JP2015129797A - Image-fixing tubular body, fixing apparatus, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image-fixing tubular body configured to maintain slidability on an inner peripheral surface and to prevent separation at an interface on an outer periphery of a substrate.SOLUTION: An image-fixing tubular body 110A includes: a substrate 112A containing resin and a fluorine resin particle 116, which exists at a higher presence ratio (area ratio) on a surface of an inner periphery than on a surface of an outer periphery; and an elastic layer 114 formed on the side of the outer periphery of substrate 112A.

Description

  The present invention relates to an image fixing tubular body, a fixing device, and an image forming apparatus.

  As the image fixing device provided in the image forming apparatus, for example, the following are known.

  In Patent Document 1, a heat-resistant fixing film is brought into close contact with a visible image holding surface of a recording material on which an unfixed visible image is formed and held by a heat-meltable developer, and the target film is interposed through the fixing film. A fixing device for fixing a visible image on a recording material by applying heat to the recording material to heat and melt the visible image and then separating the fixing film and the recording material. A fixing device is disclosed in which a material mainly containing fluorinated polyimide is used.

Japanese Patent Laid-Open No. 9-274402

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image fixing tubular body that can maintain the slidability on the inner peripheral surface side and suppress the peeling at the interface on the outer peripheral surface side of the substrate.

The above problems are solved by the present invention described below. That is,
The invention according to claim 1
A substrate containing a resin and fluororesin particles, wherein the presence rate (area ratio) of the fluororesin particles on the inner peripheral surface side is higher than the presence rate (area ratio) of the fluororesin particles on the outer peripheral surface side When,
An elastic layer on the outer peripheral surface side of the substrate;
An image fixing tubular body having

The invention according to claim 2
The substrate has a multilayer structure having at least an innermost peripheral layer and an outermost peripheral layer, and the concentration of the fluororesin particles in the innermost peripheral layer is higher than the concentration of the fluororesin particles in the outermost peripheral layer. The tubular body for image fixing described in 1.

The invention according to claim 3
2. The tubular body for image fixing according to claim 1, wherein the substrate has a single layer structure, and the fluororesin particles are unevenly distributed on the inner peripheral surface side in the substrate having the single layer structure.

The invention according to claim 4
The image fixing tubular body according to any one of claims 1 to 3, wherein the resin is a resin that does not contain a fluorine atom in its structure.

The invention according to claim 5
A fixing device comprising the image fixing tubular body according to any one of claims 1 to 4.

The invention according to claim 6
An image carrier,
Charging means for charging the surface of the image carrier;
Latent image forming means for forming a latent image on the surface of the charged image carrier;
Developing means for developing the latent image with toner to form a toner image;
Transfer means for transferring the toner image to a recording medium;
Fixing means that is a fixing device according to claim 5, wherein the toner image is fixed on a recording medium;
An image forming apparatus including at least

  According to the first aspect of the present invention, compared to the case where the abundance ratio of the fluororesin particles on the inner peripheral surface side is equal to the abundance ratio of the fluororesin particles on the outer peripheral surface side, the slidability on the inner peripheral surface side. An image fixing tubular body that can suppress peeling at the interface on the outer peripheral surface side of the substrate is obtained.

  According to the invention of claim 2, the substrate has a multi-layer structure having at least the innermost peripheral layer and the outermost peripheral layer, and the concentration of the fluororesin particles in the innermost peripheral layer is the concentration of the fluororesin particles in the outermost peripheral layer. With the higher configuration, it is possible to obtain an image fixing tubular body that can maintain the slidability on the inner peripheral surface side and can suppress peeling at the interface on the outer peripheral surface side of the substrate.

  According to the invention of claim 3, the structure is such that the substrate has a single-layer structure and the fluororesin particles are unevenly distributed on the inner peripheral surface side in the single-layer structure substrate. An image fixing tubular body capable of maintaining the slidability and suppressing the peeling at the interface on the outer peripheral surface side of the substrate is obtained.

  According to the fourth aspect of the present invention, an image fixing tubular body that can hold the lubricant better on the inner peripheral surface side than the case where the resin is a resin containing a fluorine atom in the structure is obtained.

  According to the fifth aspect of the present invention, the tubular body is provided as compared with the case where the image fixing tubular body is provided in which the abundance ratio of the fluororesin particles on the inner peripheral surface side is equal to the abundance ratio of the fluororesin particles on the outer peripheral surface side. A fixing device that can maintain the slidability on the inner peripheral surface side and suppress the peeling of the tubular body is obtained.

  According to the invention of claim 6, the tubular body is provided as compared with the case where the tubular body for image fixing is provided in which the abundance ratio of the fluororesin particles on the inner peripheral surface side is equal to the abundance ratio of the fluororesin particles on the outer peripheral surface side. Thus, an image forming apparatus that can maintain the slidability on the inner peripheral surface side and suppress the peeling of the tubular body is obtained.

It is an expanded sectional view of the inner peripheral surface side surface of the substrate of the tubular body for image fixing according to the present embodiment. It is a schematic perspective view which shows an example of the tubular body for image fixing concerning this embodiment. It is AA sectional drawing of FIG. It is sectional drawing which shows another example of the tubular body for image fixing which concerns on this embodiment. It is a schematic diagram (figure seen from the side) for demonstrating the spiral coating method at the time of forming the base | substrate in this embodiment. It is a schematic diagram (figure seen from the front) for demonstrating the spiral coating method at the time of forming the base | substrate in this embodiment. 1 is a schematic configuration diagram illustrating an example of a fixing device according to a first embodiment. It is a schematic block diagram which shows an example of the fixing device which concerns on 2nd Embodiment. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an exemplary embodiment.

Hereinafter, embodiments of an image fixing tubular body, a fixing device, and an image forming apparatus of the present invention will be described in detail.
In addition, when it demonstrates using drawing, the same code | symbol is provided to the member which has substantially the same function, and the overlapping description may be abbreviate | omitted suitably.

≪Tube for image fixing≫
The tubular body for image fixing according to the present embodiment (hereinafter also simply referred to as “tubular body”) includes a substrate containing resin and fluororesin particles, and an elastic layer on the outer peripheral surface side of the substrate.
The abundance (area ratio) of the fluororesin particles on the inner peripheral surface side surface of the base is higher than the abundance (area ratio) of the fluororesin particles on the outer peripheral surface side.

  Conventionally, in a tubular body having at least a base body and an elastic layer on the outer peripheral surface side of the base body, fluororesin particles have been added to the base body from the viewpoint of obtaining slidability on the inner peripheral surface side of the tubular body To be done. However, when the fluororesin particles are present uniformly throughout the substrate, the contact surface with the elastic layer provided on the outer peripheral surface side of the substrate (or when another layer is interposed between the substrate and the elastic layer) In this case, good adhesion was not obtained at the contact surface with the other layer on the outer peripheral surface side of the substrate, and peeling occurred at the interface on the outer peripheral surface side of the substrate.

In contrast, in the present embodiment, the above-described configuration effectively suppresses peeling at the interface on the outer peripheral surface side of the substrate while maintaining the slidability on the inner peripheral surface side of the tubular body. obtain.
This is because slidability is expressed by the function of the exposed fluororesin particles on the inner peripheral surface side surface of the substrate, while the abundance of the fluororesin particles is reduced on the outer peripheral surface surface of the substrate. This is probably because the inhibition of adhesion by the exposed fluororesin particles is suppressed.

Further, as shown in the enlarged view of the inner peripheral surface side surface of the base body in FIG. 1, the exposed fluororesin particles 116 exist on the inner peripheral surface side surface 112N of the base body 112. On the other hand, the exposed fluororesin particles Since a part of 116 is detached from the base 112 without being held, a hemispherical recess 120 is formed on the inner surface 112N of the base 112.
Since the image fixing tubular body according to this embodiment is used in such a manner that it slides with a member that supports the image fixing tubular body from the inner surface side, a lubricant is applied to the sliding surface with the supporting member. May be used. At this time, the lubricant is held by the recess 120 due to the presence of the hemispherical recess 120 on the surface 112N on the inner peripheral surface side of the substrate 112 of the image fixing tubular body. improves.

