In order to reproduce minute dots of 600 dpi or more, the toner preferably has a weight average particle diameter of 3 to 8 μm. In this range, since the toner particles have a sufficiently small particle size with respect to the minute latent image dots, the dot reproducibility is excellent.
When the weight average particle diameter (D4) is less than 3 μm, phenomena such as a decrease in transfer efficiency and a decrease in blade cleaning properties tend to occur.
When the weight average particle diameter (D4) exceeds 8 μm, it is difficult to suppress scattering of characters and lines.

Moreover, it is preferable that ratio (D4 / D1) of a weight average particle diameter (D4) and a number average particle diameter (D1) exists in the range of 1.00-1.40.
The closer (D4 / D1) is to 1.00, the sharper the particle size distribution. With such a toner having a small particle size and a narrow particle size distribution, the toner charge amount distribution is uniform, a high-quality image with little background fogging can be obtained, and the electrostatic transfer method has a high transfer rate. can do.

  In the full-color image forming method for forming a multicolor image by superimposing different color toner images, an image is formed with only one color of black toner, so that it is not necessary to superimpose different color toner images. The amount of toner deposited on the paper is large. In other words, since the amount of toner to be developed, transferred and fixed increases, the above-mentioned problems such as lower transfer efficiency, lower blade cleaning performance, scattering of characters and lines, background fogging, etc. are likely to occur. Management of the ratio (D4 / D1) of the diameter (D4) and the weight average particle diameter (D4) to the number average particle diameter (D1) is important.

Next, a method for measuring the particle size distribution of toner particles will be described.
As an apparatus for measuring the particle size distribution of toner particles by the Coulter counter method, there are Coulter Counter TA-II and Coulter Multisizer II (both manufactured by Coulter). The measurement method is described below.
First, 0.1 to 5 ml of a surfactant (preferably alkylbenzene sulfonate) is added as a dispersant to 100 to 150 ml of an aqueous electrolytic solution. Here, the electrolytic solution is a solution prepared by preparing a 1% NaCl aqueous solution using first grade sodium chloride. For example, ISOTON-II (manufactured by Coulter) can be used. Here, 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the measurement device is used to measure the weight and number of toner particles or toner using a 100 μm aperture as an aperture. Calculate weight distribution and number distribution. From the obtained distribution, the weight average particle diameter (D4) and the number average particle diameter (D1) of the toner can be obtained.
As channels, 2.00 to less than 2.52 μm; 2.52 to less than 3.17 μm; 3.17 to less than 4.00 μm; 4.00 to less than 5.04 μm; 5.04 to less than 6.35 μm; 6 Less than 35 to 8.00 μm; less than 8.00 to less than 10.08 μm; less than 10.08 to less than 12.70 μm; less than 12.70 to less than 16.00 μm; less than 16.00 to less than 20.20 μm; Uses 13 channels of less than 40 μm; 25.40 to less than 32.00 μm; 32.00 to less than 40.30 μm, and targets particles having a particle size of 2.00 μm to less than 40.30 μm.

(Toner prescription)
The polyester resin (A) having crystallinity undergoes a crystal transition at the glass transition temperature (Tg), and at the same time, the melt viscosity suddenly decreases from the solid state and exhibits a fixing function to a recording medium such as paper. On the other hand, an amorphous resin usually used as a toner resin has a temperature at which the melt viscosity gradually decreases from Tg, and the melt viscosity decreases as Tg and the fixing function are expressed (for example, softening temperature T (F1 / 2)). There is a difference of several tens of degrees Celsius. Accordingly, in order to fix a toner using only an amorphous resin at a low temperature, it is necessary to lower T (F1 / 2) by lowering the resin Tg or lowering the molecular weight. Heat resistant storage stability and hot offset resistance tend to be insufficient.
Therefore, by combining the polyester resin (A) having crystallinity with an amorphous resin, a decrease in melt viscosity without deteriorating heat storage stability and hot offset resistance, which was not possible with only an amorphous resin. Can achieve low-temperature fixing.

(Toner structure)
The fixing conditions of the present invention, that is, the fixing pressure is 0.5 to 4 kgf / cm ² , the nip time fixing is a low fixing pressure of 30 to 100 msec, and the long fixing nip time penetrates the paper fiber as a recording medium and the toner is melted. The content of the crystalline polyester resin (A) for obtaining a toner having a sufficiently wide spread and high image density on the paper and at the same time having excellent heat-resistant storage stability is intended to exhibit an effect on low-temperature fixability. The amount should be 3 to 75 parts by weight, preferably 5 to 50 parts by weight, based on the total amount of the binder resin for toner. If this amount is large, the effect on fixing at low temperature is great, but if it is too large, the resin having crystallinity deteriorates the hot offset resistance. Therefore, it is preferably at most 75% by weight. Preferably it is 50 weight% or less, More preferably, it is 40 weight% or less.

  Since the resin having crystallinity rapidly decreases in melt viscosity at the glass transition temperature (Tg), the lower limit fixing temperature can be controlled not only by the content but also by Tg and T (F1 / 2). is there. In this invention, it is preferable that it is low in the range which does not deteriorate heat-resistant storage stability, Tg of the polyester resin (A) which has crystallinity is the range of 80-130 degreeC, T (F1 / 2) is the range of 80-130 degreeC. It is preferable that it exists in. When Tg and T (F1 / 2) are lower than the above ranges, it is difficult to synthesize a crystalline polyester that has sharp melt properties and easily exhibits an effect on low-temperature fixability. Since the lower limit temperature becomes high, low temperature fixability cannot be obtained.

  The toner of the present invention contains a crystalline polyester resin (A) and an amorphous resin which are substantially incompatible with each other in the toner, and both are present in an incompatible phase-separated state in the toner. Therefore, it has excellent hot offset resistance and low temperature fixability. That is, in the toner of the present invention, the crystalline polyester resin (A) and the amorphous resin (B ′) exist in a phase-separated state, and therefore the crystalline polyester resin (A) and the amorphous resin ( B ′) develops its own unique properties. That is, the amorphous resin (B ′) having a high T (F1 / 2) increases the elasticity of the toner and improves the hot offset resistance, while the crystalline polyester (A) having a low T (F1 / 2). ) Improves low-temperature fixability.

In the toner, whether or not the polyester resin (A) and the amorphous resin (B ′) exist in a separated state can be confirmed by any of the following methods.
(1) Whether or not a phase separation structure is formed can be confirmed by measuring an endothermic peak due to the first temperature increase in the DSC of the toner. In the DSC endothermic peak measurement, there are at least three endothermic peaks (a), (b) and (c) attributed to the amorphous resin (B ′), the release agent and the crystalline polyester resin (A), respectively. The endothermic peak (a) attributed to the resin (B ′) has a peak top in the range of 40 to 70 ° C., and the endothermic peak (b) attributed to the release agent is in the range of 70 to 90 ° C. The endothermic peak (c) attributed to the polyester resin (A) has a peak top in the range of 80 to 130 ° C.
(2) The presence or absence of the formation of a phase separation structure can be confirmed by X-ray diffraction pattern measurement using a toner powder X-ray diffractometer. This is because, in the case of the toner of the present invention, the polyester resin (A) having crystallinity is present in the toner in a state of being phase-separated from the amorphous resin (B ′) while maintaining crystallinity. A diffraction peak attributed to the polyester resin (A) exists at a position of at least 2θ = 20 ° to 25 °. When the phase separation structure is not formed, the crystalline structure of the crystalline polyester resin (A) belongs to the crystalline polyester resin (A) in order to be compatible with the amorphous resin (B ′) without maintaining the crystalline structure of the crystalline polyester resin (A). A diffraction peak does not appear.

