JP5302845B2 - Endless belt for electrophotographic equipment - Google Patents

Description

  The present invention relates to an endless belt for electrophotographic equipment, and particularly suitable as an intermediate transfer belt or the like in electrophotographic equipment using electrophotographic technology such as full color LBP (laser beam printer) and full color PPC (plain paper copier). The present invention relates to an endless belt for electrophotographic equipment that can be used.

  Conventionally, in an electrophotographic apparatus using electrophotographic technology such as full color LBP and full color PPC, an endless belt having a conductivity (seamless belt) has been used for various purposes. For example, for an electrophotographic apparatus that plays a role of primarily transferring a toner image formed on a photoreceptor (photosensitive drum) onto a belt surface and then secondary-transferring the toner image on the belt surface to a printed material such as paper. As an endless belt, an intermediate transfer belt is widely known.

  For such an intermediate transfer belt, in order to print a target image or the like on a printing material such as paper with an excellent image quality, it is a matter of course that excellent transferability is required. Surface smoothness is required so that toner does not remain on the belt surface by processing the subsequent belt surface with a predetermined cleaning mechanism (such as a cleaning blade). In recent years, electrophotographic equipment has been required to increase the printing speed and the life of the equipment, and to an intermediate transfer belt (an endless belt for electrophotographic equipment) which is a member of electrophotographic equipment. However, there is a demand for a device that can endure high-speed operation of the device and has a long life, that is, durability that is higher than that of the conventional device.

  Under such circumstances, development of an endless belt for an electrophotographic apparatus that can be advantageously used as an intermediate transfer belt is underway, and conventionally, belts having various configurations have been proposed. For example, in Patent Document 1 (Japanese Patent Laid-Open No. 2000-305389), in an endless belt having a heat-resistant elastic layer on the surface of a base film mainly composed of a heat-resistant resin, the surface roughness Rz of the base film is 0.1 μm. An endless belt for an electrophotographic apparatus characterized by a thickness of ˜50 μm is clearly shown. Therefore, such an endless belt for an electrophotographic apparatus has a sufficient shear resistance due to an anchor effect at the interface so that the interface peeling can be prevented even if the belt driving force from the driving roll is transmitted from the heat resistant elastic layer side to the base film. Since it is bound, it is said that the endless belt can be smoothly run only by driving the fixing roll.

  However, the inventor et al. Examined the endless belt proposed in Patent Document 1 and other conventional endless belts for electrophotographic equipment in detail. It has been found that the surface of the belt and / or the durability of the belt is still not sufficient.

  In addition, in the endless belt proposed in Patent Document 1 described above, a cylindrical mold whose inner surface is roughened by a bullet travel coating method or a centrifugal molding method is used as the roughness of the base film surface. Alternatively, the surface of the molded endless belt substrate is subjected to sandblast treatment, sputter etching treatment, corona discharge treatment, and the like. However, all of the methods described therein have problems such as requiring a predetermined mold and apparatus and increasing the number of processes in many cases.

JP 2000-305389 A

  Here, the present invention has been made in the background of such circumstances, and the problem to be solved is an electrophotography that has excellent durability and excellent cleaning properties on the surface. It is to provide an endless belt for equipment.

  In order to advantageously solve such a problem, the present invention provides an endless belt for an electrophotographic apparatus in which an elastic layer is provided on the surface of a base layer having an average waviness height of 0.5 to 4.0 μm. The gist of the endless belt for electrophotographic equipment is characterized in that the surface waviness pitch is 0.5 to 3.0 mm and the average waviness height is 0.7 μm or less. It is.

In addition, in such an endless belt for electrophotographic equipment according to the present invention, the following can be cited as a preferred embodiment.
1) The base layer is formed according to a dispenser coating method using a liquid base layer material mainly composed of a synthetic resin material, and the elastic layer is a liquid elastic layer mainly composed of a rubber material. The material is formed according to the dispenser coating method.
2) The base layer material is mainly composed of a polyimide resin or a polyamideimide resin.
3) The elastic layer material is mainly composed of at least one of acrylonitrile-butadiene rubber, butadiene rubber, styrene-butadiene rubber, butyl rubber, and chloroprene rubber.
4) The viscosity of the base layer material is 1000 to 50000 mPa · s.
5) The elastic layer material has a viscosity of 1000 to 70000 mPa · s.
6) The thickness of the base layer is 50 to 200 μm.