-Calculation method of abundance ratio of fluororesin particles-
In the present embodiment, the abundance ratio of the fluororesin particles on the inner peripheral surface side or outer peripheral surface side surface of the substrate is represented by the area of the exposed fluororesin particles occupying per surface area.
The measurement of the abundance of the fluororesin particles on the inner peripheral surface side and the outer peripheral surface side of the substrate, that is, the measurement of the area of the exposed fluororesin particles per area is performed by the following method.

  That is, it is performed by photographing the surface to be measured, performing image processing (binarization processing), and calculating the area of the exposed fluororesin particles. Note that SEM (manufactured by JEOL Ltd., trade name: JSM-6700F / JED-2300F) is used for photographing the surface. In addition, the product name: Image-ProPlus manufactured by Media Cybetics is used as the image processing software, and the image processing is performed by binarizing a monochrome image and distinguishing the measurement target in the image from the non-measurement target of the image. I do.

The abundance ratio (area ratio) of the fluororesin particles on the inner peripheral surface of the substrate is preferably 10% or more and 95% or less, and more preferably 30% or more and 85% or less. More preferably, it is 50% or more and 80% or less.
On the other hand, the value of the abundance (area ratio) of the fluororesin particles on the surface on the outer peripheral surface side of the substrate is preferably 0% or more and 10% or less, more preferably 0% or more and 5% or less, More preferably, it is 0%.

Hereinafter, the tubular body according to the present embodiment will be described with reference to the drawings.
FIG. 2 is a schematic perspective view showing an example of a tubular body for image fixing according to the present embodiment. FIG. 3 is a cross-sectional view taken along the line AA of FIG.
A tubular body 110A shown in FIGS. 2 and 3 is an endless belt member, and is provided on a base 112A, an elastic layer 114 provided on the outer peripheral surface of the base 112A, and an outer peripheral surface of the elastic layer 114. It is a laminate composed of three layers, the surface layer 118.

  The substrate 112A in FIG. 3 is a substrate having a single-layer structure, and in the substrate 112A having a single-layer structure, the abundance of the fluororesin particles on the surface on the inner peripheral surface side is the amount of the fluororesin particles on the surface on the outer peripheral surface side. It is adjusted higher than the presence rate. For example, in the base 112A shown in FIG. 3, since the fluororesin particles 116 are unevenly distributed on the inner peripheral surface side in the base 112A, the presence rate of the fluororesin particles on the inner peripheral surface is higher. The configuration with is realized.

  In the present embodiment, the substrate may have a multi-layer structure. A tubular body 110B shown in FIG. 4 is an endless belt member, and includes a base 112B, an elastic layer 114 provided on the outer peripheral surface of the base 112B, and a surface layer 118 provided on the outer peripheral surface of the elastic layer 114. And the base body 112B is composed of two layers of the innermost peripheral layer 1121 and the outermost peripheral layer 1122.

  In the substrate 112B having a multi-layer structure in FIG. 4 as well, the abundance ratio of the fluororesin particles on the inner peripheral surface as a whole is adjusted to be higher than the abundance ratio of the fluororesin particles on the outer peripheral surface. Yes. For example, in the base body 112 </ b> B shown in FIG. 4, the concentration of the fluororesin particles 116 in the innermost peripheral layer 1121 is adjusted to be higher than the concentration of the fluororesin particles 116 in the outermost peripheral layer 1122. A configuration in which the abundance ratio of the fluororesin particles is higher is realized. Although FIG. 4 shows a mode in which the outermost peripheral layer 1122 of the base body 112B does not contain fluororesin particles, the present invention is not limited to this.

  Note that the tubular body 110A (or 110B) according to the present embodiment is not limited to the above-described layer configuration, and may have a configuration without the surface layer 118. For the above-described layer configuration, for example, A layer structure in which a metal layer, a protective layer thereof, or the like is interposed between the base body 112A (or 112B) and the elastic layer 114 may be employed. Furthermore, each layer may be formed through an adhesive layer.

  Hereinafter, each layer which comprises the tubular body which concerns on this embodiment is demonstrated. The reference numerals are omitted.

[Substrate]
The substrate is not particularly limited as long as it satisfies the configuration that the abundance ratio of the fluororesin particles on the surface on the inner peripheral surface side is higher than the abundance ratio of the fluororesin particles on the surface on the outer peripheral surface side. A substrate having a layer structure may be used, and a substrate having a multilayer structure having at least an innermost peripheral layer and an outermost peripheral layer may be used.

-First embodiment / Substrate having a multi-layer structure-
In the case of a substrate having a multi-layer structure, the abundance of the fluororesin particles on the inner peripheral surface side surface of the innermost peripheral layer is higher than the abundance of the fluororesin particles on the outer peripheral surface side surface of the outermost peripheral layer.
Although not particularly limited, for example, as shown in FIG. 4, the concentration of the fluororesin particles 116 in the innermost peripheral layer 1121 is adjusted to be higher than the concentration of the fluororesin particles 116 in the outermost peripheral layer 1122. Thus, a configuration in which the abundance ratio of the fluororesin particles on the inner peripheral surface side surface is higher is realized. In addition, it is more preferable that an outermost peripheral layer is a structure which does not contain a fluororesin particle.

  Here, the substrate having a multi-layer structure will be described in detail taking as an example the case of a two-layer structure.

Both the innermost peripheral layer and the outermost peripheral layer of the substrate contain a resin.
Examples of the resin material used for the substrate include polyimide, polyamide, polyamideimide, polyphenylene sulfide, polyether ether ketone, and polybenzimidazole. Among these, polyimide and polyamideimide are preferable.

The resins listed above may further be resins containing fluorine atoms in the structure (for example, fluorine-modified resins). However, the resin used for the innermost peripheral layer is more preferably a resin that does not contain a fluorine atom in the structure.
Since the resin used in the innermost peripheral layer containing the fluororesin particles does not contain fluorine atoms in the structure, the exposed fluororesin particles on the inner peripheral surface side are more efficiently detached from the substrate. A hemispherical recess is easily formed on the inner peripheral surface of the substrate. As a result, the lubricant is better retained on the inner peripheral surface side of the substrate.
Although this mechanism is not necessarily clear, a resin that does not contain a fluorine atom in the structure has a lower strength to hold the fluororesin particles exposed on the surface than a resin that contains a fluorine atom in the structure. This is probably because the fluororesin particles are effectively detached.

  On the other hand, the resin used for the outermost peripheral layer is more preferably a resin that does not contain a fluorine atom in the structure.

  In addition, resin contained in each of the innermost circumferential layer and the outermost circumferential layer may be the same or different. Further, when the substrate has a structure of three or more layers with another layer interposed between the innermost layer and the outermost layer, the innermost layer and the outermost layer are also included in the resin contained in the other layer. May be the same or different.

  In a multi-layer structure substrate, at least the innermost peripheral layer contains fluororesin particles. Further, the outermost peripheral layer may contain fluororesin particles, and when the substrate has a structure of three or more layers, the outermost peripheral layer and other layers other than the outermost outer peripheral layer may also contain fluororesin particles.

  Examples of the fluororesin particles used for the substrate include tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-perfluoromethyl vinyl ether copolymer (MFA), and tetrafluoroethylene-perfluoroethyl vinyl ether copolymer. Polymer (EFA), polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), polyethylene-tetrafluoroethylene (ETFE), polyvinylidene fluoride (PVDF), polychlorotrifluoride ethylene ( PCTFE) and vinyl fluoride (PVF). Among these, polytetrafluoroethylene (PTFE) and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) are preferable.