The measurement of the glass transition temperature (Tg) shown in the present specification is specifically determined by the following procedure. Shimadzu TA-60WS and DSC-60 were used as measurement devices, and the measurement was performed under the following measurement conditions.
"Measurement condition"
Sample container: Aluminum sample pan (with lid)
Sample amount: 5mg
Reference: Aluminum sample pan (alumina 10mg)
Atmosphere: Nitrogen (flow rate 50ml / min)
Temperature conditions Starting temperature: 20 ° C
Temperature increase rate: 10 ° C / min
End temperature: 150 ° C
Holding time: None Temperature drop: 10 ° C / min
End temperature: 20 ° C
Holding time: None Temperature increase rate: 10 ° C / min
End temperature: 150 ° C
The measurement results were analyzed using the data analysis software (TA-60, version 1.52) manufactured by Shimadzu Corporation. The analysis method specifies a range of ± 5 ° C centering on the point showing the maximum peak on the lowest temperature side of the DrDSC curve which is the DSC differential curve of the second temperature rise, and the peak temperature is determined using the peak analysis function of the analysis software. Ask. Next, the maximum endothermic temperature of the DSC curve is obtained by using the peak analysis function of the analysis software in the range of the peak temperature + 5 ° C. and −5 ° C. in the DSC curve. The temperature shown here corresponds to the Tg of the toner.

The softening temperature [T (F1 / 2)] shown in the present specification is the melting temperature in the 1/2 method, and the measurement method is as follows. Using an elevated flow tester CFT500 type manufactured by Shimadzu Corporation, the flow curve of this flow tester is the data shown in FIG. 5, from which each temperature can be read. In FIG. 5, the melting temperature in the 1/2 method corresponds to [T (F1 / 2)] of the present invention.
"Measurement condition"
Load: 30 kg / cm ² ,
Temperature increase rate: 3.0 ° C./min,
Die diameter: 0.50 mm,
Die length: 1.0mm

Since the toner of the present invention contains the crystalline polyester (A), the volume specific resistance value LogR tends to be lower than that of the toner not containing the crystalline polyester. This is a phenomenon derived from the fact that the crystalline polyester (A) has crystallinity and therefore has a lower volume resistivity than the amorphous resin (B ′). The LogR of the toner of the present invention is preferably 10.5 to 11.2 LogΩ · cm, and particularly preferably 10.7 to 11.15 LogΩ · cm. Since LogR becomes harder as the content of the crystalline polyester (A) is lower or when a high kneading share is applied to the melt blending range, the LogR is adjusted by the content of the crystalline polyester (A) and the kneading share at the time of melt kneading.
When the LogR of the toner is smaller than 10.5 LogΩ · cm, the conductivity becomes high, thereby causing a charging failure, and there is a tendency to increase background contamination and toner scattering. In addition, an abnormal image is generated due to electrostatic offset or the like, and a high-quality image cannot be obtained stably. In addition, when the LogR of the toner is 11.2 LogΩ · cm or more, the resistance increases, so that the charge amount increases and the image density tends to decrease.

The volume specific resistance LogR of the toner was measured as follows.
As a sample, 3 g of toner was pressed for 1 minute under a load of 6 t with an automatic pellet molding machine (Type M No. 50 BRP-E; manufactured by MAEKAWA TESTING MACHINE CO.) To produce 40 mmφ (thickness: about 2 mm) pellets.
This is set on SE-70 type solid electrode (manufactured by Ando Electric Co., Ltd.), and LogR when AC of 1 kHz is applied between the electrodes is TR-10C type dielectric loss measuring instrument, WBG-9. Measurement was performed with a measuring instrument including an oscillator and a BDA-9 equilibrium point detector (both manufactured by Ando Electric Co., Ltd.), and thereby the volume specific resistance value LogR of the toner was determined. RATIO is 1 × 10 ^-9 . The measurement environment is room temperature 25 ° C. and humidity 50%.

(Crystalline polyester (A))
The polyester resin (A) having crystallinity used in the present invention is characterized by comprising a crystalline aliphatic polyester resin containing an ester bond represented by the following general formula (1) in its molecular main chain.
_{-OCOC-R-COO- (CH 2} ) n- (1)
In the above formula, R represents a linear unsaturated aliphatic divalent carboxylic acid residue, and is a linear unsaturated aliphatic group having 2 to 20 carbon atoms, preferably 2 to 4 carbon atoms. n is an integer of 2 to 20, preferably 2 to 6.

The presence of the structure of the general formula (1) can be confirmed by solid C13 NMR.
Specific examples of the linear unsaturated aliphatic group include linear unsaturated divalent carboxylic acids such as maleic acid, fumaric acid, 1,3-n-propene dicarboxylic acid, and 1,4-n-butene dicarboxylic acid. Mention may be made of linear unsaturated aliphatic groups derived from acids.
In the general formula (1), (CH ₂ ) n represents a linear aliphatic dihydric alcohol residue. Specific examples of the linear aliphatic dihydric alcohol residue in this case include linear aliphatic 2 such as ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, and 1,6-hexanediol. Those derived from dihydric alcohols can be indicated. Since the polyester resin (A) uses a linear unsaturated aliphatic dicarboxylic acid as an acid component, the polyester resin (A) exhibits an effect that a crystal structure is easily formed as compared with the case of using an aromatic dicarboxylic acid.

The polyester resin (A) is a polyvalent carboxylic acid comprising (i) a linear unsaturated aliphatic divalent carboxylic acid or a reactive derivative thereof (an acid anhydride, a lower alkyl ester having 1 to 4 carbon atoms, an acid halide, etc.). It can be produced by subjecting an acid component and (ii) a polyhydric alcohol component composed of a linear aliphatic diol to a polycondensation reaction by a conventional method. In this case, a small amount of other polyvalent carboxylic acid can be added to the polyvalent carboxylic acid component as necessary. In this case, the polyvalent carboxylic acid includes (i) an unsaturated aliphatic divalent carboxylic acid having a branched chain, (ii) a saturated aliphatic divalent carboxylic acid, and a saturated aliphatic trivalent carboxylic acid. In addition to polyvalent carboxylic acids, (iii) aromatic polyvalent carboxylic acids such as aromatic divalent carboxylic acids and aromatic trivalent carboxylic acids are included. The addition amount of these polyvalent carboxylic acids is usually 30 mol% or less, preferably 10 mol% or less, based on the total carboxylic acid, and is appropriately added within the range where the resulting polyester has crystallinity.
In other words, the crystallinity depends on the combination of the alcohol component and the acid component used, but a crystalline one can be formed by the combination of the aliphatic alcohol component and the acid component. Hydroxy compounds and acids are bulky, and it is difficult to form a crystalline part because it is difficult to regularly arrange molecules. The values of 10 mol% or less and 30 mol% or more will be further described. In the method for confirming the crystallinity of the synthesized resin, generally, confirmation is easy at 10 mol% or less, and at 30 mol% or more, It becomes difficult to recognize the crystallinity of the resin.

