JP2020052141A - Image forming apparatus - Google Patents

Abstract

To provide an image forming apparatus that reduces the amount of emission of UFPs to the outside of the apparatus.SOLUTION: An image forming apparatus comprises: an image holding body; charging means; electrostatic charge image forming means; developing means that stores a developer containing a toner including toner particles containing a mold release agent having a melting temperature of 60°C or more and 100°C or less, and develops an electrostatic charge image formed on the image holding body with the developer to form a toner image; transfer means; fixing means that includes a rotating body pair forming a contact area with a belt member and a rotating body, and inserts a recording medium to which the toner image is transferred into the contact area to heat-fix the toner image; and an air supply pipe that includes an air supply inlet provided around the upstream of the contact area and an air supply outlet provided downstream of the contact area and around a conveyance path of the recording medium, connects the air supply inlet with the air supply outlet through an inner peripheral side of the belt member, and exhausts air entering from the air supply inlet toward the recording medium from the air supply outlet.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an image forming apparatus.

  In the formation of an image by electrophotography, for example, after charging the surface of an image carrier, an electrostatic image is formed on the surface of the image carrier in accordance with image information, and then the electrostatic image is developed using toner. The toner image is formed by developing with a developer, and the toner image is transferred and fixed on the surface of the recording medium.

  For example, Japanese Patent Application Laid-Open No. H11-163873 discloses "a fixing unit for fixing toner on a sheet, a curved section in which a sheet conveying path provided downstream of the fixing section in the sheet conveying direction is curved and extends in the conveying direction, A duct whose opening is opened and arranged radially outside of the curved portion of the paper transport path and extends in a paper width direction crossing the paper transport direction, and a duct of the duct for generating an airflow inside the duct. An image forming apparatus comprising two fans provided adjacent to an air inlet and arranged side by side in the sheet width direction and having the air intake side directed toward the fixing unit.

  Japanese Patent Application Laid-Open No. H11-163873 discloses a nip section between a first rotating body that contacts and heats an unfixed toner image formed on a sheet using a toner containing a release agent, and the first rotating body. A second rotator that sandwiches and conveys the sheet, a cover member that covers an outer surface of the first rotator with a gap, a fan, and air generated by the fan. And a duct leading toward an end, wherein the cover member extends from near the sheet entrance of the nip to the duct.

  Japanese Patent Application Laid-Open No. H11-163,199 discloses that a fixing member having a heating unit, a pressing member that forms a nip portion where a sheet holding a toner image in contact with the fixing member is sandwiched, and a pressing member near a paper outlet of the nip portion. A blower duct having a discharge port opened toward the air, a blower means for discharging air to the vicinity of the paper outlet via the blower duct, and a paper discharged from the nip disposed above the paper conveyance path. And a guide unit having a guide member for guiding the sheet, wherein the fixing unit fixes the toner image on the sheet by conveying the sheet holding the toner image in the nip portion while heating and pressing the sheet, and fixing the toner image on the sheet. A fixing device having an urging means for urging the paper toward the guide member in the vicinity of the fixing device is disclosed.

JP 2017-134103 A JP-A-2006-075781 JP 2011-209504 A

  In recent years, there has been a demand for a toner having excellent low-temperature fixability due to a demand for energy saving, and has toner particles containing a release agent having a low melting temperature (for example, a release agent having a melting temperature of 100 ° C. or lower). Toner is used. However, when a toner containing a release agent having a low melting temperature is used and a toner image is formed by performing fixing using the above-described fixing unit, particles derived from the vaporized release agent are located upstream of the contact area in the fixing unit. It has been found that particles having a diameter of 100 nm or less (so-called UFP; Ultra-Fine Particle) tend to be easily generated.

Therefore, the vicinity of the contact area on the upstream side in the recording medium transport direction of the contact area in the fixing unit and the periphery of the recording medium transport path on the downstream side in the recording medium transport direction of the contact area are connected by an air supply pipe, and the upstream side of the contact area is connected. A method is conceivable in which the generated particles (UFP) are sent downstream through an air supply pipe and exhausted from the outlet of the air supply pipe toward a recording medium.
However, when particles (UFP) having a particle diameter of 100 nm or less pass through the air supply pipe, they may cool and solidify and adhere to the inside of the air supply pipe. In addition, the solidified particles (UFP) adhered to the inside of the air supply pipe may form a larger lump and hinder air supply.
Therefore, it is required to suppress the adhesion of the solidified particles (UFP) having a particle size of 100 nm or less to the inside of the air supply pipe.

  An object of the present invention is to record a toner image formed by a developer containing toner having toner particles containing a release agent having a melting temperature of 60 ° C. or more and 100 ° C. or less and transferred to a first surface of a recording medium. As a fixing unit for fixing to the first surface of the medium, a belt member having an outer peripheral surface in contact with the first surface of the recording medium and a rotator pair having a rotator contacting the outer peripheral surface of the belt member to form a contact area are provided. An image forming apparatus provided with a fixing unit for inserting and heating a recording medium onto which a toner image has been transferred through a contact area, wherein the contact area is located upstream of the contact area in the recording medium transport direction and on the first surface side of the recording medium. And an air supply inlet provided around the recording medium, and an air supply outlet provided around the conveyance path of the recording medium on the downstream side of the contact area in the recording medium conveyance direction and on the first surface side of the recording medium. Gas from the inlet An air supply pipe that exhausts air from the air supply outlet toward the recording medium, and has a particle diameter of 100 nm or less as compared with a case where the air supply pipe connects the air supply inlet and the air supply outlet through the outer peripheral side of the belt member. It is an object of the present invention to provide an image forming apparatus in which the solidification of (UFP) is prevented from adhering to the inside of an air supply pipe.

  The above problem is solved by the following means.

<1>
An image carrier,
Charging means for charging the surface of the image holding member,
Electrostatic image forming means for forming an electrostatic image on the surface of the charged image carrier,
A developer containing a toner having toner particles containing a release agent having a melting temperature of 60 ° C. or more and 100 ° C. or less is contained, and the developer is used to develop an electrostatic charge image formed on the surface of the image holding member. Developing means for forming an image;
Transfer means for transferring the toner image to a first surface of a recording medium;
A belt member for bringing an outer peripheral surface into contact with the first surface of the recording medium; and a rotating body pair having a rotating body that forms a contact area by contacting the outer peripheral surface of the belt member, wherein the toner image is transferred. Fixing means for inserting and heating the recording medium through the contact area, and fixing the toner image on the first surface;
On the upstream side of the contact area in the recording medium transport direction and on the first surface side of the recording medium, an air supply inlet provided around the contact area, and on the downstream side of the contact area in the recording medium transport direction and the On the first surface side of the recording medium, there is provided an air supply outlet provided around a conveyance path of the recording medium, and the air supply inlet and the air supply outlet are connected through an inner peripheral side of the belt member. An air supply pipe that exhausts gas that has entered from the air supply inlet toward the recording medium from the air supply outlet,
An image forming apparatus comprising:
<2>
The image forming apparatus according to <1>, wherein a melting temperature of the release agent in the toner particles is from 60 ° C to 90 ° C.
<3>
The image forming apparatus according to <1> or <2>, wherein the release agent in the toner particles is paraffin wax.
<4>
The image forming apparatus according to any one of <1> to <3>, wherein the toner particles include a crystalline resin.
<5>
The image forming apparatus according to <4>, wherein the content of the crystalline resin is 3% by mass or more and 20% by mass or less based on the mass of the toner particles.
<6>
The image forming apparatus according to <5>, wherein the content of the crystalline resin is 5% by mass or more and 15% by mass or less based on the mass of the toner particles.
<7>
The image forming apparatus according to any one of <1> to <6>, wherein the toluene insoluble content of the toner particles is 25% by mass or more and 40% by mass or less.
<8>
The image forming apparatus according to any one of <1> to <7>, wherein the shape factor SF1 of the toner particles is 140 or more.
<9>
The image forming apparatus according to any one of <1> to <8>, wherein the rotating body is a roll member.
<10>
The image forming apparatus according to any one of <1> to <9>, wherein the belt member is a belt member having a polyimide resin layer.
<11>
The image forming apparatus according to any one of <1> to <10>, wherein the belt member is a heating belt member that heats the toner image.
<12>
<11> The image forming apparatus according to <11>, further comprising: a heating member that contacts and heats the belt member on the inner peripheral surface side of the belt member, and wherein the air supply pipe is disposed above the heating member in the direction of gravity. apparatus.
<13>
The image forming apparatus according to any one of <1> to <12>, wherein a maximum diameter of a portion passing through an inner peripheral side of the belt member in the air supply pipe is 2 mm or more and 10 mm or less.
<14>
The image forming apparatus according to any one of <1> to <13>, wherein a set fixing temperature of the pair of rotating members is 100 ° C. or more and 200 ° C. or less.
<15>
The image forming apparatus according to <14>, wherein a set fixing temperature of the pair of rotating members is from 120 ° C to 200 ° C.
<16>
<14> or a difference [T1-T2] between a fixing set temperature [T1] in the rotating body pair and a melting temperature [T2] of the release agent in the toner particles is 40 ° C. or more and 120 ° C. or less. The image forming apparatus according to <15>.

According to the invention according to <1> or <9>, the first surface of the recording medium is formed of a developer including toner having toner particles including a release agent having a melting temperature of 60 ° C or higher and 100 ° C or lower. As a fixing means for fixing the toner image transferred to the recording medium to the first surface of the recording medium, a belt member for bringing the outer peripheral surface into contact with the first surface of the recording medium, and a contact area being formed by contacting the outer peripheral surface of the belt member An image forming apparatus, comprising: a rotating member pair having a rotating member to be rotated; and a fixing unit for inserting the recording medium onto which the toner image has been transferred into the contact area and heating the recording medium. On the first surface side, an air supply inlet provided around the contact region, and on the first surface side of the recording medium downstream of the contact region in the recording medium transport direction and around the recording medium transport path. Connect the air supply outlet, An air supply pipe that exhausts gas entering from the air inlet toward the recording medium from the air supply outlet, compared with a case where an air supply pipe that connects the air supply inlet and the air supply outlet through the outer peripheral side of the belt member is provided. The present invention provides an image forming apparatus in which the coagulation of particles (UFP) having a particle diameter of 100 nm or less is suppressed from adhering to the inside of an air supply pipe.
According to the invention according to <2>, the toner image formed by the developer including the toner having the toner particles including the release agent and transferred to the first surface of the recording medium is transferred onto the first surface of the recording medium. As a fixing unit for fixing, a belt member for bringing the outer peripheral surface into contact with the first surface of the recording medium, and a rotating body pair having a rotating body that contacts the outer peripheral surface of the belt member to form a contact area are provided, and the toner image is transferred. An image forming apparatus provided with a fixing unit that inserts the heated recording medium into the contact area and heats the recording medium, and is provided around the contact area on the upstream side of the contact area in the recording medium conveyance direction and on the first surface side of the recording medium. At the air supply inlet, and at the downstream side of the contact area in the recording medium conveyance direction and on the first surface side of the recording medium, the air supply outlets provided around the conveyance path of the recording medium are connected, and the gas entering from the air supply inlet is connected. From air supply outlet to recording medium The air release pipe that connects the air supply inlet and the air supply outlet through the outer peripheral side of the belt member, and the melting temperature of the release agent is 60 ° C. or more and 90 ° C. or less, Even in this case, there is provided an image forming apparatus in which the adhesion of the coagulated particles of particles having a particle size of 100 nm or less (UFP) to the inside of the air supply pipe is suppressed.
According to the invention according to <3>, the toner formed by the developer including the toner having the toner particles including the release agent having the melting temperature of 60 ° C. or more and 100 ° C. or less and transferred to the first surface of the recording medium As a fixing unit for fixing an image on the first surface of the recording medium, the fixing device includes a belt member that makes the outer peripheral surface contact the first surface of the recording medium, and a rotating body that contacts the outer peripheral surface of the belt member to form a contact area. In an image forming apparatus including a pair of rotating members, and a fixing unit that inserts a recording medium onto which a toner image is transferred into a contact area and heats the recording medium, an upstream side of the contact area in a recording medium conveyance direction and a first surface side of the recording medium And an air supply inlet provided around the contact area, and an air supply outlet provided around the conveyance path of the recording medium downstream of the contact area in the recording medium conveyance direction and on the first surface side of the recording medium. From the air inlet Release air from the air supply outlet toward the recording medium through the outer peripheral side of the belt member to connect the air supply inlet and the air supply outlet. Even if the agent is paraffin wax, there is provided an image forming apparatus in which coagulation of particles (UFP) having a particle size of 100 nm or less is suppressed from adhering to the inside of an air supply pipe.
According to the invention according to <4>, <5> or <6>, the recording medium is formed of a developer including toner having toner particles including a release agent having a melting temperature of 60 ° C or higher and 100 ° C or lower. As a fixing unit for fixing the toner image transferred on the first surface to the first surface of the recording medium, a belt member for bringing the outer peripheral surface into contact with the first surface of the recording medium, and a belt member for making contact with the outer peripheral surface of the belt member. An image forming apparatus including a rotating body pair having a rotating body that forms an area, and a fixing unit that inserts and heats the recording medium onto which the toner image has been transferred into the contact area, and is located upstream of the contact area in the recording medium transport direction. In addition, on the first surface side of the recording medium, an air supply inlet provided around the contact area, and on the downstream side of the contact area in the recording medium transport direction and on the first surface side of the recording medium, around the transport path of the recording medium. Connect the provided air outlet An air supply pipe that exhausts gas entering from the air supply inlet toward the recording medium from the air supply outlet, and includes an air supply pipe that connects the air supply inlet and the air supply outlet through the outer peripheral side of the belt member. As compared with the case, even when the toner particles include a crystalline resin, an image forming apparatus is provided in which the adhesion of the coagulated particles of particles having a particle size of 100 nm or less (UFP) to the inside of the air supply pipe is suppressed.
According to the invention according to <7>, adhesion of the coagulated product of particles (UFP) having a particle size of 100 nm or less to the inside of the air supply pipe is suppressed as compared with the case where the toluene insoluble content of the toner particles is less than 25% by mass. An image forming apparatus is provided.
According to the invention according to <8>, the toner formed by the developer including the toner having the toner particles including the release agent having the melting temperature of 60 ° C. or more and 100 ° C. or less and transferred to the first surface of the recording medium As a fixing unit for fixing an image on the first surface of the recording medium, the fixing device includes a belt member that makes the outer peripheral surface contact the first surface of the recording medium, and a rotating body that contacts the outer peripheral surface of the belt member to form a contact area. In an image forming apparatus including a pair of rotating members, and a fixing unit that inserts a recording medium onto which a toner image is transferred into a contact area and heats the recording medium, an upstream side of the contact area in a recording medium conveyance direction and a first surface side of the recording medium And an air supply inlet provided around the contact area, and an air supply outlet provided around the conveyance path of the recording medium downstream of the contact area in the recording medium conveyance direction and on the first surface side of the recording medium. From the air inlet A gas supply pipe for exhausting the collected gas from the air supply outlet toward the recording medium, wherein the toner particles are compared with a case where the air supply pipe connects the air supply inlet and the air supply outlet through the outer peripheral side of the belt member. Even if the shape factor SF1 is 140 or more, there is provided an image forming apparatus in which the coagulation of particles (UFP) having a particle size of 100 nm or less is suppressed from adhering to the inside of an air supply pipe.

