JP2007058037A - Transfer belt and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transfer belt and an image forming apparatus that are superior in both the low friction properties and wear resistance. <P>SOLUTION: The transfer belt used in the image forming apparatus is formed of a first resin containing crosslinked polytetrafluoroethylene polymer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a transfer belt used in an image forming apparatus using an electrophotographic system such as a copying machine or a printer, and an image forming apparatus including the transfer belt.

  As an image forming apparatus using an electrophotographic system, for example, a transfer type color image forming apparatus using a transfer belt is known. In such an image forming apparatus, the transfer belt is placed between a plurality of support rolls so that the transfer belt is rotated in contact with a precharged image carrier on which a toner image is formed by an electrophotographic process or the like. It is arranged in a stretched manner. Each of the toner images of a plurality of colors formed on the image carrier is primarily transferred so as to be superimposed on the same position of the transfer belt, and then secondarily transferred from the transfer belt to the recording medium. The multicolor toner image secondarily transferred onto the recording medium is then fixed by a fixing device, and a color image is formed on the recording medium. The primary transfer is performed by applying a voltage through the transfer belt so that the charged toner carried on the image carrier that has been charged in advance is transferred to the transfer belt side.

For these transfer belts, wear resistance is improved to suppress deterioration of transportability and transferability due to wear, low friction is achieved to ensure driveability due to low friction, and toner, paper dust, etc. In order to satisfy such characteristics, various materials are used.
Specifically, Patent Document 1 discloses a technique using a belt containing hydrophobized oxide particles, and Patent Document 2 discloses that a fluororesin powder is dispersed in a polyimide resin tubular layer. A technique using a belt, Patent Document 3, for example, discloses a belt using a fluoropolymer composition containing a filler surface-treated with a fluoroalkyl group-containing compound.

JP-A-11-174706 JP-A-5-163360 JP 2000-281855 A

In the technique of Patent Document 1, the toner particles fixed on the surface can be easily peeled by providing a particle layer on the surface of the transfer belt, and contamination of the transfer belt surface by the toner can be suppressed. There is a problem that the abrasion resistance is lowered due to the peeling of the surface layer due to. Moreover, according to the technique of patent document 2, generation | occurrence | production of an abrasion powder can be suppressed by disperse | distributing a fluororesin powder in the polyimide resin which is excellent in heat resistance and mechanical strength, but is inferior in abrasion resistance. However, there has been a problem in that self-breaking of the fluororesin powder occurs when used. According to the technique of Patent Document 3, although it is possible to suppress a decrease in resistance value due to a change with time by containing a surface-treated filler, low friction property is obtained by utilizing brittleness caused by containing a filler. Therefore, there is a problem that the wear resistance is inferior.
As described above, it has been difficult for the conventional technology to achieve both improvement of wear resistance and prevention of surface contamination.

  The present invention has been made in view of these circumstances, and an object of the present invention is to provide a transfer belt and an image forming apparatus excellent in both improvement of wear resistance and prevention of surface contamination.

The above problem is solved by the following means. That is, the present invention
(1) A transfer belt used in an image forming apparatus, wherein the transfer belt is formed from a first resin containing a crosslinked polytetrafluoroethylene polymer.
The first resin is made of an imide resin, and can contain a conductive agent in the first resin. As the conductive agent, it is preferable to use carbon black.
The content of the crosslinked polytetrafluoroethylene with respect to the first resin is 1.0 part by mass or more and 20.0 parts by mass or less with respect to 100 parts by mass of the first resin.
The volume average primary particle size of the crosslinked polytetrafluoroethylene polymer is 1.0 μm or more and 50 μm or less.
It is essential that the thickness of the transfer belt is in the range of 30 μm to 100 μm.
The transfer belt can be provided with meandering prevention rib guides along at least one side edge in the width direction of the transfer belt body.
The meandering prevention rib guide is formed from a second resin containing a cross-linked tetrafluoroethylene polymer.
The content of the crosslinked tetrafluoroethylene polymer relative to the second resin is 1.0 part by mass or more and 20.0 parts by mass or less with respect to 100 parts by mass of the second resin.
The second resin is made of an elastomer and is preferably urethane rubber or silicone rubber.
(2) An image forming apparatus including the transfer belt according to (1).

  According to the transfer belt and the image forming apparatus provided with the transfer belt of the present invention, since the transfer belt is formed from the first resin containing the crosslinked polytetrafluoroethylene polymer, the wear resistance is improved and the surface is contaminated. Therefore, it is possible to provide a transfer belt and an image forming apparatus that are excellent in both of prevention of image formation.

<Transfer belt>
Hereinafter, the transfer belt of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a schematic diagram of a transfer belt according to the present invention.
As shown in FIG. 1, the transfer belt 10 according to the present invention includes a transfer belt main body 12 and a meandering prevention rib guide 14. The transfer belt main body 12 corresponds to the transfer belt of the present invention.
The meandering prevention rib guide 14 is bonded along a side edge of at least one side of the transfer belt body 12 via an adhesive portion (not shown). For example, the adhesive portion is a solid that does not have adhesive strength and adhesive strength at normal temperature, but is composed of an adhesive that melts by heating and exhibits adhesive strength when cooled and solidified.
The transfer belt 10 of the present invention is suitably used for a photosensitive device, an intermediate transfer device, a transfer separation device, a transport device, a charging device, a developing device, etc. in an electrophotographic copying machine, a laser printer or the like. The material, shape, size, and the like of the transfer belt main body 12 constituting the transfer belt of the present invention are appropriately set according to the use, function, and the like of the transfer belt 10.

Next, materials and manufacturing methods constituting the transfer belt 10 of the present invention will be sequentially described.
-Transfer belt body-
The transfer belt main body 12 of the present invention is formed of a first resin containing a crosslinked tetrafluoroethylene polymer.
By containing a cross-linked tetrafluoroethylene polymer in the first resin, a small molecular weight (that is, a short polymer chain) when a non-cross-linked tetrafluoroethylene polymer is contained in the first resin. And the mechanical brittleness caused by having no cross-linked structure, and the polytetrafluoroethylene polymer having a cross-linked structure is entangled between the polymer chains of the first resin. Friction resistance, wear resistance, and creep characteristics, which are characteristics of coalescence, can be improved.
As a result, it is possible to prevent toner contamination and paper dust fixation by having a surface layer with low surface energy, and to provide a transfer belt excellent in both wear resistance and prevention of surface contamination. be able to.
In addition, uncrosslinked tetrafluoroethylene polymers are prone to degradation against electrical stress, but the cross-linked tetrafluoroethylene polymer has a strong bonding force. Can be prevented from degrading against mechanical stress.