Specific examples of polyvalent carboxylic acids that can be added as needed include malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, citraconic acid, phthalic acid, isophthalic acid, terephthalic acid, etc. A divalent carboxylic acid of: trimethic anhydride, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, And trivalent or higher polyvalent carboxylic acids such as 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methylenecarboxypropane, 1,2,7,8-octanetetracarboxylic acid, etc. it can.
A trivalent or higher polyhydric alcohol can be added to the polyhydric alcohol component, if necessary, in addition to a small amount of an aliphatic branched dihydric alcohol or cyclic dihydric alcohol. The addition amount is 30 mol% or less, preferably 10 mol% or less, based on the total alcohol, and is appropriately added within the range in which the resulting polyester has crystallinity.
Examples of polyhydric alcohol added as needed include 1,4-bis (hydroxymethyl) cyclohexane, polyethylene glycol, bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct, glycerin and the like.

In the crystalline polyester resin (A), the molecular weight distribution is preferably sharp from the viewpoint of low-temperature fixability, and the molecular weight is preferably a relatively low molecular weight. As for the molecular weight of the polyester resin (A), the weight average molecular weight (Mw) is 5500-6500, the number average molecular weight (Mn) is 1300-1500 and The Mw / Mn ratio is preferably 2-5.
The molecular weight distribution of the polyester resin (A) is based on a molecular weight distribution chart in which the horizontal axis is log (M: molecular weight) and the vertical axis is weight%. In the case of the polyester resin (A) used in the present invention, in this molecular weight distribution diagram, it is preferable to have a molecular weight peak in the range of 3.5 to 4.0 (wt%), and the half width of the peak is 1. 5 or less is preferable.

In the crystalline polyester resin (A), the glass transition temperature (Tg) and the softening temperature [T (F1 / 2)] are desirably low as long as the heat-resistant storage stability of the toner is not deteriorated. Its Tg is 80-130 ° C, preferably 80-125 ° C, and its T (F1 / 2) is 80-130 ° C, preferably 80-125 ° C. When Tg and T (F1 / 2) are higher than the above ranges, the lower limit fixing temperature of the toner is increased, so that the low temperature fixing property of the toner is deteriorated.

Whether or not the resin fine particles in the present invention have crystallinity can be confirmed by whether or not a peak exists in the X-ray diffraction pattern by the powder X-ray diffractometer. In the diffraction pattern of the polyester resin A having crystallinity used in the present invention, at least one diffraction peak is present at a position where 2θ is 20 ° to 25 °, and preferably 2θ is at least (i) 19 A diffraction peak is present at positions of 20 ° to 20 °, (ii) 21 ° to 22 °, (iii) 23 ° to 25 °, and (iv) 29 ° to 31 °.
Whether or not the resin fine particles in the present invention have crystallinity can be confirmed by whether or not a peak exists in the X-ray diffraction pattern by the powder X-ray diffractometer. In the diffraction pattern of the polyester resin A having crystallinity used in the present invention, at least one diffraction peak is present at a position where 2θ is 20 ° to 25 °, and preferably 2θ is at least (i) 19 Diffraction peaks are present at positions of ° to 20 °, (ii) 21 ° to 22 °, (iii) 23 ° to 25 °, and (iv) 29 ° to 31 °.
Powder X-ray diffraction measurement was carried out by using a Rigaku Electric RINT1100 with a powder sample placed on a slide glass, using a wide-angle goniometer under the conditions of a tube with Cu and a tube voltage-current of 50 kV-30 mA.

(Amorphous resin (B '))
The binder resin used in combination with the polyester resin (A) having crystallinity is an amorphous (non-crystalline) resin (B ′), and conventionally known resins can be used for this. For example, styrene, α-methylstyrene, chlorostyrene, styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, Styrene resins such as styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-acrylonitrile-acrylic acid ester copolymer, polyester resin, vinyl chloride resin, rosin modified maleic acid resin, phenol resin, There are epoxy resins, polyethylene resins, polypropylene resins, ionomer resins, polyurethane resins, silicone resins, ketone resins, xylene resins, petroleum resins, hydrogenated petroleum resins, and the like. Of these resins (B ′), styrene resins and polyester resins containing an aromatic compound as a component are preferable. Particularly preferred is a polyester resin (B).

The amorphous polyester resin (B) is synthesized from a polyhydric alcohol and a polyvalent carboxylic acid. As the polyhydric alcohol and polycarboxylic acid, the components used in the crystalline polyester resin (A) can be used. Besides this, alkylene oxide adducts of bisphenol A, isophthalic acid, terephthalic acid and derivatives thereof are also available. is there.
These resins are not limited to single use but can be used in combination of two or more.

The molecular structure of the polyester resins (A) and (B) is not limited, but in particular, the alcohol component is at least one of bisphenol A propylene oxide adduct and bisphenol A ethylene oxide adduct, and the acid component is a non-carbon component. It is desirable to have a saturated double bond, and it is particularly desirable to contain at least fumaric acid, maleic acid and derivatives thereof.
When the acid component of the polyester resin (A) and the polyester resin (B) has an unsaturated double bond between carbons, the unsaturated double bond between the carbons of the polyester (A) in the melt-kneading step in toner production The unsaturated double bond between carbon of the polyester resin (B) interacts, and the polyester (A) and the polyester resin (B) are finely dispersed and mixed. This is due to partial plasticization at the interface between the domains of both resins. On the other hand, when either of the polyester resin (A) and the polyester resin (B) has no unsaturated double bond between carbons, the differential oxidation is not performed and the offset of the polyester resin (A) domain (hot There is a problem that the offset of the polyester resin (B) domain and the offset of the polyester resin (B) are easily generated.

  The molecular weight of the polyester resin (B) used in the present invention is such that the weight average molecular weight (Mw) is 3000 to 100,000, the number average molecular weight (Mn) is 1500 to 4000, and The Mw / Mn ratio is preferably 2-50.

The molecular weight distribution of the polyester resin (B) is based on a molecular weight distribution chart in which the horizontal axis is log (M: molecular weight) and the vertical axis is weight%. In the case of the polyester resin (B) used in the present invention, in this molecular weight distribution diagram, it is preferable to have a molecular weight peak in the range of 2.5 to 4.5 (% by weight).
The measuring method of the molecular weight distribution of the polyester resin (polyester resin (B)) having no crystallinity is as follows. GPC-150C (manufactured by Waters) is used as an apparatus, the column is stabilized in a heat chamber at 40 ° C., and THF as a solvent is allowed to flow through the column at this temperature at a flow rate of 1 ml / min. The concentration is measured by injecting 0.1 ml.
The THF sample solution of the resin was prepared by stirring a THF solution having a resin concentration of 0.5% by weight with a ball mill at room temperature for 24 hours, and then filtering with a 0.2 μm hole diameter membrane filter manufactured by Toyo Filter Paper Co., Ltd. is there. Waters GPC-150C can be used as a measuring device, and Shodex KF801-807 can be used as a column. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts. As a standard polystyrene sample for preparing a calibration curve, for example, Pressure Chemical Co. Alternatively, the molecular weights manufactured by Toyo Soda Industry Co., Ltd. are 6 × 102, 2.1 × 103, 4 × 103, 1.75 × 104, 5.1 × 104, 1.1 × 105, 3.9 × 105, 8.6. It is appropriate to use those of × 105, 2 × 106, 4.48 × 106, and at least about 10 standard polystyrene samples. An RI (refractive index) detector is used as the detector.