According to the invention according to <10>, a coagulated product of particles (UFP) having a particle diameter of 100 nm or less as compared with a case where the belt member is not provided with the polyimide resin layer and is provided with a metal layer for an IH heating system. An image forming apparatus is provided in which the adhesion of the toner to the inside of the air supply pipe is suppressed.
According to the invention according to <11>, the particle diameter is 100 nm or less as compared with the case where the belt member is not the member that plays the role of heating the toner image, but the rotating body that contacts the belt member is the heating member that heats the toner image. An image forming apparatus is provided, in which the coagulation of particles of UFP (UFP) is prevented from adhering to the inside of an air supply pipe.
According to the invention according to <12>, compared to a case where a heating member that contacts and heats the belt member is provided only on the outer peripheral surface side of the belt member, the inside of the air supply pipe of the coagulated product of particles (UFP) having a particle diameter of 100 nm or less is provided. Provided is an image forming apparatus in which adhesion to an image is suppressed.
According to the invention according to <13>, compared to the case where the maximum diameter of the portion of the air supply pipe passing through the inner peripheral side of the belt member is more than 10 mm, the inside of the air supply pipe of the coagulated product of particles (UFP) having a particle diameter of 100 nm or less is provided. Provided is an image forming apparatus in which adhesion to an image is suppressed.
According to the invention according to <14> or <15>, compared with the case where the set fixing temperature in the rotating body pair is higher than 200 ° C., the coagulated product of particles (UFP) having a particle diameter of 100 nm or less is supplied to the inside of the air supply pipe. An image forming apparatus with reduced adhesion is provided.
According to the invention according to <16>, the difference [T1-T2] between the fixing set temperature [T1] in the rotating body pair and the melting temperature [T2] of the release agent in the toner particles is larger than the case where the difference [T1-T2] is more than 120 ° C. The present invention provides an image forming apparatus in which the coagulation of particles (UFP) having a particle diameter of 100 nm or less is suppressed from adhering to the inside of an air supply pipe.

FIG. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an embodiment. FIG. 2 is a schematic configuration diagram illustrating an example of a fixing device and an air supply pipe included in the image forming apparatus according to the embodiment. FIG. 3 is a schematic perspective view of a fixing device and an air supply pipe shown in FIG. 2. FIG. 3 is a schematic perspective view of a fixing device and an air supply pipe shown in FIG. 2. FIG. 3 is a schematic plan view of a fixing device and an air supply pipe illustrated in FIG. 2.

  Hereinafter, an embodiment which is an example of the present invention will be described in detail.

<Image forming apparatus>
The image forming apparatus according to the present exemplary embodiment includes an image carrier, a charging unit that charges a surface of the image carrier, an electrostatic image forming unit that forms an electrostatic image on the surface of the charged image carrier, and a developer. And a developing unit for developing the electrostatic image formed on the surface of the image holding member with a developer to form a toner image, a transfer unit for transferring the toner image to a first surface of a recording medium, and a toner image. And a fixing unit for fixing the recording medium to the first surface of the recording medium.
The developer contained in the developing means includes toner having toner particles containing a release agent having a melting temperature of 60 ° C. or more and 100 ° C. or less.
The fixing unit includes a belt member that makes the outer peripheral surface contact the first surface of the recording medium (hereinafter, also simply referred to as a “toner image surface”), and a contact area (hereinafter, simply “nip”) that comes into contact with the outer peripheral surface of the belt member. (Hereinafter also referred to as a rotator) that forms a rotator, and a fixing member that fixes the toner image on the first surface by heating the recording medium on which the toner image has been transferred by inserting the recording medium onto the contact area (nip). .
In the present embodiment, an air supply inlet provided around the contact area (nip) on the upstream side of the contact area (nip) in the recording medium transport direction and on the first surface (toner image surface) side of the recording medium. An air outlet provided around the conveyance path of the recording medium on the downstream side of the contact area (nip) in the recording medium conveyance direction and on the first surface (toner image surface) side of the recording medium; An air supply pipe that connects the air supply inlet and the air supply outlet through the side and exhausts gas that has entered from the air supply inlet toward the recording medium through the air supply outlet.

In the following description, a toner for developing an electrostatic image having toner particles containing a release agent having a melting temperature of 60 ° C. or more and 100 ° C. or less may be referred to as “specific toner”.
In the following description, "upstream" refers to the upstream side in the recording medium transport direction, and "downstream" refers to the downstream side in the recording medium transport direction.

2. Description of the Related Art In recent years, image forming apparatuses have adopted a technique of fixing toner at a low temperature in order to reduce power consumption when fixing a toner image in response to a demand for energy saving. For example, in order to improve the low-temperature fixability, the developer contained in the developing unit of the image forming apparatus contains a release agent having a low melting temperature (for example, a release agent having a melting temperature of 100 ° C. or lower). Toner containing toner particles may be used.
However, when an image is formed using a toner containing a release agent having a low melting temperature, the release agent has a low melting temperature when the toner image is heated and fixed to a recording medium by a fixing unit. It was found that the amount of the release agent to be vaporized tended to be large, especially on the upstream side of the nip.
For that reason, the ease of vaporization of the release agent on the upstream and downstream sides of the nip is compared. In the rotating body pair in the fixing unit, heat is applied to the toner image on the recording medium from at least one of the rotating bodies. Since the surface temperature of the rotating body decreases from the point of contact with the recording medium (or the toner image held thereon), the surface temperature of the rotating body in the nip is higher as it is closer to the upstream side, that is, the nip. Among them, the surface temperature of the rotating body is highest at the upstream end. Therefore, in the nip, the highest temperature is applied to the toner image when the toner is inserted into the upstream end, and the amount of the release agent vaporized in the upstream of the nip is larger than that in the downstream. It is considered easy. Further, when the recording medium contains moisture (for example, when the recording medium is paper), the release agent is liable to be vaporized with the vaporization of the water. Therefore, it is considered that the vaporization of moisture from the recording medium is more likely to occur on the upstream side in the nip where the heating is performed first than on the downstream side, and the amount of the release agent vaporized tends to increase.

The release agent vaporized as described above is re-coagulated in the air to form particles having a particle diameter of 100 nm or less (so-called “UFP (ultra fine particles)”) derived from the vaporized release agent. Then, the generated particles may be discharged to the outside of the image forming apparatus.
Therefore, it is required to reduce the discharge amount of particles (UFP) having a particle diameter of 100 nm or less out of the apparatus.

  On the other hand, in the image forming apparatus according to the present embodiment, the air supply inlet is provided on the upstream side of the nip and around the nip on the first surface (toner image surface) side of the recording medium, and is provided on the downstream side of the nip and on the recording medium. An air supply pipe having an air supply outlet is provided around the recording medium conveyance path on the first surface (toner image surface) side. Therefore, particles (UFP) having a particle diameter of 100 nm or less derived from the vaporized release agent and generated at the upstream side of the nip of the rotating body pair enter the air supply pipe from the air supply inlet together with the surrounding air. Thereafter, the particles (UFP) are transported together with the air to the air supply outlet, and are exhausted from the air supply outlet toward the recording medium. The particles (UFP) that have arrived on the recording medium adhere to the surface of the toner image or an area where the toner image does not exist on the surface of the recording medium, and are conveyed to the outside of the apparatus together with the recording medium while being fixed on the recording medium. That is, the particles (UFP) generated from the release agent in the toner image are returned to and adhered to the recording medium through the air supply pipe, so that the particles (UFP) float in the air and are directly discharged out of the apparatus. It is considered that this is suppressed.

However, if the air supply pipe has a configuration in which the air supply inlet and the air supply outlet are connected through a position distant from the rotating body pair, particles (UFP) having a particle size of 100 nm or less passing through the air supply pipe cool and solidify. And may adhere to the inside of the air duct. Then, the coagulated particles (UFP) having a particle diameter of 100 nm or less attached to the inside of the air supply pipe become a larger lump, and as a result, may hinder air supply.
Therefore, it is required to suppress the adhesion of the solidified particles (UFP) having a particle size of 100 nm or less to the inside of the air supply pipe.

  On the other hand, the image forming apparatus according to the present embodiment has a configuration in which the air supply pipe connects the air supply inlet and the air supply outlet through the inner peripheral side of the belt member forming the rotating body pair. That is, the air supply pipe has a configuration in which a part of the air supply pipe is surrounded by the belt member. In the portion surrounded by the belt member, the air supply pipe is heated by radiant heat from the belt member. When a member for heating the belt member is provided on the inner peripheral surface side of the belt member, the air supply pipe is also heated by heat from the heating member. As a result, the air inside the air supply pipe is also warmed, so that the particles (UFP) passing through the air supply pipe are cooled, solidified, and prevented from adhering to the inside of the air supply pipe. Then, it is considered that the coagulated UFP adhered to the inside of the air supply pipe becomes a larger lump, thereby preventing the air supply from obstructing the air supply.

  In the present embodiment, as described above, adhesion of coagulated particles (UFP) having a particle size of 100 nm or less to the inside of the air supply pipe is suppressed.

  Here, "around the contact area" where the air supply inlet is provided is defined as a vapor generated from a toner image, a recording medium or the like in the contact area (nip) and floating on the upstream side, and the vaporized substance. It indicates the range from the air supply inlet to the distance that can take in particles and the like generated by re-solidification. By providing the air supply inlet in this range, the release agent in the toner image is vaporized and re-solidified in the contact area (nip), and the UFP floating on the upstream side of the contact area is generated from the air supply inlet. It is captured.

  Further, “around the conveyance path of the recording medium” where the air supply outlet is provided means that the UFP contained in the air exhausted from the air supply outlet toward the recording medium is the surface of the toner image on the recording medium and the recording medium. It indicates a range up to a distance at which the toner can adhere to an area having no toner image on the surface. By providing the air supply outlet in this range, the UFP exhausted toward the recording medium adheres to the recording medium and is transported to the outside of the apparatus together with the recording medium in a state where the UFP is fixed to the recording medium. And is discharged to the outside of the apparatus as it is.

  Hereinafter, the configuration of the image forming apparatus according to the present embodiment will be described in detail.

Here, the image forming apparatus according to the present embodiment is an apparatus of a direct transfer system for directly transferring the toner image formed on the surface of the image carrier to a recording medium; Intermediate transfer type device for primary transfer to the surface of the transfer member and secondary transfer of the toner image transferred to the surface of the intermediate transfer member to the surface of the recording medium; after transfer of the toner image and before charging, the surface of the image carrier A well-known image forming apparatus such as an apparatus provided with a static eliminator for irradiating static elimination light to the surface is applied.
In the case of an intermediate transfer type device, the transfer device includes, for example, an intermediate transfer body on which a toner image is transferred on the surface, and a primary transfer for primarily transferring the toner image formed on the surface of the image holding body to the surface of the intermediate transfer body. A configuration including a member and a secondary transfer member that secondary-transfers the toner image transferred on the surface of the intermediate transfer member onto the surface of the recording medium is applied.

  Note that, in the image forming apparatus according to the present embodiment, for example, a portion including at least the image holding member may have a cartridge structure (process cartridge) that is detachable from the image forming apparatus.

  Here, the configuration of the image forming apparatus according to the present embodiment will be described with reference to the drawings.

FIG. 1 is a schematic configuration diagram illustrating a configuration of an example of an image forming apparatus according to the present embodiment.
As shown in FIG. 1, the image forming apparatus 10 according to the present embodiment is, for example, an intermediate transfer type image forming apparatus generally called a tandem type. Image forming units 1Y, 1M, 1C, and 1K, and a primary transfer unit 118 that sequentially transfers (primary transfer) the color component toner images formed by the image forming units 1Y, 1M, 1C, and 1K to the intermediate transfer belt 115. A secondary transfer unit 120 for collectively transferring (secondarily transferring) the superimposed toner image transferred on the intermediate transfer belt 115 to a sheet K (an example of a recording medium), and fixing the secondary transferred image on the sheet K And a fixing device 50 (an example of a fixing unit). Further, the image forming apparatus 10 has a control unit 140 that exchanges information with each device (each unit) and controls the operation of each device (each unit).
Note that a unit having the intermediate transfer belt 115, the primary transfer unit 118, and the secondary transfer unit 120 corresponds to an example of a transfer unit.

  Each of the image forming units 1Y, 1M, 1C, and 1K of the image forming apparatus 10 includes a photosensitive member 111 (an example of an image holding member) that rotates in the direction of an arrow A as an example of an image holding member that holds a toner image formed on the surface. ).

  Around the photoconductor 111, a charger 112 for charging the photoconductor 111 is provided as an example of a charging unit, and a laser exposure unit that writes an electrostatic charge image on the photoconductor 111 is provided as an example of an electrostatic image forming unit. 113 (an exposure beam is indicated by reference numeral Bm in the figure).

Around the photoconductor 111, as an example of a developing unit, there is provided a developing unit 114 that accommodates each color component toner and visualizes an electrostatic charge image on the photoconductor 111 with toner. A primary transfer roll 116 for transferring the respective color component toner images formed on the intermediate transfer belt 115 at the primary transfer unit 118 is provided.
Note that a specific toner is used as at least one of the above-described color component toners. In this embodiment, all the color component toners are preferably specific toners in terms of ensuring low-temperature fixability.

  Further, a photoconductor cleaner 117 for removing residual toner on the photoconductor 111 is provided around the photoconductor 111, and includes a charger 112, a laser exposure device 113, a developing device 114, a primary transfer roll 116, and a photoconductor cleaner. Electrophotographic devices 117 are sequentially arranged along the rotation direction of the photoconductor 111. These image forming units 1Y, 1M, 1C, and 1K are arranged substantially linearly in the order of yellow (Y), magenta (M), cyan (C), and black (K) from the upstream side of the intermediate transfer belt 115. Have been.

  The intermediate transfer belt 115 is circulated (rotated) at various speeds in a direction B shown in FIG. The various rolls include a drive roll 131 driven by a motor (not shown) to rotate the intermediate transfer belt 115 and a support roll 132 that supports the intermediate transfer belt 115 extending substantially linearly along the direction in which the photoconductors 111 are arranged. , A tension applying roll 133 that functions as a correction roll that applies tension to the intermediate transfer belt 115 and suppresses the meandering of the intermediate transfer belt 115, a back roll 125 provided in the secondary transfer unit 120, and remains on the intermediate transfer belt 115. It has a cleaning back roll 134 provided in a cleaning unit for scraping toner.

The primary transfer unit 118 includes a primary transfer roll 116 as an opposing member that is disposed to face the photoconductor 111 with the intermediate transfer belt 115 interposed therebetween. The primary transfer roll 116 is composed of a core and a sponge layer as an elastic layer fixed around the core. The core is a cylindrical rod made of metal such as iron or SUS. The sponge layer is formed of a rubber blend of NBR, SBR and EPDM containing a conductive agent such as carbon black, and is a sponge-shaped cylindrical roll having a volume resistivity of ^107.5 Ωcm or more and ^108.5 Ωcm or less.

  The primary transfer roll 116 is pressed against the photoconductor 111 with the intermediate transfer belt 115 interposed therebetween, and the primary transfer roll 116 has a voltage (primary polarity) opposite to the polarity (negative polarity; the same applies hereinafter) of the toner. (Transfer bias) is applied. As a result, the toner images on the respective photoconductors 111 are sequentially electrostatically attracted to the intermediate transfer belt 115, and a superimposed toner image is formed on the intermediate transfer belt 115.

  The secondary transfer unit 120 includes a back roll 125 and a secondary transfer roll 122 disposed on the toner image holding surface side of the intermediate transfer belt 115.

The back roll 125 is made of a blend rubber tube of EPDM and NBR in which carbon is dispersed on the surface, and the inside is made of EPDM rubber. Then, the surface resistivity is formed to be 10 ⁷ Ω / □ or more and 10 ¹⁰ Ω / □ or less, and the hardness is set to, for example, 70 ° (Asker C: manufactured by Kobunshi Keiki Co., Ltd .; the same applies hereinafter). You. The back roll 125 is disposed on the back side of the intermediate transfer belt 115 and forms a counter electrode of the secondary transfer roll 122. A metal power supply roll 126 to which a secondary transfer bias is stably applied is in contact with the back roll 125. ing.

