JP2012078522A - Seamless belt for image forming apparatus and manufacturing method thereof, and image forming apparatus using seamless belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seamless belt that reduces smoothness of an interface between the seamless belt and a surface protective layer and thereby reduces glossiness of the belt surface so that the glossiness change associated with the use of the belt is suppressed.SOLUTION: A seamless belt includes a seamless surface protective layer having a peel strength of 2 to 400 g/25 mm that is peelably provided on the surface of a belt base material that constitutes the seamless belt, and irregularities that are formed on the surface of the belt base material.

Description

  The present invention relates to a seamless belt for a forming apparatus to which a surface protective layer mixed with a filler is applied, a method for producing the same, and an image forming apparatus using the seamless belt.

  In recent years, an image forming apparatus using an intermediate transfer member as an image carrier for transferring a toner image onto a transfer paper has been widely adopted because of the need for high-quality color image formation. After the toner images of the respective colors formed on the surface of the photosensitive drum, which is a primary transfer body, which are arranged in a plurality along the moving direction of the intermediate transfer body, are transferred and superimposed on the intermediate transfer body, which is a secondary transfer body. Further, it is secondarily transferred from the intermediate transfer member to the transfer paper.

  A seamless belt is employed as such an intermediate transfer member or as a transfer conveyance belt. However, seamless belts are required to have uniform electrical resistance in the semiconductive region. In order to obtain clear images in various usage environments, the electrical resistance changes even when the usage temperature and humidity change. In addition to electrical characteristics such as small electrical resistance change even when voltage is repeatedly applied, mechanical characteristics such as low elongation even when stress is applied, and belt surface characteristics are required. For the intermediate transfer belt in which the toner is in direct contact, the surface condition of the belt (surface roughness, surface contact angle, surface dirt, scratches, creases) is important. The surface roughness and surface contact angle are generally determined by the composition of the belt material and the processing method. However, dirt, scratches, and creases on the belt surface may occur during handling after processing into a seamless belt, resulting in product yield. There was a problem of causing a drop in

  In order to cope with such a problem, in the invention described in Patent Document 1, a seamless surface protective layer is weakly adhered to the surface of the seamless belt, that is, it can be easily removed at the time of use, 2 g / 25 mm to 400 g / It has been proposed to provide a seamless surface protective layer with a peel strength of 25 mm width.

  In the invention of Patent Document 1, since the smoothness of the seamless belt, the surface protective layer, and the interface is high, the glossiness of the belt surface is increased. Therefore, even if the surface protective layer is peeled off and the coating layer is applied, the glossiness is increased due to the surface of the base belt. The amount of toner on the belt is controlled by reading the glossiness and glossiness unevenness of the belt surface with a sensor. Therefore, if the glossiness is high and the glossiness unevenness is large, it becomes difficult to control due to changes in durability. . In order to reduce the glossiness of the belt surface, it was necessary to prepare application conditions for applying the surface coat layer to the belt surface. However, when prepared under coating conditions, there is a problem that the glossiness of the coating layer tends to be uneven, glossiness unevenness increases, and the desired glossiness cannot be obtained.

JP 2005-234127 A

  Therefore, in order to solve the above problems, the present invention can reduce the smoothness of the interface between the seamless belt and the surface protective layer, thereby reducing the glossiness of the belt surface and suppressing the change in glossiness associated with use. An object is to provide a seamless belt that can be used.

In order to achieve this object, the present invention has the following configuration.
The invention according to claim 1 is a seamless belt for an image forming apparatus, and a seamless surface protective layer can be peeled off with a peel strength of 2 to 400 g / 25 mm width on the surface of a belt base material constituting the seamless belt. Provided in
The present invention relates to a seamless belt for an image forming apparatus, wherein irregularities are formed on the surface of the belt base material.

The invention according to claim 2 is for an image forming apparatus, wherein the surface protective layer includes a filler, and the filler is interposed between a surface of the belt base material and the surface protective layer. Concerning seamless belts.

  The invention according to claim 3 relates to a seamless belt for an image forming apparatus according to claim 1 or 2, wherein a coating layer is applied to the surface of the belt base material in a state where the surface protective layer is peeled off.