From the viewpoint of ease of production, it is preferable that the fluororesin particles in the innermost layer and the outermost layer are present uniformly.
The concentration of the fluororesin particles in the innermost peripheral layer is preferably adjusted so that the abundance of the fluororesin particles on the inner peripheral surface side surface of the substrate is in the above-described range. Moreover, it is preferable that the density | concentration of the fluororesin particle in an outermost periphery layer is adjusted so that the abundance rate of the fluororesin particle in the outer peripheral surface side surface of a base | substrate may become the above-mentioned range.

  Further, the substrate may contain a filler such as metal oxide, graphite, and heat transfer ceramics.

  An example of the manufacturing method will be described as follows for a method of manufacturing a substrate having a multi-layer structure, taking a substrate having a two-layer structure as an example. However, the method for producing a substrate having a multi-layer structure is not limited to the following method.

First, the coating solution for the innermost circumferential layer containing the resin and the fluororesin particles in the solvent, and whether the solvent contains the resin and the fluororesin particles having a lower concentration than the coating solution for the innermost circumferential layer. Alternatively, a coating solution for the outermost peripheral layer containing no fluororesin particles is prepared.
Next, after applying and drying the coating solution for the innermost layer on the outer surface of the cylindrical mold (first coating and drying step), the coating solution for the outermost layer is further applied to the outer peripheral surface side. A substrate having a two-layer structure is obtained by drying (second coating and drying step).

  Further, if necessary, a baking treatment may be performed after the first coating / drying step and before the second coating / drying step or after the second coating / drying step. That is, when the substrate is a layer made of polyimide resin, for example, it may be formed by using polyamic acid, which is a precursor of polyimide resin, and baking it. Such firing may be performed before the elastic layer described later is formed, or may be performed in the course of drying the elastic layer.

Second Embodiment / Substrate with Single Layer Structure
In the case of a substrate having a single layer structure, the abundance ratio of the fluororesin particles on the inner peripheral surface side surface is higher than the abundance ratio of the fluororesin particles on the outer peripheral surface side surface.
Although not particularly limited, for example, as shown in FIG. 3, the fluorine resin particles 116 are unevenly distributed on the inner peripheral surface side in the substrate 112A having a single-layer structure, so that fluorine on the inner peripheral surface side surface can be obtained. A configuration in which the abundance ratio of the resin particles is higher is realized.

  As other members such as resin, fluororesin particles, filler, etc. contained in the single-layer substrate, the various members described in the case of the aforementioned multi-layer structure are used as they are. In addition, as resin, it is more preferable that it is resin which does not contain a fluorine atom in a structure.

Examples of a method for producing a substrate having a single layer structure include the following methods.
(Manufacturing method (1))
First, a coating solution for a substrate containing a resin and fluororesin particles in a solvent is prepared. Next, the coating liquid is applied to the inner surface of a centrifugal mold, and a base belt in which the fluororesin particles are biased to the outer peripheral surface side is prepared by centrifugal molding. After cutting the base belt into a sheet shape, the end portions are bonded to each other so that the surface of the sheet on which the fluororesin particles are unevenly present becomes the inner peripheral surface side. Such a single layer substrate is produced.
The drying step and the firing step performed when necessary are performed by the same method as that for manufacturing the above-described two-layer substrate.

  In the production method (1), the specific gravity of the contained fluororesin particles is required to be heavier than that of the resin.

(Manufacturing method (2))
First, a coating solution for a substrate containing a resin and fluororesin particles having a lighter specific gravity than the resin in a solvent is prepared. Next, the coating liquid is applied to the inner surface of the mold for centrifugal molding, and the annular body is formed by centrifugal molding, so that the fluororesin particles are biased to the inner peripheral surface side, and the single layer according to this embodiment The substrate is manufactured.

  Examples of the fluororesin particles that can be used in the above method include hollow fluororesin particles. The material of the hollow fluororesin particles is not particularly limited, and the above-mentioned materials are used as they are.

(Manufacturing method (3))
First, is the coating liquid for the inner peripheral surface side containing the resin and the fluororesin particles in the solvent, and whether the solvent contains the fluororesin particles having a lower concentration than the coating liquid for the inner peripheral surface side? Alternatively, a coating solution for the outer peripheral surface side that does not contain fluorine resin particles is prepared.
Next, after applying the coating liquid for the inner peripheral surface side to the outer surface of the cylindrical mold and then drying to such an extent that it is not dried or is kept in a liquid state even when drying is performed. Then, a coating solution for the outer peripheral surface is further applied onto the coating solution for the inner peripheral surface while maintaining the liquid state. Next, by drying, a single-layer substrate according to the present embodiment in which the interface between the inner peripheral surface side and the outer peripheral surface side does not exist and the fluororesin particles are biased to the inner peripheral surface side is manufactured.

(Manufacturing method (4))
First, a coating solution for a substrate is prepared, which contains a resin and fluororesin particles in a solvent, and the fluororesin particles are aggregated by reducing the dispersibility of the fluororesin particles.
Next, the above coating solution is applied to the outer surface of the cylindrical mold and dried, so that the aggregated fluororesin particles do not collect on the surface side but exist on the contact surface side with the mold, that is, on the inner peripheral surface side. A single layer substrate according to the present embodiment is manufactured.

  If necessary, a baking treatment may be performed after coating and drying of the coating solution. Such firing may be performed before the elastic layer described later is formed, or may be performed in the course of drying the elastic layer.

Here, as a control method for reducing the dispersibility of the fluororesin particles in the dispersion, first, a method using a resin that does not contain a fluorine atom in the structure is used as the resin. By using a resin that does not contain a fluorine atom, the dispersibility of the fluororesin particles is lowered and aggregation tends to occur.
In addition, as a control method for reducing the dispersibility of the fluororesin particles in the dispersion liquid, a micelle such as a rod-like micelle or a bilayer membrane is added by adding a surfactant in an amount exceeding the critical micelle concentration. Examples thereof include a method of forming a higher order structure such as a structure or a hexagonal phase. For example, when MegaFac, which is a DIC surfactant, is used, for example, aggregation is likely to occur by adding 20% by mass or more to PTFE particles.

-Description of application | coating and drying process Here, the coating method and drying method used when manufacturing the base | substrate of a multilayer structure or a single layer structure are demonstrated. In addition, it demonstrates taking the case of using the polyamic acid which is a polyimide precursor as an example.

  There are no particular restrictions on the method of applying the coating liquid used to form the substrate to the outer surface of the cylindrical mold or the inner surface of the mold of the centrifugal molding machine. For example, the mold is immersed in the coating liquid, There are a method of applying to the outer peripheral surface or the inner peripheral surface, and a method of applying to the outer peripheral surface or the inner peripheral surface by “spiral coating method” or “die method coating method” while rotating the mold with the shaft horizontal. Can be mentioned.

After coating, the coating film of the coating liquid for substrate formation is dried. The drying conditions are, for example, 10 to 60 minutes at a temperature of 80 ° C. to 200 ° C., and the higher the temperature, the shorter the heating time.
It is also effective to apply hot air during heating.
During heating, the temperature may be increased stepwise or increased without changing the speed.
Furthermore, it is preferable to rotate the mold at 5 rpm or more and 60 rpm or less with the axial direction of the mold horizontal when heating. The mold may be vertical after drying.

After drying, the coating film is subjected to imidization treatment (firing). As imidization treatment (firing) conditions, for example, an imidization reaction occurs by heating at 250 ° C. or higher and 450 ° C. or lower (desirably 300 ° C. or higher and 350 ° C. or lower) for 20 minutes or longer and 60 minutes or shorter. A film is formed.
In the heating reaction, before reaching the final temperature of heating, it is preferable to heat by gradually increasing the temperature stepwise or at a constant rate.