On the other hand, the secondary transfer roll 122 includes a core and a sponge layer as an elastic layer fixed around the core. The core is a cylindrical rod made of metal such as iron or SUS. The sponge layer is formed of a rubber blend of NBR, SBR and EPDM containing a conductive agent such as carbon black, and is a sponge-shaped cylindrical roll having a volume resistivity of ^107.5 Ωcm or more and ^108.5 Ωcm or less.

  The secondary transfer roll 122 is pressed against the rear roll 125 with the intermediate transfer belt 115 interposed therebetween, and the secondary transfer roll 122 is further grounded to form a secondary transfer bias between the secondary transfer roll 122 and the rear roll 125. The toner image is secondarily transferred onto a sheet (an example of a recording medium) K conveyed to the transfer unit 120.

  On the downstream side of the secondary transfer section 120 of the intermediate transfer belt 115, an intermediate transfer belt for removing residual toner and paper dust on the intermediate transfer belt 115 after the secondary transfer and cleaning the surface of the intermediate transfer belt 115 A cleaner 135 is provided so as to be able to freely contact and separate.

  The intermediate transfer belt 115, the primary transfer unit 118 (primary transfer roll 116), and the secondary transfer unit 120 (secondary transfer roll 122) correspond to an example of a transfer unit.

  On the other hand, on the upstream side of the yellow image forming unit 1Y, a reference sensor (home position sensor) 142 that generates a reference signal serving as a reference for setting an image forming timing in each of the image forming units 1Y, 1M, 1C, and 1K. It is arranged. An image density sensor 143 for adjusting image quality is provided downstream of the black image forming unit 1K. The reference sensor 142 recognizes a mark provided on the back side of the intermediate transfer belt 115 and generates a reference signal. In response to an instruction from the control unit 140 based on the recognition of the reference signal, each of the image forming units 1Y, 1Y, 1M, 1C, and 1K are configured to start image formation.

  Further, in the image forming apparatus according to the present embodiment, as a transport unit that transports the paper K, the paper storage unit 150 that stores the paper K, and the paper K accumulated in the paper storage unit 150 is taken out at a predetermined timing. Roll 151 for transporting the paper K fed by the paper feed roll 151, a transport guide 153 for feeding the paper K transported by the transport roll 152 to the secondary transfer unit 120, and secondary transfer The fixing device 50 includes a transport belt 155 that transports the paper K that is transported after the secondary transfer by the roll 122 to the fixing device 50 (an example of a fixing unit), and a fixing entrance guide 156 that guides the paper K to the fixing device 50.

  The control unit 140 is configured as a computer that controls the entire apparatus and performs various calculations. Specifically, for example, the control unit 140 includes a CPU (Central Processing Unit), a ROM (Read Only Memory) storing various programs, and a RAM (Random Access Memory) used as a work area when executing the programs. ), A nonvolatile memory for storing various information, and an input / output interface (I / O) (all not shown). Each of the CPU, ROM, RAM, nonvolatile memory, and I / O is connected via a bus.

  The image forming apparatus 10 includes an operation display unit, an image processing unit, an image memory, a storage unit, a communication unit, and the like in addition to the control unit 140 (all are not shown). The operation display unit, the image processing unit, the image memory, the storage unit, and the communication unit are connected to the I / O of the control unit 140. The control unit 140 exchanges information with the operation display unit, the image processing unit, the image memory, the storage unit, and the communication unit to control each unit. The fixing set temperature is also controlled by the control unit 140.

Next, a basic image forming process of the image forming apparatus according to the present embodiment will be described.
In the image forming apparatus according to the present embodiment, image data output from an image reading device (not shown), a personal computer (PC) not shown, or the like is subjected to image processing by an image processing device (not shown), and then the image forming unit 1Y , 1M, 1C, and 1K perform an image forming operation.

  The image processing apparatus performs image processing such as shading correction, position shift correction, brightness / color space conversion, gamma correction, various image editing such as frame erasing, color editing, and moving editing on the input reflectance data. Is done. The image data subjected to the image processing is converted into four color material gradation data of Y, M, C, and K, and output to the laser exposure device 113.

  The laser exposure device 113 irradiates, for example, an exposure beam Bm emitted from a semiconductor laser to each of the photoconductors 111 of the image forming units 1Y, 1M, 1C, and 1K according to the input color material gradation data. . In each of the photoconductors 111 of the image forming units 1Y, 1M, 1C, and 1K, after the surface is charged by the charger 112, the surface is scanned and exposed by the laser exposure device 113 to form an electrostatic image. The formed electrostatic image is developed by each of the image forming units 1Y, 1M, 1C, and 1K as a toner image of each color of Y, M, C, and K.

  The toner images formed on the photoconductors 111 of the image forming units 1Y, 1M, 1C, and 1K are transferred onto the intermediate transfer belt 115 at a primary transfer unit 118 where the respective photoconductors 111 and the intermediate transfer belt 115 are in contact. You. More specifically, in the primary transfer section 118, a voltage (primary transfer bias) having a polarity opposite to the charging polarity (minus polarity) of the toner is applied to the base material of the intermediate transfer belt 115 by the primary transfer roll 116, and the toner image is formed. Are sequentially superimposed on the surface of the intermediate transfer belt 115 to perform primary transfer.

  After the toner image is sequentially primary-transferred onto the surface of the intermediate transfer belt 115, the intermediate transfer belt 115 moves and the toner image is transported to the secondary transfer unit 120. When the toner image is transported to the secondary transfer unit 120, the transport unit rotates the paper feed roll 151 in synchronization with the timing at which the toner image is transported to the secondary transfer unit 120, and moves the paper roll 151 from the paper storage unit 150 to the target. Paper K of a size is supplied. The paper K supplied by the paper feed roll 151 is transported by the transport roll 152 and reaches the secondary transfer unit 120 via the transport guide 153. Before reaching the secondary transfer unit 120, the sheet K is temporarily stopped, and the alignment roller (not shown) is rotated in accordance with the movement timing of the intermediate transfer belt 115 holding the toner image, so that the sheet K is rotated. And the position of the toner image are aligned.

  In the secondary transfer unit 120, the secondary transfer roll 122 is pressed against the back roll 125 via the intermediate transfer belt 115. At this time, the sheet K conveyed in a timely manner is sandwiched between the intermediate transfer belt 115 and the secondary transfer roll 122. At this time, when a voltage (secondary transfer bias) having the same polarity as the charging polarity (minus polarity) of the toner is applied from the power supply roll 126, a transfer electric field is formed between the secondary transfer roll 122 and the back roll 125. Is done. Then, the unfixed toner image held on the intermediate transfer belt 115 is collectively electrostatically transferred onto the sheet K in the secondary transfer unit 120 pressed by the secondary transfer roll 122 and the back roll 125. You.

  Thereafter, the sheet K on which the toner image has been electrostatically transferred is conveyed as it is separated from the intermediate transfer belt 115 by the secondary transfer roll 122, and is provided on the downstream side of the secondary transfer roll 122 in the sheet conveying direction. It is transported to the belt 155. The transport belt 155 transports the sheet K to the fixing device 50 in accordance with the optimal transport speed of the fixing device 50. The unfixed toner image on the sheet K conveyed to the fixing device 50 undergoes a fixing process by heat and pressure by the fixing device 50 and is fixed on the sheet K. Then, the sheet K on which the fixed image is formed is conveyed to a sheet discharge storage unit (not shown) provided in a discharge unit of the image forming apparatus.

  On the other hand, after the transfer to the paper K is completed, the residual toner remaining on the intermediate transfer belt 115 is conveyed to the cleaning unit with the rotation of the intermediate transfer belt 115, and is cleaned by the cleaning back roll 134 and the intermediate transfer belt cleaner 135. The toner is removed from the intermediate transfer belt 115.

[Fixing means]
The fixing unit according to the exemplary embodiment includes a belt member that makes the outer peripheral surface contact the first surface (toner image surface) of the recording medium, and a rotating body that contacts the outer peripheral surface of the belt member to form a contact area (nip). A fixing member that includes a pair of rotating members and heats the recording medium onto which the toner image has been transferred by inserting the recording medium into the contact area (nip) and fixing the toner image on the first surface.

In the present embodiment, it is preferable that the member that plays the role of heating the toner image in the rotating body pair is a belt member. That is, it is preferable that the belt member that brings the outer peripheral surface into contact with the first surface of the recording medium is a heating belt member that heats the toner image.
Since the belt member plays a role of heating, the air supply pipe surrounded by the belt member is easily heated, and the adhesion of the coagulated UFP to the inside of the air supply pipe is easily suppressed.

When the belt member is a heating belt member that plays a role of heating the toner image, it is preferable that a heating member that contacts and heats the belt member is further provided on the inner peripheral surface side of the belt member.
By providing a heating member for heating the belt member on the inner peripheral surface side of the belt member, the air supply pipe is also warmed by heat from the heating member, and it is easy to suppress the adhesion of the coagulated UFP to the inside of the air supply pipe. .

Furthermore, when a heating member is provided on the inner peripheral surface side of the belt member to heat the belt member by contacting the belt member, it is preferable that the air supply pipe is disposed above the heating member in the direction of gravity.
By arranging the air supply pipe above the heating member in the direction of gravity, the air supply pipe is easily heated by heat from the heating member, and adhesion of the coagulated UFP to the inside of the air supply pipe is easily suppressed.

The set fixing temperature of the rotating body pair is preferably from 100 ° C to 200 ° C, more preferably from 120 ° C to 200 ° C, and even more preferably from 130 ° C to 200 ° C.
When the fixing temperature of the rotating body pair is equal to or higher than 100 ° C., it is easy to secure the fixing property of the image. On the other hand, when the fixing temperature of the rotating body pair is 200 ° C. or lower, energy saving by low-temperature fixing can be easily achieved. Further, the amount of UFP generated on the upstream side of the nip can be easily suppressed, and the adhesion of the coagulated product of UFP to the inside of the air supply pipe can be easily suppressed.

Here, the fixing set temperature in the rotating body pair will be described.
The heating of the rotating body pair is normally performed by the rotating body on the side in contact with the toner image. For example, the belt member that contacts the first surface (toner image surface) side of the recording medium is a heating belt member that has a heating mechanism on at least one of the inside and the outside thereof, and is a member opposite to the first surface of the recording medium. There is an embodiment in which the rotating body that contacts the surface (hereinafter, also simply referred to as “back side”) is a pressurizing rotating body that pressurizes without heating. However, both the rotating member, that is, the belt member that contacts the first surface (toner image surface) side and the rotating member that contacts the back surface side, may play a role of heating.
The set fixing temperature of the pair of rotating members refers to a target value of the temperature of the portion of the rotating member (that is, the belt member) that contacts the toner image on the surface of the rotating member (that is, the belt member) that contacts the toner image. That is, it indicates the target value of the surface temperature of the belt member at the moment when the belt member contacts the toner image and the heat has not yet moved to the toner image.

In the present embodiment, it is preferable that the rotating body that contacts the outer peripheral surface of the belt member in the rotating body pair to form a contact area is a roll member. For example, a rotating member pair (that is, a belt member) includes a belt member that heats the toner image by contacting the first surface (toner image surface) of the recording medium and a roll member that contacts the opposite surface (back surface) of the recording medium. Roll body).
In the above-described belt-roll rotating body pair, the width (so-called nip width) of the contact area (nip) in the recording medium transport direction can be increased, and high pressure can be applied by the roll member. When the rotating body pair is in this mode, the fixing set temperature can be reduced while securing the total amount of heat and pressure for fixing, and as a result, it is easy to achieve energy saving by low-temperature fixing while securing the fixing strength of the image. . And it becomes easy to suppress the amount of UFP generated on the upstream side of the nip, and it becomes easy to suppress the adhesion of the coagulated product of UFP to the inside of the air supply pipe.

  However, the rotating body pair in the present embodiment is not limited to this mode. For example, a rotating member pair (that is, a two-belt rotating member pair) of a belt member that contacts a first surface (toner image surface) of a recording medium and a second belt member that contacts an opposite surface (rear surface) of the recording medium. It may be.

In the present embodiment, a belt rotating body having a metal layer as a belt member can also be used. For example, an induction heating (IH) heating method can be adopted as a heating method.
In addition, as a belt member for the IH heating method, a belt member provided with a metal layer and a protective layer on a base material is exemplified. In addition, the belt member for the IH heating system may further include at least one of an elastic layer and a surface layer (release layer) on the protective layer.

Here, the fixing unit in the present embodiment will be described by way of an example with reference to the drawings.
The fixing device 50 illustrated in FIGS. 1 and 2 is an example of a fixing unit.

FIG. 2 is a schematic configuration diagram showing the fixing device 50 and the duct 100 in the image forming apparatus 10 in an enlarged manner.
The fixing device 50 is configured to rotate and drive the paper K (an example of a recording medium) to contact and press the surface (second surface, back surface) of the paper K (an example of a recording medium) having no toner image. And a heating belt 62 for applying pressure and heat in contact with the surface (first surface, toner image surface) having the K toner image. The pressure roll 61 and the heating belt 62 are an example of a rotating body pair, and a nip (contact area) N is formed by a region where the pressure roll 61 and the heating belt 62 are in contact.

(Rotating body pair)
Heating belt As the heating belt 62, for example, a belt using a resin material or a metal material may be used. The heating belt 62 may be a belt having a single layer configuration or a belt having a multilayer configuration in which a plurality of layers are stacked.

As a belt having a single-layer structure, a belt using a resin material is exemplified. Examples of the resin material include a resin generally called an engineering plastic.
Examples of engineering plastics include fluororesin, polyimide (PI, thermosetting polyimide, thermoplastic polyimide), fluorinated polyimide, polyamideimide (PAI), polybenzimidazole (PBI), polyetheretherketone (PEEK), and polysulfone. (PSU), polyether sulfone (PES), polyphenylene sulfide (PPS), polyetherimide (PEI), wholly aromatic polyester (liquid crystal polymer) and the like.
Among these, the imide resin layer (in the molecular structure) is used from the viewpoint of enhancing the heat retaining property of the belt member and easily heating the air supply pipe, thereby easily suppressing the adhesion of the coagulated UFP to the inside of the air supply pipe. A layer mainly composed of a resin having an imide bond) is preferable, and for example, a resin layer of polyimide, fluorinated polyimide, polyamideimide, or polyetherimide is preferable. Further, a polyimide resin layer is more preferable. Note that the imide-based resin layer is also preferable in terms of mechanical strength, heat resistance, wear resistance, and the like.

  In addition, as a belt having a single-layer structure, a belt using a metal material is exemplified. Examples of the metal material include various metals such as SUS, nickel, copper, and aluminum.

  Examples of the belt having a laminated configuration include a belt in which another layer (for example, an elastic layer and a surface layer) is laminated on a base material.

Examples of the base material include those using a resin material or a metal material. Examples of these materials include the resin materials and the metal materials listed in the above-described single-layer belt. Note that a base material may be formed by stacking a resin material layer and a metal material layer.
Among these, the imide-based resin layer is used as the base material from the viewpoint that the heat retention of the belt member is enhanced and the air supply pipe is easily heated, so that the adhesion of the coagulated UFP to the inside of the air supply pipe is easily suppressed. Preferably, for example, a resin layer of polyimide, fluorinated polyimide, polyamideimide, or polyetherimide is preferable, and a polyimide resin layer is more preferable.