The invention according to claim 4 is a method of manufacturing a seamless belt for an image forming apparatus,
(A) adding the components of the belt base material constituting the seamless belt to a kneader and kneading to obtain pellets;
(B) a step of obtaining a tubular body by extruding the pellet obtained in the step (a) with an extruder;
(C) after covering the tubular body on a mold, covering the tubular body with a tubular body formed from components constituting a surface protective layer, heating and fusing,
The present invention relates to a process for producing a seamless belt, wherein a filler is contained in a component constituting the surface protective layer.

  The invention according to claim 5 relates to an image forming apparatus using the seamless belt according to claim 3 as an intermediate transfer belt.

  According to the first aspect of the present invention, there is provided a seamless belt for an image forming apparatus, wherein a seamless surface protective layer is formed on the surface of a belt base material constituting the seamless belt with a peel strength of 2 to 400 g / 25 mm width. Since it is provided so that it can be peeled off and unevenness is formed on the surface of the belt base material, the smoothness of the interface between the belt base material and the surface protective layer can be lowered, and as a result, a seamless belt The glossiness of the surface can be reduced.

  According to the invention according to claim 2, the surface protective layer includes a filler, and the filler is interposed between the surface of the belt base material and the surface protective layer. Unevenness can be formed on the surface of the belt base material by the filler. As a result, the smoothness of the interface between the belt base material and the surface protective layer can be lowered, and the glossiness of the seamless belt surface can be reduced.

  According to the invention according to claim 3, since the surface protective layer is peeled off, a coating layer is applied to the surface of the belt base material. Therefore, the smoothness of the surface of the seamless belt can be lowered, and the glossiness of the surface of the seamless belt can be reduced.

  According to the invention of claim 4, there is provided a process for producing a seamless belt for an image forming apparatus, wherein (a) the components of the belt base material constituting the seamless belt are put into a kneader, kneaded, and lett (B) a step of obtaining a tubular body by an extruder from the pellet obtained in the step (a), and (c) a surface protective layer is applied to the tubular body after the tubular body is covered with a mold. Covering the tubular body formed from the constituent components, heating and fusing, and the component constituting the surface protective layer is characterized by comprising a filler. By heat-sealing the surface protective layer on the surface, irregularities are formed on the surface of the belt base material, and the smoothness of the interface between the belt base material and the surface protective layer can be lowered, and consequently the gloss of the seamless belt surface. Degree can be reduced It is possible to provide a Muresuberuto.

  According to the invention of claim 5, since the seamless belt according to claim 3 is used for the intermediate transfer belt constituting the image forming apparatus, an image forming apparatus for realizing further improved high-quality color image formation is provided. Can be provided.

It is explanatory drawing which shows the process of the manufacturing method of the seamless belt for image forming apparatuses which concerns on one embodiment of this invention. It is explanatory drawing which shows the state from which the protective surface was removed from the belt base material with a protective surface obtained by the manufacturing method of the seamless belt for image forming apparatuses which concerns on one embodiment of this invention. FIG. 4 is a cross-sectional explanatory view of a seamless belt obtained by a method for producing a seamless belt for an image forming apparatus according to an embodiment of the present invention. 1 is a schematic cross-sectional view of an image forming apparatus according to an embodiment of the present invention. FIG. 3 is an enlarged vertical cross-sectional view around the intermediate transfer device according to the embodiment of the present invention. FIG. 3 is an enlarged vertical cross-sectional view around the image forming unit according to the embodiment of the present invention.

A seamless belt for an image forming apparatus according to the present invention, a method for producing the seamless belt, and an image forming apparatus using the seamless belt will be described in detail below with reference to the accompanying drawings.
FIG. 1a is an explanatory view showing a process of a seamless belt manufacturing method for an image forming apparatus according to an embodiment of the present invention. FIG. 1B is an explanatory view showing a state in which the protective surface is removed from the belt base material with the protective surface obtained by the method of manufacturing a seamless belt for the image forming apparatus according to the embodiment of the present invention. FIG. 1C is a cross-sectional explanatory view of a seamless belt obtained by a method for producing a seamless belt for an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a schematic sectional view of an image forming apparatus according to an embodiment of the present invention. FIG. 3 is an enlarged vertical sectional view of the periphery of the intermediate transfer device according to the embodiment of the present invention. FIG. 4 is an enlarged vertical sectional view of the periphery of the image forming unit according to the embodiment of the present invention.