  Here, as an example of the coating method in forming the substrate in the present embodiment, a spiral coating method using the apparatus shown in FIGS. 5 and 6 will be described.

FIG. 5 and FIG. 6 are schematic views for explaining a spiral coating method when forming a substrate in the present embodiment.
As shown in FIGS. 5 and 6, an apparatus 200 that performs spiral coating (hereinafter referred to as “coating apparatus 200”) includes a cylindrical core body 210. The cylindrical core 210 has a release treatment layer 211 on the outer peripheral surface. The cylindrical core body 210 can rotate in the circumferential direction of the arrow A.

The coating apparatus 200 includes a storage unit 222 that stores the substrate-forming coating liquid 112E, a supply pipe 224 that is connected to the storage part 222, a pump 226 that is connected to the supply pipe 224, a nozzle 228 that is connected to the pump 226, The application part (application | coating means) 220 provided with is provided.
The coating unit 220 coats the coating liquid 112E for substrate formation on the outer surface of the core body 210 rotating in the circumferential direction indicated by the arrow A.

A method of applying the coating liquid 112E for substrate formation by the application unit 220 will be described more specifically.
According to the coating unit 220, the outer surface of the core body 210 in which the coating liquid 112E for substrate formation stored in the storage unit 222 is rotated in the direction of arrow A by the pump 226 through the supply pipe 224 and the nozzle 228. To be supplied.
The coating unit 220 moves relative to the core body 210 from one end side in the longitudinal direction (axial direction) of the core body 210 toward the other end side (in the direction of arrow B in FIG. 5), while applying the coating liquid for forming the substrate. By supplying 112E from the nozzle 228, the coating liquid 112E for forming the substrate is spirally applied to the outer surface of the core body 210.
In addition, in the coating apparatus 200, the aspect which moves the application part 220 with respect to the core 210 may be sufficient, the aspect which moves the core 210 with respect to the application part 220 may be sufficient, and the core 210 may be sufficient as it. It is also possible to move both the coating unit 220 and the coating unit 220.

The coating apparatus 200 includes a smoothing unit including a roll 230 and a drive unit (not shown) that rotates and moves the roll 230 in addition to the coating unit 220 described above.
This roll 230 is installed toward one end side (the spiral coating start point side, the upstream side in the direction of arrow B in FIG. 5) in the longitudinal direction (axial direction) of the core body 210, and the outer periphery of the roll 230 is the core. The substrate-forming coating solution 112E is spread and smoothed by rotating while being in contact with the substrate-forming coating solution 112E applied on the body 210.
The roll 230 rotates and contacts the coating liquid 112E for forming the substrate while moving from one end side to the other end side in the longitudinal direction of the core body 210 with respect to the core body 210 (in the arrow B direction in FIG. 5). By doing so, the coating film 112T is formed on the core body 210.

  The size (diameter, width), pressing force, rotation speed, and the like of the roll 230 may be determined according to the application pitch, movement speed, application amount, viscosity, and the like of the application liquid.

  The roll 230 may be a rubber roll using silicon rubber (silicone rubber), urethane rubber, nitrile / butadiene rubber, or fluorine rubber, or a metal roll such as SUS, SK material, or aluminum.

  The total thickness of the substrate is, for example, in the range of 20 μm to 200 μm, preferably 30 μm to 150 μm, more preferably 40 μm to 130 μm.

[Elastic layer]
The elastic layer in the present embodiment includes an elastic material, and may further include a filler.

The elastic material constituting the elastic layer is preferably a heat resistant elastic material.
Examples of the heat resistant elastic material include silicone rubber and fluoro rubber.
Examples of the silicone rubber include RTV silicone rubber, HTV silicone rubber, and liquid silicone rubber. Specifically, polydimethyl silicone rubber (MQ), methyl vinyl silicone rubber (VMQ), methyl phenyl silicone rubber (PMQ). ), Fluorosilicone rubber (FVMQ) and the like.
Examples of the fluororubber include vinylidene fluoride rubber, tetrafluoroethylene / propylene rubber, tetrafluoroethylene / perfluoromethyl vinyl ether rubber, phosphazene rubber, and fluoropolyether.
Note that “heat resistance” means a characteristic that does not melt or decompose even when the temperature rises (for example, the fixing temperature) of the fixing device. The same applies hereinafter.

The filler contained in the elastic layer is preferably an inorganic material having a smaller thermal expansion than the organic material, and specifically, carbide (eg, carbon black, carbon fiber, carbon nanotube, etc.), titanium oxide, silica Well-known filling of silicon carbide, talc, mica, kaolin, calcium carbonate, calcium silicate, magnesium oxide, graphite, silicon nitride, boron nitride, iron oxide (Bengara), cerium oxide, aluminum oxide, magnesium carbonate, metal silicon, etc. Agents.
Among these, Bengala, alumina, and silica are preferably used from the viewpoint of reinforcing effect, heat deterioration resistance, cost, and availability.

  The content of the filler is preferably 20% by mass to 80% by mass with respect to the elastic layer, desirably 30% by mass to 70% by mass, and more desirably 40% by mass to 60% by mass. % Or less.

Various additives may be blended in the elastic layer.
Examples of additives include softeners (paraffins, etc.), processing aids (stearic acid, etc.), anti-aging agents (amines, etc.), vulcanizing agents (sulfur, metal oxides, peroxides, etc.), etc. Can be mentioned.

  The thickness of the elastic layer is, for example, preferably from 30 μm to 600 μm, and preferably from 100 μm to 500 μm.

[Surface layer]
The surface layer includes, for example, a heat resistant release material.
Examples of the heat-resistant release material include fluororubber, fluororesin, silicone resin, and polyimide resin.
Among these, a fluororesin is preferable as the heat-resistant release material.
Specific examples of the fluororesin include, for example, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), polyethylene / tetra Examples include fluoroethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), polychloroethylene trifluoride (PCTFE), and vinyl fluoride (PVF).

  In addition, the surface layer may include various known additives.

  The thickness of the surface layer is, for example, preferably from 5 μm to 50 μm, and desirably from 10 μm to 40 μm.

[Adhesive layer, metal layer, other layers]
The tubular body according to the present embodiment may have an adhesive layer between the base material and the elastic layer, or between the elastic layer and the surface layer.
The adhesive layer should just be formed with the adhesive which has heat resistance, and a well-known thing is applied.
Further, the tubular body according to the present embodiment may be provided with a metal layer (heat generation layer) that generates heat by electromagnetic induction between the base and the elastic layer.

  As described above, the tubular body according to the present embodiment has been described as being formed of a laminated body of a base body, an elastic layer, and a surface layer. However, depending on the material of the elastic layer, a laminated body having no surface layer may be used. It may be a laminate including other layers.

[Use]
The tubular body according to the present embodiment is applied to, for example, both a heating belt and a pressure belt during image fixing. The heating belt may be either a heating belt that is heated by an electromagnetic induction method or a heating belt that is heated from an external heat source.
However, when the tubular body according to this embodiment is applied to a heating belt that is heated by an electromagnetic induction method, a metal layer (heat generation layer) that generates heat by electromagnetic induction may be provided between the base and the elastic layer.

≪Fixing device≫
The fixing device according to the present embodiment includes the tubular body according to the present embodiment described above.
The fixing device according to the present embodiment has various configurations, for example, a configuration including a first rotating body and a second rotating body arranged in contact with the outer surface of the first rotating body. And the tubular body which concerns on this embodiment is applied as at least one of a 1st rotary body and a 2nd rotary body.