The elastic layer is a layer provided from the viewpoint of imparting elasticity to pressure applied to the heating belt 62 from the outer peripheral side.
Examples of the material of the elastic layer include a fluorine resin, a silicone resin, a silicone rubber, a fluorine rubber, a fluorosilicone rubber, and the like. From the viewpoint of heat resistance, thermal conductivity, insulation, and the like, for example, silicone rubber is preferable.

For example, heat resistance and mold release properties are required for the surface layer. From this viewpoint, it is preferable to use a heat-resistant release material as a material constituting the surface layer, and specific examples thereof include fluororubber, fluororesin, silicone resin, and polyimide resin.
Among these, a fluorine resin is preferable as the heat-resistant release material.
Specific examples of such a fluororesin include tetrafluoroethylene-perfluoroalkylvinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and polyethylene. -Tetrafluoroethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), polychloroethylene trifluoride (PCTFE), vinyl fluoride (PVF) and the like.

  Note that an adhesive layer may be provided between at least one of the substrate and the elastic layer and between the elastic layer and the surface layer.

  Inside the heating belt 62, a heating element 64 is provided as a heating member that presses the pressure roll 61 via the heating belt 62 and heats the heating belt 62. When the heating belt 62 is pressed by the heating element 64, a nip N through which the paper K passes is formed between the heating belt 62 and the pressure roll 61. Further, a belt running guide 63 and a belt running assist guide 66 are provided inside the heating belt 62, and the heating belt 62 extends along the outer peripheral surfaces of the belt running guide 63, the belt running assist guide 66, and the heating element 64. It is configured to move around. A sliding member 69 is provided between the belt traveling guide 63 and the heating belt 62.

Heating Element On the inner peripheral surface of the heating belt 62 at a position facing the pressure roll 61, a heating element 64 is provided as a heating member for applying heat to the heating belt 62 so as to be in contact therewith. The heating element 64 is disposed so as to face the pressure roll 61 via the heating belt 62, and presses the heating belt 62 from the inner peripheral surface of the heating belt 62 to the pressure roll 61, thereby forming the heating belt 62 and the pressure roll. 61, a nip N through which the paper K passes is formed.

  It is sufficient that the heating belt 62 and the pressure roll 61 are relatively pressurized. Therefore, the heating belt 62 may be pressed toward the pressure roll 61 by the heating element 64. The pressure roll 61 may be pressed toward the heating belt 62 side.

The heating element 64 has a heating source inside. As the heating source, for example, a configuration is adopted in which a resistance heating element that generates Joule heat by supplying power is sandwiched between a pair of support plates, and heat generated from the resistance heating element is applied to the heating belt 62 via the support plate. An example of the transmitted mode is given. The material of the support plate is preferably a metal such as aluminum or stainless steel from the viewpoint of heat conductivity.
Note that the heating source is not limited to the heating element, and a known heating source such as a halogen lamp may be used.

Belt running guide and belt running assist guide The belt running guide 63 and the belt running assist guide 66 are provided in an arc shape inside the heating belt 62 so as to conform to the shape of the heating belt 62 so that the heating belt 62 can move around. To support.
Examples of the material of the belt traveling guide 63 and the belt traveling auxiliary guide 66 include heat-resistant resins such as polyphenylene sulfide (PPS), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and liquid crystal polymer (LCP). In addition, a material obtained by adding a filler for lowering durability or a coefficient of friction to the heat-resistant resin may be used.
A sliding member 69 is provided between the belt traveling guide 63 and the heating belt 62 from the viewpoint of further reducing durability and friction coefficient.

Pressure Roll The pressure roll 61 is disposed, for example, around a solid metal core (cylindrical core) 61A, an elastic layer 61B disposed around the core 61A, and a periphery of the elastic layer 61B. It is a cylindrical roll provided with a surface layer 61C. The pressure roll 61 is not limited in its shape, structure, size and the like, and a known pressure roll is used depending on the purpose.

  Both ends of the core 61A are rotatably supported by, for example, bearing members (not shown), and are predetermined with respect to the heating belt 62 by urging members such as coil springs disposed at both ends of the core 61A. It is pressed by pressure.

  Examples of the material of the core 61A of the pressure roll 61 include metals or alloys having high thermal conductivity such as iron, aluminum (for example, A-5052), SUS, copper, etc., ceramics, and fiber reinforced metal (FRM). Can be

  Examples of the material of the elastic layer 61B of the pressure roll 61 include rubber, elastomer, foamed resin and the like having a hardness (JIS-A: hardness measured by a JIS-KA type testing machine) of 15 ° or more and 60 ° or less. More specifically, examples thereof include silicone rubber, fluorine rubber, and liquid silicone rubber filled with hollow glass beads.

  The material of the surface layer 61C of the pressure roll 61 is, for example, resin. Examples of the resin forming the surface layer 61C include tetrafluoroethylene-perfluoroalkylvinylether copolymer (PFA), polytetrafluoroethylene (PTFE), and tetrafluoroethylene Fluororesins such as hexafluoropropylene copolymer (FEP), silicone resins, silicone rubbers, fluororubbers, fluorinated polyimides and the like are included.

  Note that an adhesive layer may be provided between at least one of the core 61A and the elastic layer 61B and between the elastic layer 61B and the surface layer 61C.

  In the above-described configuration, the pressure roll 61 is rotated by, for example, a drive motor (not shown), and the heating belt 62 rotates in a direction opposite to the rotation direction of the pressure roll 61 following this rotation. That is, for example, while the pressure roll 61 rotates clockwise in FIG. 2, the heating belt 62 rotates counterclockwise.

  Next, the operation of the fixing device 50 will be described.

In the fixing device 50, first, a sheet K having a toner image is inserted into a nip N by a pressure roll 61 and a heating belt 62, which are examples of a rotating body pair. Specifically, the pressure roll 61 is rotated by a drive motor (not shown), and the heating belt 62 rotates in a direction opposite to the rotation direction of the pressure roll 61 following this rotation. Then, the paper K on which the unfixed toner image is formed is guided by the fixing entrance guide 156 (see FIG. 1), and is conveyed to the nip N formed by the heating belt 62 and the pressure roll 61. . When the sheet K passes through the nip N, pressure and heat acting on the nip N are applied to the toner image on the sheet K, and then the sheet K is discharged from the nip N.
Thus, the toner image is fixed on the surface of the sheet K by the pressure roll 61 and the heating belt 62.

[Air pipe]
The image forming apparatus according to this embodiment includes an air supply inlet provided around the nip on the upstream side of the contact area (nip) in the fixing unit in the recording medium transport direction and on the first surface (toner image surface) side of the recording medium. And an air supply outlet provided around the conveyance path of the recording medium on the downstream side of the contact area (nip) in the recording medium conveyance direction and on the first surface (toner image surface) side of the recording medium. An air supply pipe for exhausting gas entering from the air supply outlet toward the recording medium.
Further, the air supply pipe is arranged to connect the air supply inlet and the air supply outlet through the inner peripheral side of the belt member in the rotating body pair.

Thus, by providing the air supply pipe connecting the air supply inlet and the air supply outlet, particles (UFP) having a particle diameter of 100 nm or less derived from the vaporized release agent and generated at the upstream side of the nip are supplied to the air supply pipe. It is conveyed to the outlet and exhausted from the air supply outlet toward the recording medium. Then, the particles (UFP) are conveyed to the outside of the apparatus together with the recording medium in a state in which the particles (UFP) adhere to and are fixed on the recording medium, so that the particles (UFP) are prevented from drifting in the air and being directly discharged to the outside of the apparatus. Is done. That is, the amount of particles (UFP) having a particle size of 100 nm or less discharged outside the apparatus is reduced.
In addition, the configuration in which the air supply pipe passes through the inner peripheral side of the belt member means that the air supply pipe is partially surrounded by the belt member. Therefore, in a portion surrounded by the belt member, the air supply pipe is warmed by radiant heat from the belt member. As a result, the air inside the air supply pipe is also warmed, and the UFP passing through the air supply pipe is cooled and solidified, and is prevented from adhering to the inside of the air supply pipe. As a result, adhesion of the coagulated UFP to the inside of the air supply pipe is suppressed.

Here, the air supply pipe in the present embodiment will be described with reference to the drawings.
The duct 100 shown in FIGS. 2 to 5 is an example of an air pipe.

FIG. 2 is a schematic configuration diagram illustrating the fixing device and the duct as viewed from the axial direction of the pressure roll and the heating belt.
FIG. 3 is a schematic perspective view showing the fixing device and the duct on the upstream side in the transport direction of the sheet (recording medium).
FIG. 4 is a schematic perspective view showing the fixing device and the duct on the downstream side in the transport direction of the sheet (recording medium), as viewed from the back side of FIG. 3.
FIG. 5 is a schematic configuration diagram showing the heating belt and the duct viewed from the first surface (toner image surface) side of the paper (recording medium).

As shown in FIG. 2, the duct 100 is located upstream of a nip (contact area) N formed by a pressure roll 61 and a heating belt 62 corresponding to a pair of rotating members, On the (image plane) side, it has an air supply inlet 102A provided around the nip N. As shown in FIGS. 3 and 5, the air supply inlet 102 </ b> A has a width longer in the width direction (in the same direction as the axial direction of the pressure roll 61 and the heating belt 62) than the width of the paper K in the width direction. Shape.
Further, the duct 100 has an air supply outlet 106A provided around the transport path of the paper K on the first surface (toner image surface) side of the paper K on the downstream side of the nip (contact area) N. . As shown in FIGS. 4 and 5, the air supply outlet 106A has a shape having a width shorter than the width of the sheet K in the width direction.
The air supply inlet 102A and the air supply outlet 106A are connected by an inlet side air supply unit 102B, a belt air supply unit 104, and an outlet side air supply unit 106B.

As shown in FIG. 2, the shape of the air supply inlet 102A is such that when viewed from the width direction (same as the axial direction of the heating belt 62 or the like), the nip is formed from a connection portion with the inlet side air supply portion 102B. It has a shape bent in the N direction. Further, the surface forming the inlet of the air supply inlet 102A is inclined with respect to the sheet K transport path when viewed from the width direction, and the air supply inlet 102A faces the direction of the nip N. That is, the end of the air supply inlet 102A on the side closer to the heating belt 62 is farther from the conveyance path of the sheet K, and the end of the air supply inlet 102A on the side farther from the heating belt 62 is closer to the conveyance path of the sheet K. Are located. With this arrangement, the air supply inlet 102A is arranged so as to face the nip N direction.
Since the air supply inlet 102A has a shape facing the direction of the nip N, the release agent-derived UFP generated on the upstream side of the nip N is easily taken in from the air supply inlet 102A.

  Further, as shown in FIG. 2, the shape of the air supply inlet 102A is such that when viewed from the width direction, the skirt side (the inlet side) expands from the inlet side air supply portion 102B toward the nip N. . Since the air supply inlet 102A has a shape that expands toward the nip N, the release agent-derived UFP generated on the upstream side of the nip N is easily taken in from the air supply inlet 102A.

As shown in FIGS. 3 and 5, the shape of the air supply inlet 102A is such that, as viewed from the paper K transport direction, the closer to the paper K transport path from the connection with the inlet-side air supply unit 102B, the wider the width direction. It has a shape that spreads out. The length of the surface forming the inlet in the air supply inlet 102A is set to be longer in the width direction than the width of the sheet K in the width direction.
Since the air inlet 102A has a shape that widens in the width direction as it approaches the paper K transport path, the release agent-derived UFP generated on the upstream side of the nip N is easily taken in from the air inlet 102A.

  The length in the width direction of the air supply inlet 102A (the width direction length of the longest portion in the air flow path portion) is the width direction length of the sheet K (the width of the sheet having the maximum width that can be inserted into the image forming apparatus). (Length in the direction of the paper K), and more specifically, preferably has a width that is longer than the length of the sheet K in the width direction by not less than 10 mm and not more than 30 mm, respectively.

  The vicinity of the nip N where the air supply inlet 102A is provided is defined as a vapor generated from the toner image, the paper K and the like in the nip N and floating on the upstream side, and the vapor is solidified again. It indicates a range from the air supply inlet 102A to a distance at which generated particles and the like can be taken.

Here, the distance from each part of the air supply inlet 102A will be described with reference to FIG.
From the viewpoint that the release agent-derived UFP generated on the upstream side of the nip N is easily taken in from the air supply inlet 102A, the distance from each part of the air supply inlet 102A is preferably within the following range.
When viewed from the width direction, the end of the air supply inlet 102A on the side close to the heating belt 62 is set at a distance of 10 mm or more and 40 mm or less (more preferably 10 mm or more and 30 mm or less) from the upstream end of the nip N. Preferably.
When viewed from the width direction, the end of the air supply inlet 102A on the side close to the heating belt 62 is set at a distance of 10 mm or more and 50 mm or less (more preferably 10 mm or more and 30 mm or less) from the surface of the heating belt 62. Is preferred.
When viewed from the width direction, the end of the air supply inlet 102A on the side close to the heating belt 62 may be installed at a distance of 10 mm or more and 40 mm or less (more preferably 10 mm or more and 30 mm or less) from the paper K transport path. preferable.

The end of the air supply inlet 102A farther from the heating belt 62 when viewed from the width direction is installed at a distance of 10 mm or more and 50 mm or less (more preferably 10 mm or more and 30 mm or less) from the upstream end of the nip N. Preferably.
When viewed from the width direction, the end of the air supply inlet 102A farther from the heating belt 62 may be installed at a distance of 10 mm or more and 40 mm or less (more preferably 10 mm or more and 30 mm or less) from the paper K transport path. preferable.

As shown in FIG. 2, the shape of the air supply outlet 106A is different from the shape of the air supply outlet 106B when viewed from the width direction (the same as the axial direction of the heating belt 62 and the pressure roll 61). The skirt side (exit side) widens from the connection portion toward the paper K transport path. Since the air supply outlet 106A has a shape expanding toward the paper K transport path, the uniformity of the attachment of the UFP onto the paper K is easily increased.
Further, as shown in FIG. 2, the air supply outlet 106A is disposed so as to face the sheet K passing through the transport path so that a surface forming the outlet is parallel to the sheet K transport path. Since the air supply outlet 106A is arranged to be parallel to the transport path and to face the sheet K, the UFP sent by the duct 100 can be easily attached to the sheet K.

As shown in FIGS. 4 and 5, the shape of the air supply outlet 106A is such that, as viewed from the paper K conveyance direction, the closer to the conveyance path of the paper K from the connection portion with the outlet side air supply unit 106B, the width direction. It has a shape that spreads out. The length of the surface forming the outlet in the air supply outlet 106A is set shorter than the length of the sheet K in the width direction.
Since the air supply outlet 106A has a shape that expands in the width direction as it approaches the transport path of the sheet K, the uniformity of the attachment of the UFP onto the sheet K is easily increased.

  The length in the width direction of the air supply outlet 106A (the length in the width direction of the longest part in the air flow path portion) is the length in the width direction of the paper K (the width of the maximum width of the paper that can be inserted into the image forming apparatus). (Specifically, the length in the direction of the paper K), and more specifically, the width of the sheet K is preferably 10 mm or more and 40 mm or less on both ends.

  The vicinity of the paper K transport path where the air supply outlet 106A is provided means that the UFP contained in the air exhausted from the air supply outlet 106A toward the paper K is the surface of the toner image on the paper K and the paper. It refers to the range up to a distance that can be attached to a region having no toner image on the K surface.

Here, the distance from each part of the air supply outlet 106A will be described with reference to FIG.
The air supply outlet 106A is preferably installed at a distance of 10 mm or more and 40 mm or less (more preferably 10 mm or more and 30 mm or less) from the paper K transport path from the viewpoint of making the UFP easily adhere to the paper K.

