JP5979298B2 - Cylindrical molded body, cylindrical molded body unit, member for image forming apparatus, and image forming apparatus - Google Patents

Description

  The present invention relates to a cylindrical molded body, a cylindrical molded body unit, a member for an image forming apparatus, and an image forming apparatus.

Cylindrical molded bodies have been developed in various technical fields including image forming apparatus members.
For example, a fixing member (heating belt, pressure belt) using a fluorinated polyimide resin has been proposed (see Patent Document 1).
There has also been proposed a fixing member in which fluororesin particles are dispersed in a polyimide resin and the fluororesin is dispersed and unevenly distributed on the polyimide surface (see Patent Document 2).

As a method for introducing fluorine atoms into the surface layer of the intermediate transfer belt, a method of applying a surfactant containing fluorine atoms together with a binder such as polyimide resin has been proposed (see Patent Documents 3 and 4).
In addition, a method of applying a fluorine resin containing a fluorine atom to a belt substrate has been proposed (see Patent Document 5).

A fixing belt using a material mainly composed of a fluororesin for the surface layer has also been proposed (see Patent Documents 6 to 10).
In addition, a fixing belt using a polyimide resin and a fluororesin in combination on the surface layer has been proposed (see Patent Document 11).
In addition, a fixing belt is also proposed in which a layer using both polyimide resin and fluororesin is provided on the inner peripheral surface (see Patent Document 12).
A fixing roll using a polyimide resin and a fluororesin in combination on the surface layer has also been proposed (see Patent Document 13).

Japanese Patent No. 3069041 Japanese Patent No. 3260679 JP 7-156287 A JP 2004-29769 A JP 2004-125905 A JP 2007-293028 A JP 2004-160431 A Japanese Patent Laid-Open No. 11-15303 JP-A-10-282818 Japanese Patent Application Laid-Open No. 7-199691 JP 2006-259248 A Japanese Patent Laid-Open No. 2005-257789 JP 2007-293028 A

  The subject of this invention is providing the cylindrical molded object by which the local crack of the molten layer or the softening layer of the polyimide-type resin particle was suppressed even if it contained the fluororesin particle.

The above problem is solved by the following means. That is,
The invention according to claim 1
A layered mixture comprising a thermoplastic polyimide resin particle having a volume average particle size of 40 μm or more and 2 mm or less, excluding polyetherimide resin particles, and a fluororesin particle having a volume average particle size of 0.5 μm or more and 20 μm or less. A molten layer or a softened layer of the polyimide resin particles, or a thermoplastic polyimide resin particle having a volume average particle diameter of 40 μm or more and 2 mm or less, and a fluorine resin particle having a volume average particle diameter of 0.5 μm or more and 3 μm or less. A cylindrical molded body having a molten layer or a softened layer of the polyimide-based resin particles in a layered mixture containing.

The invention according to claim 2
The cylindrical molded body is composed of a laminate of two or more layers,
The cylindrical molded body according to claim 1, which has a molten layer or a softened layer of the polyimide resin particles as an outermost layer.

The invention according to claim 3
The cylindrical molded body is composed of a laminate of two or more layers,
The cylindrical molded body according to claim 1 or 2, wherein the layer in contact with the melted layer or the softened layer of the polyimide resin particles is a layer configured to contain a polyimide resin.

The invention according to claim 4
The cylindrical molded body according to any one of claims 1 to 3, wherein the molten layer or the softened layer of the polyimide resin particles contains a conductive material.

The invention according to claim 5
5. A cylindrical molded body according to claim 1, and a plurality of rolls that span the cylindrical molded body in a tensioned state, and is attached to and detached from the image forming apparatus. Cylindrical molded unit.

The invention according to claim 6
The member for image forming apparatuses comprised with the cylindrical molded object of any one of Claims 1-4.

The invention according to claim 7 provides:
An image forming apparatus comprising the member for an image forming apparatus according to claim 6.

According to the invention which concerns on Claim 1, the molten layer or softening layer of a polyimide-type resin particle is not the molten layer or the softening layer of the said polyimide-type resin particle of the layered mixture containing a thermoplastic polyimide-type resin particle and a fluororesin particle. Compared to the case, a cylindrical molded body in which local cracking of the molten layer or the softened layer of the polyimide resin particles is suppressed can be provided even if the fluororesin particles are included.
According to the invention which concerns on Claim 2, compared with the case where an outermost layer is not the molten layer or the softening layer of the said polyimide resin particle of the layered mixture containing a thermoplastic polyimide resin particle and a fluororesin particle, A cylindrical molded body in which local cracks are suppressed can be provided.
According to the invention concerning Claim 3, compared with the case where the layer which contacts the melted layer or softened layer of the polyimide resin particles is not configured to contain the polyimide resin, the molten layer or softened layer of the polyimide resin particles and It is possible to provide a cylindrical molded body in which peeling from the contacting layer is suppressed.
According to the invention according to claim 1, compared with the case where the volume average particle diameter of the fluororesin particles is not within the above range, the cylindrical molded body in which the local cracking of the molten layer or the softened layer of the polyimide resin particles is suppressed. Can be provided.
According to the invention of claim 4, the molten layer or softened layer of polyimide resin particles is a molten layer or softened layer of polyimide resin particles in a layered mixture containing thermoplastic polyimide resin particles and fluororesin particles. Compared with the case where it does not, even if it contains a conductive material with a fluororesin particle, the cylindrical molded object by which the local crack of the molten layer or the softening layer of the polyimide-type resin particle was suppressed can be provided.

  According to the invention according to claim 5, compared to a case where a cylindrical molded body having a molten layer or a softened layer of the polyimide resin particles of a layered mixture containing thermoplastic polyimide resin particles and fluororesin particles is not applied, Even when the fluororesin particles are included, a cylindrical molded body unit including a cylindrical molded body in which local cracking of the melted layer or the softened layer of the polyimide resin particles is suppressed can be provided.

According to the invention which concerns on Claim 6, compared with the case where the cylindrical molded object which has the molten layer or the softening layer of the said polyimide resin particle of the layered mixture containing a thermoplastic polyimide resin particle and a fluororesin particle is not applied. The member for an image forming apparatus in which image defects caused by local cracks in the molten layer or the softened layer of the polyimide resin particles in the cylindrical molded body can be provided.
According to the invention which concerns on Claim 7, compared with the case where the cylindrical molded object which has the molten layer or the softening layer of the said polyimide resin particle of the layered mixture containing a thermoplastic polyimide resin particle and a fluororesin particle is not applied. It is possible to provide an image forming apparatus in which image defects due to local cracks in the molten layer or the softened layer of the polyimide resin particles in the cylindrical molded body are suppressed.

It is a schematic perspective view which shows the cylindrical molded object which concerns on this embodiment. It is an AA schematic sectional drawing of FIG. It is a schematic sectional drawing (equivalent to the AA schematic sectional drawing of FIG. 1) which shows the cylindrical molded object which concerns on other this embodiment. It is the schematic plan view (A) and schematic sectional drawing (B) which show an example of a circular electrode. It is a schematic perspective view which shows the cylindrical molded object unit which concerns on this embodiment. 1 is a schematic configuration diagram illustrating an image forming apparatus according to an exemplary embodiment. It is a schematic block diagram which shows the image forming apparatus which concerns on other embodiment.

  Hereinafter, embodiments will be described in detail with reference to the drawings.

(Cylindrical compact)
FIG. 1 is a schematic perspective view showing a cylindrical molded body according to the embodiment. FIG. 2 is a schematic cross-sectional view taken along the line AA of FIG.

The cylindrical molded body 10 (hereinafter referred to as an endless belt 10) according to the present embodiment is formed, for example, in an endless shape, as shown in FIGS. 1 and 2, for example, a base material layer 12 having a thickness of 30 μm or more and 80 μm or less. For example, and the outermost layer 11 having a thickness of 5 μm or more and 70 μm or less provided on the outer peripheral surface of the base material layer 12.
And as the outermost layer 11, a molten layer or a softened layer of the polyimide resin particles of a layered mixture containing thermoplastic polyimide resin particles and fluororesin particles (hereinafter sometimes simply referred to as “polyimide resin layer”). Has been applied. However, in this embodiment, the polyimide resin layer has a volume average particle size of 40 μm or more and 2 mm or less, a thermoplastic polyimide resin particle excluding polyetherimide resin particles, and a volume average particle size of 0.5 μm or more and 20 μm or less. A melted layer or a softened layer of the polyimide-based resin particles in a layered mixture containing fluororesin particles, or thermoplastic polyimide-based resin particles having a volume average particle size of 40 μm or more and 2 mm or less, and a volume average particle size of A molten layer or a softened layer of the polyimide resin particles in a layered mixture containing fluororesin particles having a size of 0.5 μm or more and 3 μm or less is applied.
Specifically, the polyimide resin layer as the outermost layer 11 is, for example, a coating film of a solution in which thermoplastic polyimide resin particles and fluororesin particles are dispersed in a solvent (the coating film is a thermoplastic polyimide resin). A layer obtained by subjecting a mixture containing particles and fluororesin particles to a heat treatment) is preferable.
That is, the polyimide resin layer is a layer in which a mixture containing thermoplastic polyimide resin particles and fluororesin particles is formed in a layer shape, and the thermoplastic polyimide resin particles are melted or softened by heating.