―First resin―
Although it does not specifically limit as 1st resin containing a crosslinked tetrafluoroethylene polymer, Polyimide-type resin, polyamideimide-type resin, polyester-type resin, polyamide-type resin, fluorine-type resin, etc. are used. Among these resins, it is preferable to use a polyimide resin as the first resin because it has higher mechanical strength than other resins.
That is, by including a cross-linked tetrafluoroethylene polymer in a polyimide resin with high mechanical strength, a polytetrafluoroethylene polymer having a cross-linked structure is entangled between the polymer chains of the polyimide resin, and the transfer belt body In addition to the mechanical strength of the polyimide resin, it is possible to improve body friction, wear resistance, and creep characteristics, which are characteristics of the crosslinked tetrafluoroethylene polymer.
As a result, it is possible to prevent toner contamination by forming a layer having a low surface energy and to prevent paper dust from sticking, improve the abrasion resistance and durability as a transfer belt, and further improve the image quality by surface uniformity. Can be demonstrated.

-Polyimide resin-
The polyimide resin used as the first resin of the present invention is not particularly limited, but includes a tetracarboxylic dianhydride having a wholly aromatic skeleton that is a tetracarboxylic acid residue and a diphenyl ether skeleton that is a diamine residue. The main component is preferably a polymer formed by imide bonding with a diamine component, that is, a polyimide resin having an ether skeleton in the diamine residue.
By using as a main component a polyimide resin having an ether skeleton in this diamine residue, flexibility can be imparted to a material mainly composed of a polyimide tree, and quantitatively, the surface microhardness is 30 It is also possible to set it below the degree.

  Examples of the diamine component having the diphenyl ether skeleton include 4,4′-diaminodiphenyl ether, 3,3′-diaminodiphenyl ether, and compounds obtained by substituting these aromatic rings with a lower alkyl group. Diaminodiphenyl ether is preferred.

  Examples of the tetracarboxylic dianhydride having a wholly aromatic skeleton include pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,3,3 ′, 4 ′. -Biphenyltetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalene Examples thereof include tetracarboxylic dianhydrides or compounds obtained by substituting these aromatic rings with lower alkyl groups. Among these, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride is particularly preferable.

  Moreover, as a polyimide-type resin, the polymer formed by the imide bond of the tetracarboxylic dianhydride which has a wholly aromatic skeleton, and the diamine component which has a diphenyl ether skeleton can be used. In addition, if the polymer has a surface layer having a surface microhardness within a range of 30 degrees or less, a tetracarboxylic dianhydride having a wholly aromatic skeleton, which is preferable as a polyimide resin, and p-phenylene It is also preferred that a polymer formed by imide bonding with a diamine component having a skeleton is used in combination.

  Specific examples of polyimide resins formed by imide bonding of the tetracarboxylic dianhydride having a wholly aromatic skeleton and a diamine component having a diphenyl ether skeleton include 3,3 ′, 4,4′-biphenyltetracarboxylic A polyimide resin formed by imide bonding of acid dianhydride (BPDA) and 4,4′-diaminodiphenyl ether (DDE) is exemplified.

  In addition, as a polyimide resin, a polymer formed by imide bonding of a tetracarboxylic dianhydride having a wholly aromatic skeleton that is a tetracarboxylic acid residue and a diamine component having a p-phenylene skeleton that is a diamine residue , May be the main component. By using as a main component a polymer formed by imide bonding of a tetracarboxylic dianhydride having a wholly aromatic skeleton and a diamine component having a p-phenylene skeleton, it becomes easy to ensure the rigidity of the transfer belt. The Young's modulus of the transfer belt can be 4000 MPa or more.

Examples of the diamine component having the p-phenylene skeleton include compounds in which p-phenylenediamine or an aromatic ring thereof is substituted with a lower alkyl group or the like.
In addition, as long as the polyimide resin is within a range in which the Young's modulus of the transfer belt can be maintained at 4000 MPa or more, the tetracarboxylic dianhydride having the wholly aromatic skeleton and the diamine component having the p-phenylene skeleton are imides. A polymer formed by bonding a tetracarboxylic dianhydride having the wholly aromatic skeleton described above with a diamine component having a diphenyl ether skeleton, which contains a polymer formed by bonding as a main component, is included. Is also preferable.
Specific examples of polyimide resins formed by imide bonding of the tetracarboxylic dianhydride having a wholly aromatic skeleton and a diamine component having a p-phenylene skeleton include 3,3 ′, 4,4′-biphenyl. Examples thereof include polyimide resins formed by imide bonding of tetracarboxylic dianhydride (BPDA) and p-phenylenediamine (PDA).

In the transfer belt of the present invention, as a polyimide resin, a polymer formed by imide bonding of a tetracarboxylic dianhydride having a wholly aromatic skeleton and 4,4′-diaminophenyl ether, a wholly aromatic skeleton A polymer formed by imide bonding of tetracarboxylic dianhydride having p-phenylenediamine and a polymer formed by imide bonding of biphenyltetracarboxylic dianhydride and 4,4′-diaminophenyl ether It is preferable that
Examples of the polymer formed by imide bonding of tetracarboxylic dianhydride having a wholly aromatic skeleton and 4,4′-diaminophenyl ether include Uimide MX (manufactured by Unitika), tetracarboxylic having a wholly aromatic skeleton. As a polymer formed by imide bonding of acid dianhydride and p-phenylenediamine, for example, Uimide TX (manufactured by Unitika), or biphenyltetracarboxylic dianhydride and 4,4′-diaminophenyl ether are used. As a polymer formed by imide bonding, for example, Uimide KX (manufactured by Unitika) can be preferably used.

-Crosslinked tetrafluoroethylene polymer-
The first resin used in the transfer belt body 12 of the present invention contains a crosslinked tetrafluoroethylene polymer.
The content of the crosslinked polytetrafluoroethylene polymer must be in the range of 1.0 part by weight or more and less than 20.0 parts by weight with respect to 100 parts by weight of the first resin, preferably 2 parts by weight. Part by mass to 15 parts by mass, more preferably 5 parts by mass to less than 10 parts by mass.
When the content of the crosslinked tetrafluoroethylene polymer with respect to 100 parts by mass of the first resin is less than 1.0 part by mass, surface toner contamination occurs, and when it is 20.0 parts by mass or more, the surface unevenness increases. There is a problem that the flatness is impaired.

  The cross-linked tetrafluoroethylene polymer may be used as a powder (spherical shape). In this case, the volume average primary particle size of the crosslinked tetrafluoroethylene polymer is

It needs to be in the range of 1 μm or more and 50 μm or less, preferably in the range of 1.0 μm or more and 20.0 μm or less, and particularly preferably in the range of 1 μm or more and 10 μm or less.
If the volume average primary particle size exceeds 50 μm, irregularities are likely to occur on the surface, which may cause problems on the image. Further, if the volume average primary particle size is less than 1 μm, there may be a problem of significant cost increase in production.