  In the polyester resin (B), the glass transition temperature (Tg) and the softening temperature [T (F1 / 2)] are desirably low so long as the heat resistant storage stability of the toner is not deteriorated. Is 45 to 75 ° C., preferably 50 to 70 ° C., and T (F1 / 2) is 90 to 150 ° C., preferably 90 to 130 ° C. When Tg and T (F1 / 2) are higher than the above ranges, the lower limit fixing temperature of the toner is increased, so that the low temperature fixing property of the toner is deteriorated.

(Release agent)
As the release agent used for the toner in the present invention, known ones can be used, and in particular, a free fatty acid type carnauba wax, a polyethylene wax, a montan wax and an oxidized rice wax can be used alone or in combination. The carnauba wax is preferably a microcrystalline one, having an acid value of 5 or less and a particle size of 1 μm or less when dispersed in a toner binder. The montan wax generally refers to a montan wax refined from minerals, and like a carnauba wax, it is microcrystalline and preferably has an acid value of 5 to 14. The oxidized rice wax is obtained by air-oxidizing rice bran wax, and the acid value is preferably 10-30. The reason is that these waxes are finely dispersed in the toner binder resin of the present invention, so that it is easy to obtain a toner excellent in offset prevention, transferability and durability as described later. These waxes can be used alone or in combination of two or more.
As other mold release agents, any conventionally known mold release agents such as solid silicone wax, higher fatty acid higher alcohol, montan ester wax, polyethylene wax and polypropylene wax can be mixed and used.

  The Tg of the release agent used in the toner of the present invention is preferably 70 to 90 ° C. If it is less than 70 ° C., the heat-resistant storage stability of the toner is deteriorated, and if it exceeds 90 ° C., the releasability at a low temperature is not expressed, the cold offset resistance is deteriorated, and the paper is wound around the fixing machine. The amount of these release agents used is 1 to 20 parts by weight, preferably 3 to 10 parts by weight, based on the toner resin component. If it is less than 1% by weight, the effect of preventing offset is insufficient, and if it exceeds 20% by weight, transferability and durability are deteriorated.

(Coloring agent)
As the colorant used in the color toner of the present invention, known pigments and dyes capable of obtaining toners of yellow, magenta, cyan and black colors can be used.
Examples of yellow pigments include cadmium yellow, mineral fast yellow, nickel titanium yellow, navel yellow, naphthol yellow S, Hansa Yellow G, Hansa Yellow 10G, Benzidine Yellow GR, Quinoline Yellow Lake, Permanent Yellow NCG and Tartrazine Lake. Can be mentioned.
Examples of the orange pigment include molybdenum orange, permanent orange GTR, pyrazolone orange, Vulcan orange, indanthrene brilliant orange RK, benzidine orange G, and indanthrene brilliant orange GK.
Examples of red pigments include Bengala, Cadmium Red, Permanent Red 4R, Resol Red, Pyrazolone Red, Watching Red Calcium Salt, Lake Red D, Brilliant Carmine 6B, Eosin Lake, Rhodamine Lake B, Alizarin Lake, Brilliant Carmine 3B.
Examples of purple pigments include fast violet B and methyl violet lake.
Examples of blue pigments include cobalt blue, alkali blue, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partially chlorinated, first sky blue, and indanthrene blue BC.
Examples of the green pigment include chrome green, chromium oxide, pigment green B, and malachite green lake.
Examples of black pigments include azine dyes such as carbon black, oil furnace black, channel black, lamp black, acetylene black, and aniline black, metal salt azo dyes, metal oxides, and composite metal oxides.
These can use 1 type (s) or 2 or more types.

(CCA)
The color toner of the present invention can contain a charge control agent in the toner as needed.
For example, nigrosine, an azine dye containing an alkyl group having 2 to 16 carbon atoms (described in JP-B No. 42-1627), a basic dye such as C.I. I. Basic Yellow 2 (C.I. 41000), C.I. I. Basic Yellow 3, C.I. I. Basic Red 1 (C.I. 45160), C.I. I. Basic Red 9 (C.I. 42500), C.I. I. Basic Violet 1 (C.I. 42535), C.I. I. Basic Violet 3 (C.I. 42555), C.I. I. Basic Violet 10 (C.I. 45170), C.I. I. Basic Violet 14 (C.I. 42510), C.I. I. Basic Blue 1 (C.I. 42025), C.I. I. Basic Blue 3 (C.I. 51005), C.I. I. Basic Blue 5 (C.I. 42140), C.I. I. Basic Blue 7 (C.I. 42595), C.I. I. Basic Blue 9 (C.I. 52015), C.I. I. Basic Blue 24 (C.I. 52030), C.I. I. Basic Blue 25 (C.I. 52025), C.I. I. Basic Blue 26 (C.I. 44045), C.I. I. Basic Green 1 (C.I. 42040), C.I. I. Basic Green 4 (C.I. 42000) and the like and lake pigments of these basic dyes, C.I. I. Solvent Black 8 (C.I. 26150), quaternary ammonium salts such as benzoylmethyl hexadecyl ammonium chloride, decyl trimethyl chloride, or dialkyl tin compounds such as dibutyl or dioctyl, dialkyl tin borate compounds, guanidine derivatives, containing amino groups Polyamine resins such as vinyl polymers, condensation polymers containing amino groups, etc. Metal complex salts of monoazo dyes described, Japanese Patent Publication No. 55-42752, Japanese Patent Publication No. 59-7385, salicylic acid, dialkylsalicylic acid, naphthoic acid, dicarboxylic acid Zn, Al, Co, Cr , Fe, etc. Metal complex, a copper phthalocyanine pigment obtained by sulfonation, organic boron salts, fluorine-containing quaternary ammonium salts, calixarene compounds, and the like. Naturally, color toners other than black should avoid the use of charge control agents that impair the target color, and white metal salts of salicylic acid derivatives are preferably used.

(Additive)
In the toner of the present invention, transferability and durability can be further improved by externally adding inorganic fine particles such as silica, titanium oxide, alumina, silicon carbide, silicon nitride, boron nitride, and resin fine particles to the base toner particles. it can.
This effect can be obtained by covering the wax that lowers transferability and durability with these external additives and reducing the contact area due to the toner surface being covered with fine particles. The surface of these inorganic fine particles is preferably subjected to a hydrophobic treatment, and metal oxide fine particles such as silica and titanium oxide subjected to the hydrophobic treatment are preferably used. As the resin fine particles, polymethyl methacrylate or polystyrene fine particles having an average particle size of about 0.05 to 1 μm obtained by a soap-free emulsion polymerization method are suitably used. In addition, the combination of hydrophobized silica and hydrophobized titanium oxide increases the amount of hydrophobized titanium oxide externally added compared to the amount of hydrophobized silica externally charged. The toner can also be excellent in stability. In combination with the above-mentioned inorganic fine particles, silica having a specific surface area of 20 to 50 m ² / g and resin fine particles having an average particle diameter of 1/100 to 1/8 of the average particle diameter of the toner are conventionally used. The durability can be improved by externally adding an external additive having a particle size larger than that of the additive to the toner. This is because the metal oxide particles externally added to the toner tend to be embedded in the base toner particles in the process where the toner is mixed and stirred with the carrier in the developing device, charged, and used for development. This is because it is possible to prevent the metal oxide fine particles from being embedded by externally adding an external additive having a particle size larger than that of the oxide fine particles to the toner.
In addition, the above-mentioned inorganic fine particles and resin fine particles are contained (internally added) in the toner, but the effect is reduced compared with the case of external addition, but the effect of improving transferability and durability is obtained and the toner pulverization property is improved. Can be made. In addition, since external addition and internal addition can be used together to suppress embedding of externally added fine particles, excellent transferability can be stably obtained and durability can be improved.