In the endless belt 10 according to the present embodiment, local cracking of the outermost layer 11 (that is, the polyimide resin layer) is suppressed by setting the outermost layer 11 formed of the polyimide resin layer to the above-described configuration.
The reason for this is not clear, but is presumed to be as follows.

  Conventionally, a polyimide resin layer containing fluororesin particles is obtained by heating a coating film of a polyimide resin precursor solution in which fluororesin particles are dispersed, or by dispersing fluororesin particles in a molten thermoplastic polyimide resin. It is obtained by forming a layered product.

However, in the polyimide resin layer containing the fluororesin particles by such a technique, the dispersibility of the fluororesin particles before the layer formation tends to be low, and the fluororesin particles are aggregated or unevenly distributed in the obtained polyimide resin layer. It is thought that it is often included. In the case of processing from a polyimide resin precursor solution in which fluororesin particles are dispersed, the polyimide resin as a binder becomes rigid with the imidization reaction of the polyimide resin precursor, and the cohesive force of the polyimide resin increases. Therefore, during the heat treatment, the fluororesin particles are discharged from the binder and agglomeration occurs. Moreover, in the case of processing by dispersing the fluororesin particles in the molten thermoplastic polyimide resin, the fluororesin particles cannot be sufficiently dispersed because the melt viscosity of the thermoplastic polyimide resin is high.
And, for example, when a bending or stretching mechanical load is applied to the polyimide resin layer containing the fluorine resin particles in such a state, is it because of the difference in wettability between the polyimide resin and the fluorine resin particles? It is considered that stress concentrates on the location where the fluororesin particles aggregate and the interface between the fluororesin aggregate and the polyimide resin, and local cracking is likely to occur.

On the other hand, as in the present embodiment, in a state (mixture) in which polyimide resin particles and fluororesin particles are mixed, thermoplastic polyimide resin particles or fluororesin particles are hardly aggregated, and the thermoplastic polyimide It is considered that a state where the resin particles and the fluororesin particles are mixed with each other can be created.
In order to create a state in which such particles are mixed with each other, for example, it is considered to be dispersed in thermoplastic polyimide resin particles, fluororesin particles, and a solvent. This does not involve the imide reaction of the polyimide resin precursor seen during processing from the polyimide resin precursor solution in which the fluororesin particles are dispersed, so that the aggregation of the fluororesin particles is reduced. Compared with processing from a polyimide resin precursor solution in which dispersed fluororesin particles are dispersed or processing by dispersing fluororesin particles in a molten thermoplastic polyimide resin, the viscosity of the dispersion is low, making it easy This is because it is thought that it can be dispersed.

When the polyimide resin particles are melted in a mixed state (mixture) of the polyimide resin particles and the fluorine resin particles, that is, in a state where the particles are mixed with each other, specifically, for example, thermoplastic polyimide resin particles When the coating film of the solution in which the resin particles and the fluororesin particles are dispersed in a solvent is heated, it is considered that the fluororesin particles are included in the polyimide resin layer in a state where aggregation and uneven distribution are suppressed. .
That is, it is considered that the fluorine resin particles are easily dispersed and contained in the polyimide resin layer.

For this reason, in the endless belt 10 which concerns on this embodiment, it is thought that the local crack of the outermost layer 11 (an example of a polyimide resin layer) comprised with the polyimide resin layer is suppressed.
That is, the endless belt 10 according to the present embodiment is useful as a member for an image forming apparatus, for example, because local cracking of the outermost layer 11 is suppressed against mechanical loads such as bending and stretching. .
In the image forming apparatus including the image forming apparatus member, image defects caused by local cracks in the outermost layer 11 (an example of a polyimide resin layer) are suppressed.

  Hereinafter, constituent materials and characteristics of the endless belt 10 according to the present embodiment will be described in detail.

First, the outermost layer 11 will be described.
The outermost layer 11 is, for example, a polyimide resin layer that includes fluorine resin particles, and is a polyimide resin layer that is a mixture including thermoplastic polyimide resin particles and fluorine resin particles.
Specifically, the polyimide resin layer as the outermost layer 11 is obtained by, for example, subjecting a coating film of a solution in which thermoplastic polyimide resin particles and fluororesin particles are dispersed in a solvent to heat treatment. It is the obtained layer.

Depending on the use of the endless belt 10 (for example, when applied to a transfer belt such as an intermediate transfer member [intermediate transfer belt] or a transfer transfer member [transport transfer belt]), the polyimide resin layer as the outermost layer 11 is used. A conductive material is included.
In this case, for example, the polyimide resin layer as the outermost layer 11 is, for example, a solution in which thermoplastic polyimide resin particles and fluororesin particles are dispersed in a solvent, and the conductive material is also dispersed or dissolved in the solvent. It is the layer obtained by heat-processing with respect to the coating film of the solution.

The thermoplastic polyimide resin particles will be described.
The thermoplastic polyimide resin that constitutes the thermoplastic polyimide resin particles is, for example, a resin that can be melt-molded by heating, and is a polymer having repeating units of an imide ring structure. With respect to the thermal characteristics of the thermoplastic polyimide resin, it is preferable that, from the viewpoint of processing, it has a melting temperature or softening temperature that can be melted, and the melting temperature or softening temperature is lower than the thermal decomposition temperature.

  Specific examples of the thermoplastic polyimide resin include thermoplastic polyimide resins, thermoplastic polyamideimide resins, thermoplastic polyetherimide resins, and thermoplastic polyesterimide resins.

  Thermoplastic polyimide resin is produced in two stages, for example, from polyamic acid obtained by dehydration condensation polymerization of diamine compound and tetracarboxylic dianhydride, and further dehydrating imidization reaction, or diisocyanate and tetracarboxylic acid The dianhydride dianhydride is polymerized in one step.

  Thermoplastic polyamideimide is produced, for example, from polyamic acid obtained by dehydrating condensation polymerization of a diamine compound and trimellitic acid in two stages in which dehydrating imidization reaction is further performed, or trimellitic dianhydride and diisocyanate It is produced in one step by polymerizing a compound.

  The thermoplastic polyetherimide is obtained, for example, by dehydration condensation of a diamine compound containing an ether structure and a tetracarboxylic dianhydride, or dehydration condensation polymerization of a diamine compound and a tetracarboxylic dianhydride containing an ether structure. Manufactured from polyamic acid in two stages for further dehydrating imidization reaction, or polymerized diisocyanate compound containing ether structure and tetracarboxylic dianhydride, or tetracarboxylic dianhydride containing diisocyanate compound and ether structure And are produced in one stage.

  The thermoplastic polyesterimide is, for example, a polyamide obtained by dehydration polymerization of a diamine compound containing an ester structure and a tetracarboxylic dianhydride, or by dehydration condensation polymerization of a diamine compound and a tetracarboxylic dianhydride containing an ester structure. Further, it is produced in two steps in which a dehydration imidation reaction is further performed from an acid, or a diisocyanate compound containing an ester structure and a tetracarboxylic dianhydride are polymerized, or a diisocyanate compound and a tetracarboxylic dianhydride containing an ester structure. Examples thereof include those produced by polymerization in one stage.

  A well-known thing can be applied for the monomer for manufacturing these thermoplastic polyimide resins.

The melting temperature or softening temperature of the thermoplastic polyimide resin particles may be, for example, 150 ° C. or higher and 450 ° C. or lower, preferably 200 ° C. or higher and 400 ° C. or lower, more preferably 250 ° C. or higher and 380 ° C. or lower.
Here, the melting temperature is a value determined by the temperature at which the crystalline resin portion represented by the melting point (Tm) melts.
The softening temperature is a value determined by the temperature at which the amorphous resin part melts, which is indicated by the so-called glass transition temperature (Tg).