  As described above, the endless belt for an electrophotographic apparatus according to the present invention is provided with an elastic layer on the surface of the base layer in which the average undulation height is within a predetermined range, and the undulation pitch and the average undulation height of the surface. Are configured to be within a predetermined range. By adopting such a configuration, in the endless belt for an electrophotographic apparatus of the present invention, delamination between the base layer and the elastic layer is effectively suppressed, so that the durability of the belt is advantageous. In addition, since the belt surface is effectively smoothed, even if toner remains on the belt surface after the secondary transfer to the substrate, a predetermined cleaning mechanism is used. Therefore, it is easy to remove the residual toner, and excellent cleaning properties are exhibited.

  In addition, the endless belt for an electrophotographic apparatus that exhibits such excellent characteristics is, in particular, 1) a base layer is formed according to a dispenser coating method using a liquid base layer material mainly composed of a synthetic resin material, and then 2) It can be advantageously manufactured by forming the elastic layer according to a dispenser coating method using a liquid elastic layer material mainly composed of a rubber material. In the dispenser coating method for producing the base layer and the elastic layer, it is not necessary to use a mold having a specific shape, and by appropriately setting the coating conditions, the shapes of the base layer surface and the belt surface ( (Swell shape) can be within the scope of the present invention, and it is not necessary to perform a separate process required for the belt described in Patent Document 1 or the like, and the manufacturing cost can be kept low. It is squeezed.

It is a section explanatory view showing an example of an endless belt for electrophotographic equipment according to the present invention. It is a fragmentary sectional view showing an example of an endless belt for electrophotographic equipment according to the present invention. It is explanatory drawing which shows an example of the dispenser coating method at the time of manufacturing the endless belt for electrophotographic apparatuses according to this invention.

  Hereinafter, the present invention will be described more specifically with reference to the drawings as appropriate.

  FIG. 1 is an explanatory cross-sectional view of an example of an endless belt for electrophotographic equipment (hereinafter also simply referred to as a belt) according to the present invention, cut along a plane parallel to the axial direction of the belt and including the axial center. These are the partial explanatory drawings of the cross section cut | disconnected by the surface (AA surface in FIG. 1) orthogonal to the axial direction of a belt. As is apparent from FIGS. 1 and 2, the endless belt 2 for electrophotographic equipment of the present invention is provided with an elastic layer 6 made of a predetermined crosslinked rubber on the surface of the base layer 4.

  And, in the endless belt 2 for electrophotographic equipment of the present invention, the first feature exists where the average undulation height of the surface of the base layer 4 is 0.5 to 4.0 μm. is there. Thus, by making the average waviness height on the surface of the base layer 4 within a predetermined range, delamination between the elastic layer 6 and the endless belt 2 for electrophotographic equipment can be effectively suppressed. It is advantageously improved.

  Here, when the average waviness height of the base layer 4 is less than 0.5 μm, the adhesion strength in the axial direction of the belt 2 may be insufficient, and the durability of the belt may not be sufficiently secured. If the average waviness height of the base layer 4 exceeds 4.0 μm, the smoothness of the belt surface may be deteriorated and sufficient cleaning properties may not be exhibited.

  In addition, the average waviness height in the present specification and claims is the waviness curve measured and calculated in accordance with JIS-B-0601: 2001 in the axial direction of the surface (or belt surface) of the base layer 4. The average height of the elements: Wc, and the waviness pitch described later are the average value of the distance between the mountains in the waviness curve measured in accordance with JIS-B-0601: 2001 in the axial direction of the belt surface. , Respectively.

