JP2017003935A - Intermediate transfer body and manufacturing method of the same, and image forming apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intermediate transfer body that has a high damage repairing property irrespective of environmental temperature and humidity.SOLUTION: There is provided an intermediate transfer body satisfying the following requirements (1) to (4). (1) The intermediate transfer body includes a base layer and a surface layer provided thereon. (2) The surface layer contains a crosslinked body in which polyrotaxane is cured by a curing agent. (3) The polyrotaxane includes at least cyclic molecules, linear molecules penetrating the cyclic molecules in a skewing manner, and blocking groups that are joined to both terminals of the linear molecule to prevent elimination of the cyclic molecules. (4) The surface layer contains 100 to 10000 ppm of a solvent that has been used in manufacture of a coating liquid of the polyrotaxane.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an intermediate transfer member equipped in an image forming apparatus such as a copy printer, a manufacturing method thereof, an image forming apparatus using the intermediate transfer member, particularly an intermediate transfer member suitable for full-color image formation, and the use thereof. The present invention relates to an image forming apparatus.

Conventionally, in an electrophotographic image forming apparatus, a seamless belt is used as a member for various purposes. Particularly in recent full-color image forming apparatuses, yellow, magenta, cyan and black developed images of four colors are once color-superimposed on a seamless belt-shaped intermediate transfer member, and then collectively transferred onto a transfer medium such as paper. An intermediate transfer body method is used.
This intermediate transfer member system has been used in a system that uses four color developing devices for one photosensitive member, but has a drawback in that the printing speed is slow. For this reason, in high-speed printing, a four-tandem tandem system is used in which photoconductors are arranged for four colors and each color is continuously transferred to paper. However, in this method, there are fluctuations in the paper depending on the environment, and it is very difficult to match the position accuracy of overlapping each color image, which causes a color misregistration image. Therefore, in recent years, it has become the mainstream to adopt the intermediate transfer body method for the quadruple tandem method.

Under such circumstances, the required characteristics (high-speed transfer, position accuracy) for the intermediate transfer belt are stricter than before, and it is necessary to satisfy the characteristics corresponding to these requirements. In particular, regarding positional accuracy, it is required to suppress fluctuations due to deformation such as elongation of the belt itself due to continuous use. Further, the intermediate transfer belt is laid out over a wide area of the apparatus, and is required to be flame retardant because a high voltage is applied for transfer. In order to meet such requirements, polyimide resin, polyamideimide resin, and the like, which are high elastic modulus and high heat resistance resins, are mainly used as intermediate transfer belt materials.
However, the intermediate transfer belt made of polyimide resin has high surface hardness due to its high strength, and when the toner image is transferred, a high pressure is applied to the toner layer, the toner is locally aggregated and a part of the image is not transferred. A so-called hollow image may occur. In addition, since the contact followability with a contact member such as a photoconductor or paper in the transfer portion is inferior, a partial contact failure portion (gap) may occur in the transfer portion, and transfer unevenness may occur.

In recent years, full-color electrophotography has been used to form images on various types of paper. Not only ordinary smooth paper but also slippery, smooth paper such as coated paper, recycled paper, embossed The use of rough surfaces such as paper, Japanese paper and kraft paper is increasing. Such followability to papers having different surface properties is important. If the followability is poor, uneven unevenness of color and unevenness of color tone occur.
In order to solve this problem, various intermediate transfer belts in which a relatively flexible elastic layer is laminated on a base layer have been proposed.

Patent Document 1 proposes that polyrotaxane is used as a surface layer of an intermediate transfer belt to improve transfer to paper and scratch resistance. However, with this configuration, there are problems with the amount of residual solvent of polyrotaxane and problems that it is difficult or impossible to repair when scratched depending on the temperature and humidity environment (especially low temperature and low humidity). Not reach.
Patent Document 2 proposes that the volatile content of the base layer and the surface layer of the intermediate transfer belt is defined to improve transferability and suppress the breakage of the surface layer. However, even in this configuration, once it is damaged, it cannot be restored. Moreover, the surface layer material to be used is a very hard thing, and the meaning differs from this invention.
Patent Document 3 proposes that a solvent having a boiling point of 150 to 220 ° C. is used to dissolve the elastic layer of the intermediate transfer belt, thereby improving the smoothness of the coating film and improving the transferability. The purpose is different from the improvement of flaw repairability, which is a technique related to the present invention and is the aim of the present invention.
In short, all of the techniques of the above-mentioned patent documents 1 to 3 are technical ideas from the viewpoint of how to not scratch the surface or reduce the smoothness. It is not described at all.

  The present invention has been made in view of the above prior art, and an object thereof is to provide an intermediate transfer member having high flaw repairability regardless of the temperature and humidity environment.

As a result of intensive studies, the present inventors can obtain an intermediate transfer body capable of realizing high flaw repairability regardless of the temperature and humidity environment by controlling the residual solvent amount in the polyrotaxane surface layer to a range of 100 to 10,000 ppm. I found.
That is, the above problem is solved by the following invention 1).
1) An intermediate transfer member that satisfies the following requirements (1) to (4):
(1) It has a base layer and a surface layer provided thereon.
(2) The surface layer contains a crosslinked product obtained by curing polyrotaxane with a curing agent.
(3) The polyrotaxane includes at least a cyclic molecule, a linear molecule penetrating through the cyclic molecule, and a blocking group that prevents elimination of the cyclic molecule bonded to both ends of the linear molecule. Have
(4) The surface layer contains 100 to 10,000 ppm of residual solvent.

  According to the present invention, it is possible to provide an intermediate transfer member having high flaw repairability regardless of the temperature and humidity environment.

FIG. 3 is a diagram illustrating a basic layer configuration of an intermediate transfer member of the present invention. The schematic diagram which shows notionally the basic structure of the polyrotaxane used by this invention. FIG. 3 is a schematic diagram of a main part of an example of an image forming apparatus equipped with the intermediate transfer member of the present invention as a seamless belt. FIG. 6 is a schematic diagram of a main part of another example of an image forming apparatus equipped with the intermediate transfer member of the present invention as a seamless belt.