The thermoplastic polyimide resin particles may be spherical, fibrous, or indefinite as long as they are particulate.
The volume average particle diameter of the thermoplastic polyimide resin particles is, for example, preferably from 0.2 μm to 2 mm, desirably from 0.5 μm to 1 mm, and more desirably from 1 μm to 100 μm. The thermoplastic resin having a large particle size is used after being pulverized so as to have such a volume average particle size.
When the volume average particle size is in the above range, the thermoplastic polyimide resin particles are less likely to aggregate with each other, easily mixed with the fluororesin particles, and smaller than the thickness of the polyimide resin layer. Strength failure (that is, partial strength failure due to partial reduction in resin presence due to the presence of particles) is suppressed, and as a result, local cracking of the polyimide resin layer is easily suppressed.
The volume average particle size is measured by a method such as laser diffraction / scattering particle size distribution measurement or dynamic light scattering method.

The content of the thermoplastic polyimide resin particles (that is, the content of the thermoplastic polyimide resin in the polyimide resin layer) is, for example, 5% by mass or more and 90% by mass or less with respect to the entire components constituting the layer. It is often 20% by mass or more and 80% by mass or less, more preferably 30% by mass or more and 70% by mass or less.
The polyimide resin particles may be used alone or in combination of two or more.

  Here, in addition to the polyimide resin particles, other resin particles may be used in combination. Examples of other resin particles include polyamide resin particles, polyether ether ester resin particles, polyarylate resin particles, polyester resin particles, and polyester resin particles obtained by adding a reinforcing material.

The fluororesin particles will be described.
Examples of the fluororesin constituting the fluororesin particles include a fully fluorinated resin, a partially fluorinated resin, and a fluorinated resin copolymer.
Examples of the fully fluorinated resin include polytetrafluoroethylene (tetrafluorinated resin, abbreviation: PTFE).
Examples of the partially fluorinated resin include polychlorotrifluoroethylene (trifluorinated resin, abbreviation: PCTFE, CTFE), polyvinylidene fluoride (abbreviation: PVDF), polyvinyl fluoride (abbreviation: PVF), and the like.
Fluorinated resin copolymers include perfluoroalkoxy fluororesin (abbreviation: PFA), tetrafluoroethylene / hexafluoropropylene copolymer (abbreviation: FEP), ethylene / tetrafluoroethylene copolymer (abbreviation: ETFE). ), Ethylene / chlorotrifluoroethylene copolymer (abbreviation: ECTFE), polytetrafluoroethylene (tetrafluorinated resin, abbreviation: PTFE), and the like.

The fluororesin particles may be spherical, fibrous, or indefinite as long as they are particulate.
The volume average particle size of the fluororesin particles is, for example, preferably from 0.5 μm to 70 μm, desirably from 1 μm to 50 μm, and more desirably from 2 μm to 20 μm.
When the volume average particle size is in the above range, the fluororesin particles are less likely to aggregate with each other, easily mixed with the thermoplastic polyimide resin particles, and smaller than the thickness of the polyimide resin layer. Strength failure (that is, partial strength failure due to partial reduction in resin presence due to the presence of particles) is suppressed, and as a result, local cracking of the polyimide resin layer is easily suppressed.
The volume average particle size is measured by a method such as laser diffraction / scattering particle size distribution measurement or dynamic light scattering method.

The content of the fluororesin particles (that is, the content of the fluororesin in the polyimide resin layer) is, for example, preferably from 10% by mass to 95% by mass with respect to the total components constituting the layer, and desirably It is 20 mass% or more and 80 mass% or less, More desirably, it is 30 mass% or more and 70 mass% or less.
The fluororesin particles may be used alone or in combination of two or more.

The conductive material will be described.
The conductive material is conductive (for example, a volume resistivity of less than 10 ⁷ Ω · cm, the same applies hereinafter) or semiconductive (eg, a volume resistivity of 10 ⁷ Ω · cm to 10 ¹³ Ω · cm, and the same applies hereinafter). ).
Specific examples of the conductive material include, for example, carbon black (eg, Ketchen black, acetylene black, carbon black whose surface is oxidized), metal (eg, aluminum or nickel), metal oxide compound (eg, yttrium oxide, tin oxide). Etc.), ion conductive materials (for example, potassium titanate, LiCl, etc.), conductive polymers (for example, polyaniline, polypyrrole, polysulfone, polyacetylene, etc.) and the like.

  The conductive material is selected depending on the purpose of use, but from the viewpoint of stability over time of electric resistance and electric field dependency that suppresses electric field concentration due to transfer voltage, the pH is 5 or less (preferably pH 4.5 or less, More preferably, an oxidation-treated carbon black having a pH of 4.0 or less) (for example, carbon black obtained by imparting a carboxyl group, a quinone group, a lactone group, a hydroxyl group, or the like to the surface) is good, and from the viewpoint of imparting electrical durability, A conductive polymer (for example, polyaniline) is preferable.

  In the case where the conductive material is in the form of particles such as carbon black, the primary particle diameter is less than 10 μm, preferably 1 μm or less.

The content of the conductive material is, for example, preferably 1% by mass or more and 50% by mass or less, preferably 2% by mass or more and 40% by mass or less, more preferably 4% by mass or more 30% with respect to the entire components constituting the layer. It is below mass%.
A conductive material may be used individually by 1 type, and may be used together 2 or more types.

Next, the base material layer 12 will be described.
The base material layer 12 includes a resin material. The base material layer 12 is also configured to include a conductive material according to the use of the endless belt 10 (for example, when applied to a transfer belt such as an intermediate transfer member [intermediate transfer belt] or a conveyance transfer member [conveyance transfer belt]). Is done.

The resin material will be described.
As the resin material, the Young's modulus of the resin material varies depending on the thickness of the belt, but is desirably 3500 MPa or more, more desirably 4000 MPa or more, and the mechanical properties as the belt are satisfied. The resin is not limited as long as the above Young's modulus is satisfied. For example, polyimide resin (for example, thermoplastic or thermosetting polyimide resin, polyamideimide resin, polyetherimide resin, polyesterimide resin), polyamide Examples thereof include resins, polyether ether ester resins, polyarylate resins, polyester resins, and polyester resins obtained by adding a reinforcing material.

  The Young's modulus is obtained by performing a tensile test according to JIS K7127 (1999), drawing a tangent line to the curve of the initial strain region of the obtained stress / strain curve, and determining the inclination. As the measurement conditions, a strip-shaped test piece (width 6 mm, length 130 mm), dumbbell No. 1, test speed 500 mm / min, and thickness are measured by each setting of the thickness of the belt body.

  Among the resin materials, a polyimide resin is preferable. Since the polyimide resin (particularly polyimide resin) is a high Young's modulus material, deformation at the time of belt rotation driving is less than that of other resins. Since the outermost layer 11 includes a polyimide resin, the base material layer 12 corresponding to the lower layer in contact with the outermost layer 11 also includes the polyimide resin, so that the outermost layer 11 and the lower layer It is thought that the adhesiveness with the base material layer 12 is improved, and peeling between the layers is suppressed.

The conductive material will be described.
As the conductive material, the same conductive material as that constituting the outermost layer 11 may be used.

Next, the characteristics of the endless belt 10 according to this embodiment will be described.
When the endless belt 10 according to the present embodiment is deformed by 135 ° at a bending radius of 5 mm in the circumferential direction, the outermost layer 11 (polyimide-based resin layer) may not be damaged (broken, broken, etc.). .

  When the endless belt 10 according to the present embodiment is applied to an intermediate transfer member (intermediate transfer belt), the surface resistivity of the outer peripheral surface is 9 (LogΩ / □) or more and 13 (LogΩ / □) or less as a common logarithmic value. Desirably, it is 10 (LogΩ / □) or more and 12 (LogΩ / □) or less. When the common logarithmic value of the surface resistivity exceeds 13 (LogΩ / □), the recording medium and the intermediate transfer member may be electrostatically adsorbed during the secondary transfer, and the recording medium may not be peeled off. On the other hand, if the common logarithmic value of the surface resistivity is less than 9 (LogΩ / □), the holding power of the toner image primarily transferred to the intermediate transfer member may be insufficient, and image quality graininess and image disturbance may occur. . The common logarithm of the surface resistivity is controlled by the type of conductive material and the amount of conductive material added.