Hereinafter, a fixing device including a heating belt and a pressure roll will be described as first and second embodiments. In the first and second embodiments, the tubular body according to this embodiment can be applied to both the heating belt and the pressure roll.
The fixing device according to this embodiment is not limited to the first and second embodiments, and may be a fixing device including a heating roll or a heating belt and a pressure belt. The tubular body according to the present embodiment can be applied to any of a heating roll, a heating belt, and a pressure belt.
The fixing device according to the present embodiment is not limited to the first and second embodiments, and may be an electromagnetic induction heating type fixing device.

[First Embodiment of Fixing Device]
The fixing device according to the first embodiment will be described. FIG. 7 is a schematic diagram illustrating an example of a fixing device according to the first embodiment.

As shown in FIG. 7, the fixing device 60 according to the first embodiment includes, for example, a heating roll 61 (an example of a first rotating body) that is rotationally driven, a pressure belt 62 (an example of a second rotating body), A pressing pad 64 (an example of a pressing member) that presses the heating roll 61 via the pressure belt 62 is provided.
In addition, the press pad 64 should just pressurize the pressurization belt 62 and the heating roll 61 relatively, for example. Therefore, the pressure belt 62 side may be pressed by the heating roll 61, and the heating roll 61 side may be pressed by the heating roll 61.

  Inside the heating roll 61, a halogen lamp 66 (an example of a heating means) is disposed. The heating means is not limited to the halogen lamp, and other heat generating members that generate heat may be used.

  On the other hand, for example, a temperature sensitive element 69 is disposed on the surface of the heating roll 61 in contact therewith. The lighting of the halogen lamp 66 is controlled based on the temperature measurement value by the temperature sensitive element 69, and the target temperature of the heating roll 61 is maintained at a target set temperature (for example, 150 ° C. or higher and 230 ° C. or lower).

  The pressure belt 62 is rotatably supported by, for example, a pressing pad 64 and a belt traveling guide 63 disposed inside. And it is pressed against the heating roll 61 by the pressing pad 64 in the sandwiching area N (nip part).

For example, the pressing pad 64 is disposed inside the pressure belt 62 in a state of being pressed against the heating roll 61 via the pressure belt 62, and forms a sandwiching region N with the heating roll 61. Yes.
For example, the pressing pad 64 is provided with a front clamping member 64a for securing a wide clamping area N on the entrance side of the clamping area N, and a peeling clamping member 64b for distorting the heating roll 61. Is arranged on the exit side of the sandwiching region N.

In order to reduce the sliding resistance between the inner peripheral surface of the pressure belt 62 and the pressing pad 64, for example, a sheet-like sliding on the surface of the front sandwiching member 64a and the peeling sandwiching member 64b in contact with the pressure belt 62 A member 68 is provided. The pressing pad 64 and the sliding member 68 are held by a metal holding member 65.
The sliding member 68 is provided, for example, so that its sliding surface is in contact with the inner peripheral surface of the pressure belt 62, and is involved in holding and supplying oil existing between the sliding member 68 and the pressure belt 62. .

  For example, a belt traveling guide 63 is attached to the holding member 65 so that the pressure belt 62 rotates. The belt running guide 63 may be provided with a lubricant supply device 67 that is a means for supplying a lubricant (oil) to the inner peripheral surface of the pressure belt 62.

  For example, the heating roll 61 is rotated in the arrow S direction by a drive motor (not shown), and the pressure belt 62 is rotated in the arrow R direction opposite to the rotation direction of the heating roll 61 following the rotation. That is, for example, while the heating roll 61 rotates in the clockwise direction in FIG. 7, the pressure belt 62 rotates in the counterclockwise direction.

  Then, the sheet K (an example of a recording medium) having an unfixed toner image is guided by, for example, the fixing inlet guide 56 and conveyed to the sandwiching area N. When the paper K passes through the sandwiching area N, the toner image on the paper K is fixed by pressure and heat acting on the sandwiching area N.

  In the fixing device 60 according to the first embodiment, for example, the concave sandwiched front sandwiching member 64a that follows the outer peripheral surface of the heating roll 61 has a wider sandwiched region N as compared to the configuration without the front sandwiching member 64a. Secured.

  Further, in the fixing device 60 according to the first embodiment, for example, by disposing the peeling sandwiching member 64 b so as to protrude from the outer peripheral surface of the heating roll 61, the heating roll 61 is distorted in the exit region of the sandwiching region N. Is configured to be locally large.

  If the peeling and clamping member 64b is arranged in this way, for example, the sheet K after being fixed passes through the locally formed distortion when passing through the peeling and clamping area. Is easy to peel from the heating roll 61.

  As an auxiliary means for peeling, for example, a peeling member 70 is disposed on the downstream side of the sandwiching area N of the heating roll 61. For example, the peeling member 70 is held by the holding member 72 in a state in which the peeling claw 71 is close to the heating roll 61 in a direction (counter direction) opposite to the rotation direction of the heating roll 61.

[Second Embodiment of Fixing Device]
A fixing device according to the second embodiment will be described. FIG. 8 is a schematic diagram illustrating an example of a fixing device according to the second embodiment.

  As shown in FIG. 8, the fixing device 150 according to the second embodiment is arranged to be pressed against a fixing belt module including a heating belt 151 (an example of a first rotating body) and the heating belt 151 (fixing belt module), for example. And a pressure roll 156 (an example of a second rotating body). For example, a sandwiching region (nip portion) where the heating belt 151 (fixing belt module) and the pressure roll 156 come into contact is formed. In the sandwiching area, the paper (recording medium) is pressurized and heated to fix the toner image.

  The fixing belt module includes, for example, an endless heating belt 151, a fixing pad 153 around which the heating belt 151 is wound on the pressure roll 156 side, and presses the heating belt 151 from the inner peripheral surface thereof to the pressure roll 156 side, Support rolls 152 and 154 that support the heating belt 151 from the inside at a position different from the fixed pad 153 are provided.

  In the fixing belt module, for example, the fixed pad 153 is provided so as to be in contact with the inner peripheral surface of the heating belt 151, and a lubricant is applied to a sliding portion between the heating belt 151 and the fixed pad 153.

The support rolls 152 and 154 are, for example, cylindrical rolls made of aluminum. Further, a halogen heater 157 (an example of a heating unit) is disposed inside the support roll 152, and the heating belt 151 is heated from the inner peripheral surface side.
For example, spring members (not shown) that press the heating belt 151 outward are disposed at both ends of the support rolls 152 and 154.

  The pressure roll 156 is rotationally driven by the rotational force of a motor (not shown), and the fixed pad 153 is pressed against the pressure roll 156 via a heating belt 151 by an urging means such as a spring (not shown). Yes. Thus, as the pressure roll 156 rotates in the direction of arrow R, the heating belt 151 rotates in the direction of arrow S following the pressure roll 156.

  When a sheet (not shown) having an unfixed toner image is conveyed and guided to a nipping area (nip portion) where the heating belt 151 and the pressure roll 156 are in contact with each other, pressure and heat acting on the nipping area. And is fixed by.

  In the fixing device 150 according to the second embodiment, a form in which a halogen heater (halogen lamp) is applied as an example of a heating source has been described. However, the invention is not limited to this, and a radiation lamp heating element (radiation (infrared ray) other than the halogen heater is used. Etc.), resistance heating elements (heating elements that generate Joule heat by passing a current through the resistance: for example, a film having a thick film resistance formed on a ceramic substrate and fired) May be.

≪Image forming device≫
Next, the image forming apparatus according to the present embodiment will be described.
The image forming apparatus of the present embodiment includes an image carrier, a charging unit that charges the surface of the image carrier, a latent image forming unit that forms a latent image on the surface of the charged image carrier, and the latent image as a toner. Developing means for forming a toner image by developing, a transfer means for transferring the toner image to a recording medium, and a fixing means for fixing the toner image to the recording medium. The fixing device according to this embodiment is applied as the fixing unit.

The image forming apparatus according to the present embodiment will be described below with reference to the drawings.
FIG. 9 is a schematic configuration diagram showing the configuration of the image forming apparatus according to the present embodiment.