It is preferable that the air supply outlet 106A be provided at a position where the sheet K can be exhausted after the sheet K is inserted into the nip N and before the heated toner image is completely solidified. By exhausting the toner image before solidification, that is, the toner image that is still in a molten state, from the air supply outlet 106A, it becomes easier for the UFP to adhere to the toner image on the paper K.
From this viewpoint, the distance in the paper K transport direction between the end of the air supply outlet 106A on the side close to the heating belt 62 and the downstream end of the nip N (that is, the distance between the downstream end of the nip N and the paper K transport path) The distance from the position corresponding to the end of the air outlet 106A) is preferably 10 mm or more and 40 mm or less (more preferably 10 mm or more and 30 mm or less).

  The end of the air supply outlet 106A on the side close to the heating belt 62 is preferably set at a distance of 10 mm or more and 40 mm or less (more preferably 10 mm or more and 30 mm or less) from the surface of the heating belt 62.

-Air supply part Duct 100 is arrange | positioned so that a part may pass through the inner peripheral surface side of the heating belt 62. FIG. As shown in FIGS. 3, 4, and 5, the in-belt air supply unit 104, which is a region passing through the inner peripheral surface of the heating belt 62 of the duct 100, passes straight through the inner peripheral surface of the heating belt 62. Are located.

The in-belt air supply section 104 passes through the center of the heating belt 62. That is, when viewed from the width direction, the distance from the heating belt 62 on the lower side (that is, the transport path side of the paper K) is equal to the distance from the heating belt 62 on the upper side (that is, the opposite side to the transport path of the paper K). The heating belt 62 on the upstream side and the heating belt 62 on the downstream side are positioned at the same distance from each other.
However, the arrangement position of the in-belt air supply unit 104 is not limited to the position passing through the center of the heating belt 62, and may be, for example, a heating element 64 provided to be in contact with the inner peripheral surface side of the heating belt 62. The arrangement position may be adjusted in relation to the above.

  For example, the distance (the shortest distance) between the surface of the belt air supply unit 104 and the surface of the heating element 64 is 10 mm or more and 50 mm or less (more preferably 10 mm or more and 30 mm or less) from the viewpoint of making it easier to warm the belt air supply unit 104. ) Is preferable.

Further, the maximum diameter of the air supply section 104 in the belt (in the case of a cylindrical shape, the outer shape of the portion having the largest diameter, and in the case of a shape other than a cylinder such as a prism, in the longitudinal direction of the air supply section 104 in the belt). The length between the outer surfaces of the longest part in the direction perpendicular to the belt means the distance between the outer surfaces of the belt 104 and the arrangement of other members on the inner peripheral surface side of the heating belt 62. From the viewpoint that this does not occur, it is preferably 2 mm or more and 10 mm or less, and more preferably 2 mm or more and 7 mm or less.
Note that the maximum diameter _{D 1} of the belt in the air unit 104, a ratio to the inner diameter _{B 1} of the heating belt _{62 (D 1 / B 1 ×} 100 [%]) is the viewpoint of easily warmed belt inside air section 104, From the viewpoint that it does not hinder the arrangement of other members on the inner peripheral surface side of the heating belt 62, it is preferably 1% or more and 20% or less, and more preferably 1% or more and 10% or less.

  The air supply inlet 102A of the duct 100 and the belt air supply unit 104 are connected by an inlet air supply unit 102B. As shown in FIG. 2, FIG. 3, and FIG. 5, the inlet side air supply unit 102B is connected to the air supply inlet 102 at the base thereof, and is temporarily opposite to the sheet K conveyance path (the upper side in FIG. 2 and FIG. 3). ), And has a path that bends at a right angle to the axial end of the heating belt 62. Then, at a position beyond the axial end of the heating belt 62, the heating belt 62 is further bent at a right angle toward the downstream side in the sheet K transport direction, and further at a position reaching the center of the heating belt 62, is bent again at a right angle to the inner peripheral side of the heating belt 62. With a path to In other words, the inlet-side air supply unit 102B extends from the connection with the air supply inlet 102 toward the axial end of the heating belt 62, bypassing the axial end of the heating belt 62, and It has a path toward the side.

  An outlet-side air supply unit 106B is connected between the air supply outlet 106A and the belt air supply unit 104 in the duct 100. As shown in FIGS. 2, 4, and 5, the outlet-side air supply unit 106 </ b> B temporarily moves from a connection with the belt air supply unit 104 in a direction away from the end in the axial direction of the heating belt 62. , Bent at a right angle toward the downstream side of the paper K transport direction, and again at a position downstream of the heating belt 62 in the paper K transport direction, again bent at a right angle, so that the outer peripheral side of the heating belt 62 is moved toward the center in the axial direction. Have a path to go. Then, the heating belt 62 is further bent at a right angle at the central position in the axial direction toward the sheet K transport path, and is connected to the air supply outlet 106A at the root thereof. In other words, the outlet-side air supply unit 106B extends from the connection with the in-belt air supply unit 104 to the downstream side in the sheet K transport direction, bypasses the axial end of the heating belt 62, and It has a path that goes to the center in the axial direction and connects to the air supply outlet 106A.

The shapes of the inlet-side air supply unit 102B, the belt-side air supply unit 104, and the outlet-side air supply unit 106B are circular tubes (tubes with a perfectly circular cross section). However, the shape is not limited to these, and is, for example, a circular tube (a tube having an elliptical cross section, etc.), a square tube (a tube having a square cross section, a tube having a rectangular cross section, a cross section other than square (for example, a triangle, a pentagon, etc.) Etc.) may be used.
It is preferable that the portions other than the bent portion (bent portion) in the inlet-side air supply portion 102B, the belt-side air supply portion 104, and the outlet-side air supply portion 106B have the same shape and the same cross-sectional area. By having the same shape and the same cross-sectional area, the air supply amount in the duct 100 can be made nearly uniform.

  The material of the duct 100 is not particularly limited, and a conventionally known material having heat resistance is used. Examples thereof include metal materials and the like, and specific examples include a steel sheet, a plated steel sheet (for example, a galvanized steel sheet, an alloy-plated steel sheet), a stainless steel sheet, and a vinyl chloride-coated steel sheet.

-Fan As shown in FIG. 5, the duct 100 has fans 108A and 108B inside the inlet side air supply unit 102B and the outlet side air supply unit 106B. By providing the fans 108A and 108B, an airflow is forcibly generated in the duct 100, so that air is generated at the air supply inlet 102A and the exhaust force at the air supply outlet 106A is increased. This makes it easier to take in the air around the nip N and the UFP on the upstream side of the nip N and on the first surface (toner image surface) side of the paper K from the air supply inlet 102A. Further, the air is exhausted from the air supply outlet 106A toward the sheet K with stronger wind force, so that the UFP easily adheres to the sheet K.

Note that the number of fans provided in the duct 100 is not particularly limited. In FIG. 5, the fans 108A and 108B are provided at two locations in the air supply direction, but the number of fans 108A and 108B in the air supply direction may be one or three or more.
However, the installation position of the fan is preferably an area other than the area passing through the inner peripheral side of the heating belt 62 of the duct 100 (that is, the air supply section 104 in the belt) from the viewpoint of suppressing the influence of heat. The inside of at least one of the inlet side air supply unit 102B and the outlet side air supply unit 106B is preferable.

  In the present embodiment, a device for forcibly generating an airflow such as a fan may not be provided inside the duct 100. In this case, the air around the upstream side of the nip N is supplied to the air inlet 102A in accordance with the flow of the airflow generated by the conveyance of the sheet K, the rotation of the heating belt 62 and the pressure roll 61, and the like on the upstream side of the nip N. Can be configured to enter the natural environment. Note that this configuration can be achieved by adjusting the shape and arrangement position of the air supply inlet 102A.

  Here, the operation of the duct 100 will be described.

  In the duct 100, the fans 108A and 108B are rotated by a drive motor (not shown) to generate an air flow in the duct 100. Then, when the sheet K having the unfixed toner image formed on the surface passes through the nip N, the vaporized material generated from the toner image, the recording medium, and the like, and floating on the upstream side, and the vaporized material Particles and the like generated by solidification again are taken in together with the air around the upstream side of the nip N from the air supply inlet 102A as shown by the dotted arrow. Then, the air taken in from the air supply inlet 102A is supplied to the inlet side air supply unit 102B, the belt air supply unit 104, and the outlet by the airflow generated in the duct 100 by the fans 108A and 108B as indicated by the dotted arrows. The air is supplied in the order of the side air supply section 106B and reaches the air supply outlet 106A. Thereafter, as indicated by the dotted arrow, the air is discharged from the air supply outlet 106A and reaches the paper K transport path. Therefore, the UFP contained in the air discharged from the air supply outlet 106A adheres to a toner image on the sheet K, an area having no toner image on the surface of the sheet K, and the like. After that, the paper K to which the UFP has adhered is conveyed on the conveyance path and discharged out of the apparatus.

  The flow velocity (air supply speed) of the air moving in the duct 100 is not particularly limited, but is preferably set in accordance with the transport speed of the paper K. More specifically, the time required for the air entering from the air supply inlet 102A to be discharged from the air supply outlet 106A to reach the paper K transport path, and for the paper K inserted through the upstream end of the nip N to be transported. It is preferable that the time until the air discharged from the air outlet 106A reaches the position where the air reaches the air outlet 106A is set to be synchronized. By setting as described above, the UFP generated from the toner image on the sheet K at the upstream end of the nip N is replaced with the same sheet K (that is, the toner image including the release agent that is the source of the UFP). On a sheet of paper K).

  As described above, the embodiments of the fixing device and the air supply pipe according to the present embodiment have been described with reference to FIGS. 2 to 5. It goes without saying that the configuration and the like can be freely changed.

(Developer)
Next, in the image forming apparatus according to the present embodiment, the toner of the developer contained in the developing unit will be described in detail.

  Hereinafter, details of the toner according to the exemplary embodiment will be described.

  The toner according to the exemplary embodiment includes toner particles and, as necessary, an external additive.

(Toner particles)
The toner particles include, for example, a binder resin, a release agent, and, if necessary, a colorant and other additives.

-Release agent-
The melting temperature of the release agent is from 60 ° C to 100 ° C, preferably from 60 ° C to 90 ° C, more preferably from 60 ° C to 75 ° C.
When the melting temperature of the release agent is 100 ° C. or lower, the low-temperature fixing property of the toner is improved, and thus the fixing temperature in the image forming apparatus can be reduced. However, if the melting temperature of the release agent is 100 ° C. or lower, the release agent is likely to be vaporized during fixing of the toner, and the vaporized release agent is likely to coagulate again in the air, thereby generating UFP. However, even in that case, according to the present embodiment, the amount of UFP generated on the upstream side of the nip is suppressed, and the adhesion of coagulated UFP to the inside of the air supply pipe is suppressed.
On the other hand, when the melting temperature of the release agent is 60 ° C. or higher, the release agent is prevented from adhering to the fixing member due to excessive melting of the release agent during fixing of the toner. Further, it is possible to suppress the occurrence of excessive UFP.
The melting temperature of the release agent is controlled by a known method such as selection of the type of the release agent.

  The melting temperature is determined from the DSC curve obtained by differential scanning calorimetry (DSC) according to the “melting peak temperature” described in JIS K 7121-1987 “Method for measuring the transition temperature of plastics”. .

The release agent is not particularly limited. For example, mineral and petroleum waxes such as montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, Fischer-Tropsch wax; polyethylene wax, polypropylene wax, and polybutene wax Hydrocarbon waxes such as silicone waxes; fatty acid amide waxes such as oleic acid amide wax, erucic acid amide wax, ricinoleic acid amide wax, stearic acid amide wax; carnauba wax, rice wax, candelilla wax, wood wax, jojoba oil Vegetable wax such as beeswax; animal wax such as beeswax; ester wax such as fatty acid ester, montanic acid ester and carboxylic acid ester; and modified products thereof. That.
Among these, paraffin wax, ceresin, carnauba wax, fatty acid ester, and montanic acid ester are preferable, and paraffin wax is more preferable, from the viewpoint of the low-temperature fixability of the toner.

  The release agent may be used alone or in combination of two or more. When two or more types are used in combination, it is preferable that the melting temperature of at least one type of the release agent is in the above-mentioned range, and further, the melting temperature of all the included release agents is in the above-mentioned range.

  The content of the release agent is, for example, preferably from 1% by mass to 20% by mass, more preferably from 5% by mass to 15% by mass, based on the whole toner particles.

The melting temperature of the release agent and the fixing temperature are different from the fixing temperature [T1] of the rotating body pair of the image forming apparatus by the difference [T1-T2]. The temperature is preferably from 40 ° C to 120 ° C, more preferably from 50 ° C to 110 ° C, and even more preferably from 60 ° C to 100 ° C.
When the set fixing temperature [T1] is higher than the melting temperature [T2] of the release agent and the difference [T1−T2] is 120 ° C. or less, the fixing temperature in the image forming apparatus can be reduced. On the other hand, when the difference [T1−T2] is equal to or higher than 40 ° C., the adhesion of the toner to the fixing member during the fixing of the toner can be suppressed.
However, if the difference [T1−T2] is more than 120 ° C., the release agent is likely to be vaporized during fixing of the toner, and the vaporized release agent is likely to coagulate again in the air, thereby easily generating UFP. . However, even in that case, according to the present embodiment, the amount of UFP generated on the upstream side of the nip is suppressed, and the adhesion of coagulated UFP to the inside of the air supply pipe is suppressed.

-Binder resin-
Examples of the binder resin include styrenes (eg, styrene, parachlorostyrene, α-methylstyrene, etc.) and (meth) acrylates (eg, methyl acrylate, ethyl acrylate, n-propyl acrylate, acrylic acid) n-butyl, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc., ethylenically unsaturated nitriles (for example, acrylonitrile, Methacrylonitrile, etc.), vinyl ethers (eg, vinyl methyl ether, vinyl isobutyl ether, etc.), vinyl ketones (vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone, etc.), olefins (eg, ethylene, propylene Emissions, a homopolymer of a monomer such as butadiene) and the like, or a vinyl-based resin composed of these monomers with two or more combinations copolymer.
As the binder resin, for example, an epoxy resin, a polyester resin, a polyurethane resin, a polyamide resin, a cellulose resin, a polyether resin, a non-vinyl resin such as a modified rosin, a mixture of these and the vinyl resin, or a mixture thereof. A graft polymer obtained by polymerizing a vinyl monomer in the coexistence is also included.
One of these binder resins may be used alone, or two or more thereof may be used in combination.

  From the viewpoint of improving the low-temperature fixability of the toner, it is preferable that a crystalline resin is included as the binder resin.

As the binder resin, a polyester resin is preferable. As the binder resin, a crystalline polyester is preferable.
Examples of the polyester resin include a known amorphous polyester resin. As the polyester resin, a crystalline polyester resin may be used together with the amorphous polyester resin.

Note that the “crystallinity” of the resin refers to having a distinct endothermic peak, not a stepwise endothermic change in differential scanning calorimetry (DSC), and specifically, a temperature increase rate of 10 (° C.) / Min) means that the half width of the endothermic peak is within 10 ° C.
On the other hand, “amorphous” of the resin indicates that the half-value width exceeds 10 ° C., that the resin exhibits a stepwise change in endothermic amount, or that no clear endothermic peak is observed.

-Amorphous polyester resin Examples of the amorphous polyester resin include a polycondensate of a polyvalent carboxylic acid and a polyhydric alcohol. As the amorphous polyester resin, a commercially available product or a synthesized product may be used.