Hereinafter, the present invention 1) will be described in detail. However, since the following 2) to 7) are also included in the embodiment of the present invention, these will be described together.
2) The intermediate transfer member according to 1), wherein the boiling point of the residual solvent is 100 ° C. to 160 ° C.
3) The intermediate transfer member according to 1) or 2), wherein the thickness of the surface layer is 20 to 200 μm.
4) The intermediate transfer member according to any one of 1) to 3), wherein the form is a seamless belt.
5) The intermediate transfer member according to any one of 1) to 4), wherein a base layer material is applied to an outer surface of a cylindrical mold and dried to form a base layer, and then a surface layer is laminated thereon. Manufacturing method.
6) An image carrier that can form a latent image and can carry a toner image; a developing unit that develops the latent image formed on the image carrier with toner; and a toner image developed by the developing unit is subjected to primary transfer. The intermediate transfer member according to any one of 1) to 4), further comprising: an intermediate transfer member to be transferred; and a transfer unit that secondarily transfers the toner image carried on the intermediate transfer member to a recording medium. An image forming apparatus characterized by being a body.
7) The image forming apparatus according to 6), wherein a plurality of image carriers having developing units for each color are arranged in series to form a full-color image.

[Intermediate transfer member]
An intermediate transfer member (intermediate transfer belt) is one of important members that require electrical characteristics in an electrophotographic image forming apparatus. In the image forming apparatus, a seamless belt is used for some members, but a seamless belt may be used as an intermediate transfer member.
Hereinafter, the intermediate transfer member of the present invention will be described.
The intermediate transfer member of the present invention is suitably equipped as an intermediate transfer belt in an intermediate transfer belt type image forming apparatus. The image forming apparatus performs primary transfer by sequentially superimposing a plurality of color toner developed images sequentially formed on an image carrier (for example, a photosensitive drum) on an intermediate transfer belt, and the primary transfer image is recorded on a recording medium. This is a device that performs secondary transfer in a batch.
FIG. 1 shows the basic layer structure of the intermediate transfer member of the present invention. The surface layer 12 is laminated on the base layer 11. The base layer 11 is made of a rigid material that can be relatively bent, and the surface layer 12 is made of a flexible material. In addition to the base layer and the surface layer, an intermediate layer may be provided as necessary. Examples of the intermediate layer include a primer layer for improving adhesiveness and a relatively soft elastic layer such as elastomer or rubber for improving followability to a transfer medium.

≪Base layer≫
Examples of the constituent material of the base layer 11 include those containing a filler or an additive (electric resistance adjusting material) for adjusting electric resistance in the resin.
From the viewpoint of flame retardancy, the resin is preferably a fluorine-based resin such as polyvinylidene fluoride (PVDF), a copolymer of tetrafluoroethylene and ethylene (ETFE), a polyimide resin, a polyamideimide resin, and the like. From the viewpoint of high elasticity and heat resistance, a polyimide resin or a polyamideimide resin is particularly preferable.
As the polyimide resin or the polyamide-imide resin, commercial products of various companies such as Toray DuPont, Ube Industries, Nippon Nippon Chemical Co., Ltd., JSR, Unitika, IST, Hitachi Chemical, Toyobo, Arakawa Chemical Co., Ltd. can be used.

Although the said electrical resistance adjusting material is not specifically limited, For example, a metal oxide, carbon black, an ionic conductive agent, a conductive polymer material etc. are mentioned.
Examples of the metal oxide include zinc oxide, tin oxide, titanium oxide, zirconium oxide, aluminum oxide, and silicon oxide. Moreover, in order to improve dispersibility, the metal oxide may be subjected to surface treatment in advance. Examples of carbon black include ketjen black, furnace black, acetylene black, thermal black, and gas black. Examples of the ionic conductive agent include tetraalkylammonium salts, trialkylbenzylammonium salts, alkylsulfonates, alkylbenzenesulfonates, alkyl sulfates, glycerol fatty acid esters, sorbitan fatty acid esters, polyoxyethylene alkylamines, polyoxyethylene fatty acids. Alcohol ester, alkyl betaine, lithium perchlorate, etc. are mentioned. These may be used in combination.
In addition, a dispersion aid, a reinforcing material, a lubricant, a heat conductive material, an antioxidant, and the like are further added to the coating liquid containing a resin component used in the production of the intermediate transfer member of the present invention, if necessary. May be.

When the intermediate transfer member is a seamless belt, an electric resistance adjusting material is used so that the surface resistivity is 1 × 10 ⁸ to 1 × 10 ¹³ Ω / □ and the volume resistivity is 1 × 10 ⁸ to 1 × 10 ¹¹ Ω · cm. It is preferable to contain. The electrical resistance adjusting material is selected from the viewpoint of mechanical strength, so that the addition amount is sufficient so that the film is brittle and does not easily break. That is, using the coating liquid in which the blending ratio of the resin component (for example, polyimide resin precursor or polyamideimide resin precursor) and the electrical resistance adjusting material is appropriately adjusted, the electrical characteristics (surface resistivity and volume resistivity) It is preferable to manufacture a seamless belt that balances mechanical strength.

  When carbon black is used, the content of the electric resistance adjusting material is preferably 10 to 25% by mass, more preferably 15 to 20% by mass, based on the total solid content in the coating liquid. Moreover, when using a metal oxide, 1-50 mass% of the total solid of a coating liquid is preferable, More preferably, it is 10-30 mass%. If the content is equal to or greater than the lower limit value of each range, sufficient uniformity of the resistance value can be obtained, and the variation of the resistance value with respect to an arbitrary potential does not increase. If the content is less than or equal to the upper limit value of the above ranges, an intermediate transfer belt having practically sufficient mechanical strength can be obtained.

There is no restriction | limiting in particular in the film thickness of a base layer, Although it can select suitably according to the objective, 30-150 micrometers is preferable, 40-120 micrometers is more preferable, 50-80 micrometers is especially preferable. If the thickness of the base layer is 30 μm or more, the belt will not be torn by cracking, and if it is 150 μm or less, the seamless belt will not be broken by bending. Moreover, it is advantageous at a durable point that it is 50-80 micrometers.
The method for measuring the thickness of the base layer is not particularly limited and can be appropriately selected according to the purpose. For example, measurement using a contact type or eddy current type thickness meter, or a cross-section of the film by a scanning electron microscope (SEM) The method of measuring by is mentioned.

<< Surface >>
The surface layer 12 has at least a cyclic molecule, a linear molecule penetrating through the cyclic molecule in a stab-like manner, and a blocking group for preventing the elimination of the cyclic molecule bonded to both ends of the linear molecule. It contains a crosslinked product obtained by curing polyrotaxane with a curing agent (crosslinking agent).
That is, in the surface layer, the curing agent is bonded to the polyrotaxane through the cyclic portion of the polyrotaxane. With this crosslinked polyrotaxane, excellent transferability can be realized.
In addition, if the polyrotaxane is cured so that the flexibility thereof is maintained moderately, the surface layer can be made to have a preferable hardness for improving transferability, and as a result, both the flexibility of the polyrotaxane and the flaw repairability can be achieved. Can do.