  The base layer 4 having such a predetermined swell average height is formed using a base layer material mainly composed of a synthetic resin material. As the synthetic resin material as the main component of the base layer material, those conventionally used in endless belts for electrophotographic equipment, for example, polyimide resin, polyamideimide resin, polyethersulfone resin, fluorine resin, polycarbonate resin, etc. Any of these may be used alone or in combination of two or more, but among them, a polyimide resin and / or a polyamideimide resin exhibiting excellent rigidity and the like are particularly advantageous in the present invention. Used for.

  In addition to the synthetic resin material as described above, additives such as a conductive agent, a flame retardant, a filler such as calcium carbonate, and a leveling agent (release agent) are appropriately blended in the base layer material as necessary. Is done. In addition, about a electrically conductive agent and a flame retardant, the thing similar to what is mentioned later can be used.

The conductive agent blended in the base layer material is not particularly limited. For example, conductive powder such as carbon black and graphite, metal powder such as aluminum powder and stainless powder, conductive zinc oxide (c-ZnO) , Conductive titanium oxide (c-TiO ₂ ), conductive iron oxide (c-Fe ₃ O ₄ ), conductive tin oxide (c-SnO ₂ ) and other conductive metal oxides, quaternary ammonium salts, phosphorus Ionic conductive agents such as acid esters, sulfonates, aliphatic polyhydric alcohols and aliphatic alcohol sulfate salts can be used. Moreover, as a flame retardant mix | blended with the material for base layers, an inorganic type flame retardant, an organic type flame retardant, etc. can be illustrated.

  Preparation of the base layer material using the above-described synthetic resin material or the like is performed according to the belt manufacturing method. For example, when the base layer 4 is formed according to the dispenser coating method described later, the above-described synthetic resin material is replaced with N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide (DMAc), toluene, A liquid base layer material is prepared by adding to and mixing with an organic solvent such as acetone. When the base layer 4 is formed according to the dispenser coating method described later, if the viscosity of the material for the base layer is too large, the average swell height may exceed 4.0 μm, while if the viscosity is too low, the swell average Since the height may be less than 0.5 μm and the base layer material is likely to sag, it may be difficult to make the thickness of the base layer and thus the entire belt uniform. The viscosity of is adjusted to 1000 to 50000 mPa · s.

  A method for forming the base layer 4 using the prepared base layer material is a conventionally known method, and the average undulation height on the surface of the base layer 4 is within a predetermined range (0.5 to 4.0 μm). Any method can be used as long as it can be used. The thickness of the base layer 4 formed according to any one of these methods is appropriately determined according to characteristics required for the endless belt 2 for electrophotographic equipment, but is usually 50 to 200 μm.

  In the endless belt 2 for electrophotographic equipment according to the present invention as shown in FIGS. 1 and 2, a predetermined amount is formed on the surface of the base layer 4 formed using the base layer material as described above. An elastic layer 6 made of a crosslinked rubber is provided, and the undulation pitch is 0.5 to 3.0 mm on the surface of the belt 2 (the surface of the elastic layer 6 in the belt 2 shown in FIGS. 1 and 2). In addition, the second feature exists where the mean undulation height is 0.7 μm or less. Thus, by defining the waviness pitch and waviness average height on the surface of the belt 2 (the surface of the elastic layer 6), the endless belt 2 for electrophotographic equipment of the present invention ensures the smoothness of the belt surface, Thus, excellent cleaning properties are exhibited. That is, when the waviness pitch on the surface of the belt 2 is less than 0.5 mm or exceeds 3.0 mm, and further when the average waviness height on the surface of the belt 2 exceeds 0.7 μm, excellent cleaning properties are obtained. Therefore, the smoothness that can exhibit the above cannot be ensured.

  When such an elastic layer 6 is formed on the surface of the base layer 4, generally, a material (elastic layer material) formed by blending a rubber material, a curing agent (crosslinking agent), and various additives as necessary is used. Used.

  First, as the rubber material as the main component of the elastic layer material, any rubber material can be used as long as it is conventionally used when producing an elastic layer of an endless belt for electrophotographic equipment. Is possible. Among them, acrylonitrile-butadiene rubber (NBR), butadiene rubber (BR), styrene-butadiene rubber (SBR), butyl rubber (IIR) or chloroprene rubber (CR) can be advantageously used. These various rubber materials can be used alone or in combination of two or more.