  The cross-linked tetrafluoroethylene polymer is, for example, a commercially available PTFE (tetrafluoroethylene polymer) powder of 10 3 to 10 7 m 2 s −2 (1 kGy to 10 MGy) at 300 ° C. or higher in an inert atmosphere. It is possible to produce by irradiating with ionizing radiation, and pulverizing with a jet mill or the like so that the volume average particle diameter described above is obtained. Here, the inert atmosphere refers to an atmosphere mainly composed of rare gas or N 2 gas.

Heating to 300 ° C. or higher activates the molecular motion of the main chain constituting the first resin, and as a result, the intermolecular crosslinking reaction can be efficiently promoted. However, excessive heating leads to the cleavage and decomposition of the molecular main chain, so that the heating temperature is preferably 310 to 340 ° C. in order to suppress the occurrence of such a depolymerization phenomenon. .
Moreover, as ionizing radiation, an electron beam, a gamma ray, a neutron beam, an X-ray, a high energy ion, etc. are used.

  The crosslinking degree (crosslinking density, crosslinked structure, etc.) of the crosslinked tetrafluoroethylene polymer used in the present invention is preferably 85 to 99, more preferably 90 to 99.

  The degree of crosslinking, that is, the degree of crosslinking, can be evaluated based on resistance to solvents and insolubility. What was sufficiently soluble before cross-linking becomes insoluble after cross-linking according to the degree of cross-linking. For example, the weight difference after the object is immersed in a solvent at a temperature of 50 ° C. for about 10 minutes, taken out, and then the solvent is volatilized (hereinafter, this value may be referred to as “crosslinking degree”). Can be compared. As solvent resistance to a specific solvent, when it is about 80% of the original weight (crosslinking degree 80%), it cannot be said that it has a cross-linked structure without heat resistance up to 200 ° C. An insolubility of 95% (crosslinking degree 95%) or more with respect to the weight is one indication of having a crosslinked structure.

The transfer belt main body 12 may or may not have a joint as long as it is annular. It is essential that the thickness of the transfer belt body 12 be in the range of 30 μm to 100 μm, preferably in the range of 50 μm to 90 μm, more preferably in the range of 60 μm to less than 80 μm.
If the thickness of the transfer belt main body 12 is less than 30 μm, there arises a problem that the belt breaks due to insufficient tensile and tear strength, and if it is thicker than 100 μm, the rigidity becomes too strong, resulting in insufficient belt deformation followability.
The surface resistivity of the transfer belt body 12 is adjusted in the range of 1 × 10 ¹⁰ to 1 × 10 ¹⁴ Ω / □, and the volume resistivity is in the range of 1 × 10 ⁸ to 1 × 10 ¹³ Ωcm. It is preferable to be prepared. The surface resistivity can be measured in accordance with JIS K6911 using a circular electrode (for example, “HR probe” of Hiresta IP manufactured by Mitsubishi Yuka Co., Ltd.).

―Conductive agent―
The first resin can contain a conductive agent.
Examples of the conductive agent include carbon black such as ketjen black and acetylene black, metal or alloy such as graphite, carbon nanotube, aluminum, nickel and copper alloy, tin oxide, zinc oxide, potassium titanate, tin oxide-indium oxide or oxide A metal oxide such as tin-antimony oxide composite oxide, or a conductive polymer such as polyaniline, polypyrrole, polysulfone, or polyacetylene can be preferably used. These conductive agents are used alone or in combination of two or more.
These conductive agents are appropriately selected depending on the purpose of use. For example, if you want to obtain a transfer belt with small environmental fluctuations or a transfer belt with a high surface gloss, use metal oxide or carbon black. If you want to obtain a transfer belt with little resistance variation, use a conductive polymer. It is done.
As the conductive agent, it is preferable to use carbon black from the viewpoints of low cost and easy resistance adjustment, and good dispersibility.
In addition, a processing aid such as a dispersant and a lubricant can be further added to the first resin as necessary.
The content of the conductive agent is essential to be in the range of 1 to 50 parts by mass with respect to 100 parts by mass of the first resin, and in the range of 2.5 to 40 parts by mass. It is preferable that it is within a range of 5 parts by mass or more and less than 35 parts by mass.
When the content of the conductive agent is less than 1 part by mass, there is a problem of insufficient conductivity, and when it is more than 50 parts by mass, there is a problem that the belt strength is reduced.

-Meandering prevention rib guide-
When a shifting force that causes the transfer belt body 12 to move in the axial direction of the belt support roll is generated, a reaction force (stress) having the same strength against the shifting force is directly applied to the meandering prevention rib guide 14. . From the standpoint that this stress can be dispersed and absorbed to some extent by the meandering prevention rib guide 14 itself, the meandering prevention rib guide 14 is preferably a member having a JIS A hardness A60 to A90 (/ S), particularly preferably JIS A. The hardness is in the range of A60 to A80 (/ S). When the JIS A hardness is smaller than A60 (/ S), the deformation of the meandering prevention rib guide 14 is large, so that the transfer belt 10 may get on, and when the JIS A hardness is larger than A90 (/ S). In some cases, the transfer belt 10 may not follow a support roll described later. Here, the JIS A hardness is a rubber hardness defined in JIS K6253 (1997).

The meandering prevention rib guide 14 provided in the transfer belt body 12 of the present invention is formed of a second resin containing a crosslinked tetrafluoroethylene polymer.
As the material of the second resin, an elastic body having an appropriate hardness such as polyurethane resin, neoprene rubber, polyurethane rubber, silicone rubber, polyester elastomer, chloroprene rubber, nitrile rubber, or the like can be used. Among these, in consideration of electrical insulation, moisture resistance, solvent resistance, ozone resistance, heat resistance, and abrasion resistance, elastomers are preferable, and polyurethane rubber and silicone rubber are particularly preferably used.
The meandering prevention rib guide 14 is disposed at the end of the transfer belt main body 12 in the width direction, and supports a transfer belt 10 and a groove formed in a support roll (details will be described later) for driving the transfer belt 10 in a predetermined direction. By being installed so as to be fitted, the meandering of the transfer belt 10 that is transported and driven is suppressed. During the conveyance driving of the transfer belt main body 12, a resultant force between the conveyance driving direction of the transfer belt 10 and a direction perpendicular to the conveyance driving direction is applied to the meandering prevention rib guide 14. If this resultant force is transmitted to the transfer belt main body 12 without being lost, there is a problem that the transfer belt main body 12 is broken or deformed.
If an elastomer is used as the second resin, the resultant force can be lost and the resultant force can be prevented from being transmitted to the transfer belt body 12.