Examples of the polycarboxylic acid include aliphatic dicarboxylic acids (eg, oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, alkenyl succinic acid, adipic acid, sebacic acid, etc.) Alicyclic dicarboxylic acid (eg, cyclohexanedicarboxylic acid, etc.), aromatic dicarboxylic acid (eg, terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, etc.), anhydrides thereof, or lower (eg, having 1 or more carbon atoms) 5 or less) alkyl esters. Among these, as the polyvalent carboxylic acid, for example, an aromatic dicarboxylic acid is preferable.
The polyvalent carboxylic acid may be used in combination with a dicarboxylic acid and a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure. Examples of the trivalent or higher carboxylic acid include trimellitic acid, pyromellitic acid, anhydrides thereof, and lower (for example, having 1 to 5 carbon atoms) alkyl esters thereof.
Polycarboxylic acids may be used alone or in combination of two or more.

Examples of the polyhydric alcohol include aliphatic diols (eg, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, etc.) and alicyclic diols (eg, cyclohexanediol, cyclohexanedimethanol, Hydrogenated bisphenol A, etc.) and aromatic diols (eg, bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct, etc.). Among these, as the polyhydric alcohol, for example, an aromatic diol and an alicyclic diol are preferable, and an aromatic diol is more preferable.
As the polyhydric alcohol, a tri- or higher polyhydric alcohol having a crosslinked structure or a branched structure may be used together with the diol. Examples of the trihydric or higher polyhydric alcohol include glycerin, trimethylolpropane, and pentaerythritol.
Polyhydric alcohols may be used alone or in combination of two or more.

The glass transition temperature (Tg) of the amorphous polyester resin is preferably from 50 ° C to 80 ° C, more preferably from 50 ° C to 65 ° C.
In addition, the glass transition temperature is determined from a DSC curve obtained by differential scanning calorimetry (DSC), and more specifically, described in JIS K 7121-1987 “Method for measuring glass transition temperature” in “Method of measuring glass transition temperature”. Of "extrapolated glass transition onset temperature".

The weight average molecular weight (Mw) of the amorphous polyester resin is preferably from 5,000 to 1,000,000, more preferably from 7000 to 500,000.
The number average molecular weight (Mn) of the amorphous polyester resin is preferably from 2,000 to 100,000.
The molecular weight distribution Mw / Mn of the amorphous polyester resin is preferably from 1.5 to 100, more preferably from 2 to 60.
The weight average molecular weight and the number average molecular weight are measured by gel permeation chromatography (GPC). The molecular weight measurement by GPC is performed using a Tosoh column and TSKgel Super HM-M (15 cm) using a Tosoh GPC / HLC-8120GPC as a measuring device, using a THF solvent. The weight average molecular weight and the number average molecular weight are calculated from the measurement results using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample.

The amorphous polyester resin can be obtained by a well-known manufacturing method. Specifically, for example, it can be obtained by a method in which the polymerization temperature is set to 180 ° C. or higher and 230 ° C. or lower, the pressure in the reaction system is reduced as necessary, and the reaction is carried out while removing water and alcohol generated during condensation.
When the raw material monomers are not dissolved or compatible at the reaction temperature, a high boiling point solvent may be added as a solubilizing agent to dissolve the monomers. In this case, the polycondensation reaction is performed while distilling off the dissolution aid. If a monomer having poor compatibility exists in the copolymerization reaction, the monomer having poor compatibility and the monomer or acid or alcohol to be polycondensed are condensed in advance, and then polymerized together with the main component. It is good to condense.

-Crystalline polyester resin The crystalline polyester resin includes, for example, a polycondensate of a polyvalent carboxylic acid and a polyhydric alcohol. As the crystalline polyester resin, a commercially available product may be used, or a synthesized product may be used.
Here, in order to easily form a crystalline structure, the crystalline polyester resin is preferably a polycondensate using a polymerizable monomer having a straight-chain aliphatic group rather than a polymerizable monomer having an aromatic group.

Examples of the polycarboxylic acid include aliphatic dicarboxylic acids (for example, oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid) Acid, 1,12-dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, etc.), aromatic dicarboxylic acid (for example, phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid) Dibasic acids such as acids), anhydrides thereof, and lower (e.g., 1 to 5 carbon atoms) alkyl esters thereof.
The polyvalent carboxylic acid may be used in combination with a dicarboxylic acid and a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure. Examples of the trivalent carboxylic acid include aromatic carboxylic acids (eg, 1,2,3-benzenetricarboxylic acid, 1,2,4-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, etc.) Anhydrides and lower (e.g., 1 to 5 carbon atoms) alkyl esters thereof are exemplified.
As the polyvalent carboxylic acid, a dicarboxylic acid having a sulfonic acid group or a dicarboxylic acid having an ethylenic double bond may be used in combination with these dicarboxylic acids.
Polycarboxylic acids may be used alone or in combination of two or more.

Examples of the polyhydric alcohol include an aliphatic diol (for example, a linear aliphatic diol having a carbon number of 7 to 20 in a main chain portion). Examples of the aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8- Octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18- Octadecanediol, 1,14-eicosandecanediol and the like can be mentioned. Among them, as the aliphatic diol, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol are preferable.
As the polyhydric alcohol, a tri- or higher-valent alcohol having a crosslinked structure or a branched structure may be used together with the diol. Examples of the trivalent or higher alcohol include glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol.
Polyhydric alcohols may be used alone or in combination of two or more.

  Here, the polyhydric alcohol may have an aliphatic diol content of at least 80 mol%, preferably at least 90 mol%.

The melting temperature of the crystalline polyester resin is preferably from 50 ° C to 100 ° C, more preferably from 55 ° C to 90 ° C, and still more preferably from 60 ° C to 85 ° C.
The melting temperature is determined from the DSC curve obtained by differential scanning calorimetry (DSC) according to the “melting peak temperature” described in JIS K7121-1987 “Method of measuring the melting temperature of plastics”.

  The weight average molecular weight (Mw) of the crystalline polyester resin is preferably from 6,000 to 35,000.

  The crystalline polyester resin is obtained by a well-known manufacturing method, for example, similarly to the amorphous polyester resin.

  The content of the binder resin is, for example, preferably from 40% by mass to 95% by mass, more preferably from 50% by mass to 90% by mass, and more preferably from 60% by mass to 85% by mass, based on the whole toner particles. More preferred.

  In addition, the content of the crystalline resin is preferably 3% by mass or more and 20% by mass or less, more preferably 5% by mass or more and 15% by mass or less based on the whole toner particles, from the viewpoint of enhancing the low-temperature fixability of the toner. .

-Coloring agent-
Examples of the coloring agent include carbon black, chrome yellow, Hansa yellow, benzidine yellow, slen yellow, quinoline yellow, pigment yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watch young red, permanent red, brilliant carmine 3B, and brilliant. Carmine 6B, Dupont Oil Red, Pyrazolone Red, Lisor Red, Rhodamine B Lake, Lake Red C, Pigment Red, Rose Bengal, Aniline Blue, Ultramarine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Pigment Blue, Phthalocyanine Green, Various pigments such as malachite green oxalate, or acridine, xanthene, Various dyes such as benzoquinone, azine, anthraquinone, thioindico, dioxazine, thiazine, azomethine, indico, phthalocyanine, aniline black, polymethine, triphenylmethane, diphenylmethane, and thiazole And the like.
One type of colorant may be used alone, or two or more types may be used in combination.

  The colorant may be a surface-treated colorant as necessary, or may be used in combination with a dispersant. In addition, a plurality of colorants may be used in combination.

  The content of the colorant is, for example, preferably from 1% by mass to 30% by mass, and more preferably from 3% by mass to 15% by mass, based on the whole toner particles.

-Other additives-
Examples of the other additives include well-known additives such as a magnetic substance, a charge control agent, and an inorganic powder. These additives are contained in the toner particles as internal additives.

-Characteristics of toner particles-
The toner particles may be toner particles having a single-layer structure, or toner particles having a so-called core-shell structure composed of a core material (core particles) and a coating layer (shell layer) covering the core material. You may.
Here, the toner particles having a core-shell structure include, for example, a core material including a binder resin and other additives such as a colorant and a release agent as needed, and a binder resin. And a coating layer configured.

  The volume average particle diameter (D50v) of the toner particles is preferably 2 μm or more and 10 μm or less, more preferably 4 μm or more and 8 μm or less.

Various average particle diameters and various particle size distribution indexes of the toner particles were measured using Coulter Multisizer II (manufactured by Beckman Coulter), and the electrolytic solution was measured using ISOTON-II (manufactured by Beckman Coulter). You.
In the measurement, 0.5 mg or more and 50 mg or less of a measurement sample are added to 2 ml of a 5% aqueous solution of a surfactant (preferably sodium alkylbenzene sulfonate) as a dispersant. This is added to 100 ml or more and 150 ml or less of the electrolytic solution.
The electrolyte in which the sample is suspended is subjected to dispersion treatment for 1 minute by an ultrasonic disperser, and the particle size distribution of particles having a particle size in the range of 2 μm to 60 μm is measured using a Coulter Multisizer II using an aperture having an aperture diameter of 100 μm. Measure. The number of particles to be sampled is 50,000.
A volume distribution and a number are plotted from the smaller diameter side for the particle size range (channel) divided based on the measured particle size distribution, and the particle size at which the accumulation becomes 16% is determined as the volume particle size D16v and the number particle size. D16p, the particle diameter at which the accumulation is 50% is defined as a volume average particle diameter D50v, the accumulation number average particle diameter D50p, and the particle diameter at which the accumulation is 84% are defined as volume particle diameter D84v and number particle diameter D84p.
Using these, the volume particle size distribution index (GSDv) is calculated as (D84v / D16v) ^1/2 , and the number particle size distribution index (GSDp) is calculated as (D84p / D16p) ^1/2 .

The shape factor SF1 of the toner particles is preferably from 140 to 155, more preferably from 143 to 153, even more preferably from 145 to 151.
Here, when the toner particles are produced by a pulverizing method such as a kneading and pulverizing method, the shape is irregular, and for example, the shape factor SF1 is 140 or more. In the case of toner particles having a shape factor SF1 of 140 or more, the release agent is likely to be exposed on the surface due to the manufacturing method. The release agent exposed on the surface is easily vaporized by heat when fixing the toner, and as a result, UFP is easily generated. However, even in that case, according to the present embodiment, the amount of UFP generated on the upstream side of the nip is suppressed, and the adhesion of coagulated UFP to the inside of the air supply pipe is suppressed.

The shape factor SF1 is obtained by the following equation.
Formula: SF1 = (ML ² / A) × (π / 4) × 100
In the above formula, ML indicates the absolute maximum length of the toner, and A indicates the projected area of the toner.
Specifically, the shape factor SF1 is quantified by mainly analyzing a microscope image or a scanning electron microscope (SEM) image using an image analyzer, and is calculated as follows. That is, the optical microscope image of the particles scattered on the slide glass surface is taken into a Luzex image analyzer by a video camera, the maximum length and the projected area of 100 particles are obtained, calculated by the above equation, and the average value thereof is obtained. can get.

The toluene-insoluble content of the toner particles is preferably from 25% by mass to 40% by mass, more preferably from 28% by mass to 38% by mass, and still more preferably from 30% by mass to 35% by mass.
When the toluene insoluble content of the toner particles is in the above range, the release agent is confined in the toner particles, and the exposure of the release agent to the surface is suppressed. As a result, the amount of UFP generated on the upstream side of the nip is easily suppressed, and the adhesion of coagulated UFP to the inside of the air supply pipe is easily suppressed.

  Here, the toluene-insoluble portion of the toner particles is a component of the toner particles that are insoluble in toluene. That is, the toluene-insoluble component is an insoluble component containing a binder resin component (particularly, a high molecular weight component of the binder resin) insoluble in toluene as a main component (for example, 50% by mass or more of the whole). This toluene-insoluble content can be said to be an index of the content of the crosslinked resin contained in the toner.

The toluene-insoluble content is a value measured by the following method.
1 g of the weighed toner particles (or toner) is put into the weighed glass fiber cylindrical filter paper, and is attached to an extraction tube of a heated Soxhlet extraction device. Then, toluene is injected into the flask and heated to 110 ° C. using a mantle heater. In addition, the periphery of the extraction tube is heated to 125 ° C. using a heating heater attached to the extraction tube. Extraction is performed at a reflux rate such that the extraction cycle is performed once within a range of 4 minutes to 5 minutes. After extraction for 10 hours, the cylindrical filter paper and the toner residue are taken out, dried, and weighed.
Then, the formula: toner particle (or toner) residue amount (mass%) = [(cylinder filter paper amount + toner residue amount) (g) -cylinder filter paper amount (g)] ÷ toner particle (or toner) mass (g) × Based on 100, the residual amount (% by mass) of the toner particles (or toner) is calculated, and the residual amount (% by mass) of the toner particles (or toner) is defined as a toluene-insoluble content (% by mass).
The toner particle (or toner) residue is composed of an inorganic substance such as a colorant and an external additive, and a high molecular weight component of a binder resin. Further, when the toner particles contain a release agent, extraction by heating is performed, so that the release agent is a toluene-soluble component.

  The toluene-insoluble content of the toner particles may be, for example, a method of forming a crosslinked structure or a branched structure by adding a crosslinking agent to a polymer component having a reactive functional group at the terminal, and 2) at the terminal of the binder resin. It is adjusted by a method of forming a crosslinked structure or a branched structure with a polyvalent metal ion in a polymer component having an ionic functional group, 3) a method of elongating a resin chain length by treatment with an isocyanate or the like, or a method of forming a branch.

(External additives)
Examples of the external additive include inorganic particles. As the inorganic particles, SiO ₂ , TiO ₂ , Al ₂ O ₃ , CuO, ZnO, SnO ₂ , CeO ₂ , Fe ₂ O ₃ , MgO, BaO, CaO, K ₂ O, Na ₂ O, ZrO ₂ , CaO. SiO ₂ , K ₂ O. (TiO ₂ ) n, Al ₂ O ₃ .2SiO ₂ , CaCO ₃ , MgCO ₃ , BaSO ₄ , MgSO _{4 and the} like.

The surface of the inorganic particles as an external additive is preferably subjected to a hydrophobic treatment. The hydrophobic treatment is performed, for example, by immersing the inorganic particles in a hydrophobic treatment agent. The hydrophobizing agent is not particularly limited, and examples thereof include a silane coupling agent, a silicone oil, a titanate coupling agent, and an aluminum coupling agent. These may be used alone or in combination of two or more.
The amount of the hydrophobizing agent is usually, for example, 1 part by mass or more and 10 parts by mass or less based on 100 parts by mass of the inorganic particles.

  Examples of the external additive include resin particles (resin particles such as polystyrene, polymethyl methacrylate (PMMA), and melamine resin), a cleaning activator (for example, a metal salt of a higher fatty acid represented by zinc stearate, a fluoropolymer, Particles).

  The external additive amount of the external additive is, for example, preferably from 0.01% by mass to 5% by mass, more preferably from 0.01% by mass to 2.0% by mass, based on the toner particles.

(Method of manufacturing toner)
Next, a method for manufacturing a toner according to the exemplary embodiment will be described.
The toner according to the exemplary embodiment is obtained by externally adding an external additive to the toner particles after manufacturing the toner particles.

The toner particles may be manufactured by any of a dry manufacturing method (for example, a kneading and pulverizing method) and a wet manufacturing method (for example, an aggregation and coalescence method, a suspension polymerization method, and a dissolution suspension method). The production method of the toner particles is not particularly limited, and a known production method is employed.
Among these, it is preferable to obtain the toner particles by the aggregation and coalescence method.