In addition, the following are mentioned as a typical example of the hydrophobization processing agent used here.
Dimethyldichlorosilane, trimethylchlorosilane, methyltrichlorosilane, allyldimethyldichlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, p-chloroethyltrichlorosilane, Chloromethyldimethylchlorosilane, chloromethyltrichlorosilane, p-chlorophenyltrichlorosilane, 3-chloropropyltrichlorosilane, 3-chloropropyltrimethoxysilane, vinyltriethoxysilane, vinylmethoxysilane, vinyl-tris (β-methoxyethoxy) ) Silane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, divinyldichlorosilane, dimethylvinylchlorosilane, octyl Trichlorosilane, decyl-trichlorosilane, nonyl-trichlorosilane, (4-t-propylphenyl) -trichlorosilane, (4-t-butylphenyl) -trichlorosilane, diventyl-dichlorosilane, dihexyl-dichlorosilane, dioctyl-dichlorosilane, dinonyl -Dichlorosilane, didecyl-dichlorosilane, didodecyl-dichlorosilane, dihexadecyl-dichlorosilane, (4-t-butylphenyl) -octyl-dichlorosilane, dioctyl-dichlorosilane, didecenyl-dichlorosilane, dinonenyl-dichlorosilane, di-2-ethylhexyl-dichlorosilane, di- 3,3-dimethylbenthyl-dichlorosilane, trihexyl-chlorosilane, trioctyl-chlorosilane, tridecyl-chlorosilane Dioctyl-methyl-chlorosilane, octyl-dimethyl-chlorosilane, (4-t-propylphenyl) -diethyl-chlorosilane, octyltrimethoxysilane, hexamethyldisilazane, hexaethyldisilazane, diethyltetramethyldisilazane, hexaphenyldisilazane , Hexatolyl disilazane and the like. In addition, titanate coupling agents and aluminum coupling agents can also be used. In addition, as an external additive for the purpose of improving the cleaning property, a lubricant such as an aliphatic metal salt or a fine particle of polyvinylidene fluoride can be used in combination.

(Toner manufacturing method)
As a method for producing the toner of the present invention, a conventionally known method such as a melt kneading-pulverizing method or a polymerization method can be applied. The polymerization method is different from the other polymerization methods such as suspension polymerization method, emulsion polymerization method, dispersion polymerization method and the like, but other than dissolution suspension method, polymer suspension method, etc., extension reaction method and the like can be used.

  Hereinafter, the present invention will be described more specifically with reference to the following examples, but the present invention is not limited thereto. All parts are parts by weight.

<Toner Production Example 1>
Crystalline polyester resin A1 15 parts Amorphous polyester resin B-H1 55 parts Amorphous polyester resin B-L1 30 parts Salicylic acid Zr salt (Hodogaya Chemical TN-105) 1 part Desorbed free fatty acid type carnauba wax (Tg: 83 5 parts Carbon black (Mitsubishi Chemical # 44) 10 parts The above toner constituent materials were sufficiently stirred and mixed in a Henschel mixer, and then melt-kneaded in a twin-screw extruder. Regarding the kneading conditions, as a result of setting the temperature of the kneader to knead the kneaded material at a low temperature (minimum temperature within the range where the kneaded material is in a molten state), the kneading material is mixed at the kneader outlet. The temperature of the kneader was set so that the temperature of the smelted product was 120 ° C. Next, the kneaded product was coarsely pulverized to a particle size of 1 mm or less using an AP pulverizer manufactured by Hosokawa Micron Co., and then finely pulverized using a turbo mill manufactured by Turbo Industries Co., Ltd. to obtain a toner base having a weight average particle size of 6.5 μm. The obtained toner base was classified, and 0.5 wt% of hydrophobic silica (average primary particle size 20 nm, bulk density 0.15 mg / cm ² ) and 0.3 wt% of titanium oxide were added and mixed to obtain a final toner. The toner has a LogR of 10.9 LogΩ · cm, SF1 of 159, SF2 of 160, and D4 / D1 of 1.21.

<Toner Production Example 2>
A toner was prepared in the same manner as in Toner Production Example 1 except that Polyester A1 was changed to Polyester A2 in Toner Production Example 1. The toner has a LogR of 11.15 LogΩ · cm, SF1 of 156, SF2 of 159, and D4 / D1 of 1.22.
<Toner Production Example 3>
A toner was prepared in the same manner as in Toner Production Example 1 except that Polyester A1 was changed to Polyester A3 in Toner Production Example 1. The toner has a LogR of 10.9 LogΩ · cmSF1 of 157, SF2 of 158, and D4 / D1 of 1.20.
<Toner Production Example 4>
A toner was prepared in the same manner as in Toner Production Example 1 except that Polyester A1 was changed to Polyester A4 in Toner Production Example 1. The toner has a LogR of 10.9 LogΩ · cm, SF1 of 160, SF2 of 163, and D4 / D1 of 1.22.
<Toner Production Example 5>
A toner was obtained in the same manner as in Toner Production Example 1 except that the de-free fatty acid type carnauba wax in Toner Production Example 1 was changed to polyethylene wax (Tg 110 ° C.). The toner has a LogR of 10.89 LogΩ · cmSF1 of 159, SF2 of 160, and D4 / D1 of 1.21.
<Toner Production Example 6>
A toner was obtained in the same manner as in Toner Production Example 1 except that the de-free fatty acid type carnauba wax in Toner Production Example 1 was changed to polyethylene wax (Tg 58 ° C.). The toner has a LogR of 10.89 LogΩ · cm SF1 of 158, SF2 of 161, and D4 / D1 of 1.19.
<Toner Production Example 7>
A toner was prepared in the same manner as in Toner Production Example 1 except that the weight average particle size of the finely pulverized toner base was 2.7 μm in Toner Production Example 1. The toner has a LogR of 10.9 LogΩ · cm, SF1 of 149, SF2 of 154, and D4 / D1 of 1.42.
<Toner Production Example 8>
A toner was prepared in the same manner as in Toner Production Example 1 except that the weight average particle size of the finely pulverized toner base was 9.0 μm in Toner Production Example 1. The toner has a LogR of 10.9 LogΩ · cm, SF1 of 163, SF2 of 166, and D4 / D1 of 1.10.

<Toner Production Example 9>
A toner was prepared in the same manner as in Toner Production Example 1 except that the formulation was changed to the following.
Crystalline polyester resin A1 77 parts Amorphous polyester resin B-H1 15 parts Amorphous polyester resin B-L1 8 parts Salicylic acid Zr salt (Hodogaya Chemical TN-105) 1 part Desorbed fatty acid type carnauba wax (Tg: 83 5 parts Carbon black (Mitsubishi Chemical # 44) 10 parts The toner has a LogR of 10.2 LogΩ · cm, SF1 of 154, SF2 of 159, and D4 / D1 of 1.22.