  Moreover, even if it exists in the hardening | curing agent (crosslinking agent) used in order to harden (crosslink) these rubber materials, all conventionally well-known things can be used, for example, sulfur, a resin crosslinking agent, etc. are mentioned. I can do it.

  Furthermore, when producing the elastic layer 6 of the endless belt 2 for electrophotographic equipment of the present invention, various additives are added to the elastic layer material in addition to the rubber material and the curing agent (crosslinking agent) described above. It mix | blends suitably according to the addition objective.

  For example, in order to impart conductivity to the endless belt 2 for electrophotographic equipment, a conductive agent is generally blended in the elastic layer material. Such conductive agents include not only carbon black and metal oxides that have been widely used in the past, but also quaternary ammonium salts, phosphate esters, sulfonates, aliphatic polyhydric alcohols, aliphatic alcohol sulfate salts, and the like. An ionic conductive agent etc. can be mentioned, and especially an ionic conductive agent is used advantageously. The conductive agent is blended in the elastic layer material in a quantitative ratio that can exhibit the electrical characteristics required for the belt 2.

  In addition, recently, since flame resistance is also required for endless belts for electrophotographic equipment, it is preferable to add a flame retardant to the elastic layer material. In general, flame retardants for imparting flame retardancy to crosslinked rubber are roughly classified into inorganic flame retardants (antimony and metal hydroxides) and organic flame retardants. Even a flame retardant can be used. Examples of the inorganic flame retardant used in the present invention include antimony flame retardants such as antimony trioxide and antimony pentoxide, metal hydroxide flame retardants such as magnesium hydroxide and aluminum hydroxide, and the like. I can do it. Examples of organic flame retardants include a) decabromodiphenyl ether, b) tetrabromobisphenol-A and derivatives thereof, c) polybenzene ring compounds such as bis (pentabromophenyl) ethane, d) brominated polystyrene, and the like. Brominated flame retardants such as polybrominated styrene, e) aromatic phosphate esters, f) aromatic condensed phosphate esters, g) halogen-containing phosphate esters, h) halogen-containing condensed phosphate esters, i) Phosphorus flame retardants such as phosphazene derivatives can be mentioned. These flame retardants can be used alone or in combination of two or more. In addition, the usage-amount of a flame retardant is suitably determined within the range which does not inhibit the objective of this invention, and is mix | blended with the material for elastic layers.

  In addition, various additives such as a leveling agent can be blended within the scope of the present invention.

  In addition, preparation of the elastic layer material using the rubber material described above is appropriately performed according to the belt manufacturing method, similarly to the preparation of the base layer material. For example, when the elastic layer 6 is produced according to the dispenser coating method described below, the above rubber material or the like is used as cyclohexanone, N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide (DMAc). ), An elastic solvent material such as toluene or acetone is added and mixed to prepare a liquid elastic layer material. When forming the elastic layer 6 according to the dispenser coating method described later, if the viscosity of the elastic layer material is too large, the swell average height may exceed 0.7 μm, while if the viscosity is too small, Since the elastic layer material tends to sag and it may be difficult to make the thickness of the elastic layer and thus the entire belt uniform, the elastic layer material usually has a viscosity of 1000 to 70000 mPa · s. Prepared.

  The method for forming the elastic layer 6 using the prepared elastic layer material is a conventionally known method, in which the undulation pitch and the average undulation height on the surface of the elastic layer 6 are set within a predetermined range. Any method can be used as long as it can be used. The thickness of the elastic layer 6 formed according to any of these methods is appropriately determined according to the characteristics required for the endless belt 2 for electrophotographic equipment, but is usually 100 to 1000 μm.