-Aggregation coalescence method Specifically, for example, when the toner particles are manufactured by the aggregation coalescence method,
A step of preparing a resin particle dispersion in which resin particles serving as a binder resin are dispersed (resin particle dispersion preparation step); and a step of mixing a resin particle dispersion in the resin particle dispersion (if necessary, (In the dispersion), aggregating the resin particles (other particles as necessary) to form aggregated particles (aggregated particle forming step), and heating the aggregated particle dispersion in which the aggregated particles are dispersed. And a step of fusing and coalescing the aggregated particles to form toner particles (fusing / coalescing step), thereby producing toner particles.

Hereinafter, details of each step will be described.
In the following description, a method for obtaining toner particles containing a colorant and a release agent will be described, but the colorant and the release agent are used as needed. Of course, other additives other than the colorant and the release agent may be used.

-Resin particle dispersion preparation process-
First, together with a resin particle dispersion in which resin particles serving as a binder resin are dispersed, for example, a colorant particle dispersion in which colorant particles are dispersed, and a release agent particle dispersion in which release agent particles are dispersed are prepared. I do.

  Here, the resin particle dispersion is prepared, for example, by dispersing resin particles in a dispersion medium with a surfactant.

Examples of the dispersion medium used for the resin particle dispersion include an aqueous medium.
Examples of the aqueous medium include water such as distilled water and ion-exchanged water, and alcohols. These may be used alone or in combination of two or more.

Examples of the surfactant include anionic surfactants such as sulfate ester type, sulfonate type, phosphate ester type and soap type; cationic surfactants such as amine salt type and quaternary ammonium salt type; polyethylene glycol And non-ionic surfactants such as alkylphenol ethylene oxide adducts and polyhydric alcohols. Among these, anionic surfactants and cationic surfactants are particularly mentioned. The nonionic surfactant may be used in combination with an anionic surfactant or a cationic surfactant.
One type of surfactant may be used alone, or two or more types may be used in combination.

Examples of the method for dispersing the resin particles in the dispersion medium in the resin particle dispersion include general dispersion methods such as a rotary shearing homogenizer, a ball mill having a medium, a sand mill, and a dyno mill. Depending on the type of the resin particles, the resin particles may be dispersed in the resin particle dispersion using, for example, a phase inversion emulsification method.
The phase inversion emulsification method is a method in which a resin to be dispersed is dissolved in a hydrophobic organic solvent in which the resin is soluble, and a base is added to an organic continuous phase (O phase) for neutralization. (W phase), a method of converting the resin from W / O to O / W (so-called phase inversion) to form a discontinuous phase, and dispersing the resin in an aqueous medium in a particulate form. It is.

The volume average particle size of the resin particles dispersed in the resin particle dispersion is, for example, preferably 0.01 μm or more and 1 μm or less, more preferably 0.08 μm or more and 0.8 μm or less, further preferably 0.1 μm or more and 0.6 μm or less. preferable.
The volume average particle size of the resin particles is determined by using a particle size distribution obtained by measurement using a laser diffraction type particle size distribution measuring device (for example, LA-700, manufactured by HORIBA, Ltd.). The volume-average particle size D50v is measured by subtracting the cumulative distribution from the small particle size side with respect to the volume and determining the particle size at which 50% of the total particles are accumulated. In addition, the volume average particle diameter of the particles in other dispersion liquids is measured similarly.

  The content of the resin particles contained in the resin particle dispersion is, for example, preferably from 5% by mass to 50% by mass, and more preferably from 10% by mass to 40% by mass.

  In the same manner as the resin particle dispersion, for example, a colorant particle dispersion and a release agent particle dispersion are also prepared. In other words, regarding the volume average particle diameter of the particles in the resin particle dispersion, the dispersion medium, the dispersion method, and the content of the particles, the colorant particles dispersed in the colorant particle dispersion, and the release agent particle dispersion The same applies to the releasing agent particles to be dispersed.

-Aggregated particle formation process-
Next, the colorant particle dispersion and the release agent particle dispersion are mixed together with the resin particle dispersion.
Then, in the mixed dispersion, the resin particles, the colorant particles, and the release agent particles having a diameter close to the diameter of the intended toner particles by hetero-aggregating the resin particles, the colorant particles, and the release agent particles, To form aggregated particles.

Specifically, for example, after adding a flocculant to the mixed dispersion, adjusting the pH of the mixed dispersion to acidic (for example, pH of 2 or more and 5 or less), and adding a dispersion stabilizer as necessary, Heating to a temperature of the glass transition temperature of the resin particles (specifically, for example, the glass transition temperature of the resin particles −30 ° C. or more and the glass transition temperature of −10 ° C. or less) to aggregate the particles dispersed in the mixed dispersion. Form aggregated particles.
In the aggregated particle forming step, for example, the above-mentioned aggregating agent is added at room temperature (for example, 25 ° C.) while stirring the mixed dispersion with a rotary shearing homogenizer, and the pH of the mixed dispersion is made acidic (for example, when the pH is 2 or more and 5 or less). ), And the above-mentioned heating may be performed after adding a dispersion stabilizer as needed.

Examples of the coagulant include a surfactant having a polarity opposite to that of the surfactant used as a dispersant added to the mixed dispersion, an inorganic metal salt, and a divalent or higher valent metal complex. In particular, when a metal complex is used as the aggregating agent, the amount of the surfactant used is reduced, and the charging characteristics are improved.
If necessary, an additive that forms a complex or a similar bond with the metal ion of the flocculant may be used. As this additive, a chelating agent is suitably used.

Examples of the inorganic metal salt include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate; and inorganic salts such as polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide. And metal salt polymers.
As the chelating agent, a water-soluble chelating agent may be used. Examples of the chelating agent include oxycarboxylic acids such as tartaric acid, citric acid and gluconic acid, iminodiic acid (IDA), nitrilotriacetic acid (NTA), and ethylenediaminetetraacetic acid (EDTA).
The addition amount of the chelating agent is, for example, preferably from 0.01 to 5.0 parts by mass, more preferably from 0.1 to less than 3.0 parts by mass, per 100 parts by mass of the resin particles.

-Fusion and coalescence process-
Next, the aggregated particle dispersion in which the aggregated particles are dispersed is heated, for example, to a temperature equal to or higher than the glass transition temperature of the resin particles (e.g., equal to or higher than 10 to 30 ° C. higher than the glass transition temperature of the resin particles). To form toner particles.

Through the above steps, toner particles are obtained.
In addition, after obtaining the aggregated particle dispersion in which the aggregated particles are dispersed, the aggregated particle dispersion and the resin particle dispersion in which the resin particles are dispersed are further mixed, and the resin particles are further mixed on the surface of the aggregated particles. Aggregating so as to adhere to form second aggregated particles, and heating the second aggregated particle dispersion in which the second aggregated particles are dispersed to fuse and unite the second aggregated particles. And forming a toner particle having a core / shell structure.

Here, after completion of the fusion / coalescing step, the toner particles formed in the solution are subjected to a known washing step, solid-liquid separation step, and drying step to obtain dried toner particles.
In the washing step, it is preferable to sufficiently perform replacement washing with ion-exchanged water from the viewpoint of chargeability. The solid-liquid separation step is not particularly limited, but is preferably performed by suction filtration, pressure filtration, or the like from the viewpoint of productivity. The drying step is not particularly limited, but freeze-drying, flash drying, fluidized drying, vibration-type fluidized drying, and the like are preferably performed from the viewpoint of productivity.

  The toner according to the exemplary embodiment is manufactured by, for example, adding an external additive to the obtained toner particles in a dry state and mixing. The mixing may be performed by, for example, a V blender, a Henschel mixer, a Loedige mixer, or the like. Further, if necessary, coarse particles of the toner may be removed using a vibration sieving machine, a wind sieving machine, or the like.

-Kneading and crushing method The toner particles in the present embodiment may be produced by a crushing method such as a kneading and crushing method. When manufactured by a pulverization method, the shape is irregular, and for example, the shape factor SF1 is in the above-described range. Then, since the release agent is easily exposed on the surface due to the manufacturing method, UFP is easily generated. However, even in that case, according to the present embodiment, the amount of UFP generated on the upstream side of the nip is suppressed, and the adhesion of coagulated UFP to the inside of the air supply pipe is suppressed.

The kneading and pulverizing method is a method for producing toner particles by melt-kneading a binder resin and a release agent containing at least a specific paraffin-based wax having a melting temperature in the above-described range, followed by pulverization and classification. . In the kneading and pulverizing method, for example, a kneading step of melt-kneading components including a binder resin and a release agent, a cooling step of cooling the melt-kneaded material, a pulverizing step of pulverizing the kneaded material after cooling, and a pulverized material And a classification step of classifying the toner particles to produce toner particles.
Hereinafter, the details of each step of the kneading and pulverizing method will be described.

-Kneading process-
The kneading step is a step of melt-kneading constituent components (resin particle forming material) containing a binder resin and a release agent to obtain a kneaded product.
Examples of the kneading machine used in the kneading step include a three-roll type, a single screw type, a twin screw type, and a Banbury mixer type.
Further, the melting temperature may be determined according to the types and the mixing ratios of the binder resin and the release agent to be kneaded.

-Cooling process-
The cooling step is a step of cooling the kneaded material formed in the kneading step.
In the cooling step, in order to maintain a dispersed state immediately after the completion of the kneading step, it is preferable to cool the kneaded material at the end of the kneading step to 40 ° C. or lower at an average temperature lowering rate of 4 ° C./sec or more.
In addition, the average cooling rate refers to the average value of the rate at which the temperature of the kneaded material is lowered from the temperature of the kneaded material to 40 ° C. at the end of the kneading step.

  As a cooling method in the cooling step, for example, a method using a rolling roll circulating cold water or brine, a sandwiching-type cooling belt, or the like can be used. When the cooling is performed by the above method, the cooling rate is determined by the speed of the rolling roll, the flow rate of the brine, the supply amount of the kneaded material, the slab thickness at the time of rolling the kneaded material, and the like. The slab thickness is preferably 1 mm or more and 3 mm or less.

-Pulverizing process-
Particles are formed by pulverizing the kneaded material cooled in the cooling step in the pulverizing step.
In the pulverizing step, for example, a mechanical pulverizer, a jet pulverizer, or the like is used.

-Classification process-
The pulverized product (particles) obtained in the pulverizing step may be subjected to classification in a classification step, if necessary.
In the classification process, a conventionally used centrifugal classifier, inertial classifier, or the like is used, and fine powder (particles smaller than the target range) and coarse powder (particles in the target range) are used. Larger particles) are removed.

  The toner according to the exemplary embodiment is manufactured by, for example, adding an external additive to the obtained toner particles in a dry state and mixing. The mixing may be performed by, for example, a V blender, a Henschel mixer, a Lodige mixer, or the like. Further, if necessary, coarse particles of the toner may be removed using a vibration sieving machine, a wind sieving machine, or the like.

(Developer)
The developer according to the embodiment includes at least the toner according to the embodiment.
The developer in the present embodiment may be a one-component developer containing only the toner in the present embodiment, or a two-component developer in which the toner and a carrier are mixed.

The carrier is not particularly limited, and includes known carriers. Examples of the carrier include a coated carrier in which a core resin made of a magnetic powder is coated with a coating resin; a magnetic powder-dispersed carrier in which a magnetic powder is dispersed and blended in a matrix resin; a porous magnetic powder impregnated with a resin; And a resin-impregnated carrier.
Note that the magnetic powder-dispersed carrier and the resin-impregnated carrier may be a carrier in which constituent particles of the carrier are used as a core material and the core material is coated with a coating resin.

  Examples of the magnetic powder include magnetic metals such as iron, nickel, and cobalt, and magnetic oxides such as ferrite and magnetite.

Examples of the coating resin and the matrix resin include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, and styrene-acrylate. Examples thereof include a copolymer, a straight silicone resin containing an organosiloxane bond or a modified product thereof, a fluororesin, a polyester, a polycarbonate, a phenol resin, and an epoxy resin.
Note that the coating resin and the matrix resin may contain other additives such as conductive particles.
Examples of the conductive particles include particles such as metals such as gold, silver and copper, carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate, and potassium titanate.

Here, in order to coat the surface of the core material with the coating resin, a method of coating the coating resin with a coating layer forming solution in which various additives are dissolved in an appropriate solvent, if necessary, and the like can be mentioned. The solvent is not particularly limited, and may be selected in consideration of the coating resin to be used, suitability for application, and the like.
Specific resin coating methods include an immersion method in which the core material is immersed in a solution for forming the coating layer, a spray method in which the solution for forming the coating layer is sprayed on the surface of the core material, and a method in which the core material is suspended by flowing air. Examples thereof include a fluidized bed method in which a coating layer forming solution is sprayed, and a kneader coater method in which a carrier core material and a coating layer forming solution are mixed in a kneader coater to remove a solvent.

  The mixing ratio (mass ratio) of the toner and the carrier in the two-component developer is preferably toner: carrier = 1: 100 to 30: 100, and more preferably 3: 100 to 20: 100.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. In the following, “parts” are based on mass unless otherwise specified.

<Preparation of crystalline resin (A)>
First, 100 parts of dimethyl sebacate, 67.8 parts of hexanediol, and 0.10 part of dibutyltin oxide are placed in a three-necked flask, and water generated during the reaction is removed outside the system under a nitrogen atmosphere. After the reaction at 185 ° C. for 5 hours, the temperature was increased to 220 ° C. while gradually reducing the pressure, and the reaction was continued for 6 hours, followed by cooling. Thus, a crystalline resin (A) having a weight average molecular weight of 33,700 was prepared.

<Preparation of amorphous resin>
(Preparation of amorphous resin (1))
In a three-necked flask, 61 parts of dimethyl terephthalate, 75 parts of dimethyl fumarate, 34 parts of dodecenylsuccinic anhydride, 16 parts of trimellitic acid, 137 parts of an adduct of bisphenol A ethylene oxide, and 137 parts of bisphenol A propylene oxide were added. 191 parts of the product and 0.3 parts of dibutyltin oxide were added, and the mixture was reacted at 180 ° C. for 3 hours while removing water generated by the reaction under a nitrogen atmosphere, and then gradually reduced in pressure. The temperature was raised to 280 ° C., and after reacting for 2 hours, the mixture was cooled. Thus, an amorphous resin (1) having a weight average molecular weight of 19000 was prepared.

(Preparation of amorphous resin (2))
Except that 60 parts of dimethyl terephthalate, 74 parts of dimethyl fumarate, 30 parts of dodecenylsuccinic anhydride, and 22 parts of trimellitic acid were used, the same procedure as in the preparation of the amorphous resin (1) was applied to the amorphous resin (2). Was prepared. The weight average molecular weight of the amorphous resin (2) was 19,500.

(Preparation of amorphous resin (3))
Except that 60 parts of dimethyl terephthalate, 70 parts of dimethyl fumarate, 29 parts of dodecenylsuccinic anhydride and 29 parts of trimellitic acid were used, the same procedure as in the preparation of the amorphous resin (1) was applied to the amorphous resin (3). Was prepared. The weight average molecular weight of the amorphous resin (3) was 18,200.

(Preparation of amorphous resin (4))
Except that 55 parts of dimethyl terephthalate, 64 parts of dimethyl fumarate, 27 parts of dodecenyl succinic anhydride, and 46 parts of trimellitic acid were used, the same procedure as in the preparation of the amorphous resin (1) was carried out. Was prepared. The weight average molecular weight of the amorphous resin (3) was 17,200.