Here, the measurement method of the surface resistivity is performed as follows. Measurement is performed according to JIS K6911 using a circular electrode (for example, “UR probe” of Hiresta IP manufactured by Mitsubishi Oil Chemical Co., Ltd.). A method for measuring the surface resistivity will be described with reference to the drawings. FIG. 4 is a schematic plan view (A) and a schematic cross-sectional view (B) showing an example of a circular electrode. The circular electrode shown in FIG. 4 includes a first voltage application electrode A and a plate-like insulator B. The first voltage application electrode A has a cylindrical electrode portion C and a cylindrical ring electrode having an inner diameter larger than the outer diameter of the cylindrical electrode portion C and surrounding the cylindrical electrode portion C at a constant interval. Part D is provided. A belt T is sandwiched between the cylindrical electrode portion C and ring electrode portion D in the first voltage application electrode A and the plate insulator B, and the cylindrical electrode portion C and ring electrode in the first voltage application electrode A are sandwiched between them. The current I (A) that flows when the voltage V (V) is applied between the portion D and the surface D is measured, and the surface resistivity ρs (Ω / □) of the transfer surface of the belt T is calculated by the following equation. Here, in the following formula, d (mm) indicates the outer diameter of the cylindrical electrode portion C, and D (mm) indicates the inner diameter of the ring-shaped electrode portion D.
Formula: ρs = π × (D + d) / (D−d) × (V / I)
The surface resistivity is a circular electrode (UR probe of Hiresta IP manufactured by Mitsubishi Yuka Co., Ltd .: outer diameter Φ16 mm of the cylindrical electrode portion C, inner diameter Φ30 mm, outer diameter Φ40 mm of the ring-shaped electrode portion D), Under a 22 ° C./55% RH environment, a voltage value of 500 V and a current value after application for 10 seconds are obtained and calculated.

  When the endless belt 10 according to the present embodiment is applied to an intermediate transfer member (intermediate transfer belt), the overall volume resistivity is desirably 8 (Log Ωcm) or more and 13 (Log Ωcm) or less as a common logarithmic value. . If the common logarithmic value of the volume resistivity is less than 8 (Log Ωcm), the electrostatic force that holds the charge of the unfixed toner image transferred from the image carrier to the intermediate transfer member is difficult to work. The electrostatic repulsive force between the images and the fringe electric field at the image edge may cause the toner to scatter around the image and form a noisy image. On the other hand, when the common logarithmic value of the volume resistivity exceeds 13 (Log Ωcm), since the charge retention is large, the surface of the intermediate transfer member is charged by the transfer electric field in the primary transfer, so that a static elimination mechanism is required. There is a case. The common logarithmic value of the volume resistivity is controlled by the type of conductive material and the amount of conductive material added.

Here, the volume resistivity is measured in accordance with JIS K6911 using a circular electrode (for example, UR probe of Hiresta IP manufactured by Mitsubishi Yuka Co., Ltd.). A method for measuring the volume resistivity will be described with reference to the drawings. The measurement is performed with the same device as the surface resistivity. However, the circular electrode shown in FIG. 4 includes a second voltage application electrode B ′ instead of the plate-like insulator B at the time of measuring the surface resistivity. Then, the belt T is sandwiched between the cylindrical electrode portion C and the ring-shaped electrode portion D in the first voltage application electrode A and the second voltage application electrode B ′, and the cylindrical electrode portion C in the first voltage application electrode A. The current I (A) that flows when the voltage V (V) is applied between the second voltage application electrode B and the second voltage application electrode B is measured, and the volume resistivity ρv (Ωcm) of the belt T is calculated by the following equation. Here, in the following formula, t represents the thickness of the belt T.
Formula ρv = 19.6 × (V / I) × t
In addition, volume resistivity uses a circular electrode (UR probe of Hiresta IP manufactured by Mitsubishi Oil Chemical Co., Ltd .: outer diameter Φ16 mm of the cylindrical electrode portion C, inner diameter Φ30 mm of the ring-shaped electrode portion D, outer diameter Φ40 mm), Under a 22 ° C./55% RH environment, a voltage value of 500 V and a current value after application for 10 seconds are obtained and calculated.

Moreover, 19.6 shown by the said formula is an electrode coefficient for converting into a resistivity, and it is (pi) d < ² > / 4t from the outer diameter d (mm) of a cylindrical electrode part, and the thickness t (cm) of a sample. Is calculated as The thickness of the belt T is measured using an eddy current film thickness meter CTR-1500E manufactured by Sanko Electronics.

Hereinafter, a method for manufacturing the endless belt 10 according to the present embodiment will be described.
The endless belt 10 will be described with respect to a manufacturing method in which a polyimide resin is used as the resin material of the base material layer 12 and carbon black is included as the conductive material in the base material layer 12 and the outermost layer 11, but is not limited thereto. is not.

  First, a core body is prepared. Examples of the core to be prepared include a cylindrical mold. Examples of the core material include metals such as aluminum, stainless steel, and nickel. The length of the core needs to be longer than the target endless belt, but is preferably 10% to 40% longer than the target endless belt.

Next, a polyamic acid solution in which carbon black is dispersed is prepared as a base layer-forming coating solution.
Specifically, for example, a tetracarboxylic acid dianhydride and a diamine compound are dissolved in an organic polar solvent, and after carbon black is dispersed therein, a polyamic acid solution in which carbon black is dispersed by polymerization is prepared. .
At this time, the monomer concentration (concentration of tetracarboxylic dianhydride and diamine compound in the solvent) in the polyamic acid solution is set according to various conditions, but is preferably 5% by mass or more and 30% by mass or less. The polymerization reaction temperature is preferably set to 80 ° C. or less, particularly preferably 5 ° C. to 50 ° C., and the polymerization reaction time is 5 hours to 10 hours.

Next, the substrate layer forming coating solution is applied to a cylindrical mold as a core material to form a coating film of the substrate layer forming coating solution.
The method of applying the coating liquid to the cylindrical mold is not particularly limited. For example, the method of immersing in the outer peripheral surface of the cylindrical mold, the method of applying to the inner peripheral surface of the cylindrical mold, and the axis being horizontal. A method of applying a spiral mold on the outer peripheral surface or the inner peripheral surface while rotating the cylindrical mold, a method of applying by using a die having a specific distance from the outer periphery of the cylindrical mold, etc. Can be mentioned.

  Next, the coating film of the base layer forming coating solution is dried to form a coating film (dried coating film before imidization) to be a base material layer. The drying conditions are, for example, from 80 ° C. to 200 ° C. for 10 minutes to 60 minutes, 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. It is preferable to rotate the core body at 5 rpm or more and 60 rpm or less with the axial direction of the core body horizontal. The core may be vertical after drying.

Next, a solution (dispersion) in which thermoplastic polyimide resin particles, fluororesin particles, and carbon black are dispersed in a solvent is prepared as a coating liquid for forming the outermost layer.
Specifically, for example, thermoplastic polyimide resin particles, fluororesin particles, and carbon black may be added to a solvent and stirred to prepare a dispersion, or a dispersion of each particle is prepared in advance. These dispersions may be mixed and prepared.

  Here, examples of the solvent used include water, ether solvents (eg, diethyl ether, tetrahydrofuran, dioxane, dioxolane, etc.), alcohol solvents (eg, methanol, ethanol, butanol, etc.), cellosolve alcohols (eg, butyl cellosolve, etc.) , Ester solvents (for example, methyl acetate, ethyl acetate, propyl acetate, butyl acetate ester, etc.), ketone solvents (for example, acetone, methyl ethyl ketone, cyclohexanone, etc.) and the like.

Further, a dispersant for dispersing each particle may be added to the solution (dispersant).
For example, the dispersant for dispersing thermoplastic polyimide resin particles and carbon black (particulate conductive material) may be low molecular weight or high molecular weight, and is selected from cationic, anionic and nonionic. Any type of dispersant may be mentioned, but nonionic polymers are particularly desirable.
Nonionic polymers include poly (N-vinyl-2-pyrrolidone), poly (N, N′-diethylacrylazide), poly (N-vinylformamide), poly (N-vinylacetamide), poly (N -Vinylphthalamide), poly (N-vinylsuccinic acid amide), poly (N-vinylurea), poly (N-vinylpiperidone), poly (N-vinylcaprolactam), poly (N-vinyloxazoline) and the like. A single or a plurality of nonionic polymers may be added.
The amount of the dispersant added may be, for example, 0.2 parts by mass or more and 3 parts by mass or less with respect to 100 parts by mass with respect to the entire components constituting the layer.