<Polyrotaxane>
FIG. 2 is a schematic diagram conceptually showing the basic structure of the polyrotaxane used in the present invention. 1 is a polyrotaxane, 2 is a linear molecule, 3 is a cyclic molecule, 3A is a lipophilic modifying group, and 4 is a blocking group. However, the lipophilic modification group 3A may not be present.
A polyrotaxane is a molecule in which a plurality of cyclic molecules are fitted into a dumbbell-shaped linear molecule having blocking groups at both ends. Dumbbell-shaped blocking groups at both ends play a role in preventing the elimination of cyclic molecules. In addition, since the linear molecule is not fixed covalently to the cyclic molecule, the linear molecule can freely move through the hole of the cyclic molecule, and the cyclic molecule also moves along the linear molecule. It is possible.
Further, either one or both of a linear molecule and a cyclic molecule may have a lipophilic modification group. This lipophilic modified polyrotaxane is easily dissolved in an organic solvent and is easily applied as a surface layer. Examples of the modifying group exhibiting lipophilicity include an alkyl group and a benzyl group.

  In the lipophilic modified polyrotaxane 1 in FIG. 2, the linear molecule 2 penetrates the hole (opening) of the cyclic molecule 3 and is included by the cyclic molecule 3, and the cyclic molecule 3 has the lipophilic modifying group 3A. doing. That is, when stress is applied, the cyclic molecule 3 can move freely along the linear molecule 2 like a pulley. As a result, the stretchability and flexibility are excellent, and the followability to the transfer medium is improved. The linear molecule 2 is not particularly limited as long as it is a molecule that is substantially linear and has a reactive functional group capable of binding the blocking group 4 at the terminal. The blocking group 4 needs to be sufficiently bulky so that the cyclic molecule 3 cannot be detached from the linear molecule 2.

  The molecular weight of the linear molecule 2 having a functional group at the terminal is preferably 1000 to 50000, more preferably 10,000 to 40000, and particularly preferably 20000 to 35000. If the molecular weight is 1000 or more, the pulley effect by the cyclic molecules 3 is sufficiently obtained, the flexibility of the coating film is not lowered, and the scratch resistance and followability to the transfer medium are not deteriorated. In addition, when the molecular weight is 50000 or less, the viscosity when used as a coating liquid does not become too high, and appearance deterioration such as smoothness and gloss does not occur.

The cyclic molecule 3 is not particularly limited as long as the cyclic molecules are not cross-linked and can move through the linear molecule 2 into the ring. Further, the cyclic molecule 3 does not necessarily have to be completely closed, and a part of the ring may be opened to the extent that it does not leave the linear molecule 2.
Preferable examples include cyclodextrins and crown ethers. Of these, cyclodextrins are preferred because they can easily form an inclusion compound with an organic compound.
Cyclodextrins are compounds in which a plurality of glucoses are linked in a cyclic manner with α-1,4 bonds, and α-, β-, and γ-cyclodextrins formed with 6, 7, and 8 glucoses. Particularly preferred. From the viewpoint of inclusion, α-cyclodextrin is preferred. In addition, modified dextrins in which at least one of the hydroxyl groups of cyclodextrins is substituted with another organic functional group are preferable in terms of improving solubility in a solvent.
Furthermore, as the cyclic molecule 3, one having a reactive group is preferable in that it can be easily bonded to the lipophilic modifying group 3A or the like. Examples of such a reactive group include a hydroxyl group, a carboxyl group, and an amino group, but a hydroxyl group is preferable because it does not react with the blocking group 4 when the blocking group 4 is formed.

The cyclic molecule 3 can be used singly or in combination of two or more. In addition, the number (inclusion amount) of the cyclic molecule 3 that includes the linear molecule 2 is arbitrary as long as the cyclic molecule 3 itself includes the linear molecule 2 and can move freely like a pulley. Can be set.
Examples of the polyrotaxane 1 suitable for the present invention include: the linear molecule 2 is polyethylene glycol, the cyclic molecule 3 is α-cyclodextrin, the blocking group 4 is an adamantane group, and part of the hydroxyl group of the α-cyclodextrin Alternatively, all of them may be modified with a modifying group, and the modifying group may have a structure having a —CO (CH ₂ ) ₅ OH group that is a modifying group with caprolactone bonded to a —C ₃ H ₆ —O— group. . In addition, this polyrotaxane can also be manufactured by the well-known method as described in patent 437649 etc., and can also use commercial items, such as Advanced Soft Materials.

  The molecular weight of the polyrotaxane 1 is preferably 15,000 to 1,000,000, more preferably 180,000 to 800,000. If molecular weight is 15000 or more, the fall of the softness | flexibility of a coating film and scratch resistance will not deteriorate. Further, if the molecular weight is 1000000 or less, it does not become difficult to mix with other substances, and the followability to uneven transfer media is not caused by the decrease in flexibility. The molecular weight can be determined by gel permeation chromatography (GPC).

<Curing agent (crosslinking agent)>
The curing agent (crosslinking agent) used in the present invention is not particularly limited and may be a commercially available product, but is appropriately selected so that the surface layer has a hardness preferable for transferability while maintaining the flexibility of the polyrotaxane appropriately.
Specific examples include melamine resins, polyisocyanate compounds, blocked isocyanate compounds, cyanuric chloride, trimesoyl chloride, terephthaloyl chloride, epichlorohydrin, dibromobenzene, glutaraldehyde, phenylene diisocyanate, trilein diisocyanate, divinyl sulfone. 1,1'-carbonyldiimidazole and alkoxysilanes. These can be used alone or in combination of two or more, but is preferably an isocyanate from the viewpoint of easy crosslinking, and among them, a hexamethylene diisocyanate polyisocyanate is preferable. The reason for this is that hexamethylene diisocyanate has two primary isocyanate groups and thus has high reactivity and less uncrosslinked OH groups, so that the cross-linked intermediate transfer member is excellent in toner releasability, and isocyanate. This is because, since six methylene groups are present between the groups, the flexibility of the crosslinked intermediate transfer member is excellent, so that the transferability is improved.

Further, blocked isocyanate is more preferable because of high storage stability at room temperature.
Block isocyanate protects active isocyanate groups with blocking agents such as oximes, diketones, phenols, caprolactams, etc., maintains stability under normal conditions, dissociates the blocking agent by heat treatment, and regenerates active isocyanate groups It causes a curing / crosslinking reaction. The isocyanate preferably used in the present invention is a blocked isocyanate of hexamethylene diisocyanate polyisocyanate.
As the isocyanate curing agent, commercially available products can be used. For example, “Duranate” manufactured by Asahi Kasei Chemicals, “Takenate” manufactured by Mitsui Chemicals, “Coronate” manufactured by Nippon Polyurethane Industry Co., Ltd., “Desmodule” manufactured by Sumika Bayer Urethane Co., Ltd. Or the like.