The content of the crosslinked polytetrafluoroethylene polymer contained in the second resin of the present invention is within the range of 1.0 part by mass or more and 20.0 parts by mass or less with respect to 100 parts by weight of the resin constituting the elastic member. It is essential that it is in the range of 2 to 15 parts by mass, more preferably in the range of 5 to 10 parts by mass.
When the content of the crosslinked polytetrafluoroethylene polymer is less than 1.0 part by mass with respect to 100 parts by mass of the second resin constituting the meandering prevention rib guide, there is a problem that the frictional force is high, and 20.0 parts by mass. If it is more, there is a problem of strength reduction.

  The cross-linked polytetrafluoroethylene polymer contained in the second resin constituting the meandering prevention rib guide is the same as the cross-linked polytetrafluoroethylene polymer contained in the transfer belt body, and the degree of cross-linking and the production method are also the same. Since they are the same, detailed description is omitted.

Thus, since the tetrafluoroethylene polymer is crosslinked, the molecular structure of the tetrafluoroethylene polymer becomes three-dimensional, and the molecular structure expands and contracts, resulting in an elastic effect. Moreover, by crosslinking, the constituent molecular weight per unit molecule is increased, the strength of the tetrafluoroethylene polymer itself is improved, and the wear resistance is dramatically improved.
By constituting the meandering prevention rib guide by being contained in the elastomer as the second resin containing the crosslinked tetrafluoroethylene polymer having such characteristics, for example, when bending deformation or a friction phenomenon occurs, the elastomer itself It is possible to improve the resistance to bending deformation and improve the wear resistance.
In addition, as described above, elasticity develops due to cross-linking of the tetrafluoroethylene polymer, so that the creep characteristics of the meandering prevention rib guide are improved, and the creep resistance can be improved.
Thus, by containing the crosslinked polytetrafluoroethylene polymer whose abrasion resistance and creep properties are improved by crosslinking in the second resin constituting the meandering prevention rib guide 14, securing of drivability due to low friction, In addition, wear resistance can be ensured.

  The shape of the meandering prevention rib guide 14 can be appropriately determined depending on the use conditions of the transfer belt 10 and the like, but in order to obtain a sufficient meandering prevention effect, the cross section is preferably substantially rectangular. The width of the meandering prevention rib guide 14 is usually preferably about 1 mm to 10 mm, particularly preferably 4 mm to 7 mm, from the viewpoint of the meandering prevention effect, durability, and the like. Although thickness in particular is not restrict | limited, From viewpoints of a meandering prevention effect, durability, etc., about 1 mm-5 mm are preferable normally, and 3 mm-5 mm are especially preferable.

-Adhesion-
As shown in FIG. 2, the bonding portion 16 for bonding the transfer belt main body 12 and the meandering prevention rib guide 14 is a solid having no adhesive force and adhesive strength at room temperature, but melts by heating and solidifies by cooling. It consists of an adhesive that sometimes develops adhesive strength. The transfer belt main body 12 and the meandering prevention rib guide 14 are bonded by an adhesive portion 16. Since the adhesive portion 16 is uniform in the layer, it is possible to prevent the occurrence of conventional displacement. Also, unlike pressure-sensitive adhesives that are bonded by simply applying pressure at room temperature, the adhesive portion 16 melts by heating, so that the surface of the transfer belt body 12 and the meandering prevention rib guide 14 are wet and familiar, and even fine irregularities enter. It can be solidified and has higher adhesive strength than a pressure sensitive adhesive.

  The adhesive constituting the adhesive portion 16 has good wettability when the transfer belt main body 12 and the meandering prevention rib guide 14 used are heated, and adheres at a temperature that does not damage the transfer belt main body 12 and the meandering prevention rib guide 14. Is appropriately selected from those capable of exhibiting. Here, the adhesive refers to a material that undergoes a change in state such as from solid to liquid, from liquid to solid, etc., when adhering adherends (transfer belt main body 12 and meandering prevention rib guide 14 here), It is distinguished from a pressure-sensitive adhesive that does not require a change in state upon bonding.

  Examples of the adhesive include resin materials such as acrylic, polyester, silicone, natural or synthetic rubber, urethane, and synthetic resin such as vinyl chloride-vinyl acetate copolymer. When a polyimide resin or a polyamide-imide resin is used as the belt body 2 and a polyurethane resin or polyurethane rubber is used as the meandering prevention rib guide 14, the use of the polyester-based adhesive can obtain an endless belt with little damage and displacement. It is preferable because it is possible. The reason for this is not clear, but the carbonyl group of the polyester-based adhesive interacts with the surface of the material of the transfer belt main body 12 and the meandering prevention rib guide 14 with a large amount of oxygen atoms, and the adhesion between the molecules is caused by the polarization. This is thought to be due to the increase. From the viewpoint of flexibility after bonding, it is preferable to use a polyester-based adhesive. A specific example of such an adhesive is D3600 manufactured by Sony Chemical Co., Ltd., which is made of an adhesive in the form of a polyester heat-sensitive sheet having a thickness of 50 μm.

  The thickness of the bonding portion 16 is preferably 0.01 mm to 0.5 mm, and more preferably 0.02 mm to 0.05 mm. When the sheet thickness of the adhesive part 16 is less than 0.01 mm, uniform adhesive strength may not be obtained. When it exceeds 0.5 mm, depending on the temperature and pressure applied to the adhesive part 16 during heat bonding, There is a case where the meandering prevention rib guide 14 is displaced.

  When the Young's modulus of the transfer belt main body 12 has a strength of 2000 MPa or more, the transfer belt main body 12 is broken by a shearing force that acts on the bonding interface between the transfer belt main body 12 and the bonding portion 16 when the transfer belt 10 is running. Since there are few problems such as, it has excellent shear resistance. Thus, since the transfer belt body 12 and the meandering prevention rib guide 14 of the transfer belt 10 of the present invention are excellent in shear resistance, the meandering prevention rib guide 14 is displaced even when the transfer belt 10 is driven for a long time. Problems such as peeling are unlikely to occur.

-Production of transfer belt-
The transfer belt main body 12 is manufactured by applying a coating solution onto a surface of a cylindrical core body (hereinafter referred to as a cylindrical core body) that has been blasted and previously applied with a release agent. The method includes a coating film forming step, a tubular body forming step in which the coating film is heated and dried and heated to form a tubular body, and a peeling step in which the tubular body is peeled from the cylindrical core body. Moreover, you may have another process as needed.

Hereinafter, the manufacturing method of the transfer belt 10 of the present invention will be described in detail for each process.
-Coating film formation process-
In the coating film forming step, first, a coating solution in which a polyimide precursor is dissolved in an aprotic polar solvent is prepared.
As the PI precursor, the above-mentioned crosslinked polytetrafluoroethylene polymer and the above-mentioned conductive agent are mixed in the above-mentioned first resin and mixed and dispersed using a jet mill or the like. Can be used.

  The above polyimide precursor is prepared as a coating solution by dissolving in an aprotic polar solvent such as N-methyl-2-pyrrolidone (NMP), N, N-dimethylacetamide, acetamide, N, N-dimethylformamide and the like. . In addition, selection of the mixing ratio, concentration, viscosity, and the like of the polyimide precursor in the preparation is appropriately adjusted according to the coating method and the like.