Moreover, as a dispersing agent for dispersing fluororesin particles, for example, a fluorine-based graft polymer can be mentioned.
Examples of the fluorine-based graft polymer include a copolymer of a macromonomer having a polymerizable functional group at one end of a molecular chain and a polymerizable fluorine-based monomer having a fluorinated alkyl group.
Specific examples of the fluorine-based graft polymer include macromers, polymers such as acrylates, methacrylates, and styrene compounds or copolymers thereof, and fluorine-based monomers such as perfluoroalkylethyl methacrylate and perfluoro. Examples include graft copolymers with alkyl methacrylate and the like.
The polymerization ratio between the macromonomer and the polymerizable fluorine-based monomer is, for example, 10% by mass to 50% by mass (preferably 10% by mass to 40% by mass, more preferably 10% by mass as the fluorine content in the fluorine-based graft polymer). It is preferable that the polymerization ratio be from mass% to 30 mass%.
The molecular weight of the fluorine-based graft polymer is, for example, from 5,000 to 20,000 in terms of number average molecular weight, preferably from 5,000 to 17,500, more preferably from 5,000 to 12,000.
The amount of the fluorine-based graft polymer is, for example, preferably 0.1 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass with respect to the entire components constituting the layer.

Next, it coats on the membrane | film | coat used as the base material layer in which the coating liquid for outermost layer formation was formed, and forms the coating film of the coating liquid for outermost layer formation.
The method for applying the coating solution to the cylindrical mold is not particularly limited, and is the same as the method for applying the coating solution for forming the base layer.

  Next, the coating film of the coating liquid for forming the outermost layer is dried to form a film (a layered mixture of thermoplastic polyimide resin particles, fluororesin particles, and carbon black) that becomes the outermost layer.

Next, a heat treatment is performed on the coating that becomes the base layer 12 and the outermost layer 11.
This heat treatment is performed under conditions (temperature / time) in which the polyamic acid of the film to be the base layer 12 is imidized and conditions (temperature / time) in which the polyimide resin particles of the film to be the outermost layer 11 are melted or softened. Do. Usually, if the polyamic acid of the coating film used as the base material layer is subjected to an imidization reaction, the polyimide resin particles of the coating film serving as the outermost layer are melted or softened.
And after performing this heat processing, a membrane | film | coat is extracted from a core. Thereby, the endless belt 10 which is a laminated body of the base material layer 12 and the outermost layer 11 is obtained.

  Here, as heating conditions for imidization, for example, 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, an imidization reaction takes place. 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.

  In addition, from the viewpoint of adhesion between the base material layer 12 and the outermost layer 11, a heat treatment in which the polyamic acid of the coating to be the base material layer 12 is imidized and the polyimide resin particles of the coating to be the outermost layer 11 are melted or It is preferable that the heat treatment for softening is performed at the same time. However, after forming the base material layer 12 by performing the heat treatment (firing) for imidizing the film to be the base material layer 12, the outermost layer forming coating solution May be applied to form the outermost layer 11.

The endless belt 10 according to the present embodiment described above is a laminate having a two-layer configuration of a base material layer 12 and an outermost layer 11, and an embodiment in which a polyimide resin layer containing fluororesin particles is applied as the outermost layer 11 is described. However, the present invention is not limited to this, and a single layer configuration of a polyimide resin layer containing fluororesin particles or a laminate of two or more layers having a polyimide resin layer containing fluororesin particles may be used. Specifically, for example, as shown in FIG. 3, the innermost layer 13 is provided on the inner peripheral surface of the base material layer 12, and a polyimide resin layer containing fluororesin particles is applied as the innermost layer 13 (or the outermost layer). 11 is not provided, and the innermost layer 13 is provided on the inner peripheral surface of the base material layer 12).
Further, the base material layer 12 may be a plurality of layers, and an intermediate layer (for example, the endless belt 10 is electromagnetically heated by heating between the base material layer 12 and the outermost layer 11 and between the base material layer 12 and the innermost layer 13. In the case of application as a heating belt, a form provided with a metal heating layer or the like may be used.

(Cylindrical molded unit)
FIG. 5 is a schematic perspective view showing the cylindrical molded body unit according to the present embodiment.
As shown in FIG. 5, the cylindrical molded body unit 130 (hereinafter referred to as an endless belt unit) according to the present embodiment includes the endless belt 10 according to the present embodiment. For example, the endless belt 10 is opposed to the endless belt 10. The drive roll 131 and the driven roll 132 arranged in this manner are stretched in a tensioned state (hereinafter sometimes referred to as “stretching”).
Here, in the case where the endless belt 10 is applied as an intermediate transfer member, the endless belt unit 130 according to the present embodiment uses the endless belt 10 as a roll for stretching the endless belt 10 to transfer the toner image on the surface of the photoreceptor (image holding member). A roll for primary transfer onto 10 and a roll for secondary transfer of the toner image transferred onto endless belt 10 onto a recording medium are arranged.
The number of rolls around which the endless belt 10 is stretched is not limited, and may be arranged according to the usage mode. The endless belt unit 130 having such a configuration is used by being incorporated in the apparatus, and rotates in a state where the endless belt 10 is stretched along with the rotation of the drive roll 131 and the driven roll 132.

(Image forming device member)
The endless belt according to this embodiment can be used as a member for an image forming apparatus (an image forming member according to this embodiment).
Examples of the member for the image forming apparatus include an intermediate transfer member (intermediate transfer belt), a recording medium conveyance transfer member (recording medium conveyance belt), a recording medium conveyance member (recording medium conveyance belt), and a fixing member (fixing belt: heating belt). And a pressure belt).
The endless belt according to the present embodiment includes, for example, a conveyance belt, a drive belt, a laminate belt, an electric insulating material, a pipe covering material, an electromagnetic wave insulating material, a heat source insulator, and an electromagnetic wave absorbing film, in addition to the image forming apparatus member. Etc. can also be used.

(Image forming device)
The image forming apparatus according to the present embodiment includes an image forming apparatus member (an image forming member according to the present embodiment) configured by an endless belt according to the present embodiment.
For example, the image forming apparatus according to the present embodiment includes an intermediate transfer member (intermediate transfer belt), a recording medium conveyance transfer member (recording medium conveyance belt), a recording medium conveyance member (recording medium conveyance belt), and a fixing member (fixing belt: An endless belt 10 according to this embodiment is provided as a member for an image forming apparatus such as a heating belt or a pressure belt.

  Examples of the image forming apparatus according to the present embodiment include an electrophotographic image forming apparatus such as an electrophotographic copying machine, a laser beam printer, a facsimile machine, and a composite apparatus thereof. A plurality of monochromatic image forming apparatuses that contain only a single color toner, a color image forming apparatus that sequentially repeats primary transfer of a toner image held on an image holding body to an intermediate transfer body, and a developing device for each color Examples thereof include a tandem type color image forming apparatus in which an image carrier is arranged in series on an intermediate transfer member.

  As a specific configuration of the image forming apparatus of the present embodiment, for example, an image carrier, a charging unit that charges the surface of the image carrier, an exposure unit that exposes the surface of the image carrier to form an electrostatic latent image, and The electrostatic latent image formed on the surface of the image carrier is developed with a developer to form a toner image, the transfer unit for transferring the toner image formed on the surface of the image carrier to a recording medium, and the recording Examples include a fixing unit that fixes the toner image transferred to the surface of the medium, and a fixing unit. If necessary, other known units may be further included.

  In the image forming apparatus according to the present embodiment, for example, the transfer unit is transferred to the intermediate transfer member and the primary transfer unit that primarily transfers the toner image formed on the intermediate transfer member and the image holding member to the intermediate transfer member. And a secondary transfer unit that secondary-transfers the toner image to a recording medium, and the intermediate transfer member includes the endless belt 10 according to the present embodiment.

  Further, as the image forming apparatus according to the present embodiment, for example, a recording medium conveyance transfer member (recording medium conveyance transfer belt) for conveying a recording medium by a transfer unit and a toner image formed on an image carrier are recorded on the recording medium. And a transfer means for transferring to the recording medium conveyed by the conveying transfer member, and the recording medium transfer body includes the endless belt according to the present embodiment.

  In addition, the image forming apparatus according to the present embodiment includes, for example, at least a pair of fixing members arranged so as to be pressed against each other as a fixing unit, and at least one of the pair of fixing members (fixing). Examples of the belt include a configuration including the endless belt according to the present embodiment as a heating belt or a pressure belt.

  In addition, the image forming apparatus according to the present embodiment includes, for example, a recording medium conveying member disposed in a path for conveying the recording medium from the recording medium storage container to the outside of the apparatus through the image forming unit. A configuration including the endless belt according to the present embodiment is also included.

Hereinafter, a specific example of the image forming apparatus of the present embodiment will be described in more detail with reference to the drawings.
In the specific examples shown below, the fixing unit includes a pair of fixing rolls. However, at least one fixing roll is replaced with a fixing belt, and the endless belt according to this embodiment is used as the fixing belt. It may be provided with a belt.