<Preparation of toner>
(Production of toner particles (1))
79 parts of the amorphous resin (1), 7 parts of a colorant (CI Pigment Blue 15: 1), and 5 parts of a release agent (paraffin wax, a melting temperature of 73 ° C., manufactured by Nippon Seiro Co., Ltd.) , And 8 parts of the crystalline resin (A) (melting temperature: 71 ° C.) were charged into a Henschel mixer (manufactured by Nippon Coke Industry Co., Ltd.) and stirred and mixed at a peripheral speed of 15 m / sec for 5 minutes. Was melt-kneaded with an extruder-type continuous kneader.
Here, the setting conditions of the extruder were as follows: the supply side temperature was 160 ° C., the discharge side temperature was 130 ° C., the supply side temperature of the cooling roll was 40 ° C., and the discharge side temperature was 25 ° C. In addition, the temperature of the cooling belt was set to 10 ° C.
After cooling the obtained melt-kneaded material, it was roughly pulverized using a hammer mill, and then finely pulverized to 6.5 μm using a jet pulverizer (manufactured by Nippon Pneumatic Industrial Co., Ltd.), and further, an elbow jet classifier. (Model: EJ-LABO, manufactured by Nippon Steel Mining Co., Ltd.) to obtain toner particles (1) having a volume average particle diameter of 6.9 μm.
The shape factor SF1 of the toner particle (1) was 145, and the toluene-insoluble content was 25% by mass.

(Production of toner particles (2))
A toner particle (2) having a volume average particle diameter of 6.8 μm was obtained in the same manner as in the preparation of the toner (1) except that the amorphous resin (2) was used instead of the amorphous resin (1). .
The shape factor SF1 of the toner particles (2) was 147, and the toluene-insoluble content was 29% by mass.

(Production of Toner Particles (3))
Toner particles (3) having a volume average particle diameter of 7.0 μm were obtained in the same manner as in the preparation of toner (1) except that amorphous resin (3) was used instead of amorphous resin (1).
The shape factor SF1 of the toner particles (3) was 149, and the toluene-insoluble content was 35% by mass.

(Production of Toner Particles (4))
Toner particles (4) having a volume average particle diameter of 7.3 μm were obtained in the same manner as in the preparation of toner (1) except that amorphous resin (4) was used instead of amorphous resin (1).
The shape factor SF1 of the toner particles (4) was 151, and the toluene-insoluble content was 40% by mass.

(Production of Toner Particles (5))
Toner particles (5) having a volume average particle diameter of 6.8 μm were obtained in the same manner as in the preparation of toner (1), except that ceresin wax (melting temperature: 92 ° C.) was used as a release agent.
The shape factor SF1 of the toner particles (5) was 148, and the toluene-insoluble content was 33% by mass.

(Preparation of Toner Particle (C1))
Except that paraffin wax (manufactured by Baker Petrolite: polywax 725, melting temperature 105 ° C.) was used as the release agent, toner particles (C1 ) Got.
The shape factor SF1 of the toner particles (C1) was 146, and the toluene-insoluble content was 45% by mass.

(Production of toner and developer)
Using a Henschel mixer (manufactured by Mitsui Miike Seisakusho), 100 parts of each toner particle and 1.2 parts of commercially available fumed silica RX50 (manufactured by Nippon Aerosil) as an external additive were used at a peripheral speed of 30 m / s for 5 minutes. Under the conditions, toners (1) to (5) and (C1) were obtained.
Subsequently, 8 parts of each of the obtained toners and 100 parts of the carrier were mixed to prepare developers (1) to (5) and (C1), respectively.
The carrier was 100 parts of ferrite particles (volume average particle size: 50 μm), 14 parts of toluene, and a styrene-methyl methacrylate copolymer (component ratio: styrene / methyl methacrylate = 90/10, weight average molecular weight Mw = 80000). 2) was prepared by first dispersing the above components except for the ferrite particles by stirring with a stirrer for 10 minutes to prepare a coating liquid. Then, the coating liquid and the ferrite particles were vacuum-degassed kneader (manufactured by Inoue Seisakusho). ), Stirred at 60 ° C. for 30 minutes, degassed by depressurizing while further heating, dried, and then sieved at 105 μm.

<Examples A1 to A5>
Using an image forming apparatus (manufactured by Fuji Xerox Co., Ltd., product name "DocuColor 1450 GA"), the fixing apparatus and the air supply pipe having the configurations shown in FIGS. did. Further, the filter provided at the exhaust port of the image forming apparatus was removed. Then, the developer shown in Table 1 was stored in the developing device of the image forming apparatus.

・ Fixing device A
Specifically, a fixing device including the heating belt 62 and the pressure roll 61 shown in FIGS. 2 to 5 was used.
As the heating belt 62, a belt member composed of a single layer of a polyimide resin layer was used.
The fixing temperature of the heating belt 62 was set to 160 ° C., and the length (so-called nip width) of the nip N formed by the heating belt 62 and the pressure roll 61 in the paper K transport direction was set to 7 mm.
Table 1 shows the difference [T1-T2] between the fixing temperature [T1] of the heating belt 62 and the melting temperature [T2] of the release agent contained in the toner particles in the developer.

・ Air pipe A
Specifically, an air supply pipe provided with the duct 100 shown in FIGS. 2 to 5 was installed.
When viewed from the axial direction of the heating belt 62, the shape of the air supply inlet 102A is a shape that spreads from the inlet side air supply part 102B toward the nip N, and the surface forming the inlet faces the direction of the nip N. I have.
The position where the end of the air supply inlet 102A on the side close to the heating belt 62 is installed is 30 mm from the upstream end of the nip N, 20 mm from the surface of the heating belt 62, and from the paper K transport path. Is 20 mm.
The position where the end of the air supply inlet 102A farther from the heating belt 62 is installed is a distance of 40 mm from the upstream end of the nip N and a distance of 30 mm from the paper K transport path.

When viewed from the paper K transport direction, the shape of the air supply inlet 102A is a shape that becomes wider as approaching the paper K transport path, and the length in the width direction is longer than the length of the paper K in the width direction.
The width of the air inlet 102A is longer by 10 mm on both ends than the length of the paper K in the width direction.

When viewed from the axial direction of the heating belt 62, the shape of the air supply outlet 106A is a shape that expands from the outlet side air supply unit 106B toward the paper K transport path. The surface forming the outlet is parallel to the sheet K transport path, and the air supply outlet 106A is arranged to face the sheet K passing through the transport path.
The position where the air supply outlet 106A is installed is 20 mm from the paper K transport path.
The distance in the paper K transport direction between the end of the air supply outlet 106A closer to the heating belt 62 and the downstream end of the nip N (that is, the distance between the downstream end of the nip N and the air supply outlet 106A on the paper K transport path). The distance from the position corresponding to the end) is 10 mm. In other words, the air supply outlet 106A is provided at a position where exhaust is performed from the air supply outlet 106A before the toner image is completely solidified on the sheet K after the nip N has been inserted.
The position where the end of the air supply outlet 106 </ b> A on the side close to the heating belt 62 is installed is 20 mm from the surface of the heating belt 62.

When viewed from the paper K transport direction, the shape of the air supply outlet 106A is a shape that becomes wider as approaching the paper K transport path, and the length in the width direction is shorter than the length in the width direction of the paper K.
The width of the air supply outlet 106A is shorter by 10 mm on both ends than the length of the paper K in the width direction.

The shapes of the inlet-side air supply unit 102B, the belt-side air supply unit 104, and the outlet-side air supply unit 106B are circular tubes having a true circular cross section. Portions other than the bent portion (bent portion) in the inlet-side air supply section 102B, the belt-side air supply section 104, and the outlet-side air supply section 106B have the same cross-sectional area.
The outer diameter of the inlet air supply unit 102B, the belt air supply unit 104, and the outlet air supply unit 106B other than the bent portion (bent portion) is 20 mm.
The distance between the surface of the in-belt air supply unit 104 and the surface of the heating element 64 is 20 mm.

  The duct 100 is provided with fans 108A and 108B at the positions shown in FIG. 5, whereby an airflow from the air inlet 102A to the air outlet 106A is formed.

The transport speed of the paper K is 121 mm / sec.
The flow velocity (air supply speed) of the air moving in the duct 100 is determined by the time required for the air entering from the air supply inlet 102A to be discharged from the air supply outlet 106A and reach the paper K transport path, and the upstream side of the nip N. The time required for the sheet K inserted into the end to reach the position where the air discharged from the air supply outlet 106A reaches is set to be synchronized.

<Examples B1 to B5>
An image forming apparatus having the same configuration as in Examples A1 to A5 was prepared, except that an apparatus provided with the following air supply pipe B was used instead of the air supply pipe A installed in Examples A1 to A5.

・ Air pipe B
A duct having the same configuration as the air supply pipe A was installed except that the outer diameter of the air supply part of the duct 100 was changed.
The outer diameter of the inlet air supply unit 102B, the belt air supply unit 104, and the outlet air supply unit 106B other than the bent portion (the bent portion) is 5 mm.

<Comparative Example 1>
An image forming apparatus having the same configuration as in Examples A1 to A5 was prepared except that the apparatus provided with the following air supply pipe C was used instead of the air supply pipe A installed in Examples A1 to A5.

・ Air pipe C
A duct having the same configuration as the air supply pipe A was installed, except that the duct 100 was not arranged to pass through the inner peripheral side of the heating belt 62.
Specifically, an air supply inlet and an air supply outlet having the same position and the same shape as the air supply pipe A are provided. However, the air supply section connecting the air supply inlet and the air supply outlet is arranged so as not to pass through the inner peripheral side of the heating belt, the outer diameter of the ventilation section is the same as that of the air supply pipe A, and the ventilation section has a ventilation section. The air supply unit was set so that the length in the direction (that is, the distance to the air supply inlet and the air supply outlet) was the same as that of the air supply pipe A. For this reason, the air supply section is arranged so as to largely bypass the outer peripheral side of the heating belt and connect the air supply inlet and the air supply outlet.

<Reference Example 1>
In Example A1, an image forming apparatus having the same configuration as that of Example A1 was prepared, except that the developer contained in the developing device of the image forming apparatus was changed to the developer (C1).

<Evaluation>
(Evaluation of UFP off-machine emissions)
Under an environment of a temperature of 22 ° C. and a humidity of 55% RH, an image having an image density of 100% was continuously formed on 1000 sheets of A3 size paper. During the image formation, the particle emission rate (PER _{10 PW} ) of UFP discharged from the image forming apparatus was measured at Fuji Xerox International Verification Center based on RAL UZ-171.
Based on the value of the measured particle emission rate [unit (number of particles / 10 minutes)], evaluation was made in three stages of G1 to G3. It should be noted that the comparative example 1 was provided with a device having no air supply pipe (duct) as a reference (G3) for relative evaluation. G1 has the smallest value, indicating that UFP is small.
-UFP emissions-
A: G1
B: G2
C: G3

(Evaluation of adhesion in UFP air duct)
Further, in the above-mentioned UFP out-of-machine discharge evaluation test, the amount of UFP adhering to the air supply pipe was evaluated according to the following criteria.

-Attached amount in UFP air line-
A: No adhesion B: Slight adhesion C: Aggregated adhesion D: Clogging due to adhesion

From the above results, it was found that in each of the examples, the adhesion of the coagulated material of the UPF derived from the release agent contained in the toner to the inside of the air supply pipe was suppressed as compared with the comparative example.
In the reference example, since the melting temperature of the release agent contained in the toner exceeded 100 ° C., the amount of UPF derived from the release agent contained in the toner was small.

1Y, 1M, 1C, 1K Image forming unit 10 Image forming device 50 Fixing device 61 Pressure roll 61A Core 61B Elastic layer 61C Surface layer 62 Heating belt 63 Belt running guide 64 Heating element 66 Belt running auxiliary guide 69 Sliding member 100 Duct 102A Air supply inlet 102B Inlet side air supply unit 104 In-belt air supply unit 106A Air supply outlet 106B Outlet side air supply units 108A, 108B Fan 111 Photoconductor 112 Charger 113 Laser exposure unit 114 Developing unit 115 Intermediate transfer belt 116 Primary transfer Roll 117 Photoconductor cleaner 118 Primary transfer unit 120 Secondary transfer unit 122 Secondary transfer roll 125 Back roll 126 Power supply roll 131 Driving roll 132 Support roll 133 Tension applying roll 134 Cleaning back roll 135 Intermediate transfer belt cleaner 140 Control unit 1 42 Reference sensor 143 Image density sensor 150 Paper storage unit 151 Paper supply roll 152 Transport roll 153 Transport guide 155 Transport belt 156 Fixing entrance guide K Paper N nip

Claims (16)

An image carrier,
Charging means for charging the surface of the image holding member,
Electrostatic image forming means for forming an electrostatic image on the surface of the charged image carrier,
A developer containing a toner having toner particles containing a release agent having a melting temperature of 60 ° C. or more and 100 ° C. or less is contained, and the developer is used to develop an electrostatic charge image formed on the surface of the image holding member. Developing means for forming an image;
Transfer means for transferring the toner image to a first surface of a recording medium;
A belt member for bringing an outer peripheral surface into contact with the first surface of the recording medium; and a rotating body pair having a rotating body that forms a contact area by contacting the outer peripheral surface of the belt member, wherein the toner image is transferred. Fixing means for inserting and heating the recording medium through the contact area, and fixing the toner image on the first surface;
On the upstream side of the contact area in the recording medium transport direction and on the first surface side of the recording medium, an air supply inlet provided around the contact area, and on the downstream side of the contact area in the recording medium transport direction and the On the first surface side of the recording medium, there is provided an air supply outlet provided around a conveyance path of the recording medium, and the air supply inlet and the air supply outlet are connected through an inner peripheral side of the belt member. An air supply pipe that exhausts gas that has entered from the air supply inlet toward the recording medium from the air supply outlet,
An image forming apparatus comprising:   The image forming apparatus according to claim 1, wherein a melting temperature of the release agent in the toner particles is 60 ° C. or more and 90 ° C. or less.   The image forming apparatus according to claim 1, wherein the release agent in the toner particles is paraffin wax.   The image forming apparatus according to claim 1, wherein the toner particles include a crystalline resin.   The image forming apparatus according to claim 4, wherein the content of the crystalline resin is 3% by mass or more and 20% by mass or less based on the mass of the toner particles.   The image forming apparatus according to claim 5, wherein the content of the crystalline resin is 5% by mass or more and 15% by mass or less based on the mass of the toner particles.   The image forming apparatus according to claim 1, wherein a toluene-insoluble content of the toner particles is 25% by mass or more and 40% by mass or less.   The image forming apparatus according to claim 1, wherein the shape factor SF1 of the toner particles is 140 or more.   The image forming apparatus according to claim 1, wherein the rotating body is a roll member.   The image forming apparatus according to claim 1, wherein the belt member is a belt member having a polyimide resin layer.   The image forming apparatus according to claim 1, wherein the belt member is a heating belt member that heats the toner image.   12. The image forming apparatus according to claim 11, further comprising: a heating member that contacts and heats the belt member on an inner peripheral surface side of the belt member, and wherein the air supply pipe is disposed above the heating member in a gravity direction. apparatus.   The image forming apparatus according to claim 1, wherein a maximum diameter of a portion of the air supply pipe passing through an inner peripheral side of the belt member is 2 mm or more and 10 mm or less.   14. The image forming apparatus according to claim 1, wherein a fixing set temperature in the rotating body pair is 100 ° C. or more and 200 ° C. or less.   The image forming apparatus according to claim 14, wherein a set fixing temperature of the pair of rotating members is 120 ° C. or more and 200 ° C. or less.   15. The difference [T1-T2] between the fixing set temperature [T1] in the rotating body pair and the melting temperature [T2] of the release agent in the toner particles is 40 ° C. or more and 120 ° C. or less. The image forming apparatus according to claim 15.