When a tubular body is produced on the surface of a cylindrical core body, the film may partially swell due to reaction product water or residual solvent during drying or heating. In that case, the surface of the cylindrical core body is roughened to an arithmetic average roughness Ra in the range of 0.2 to 2 μm, so that the residual solvent or water vapor is generated between the cylindrical core body and the tubular body. It becomes possible to go outside through a slight gap formed between them, and swelling can be prevented. For roughening the surface of the cylindrical core body, a method such as blasting, cutting, sandpapering or the like can be used.
Even if the surface of the cylindrical core body is rough, the surface of the transfer belt body 12 formed on the surface is not rough and is smooth.

  In the peeling step described later, since the tubular body formed on the cylindrical core body may adhere to the surface of the cylindrical core body, it is preferable that the surface of the cylindrical core body is provided with releasability. . In order to impart releasability, a method of coating the cylindrical core with a fluorine resin or silicone resin, a method of applying a release agent to the surface of the cylindrical core, or the like can be used.

  As a method of applying the coating solution to the cylindrical core body, a dip coating method in which the cylindrical core body is immersed in the coating solution and raised (pulled up), or a flow in which the coating solution is discharged onto the surface while rotating the cylindrical core body. Known methods such as a coating method and a blade coating method in which the coating is metalized with a blade can be employed. In the above-described flow coating method or blade coating method, the coating portion is moved horizontally, so that the coating is formed in a spiral shape. However, since the coating solution is slow to dry, the seam is naturally smoothed.

  Note that “applying to the surface of the cylindrical core” means that when a layer is provided on the surface of the cylindrical core, it is applied to the surface of the layer. Further, “rising the cylindrical core body” is a relative relationship with the liquid level at the time of application, and includes the case of “stopping the cylindrical core body and lowering the coating liquid level”.

  When the coating solution is applied by the dip coating method, since the coating solution has a very high viscosity, the film thickness may be too thick. In that case, a dip coating method in which the film thickness is controlled by the following annular body can be applied.

A dip coating method in which the film thickness is controlled by an annular body will be described with reference to FIG. 3 and FIG.
FIG. 3 is a schematic configuration diagram showing an example of a coating apparatus used in this coating method. However, the figure shows only the main part of application, and other devices are omitted.

  In the dip coating method in which the film thickness is controlled by the annular body, as shown in FIG. 3, a circular hole 26 larger than the outer diameter of the cylindrical core body 18 is provided in the coating solution 28 accommodated in the coating tank 20. This is a coating method in which the annular core 24 is floated, the cylindrical core 18 is immersed in the coating solution 28 from the outside of the coating tank 20 through the circular hole 26, and then the cylindrical core 18 is pulled up.

  The annular body 24 is configured to float on the liquid surface of the coating solution 28, and any material may be used as long as it is not attacked by the coating solution 28. For example, the annular body 24 is selected from various metals and plastics. Further, for example, a hollow structure may be used so as to be easily levitated, and legs and arms for supporting the annular body 24 are provided on the outer peripheral surface of the annular body 24 or the application tank 20 in order to prevent sinking. Also good.

  The annular body 24 needs to be able to move freely on the liquid surface of the coating solution 28. Therefore, in addition to a method of floating the annular body 24 on the solution surface so that the coating solution 28 can move with a slight force, a method of supporting the annular body 24 with a roll or a bearing, It is preferable to be installed so as to be freely movable by a supporting method or the like.

  Further, a fixing member for temporarily fixing the annular body 24 may be provided so that the annular body 24 is positioned at the center of the coating tank 20. As such a fixing member, there are a foot member for fixing the annular body 24, a member for fixing the coating tank 20 and the annular body 24, and the like. However, when these fixing members are used, when the cylindrical core body 18 is immersed and then pulled up, the fixing member is detachably disposed so that the annular body 24 can move freely.

  The inner diameter of the circular hole 26 is adjusted in view of a desired coating thickness. The desired coating film thickness (dry film thickness) is the product of the wet film thickness and the non-volatile concentration of the coating solution 28. From this, a desired wet film thickness is obtained. Moreover, it is preferable that the gap between the two obtained from the difference between the inner diameter of the circular hole 26 and the outer diameter of the cylindrical core 18 is in the range of 1 to 2 times the desired wet film thickness. The reason why the range is 1 to 2 times is that the gap does not always become a wet film thickness due to the viscosity and / or surface tension of the coating solution 28. Thus, the desired diameter of the circular hole 26 is determined from the desired dry film thickness and the desired wet film thickness.

  The inner wall surface of the circular hole 26 provided in the annular body 24 may be an inclined surface as shown in FIG. 3 as long as the lower part immersed in the coating solution is wide and the upper part is narrow. It may also be a stepped or curved surface.

  When performing dip coating, the cylindrical core 18 is immersed in the coating solution 28 through the circular hole 26. At this time, the cylindrical core body 18 is prevented from contacting the annular body 24. Next, the cylindrical core body 18 is pulled up through the circular hole 26. At this time, the thickness of the coating film 22 is determined by the gap between the cylindrical core 18 and the circular hole 26. The pulling speed is preferably about 0.1 to 1.5 m / min. The solid concentration of the coating solution preferable for this coating method is in the range of 10 to 40% by mass and the viscosity is in the range of 1 to 100 Pa · s.

  When the cylindrical core body 18 is pulled up through the circular hole 26, a frictional resistance is generated between the cylindrical core body 18 and the annular body 24 due to the intervention of the coating solution 28. The body 24 is slightly lifted. At this time, since the annular body 24 is in a freely movable state, the annular body 24 moves so that the frictional resistance between the cylindrical core body 18 and the annular body 24 is constant in the circumferential direction. That is, when the gap between the annular body 24 and the cylindrical core body 18 is to be narrowed at a certain position, the frictional resistance is increased at the portion where it is narrowed, whereas the frictional resistance is decreased at the opposite side, temporarily. A state in which the frictional resistance is uneven occurs. However, since the annular body 24 can move freely, the outer periphery of the cylindrical core 18 is circular, and the circular hole 26 of the annular body 24 is circular, such frictional resistance is not uniform. Therefore, the annular body 24 automatically moves so that the annular body 24 does not come into contact with the cylindrical core 18.

  Further, the position where the frictional resistance is uniform is a position where the circular shape of the outer periphery of the cylindrical core 18 and the circular shape of the circular hole 26 of the annular body 24 are substantially concentric. Therefore, even when the center of the circle of the cross section of the cylindrical core 18 is deviated within the allowable range in the axial direction, the annular body 24 moves so as to follow it. Accordingly, a coating film 22 having a certain wet film thickness is formed on the surface of the cylindrical core body 18.