  FIG. 6 is a schematic configuration diagram illustrating the image forming apparatus according to the present embodiment. This image forming apparatus uses the endless belt according to this embodiment as an intermediate transfer member (intermediate transfer belt).

  An image forming apparatus 100 shown in FIG. 6 includes photoconductors (an example of an image carrier) 101Y, 101M, 101C, and 101BK, and a known electrophotographic process (on the surface thereof) as it rotates in the direction of arrow A. An electrostatic latent image corresponding to the image information is formed by a not-shown image (note that the charging device, the exposure device, the cleaning device, etc. are not shown in FIG. 6).

Around the photoreceptors 101Y, 101M, 101C, and 101BK, developing devices 105 to 108 corresponding to the respective colors of yellow (Y), magenta (M), cyan (C), and black (BK) are arranged. The electrostatic latent images formed on the photoreceptors 101Y, 101M, 101C, and 101BK are developed by the developing devices 105 to 108 to form toner images.
Therefore, for example, the electrostatic latent image written on the photoreceptor 101Y corresponds to yellow image information, and this electrostatic latent image is developed by the developing device 105 containing yellow (Y) toner, and is exposed to light. A yellow toner image is formed on the body 101Y.

  The intermediate transfer belt 102 is a belt-like intermediate transfer belt disposed so as to be in contact with the surfaces of the photoconductors 101Y, 101M, 101C, and 101BK, and an arrow is applied while being tensioned by the back roll 117 and the support rolls 118 to 119. Rotate in the direction of line B.

  The unfixed toner images formed on the photoconductors 101Y, 101M, 101C, and 101BK are sequentially transferred to the photoconductors 101Y, 101M at the respective primary transfer positions where the photoconductors 101Y, 101M, 101C, and 101BK are in contact with the intermediate transfer belt 102. , 101C and 101BK, the toner images of the respective colors are superimposed and transferred onto the surface of the intermediate transfer belt 102.

  In this primary transfer position, the pre-transfer contact area is charged by the shielding members 121 to 124 for suppressing the transfer electric field from acting on unnecessary areas of the intermediate transfer belt 102 on the back side of the intermediate transfer belt 102. Corona discharge devices are disposed as the primary transfer devices 109 to 112 which are prevented, and by applying a voltage having a polarity opposite to the charging polarity of the toner to the charging devices 109 to 112, the photosensitive members 101Y, 101M, 101C and 101BK are provided. The upper unfixed toner image is electrostatically transferred to the outer peripheral surface of the intermediate transfer belt 102. The primary transfer devices 109 to 112 are not limited to the corona discharger as long as they use an electrostatic force, and may be a roll or a brush to which a voltage is applied.

  The unfixed toner image primarily transferred to the intermediate transfer belt 102 in this way is conveyed to a secondary transfer position facing the conveyance path of the recording medium 103 as the intermediate transfer belt 102 rotates. At the secondary transfer position, a secondary transfer roll 120 and a back roll 117 in contact with the back side of the intermediate transfer belt 102 are disposed with the intermediate transfer belt 102 interposed therebetween.

  The recording medium 103 carried out from the paper feed unit 113 by the feed roll 126 is inserted into a contact portion between the secondary transfer roll 120 and the intermediate transfer belt 102. At this time, a voltage is applied to the contact portion between the secondary transfer roll 120 and the back roll 117, and the unfixed toner image held on the intermediate transfer belt 102 is transferred to the recording medium 103 at the secondary transfer position. The

  Then, the recording medium 103 on which the unfixed toner image is transferred is peeled off from the intermediate transfer belt 102, and the heating roll 127 of the fixing device provided with the heating roll 127 and the pressure roll 128 facing each other by the conveying belt 115 is added to the heating roll 127. The unfixed toner image is fixed by being sent to the contact portion with the pressure roll 128. At this time, it is also possible to adopt an apparatus configuration of a simultaneous transfer fixing process in which the secondary transfer process and the fixing process are performed simultaneously.

  The intermediate transfer belt 102 is provided with a cleaning device 116. The cleaning device 116 is disposed so as to be able to contact and separate from the intermediate transfer belt 102 and is separated from the intermediate transfer belt 102 until the secondary transfer is performed.

  FIG. 7 is a schematic configuration diagram showing another image forming apparatus of the present embodiment. The image forming apparatus is an embodiment in which the endless belt according to the present embodiment is applied as a recording medium conveying member (recording medium conveying belt).

  An image forming apparatus 200 shown in FIG. 7 includes an image forming unit 200Y, 200M, 200C, and 200Bk including a photosensitive member, a charging device, a developing device, and a photosensitive member cleaning member, a recording medium conveyance transfer belt 206, a transfer roll 207Y, 207M, 207C, and 207Bk, a recording medium conveyance roll 208, and a fixing device 209 are provided.

  The image forming units 200Y, 200M, 200C, and 200Bk include photoconductors 201Y, 201M, 201C, and 201Bk that are image carriers that rotate in the direction of arrow A (clockwise direction). Around the photosensitive members 201Y, 201M, 201C, and 201Bk, charging devices 202Y, 202M, 202C, and 202Bk, exposure devices 203Y, 203M, 203C, and 203Bk, and color developing devices (yellow developing device 204Y, magenta developing device 204M, Cyan developing device 204C and black developing device 204Bk) and photosensitive member cleaning devices 205Y, 205M, 205C, and 205Bk are disposed, respectively.

  The four image forming units 200Y, 200M, 200C, and 200Bk are arranged in the order of the image forming units 200Bk, 200C, 200M, and 200Y in parallel with the recording medium conveyance transfer belt 206, but the image forming units 200Bk, 200Y are arranged. , 200C, 200M, etc., and the order is set according to the image forming method.

  The recording medium conveyance transfer belt 206 can be rotated at the same peripheral speed as the photoconductors 201Bk, 201C, 201M, and 201Y in the direction of arrow B (counterclockwise direction) by the support rolls 210, 211, 212, and 213. A part of the support rolls 212 and 213 located in the middle is arranged so as to be in contact with the photosensitive members 201Bk, 201C, 201M, and 201Y, respectively. The recording medium conveyance transfer belt 206 is provided with a cleaning device 214.

  The transfer rolls 207Bk, 207C, 207M, and 207Y are located inside the recording medium conveyance transfer belt 206 and at positions facing the portions where the recording medium conveyance transfer belt 206 is in contact with the photosensitive members 201Bk, 201C, 201M, and 201Y. The transfer areas are respectively arranged to transfer the toner image to the recording medium P via the photoconductors 201Bk, 201C, 201M, and 201Y and the recording medium conveyance transfer belt 206.

  The fixing device 209 is arranged so that it can be conveyed after passing through the respective transfer areas of the recording medium conveyance transfer belt 206 and the photosensitive members 201Bk, 201C, 201M, and 201Y.

  The recording medium P is conveyed to the recording medium conveyance transfer belt 206 by the recording medium conveyance roll 208.

  In the image forming unit 200Y, the photosensitive member 201Y is rotationally driven. In conjunction with this, the charging device 202Y is driven to charge the surface of the photoreceptor 201Y to a predetermined polarity and potential. Next, the photosensitive member 201Y whose surface is charged is exposed imagewise by the exposure device 203Y, and an electrostatic latent image is formed on the surface.

  Subsequently, the electrostatic latent image is developed by the yellow developing device 204Y. Then, a toner image is formed on the surface of the photoreceptor 201Y. The toner at this time may be either a one-component toner or a two-component toner, but here it is a two-component toner.

  As the toner image passes through the transfer area between the photosensitive member 201Y and the recording medium conveyance transfer belt 206, the recording medium P is electrostatically attracted to the recording medium conveyance transfer belt 206 and conveyed to the transfer area. The image is sequentially transferred onto the outer peripheral surface of the recording medium P by an electric field formed by a transfer bias applied from the roll 207Y.

  Thereafter, the toner remaining on the photoconductor 201Y is cleaned and removed by the photoconductor cleaning device 205Y. Then, the photoreceptor 201Y is subjected to the next transfer cycle.

  The above transfer cycle is similarly performed in the image forming units 200M, 200C, and 200Bk.

  The recording medium P onto which the toner image has been transferred by the transfer rolls 207Bk, 207C, 207M, and 207Y is further conveyed to the fixing device 209 and fixed. Thus, a desired image is formed on the recording medium.

  Here, the recording medium is usually a sheet-shaped recording medium (so-called paper) or a sheet-like material made of a relatively flexible material such as a recording medium (so-called OHP sheet) made of a plastic film. However, a plate-like member made of a material having a relatively high rigidity (for example, a thick plastic card) may be used as the recording medium.