  As described above, the base layer 4 and the elastic layer 6 constituting the endless belt 2 for an electrophotographic apparatus of the present invention can each be produced according to various conventionally known methods. It is preferable to produce the base layer 4 and the elastic layer 6 in accordance with the dispenser coating method described in (1). This is because, by appropriately adopting various conditions in the later-described dispenser coating method, the average waviness height of the surface of the base layer 4, the waviness pitch and the average waviness height of the surface of the elastic layer 6 are respectively within the scope of the present invention. This is because it is easy to be inside. Hereinafter, the case where the endless belt 2 for electrophotographic equipment of the present invention is manufactured according to the dispenser coating method will be described in detail.

  First, it has a cylindrical or columnar base body that can rotate around its axis, two nozzles (first nozzle, second nozzle), and two material tanks (first material tank, second material tank). Prepare the dispenser. The two nozzles (the first nozzle and the second nozzle) are arranged so as to be movable along the axial direction of the base at a position close to the outer peripheral surface of the base. Meanwhile, a liquid base layer material and a liquid elastic layer material are prepared, and the base layer material is accommodated in the first material tank and the elastic layer material is accommodated in the second material tank. The outer diameter of the substrate is determined according to the specifications of the endless belt 2 for electrophotographic equipment finally obtained, and is usually 30 to 350 mm. The nozzle diameter of each nozzle affects the average swell height of the base layer (elastic layer), and generally the nozzle diameter is 0.5 to 2.0 mm.

  Next, as shown in FIG. 3, the cylindrical base 10 is rotated about the axis in a vertical state. In a state where the substrate 10 is rotated, the built-in base layer material 12 is sent from the first material tank 14 containing the base layer material 12 to the first nozzle 16, and the outer periphery of the substrate 10 is transmitted from the first nozzle 16. The base layer material 12 is discharged onto the surface. Simultaneously with the discharge of the base layer material 12, the first nozzle 16 is moved at a constant speed along the axial direction of the substrate 10. As a result, a band (coating film) having a constant width made of the base layer material 12 is formed on the outer peripheral surface of the base 10 in a spiral shape, and the first nozzle 16 is moved from one end side of the base 10. By moving to the other end side, an entire coating film composed of a continuous spiral coating film of the base layer material 12 is formed on the outer peripheral surface of the substrate 10. The spiral coating film of the base layer material 12 is usually formed on the outer peripheral surface of the substrate 10 so that a predetermined interval is generated between the upper band and the lower band.

  First, the base layer 4 is formed by subjecting the entire coating film made of the base layer material 12 thus formed on the outer peripheral surface of the substrate 10 to heat treatment under a predetermined condition and removing the organic solvent. It is formed.

  Next, the base body 10 on which the base layer 4 is formed on the outer peripheral surface is rotated around the axis in the same manner as before (as shown in FIG. 3). With the base 10 rotated about the axis, the built-in elastic layer material is brought close to the outer peripheral surface of the base 10 (the surface of the formed base layer 4) from the second material tank containing the elastic layer material. The elastic layer material is discharged from the second nozzle to the base layer 4 on the outer peripheral surface of the substrate 10. Simultaneously with the discharge of the elastic layer material, the second nozzle is moved at a constant speed along the axial direction of the substrate 10. As a result, a band (coating film) having a constant width made of an elastic layer material is formed on the surface of the base layer 4 formed on the outer peripheral surface of the substrate 10 in a spiral shape. When the base layer 4 on the outer peripheral surface of the substrate 10 is moved from one end side to the other end side, the entire coating film made of a continuous spiral coating film of the elastic layer material is formed on the surface thereof. It is formed.

  And the hardening (crosslinking) process according to the hardening | curing agent (crosslinking agent) contained in the material for elastic layers with respect to the obtained whole coating film, specifically, heating, ultraviolet irradiation, electron beam irradiation, etc. are given. As a result, the endless belt 2 for an electrophotographic apparatus in which the elastic layer 6 is provided on the surface of the base layer 4 is obtained.

  Various conditions for producing the base layer 4 and the elastic layer 6 according to the dispenser coating method as described above, specifically, the rotational speed of the base 10, the moving speed of the nozzle, and the discharge amount of each material are as follows. The average waviness height on the surface, and the waviness pitch and waviness average height on the surface of the elastic layer 6 are appropriately determined so as to be within the scope of the present invention.