  In the coating film forming step, in addition to using the dip coating method, an annular sealing material having a hole slightly smaller than the outer diameter of the cylindrical core body 18 is provided at the bottom of the coating layer. Is inserted through the center of the annular sealing material, the coating solution is accommodated in the coating tank, and the cylindrical core body is sequentially lifted from the lower part to the upper part of the coating tank, and the cylindrical sealing body is inserted through the annular sealing material. You may apply the cyclic | annular coating method which forms a coating film on the surface of this.

-Tubular body formation process-
In this step, the coating film is dried by heating and reacted to form a tubular body on the surface of the cylindrical core 18. In addition, in this invention, this tubular body means the film | membrane which removed the solvent from the coating film, and was made to heat-react.
First, in the tubular body forming step, for the purpose of removing the solvent present in the coating film, heat drying is performed to such an extent that the coating film is not deformed even if left standing. The heating conditions are preferably 5 to 120 minutes in the temperature range of 80 to 180 ° C. At that time, the higher the temperature, the shorter the heating time. In addition to heating, it is also effective to apply wind. Heating may be performed by gradually increasing the temperature within a certain time or by increasing the temperature at a certain speed.

  If the solvent is removed too much from the coating film, the coating film does not yet maintain the strength as a belt, and there is a risk of cracking. Therefore, it is preferable to leave the solvent to some extent (specifically, 15 to 45% by mass in the coating film).

  The process from heating and drying the coating to the heating reaction may be carried out continuously, but the temperature may be temporarily lowered during the course. Here, “reducing the temperature” refers to cooling the coating film that is in a high temperature state by heat drying together with the cylindrical core body to lower the temperature. The temperature to be lowered may be room temperature. Lowering the temperature is effective when the heating and drying apparatus for removing the solvent is different from the heating reaction apparatus for heating and reacting the coating film.

At that time, the coating film shrinks due to a decrease in temperature. The shrinkage rate is in a small range of 0.5 to 2% in the axial direction of the cylindrical core body. However, due to this contraction, the coating film is displaced on the surface of the cylindrical core body. A wider gap is created between them. Once such a gap occurs, residual solvent and the like are easily removed during the heating reaction.
When the heat drying apparatus and the heat reaction apparatus are the same, it is not necessary to lower the temperature once.

  In the tubular body forming step, after the above-mentioned drying, the tubular body is formed by subjecting the coating film to a heat reaction for 20 minutes to 60 minutes, preferably in the range of 300 ° C. to 450 ° C., more preferably around 350 ° C. be able to. During the heating reaction, if the solvent remains in the coating film, the film may swell. Therefore, it is preferable to completely remove the residual solvent before reaching the final temperature of heating. Before heating, heat drying in a temperature range of 200 ° C. to 250 ° C. for 10 minutes to 30 minutes to remove the residual solvent, followed by heating by gradually increasing the temperature stepwise or at a constant rate. It is preferable to form a tubular body.

-Peeling process-
After the heating reaction, the transfer belt body 12 can be obtained by passing through this step of cooling the cylindrical core body 18 to room temperature and peeling the formed tubular body.
Since the release agent is applied to the cylindrical core body 18 in advance, the inner peripheral surface of the tubular body and the outer peripheral surface of the cylindrical core body 18 are not in direct contact with each other. The transfer belt body 12 can be obtained by easily peeling the body.

  Note that the transfer belt main body 12 that has been extracted has inferior film thickness uniformity at the both ends, or film fragments are attached, so that the portion is cut as an unnecessary portion. Furthermore, drilling (punching) processing, rib attaching processing, etc. may be performed as needed.

-Meandering rib guide adhesion (production of transfer belt)-
The transfer belt 10 can be manufactured by adhering the meandering prevention rib guide 14 to the transfer belt main body 12 manufactured as described above. The meandering prevention rib guide 14 may be provided only on one side edge of the transfer belt main body 12, but both side edges (both ends in the width direction) of the transfer belt main body 12 from the viewpoint of further meandering prevention effect, durability, reinforcement effect and the like. Part). The adhesion position of the meandering prevention rib guide 14 to the transfer belt main body 12 (distance from the side edge of the transfer belt main body 12) is appropriately set according to the application and function of the transfer belt 10, the apparatus using the transfer belt 10, and the like.

  As shown in FIG. 1, the meandering prevention rib guide 14 is preferably provided on the entire periphery from the viewpoint of the reinforcing effect of the transfer belt body 12, but even if there is a gap of about 1 mm to 10 mm at the joint of the meandering prevention rib guide 14. Good.

  The method for adhering the meandering prevention rib guide 14 to the transfer belt main body 12 is not particularly limited, but a sheet-like adhesive portion 16 composed of release paper on one side is temporarily adhered to the meandering prevention rib guide 14 at a temperature of about 80 degrees. After the release paper is peeled off, it is preferable to heat the transfer belt body 12 at a temperature of 100 ° C. to 180 ° C. and perform the main adhesion. In this way, the transfer belt main body 12 and the meandering prevention rib guide 14 are integrated by the bonding portion 16 to manufacture the transfer belt 10.

In addition, it is important to bond without bubbles, and usually a method such as bonding with a hand roller, rubber roller or press, bonding under reduced pressure, or bonding under pressure is used. It is preferable. Further, the surface of the meandering prevention rib guide 14 or the surface of the transfer belt body 12 may be subjected to corona treatment, blast treatment, primer treatment, aging, or the like to improve the adhesive force.
The transfer belt 10 thus obtained can be used as a transfer belt in an image forming apparatus such as an electrophotographic copying machine or a laser printer.

<Image forming apparatus>
The image forming apparatus of the present invention is not particularly limited as long as it is an intermediate transfer body type image forming apparatus using the transfer belt 10 of the present invention. For example, a normal monocolor image forming apparatus that contains only a single color toner in a developing device, or a color image formation in which a toner image carried on an image carrier such as a photosensitive drum is sequentially subjected to primary transfer to an intermediate transfer member. And a tandem type color image forming apparatus in which a plurality of image carriers having developing devices of respective colors are arranged in series on an intermediate transfer member.

A color image forming apparatus that repeats primary transfer will be described below as an example of the image forming apparatus of the present invention.
An image forming apparatus 80 shown in FIG. 4 performs development with the image carrier 30, the transfer belt 10, the bias roller 34 as a transfer electrode, a paper tray 36 for storing a recording medium 68, and BK (black) toner. Developing device 44, developing device 38 for developing with Y (yellow) toner, developing device 40 for developing with M (magenta) toner, developing device 42 for developing with C (cyan) toner, transfer A belt cleaner 49 for removing residual toner on the belt 10, a peeling claw 62, a support roll 48 for supporting the transfer belt 10, a support roll 50, a support roll 54, a backup roller 56, a conductive roller 52, and an electrode The recording medium 68 stored in the roller 58, the cleaning blade 70, and the paper tray 36 is picked up. And a pickup roller 66 for guiding the installation position of the feed roller 143 Te.
The backup roller 56 is provided so as to face the bias roller 34 with the transfer belt 10 interposed therebetween. In the vicinity of the backup roller 56, an electrode roller 58 that rotates in pressure contact with the backup roller 56 is provided.