  In the image forming apparatus according to the present embodiment, the electrophotographic image forming apparatus has been described. However, the image forming apparatus is not limited to this, and a known image forming apparatus other than the electrophotographic system (for example, an endless belt for paper conveyance is provided). Or an inkjet recording apparatus).

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

[Preparation Example 1: Preparation of thermoplastic polyimide resin coating solution (A-1)]
As a thermoplastic polyimide resin, AURUM melt-molded pellets manufactured by Mitsui Chemicals Co., Ltd. were pulverized at 8000 rpm using an ultracentrifugal mill ZM200 manufactured by Retsch. The volume average particle size of the thermoplastic polyimide resin particles after pulverization was 50 μm.
200 g of thermoplastic polyimide resin particles, 200 g of PTFE particles (Daikin Kasei Lubron L-2: volume average particle size 3 μm) as fluororesin particles, 80 g of carbon black (SB-4 manufactured by Degussa) as conductive material, 1 g of sodium polyphosphate The mixture was gradually added to 200 ml of ion-exchanged water and 200 ml of isopropyl alcohol, and mixed. The solution was subjected to dispersion treatment at 500 rpm × 10 minutes using a high flex disperser (manufactured by SMT Co., Ltd.) to prepare a thermoplastic polyimide resin coating solution (A-1).

[Preparation Example 2: Preparation of thermoplastic polyamideimide resin coating solution (B-1)]
As a thermoplastic polyamide-imide resin, melt-molded pellets of Sollon Advanced Polymers Torlon 4203 were pulverized at 8000 rpm using a Retsch ultracentrifugal mill ZM200. The volume average particle diameter of the thermoplastic polyimide particles after pulverization was 60 μm.
200 g of thermoplastic polyamideimide particles, 200 g of PTFE particles (Daikin Kasei Lubron L-2: volume average particle size 3 μm) as fluororesin particles, 80 g of carbon black (SB-4 manufactured by Degussa) as a conductive material, 1 g of sodium polyphosphate The mixture was gradually added to 200 ml of ion-exchanged water and 200 ml of isopropyl alcohol, and mixed. The mixture was subjected to a dispersion treatment at 500 rpm for 10 minutes using a high flex disperser (manufactured by SMT Co., Ltd.) to prepare a thermoplastic polyamideimide resin coating liquid (B-1).

[Preparation Example 3: Preparation of thermoplastic polyetherimide resin coating solution (C-1)]
As a thermoplastic polyetherimide resin, a melt molded pellet of ULTEM manufactured by GE Plastics was pulverized at 8000 rpm using an ultracentrifugal pulverizer ZM200 manufactured by Retsch. The volume average particle diameter of the pulverized thermoplastic polyetherimide particles was 40 μm.
200 g of thermoplastic polyetherimide resin particles, 200 g of PTFE particles (Daikin Kasei Lubron L-2: volume average particle size 3 μm) as a fluororesin, and 80 g of carbon black (SB-4 manufactured by Degussa) as a conductive material, sodium polyphosphate The mixture was gradually added to 200 ml of ion exchange water in which 1 g was dissolved and 200 ml of isopropyl alcohol while mixing. Using a high flex disperser, a dispersion treatment was performed at 500 rpm for 10 minutes to prepare a thermoplastic polyetherimide resin coating liquid (C-1).

[Preparation Examples 4 to 7: Preparation of coating solution for thermoplastic polyimide resin (A-3 to A-6)]
In Preparation Example 1, except that the polyimide resin type, fluororesin type, carbon black, and the blending amount (blending ratio) thereof were changed in accordance with Tables 1 and 2, the same process as in Preparation Example 1 was performed to obtain a thermoplastic polyimide resin. Coating solutions (A-3 to A-6) were prepared.

[Adjustment Example 8: Adjustment of thermoplastic polyimide resin coating solution (A-2)]
As a thermoplastic polyimide resin solution, 66 g of PTFE particles (Daikin Kasei Lubron L-2: volume average particle size 3 μm) in 300 g (resin content 66 g) of polyimide varnish unidic V8004 (solid content 22 mass%) manufactured by DIC Corporation And 26.6 g of carbon black (SB-4 manufactured by Degussa) as a conductive material were gradually added and mixed. The solution was subjected to dispersion treatment at 500 rpm × 10 minutes using a high flex disperser (manufactured by SMT Co., Ltd.) to prepare a thermoplastic polyimide resin coating solution (A-2).

[Adjustment Example 9: Adjustment of thermoplastic polyamideimide resin coating solution (B-2)]
PTFE particles (Daikin Kasei Lubron L-2: volume) as fluororesin particles in 500 g (resin content 70 g) of polyamideimide varnish Viromax HR16NN (solid content 14 mass%) manufactured by Toyobo Co., Ltd. as a thermoplastic polyamideimide resin solution The mixture was mixed while gradually adding 70 g of an average particle diameter of 3 μm and 28 g of carbon black (SB-4 manufactured by Degussa) as a conductive material. The solution was subjected to a dispersion treatment at 500 rpm × 10 minutes using a high flex disperser (manufactured by SMT Co., Ltd.) to prepare a thermoplastic polyimide resin coating solution (B-2).

[Preparation Examples 10 to 13: Preparation of thermoplastic polyimide resin coating solutions (A-7 to A-10)]
In Preparation Example 1, except that the polyimide resin type, fluororesin type, carbon black, and the blending amount (blending ratio) thereof were changed in accordance with Tables 1 and 2, the same process as in Preparation Example 1 was performed to obtain a thermoplastic polyimide resin. Coating solutions (A-7 to A-10) were prepared.

[Adjustment Example 14: Thermosetting polyimide resin coating solution (G-1)]
As thermosetting polyimide resin (polyamic acid solution to be a precursor solution thereof), 1000 g (resin solid content 400 g) of polyimide varnish (trade name; U-varnish-A: solid content 20 mass%) manufactured by Ube Industries, Ltd. 120 g of carbon black was gradually added and mixed. The solution was subjected to a dispersion treatment at 500 rpm × 10 minutes using a high flex disperser to prepare a thermosetting polyimide resin coating solution (G-1).

[Adjustment Example 15: Thermosetting polyimide resin coating solution (G-2)]
As thermosetting polyimide resin (polyamic acid solution to be a precursor solution thereof), 1000 g (resin solid content 400 g) of polyimide varnish (trade name; U-varnish-A: solid content 20 mass%) manufactured by Ube Industries, Ltd. As a fluororesin, 200 g of PTFE particles (Daikin Kasei Lubron L-2: volume average particle size 3 μm) and 40 g of carbon black were gradually added and mixed. The solution was subjected to a dispersion treatment at 500 rpm for 10 minutes using a high flex disperser to prepare a thermosetting polyimide resin coating solution (G-2).

[Example 1: Production of endless belt (ST-1)]
A cylindrical mold made of SUS material having an outer diameter of 90 mm and a length of 450 mm was prepared, and a silicone release agent was applied to the outer surface and subjected to a drying treatment (release agent treatment). While rotating the cylindrical mold subjected to the release agent treatment in the circumferential direction at a speed of 10 rpm, the thermosetting polyimide resin coating liquid (G- While discharging 1) from a 1.0 mm diameter dispenser, application was performed while pressing with a uniform pressure with a metal blade placed on the mold. The dispenser unit was moved in the axial direction of the cylindrical mold at a speed of 100 mm / min to apply the coating solution on the cylindrical mold in a spiral manner. After coating, the blade was released and the cylindrical mold was kept rotating for 2 minutes for leveling.
Thereafter, the cylindrical mold on which the coating film was formed was subjected to a drying treatment for 30 minutes while rotating at 10 rpm in an air atmosphere at 150 ° C. in a drying furnace. After drying, the solvent was volatilized from the coating film, so that the coating film was changed to a polyamic acid film having a self-supporting property (a film serving as a base material layer).

After the drying treatment, a thermoplastic polyimide resin coating as an outermost layer forming coating liquid is applied from the end of the cylindrical mold while rotating the cylindrical mold on which the polyamic acid film is formed at a speed of 10 rpm in the circumferential direction. The liquid (A-1) was applied while being pressed with a uniform pressure by a metal blade placed on a mold while being discharged from a dispenser having a caliber of 1.0 mm. The dispenser unit was moved in the axial direction of the cylindrical mold at a speed of 100 mm / min to apply the coating solution on the cylindrical mold in a spiral manner. After coating, the blade was released and the cylindrical mold was kept rotating for 2 minutes for leveling.
Then, the cylindrical metal mold | die which formed the said coating film on the film | membrane of polyamic acid performed the drying process for 30 minutes, rotating at 10 rpm in a 150 degreeC air atmosphere in a drying furnace. This formed the film (layered mixture of each particle) used as the outermost layer on the polyamic acid film.