  Specifically, first, when the rotation speed of the substrate 10 is increased (decreased), the average undulation height of the base layer 4 is decreased (increased), and therefore the rotation speed of the substrate 10 is generally within a range of 50 to 500 rpm. Is appropriately determined.

  Further, since the waviness pitch of the base layer 4 and the elastic layer 6 becomes larger (smaller) when the nozzle moving speed becomes larger (smaller), the moving speed of each nozzle (first nozzle, second nozzle) is usually 0. It is set within the range of 1 to 10.0 mm / sec.

  Furthermore, if the discharge amount of the base layer (elastic layer) material is too large, the average swell average height of the obtained base layer 4 (elastic layer 6) may be too large. On the other hand, if the discharge amount is too small, The average swell height of the obtained base layer 4 (elastic layer 6) may be too small. For this reason, the discharge amount of the base layer (elastic layer) material is generally set within a range of 0.1 to 5.0 g / sec.

  In the method described above, a solid columnar substrate can be used instead of the cylindrical substrate 10, but the cylindrical substrate is advantageous from the viewpoint of reducing the load on the rotating part. Used. Specifically, a rotating drum made of metal such as iron, aluminum, and stainless steel can be suitably used.

  In addition, as a nozzle for discharging a liquid material (base layer material, elastic layer material), a needle nozzle or the like is used, and the discharge portion has a round shape, a flat shape, a rectangular shape, or the like. I can do it.

  By the way, in the present invention, it is possible to further provide a surface layer as a protective layer on the surface of the two-layer belt composed of the base layer 4 and the elastic layer 6 obtained as described above (the surface of the elastic layer 6). It is. The surface layer as such a protective layer can be prepared according to various conventionally known methods using a material mainly composed of a synthetic resin material such as an acrylic fluororesin, and a liquid material is prepared and the liquid layer is prepared. Of course, it is also possible to produce the material according to the above-described dispenser coating method.

  In the endless belt 2 for an electrophotographic apparatus thus obtained, the elastic layer 6 is provided on the surface of the base layer 4 having an average waviness of 0.5 to 4.0 μm. In the belt surface, that is, the surface of the elastic layer 6, the undulation pitch is set to 0.5 to 3.0 mm, and the average undulation height is set to 0.7 μm or less. With such a configuration, in the endless belt 2 for electrophotographic equipment of the present invention, delamination between the base layer 4 and the elastic layer 6 is effectively suppressed, and excellent durability is exhibited. Since the surface is effectively smooth, even if the toner remains on the belt surface after the secondary transfer to the printing material, the residual toner can be removed by a predetermined cleaning mechanism. It is easy and exhibits excellent cleaning properties.

  Some examples of the present invention will be shown below to clarify the present invention more specifically. However, the present invention is not limited by the description of such examples. Needless to say. In addition to the following examples, the present invention includes various changes and modifications based on the knowledge of those skilled in the art without departing from the spirit of the present invention, in addition to the specific description described above. It should be understood that improvements can be made.

-Preparation of base layer material-
First, Rika Coat EN-20 (product name) manufactured by Shin Nippon Rika Co., Ltd. is used as the polyimide resin (PI), and Viromax HR-16NN (product name) manufactured by Toyobo Co., Ltd. is used as the polyamideimide resin (PAI). By preparing and mixing any one of these resins: 100 parts by weight and carbon black: 10 parts by weight in a predetermined amount of N-methyl-2-pyrrolidone (NMP), and mixing, A liquid base layer material was prepared. The viscosity of each base layer material was adjusted by changing the amount of NMP used. Tables 1 and 2 below show the synthetic resin materials and viscosities that are the main components of the base layer materials used in the examples and comparative examples.