  The thickness of the surface layer is preferably 20 to 200 μm, more preferably 50 to 100 μm. If it is 20 μm or more, the image quality will be sufficient even for a paper type with surface irregularities. Also, if it is 200 μm or less, it becomes easy to bend due to the weight of the film, the warpage becomes large and the running property becomes unstable, or a crack occurs due to the bending at the roller curvature part for stretching the belt. It won't be easy. The film thickness can be obtained by measuring a cross section with a scanning electron microscope (SEM).

Next, an example of the method for producing the intermediate transfer member of the present invention will be shown.
(Preparation of base layer)
The base layer can be prepared by applying a coating solution containing at least a resin component by a known method such as spiral coating, die coating, roll coating, or spray coating.
That is, for example, while slowly rotating a cylindrical (metal) mold, a coating liquid containing at least a resin component (for example, a coating liquid containing a polyimide resin precursor or a polyamide-imide resin precursor) is applied to a nozzle or a dispenser. A coating film is formed by coating and casting so as to be uniform over the entire outer surface of the cylinder by such a liquid supply device. Thereafter, the rotation speed is increased to a predetermined speed, and when the predetermined speed is reached, the rotation speed is maintained at a constant speed and rotation is continued for a desired time. Next, the temperature is gradually raised while rotating, and the solvent in the coating film is evaporated at about 80 ° C. to 150 ° C. In this process, it is preferable to efficiently circulate and remove atmospheric vapor (such as volatilized solvent). When the self-supporting film is formed, the mold is transferred to a heating furnace (firing furnace) capable of high-temperature treatment, and the temperature is raised stepwise, and finally high-temperature heat treatment (about 250 ° C. to 450 ° C. ( After firing, the product is sufficiently cooled. When a polyimide resin precursor or a polyamideimide resin precursor is used as the resin component, it is sufficiently imidized or polyamideimidized by firing.

(Production of surface layer)
For the surface layer, a coating solution in which at least a polyrotaxane and a curing agent are dissolved in an organic solvent is used. For example, when the curing agent is an isocyanate compound, the equivalent ratio of the polyrotaxane and the curing agent is preferably adjusted to NCO / OH = 1.0 to 1.2. If the equivalence ratio is 1.0 or more, crosslinking is sufficiently performed, and it is not difficult to maintain the shape of the crosslinked product. Moreover, if an equivalent ratio is 1.2 or less, a crosslinked material will not become hard too much and the softness | flexibility as a surface layer will not be impaired.
The surface layer can be produced by applying the coating solution on the base layer, evaporating the solvent by drying, and further curing (crosslinking) the polyrotaxane. The coating may be performed by a known method as in the case of the base layer, and the operation using a cylindrical metal mold is the same. Subsequently, leveling is performed while maintaining a predetermined rotation speed and drying temperature. During the rotation, heating may be performed as necessary.

As the organic solvent used for the surface layer coating solution, it is desirable to select an organic solvent which can dissolve the polyrotaxane and the curing agent and can easily control the amount of the solvent in the coating film within the range of 100 to 10,000 ppm even after drying. Such a solvent preferably has a boiling point of 70 ° C. to 160 ° C., more preferably 100 ° C. to 160 ° C. Specific examples include toluene (boiling point 111 ° C), xylene (boiling point 144 ° C), methyl ethyl ketone (boiling point 80 ° C), ethyl acetate (boiling point 77 ° C), butyl acetate (boiling point 126 ° C), cyclohexanone (boiling point 156 ° C), 2- Examples include heptanone (boiling point 151 ° C.) and 5-methyl-2-hexanone (boiling point 141 ° C.). These may be used singly or in combination of two or more, but cyclohexanone and toluene having high solubility of polyrotaxane are particularly preferred.
Although a coating liquid is based also on the target thickness of the surface layer to form, it is preferable to adjust so that solid content may be 5-50 mass%.

The amount of residual solvent in the surface layer is pre-dried for about 1 to 10 hours at a temperature less than half the boiling point of the solvent (for example, 50 to 70 ° C. in the case of cyclohexanone), and then 30 minutes around the crosslinking temperature of 130 to 200 ° C. It can be controlled by heating again for about 5 hours and adjusting the length of the preliminary drying time. The amount of residual solvent can be measured by, for example, a pyrolysis gas chromatograph (GC-MS). The boiling point of the solvent can be measured by a known method such as JIS K2233-1989.
Although the amount of residual solvent shall be 100-10000 ppm, Preferably it is 500-2000 ppm. By adjusting to the said range, the repair property of the damage | wound created on the surface of the surface layer irrespective of temperature / humidity environment improves markedly. If the amount of residual solvent is less than 100 ppm, scars are hardly repaired. On the other hand, if it exceeds 10000 ppm, it is easily affected by the temperature and humidity environment, and the flexibility of the polyrotaxane at low temperature and low humidity is impaired, so that the wound repairability is lowered. If the preliminary drying is not performed, the residual solvent amount exceeds 10,000 ppm.
The reason for improving the flaw repairability by adjusting the amount of residual solvent in the surface layer is not clear, but the presence of a certain amount of solvent improves the flexibility of the coating and makes the cyclic molecules in the polyrotaxane easier to move. This is probably because

In addition to the above materials, the upper layer coating solution includes a resistance modifier for adjusting electrical characteristics, a flame retardant for imparting flame retardancy, an antioxidant, a reinforcing agent, a filler, and a vulcanization accelerator. Further, a material such as a plasticizer may be appropriately added as necessary. Moreover, you may mix other resin in the range which does not impair the softness | flexibility of a polyrotaxane. Examples of such a resin include a fluororesin, a silicone resin, and an acrylic resin.
Furthermore, an intermediate layer may be introduced into the intermediate transfer member of the present invention as necessary. Examples of the intermediate layer include a primer layer (adhesive layer) for the purpose of improving the adhesion between the base layer and the upper layer, and a rubber layer (elastic layer) for the purpose of improving the unevenness to paper.

[Image forming apparatus]
The image forming apparatus of the present invention includes an image carrier that can form a latent image on which a toner image can be carried, a developing unit that develops the latent image formed on the image carrier with toner, and the development unit that develops the latent image. And a transfer means for secondary transfer of the toner image carried on the intermediate transfer body to the recording medium, and other means appropriately selected as necessary. For example, it has a static elimination means, a cleaning means, a recycling means, a control means, etc. The intermediate transfer member of the present invention described above is used as the intermediate transfer member.
In this case, it is preferable that the image forming apparatus is a full-color image forming apparatus and a plurality of image carriers having developing units for respective colors are arranged in series.