Embodiment 1
Referring to FIG. 1a, the method for producing a seamless belt for an image forming apparatus according to the present embodiment includes the following steps (a), (b) and (c). In addition, the arrow in FIG. 1a has shown performing heat processing.

In the step (a), a material comprising the components constituting the belt base materials (B1) and (B2) is put into a biaxial kneader (not shown) and kneaded to obtain belt base material pellets.
The illustrated belt base material (B1), (B2) is composed of an upper layer part (B1) and a lower layer part (B2), but is not limited to such a structure. For example, it is composed of one upper layer part (31). (In this case, a uniaxial kneader is used), an intermediate layer may be provided between the upper layer part (B1) and the lower layer part (B2), and such a configuration is also included in the present invention. It is. Examples of materials used for the belt base materials (B1) and (B2) according to the present embodiment include fluorine resins such as polyethylene, polypropylene, polyvinyl fluoride, ethylene-tetrafluoroethylene copolymer, and polyvinylidene fluoride. , Vinyl chloride resin, ABS resin, polymethyl methacrylate, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, nylon, polyimide, hydrogenated styrene-butadiene copolymer, polyether ester, thermoplastic polyurethane, etc. Or 2 or more types are mentioned.

  In the step (b), the belt base material pellet obtained in the step (a) is taken out using an extruder (not shown) equipped with an annular die (not shown) and formed into a tubular body.

In the step (c), the tubular body obtained in the step (b) is covered with a mold, and a tubular body formed from components constituting the surface protective layer (PL) is further formed on the tubular body. Cover, heat and pressurize. In addition, the filler (F) is contained in the component which comprises a surface protective layer.

Examples of the material for the surface protective layer (PL) include polyolefins such as polyethylene, polypropylene, and modified polyethylene, fluorine resins such as polyvinyl fluoride, ethylene-tetrafluoroethylene copolymer, and polyvinylidene fluoride, vinyl chloride resins, and ABS resins. One or two or more of polymethyl methacrylate, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, nylon and the like can be employed.
A seamless belt having a surface roughness can be obtained. As the material of the filler (F), for example, polytetrafluoroethylene (PTFE), an organic filler having a melting point equal to or higher than the melting temperature, and an inorganic filler such as titanium oxide can be employed. The filler (F) The shape of is not limited to the illustrated spherical shape, and may be an amorphous one.

Since the surface protective layer (PL) is weakly bonded to the belt substrate (B1), the peel strength between the belt substrate (B1) and the surface protective layer (PL) is 2 to 400 g / 25 mm width. Is good. For that purpose, polyolefins such as polyethylene, polypropylene, and modified polyethylene, and fluorine resins such as polyethylene terephthalate, polyvinyl fluoride, ethylene-tetrafluoroethylene copolymer, and polyvinylidene fluoride are preferable.

The seamless belt according to the present embodiment is obtained by kneading the components of the belt base material (B1) with a twin-screw kneader to form pellets, and then using an extruder equipped with an annular die, the upper layer portion (B1), the lower layer The belt base materials (B1), (B2) are extruded by extruding a tubular body having a predetermined thickness for each of the portions (B2), and then cutting the tubular body into round pieces and superposing them on a cylindrical mold. ) And the surface protective layer (PL) are heat-sealed. By heat-sealing, uneven portions (B1a) and (B1b) are generated in the belt base material upper layer part (B1), and the belt base material (31 ) And (32) are obtained by thermally fusing the surface protective layer (PL). Thereafter, the surface protective layer (PL) is peeled off and removed, and as shown in FIG. 1b, the belt base material (B1) in which the concave and convex portions (B1a) and (B1b) are provided on the belt base material (B1). , (B2) is obtained.
Next, as shown in FIG. 1c, a coating layer made of, for example, a polytetrafluoroethylene (PTFE) -based synthetic resin material is formed on the surface of the belt base material (31) where the uneven portions (B1a) and (B1b) are present. By applying (CL), a seamless belt for an intermediate transfer belt can be obtained.
According to this embodiment, since the filler (F) is included in the component constituting the surface protective layer (PL), the surface protective layer (PL) is heat-sealed to the surface of the belt base material (B1). As a result, irregularities (B1a) and (B1b) are formed on the surface of the belt base material upper layer part (31), and the smoothness of the interface between the belt base material upper layer part (B1) and the surface protective layer (PL) is improved. Thus, the glossiness of the surface of the seamless belt can be reduced.