<Toner Production Example 10>
A toner was prepared in the same manner as in Toner Production Example 1 except that the formulation was changed to the following.
Crystalline polyester resin A1 2.5 parts Amorphous polyester resin B-H1 67.5 parts Amorphous polyester resin B-L1 30 parts Salicylic acid Zr salt (Hodogaya Chemical TN-105) 1 part Desorbed fatty acid type carnauba wax (Tg: 83 ° C.) 5 parts Carbon black (Mitsubishi Chemical # 44) 10 parts The toner has a LogR of 11.1 LogΩ · cmSF1 of 158, SF2 of 160, and D4 / D1 of 1.20.

<Manufacture of polyester A>
Polyesters A1 to A4 were charged with 4000 g of the composition shown in Table 1 and 4 g of hydroquinone in a 5 L four-necked round bottom flask equipped with a thermometer, stirrer, condenser and nitrogen gas inlet tube. Set in a heater, introduce nitrogen gas from the nitrogen gas inlet tube, raise the temperature in a state where the flask is kept in an inert atmosphere, and maintain at 160 ° C. for 5 hours, and then react at 200 ° C. for 1 hour. Each polyester was obtained by reaction at 8.3 kPa for 1 hour.
Table 1 shows components of each polyester A1 to A4, and Table 2 shows physical property values of each polyester A1 to A4.
BPA / EO shown in Table 1 represents an ethylene oxide adduct of bisphenol A (2.2 mol adduct), and BPA / PO represents a propylene oxide adduct of bisphenol A (2.2 mol adduct). Indicates.

（注）ポリエステルＡ２のみ酸成分、アルコール成分ともに重量比

(Note) Only polyester A2 has a weight ratio for both acid and alcohol components.

なお、結晶性の有りのものとは、粉末Ｘ線回折装置によるＸ線回折パターンにおいて、少なくとも２θ＝１９〜２０°、２１〜２２°、２３〜２５°、２９〜３１°の位置に回折ピークが現れたものである。推定分子式有りのものとは固体Ｃ１３ＮＭＲにより一般式（１）の分子構造の存在が確認されたものである。

In addition, the thing with crystallinity is a diffraction peak in the position of at least 2 (theta) = 19-20 degrees, 21-22 degrees, 23-25 degrees, 29-31 degrees in the X-ray-diffraction pattern by a powder X-ray-diffraction apparatus. Appears. Those having an estimated molecular formula are those in which the presence of the molecular structure of the general formula (1) has been confirmed by solid-state C13 NMR.

<Manufacture of polyester B>
Polyester B-H1 and B-L1 were prepared by placing 4000 g of the composition shown in Table 3 into a 5-L four-necked round bottom flask equipped with a thermometer, stirrer and condenser, and setting the flask in a mantle heater. Then, 4 g of dibutyltin oxide was added, the temperature was raised, the temperature was kept at 220 ° C., and the reaction was carried out for 8 hours. Then, the reaction was carried out at 8.3 kPa until a predetermined softening point was reached, thereby obtaining each polyester.
Table 3 shows the components of each polyester B-H1 and B-L1, and Table 4 shows the physical property values thereof.
BPA / EO shown in Table 3 represents an ethylene oxide adduct of bisphenol A (2.2 mol adduct), and BPA / PO represents a propylene oxide adduct of bisphenol A (2.2 mol adduct). Indicates.

<Example of carrier production>
(I) Core material: Cu—Zn ferrite particles (volume average diameter: 45 μm) 5000 parts (ii) Coating material Toluene 450 parts Silicone resin SR2400
(Toray Dow Corning Silicone, 50% nonvolatile content) 450 parts Aminosilane SH6020
(Toray / Dow Corning / Silicone) 10 parts Carbon black 10 parts The above coating material is dispersed with a stirrer for 10 minutes to prepare a coating liquid, and this coating liquid and core material are placed in a fluidized bed. The coating liquid was applied to the core material, and the coating liquid was applied to the coating material while coating while forming a swirling flow.
Next, the obtained carrier was baked in an electric furnace at 250 ° C. for 2 hours, and the carrier particles of the production example (saturation magnetization 65 emu / g when 3 kOe was applied, residual magnetization 0 emu / g when 3 kOe was applied, specific resistance 3.2). × 10 ⁸ Ω · cm, volume average diameter 45 μm) was obtained.

<Examples of developer production>
Developer (1) corresponding to each toner corresponding to Toner Production Examples 1 to 10 by mixing 2.5 parts of the toner of Production Examples 1 to 10 and 97.5 parts of the carrier of the above Production Examples with a tumbler mixer To (10) was obtained.

Evaluation Method of Resin Physical Properties Measurement of Molecular Weight by GPC (1) Measurement of Molecular Weight by GPC of Polyester B-H1, B-L1, and Polyester A2 The measurement method of molecular weight distribution is as follows. GPC-150C (manufactured by Waters) is used as an apparatus, the column is stabilized in a heat chamber at 40 ° C., and THF as a solvent is allowed to flow through the column at this temperature at a flow rate of 1 ml / min. The concentration is measured by injecting 0.1 ml.
The THF sample solution of the resin was prepared by stirring a THF solution having a resin concentration of 0.5% by weight with a ball mill at room temperature for 24 hours, and then filtering with a 0.2 μm hole diameter membrane filter manufactured by Toyo Filter Paper Co., Ltd. is there. Waters GPC-150C can be used as a measuring device, and Shodex KF801-807 can be used as a column. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts. As a standard polystyrene sample for preparing a calibration curve, for example, Pressure Chemical Co. Alternatively, the molecular weights manufactured by Toyo Soda Industry Co., Ltd. are 6 × 102, 2.1 × 103, 4 × 103, 1.75 × 104, 5.1 × 104, 1.1 × 105, 3.9 × 105, 8.6. It is appropriate to use those of × 105, 2 × 106, 4.48 × 106, and at least about 10 standard polystyrene samples. An RI (refractive index) detector is used as the detector.

(2) Measurement of molecular weight by GPC of polyesters A1 and A3 to A4 GPC (gel permeation chromatography) is measured as follows.
The column was stabilized in a heat chamber at 145 ° C., and O-dichlorobenzene containing 0.3% BHT as an eluent was allowed to flow through the column at this temperature at a flow rate of 1 ml / min to a sample concentration of 0.3% by weight. Measurement is performed by injecting 50 to 200 μl of 140 ° C. O-dichlorobenzene solution of the prepared resin. Waters 150CV type can be used as a measuring instrument, and Shodex AT-G + AT-806MS (two) can be used as a column.