  As shown in FIG. 9, the image forming apparatus 100 according to the present embodiment is, for example, an intermediate transfer type image forming apparatus generally called a tandem type, and a plurality of toner images of each color component are formed by an electrophotographic system. Image forming units 1Y, 1M, 1C, and 1K, and a primary transfer unit 10 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 15. The secondary transfer unit 20 that collectively transfers (secondary transfer) the superimposed toner image transferred onto the intermediate transfer belt 15 onto the paper K that is a recording medium, and the fixing that fixes the secondary transferred image onto the paper K. Device 150. Further, the image forming apparatus 100 includes a control unit 40 that controls the operation of each device (each unit).

  This fixing device 150 is the fixing device 150 according to the second embodiment described above. Note that the image forming apparatus 100 may include the fixing device 60 according to the first embodiment described above.

  Each of the image forming units 1Y, 1M, 1C, and 1K of the image forming apparatus 100 includes a photoconductor 11 that rotates in the arrow A direction as an example of an image holding body that holds a toner image formed on the surface.

  A charger 12 for charging the photosensitive member 11 is provided around the photosensitive member 11 as an example of a charging unit, and a laser exposure device for writing an electrostatic latent image on the photosensitive member 11 as an example of a latent image forming unit. 13 (the exposure beam is indicated by Bm in the figure) is provided.

  Further, around the photosensitive member 11, as an example of a developing unit, a developing device 14 that accommodates each color component toner and visualizes the electrostatic latent image on the photosensitive member 11 with the toner is provided. A primary transfer roll 16 for transferring the color component toner images formed thereon onto the intermediate transfer belt 15 by the primary transfer unit 10 is provided.

  Further, a photoconductor cleaner 17 for removing residual toner on the photoconductor 11 is provided around the photoconductor 11, and a charger 12, a laser exposure device 13, a developing device 14, a primary transfer roll 16, and a photoconductor cleaner. Seventeen electrophotographic devices are sequentially arranged along the rotation direction of the photoconductor 11. 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 15. Has been.

The intermediate transfer belt 15 as an intermediate transfer member is constituted by a film-like pressure belt containing a resin such as polyimide or polyamide as a base layer and containing an appropriate amount of an antistatic agent such as carbon black. The volume resistivity is 10 ⁶ Ωcm or more and 10 ¹⁴ Ωcm or less, and the thickness is, for example, about 0.1 mm.

  The intermediate transfer belt 15 is circulated (rotated) by various rolls at a speed determined in the B direction shown in FIG. As these various rolls, a drive roll 31 that is driven by a motor (not shown) having excellent constant speed to rotate the intermediate transfer belt 15, and an intermediate transfer belt that extends substantially linearly along the arrangement direction of the photoreceptors 11. 15, a support roll 32 that supports the intermediate transfer belt 15, a tension applying roll 33 that functions as a correction roll that applies a constant tension to the intermediate transfer belt 15 and prevents the intermediate transfer belt 15 from meandering, and a back roll provided in the secondary transfer unit 20. 25. A cleaning back roll 34 is provided in a cleaning unit that scrapes off residual toner on the intermediate transfer belt 15.

The primary transfer unit 10 includes a primary transfer roll 16 that is disposed to face the photoconductor 11 with the intermediate transfer belt 15 interposed therebetween. The primary transfer roll 16 includes a shaft and a sponge layer as an elastic layer fixed around the shaft. The shaft is a cylindrical bar made of metal such as iron or SUS. The sponge layer is a sponge-like cylindrical roll formed of a blend rubber of NBR, SBR, and EPDM containing a conductive agent such as carbon black and having a volume resistivity of 10 ^7.5 Ωcm or more and 10 ^8.5 Ωcm or less.

  The primary transfer roll 16 is placed in pressure contact with the photoreceptor 11 with the intermediate transfer belt 15 in between. Further, the primary transfer roll 16 has a voltage (primary polarity) opposite to the toner charging polarity (negative polarity; the same applies hereinafter). Transfer bias) is applied. As a result, the toner images on the respective photoconductors 11 are sequentially electrostatically attracted to the intermediate transfer belt 15 so that the superimposed toner images are formed on the intermediate transfer belt 15.

  The secondary transfer unit 20 includes a back roll 25 and a secondary transfer roll 22 disposed on the toner image holding surface side of the intermediate transfer belt 15.

The back roll 25 is made of a tube of EPDM and NBR blend rubber with carbon dispersed on the surface, and the inside is made of EPDM rubber. And it is formed so that the surface resistivity may be 10 ⁷ Ω / □ or more and 10 ¹⁰ Ω / □ or less, and the hardness is set to, for example, 70 degrees (Asker C: manufactured by Kobunshi Keiki Co., Ltd., the same shall apply hereinafter). The The back roll 25 is disposed on the back side of the intermediate transfer belt 15 to constitute a counter electrode of the secondary transfer roll 22, and a metal power supply roll 26 to which a secondary transfer bias is stably applied is disposed in contact. ing.

On the other hand, the secondary transfer roll 22 includes a shaft and a sponge layer as an elastic layer fixed around the shaft. The shaft is a cylindrical bar made of metal such as iron or SUS. The sponge layer is a sponge-like cylindrical roll formed of a blend rubber of NBR, SBR, and EPDM containing a conductive agent such as carbon black and having a volume resistivity of 10 ^7.5 Ωcm or more and 10 ^8.5 Ωcm or less.

  The secondary transfer roll 22 is placed in pressure contact with the back roll 25 with the intermediate transfer belt 15 interposed therebetween. Further, the secondary transfer roll 22 is grounded and a secondary transfer bias is formed between the secondary transfer roll 22 and the back roll 25, and the secondary transfer roll 22 is grounded. The toner image is secondarily transferred onto the paper K conveyed to the transfer unit 20.

  Further, on the downstream side of the secondary transfer portion 20 of the intermediate transfer belt 15, an intermediate transfer belt that removes residual toner and paper dust on the intermediate transfer belt 15 after the secondary transfer and cleans the surface of the intermediate transfer belt 15. A cleaner 35 is provided so as to be able to contact and separate.

  The intermediate transfer belt 15, the primary transfer unit 10 (primary transfer roll 16), and the secondary transfer unit 20 (secondary transfer roll 22) 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) 42 that generates a reference signal serving as a reference for taking image forming timings in the image forming units 1Y, 1M, 1C, and 1K. It is arranged. Further, an image density sensor 43 for adjusting image quality is disposed on the downstream side of the black image forming unit 1K. The reference sensor 42 recognizes a mark provided on the back side of the intermediate transfer belt 15 and generates a reference signal. In response to an instruction from the control unit 40 based on the recognition of the reference signal, each image forming unit 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 50 that stores the paper K, and the paper K accumulated in the paper storage unit 50 is taken out at a predetermined timing. A paper feed roll 51 that transports the paper K, a transport roll 52 that transports the paper K fed by the paper feed roll 51, a transport guide 53 that feeds the paper K transported by the transport roll 52 to the secondary transfer unit 20, and a secondary transfer A conveyance belt 55 that conveys the sheet K conveyed after the secondary transfer by the roll 22 to the fixing device 150 and a fixing entrance guide 56 that guides the sheet K to the fixing device 150 are provided.

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) or a personal computer (PC) (not shown) is subjected to image processing by an image processing device (not shown), and then the image forming unit 1Y. , 1M, 1C, 1K, image forming work is executed.

  In the image processing apparatus, input reflectance data is subjected to image processing such as shading correction, position shift correction, brightness / color space conversion, gamma correction, frame erasing, color editing, and moving editing. Is done. The image data that has undergone image processing is converted into color material gradation data of four colors, Y, M, C, and K, and is output to the laser exposure unit 13.