The seamless belt used in the belt constituting unit equipped in the image forming apparatus of the present invention will be described in detail with reference to a schematic diagram of the relevant part. The schematic diagram is an example, and the present invention is not limited to this.
FIG. 3 is a schematic diagram of a main part of an image forming apparatus equipped with the intermediate transfer member of the present invention as a seamless belt.
The intermediate transfer unit 500 including a belt member includes an intermediate transfer belt 501 that is an intermediate transfer member stretched around a plurality of rollers. Around the intermediate transfer belt 501, a secondary transfer bias roller 605 that is a secondary transfer charge applying unit of the secondary transfer unit 600, a belt cleaning brush 504 that is an intermediate transfer member cleaning unit, and a lubricant application of a lubricant application unit. A lubricant application brush 505 or the like which is a member is disposed so as to face each other.

  A position detection mark (not shown) is provided on the outer peripheral surface or inner peripheral surface of the intermediate transfer belt 501. However, on the outer peripheral surface side of the intermediate transfer belt 501, it is necessary to provide a position detection mark so as to avoid the passing area of the belt cleaning brush 504, which may be difficult to arrange. A position detection mark may be provided on the inner peripheral surface side of the intermediate transfer belt 501. An optical sensor 514 serving as a mark detection sensor is provided at a position between the primary transfer bias roller 507 and the belt driving roller 508 where the intermediate transfer belt 501 is bridged.

  The intermediate transfer belt 501 includes a primary transfer bias roller 507, a belt driving roller 508, a belt tension roller 509, a secondary transfer counter roller 510, a cleaning counter roller 511, and a feedback current detection roller 512 serving as a primary transfer charge applying unit. It is stretched. Each roller is formed of a conductive material, and each roller other than the primary transfer bias roller 507 is grounded. The primary transfer bias roller 507 is applied with a transfer bias controlled to a predetermined current or voltage according to the number of superimposed toner images by a primary transfer power source 801 controlled at a constant current or voltage. ing.

The intermediate transfer belt 501 is driven in the arrow direction by a belt driving roller 508 that is driven to rotate in the arrow direction by a drive motor (not shown).
The intermediate transfer belt 501 is usually a semiconductor or an insulator and has a single-layer or multi-layer structure. However, in the present invention, a seamless belt is preferably used, thereby improving durability and forming an excellent image. realizable. Further, the intermediate transfer belt is set to be larger than the maximum sheet passing size in order to superimpose toner images formed on the photosensitive drum 200 as an image carrier.

A secondary transfer bias roller 605 serving as a secondary transfer unit is attached to and separated from a belt outer peripheral surface of the intermediate transfer belt 501 in a portion stretched around the secondary transfer counter roller 510 by a contact / separation mechanism as described later. It is configured to be able to contact and separate. The secondary transfer bias roller 605 is disposed so as to sandwich the transfer paper P, which is a recording medium, between the portion of the intermediate transfer belt 501 stretched around the secondary transfer counter roller 510 and a constant current. A transfer bias having a predetermined current is applied by a secondary transfer power source 802 to be controlled.
The registration roller 610 feeds the transfer sheet P, which is a transfer material, between the secondary transfer bias roller 605 and the intermediate transfer belt 501 stretched around the secondary transfer counter roller 510 at a predetermined timing. The secondary transfer bias roller 605 is in contact with a cleaning blade 608 as a cleaning unit. The cleaning blade 608 is for removing the adhering matter adhering to the surface of the secondary transfer bias roller 605 for cleaning.

  In the color image forming apparatus having such a configuration, when an image forming cycle is started, the photosensitive drum 200 is rotated in a counterclockwise direction indicated by an arrow by a drive motor (not shown), and the BK is placed on the photosensitive drum 200. (Black) toner image formation, C (cyan) toner image formation, M (magenta) toner image formation, and Y (yellow) toner image formation are performed. The intermediate transfer belt 501 is rotated clockwise by the belt driving roller 508 as indicated by an arrow. As the intermediate transfer belt 501 rotates, a primary transfer of the BK toner image, the C toner image, the M toner image, and the Y toner image is performed by a transfer bias by a voltage applied to the primary transfer bias roller 507. Finally, toner images are formed on the intermediate transfer belt 501 in the order of BK, C, M, and Y.

For example, the BK toner image formation is performed as follows.
In FIG. 3, a charging charger 203 uniformly charges the surface of the photosensitive drum 200 to a predetermined potential with a negative charge by corona discharge. The timing is determined based on the belt mark detection signal, and raster exposure using laser light is performed based on the BK color image signal by a writing optical unit (not shown). When this raster image is exposed, the charge proportional to the exposure light amount disappears in the exposed portion of the surface of the photosensitive drum 200 that is initially uniformly charged, and a BK electrostatic latent image is formed. When the negatively charged BK toner on the developing roller of the BK developing unit 231K comes into contact with the BK electrostatic latent image, the toner does not adhere to the remaining portion of the photosensitive drum 200, and the charge is not charged. The toner is attracted to the nonexposed portion, that is, the exposed portion, and a BK toner image similar to the electrostatic latent image is formed.

  The BK toner image formed on the photosensitive drum 200 in this way is primarily transferred onto the belt outer peripheral surface of the intermediate transfer belt 501 that is rotating at a constant speed while being in contact with the photosensitive drum 200. Some untransferred residual toner remaining on the surface of the photoreceptor drum 200 after the primary transfer is cleaned by the photoreceptor cleaning device 201 in preparation for reuse of the photoreceptor drum 200. On the photosensitive drum 200 side, the process proceeds to the C image forming process after the BK image forming process, and reading of C image data by a color scanner starts at a predetermined timing. By writing laser light with the C image data, the photosensitive drum A C electrostatic latent image is formed on the surface of 200.

  Then, after the rear end portion of the previous BK electrostatic latent image passes and before the front end portion of the C electrostatic latent image reaches, the revolver developing unit 230 is rotated, and the C developing machine 231C is developed. The C electrostatic latent image is developed with C toner. Thereafter, the development of the C electrostatic latent image area is continued. When the rear end portion of the C electrostatic latent image passes, the revolver developing unit is rotated in the same manner as in the case of the previous BK developing machine 231K, and the next The M developing machine 231M is moved to the developing position. This is also completed before the leading edge of the next Y electrostatic latent image reaches the developing position. The image forming process for M and Y is not described because the operations of reading color image data, forming an electrostatic latent image, and developing are the same as those of the above-described BK and C processes. Reference numeral 231Y denotes a Y developing machine.