-Preparation of elastic layer material-
100 parts by weight of acrylonitrile-butadiene rubber (NBR), butadiene rubber (BR), styrene butadiene rubber (SBR), butyl rubber (IIR) or chloroprene rubber (CR), resin crosslinking agent: 70 parts by weight, and ionic conductive agent: A mixture of 1 part by weight and 50 parts by weight of a flame retardant in a predetermined amount of cyclohexanone was mixed to prepare a plurality of liquid elastic layer materials. The viscosity of each elastic layer material was adjusted by changing the amount of cyclohexanone used. Each component used in the preparation of the elastic layer material is as follows. Tables 1 and 2 below show the rubber materials and viscosities as the main components of the elastic layer materials used in the examples and comparative examples.
・ Acrylonitrile-butadiene rubber (NBR)
: Nipol DN101 (trade name), manufactured by ZEON CORPORATION ・ Butadiene rubber (BR): Nipol BR1220 (trade name), manufactured by ZEON CORPORATION ・ Styrene butadiene rubber (SBR): Toughden 1000 (trade name), Asahi Kasei Corporation・ Butyl rubber (IIR): JSR BUTYL 365 (trade name), manufactured by JSR Corporation ・ Chloroprene rubber (CR)
: Denkachloroprene DCR-75 (trade name), manufactured by Denki Kagaku Kogyo Co., Ltd. ・ Ionic conductive agent: quaternary ammonium salt (tetrabutyl ammonium hydrogen sulfate, TBAHS), manufactured by Wako Pure Chemical Industries, Ltd. ・ Flame retardant: Halogen-containing Phosphate ester (trade name: CR-570), manufactured by Daihachi Chemical Industry Co., Ltd.

-Preparation of surface layer material-
Toluene as a solvent, 70 parts by weight of an acrylic resin (manufactured by Negami Kogyo Co., Ltd., trade name: Precoat 200), 30 parts by weight of a fluorine-modified acrylate resin (manufactured by DIC Corporation, trade name: Defensor TR230K), and crosslinking 2 parts by weight of an agent (manufactured by Asahi Kasei Co., Ltd., trade name: Duranate TPA-B80E) and 20 parts by weight of carbon black (trade name: carbon black MA-100, made by Mitsubishi Chemical Corporation), A liquid surface layer material (solid content: 15%) was prepared.

-Production of belt-
As a substrate, an aluminum cylindrical mold was prepared, while a dispenser (liquid metering device) having two nozzles and a material tank was prepared. The nozzle of such a dispenser is a needle nozzle having an inner diameter φ of 1 mm. Next, the previously prepared liquid base layer material and elastic layer material were accommodated in separate material tanks, and the mold and nozzle were set with the clearance between the outer peripheral surface of the mold and the nozzle set to 1 mm. While the mold is in a vertical state, the nozzle for discharging the base layer material is moved downward in the axial direction at a predetermined moving speed while rotating about the axis at a rotational speed of 200 rpm, and the base layer material is removed from the material tank. The base layer material was discharged from the nozzle, and the outer peripheral surface of the mold was spirally coated to form a whole coating film composed of a continuous spiral coating film (see FIG. 3). In the following examples and comparative examples, the moving speed of the nozzle and the discharge amount of the material were appropriately changed. A heat treatment (normal temperature → 250 ° C .: 2 hours, 250 ° C .: 1 hour) was performed on the formed whole coating film to form a base layer on the outer peripheral surface of the mold.

  Next, while rotating the mold on which the base layer is formed around the axis at a rotational speed of 200 rpm, the nozzle for discharging the elastic layer material is moved along the axial direction at a predetermined moving speed, and the material The elastic layer material is sent from the tank to the nozzle, and the elastic layer material is discharged from the nozzle to coat the surface of the base layer on the outer peripheral surface of the mold in a spiral manner. A coating film was formed. In the following examples and comparative examples, the moving speed of the nozzle and the discharge amount of the material were appropriately changed. The total thickness of the formed coating film was 170 μm. By applying heat treatment (normal temperature → 170 ° C .: 3 hours, 170 ° C .: 0.5 hour) to the formed coating film, an elastic layer is provided on the base layer surface on the outer peripheral surface of the mold. A belt was produced.