-Molecular structure of resin Using solid C13-NMR (FT-NMR SYSTEM JNM-α400 manufactured by JEOL Ltd.), observation nucleus C13, reference material adamantane, accumulated number 8192 times, pulse series CPMAS. IRMOD: IRLEV, observation frequency 100.4 MHz, OBSET: 134500 Hz, POINT: 4096, PD: 7.0 sec, SPIN 6088 Hz, and molecular structure estimation is performed by Chem Draw Pro Ver. 4.5.
The following two measurements were used in combination to confirm the results of molecular structure analysis by solid C13-NMR.
(A) A sample is measured by a Fourier transform infrared spectrophotometry (FT-IR) transmission method, and a structure is estimated from standard spectrum comparison.
Measuring machine: Nicolet Magna 850
Measurement range: 4000 to 400 cm-1
Standard sample: KBr
(B) Thermal decomposable organism structure estimation by pyrolysis gas chromatogram mass spectrometer Measuring instrument: Shimadzu Corporation GC-17A, Shimadzu CR-4A
Thermal decomposition temperature: Nippon Analytical Industry JHB-3S
Thermal decomposition temperature: sample heating temperature × time is 590 ° C. × 4 seconds Column: DB-5 (J and W Co.) L = 30 m, I.V. D = 0.2
5mm, Film = 0.25mm
Column temperature: raised from 50 ° C. (holding time 1 minute) to 300 ° C. at 10 ° C./min Injection temperature: 320 ° C.
Carrier gas pressure: From 90 kPa (holding time 2 minutes) to 2 kPa / min, 150
Boost to kPa Detector: FID

The evaluation methods and conditions in the examples are shown below.
As fixing devices, fixing devices 1 to 6 having the following configurations were used.
[Fixing machine 1]
The fixing belt of the fixing device 1 was produced as follows. A primer (DY39-067 manufactured by Dow Corning Toray Co., Ltd.) was formed on the outer periphery of a cylindrical endless film base made of polyimide with a thickness of 90 μm by spray coating and dried at room temperature. Thereafter, two-component addition type liquid silicone rubber (DY35-2083 manufactured by Toray Dow Corning Silicone Co., Ltd.) was mixed with two components and diluted with toluene in an appropriate amount. This solution was applied by spray coating to a thickness of 200 μm, cured at 120 ° C. for 10 minutes, and then secondarily cured at 200 ° C. for 4 hours to form an elastic layer. Next, a primer (PR-990CL manufactured by Mitsui DuPont Fluorochemical Co., Ltd.) was spray-coated at a thickness of 4 μm and then dried at 150 ° C. for 30 minutes. Thereafter, the ratio of the number of oxygen atoms / number of carbon atoms in the molecular chain is 1/60 or more and the average particle size is 10 μm PFA (PFA-950HPPlus manufactured by Mitsui DuPont Fluorochemical Co.), and the average particle size is 0.1 μm. 2% of carbon black was added to the mixed dispersion of PFA and spray-coated with a thickness of 30 μm. Thereafter, firing was performed at 340 ° C. for 30 minutes (melting PFA particles) to form a release layer, and a fixing belt of the fixing device 1 was obtained. This fixing belt was incorporated in the fixing device (40) and used as the fixing device 1.

[Fixing machine 2]
The fixing belt of the fixing machine 2 is a PFA having a ratio of the number of oxygen atoms / number of carbon atoms in the molecular chain of 1/60 or more and an average particle diameter of 10 μm on the elastic layer of the fixing machine 1 and the created elastic layer (Mitsui, A mixed dispersion of PFA-950HP Plus manufactured by DuPont Fluorochemical Co., Ltd.) and the same PFA having an average particle size of 0.1 μm was spray-coated and baked to obtain a fixing belt of the fixing device 2. Other conditions such as the thickness of the release layer are the same as those of the fixing device 1. This fixing belt was incorporated in the fixing device (40) and used as the fixing device 2.

[Fixing machine 3]
The fixing belt of the fixing machine 3 is a PFA having a ratio of the number of oxygen atoms / number of carbon atoms in the molecular chain of 1/60 or more and an average particle diameter of 10 μm on an elastic layer formed in the same manner as the elastic layer of the fixing machine 1. 4% carbon black is added to a mixed dispersion of PFA-950HP Plus (Mitsui / DuPont Fluorochemical Co., Ltd.) and the same PFA with an average particle size of 0.1 μm, spray coated, baked, and fixing belt of fixing device 3 Got. Other conditions such as the thickness of the release layer are the same as those of the fixing device 1. This fixing belt was incorporated in the fixing device (40) and used as the fixing device 3.

[Fixing machine 4]
The fixing belt of the fixing device 4 is formed on the elastic layer formed in the same manner as the elastic layer of the fixing device 1 by using a PFA having a ratio of the number of oxygen atoms / number of carbon atoms in the molecular chain of 1/100 or less and an average particle size of 10 μm. Add 2% carbon black to the mixed dispersion of PFA-350J (Mitsui / DuPont Fluorochemical Co., Ltd.) and the same PFA with an average particle size of 0.1 μm, spray coat, fire, and fix the fixing belt of the fixing machine 4 Obtained. Other conditions such as the thickness of the release layer are the same as those of the fixing device 1. This fixing belt was incorporated in the fixing device (40) and used as the fixing device 4.

[Fixing machine 5]
The fixing belt of the fixing device 5 is a PFA having a ratio of the number of oxygen atoms / number of carbon atoms in the molecular chain of 1/60 or more and an average particle diameter of 10 μm on an elastic layer prepared in the same manner as the elastic layer of the fixing device 1. Add 4.7% carbon black to a mixed dispersion of PFA-950HP Plus (Mitsui / DuPont Fluorochemical Co., Ltd.) and the same PFA with an average particle size of 0.1 μm, spray coat, fire, and fixer 5 A fixing belt was obtained. Other conditions such as the thickness of the release layer are the same as those of the fixing device 1. This fixing belt was incorporated in the fixing device (40) and used as the fixing device 5.

[Fixing machine 6]
The fixing belt of the fixing device 6 is a PFA having a ratio of the number of oxygen atoms / number of carbon atoms in the molecular chain of 1/60 or more and an average particle diameter of 10 μm on an elastic layer prepared in the same manner as the elastic layer of the fixing device 1. 2.7% carbon black was added to a mixed dispersion of PFA-950HP Plus (Mitsui / DuPont Fluorochemical Co., Ltd.) and the same PFA with an average particle size of 0.1 μm, and after spray coating, firing was performed. A fixing belt was obtained. Other conditions such as the thickness of the release layer are the same as those of the fixing device 1. This fixing belt was incorporated in the fixing device (40) and used as the fixing device 6.

Glossiness evaluation method:
Adjustment was made so that 1.0 ± 0.1 mg / cm ² of toner was developed, and the glossiness of the solid image sample when the surface temperature of the fixing roller was 160 ° C. was determined by a gloss meter manufactured by Nippon Denshoku Industries Co., Ltd. Was measured under the condition of an incident angle of 60 °.
The transfer paper used was Ricoh full color PPC paper type 6000 <70W. As the glossiness is higher, the glossiness is higher, and a glossiness of about 10% or more is required to obtain a clear image with excellent color reproducibility.

Offset property evaluation method:
The temperature of the fixing roller was changed by 5 ° C., and the temperature at which offset started to occur was measured. The fixing roller was evaluated under the condition that no oil was applied, and the transfer paper was Ricoh Full Color PPC paper type 6000 <70 W. The evaluation results were expressed as follows.

Low temperature fixability:
The fixing temperature was changed by the same method as the evaluation of the offset property, and a copy image was obtained such that the image density by the Macbeth densitometer was 1.2.
The copy image at each temperature was rubbed 10 times with a clock meter equipped with a sand eraser, the image density before and after that was measured, and the fixing rate was determined by the following formula.
Fixing rate (%) = (Image density after 10 times of sand eraser) / (Previous image density) × 100
The temperature at which a fixing rate of 70% or more was achieved was defined as the minimum fixing temperature.
The fixing roller was evaluated under the condition that no oil was applied, and the transfer paper was Ricoh Full Color PPC paper type 6000 <70W.