The BK, C, M, and Y toner images sequentially formed on the photosensitive drum 200 in this way are sequentially aligned on the same surface on the intermediate transfer belt 501 and primarily transferred. As a result, a toner image having a maximum of four colors superimposed on the intermediate transfer belt 501 is formed. On the other hand, at the time when the image forming operation is started, the transfer paper P is fed from a paper feed unit such as a transfer paper cassette or a manual feed tray, and is waiting at the nip of the registration roller 610.
The leading edge of the toner image on the intermediate transfer belt 501 hits a secondary transfer portion where a nip is formed by the intermediate transfer belt 501 stretched around the secondary transfer counter roller 510 and the secondary transfer bias roller 605. Sometimes, the registration roller 610 is driven so that the leading edge of the transfer paper P coincides with the leading edge of the toner image, and the transfer paper P is conveyed along the transfer paper guide plate 601, and the transfer paper P, the toner image, and the like. The resist alignment is performed.

  In this way, when the transfer paper P passes through the secondary transfer portion, the four-color superimposed toner image on the intermediate transfer belt 501 is transferred by the transfer bias applied by the secondary transfer power source 802 to the secondary transfer bias roller 605. Are collectively transferred (secondary transfer) onto the transfer paper P. After the transfer paper P is conveyed along the transfer paper guide plate 601 and passed through a portion facing the transfer paper neutralization charger 606 composed of a static elimination needle disposed on the downstream side of the secondary transfer portion, the transfer paper P is discharged. Then, the toner is fed toward the fixing device 270 by the belt conveyance device 210 which is a belt component. Then, after the toner image is melted and fixed at the nip portions of the fixing rollers 271 and 272 of the fixing device 270, the transfer paper P is sent out of the apparatus main body by a discharge roller (not shown) and stacked on a copy tray (not shown) face up. Is done. Note that the fixing device 270 may be configured to include a belt component if necessary.

On the other hand, the surface of the photosensitive drum 200 after the belt transfer is cleaned by the photosensitive member cleaning device 201 and is uniformly discharged by the discharging lamp 202. Further, residual toner remaining on the outer peripheral surface of the intermediate transfer belt 501 after the toner image is secondarily transferred to the transfer paper P is cleaned by the belt cleaning brush 504. The belt cleaning brush 504 is configured to contact and separate at a predetermined timing with respect to the belt outer peripheral surface of the intermediate transfer belt 501 by a cleaning member separating and contacting mechanism (not shown).
On the upstream side of the belt cleaning brush 504 in the movement direction of the intermediate transfer belt 501, a toner seal member 502 that is in contact with and away from the outer peripheral surface of the intermediate transfer belt 501 is provided. The toner seal member 502 receives the falling toner that has dropped from the belt cleaning brush 504 during the cleaning of the residual toner, and prevents the falling toner from being scattered on the transfer path of the transfer paper P. The toner seal member 502 is brought into contact with and separated from the belt outer peripheral surface of the intermediate transfer belt 501 together with the belt cleaning brush 504 by the cleaning member separating and contacting mechanism.

  The lubricant 506 scraped by the lubricant application brush 505 is applied to the outer peripheral surface of the intermediate transfer belt 501 from which the residual toner has been removed in this way. The lubricant 506 is made of, for example, a solid body such as zinc stearate, and is disposed so as to come into contact with the lubricant application brush 505. Further, residual charges remaining on the outer peripheral surface of the intermediate transfer belt 501 are removed by a neutralizing bias applied by a belt neutralizing brush (not shown) that is in contact with the outer peripheral surface of the intermediate transfer belt 501. Here, the lubricant application brush 505 and the belt neutralizing brush are brought into contact with and separated from the belt outer peripheral surface of the intermediate transfer belt 501 at a predetermined timing by respective contact and separation mechanisms (not shown). .

Here, at the time of repeat copy, the operation of the color scanner and the image formation on the photosensitive drum 200 are performed at a predetermined timing following the first color (Y) image formation process of the first sheet and the first color of the second sheet. The process proceeds to the (BK) image forming process. Further, the intermediate transfer belt 501 has a second BK toner in an area cleaned by the belt cleaning brush 504 on the outer peripheral surface of the belt following the batch transfer process of the first four-color superimposed toner image to the transfer paper. The image is first transferred. After that, the operation is the same as the first sheet. The above is a copy mode for obtaining a four-color full-color copy. In the three-color copy mode and the two-color copy mode, the same operation as described above is performed for the designated color and the number of times. In the case of the single color copy mode, only the predetermined color developing machine of the revolver developing unit 230 is set in the developing operation state until the predetermined number of sheets is completed, and the belt cleaning blade 504 is kept in contact with the intermediate transfer belt 501. The copy operation is performed in the state.
In FIG. 3, reference numeral 70 denotes a static elimination roller, 204 denotes a potential sensor, 205 denotes an image density sensor, 503 denotes a charging charger, 513 denotes a toner image, and L denotes laser light (emitted from laser exposure means).

In the above embodiment, the image forming apparatus provided with only one photosensitive drum has been described. However, the present invention includes, for example, a plurality of photosensitive drums as illustrated in a schematic diagram of a main part in FIG. The present invention can also be applied to an image forming apparatus arranged side by side along one intermediate transfer belt formed of a seamless belt.
The schematic diagram of the main part of FIG. 4 shows an example of a full-color image forming apparatus in which a plurality of image carriers are arranged in parallel along the intermediate transfer belt of the present invention. That is, FIG. 4 shows four photosensitive drums 21BK, 21Y, 21M, and four photosensitive drums 21BK for forming toner images of four different colors [black (BK), yellow (Y), magenta (M), cyan (C)]. An example of a 4-drum type digital color printer provided with 21C is shown.

  In FIG. 4, the printer main body 10 includes an image writing unit 12, an image forming unit 13, and a paper feeding unit 14 for performing color image formation by electrophotography. Then, based on the image signal, the image processing unit performs image processing to convert the image forming BK, M, Y, and C color signals, and transmits them to the image writing unit 12. The image writing unit 12 is a laser scanning optical system including, for example, a laser light source, a deflector such as a rotary polygon mirror, a scanning imaging optical system, and a mirror group. The image writing unit 12 includes four writing optical paths corresponding to the color signals described above. And image writing corresponding to each color signal is performed on image carriers (photosensitive drums) 21BK, 21M, 21Y, and 21C provided for each color of the image forming unit 13.