Embodiment 2
An outline of the structure of the image forming apparatus according to the present embodiment will be described with reference to FIGS. 2, 3, and 4.

  As shown in FIG. 2, a paper feed cassette (3) is disposed below the inside (2) of the main body (2) of the image forming apparatus (1). A first paper transport section (4) is provided on the left side of the paper feed cassette (3). The first paper transport unit (4) receives the paper (P) sent out from the paper feed cassette (3) and transports it vertically upward along the left side surface of the main body (2) to the secondary transfer unit (40). .

  Manual paper feed is provided above the paper feed cassette (3) on the right side, which is the side opposite to the left side of the main body (2) where the first paper transport unit (4) is formed. Part (5) is provided. In the manual paper feed section (5), paper that is not contained in the paper feed cassette (3), a thick paper, or an OHP sheet is loaded one by one.

  A second paper transport unit (6) is provided to the left of the manual paper feed unit (5). The second paper transport unit (6) is located immediately above the paper feed cassette (3) and extends substantially horizontally from the manual paper feed unit (5) to the first paper transport unit (4). It joins (4). The second paper transport unit (6) receives the paper fed from the manual paper feed unit (5), and transports it substantially horizontally to the first paper transport unit (4).

  On the other hand, the image forming apparatus (1) receives document image data from an external computer (not shown). This image data information is sent to a laser irradiation section (7) which is an exposure means disposed above the second paper transport section (6). The laser beam (L) controlled based on the image data is irradiated toward the image forming unit (20) by the laser irradiation unit (7).

As shown in FIGS. 2 and 3, a total of four image forming units (20) are disposed above the laser irradiation unit (7), and an intermediate transfer member is disposed endlessly above each of the image forming units (20). An intermediate transfer belt (8) used in the form of a belt is provided.
In the present embodiment, as the intermediate transfer belt (8), as shown in FIG. 1c detailed in the first embodiment, a belt base material (31) having uneven portions (B1a) and (B1b) is present. The greatest feature lies in that a seamless belt obtained by applying a coat layer (CL) to the surface is used.
The intermediate transfer belt (8) is supported by being wound around a plurality of rollers, and is rotated clockwise in FIG. 3 by a driving device (not shown).

  As shown in FIGS. 2 and 3, the four image forming units (20) are arranged in a line from the upstream side to the downstream side in the rotational direction along the rotational direction of the intermediate transfer belt (8). This is a so-called tandem system. The four image forming units (20) are, in order from the upstream side, a magenta image forming unit (20M), a cyan image forming unit (20C), a yellow image forming unit (20Y), and a black image forming unit. The image forming unit (20B). These image forming units (20) are replenished with a developer (toner) by a developer supply container and a conveying unit (not shown) corresponding to each color. In the following description, the identification symbols “M”, “C”, “Y”, and “B” are omitted unless particularly limited.

  In each image forming unit (20), an electrostatic latent image of a document image is formed by laser light (L) irradiated by a laser irradiation unit (7) as an exposure unit, and a toner image is developed from the electrostatic latent image. Is done. The toner image is primarily transferred onto the surface of the intermediate transfer belt (8) by a primary transfer section (30) provided above each image forming section (20). Then, as the intermediate transfer belt (8) rotates, the toner image of each image forming section (20) is transferred to the intermediate transfer belt (8) at a predetermined timing, so that the surface of the intermediate transfer belt (8) is magenta. A color toner image is formed by superimposing four color toner images of cyan, yellow, and black.