  Then, a surface layer material is applied to the surface of the obtained belt having a two-layer structure (base layer + elastic layer) according to the same method as that for the base layer, and then heat-treated at 150 ° C. for 0.5 hour. Thus, 23 types of endless belts for electrophotographic equipment having a three-layer structure comprising a base layer, an elastic layer and a surface layer were produced (Examples 1 to 18 and Comparative Examples 1 to 5). The thickness of the surface layer was 5 μm.

  For the 23 types of belts thus obtained, the average swell height on the surface of the base layer, the swell pitch and swell average height on the belt surface were measured or calculated, and the following evaluation was performed. Note that Surfcom 1400D (trade name) manufactured by Tokyo Seimitsu Co., Ltd. was used for measurement or calculation of the average swell height and swell pitch. The measurement results and the like for each belt are shown in Tables 1 and 2 below.

-Evaluation of axial adhesion strength of belt-
A sample having a length in the axial direction: about 120 mm × a length in the width direction: 25 mm is cut out from the belt, and one end of the sample in the longitudinal direction (belt axial direction) is gripped by an autograph. The other end was gripped with a peeling method jig, a tensile test was performed at a tensile speed of 20 mm / min in this state, and the minimum value of the obtained results was defined as the belt adhesion. When the adhesive force was 1.0 (N / 25 mm) or more, it was evaluated as “good”, and when it was less than 1.0 (N / 25 mm), it was evaluated as “poor”.

-Evaluation of cleaning performance-
The obtained belt is incorporated into a commercially available laser printer (trade name: bizhub550, manufactured by Konica Minolta Co., Ltd.) as an intermediate transfer belt, and 500,000 images are printed in an environment of 23.5 ° C. × 53% RH (test pattern printing). A durability test was conducted. The image at the start of the endurance test was compared with the image at the end, and the image at the end was visually checked for the presence or absence of abnormal images such as stripes in the scanning direction and missing images. In the image at the end, when an abnormal image was not recognized, ○ was evaluated, and when an abnormal image was recognized, X was evaluated.

-Evaluation of durability-
After the durability test described above, the belt was removed from the laser printer, and the presence or absence of physical cracks, breaks, breakage, etc. in the belt was visually confirmed. The case where no crack or the like was observed on the belt was evaluated as “Good”, and the case where it was recognized as “Poor”.

  As is clear from Table 1 and Table 2, the endless belts for electrophotographic equipment (Examples 1 to 18) according to the present invention are both excellent in durability and excellent in cleaning properties. Therefore, it has been confirmed that the occurrence of contamination on the belt surface and image unevenness can be effectively suppressed.

2 Endless Belt for Electrophotographic Equipment 4 Base Layer 6 Elastic Layer 10 Base 12 Base Layer Material 14 First Material Tank 16 First Nozzle

Claims (7)

  An endless belt for electrophotographic equipment in which an elastic layer is provided on the surface of a base layer having an average waviness height of 0.5 to 4.0 μm, and the waviness pitch of the surface is 0.5 to 3.0 mm An endless belt for electrophotographic equipment, characterized in that the mean undulation height is 0.7 μm or less.   The base layer is formed according to a dispenser coating method using a liquid base layer material mainly composed of a synthetic resin material, and the elastic layer is composed of a liquid elastic layer material mainly composed of a rubber material. The endless belt for an electrophotographic apparatus according to claim 1, wherein the endless belt is formed according to a dispenser coating method.   The endless belt for an electrophotographic apparatus according to claim 2, wherein the base layer material is mainly composed of a polyimide resin or a polyamideimide resin.   The electrophotographic apparatus according to claim 2 or 3, wherein the elastic layer material is mainly composed of at least one of acrylonitrile-butadiene rubber, butadiene rubber, styrene-butadiene rubber, butyl rubber, or chloroprene rubber. Endless belt for equipment.   The endless belt for an electrophotographic apparatus according to any one of claims 2 to 4, wherein the base layer material has a viscosity of 1000 to 50000 mPa · s.   The endless belt for an electrophotographic apparatus according to any one of claims 2 to 5, wherein the elastic layer material has a viscosity of 1000 to 70000 mPa · s. The endless belt for an electrophotographic apparatus according to claim 1, wherein the base layer has a thickness of 50 to 200 μm.

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