  The image forming unit 13 includes photosensitive drums 21BK, 21M, 21Y, and 21C that are image carriers for BK, M, Y, and C. An OPC photoreceptor is usually used as the photoreceptor for each color. Around the photosensitive drums 21BK, 21M, 21Y, and 21C, there are a charging device, a laser beam exposure unit from the writing unit 12, and developing devices 20BK, 20M, and 20Y for the colors BK, M, Y, and C. 20C, primary transfer bias rollers 23BK, 23M, 23Y, and 23C as primary transfer means, a cleaning device (not shown), and a photosensitive member discharging device not shown. The developing devices 20BK, 20M, 20Y, and 20C use a two-component magnetic brush developing method. The intermediate transfer belt 22, which is a belt component, is interposed between the photosensitive drums 21BK, 21M, 21Y, and 21C and the primary transfer bias rollers 23BK, 23M, 23Y, and 23C, and is disposed on the photosensitive drums. The formed toner images of respective colors are sequentially superimposed and transferred.

  On the other hand, the transfer paper P is fed from the paper feed unit 14 and then carried by the transfer conveyance belt 50 which is a belt component via the registration roller 16. When the intermediate transfer belt 22 and the transfer conveying belt 50 come into contact, the toner image transferred onto the intermediate transfer belt 22 is subjected to secondary transfer (collective transfer) by a secondary transfer bias roller 60 as a secondary transfer unit. Is done. As a result, a color image is formed on the transfer paper P. The transfer paper P on which the color image is formed is conveyed to the fixing device 15 by the transfer conveyance belt 50, and after the image is fixed, it is discharged out of the printer main body.

  Residual toner remaining on the intermediate transfer belt 22 without being transferred during the secondary transfer is removed from the intermediate transfer belt 22 by the belt cleaning member 25. A lubricant application device 27 is disposed on the downstream side of the belt cleaning member 25. The lubricant application device 27 includes a solid lubricant and a conductive brush that rubs against the intermediate transfer belt 22 to apply the solid lubricant. The conductive brush is always in contact with the intermediate transfer belt 22 and applies a solid lubricant to the intermediate transfer belt 22. The solid lubricant has an effect of improving the cleaning property of the intermediate transfer belt 22, preventing the occurrence of filming, and improving the durability. In FIG. 4, reference numeral 26 denotes a driving roller, and 70 denotes a bias roller.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited by these examples, and these examples are appropriately selected without departing from the gist of the present invention. Modifications are also included in the present invention. The amount of residual solvent in the surface layer of the intermediate transfer belt was measured at an arbitrary location with a pyrolysis gas chromatograph mass spectrometer (GC-MS), and the film thickness of the intermediate transfer belt was measured at 10 arbitrary cross sections. It is the average value of the value which measured the film thickness of this with the scanning electron microscope (SEM).

<Example 1>
An intermediate transfer belt A, which is one form of the intermediate transfer member, was produced by the following procedure.

[Preparation of base layer coating solution A]
A polyimide varnish containing a polyamic acid as a main component of a polyimide resin precursor (mixture of solid content ratio of U-varnish A and U-varnish S 6: 4 (mass ratio); manufactured by Ube Industries Co., Ltd.) was previously N- A dispersion of carbon black (Special Black 4; manufactured by Orion Engineered Carbons) dispersed in methyl-2-pyrrolidone was mixed and stirred so that the carbon black content was 17% by mass of the polyamic acid solid content. A base layer coating solution A was prepared.

[Preparation of polyimide base layer belt A]
Next, using a metallic cylindrical support whose outer surface has an outer diameter of 375 mm and a length of 360 mm, which has been roughened by blasting, as a mold, coating the base layer while rotating this cylindrical mold at 50 rpm (times / minute) Liquid A was applied with a dispenser so as to be uniformly cast on the outer surface of the cylinder. When the predetermined amount was completely poured and the coating film spread evenly, the number of revolutions was increased to 100 rpm, introduced into a hot air circulating dryer, gradually heated to 110 ° C. and heated for 60 minutes. The temperature was further raised and heated at 200 ° C. for 20 minutes, and then the rotation was stopped and gradually cooled to take out the cylindrical mold on which the molded film was formed. This was introduced into a heating furnace (firing furnace) capable of high-temperature treatment, heated up to 360 ° C. stepwise, and heat-treated (firing) for 60 minutes. Thereafter, it was sufficiently cooled to obtain a cylindrical support on which a polyimide base layer belt A having a film thickness of 60 μm was formed.

[Preparation of surface coating liquid A]
Polyrotaxane (CAS No. 928045-45-8), which is an α-cyclodextrin having a polyethylene glycol as a linear molecule, an adamantane group as a blocking group, and a hydroxypropyl group as a cyclic molecule (Celum Superpolymer SH3400P; Advanced Soft Materials) Made in cyclohexanone (boiling point 156 ° C.), hexamethylene diisocyanate polyisocyanate (Duranate TPA-B80E; manufactured by Asahi Kasei Chemical Co., Ltd.) [block isocyanate] is added, and NCO (reactive group of curing agent) / OH was adjusted to an equivalent ratio of 1.05 to prepare a surface layer coating solution A having a total solid content of 30% by mass.

[Preparation of Intermediate Transfer Belt A]
While rotating the cylindrical support on which the polyimide base belt A is formed, the surface coating liquid A is continuously discharged from the nozzle onto the polyimide base layer and moved to the axial method of the cylindrical support to be spiral. Coated. The coating amount was such that the final thickness of the surface layer was 30 μm. Next, it is put into a hot air circulating dryer heated to 70 ° C. while rotating the cylindrical support, preliminarily dried as it is for 180 minutes, and then heated to 150 ° C. at a rate of temperature increase of 4 ° C./min for 90 minutes. As a result, an intermediate transfer belt A was obtained.
The amount of residual solvent on the surface layer of the intermediate transfer belt A was 1800 ppm.

<Example 2>
An intermediate transfer belt B was obtained in the same manner as in Example 1 except that the solvent was changed to diisobutyl ketone (boiling point 168 ° C.).
The residual solvent amount on the surface layer of the intermediate transfer belt B was 8200 ppm.

<Example 3>
An intermediate transfer belt C was obtained in the same manner as in Example 1 except that the solvent was changed to toluene (boiling point 111 ° C.) and the preheating temperature was changed to 50 ° C.
The residual solvent amount on the surface layer of the intermediate transfer belt C was 730 ppm.

<Example 4>
An intermediate transfer belt D was obtained in the same manner as in Example 1 except that the solvent was changed to methyl ethyl ketone (boiling point 80 ° C.), the preliminary drying temperature was changed to 40 ° C., and the preliminary drying time was changed to 120 minutes.
The residual solvent amount on the surface layer of the intermediate transfer belt D was 120 ppm.

<Example 5>
An intermediate transfer belt E was obtained in the same manner as in Example 1 except that the coating conditions were changed so that the final surface layer thickness was 180 μm.
The amount of residual solvent on the surface layer of the intermediate transfer belt E was 2800 ppm.