  A secondary transfer portion (40) including a secondary transfer roller (41) is disposed at a position where the intermediate transfer belt (8) is suspended on the sheet conveyance path. The color toner image once carried on the surface of the intermediate transfer belt (8) is transferred to the sheet fed synchronously by the first sheet transport unit (4), and the intermediate transfer belt (8) and the secondary transfer roller (41). Are transferred at a secondary transfer nip portion formed by pressure contact.

  After the secondary transfer, deposits such as toner remaining on the surface of the intermediate transfer belt (8) are intermediately provided on the upstream side in the rotation direction of the magenta image forming portion (20M) with respect to the intermediate transfer belt (8). It is cleaned and collected by a cleaning device (9) for the transfer belt (8).

  A fixing unit (10) is provided above the secondary transfer unit (40). The paper (P) carrying the unfixed toner image in the secondary transfer section (40) is sent to the fixing section (10), and the toner image is heated and pressed by the heat roller and the pressure roller to be fixed. Is done.

  A branch portion (11) is provided above the fixing portion (10). When screen printing is not performed, the paper discharged from the fixing unit (10) is discharged from the branching unit (11) to a paper discharge unit (12) provided at the upper part of the image forming apparatus (1).

  The discharge port portion from which the paper is discharged from the branching portion (11) toward the paper discharge portion (12) serves as a switchback portion (13). When performing double-sided printing, the transport direction of the paper discharged from the fixing unit (10) is switched in the switchback unit (13). Then, the sheet passes through the branch part (11), the left side of the fixing part (10), and the left side of the secondary transfer part (40), and is sent downward, and again passes through the first sheet transport part (4). Then, it is sent to the secondary transfer section (40).

  Next, a detailed configuration around the image forming unit (20) and the intermediate transfer belt (8) of the image forming apparatus (1) will be described with reference to FIG. 4 in addition to FIG. FIG. 4 is an enlarged vertical sectional view showing the periphery of the image forming unit. Since the four color image forming units (20) have the same structure, the identification symbols “M”, “C”, “Y”, and “B” are omitted as described above.

  As shown in FIG. 4, the image forming unit (20) includes a photosensitive drum (21) as an image carrier at the center thereof. In the vicinity of the photosensitive drum (21), a charging device (50), a developing device (60), a charge eliminating device (70), and a drum cleaning device (80) are arranged in this order along the rotation direction. Has been. The primary transfer section (30) is provided between the developing device (60) and the charge removal device (70) along the rotation direction of the photosensitive drum (21).

  The photosensitive drum (21) extends in the paper width direction perpendicular to the paper conveyance direction in the image forming apparatus (1), that is, the paper surface depth direction in FIG. The photosensitive drum (21) is an inorganic photosensitive drum in which an amorphous silicon photosensitive layer, which is an inorganic photoconductive material, is provided on the outside of a conductive roller-shaped substrate made of aluminum or the like by vacuum deposition or the like. The diameter is 30 mm. The photosensitive drum (21) is rotated by a driving device (not shown) so that the peripheral speed thereof is substantially the same as the paper conveyance speed (150 mm / s). Note that the four image forming apparatuses (20) shown in FIG. 2 are rotated by separate driving devices each having a DC motor and a gear.

  The charging device (50) includes a charging roller (52) in contact with the photosensitive drum (21) inside the housing (51). The charging roller (52) is pressed against the photosensitive drum (21) with a predetermined pressure, and rotates according to the rotation of the photosensitive drum (21). The charging roller (52) uniformly charges the surface of the photosensitive drum (21) with a predetermined polarity and potential. The charging potential at this time is normally plus 350V. In the housing (51), a cleaning brush (53) is provided at a position separating the charging roller (52) from the photosensitive drum (21), and the charging roller (52) is provided by the cleaning brush (53). The surface is cleaned.