  The meandering prevention rib guide provided inside the transfer belt 10 is positioned so as to contact the side edges of the support roll 48, the support roll 50, and the support roll 54. A groove (not shown) is provided on the outer periphery of each of the support roll 48, the support roll 50, and the support roll 54, and the meandering of the transfer belt 10 is suppressed by guiding the meandering prevention rib guide through the grooves. .

  In the image forming apparatus 80, the image carrier 30 is rotated in the direction of arrow F, and the surface thereof is uniformly charged by a charging device (not shown). When the uniformly charged image carrier 30 is scanned and exposed by an image writing device (not shown) such as a laser writing device (not shown), an electrostatic latent image of the first color (for example, BK). Are formed on the image carrier 30. The electrostatic latent image is developed by the developing device 44 and a visualized toner image T is formed on the image carrier 30. When the toner image T reaches the primary transfer portion where the conductive roller 52 is disposed by the rotation of the image carrier 30, an electric field having a reverse polarity is applied to the toner image T by the conductive roller 52, and the toner image T is statically moved. Primary transfer is performed by rotation of the transfer belt 10 in the direction of arrow G while being electrically attracted to the transfer belt 10.

  Similarly, the second color toner image, the third color toner image, and the fourth color toner image are sequentially formed on the image carrier 30 and then superposed on the transfer belt 10 to obtain a multicolor toner. An image is formed. The toner at this time may be a one-component toner or a two-component toner.

  The multicolor toner image transferred to the transfer belt 10 reaches the installation position of the bias roller 34 by the rotation of the transfer belt 10.

The recording medium 68 is taken out one by one from the paper tray 36 by the pickup roller 66, and is fed by the feed roller 64 between the transfer belt 10 and the bias roller 34 at a predetermined timing. The multi-color toner image carried on the transfer belt 10 is transferred to the fed recording medium 68 by the pressure contact conveyance by the bias roller 34 and the backup roller 56 and the rotation of the transfer belt 10.
To transfer the multicolor toner image, a transfer voltage having the same polarity as the polarity of the multicolor toner image is applied to an electrode roller 58 that is in pressure contact with a backup roller 56 that is disposed to face the bias roller 34 and the transfer belt 10. As a result, the multicolor toner image is transferred to the recording medium 68 by electrostatic repulsion. As described above, an image can be formed on the recording medium 68.

  The recording medium 68 to which the multicolor toner image has been transferred is peeled off from the transfer belt 10 by the peeling claw 113, conveyed to a fixing device (not shown), and fixed to a permanent image by pressing / heating treatment. The Note that the residual toner is removed from the transfer belt 10 after the transfer of the multicolor toner image to the recording medium 68 by the belt cleaner 109. Further, the cleaning roller 70 made of polyurethane or the like is always in contact with the bias roller 34, and foreign matters such as toner particles and paper dust adhering to the transfer are removed.

  In the case of transfer of a single color image, the primary transferred toner image T is immediately secondarily transferred and conveyed to the fixing device. In the case of transfer of a multicolor image by superimposing a plurality of colors, the toner image of each color is transferred to the primary transfer unit. Therefore, the rotation of the transfer belt 10 and the image carrier 30 are controlled so that the toner images of the respective colors do not shift by synchronizing the rotations of the transfer belt 10 and the image carrier 30 so that they coincide with each other.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail using an Example, this invention is not limited by the following Example.

Example 1
<Preparation of transfer belt body>
In polyimide varnish (U imide varnish KX, manufactured by Unitika Ltd.), 15 parts by weight of crosslinked PTFE powder (XF powder, manufactured by Hitachi Cable, volume average primary particle size 20 μm, crosslinking degree 98%) with respect to 100 parts by weight of solid content, 28 parts by weight of carbon black (SB-4) was added and mixed and dispersed using a jet mill to obtain a coating solution.
The polyimide varnish (U-imide varnish KX, manufactured by Unitika) contains a solvent (solid content concentration 20% by mass) (solvent: 400 parts by weight of N-methyl-2-pyrrolidone (converted to 20 wt%)).

  As the cylindrical core to which the coating solution is applied, an aluminum cylinder having an outer diameter of 302 mm and a length of 400 mm is used, and the surface of the cylindrical core is roughened by blasting. A thickness Ra of 0.5 μm was prepared. Further, a silicone release agent (trade name: KS700, manufactured by Shin-Etsu Chemical Co., Ltd.) was applied to the surface of the cylindrical core so as to have a thickness of 2 μm, and baked at 300 ° C. for 1 hour.

On the other hand, as an annular body, a Teflon (registered trademark) ring having an outer diameter of 320 mm and a triangular cross section is fitted inside a stainless steel hollow ring having an outer diameter of 400 mm, an inner diameter of 320 mm, and a height of 30 mm. What was made to use was used. The minimum hole diameter of this Teflon (registered trademark) ring was 303.6 mm.
Next, after floating the annular body on the coating solution, the annular body is fixed so as not to move, the axial direction of the cylindrical core body is vertical, and the cylindrical core body is inserted into the hole of the annular body at 500 mm / min. Inserted and dipped at speed. Next, the fixation of the annular body was released, and the cylindrical core body was pulled up at a speed of 150 mm / min. During the pulling, the annular body did not contact the cylindrical core, and a coating film having a wet film thickness of about 700 μm was formed on the surface of the cylindrical core. Next, the cylindrical core body on which the coating film was formed was placed in a drying furnace. After maintaining at 320 ° C. for 2 hours and 320 ° C. for 30 minutes to obtain a tubular body, the tubular body was peeled from the cylindrical core body to obtain a transfer belt body.
The solvent contained in the coating solution was dried at 120 ° C. for 30 minutes.
Since the release agent was previously applied to the surface of the cylindrical core body, the inner peripheral surface of the tubular body (transfer belt main body) did not adhere to the cylindrical core body at the time of peeling. The transfer belt body had a thickness of 80 μm and a surface resistivity of 10.8 log / □.

<Evaluation>
The transfer belt body obtained in Example 1 was mounted on a color copier DocuColor 1250 manufactured by Fuji Xerox Co., Ltd., and a running test of 300,000 sheets was performed. As a result, there were no image defects (color loss, image distortion, etc.) at the initial stage and after a running test after 200,000 sheets. Further, no toner or paper dust adhered to the surface of the transfer belt.

(Example 2)
<Preparation of transfer belt body>
A transfer belt body was prepared in the same manner as in Example 1 except that the amount of the crosslinked PTFE powder was 5 parts by weight in Example 1.