<Example 6>
An intermediate transfer belt F was obtained in the same manner as in Example 1 except that the coating conditions were changed so that the final surface layer thickness was 10 μm.
The amount of residual solvent on the surface layer of the intermediate transfer belt F was 200 ppm.

<Example 7>
An intermediate transfer belt G was obtained in the same manner as in Example 1 except that the coating conditions were changed so that the final surface layer thickness was 300 μm and the preliminary drying time was changed to 300 minutes.
The amount of residual solvent on the surface layer of the intermediate transfer belt G was 7000 ppm.

<Example 8>
In the same manner as in Example 1, except that “Duranate TPA-B80E” as the curing agent in Example 1 was changed to “Takenate D-177N (manufactured by Mitsui Chemicals)” which is a hexamethylene diisocyanate polyisocyanate. A transfer belt H was obtained.
The amount of residual solvent on the surface layer of the intermediate transfer belt H was 550 ppm.

<Comparative Example 1>
An intermediate transfer belt I was obtained in the same manner as in Example 1 except that the preliminary drying was not performed.
The residual solvent amount on the surface layer of the intermediate transfer belt I was 14600 ppm.

<Comparative example 2>
An intermediate transfer belt J was obtained in the same manner as in Example 1 except that the preliminary drying time was changed to 480 minutes. The residual solvent amount on the surface layer of the intermediate transfer belt J was 50 ppm.

[Evaluation of characteristics]
The intermediate transfer belts A to J were mounted on an image MPC7501 (manufactured by Ricoh) (corresponding to claims 6 and 7) which is an image forming apparatus having the structure shown in FIGS.
The paper used was POD gloss coated paper (Oji Paper). The POD gloss coated paper is a thick paper having a coated surface, and the belt is easily damaged at the edge of the paper when the paper is passed.
First, 10,000 black halftone images were passed through A4 size POD gloss coated paper (output in A4 portrait), and it was confirmed that vertical stripes were scratched on the intermediate transfer belt by the edge of the paper. .
Then, immediately after that and after standing for 1 hour, a black halftone image was output with A3 size POD gloss coated paper, and the influence of the scratches on the intermediate transfer belt on the image was confirmed.
These tests were performed at 10 ° C. 15% RH and 23 ° C. 50% RH, respectively.
Evaluation was performed according to the following criteria. The results are shown in Table 1.
〔Evaluation criteria〕
○: No vertical stripe image (wound repair completed)
△: A vertical streak image can be seen slightly but usable level (incomplete wound repair)
×: Vertical streaks appear clearly in the image and cannot be used (without repairing scratches)

From the above results, it can be seen that the intermediate transfer belts of Examples 1 to 8 in which the residual solvent amount is controlled in the range of 100 to 10000 ppm have high scratch repairability independent of the temperature and humidity environment.
On the other hand, if the residual solvent amount is more than 10000 ppm as in Comparative Example 1, there is no scratch repairability in a low-temperature and low-humidity environment, and if the residual solvent amount is less than 100 ppm as in Comparative Example 2, It can be seen that there is no repairability.

(Reference in FIG. 1)
11 base layer 12 surface layer

(Reference in FIG. 2)
1 Polyrotaxane 2 Linear molecule 3 Cyclic molecule 3A Lipophilic modifying group 4 Blocking group

(Reference in FIG. 3)
P Transfer paper L Laser light 70 Static elimination roller 80 Ground roller 200 Photosensitive drum 201 Photosensitive drum cleaning device 202 Static elimination lamp 203 Charger charger 204 Potential sensor 205 Image density detection sensor 210 Belt conveying device 230 Revolver developing unit 231Y Y developing device 231K BK development Machine 231C C developing machine 231M M developing machine 270 fixing device 271 fixing roller 272 fixing roller 500 intermediate transfer unit 501 intermediate transfer belt 502 toner seal member 503 charging charger 504 belt cleaning brush 505 lubricant application brush 506 lubricant 507 primary transfer bias Roller 508 Belt drive roller 509 Belt tension roller 510 Secondary transfer counter roller 511 Cleaning counter roller 512 Feedback Current detection roller 513 the toner image 514 optical sensor 600 the secondary transfer unit 601 transfer sheet guide plate 605 secondary transfer bias roller 606 transfer paper discharger 608 cleaning blade 610 a registration roller 801 primary transfer power supply 802 secondary transfer power supply

(Reference in FIG. 4)
P transfer paper 10 printer main body 12 image writing unit 13 image forming unit 14 paper feeding unit 15 fixing device 16 registration roller 20BK BK developing device 20M M developing device 20Y Y developing device 20C C developing device 21BK BK photosensitive drum 21M M photosensitive member Drum 21Y Y photosensitive drum 21C C photosensitive drum 22 Intermediate transfer belt 23BK BK primary transfer bias roller 23M M primary transfer bias roller 23Y Y primary transfer bias roller 23C C primary transfer bias roller 25 Belt cleaning brush 26 Drive roller 27 Lubricant coating Device 50 Transfer conveyance belt 60 Secondary transfer bias roller 70 Static elimination roller

JP 2013-29632 A Patent No. 4840038 Japanese Patent No. 5641523

Claims (7)

An intermediate transfer member satisfying the following requirements (1) to (4):
(1) It has a base layer and a surface layer provided thereon.
(2) The surface layer contains a crosslinked product obtained by curing polyrotaxane with a curing agent.
(3) The polyrotaxane includes at least a cyclic molecule, a linear molecule penetrating through the cyclic molecule, and a blocking group that prevents elimination of the cyclic molecule bonded to both ends of the linear molecule. Have
(4) The surface layer contains 100 to 10,000 ppm of residual solvent.   The intermediate transfer member according to claim 1, wherein the boiling point of the residual solvent is 100 ° C. to 160 ° C.   The intermediate transfer member according to claim 1, wherein the surface layer has a thickness of 20 to 200 μm.   The intermediate transfer member according to claim 1, wherein the form is a seamless belt.   The intermediate transfer member according to any one of claims 1 to 4, wherein a base layer material is applied to an outer surface of a cylindrical mold and dried to form a base layer, and then a surface layer is laminated thereon. Method.   An image carrier on which a latent image is formed and capable of carrying a toner image, a developing unit that develops the latent image formed on the image carrier with toner, and a toner image developed by the developing unit are primarily transferred. An intermediate transfer member according to any one of claims 1 to 4, further comprising: an intermediate transfer member; and a transfer unit that secondarily transfers a toner image carried on the intermediate transfer member to a recording medium. An image forming apparatus, comprising:   The image forming apparatus according to claim 6, wherein a plurality of image carriers having developing means for each color are arranged in series to form a full color image.