  The developing device (60) includes a developing roller (62) and a supply screw (63) inside the housing (61). The developing roller (62) is provided in the vicinity of the photosensitive drum (21), with a developing method being contact or non-contact. A bias having the same polarity as the charging polarity of the photosensitive drum (21) is applied to the developing roller (62). Next, the developing roller (62) charges the toner as a developer and moves it to the electrostatic latent image on the surface of the photosensitive drum (21) to develop the electrostatic latent image.

  The developing device (60) uses, as a developer, a two-component toner obtained by mixing a polar carrier and a non-polar toner, but is a type using a magnetic or non-magnetic one-component toner. It doesn't matter. Further, in order to clean the surface of the photosensitive drum (21) by polishing, a small amount of powder such as titanium oxide and silica is mixed in the toner as an external additive. The toner is accommodated in a developer supply container (not shown), conveyed to a developing device (60) by a conveying means (not shown), and replenished inside the housing (61) by a supply screw (63).

  The primary transfer portion (30) is provided with a primary transfer roller (31) that comes into contact with the photosensitive drum (21) via the intermediate transfer belt (8). The primary transfer roller (31) is, for example, a roller having a diameter of 20 mm and an EPDM (ethylene propylene diene rubber) foam having a thickness of 6 mm provided on a metal shaft having a diameter of 8 mm, and an electric resistance value of 6.5 log [Ω]. ]. The primary transfer roller (31) does not have a driving device, and rotates according to the rotation of the intermediate transfer belt (8) by contacting the intermediate transfer belt (8).

  Among the rollers supporting the intermediate transfer belt (8), as shown in FIG. 2, in the vicinity of the secondary transfer portion (40), it corresponds to the secondary transfer roller (41) with the intermediate transfer belt (8) interposed therebetween. The roller provided at the location is the drive roller (8a).

  As shown in FIG. 3, the static eliminator (70) of the image forming unit (20) is disposed on the downstream side of the primary transfer unit (30) along the rotation direction of the photosensitive drum (21). The static elimination apparatus (70) is comprised by LED (light emitting diode) (71) and the reflecting plate (72). The LED (71) is attached to the upper surface of the housing (81) of the cleaning device (80). Instead of the LED (71), an EL (electroluminescence) light source, a fluorescent lamp, or the like can be used. The reflector (72) is provided above the LED (71) so as to cover the LED (71). The static eliminator (70) irradiates the photosensitive drum (21) with the static elimination light from the LED (71) to remove the charged charges on the surface, and prepares for the charging process in the next image forming operation. Arrange.

  The cleaning device (80) is arranged further downstream of the primary transfer unit (30) and the charge removal device (70) along the rotation direction of the photosensitive drum (21). The cleaning device (80) includes a cleaning roller (82), a cleaning blade (83), a toner receiving member (84), a transport paddle (85), and a toner discharge screw (86) inside the housing (81). ing. The cleaning roller (82) and the cleaning blade (83) are brought into pressure contact with the photosensitive drum (21), and remove adhering matters such as toner remaining on the surface of the photosensitive drum (21) for cleaning. The toner removed from the surface of the photosensitive drum (21) is temporarily stored inside the toner receiving member (84), and the overflowed toner is cleaned by the toner discharge screw (86) via the transport paddle (85). The toner is discharged to a waste toner collecting container (not shown) outside the apparatus (80).

Hereinafter, the effect of the present invention will be clarified by showing examples of the seamless belt according to the present invention.
However, the present invention is not limited to the following examples.