  The laser exposure unit 13 irradiates each of the photoconductors 11 of the image forming units 1Y, 1M, 1C, and 1K with, for example, an exposure beam Bm emitted from a semiconductor laser in accordance with the input color material gradation data. . In each of the photoreceptors 11 of the image forming units 1Y, 1M, 1C, and 1K, the surface is charged by the charger 12, and then the surface is scanned and exposed by the laser exposure unit 13 to form an electrostatic latent image. The formed electrostatic latent images are developed as toner images of respective colors Y, M, C, and K by the respective image forming units 1Y, 1M, 1C, and 1K.

  The toner images formed on the photoconductors 11 of the image forming units 1Y, 1M, 1C, and 1K are transferred onto the intermediate transfer belt 15 in the primary transfer unit 10 where the photoconductors 11 and the intermediate transfer belt 15 are in contact with each other. The More specifically, in the primary transfer portion 10, a voltage (primary transfer bias) having a polarity opposite to the toner charging polarity (minus polarity) is applied to the base material of the intermediate transfer belt 15 by the primary transfer roll 16, and the toner image. Are sequentially superimposed on the surface of the intermediate transfer belt 15 to perform primary transfer.

  After the toner images are sequentially primary transferred onto the surface of the intermediate transfer belt 15, the intermediate transfer belt 15 moves and the toner image is conveyed to the secondary transfer unit 20. When the toner image is conveyed to the secondary transfer unit 20, the conveyance unit rotates the paper feed roll 51 in accordance with the timing at which the toner image is conveyed to the secondary transfer unit 20. A size paper K is supplied. The paper K supplied by the paper feed roll 51 is transported by the transport roll 52, and reaches the secondary transfer unit 20 through the transport guide 53. Before reaching the secondary transfer unit 20, the sheet K is temporarily stopped, and the registration roll (not shown) rotates in accordance with the movement timing of the intermediate transfer belt 15 on which the toner image is held. And the position of the toner image are aligned.

  In the secondary transfer unit 20, the secondary transfer roll 22 is pressed against the back roll 25 via the intermediate transfer belt 15. At this time, the sheet K conveyed at the same timing is sandwiched between the intermediate transfer belt 15 and the secondary transfer roll 22. At this time, when a voltage (secondary transfer bias) having the same polarity as the toner charging polarity (negative polarity) is applied from the power supply roll 26, a transfer electric field is formed between the secondary transfer roll 22 and the back roll 25. Is done. The unfixed toner image held on the intermediate transfer belt 15 is collectively electrostatically transferred onto the paper K in the secondary transfer unit 20 pressed by the secondary transfer roll 22 and the back roll 25. The

  Thereafter, the sheet K on which the toner image has been electrostatically transferred is conveyed as it is while being peeled off from the intermediate transfer belt 15 by the secondary transfer roll 22, and is conveyed downstream of the secondary transfer roll 22 in the sheet conveyance direction. It is conveyed to the belt 55. The conveyance belt 55 conveys the paper K to the fixing device 150 in accordance with the optimum conveyance speed in the fixing device 150. The unfixed toner image on the paper K conveyed to the fixing device 150 is fixed on the paper K by being subjected to a fixing process with heat and pressure by the fixing device 150. Then, the sheet K on which the fixed image is formed is conveyed to a paper discharge container (not shown) provided in the discharge unit of the image forming apparatus.

  On the other hand, after the transfer onto the paper K is completed, the residual toner remaining on the intermediate transfer belt 15 is conveyed to the cleaning unit as the intermediate transfer belt 15 rotates, and is cleaned by the cleaning back roll 34 and the intermediate transfer belt cleaner 35. It is removed from the intermediate transfer belt 15.

  The image forming apparatus according to the present embodiment has been described above. However, the present embodiment is not construed as being limited to the above-described aspect, and various modifications, changes, and improvements may be made.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. In the following, “parts” and “%” represent mass standards unless otherwise specified.

[Example 1]
-Fabrication of substrate-
Carbon black (trade name Special Black 4 manufactured by Orion Engineered Carbons Co., Ltd.) having an amount of 27 parts with respect to 100 parts of polyamic acid was dispersed using N-methylpyrrolidone (NMP) as a solvent to obtain a solid content concentration of 18%. A polyamic acid solution (manufactured by JFE Chemical Co., Ltd., trade name JIV300H) was prepared, and this was used as a coating solution (1) (coating solution for the outermost peripheral layer).
In addition, a polyamic acid solution in which polytetrafluoroethylene (PTFE) particles (trade name: Lubron L5, manufactured by Daikin Industries, Ltd.) with an amount of 10 parts with respect to 100 parts of polyamic acid are further mixed with the coating liquid (1). This was prepared and used as a coating solution (2) (coating solution for the innermost peripheral layer).

  The coating liquid (2) was applied to the outer surface of a SUS cylindrical mold using a spiral coating apparatus shown in FIGS. 5 and 6 and dried at 140 ° C. for 30 minutes. Subsequently, the coating liquid (1) was applied to the outer peripheral surface of the coating layer of the coating liquid (2) by a spiral coating apparatus shown in FIGS. 5 and 6 and dried at 140 ° C. for 30 minutes. Thereafter, the coating film is further heated at 320 ° C. for 1 hour and baked. After the heating is completed, the coating film is demolded to sequentially form a 50 μm PTFE particle-dispersed polyimide layer (innermost circumferential layer) and a 30 μm polyimide layer ( The outermost peripheral layer) was obtained.

-Formation of elastic layer-
First, a two-component thermosetting resin X-34-2086-A / B (manufactured by Shin-Etsu Chemical Co., Ltd., with a filler) was stirred to obtain a liquid silicone rubber coating solution for forming an elastic layer.

Next, an elastic layer was formed on the substrate by the following method.
The base was inserted into an elastic layer coating mold and placed on a turntable that rotated in the circumferential direction while keeping the mold axial direction horizontal. While rotating the mold at 100 rpm, the helical silicone coating apparatus shown in FIGS. 5 and 6 moves the liquid silicone rubber coating liquid for forming the elastic layer from the nozzle at a rate of 160 mm per minute from the end of the mold at 45 ml per minute. While discharging. The discharged silicone rubber coating liquid was leveled with a flat SUS plate having a thickness of 0.1 mm as the nozzle was moved, and held while being rotated at 50 rpm for 5 minutes. Thereafter, drying was performed at 110 ° C. for 20 minutes in a rotary drying furnace, followed by vulcanization at 210 ° C. for 1 hour. The film thickness of the obtained elastic layer was 450 μm.

-Formation of surface layer-
A 35 μm-thick tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) tube having a diameter 2% smaller than the outer diameter of the tubular body formed up to the elastic layer is prepared, and the inner diameter is 0.8 from the outer diameter of the tubular body. A PFA tube was set on the inner periphery of the outer mold having a% large diameter. Next, with the tubular body formed up to the elastic layer inserted inside the PFA tube, the PFA tube is removed from the outer mold and coated on the outer periphery of the elastic layer, heated at 200 ° C. for 30 minutes, and a surface with a film thickness of 35 μm A layer was formed.
The fixing belt 1 was produced through the above steps.

[Comparative Example 1]
In the production of the substrate of Example 1, except that the coating solution (1) was used alone without using the coating solution (2), and a single layer structure film was formed by the above-described method to obtain an 80 μm polyimide film, A fixing belt was produced by the method described in Example 1.

[Comparative Example 2]
In the production of the substrate of Example 1, instead of the coating liquid (1) and the coating liquid (2), a fluorinated polyamic acid solution that does not contain fluororesin particles and can form a fluorinated polyimide (manufactured by Hitachi Chemical Co., Ltd., A fixing belt was prepared by the method described in Example 1 except that a single layer structure film was formed by the above-described method using only the trade name OPI) to obtain an 80 μm fluorinated polyimide film.