After drying, heat treatment is performed at 250 ° C. for 30 minutes in a clean oven, the solvent is distilled off, and the imidation reaction of the film (polyamic acid film) that becomes the base material layer is completed and the film that becomes the outermost layer The thermoplastic polyimide resin particles inside were melted or softened.
Thereafter, the mold was set to 25 ° C., the coating resin was removed from the mold, and the desired endless belt (ST-1) in which the base material layer and the outermost layer were laminated was obtained.

[Examples 2-7, Comparative Examples 1-7: Production of Endless Belts (ST-2) to (ST-7), (RT-1) (RE-2) to (RE-7)]
Endless belts (ST-2) to (ST-7) in the same manner as in Example 1 except that the base layer forming coating solution and the outermost layer forming coating solution to be used were changed according to Tables 3 to 4. (RT-1) (RE-2) to (RE-7) were obtained.

[Evaluation]
The following evaluation was performed on the endless belt obtained in each example. The results are shown in Tables 3-4.

(Surface properties)
The surface of the obtained endless belt was visually observed for the presence or absence of voids and the presence or absence of film shrinkage. Each evaluation was evaluated according to the following criteria.
-Void-
○: No voids are generated on the surface Δ: 1-10 voids of 1 mm or less are generated on the surface ×: 11 or more voids of 1 mm or less are generated on the surface, or 1 mm or more voids are generated -Membrane shrinkage-
○: No film shrinkage on the surface ×: Film shrinkage on the surface

(Film thickness)
Ten test pieces were randomly cut from the obtained endless belt, and the film thickness was measured using a film thickness meter. With an endless belt, the film thickness of the end where the surface layer was not applied to the surface of the base material layer was defined as the base material layer film thickness, and the film thickness of the portion where the outermost layer was formed on the base material layer surface was defined as the total film thickness. . The film thickness of the outermost layer was calculated by subtracting the base material layer film thickness from the total film thickness.

(Abrasion resistance test)
The abrasion resistance test was determined by the following method. The produced endless belt was cut into about 100 mm square, and the small piece was fixed to the glass plate with an instantaneous adhesive. This sample was set on a scratch tester CSR-101 (manufactured by Reska Co., Ltd.) rotary sample table. A nylon cloth was placed on a 10φ probe, and the sample surface was rubbed while rotating at 200 rpm with a load of 2 kg. The amount of wear after 2000 rotations was evaluated by a film thickness difference from an untested part by a stylus type film thickness meter Alphastep 500 KLA Tencor. Although the film thickness after the test was reduced by 5 μm, it was a level with no problem in use.

(Folding resistance)
Ten pieces cut out from the obtained endless belt were repeatedly bent 100 times with a MIT tester under the conditions of a tensile load of 1.0 kg and a refraction angle of 135 °, and evaluated by the number of sheets in which the outermost layer was broken. .

(Print quality)
Using a modified DocuCenterColor2220 manufactured by Fuji Xerox Co., Ltd. (process speed: 250 mm / sec, modified to primary transfer current: 35 μA), the obtained endless belt was mounted as an intermediate transfer belt, and high temperature and high humidity (28 ° C., 85% RH) ) And low-temperature and low-humidity (10 ° C., 15% RH) color toner (cyan toner, magenta toner) such as DocuCentreColor 2220 manufactured by Fuji Xerox Co., and 50% halftone of Cyan and Magenta is output to C2 paper manufactured by Fuji Xerox Co., Ltd. According to the following criteria, density unevenness and speckle defects were visually evaluated according to the following criteria.

-Density unevenness-
The print portion of the tenth print sample is divided into 3 × 3 = 9 equal parts, and each chromaticity is measured using a chromaticity meter CR-210 (manufactured by Minolta Co., Ltd.). The color difference ΔE, which is the difference from the above, was obtained. “O” or higher was accepted.
A: Color difference ΔE is less than 0.3 (density unevenness is not confirmed).
○: Color difference ΔE is 0.3 or more and less than 0.5.
Δ: Color difference ΔE is 0.5 or more and less than 1.0.
X: Color difference ΔE is 1.0 or more.

-Spot defect-
Spots in the printed part of the tenth printed sample were visually observed and evaluated according to the following criteria. “O” or higher was accepted.
A: Less than 10 spots with a size of less than 0.5 mm.
A: 10 or more and less than 50 spots with a size of less than 0.5 mm were generated.
Δ: 50 or more and less than 100 spots with a size of less than 0.5 mm were generated. Alternatively, less than 50 spots having a size of 0.5 mm or more and less than 1.0 mm were generated, and spots having a size of 1.0 mm or more were not generated.
X: 100 or more spots having a size of less than 0.5 mm were generated. Alternatively, 50 or more spots having a size of 0.5 mm or more and less than 1.0 mm were generated. Alternatively, one or more spots having a size of 1.0 mm or more occurred.

(Belt properties after paper passing test)
As the belt properties after the paper passing test on the obtained endless belt, whether or not the belt is damaged after the paper passing test is measured after 1000 paper passing tests (after 30% halftone image formation) and before the paper passing. And compared.

  From the above evaluation results, compared to the comparative example, this example showed that good results were obtained for the evaluation of the surface properties, abrasion resistance test, folding resistance, print image quality, and belt properties after passing through the paper. As can be seen, good results were obtained.

In addition, the detail of the code | symbol of the polyimide-type resin kind in Tables 1-3 and a fluororesin kind is as follows.
-Polyimide resin-
PI-1: AURUM PL450C melt-molded pellets manufactured by Mitsui Chemicals (thermoplastic polyimide resin, melt temperature 388 ° C .: mold temperature 390-420 ° C.)
PI-2: DIC polyimide varnish unidic V8004 (thermoplastic polyimide resin)
PI-3: Ube Industries' polyimide varnish (trade name; U-varnish-A: solid content 20%) (thermosetting polyimide resin)
PAI-1: Polyamideimide varnish Viromax HR16NN (thermoplastic polyamideimide resin) manufactured by Toyobo Co., Ltd.
PAI-2: Torlon 4205 (thermoplastic polyamideimide resin, melting temperature 290 ° C .: molding temperature 300-370 ° C.)
PEI-1: ULTEM1000 (thermoplastic polyetherimide resin, melting temperature 350-400 ° C.) manufactured by GE Plastics
-Fluororesin-
・ PTFE-1: Lubron L-2

10 Cylindrical compact (endless belt)
DESCRIPTION OF SYMBOLS 11 Outermost layer 12 Base material layer 12 Innermost layer 100 Image forming apparatus 101Y, 101M, 101C, 101BK Photoconductor 102 Intermediate transfer belt 105-108 Developer 200 Image forming apparatus 200Y, 200M, 200C, 200Bk Image forming unit 206 Recording medium conveyance Transfer belt

Claims (7)

  A layered mixture comprising a thermoplastic polyimide resin particle having a volume average particle size of 40 μm or more and 2 mm or less, excluding polyetherimide resin particles, and a fluororesin particle having a volume average particle size of 0.5 μm or more and 20 μm or less. A molten layer or a softened layer of the polyimide resin particles, or a thermoplastic polyimide resin particle having a volume average particle diameter of 40 μm or more and 2 mm or less, and a fluorine resin particle having a volume average particle diameter of 0.5 μm or more and 3 μm or less. A cylindrical molded body having a molten layer or a softened layer of the polyimide-based resin particles in a layered mixture containing. The cylindrical molded body is composed of a laminate of two or more layers,
The cylindrical molded body according to claim 1, which has a molten layer or a softened layer of the polyimide resin particles as an outermost layer. The cylindrical molded body is composed of a laminate of two or more layers,
The cylindrical molded body according to claim 1 or 2, wherein the layer in contact with the melted layer or the softened layer of the polyimide resin particles is a layer configured to contain a polyimide resin.   The cylindrical molded body according to any one of claims 1 to 3, wherein the molten layer or the softened layer of the polyimide resin particles contains a conductive material.   5. A cylindrical molded body according to claim 1, and a plurality of rolls that span the cylindrical molded body in a tensioned state, and is attached to and detached from the image forming apparatus. Cylindrical molded unit.   The member for image forming apparatuses comprised with the cylindrical molded object of any one of Claims 1-4.   An image forming apparatus comprising the member for an image forming apparatus according to claim 6.