Using a twin-screw kneader, 100 parts by weight of thermoplastic polyurethane (TPU) was melt-kneaded with 4.0 parts by weight of polyethyleneoxy and 0.4 parts by weight of lithium perchlorate as pellets A.
Low density polyethylene (LDPE) tubular body A: 50 parts by weight of PTFE filler (5 μm) with respect to 100 parts by weight of low density polyethylene,
Low density polyethylene (LDPE) tubular body B: 20 parts by weight of PTFE filler (5 μm) with respect to 100 parts by weight of low density polyethylene,
Low density polyethylene (LDPE) tubular body B: Only low density polyethylene was prepared.
Example 1
The pellet A was formed into a single-layer tubular body having a thickness of 500 μm and a folding diameter of 125 mm using a 25 mm extruder equipped with an annular die having a lip diameter of 50 mm. The obtained tubular body is covered with a mold having an outer diameter of 80 mm, and further, a low-density polyethylene (LDPE) tubular body A having a folding diameter of 125 mm and a thickness of 50 μm is covered thereon, heat-sealed, and an outer diameter of 80 mm. A seamless belt with a surface protective layer was obtained. Table 1 shows the peel strength, surface roughness (Rz), and glossiness of the surface protective layer of the obtained seamless belt with the surface protective layer.
Example 2
The pellet A was formed into a single-layer tubular body having a thickness of 500 μm and a folding diameter of 125 mm using a 25 mm extruder equipped with an annular die having a lip diameter of 50 mm. The obtained tubular body is covered with a mold having an outer diameter of 80 mm, and further, a low-density polyethylene (LDPE) tubular body B having a folding diameter of 125 mm and a thickness of 50 μm is placed thereon, heat-sealed, and an outer diameter of 80 mm. A seamless belt with a surface protective layer was obtained. Table 1 shows the peel strength, surface roughness (Rz), and glossiness of the surface protective layer of the obtained seamless belt with the surface protective layer.
Comparative Example 1
Using a 25 mm extruder equipped with an annular die having a lip diameter of 50 mm, the pellet A
Covered with a 0 mm mold, and further covered with a low-density polyethylene (LDPE) tubular body C with a folding diameter of 125 mm and a thickness of 50 μm, and heat-sealed to obtain a seamless belt with a surface protective layer with an outer diameter of 80 mm. It was. Table 1 shows the peel strength, surface roughness (Rz), and glossiness of the surface protective layer of the obtained seamless belt with the surface protective layer.

  From Table 1, the peel strengths of Examples 1 and 2 were almost the same as those of Comparative Example 1, the surface roughness was 4 to 10 times that of the conventional one, and the glossiness was 18 to 36% of the conventional one. From this, it was possible to reduce the smoothness of the interface between the belt base material and the surface protective layer according to the present invention and to reduce the glossiness of the seamless belt surface.

  The seamless belt and the image forming apparatus using the seamless belt according to the present invention can be suitably used for various copying machines, printers, and FAX machines.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus 8 ... Intermediate transfer belt 9 ... Cleaning device 14 ... Density detection sensor 20 ... Image forming part 21 ... Photosensitive drum 30 ... Primary transfer part 31 ... Primary transfer roller 40 ·· Secondary transfer section 41 · · Secondary transfer roller 60 · · Development device 70 · · Static elimination device 80 · · Cleaning device (for drum)
B1 ・ ・ Belt base material (upper layer)
B2 ... Belt substrate (lower layer)
F ... Filler PL ... Surface protective layer CL ... Coat layer

Claims (5)

A seamless belt for an image forming apparatus, wherein a seamless surface protective layer is provided on a surface of a belt base material constituting the seamless belt so as to be peelable with a peel strength of 2 to 400 g / 25 mm width,
A seamless belt for an image forming apparatus, wherein unevenness is formed on a surface of the belt base material. The seamless belt for an image forming apparatus according to claim 1, wherein the surface protective layer includes a filler, and the filler is interposed between a surface of the belt base material and the surface protective layer.   The seamless belt for an image forming apparatus according to claim 1 or 2, wherein a coating layer is applied to the surface of the belt base material in a state where the surface protective layer is peeled off. A process for producing a seamless belt for an image forming apparatus,
(A) adding the components of the belt base material constituting the seamless belt to a kneader and kneading to obtain pellets;
(B) a step of obtaining a tubular body by extruding the pellet obtained in the step (a) with an extruder;
(C) after covering the tubular body on a mold, covering the tubular body with a tubular body formed from components constituting a surface protective layer, heating and fusing,
A process for producing a seamless belt, wherein a filler is contained in a component constituting the surface protective layer.   An image forming apparatus using the seamless belt according to claim 3 as an intermediate transfer belt.