<Evaluation>
In the same manner as in Example 1, the transfer belt body obtained in Example 2 was mounted on a color copier DocuColor 1250 manufactured by Fuji Xerox Co., Ltd., and a running test for 300,000 sheets was performed. As a result, there were no image defects (color loss, image disturbance, etc.) at the initial stage and after a running test after 300,000 sheets. Further, no toner or paper dust adhered to the surface of the transfer belt.

(Example 3)
<Preparation of transfer belt body>
A transfer belt body was prepared in the same manner as in Example 1 except that the amount of the crosslinked PTFE powder was 25 parts by weight in Example 1.

<Evaluation>
In the same manner as in Example 1, the transfer belt body obtained in Example 3 was mounted on a color copier DocuColor 1250 manufactured by Fuji Xerox Co., Ltd., and a running test on 300,000 sheets was performed. As a result, there was no occurrence of image defects (color loss, image disturbance, etc.) at the initial stage and after a running test after 300000 sheets. On the other hand, although there was no problem, a slight difference in image density was observed. Further, no toner or paper dust adhered to the surface of the transfer belt.

Example 4
A transfer belt body was prepared in the same manner as in Example 1 except that the amount of the crosslinked PTFE powder was changed to 0.5 parts by weight in Example 1.

<Evaluation>
The transfer belt body obtained in Example 4 was mounted on a color copier DocuColor 1250 manufactured by Fuji Xerox Co., Ltd. in the same manner as in Example 1, and a running test for 300,000 sheets was performed. As a result, there was no occurrence of image defects (color loss, image disturbance, etc.) at the initial stage and after a running test after 300,000 sheets. On the other hand, the image on the surface of the transfer belt was not affected, but surface contamination with a small amount of toner was observed.

(Comparative Example 1)
A transfer belt main body was produced in the same manner as in Example 1 except that PTFE powder that had not been cross-linked in Example 1 was used and the addition amount was 15 parts by weight.

<Evaluation>
The transfer belt body obtained in Comparative Example 1 was mounted on a color copier DocuColor 1250 manufactured by Fuji Xerox Co., Ltd. in the same manner as in Example 1, and a running test of 300,000 sheets was performed. As a result, an image defect occurred at the time of traveling 220,000 sheets, and the belt surface was uneven due to wear.

(Comparative Example 2)
A transfer belt main body was produced in the same manner as in Example 1 except that no fluororesin powder was added in Example 1.

<Evaluation>
The transfer belt body obtained in Comparative Example 2 was mounted on a color copier DocuColor 1250 manufactured by Fuji Xerox Co., Ltd. in the same manner as in Example 1, and a running test for 300,000 sheets was performed. As a result, an image defect occurred when 150,000 sheets were run, and the surface of the belt was contaminated with toner.

(Example 5)
<Preparation of transfer belt>
Example 1 A meandering prevention rib guide in which 15 parts by weight of crosslinked PTFE powder (trade name: XF powder, manufactured by Hitachi Cable, volume average primary particle size 20 μm, degree of crosslinking 97%) is added to 100 parts by weight of urethane rubber The transfer belt body manufactured in step 1 was subjected to an adhesive treatment using an adhesive (trade name: Super X, manufactured by Cemedine Co., Ltd.) to prepare a transfer belt provided with a meandering prevention rib guide.

<Evaluation>
The transfer belt obtained in Example 5 was mounted on a color copier DocuColor 1250 manufactured by Fuji Xerox Co., Ltd., and a paper running test (image evaluation) on 300,000 sheets was performed. As a result, there were no image defects due to wear damage of the meandering prevention rib guide, peeling off from the transfer belt, dirt adhesion to the surface of the meandering prevention rib guide, running failure, etc. even after the initial and after running 300,000 sheets.

(Example 6)
<Preparation of transfer belt>
In Example 5, a transfer belt was produced in the same manner as in Example 5 except that the amount of the crosslinked PTFE powder added was 3 parts by weight.

<Evaluation>
In the same manner as in Example 5, the transfer belt obtained in Example 6 was mounted on a color copier DocuColor 1250 manufactured by Fuji Xerox Co., Ltd., and a running test of 300,000 sheets was performed. As a result, there were no image defects due to wear damage of the meandering prevention rib guide, peeling off from the transfer belt, dirt adhesion to the surface of the meandering prevention rib guide, running failure, etc. even after the initial and after running 300,000 sheets.

(Example 7)
<Preparation of transfer belt>
In Example 5, a transfer belt was produced in the same manner as in Example 5 except that 25 parts by weight of the crosslinked PTFE powder was added.

<Evaluation>
In the same manner as in Example 5, the transfer belt obtained in Example 7 was mounted on a color copier DocuColor 1250 manufactured by Fuji Xerox Co., Ltd., and a running test of 300,000 sheets was performed. As a result, no image defect occurred after running 300,000 sheets, but peeling of the meandering prevention rib guide from the transfer belt was observed.

(Example 8)
<Preparation of transfer belt>
A transfer belt was produced in the same manner as in Example 5 except that 0.1 part by weight of the crosslinked PTFE powder was added in Example 5.

<Evaluation>
In the same manner as in Example 5, the transfer belt obtained in Example 8 was mounted on a color copying machine DocuColor 1250 manufactured by Fuji Xerox Co., Ltd., and a running test of 300,000 sheets was performed. As a result, there was no image defect after running 300,000 sheets, but the rib guide was deformed.

(Comparative Example 3)
<Preparation of transfer belt>
In Example 5, a transfer belt was produced in the same manner as in Example 5 except that a fluorine resin not subjected to electron beam crosslinking (low molecular weight fluorine resin powder_Lublon L5 (manufactured by Daikin Industries)) was added.

<Evaluation>
In the same manner as in Example 5, the transfer belt obtained in Comparative Example 3 was mounted on a color copier DocuColor 1250 manufactured by Fuji Xerox Co., Ltd., and a running test of 300,000 sheets was performed. As a result, there was no problem at the initial stage, but image disturbance occurred after running 200,000 sheets, and the rib guide surface at that time was damaged by wear.

It is the structure schematic of the meandering prevention rib guide of this invention. FIG. 4 is a schematic configuration diagram illustrating an adhesion portion between a transfer belt main body and a meandering prevention rib guide. It is a schematic diagram showing a method for producing a transfer belt ・ 1 is a schematic configuration diagram illustrating an example of an image forming apparatus including a transfer belt of the present invention as an intermediate transfer belt.

Explanation of symbols

12 Transfer belt body (transfer belt)

Claims (2)

  A transfer belt for use in an image forming apparatus, wherein the transfer belt is formed from a first resin containing a crosslinked polytetrafluoroethylene polymer.   An image forming apparatus comprising the transfer belt according to claim 1.

Images