[Comparative Example 3]
In the production of the substrate of Example 1, a film having a single layer structure was formed by the above-described method using only the coating liquid (2) without using the coating liquid (1), and an 80 μm polyimide containing PTFE particles. A fixing belt was produced by the method described in Example 1 except that the film was used.

[Example 2]
A fixing belt was produced by the method described in Example 1 except that the substrate in Example 1 was a single-layer substrate produced by the following method.
-Fabrication of substrate-
Using a cylindrical mold, while rotating at a centrifugal acceleration of 5.0 times the gravitational acceleration, the coating liquid (2) was applied to the inner peripheral surface and cured by heating to produce a polyimide film having an average film thickness of 80 μm. Subsequently, the prepared polyimide film was cut into a sheet shape, and then the ends were bonded together so that the mold non-contact surface was on the outer peripheral surface side to prepare a tubular substrate.

Example 3
A fixing belt was produced by the method described in Example 1 except that the substrate in Example 1 was a single-layer substrate produced by the following method.
-Fabrication of substrate-
A polyamic acid solution prepared by further mixing polytetrafluoroethylene (PTFE) particles (Daikin Kogyo Co., Ltd., trade name: Lubron L2) with an amount of 10 parts with respect to 100 parts of polyamic acid to the coating solution (1) is prepared. This was designated as coating solution (3). Using a cylindrical mold, while rotating at a centrifugal acceleration of 2.0 times the gravitational acceleration, the coating liquid (3) was applied to the inner peripheral surface and cured by heating to produce a polyimide film with an average film thickness of 80 μm. This was used as a substrate.

Example 4
A fixing belt was produced by the method described in Example 1 except that the substrate in Example 1 was a single-layer substrate produced by the following method.
-Fabrication of substrate-
The coating liquid (2) is applied to the outer surface of a cylindrical mold made of SUS by the spiral coating apparatus shown in FIGS. 5 and 6, and subsequently, the coating liquid is applied to the outer peripheral surface of the coating layer of the coating liquid (2). (1) was applied by a spiral coating apparatus shown in FIGS. 5 and 6 and dried at 140 ° C. for 30 minutes. Thereafter, the substrate was further heated at 320 ° C. for 1 hour and baked, and the coating film was removed after the heating to obtain a substrate having PTFE particles on the inner peripheral surface side.

Example 5
A fixing belt was produced by the method described in Example 1 except that the substrate in Example 1 was a single-layer substrate produced by the following method.
-Fabrication of substrate-
A surfactant (Megafac, manufactured by DIC) was added to the coating liquid (2) so as to be 20% by mass with respect to the PTFE particles to obtain a coating liquid (4). The coating liquid (4) was applied to the outer surface of a SUS cylindrical mold using a spiral coating apparatus shown in FIGS. 5 and 6 and dried at 140 ° C. for 30 minutes. Thereafter, the substrate was further heated at 320 ° C. for 1 hour and baked, and the substrate was obtained by removing the coating film after completion of the heating.

Example 6
In the production of the substrate of Example 1, the polyamic acid solution used in the coating solution (2) (the coating solution for the innermost peripheral layer) was replaced with a polyamic acid solution (trade name, manufactured by Hitachi Chemical Co., Ltd.) that becomes a fluorine-modified polyimide resin. A fixing belt was produced by the method described in Example 1 except that the change was made to (OPI).

-Evaluation method-
<Durability>
A belt is stretched over the evaluation device, and the condition is maintained at 190 ° C., belt tension 40 N, pressure roll nip pressure 10 kgf / mm, and rotation speed 500 mm / sec. Evaluation was made according to the following criteria.
-Oil retention state A: The presence of oil can be confirmed by observation with a microscope (VHX, Keyence) B: The presence of oil cannot be confirmed by observation with a microscope (VHX, Keyence)-Wear state A: Change value of roughness Ra with the initial value is less than 0.3 μm on the inner surface roughness meter (Surfcom, Tokyo Seimitsu Co., Ltd.) B: Roughness Ra with the initial value on the inner surface roughness meter (Surfcom, Tokyo Seimitsu Co., Ltd.) Change value of 0.3μm or more

<Adhesiveness>
A strip-shaped test piece having a width of 15 mm, which was allowed to stand under the condition of 230 ° C. × 100 Hr, was prepared. Next, it is heated to 200 ° C. on a hot plate, a T-type peel test described in JIS-6854-3 (1999) is performed, and the presence or absence of peeling between the elastic layer and the substrate is observed. It was evaluated by.
A: 3 × 10 ⁻³ kN / mm or more B: Less than 3 × 10 ⁻³ kN / mm

  In addition, regarding [*] shown in Table 1 above, in Example 6, the amount of oil in the oil retention was smaller than in other Examples 1 to 5.

1Y, 1M, 1C, 1K Image forming unit 11 Photoconductor (image carrier)
12 Charger (charging means)
13 Laser exposure device (latent image forming means)
14 Developer (Developing means)
15 Intermediate transfer belt 16 Primary transfer roll (transfer means)
17 Photoconductor cleaner 22 Secondary transfer roll (transfer means)
25 Back roll 26 Power supply roll 31 Drive roll 32 Support roll 33 Tension applying roll 34 Cleaning back roll 35 Intermediate transfer belt cleaner 40 Control unit 50 Paper storage unit 51 Paper feed roll 52 Transport roll 53 Transport guide 55 Transport belt 56 Fixing entrance guide 60 Fixing device 61 Heating roller 62 Pressure belt 63 Belt running guide 64 Press pad 64a Front clamping member 64b Peeling clamping member 65 Holding member 66 Halogen lamp 67 Lubricant supply device 68 Sliding member 69 Temperature sensitive element 70 Peeling member 71 Peeling Nail 72 Holding member 100 Image forming apparatus 110A, 110B Image fixing tubular body 112, 112A, 112B Base 112E Base forming coating liquid 112N Surface of inner peripheral surface of base 112T Coating film 114 Elastic layer 116 Fluoro resin particle 118 Surface Layer 120 recess 50 fixing device 151 heating belt (an example of a first rotating body)
152 Support Roll 153 Fixed Pad 154 Support Roll 156 Pressure Roll (Example of Second Rotating Body)
157 Halogen heater (an example of heating means)
200 Device for performing spiral coating 210 Cylindrical core (holding means)
220 Application part (application means)
222 Storage part 224 Supply pipe 226 Pump 228 Nozzle 230 Roll (smoothing means)
1121 Innermost layer 1122 Outermost layer

Claims (6)

A substrate containing a resin and fluororesin particles, wherein the presence rate (area ratio) of the fluororesin particles on the inner peripheral surface side is higher than the presence rate (area ratio) of the fluororesin particles on the outer peripheral surface side When,
An elastic layer on the outer peripheral surface side of the substrate;
A tubular body for image fixing, comprising:   The substrate has a multilayer structure having at least an innermost peripheral layer and an outermost peripheral layer, and the concentration of the fluororesin particles in the innermost peripheral layer is higher than the concentration of the fluororesin particles in the outermost peripheral layer. The tubular body for image fixing described in 1.   2. The tubular body for image fixing according to claim 1, wherein the substrate has a single layer structure, and the fluororesin particles are unevenly distributed on the inner peripheral surface side in the substrate having the single layer structure.   The tubular body for image fixing according to any one of claims 1 to 3, wherein the resin is a resin that does not contain a fluorine atom in its structure.   A fixing device comprising the image fixing tubular body according to claim 1. An image carrier,
Charging means for charging the surface of the image carrier;
Latent image forming means for forming a latent image on the surface of the charged image carrier;
Developing means for developing the latent image with toner to form a toner image;
Transfer means for transferring the toner image to a recording medium;
Fixing means that is a fixing device according to claim 5, wherein the toner image is fixed on a recording medium;
An image forming apparatus comprising at least

Images