Flexibility evaluation method;
The bending resistance was evaluated as follows. The fixing belts of Examples and Comparative Examples were each incorporated in the fixing device (40) described above, and evaluation was performed by visually checking the release layer for cracks after outputting 300,000 sheets. “◯” indicates that there is no crack, “Δ” indicates that there is a slight crack that does not become an abnormal image, and “×” indicates that a crack that causes an abnormal image has occurred.

Chile, electrostatic offset evaluation method;
As for the dust and electrostatic offset of the toner image on the transfer material, the fixing belts of the example and the comparative example are incorporated in the fixing device (40) described above, and the image is output in a low temperature and low humidity environment of 10 ° C. and 15% RH. The output image was evaluated by visual confirmation. Chilli and those with no offset were marked with “O”, and those with confirmed dust and offset were marked with “X”.
Table 5 shows toners and fixing conditions of Examples and Comparative Examples.

評価結果を表６、表７に示す

The evaluation results are shown in Table 6 and Table 7.

1 is a diagram illustrating an example of an image forming apparatus according to the present invention. It is a diagram illustrating a belt-type fixing device. FIG. 3 is a diagram illustrating a cross section of a fixing belt. The relationship between the addition amount of carbon black and the bending resistance is such that the ratio of the number of oxygen atoms / carbon atoms in the molecular chain is 1/60 or more and the ratio of oxygen atoms / carbon atoms in the molecular chain is 1. It is the figure investigated about the bending resistance of PFA below / 100. It is the figure of the data which showed the flow curve of the flow tester used by this invention.

Explanation of symbols

P Transfer paper 1Y Yellow photosensitive drum 1M Magenta photosensitive drum 1C Cyan photosensitive drum 1Bk Black photosensitive drum 2Y Yellow charger 2M Magenta charger 2C Cyan charger 2Bk Black charger 3Y Yellow exposure device 3M Magenta exposure device 3C Cyan exposure Device 3Bk black exposure device 4Y yellow developing device 4M magenta developing device 4C cyan developing device 4Bk black developing device 5Y yellow transfer device 5M magenta transfer device 5C cyan transfer device 5Bk black transfer device 6Y yellow photoconductor cleaner 6M magenta photoconductor cleaner 6C cyan photoconductor Body cleaner 6Bk black photoreceptor cleaner 7 driving roller 8 driven roller 10Y yellow image forming unit 10M magenta image forming unit 10C cyan image forming unit 10Bk black image forming unit G 20 Conveying belt 30 Paper feed means 40 Fixing device 41 Fixing roller 42 Pressure roller 43 Spring 44 Heating roller 45 Fixing belt 46 Halogen lamp 47 Tension roller 48 Spring 49 Thermistor 50 Paper feed tray 451 Film base 452 Elastic layer 453 Release layer

Claims (20)

An image forming apparatus having a fixing unit for fixing a toner image on a recording medium by heat and pressure, wherein the toner for forming the toner image contains crystalline polyester (A), and the fixing unit The surface layer in contact with the toner image of the fixing rotator is made of a fluororesin, and the surface layer has the number of oxygen atoms / number of carbon atoms in the molecular chain. The main component is a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (PFA) having a ratio of 1/60 or more, and the surface resistivity is 1 × 10 ⁸ to 1 × 10 ¹¹ Ω / □. An image forming apparatus.   The image forming apparatus according to claim 1, wherein a fixing nip time of the fixing unit is 30 to 100 msec. The image forming apparatus according to claim 1, wherein a fixing pressure of the fixing unit is 0.5 to 4 kgf / cm ² .   The weight average particle diameter of the toner is 3 to 8 μm, and the ratio (D4 / D1) of the weight average particle diameter (D4) to the number average particle diameter (D1) is in the range of 1.00 to 1.40. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.   The apparatus according to any one of claims 1 to 4, wherein the apparatus is used in an image forming method for forming a multicolor image by superimposing toner images of different colors, and the toner is a full color toner. Image forming apparatus. The surface layer in contact with the toner image of the fixing rotator comprises a plurality of types of PFA having different particle diameters and at least one conductive filler selected from carbon black, metal, or metal oxide. the image forming apparatus according to any one of claims 1 to 5. The image forming apparatus according to any one of claims 1 to 6 wherein the glass transition point of the polyester resin (A) is characterized in that in the range of 80 to 130 ° C.. The content of the polyester resin (A) in the binder resin of the toner is 3 to 75% by weight, and the volume specific resistance value LogR of the toner is 10.5 to 11.2 LogΩ · cm. The image forming apparatus according to any one of 1 to 7 . The toner is a toner for electrostatic charge development which contains a release agent, in any one of claims 1 to 8, characterized in that the releasing agent is one having a glass transition point of 70 to 90 ° C. The image forming apparatus described. The image forming apparatus according to claim 9 , wherein the release agent is one or more selected from de-free fatty acid type carnauba wax, polyethylene wax, montan wax, and oxidized rice wax. An image forming fixing device for fixing a toner image on a recording medium by heat and pressure, wherein the toner for forming the toner image contains crystalline polyester (A), and the fixing device The surface layer in contact with the toner image of the fixing rotator is a member made of a fluororesin, and the surface layer has a ratio of the number of oxygen atoms / number of carbon atoms in the molecular chain. The main component is 1/60 or more tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (PFA), and the surface resistivity is 1 × 10 ⁸ to 1 × 10 ¹¹ Ω / □. A fixing device. The fixing device according to claim 11 , wherein a fixing nip time of the fixing device is 30 to 100 msec. The fixing device according to claim 11 or 12 fixing pressure of the fixing device is characterized in that it is a 0.5~4kgf / cm ^2. The weight average particle diameter of the toner is 3 to 8 μm, and the ratio (D4 / D1) of the weight average particle diameter (D4) to the number average particle diameter (D1) is in the range of 1.00 to 1.40. the fixing device according to any one of claims 11 to 13, characterized. Different colors are fixing apparatus used in an image forming that forms a multicolor image by superimposing toner images of, and the toner according to any one of claims 11 to 14, characterized in that a full-color toner Fixing device. The surface layer in contact with the toner image of the fixing rotator comprises a plurality of types of PFA having different particle diameters and at least one conductive filler selected from carbon black, metal, or metal oxide. the fixing device according to any one of claims 11 to 15. The fixing device according to any one of claims 11 to 16 wherein the glass transition point of the polyester resin (A) is characterized in that in the range of 80 to 130 ° C.. 11 through claim content of the polyester resin (A) in the binder resin is 3-75 wt%, and the volume resistivity LogR of the toner is characterized in that it is a 10.5~11.2LogΩ · cm The fixing device according to any one of 17 . The toner is a toner for electrostatic charge development which contains a release agent, to any one of claims 11 to 18, wherein the release agent is one having a glass transition point of 70 to 90 ° C. The fixing device described. The fixing device according to claim 19 , wherein the release agent is one or more selected from a de-free fatty acid type carnauba wax, a polyethylene wax, a montan wax, and an oxidized rice wax.

Images