JP2008116486A - Belt tubular body and image forming device provided with it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a belt tubular body for preventing one-sided traveling or meandering over a long period of time without causing life deterioration of a belt, and to provide a compact image forming device having high reliability by using the belt tubular body. <P>SOLUTION: The belt tubular body has an endless belt body, and a meandering prevention guide arranged to separate both the ends of a longitudinal direction along at least a one-sided edge part of the belt body. In the belt tubular body. One end of the longitudinal direction of the meandering prevention guide protrudes in a vertical direction in an axial direction and in a direction parallel to the longitudinal direction, both the ends of a width direction have a protrusion tapered toward a protrusion edge, and the other end has a recess corresponding to the protrusion. The image forming device provided with the belt tubular body is provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a belt tubular body and an image forming apparatus using the belt tubular body.

  As an image forming apparatus using an electrophotographic system, for example, there is an intermediate transfer type color image forming apparatus using an intermediate transfer belt. This is because an intermediate transfer belt that rotates in contact with a transfer portion of an image carrier (for example, a photosensitive drum) on which a toner image is formed by an electrophotographic process is stretched between a plurality of belt support rolls. The plurality of toner images formed on the image carrier are primarily transferred so as to be superimposed on the same position of the intermediate transfer belt, and then the toner image transferred onto the intermediate transfer belt is transferred to a sheet of paper. Are collectively transferred. The multiple toner images transferred onto the paper are then fixed by a fixing device to form a color image.

  In addition, as an image forming apparatus provided with a belt tubular body, there is also a so-called tandem type color image forming apparatus that uses a sheet conveying belt that conveys a sheet so as to pass through transfer portions of a plurality of image forming units. This is because a plurality of image forming units are arranged side by side in order to individually form toner images of each color component, and the sheet conveying belt is placed between a plurality of belt support rolls so as to rotate in contact with the transfer portion of each image forming unit. Each toner image formed in each image forming unit is the same by transporting the paper adsorbed on the paper transport belt so as to pass through the transfer section of each image forming unit. It is transferred so as to be sequentially superimposed on the paper, and finally fixed to form a color image.

  By the way, in such a color image forming apparatus using a belt tubular body such as an intermediate transfer belt or a paper transport belt, the parallelism of the rotation axes of the plurality of belt support rolls that support the belt tubular body and the outer diameter of the roll. The belt tubular body does not travel straight but travels in the axial direction of the belt support roll due to variations in tension and uneven tension due to changes in the circumference of the belt tubular body itself. In other words, so-called offset running or meandering may occur. For this reason, the position of each toner image that is sequentially transferred to the belt tubular body directly or onto the paper conveyed by the belt tubular body may be displaced. In this case, the toner image is finally formed on the paper. There is a problem that an image defect in which a color shift or a hue change occurs in a color image.

As a means for solving this problem, a belt having a meandering prevention guide is known. In this belt with meandering prevention guides, for example, meandering prevention guides made of elastic strips are bonded in the circumferential direction to both ends of the opening on the inner peripheral surface of the seamless belt, and both end faces of each meandering prevention guide abut each other. It is composed by bonding.
When such a meandering prevention guide is repeatedly bent at the roll portion, stress concentrates on both end faces of the meandering prevention guide, that is, the joint, and the meandering prevention guide may peel off. Along with the downsizing of the image forming apparatus, there is a tendency to use a roll having a small diameter, and further, stress tends to be concentrated at the joints of both end faces of the meandering prevention guide.
As means for solving such a problem, a method of providing a reinforcing material in the meandering prevention guide (see, for example, Patent Document 1), and a method of providing an adhesive in the joint of the meandering prevention guide (see, for example, Patent Documents 1 and 2). A method using a seamless meandering prevention guide is used.
Furthermore, by using the meandering prevention guides in which the opposite end faces are formed obliquely at a predetermined angle with respect to the circumferential direction, the meandering guide guide can be broken from the seam without causing an increase in the number of manufacturing steps and the number of parts. There is also a method of suppressing by a simple method (for example, see Patent Document 3).
Japanese Patent Laid-Open No. 2002-167021 Japanese Patent No. 3544192 JP 2002-72768 A

This invention is made | formed in view of the said situation, and makes the following content a subject.
That is, it is an object of the present invention to provide a belt tubular body capable of preventing a deviated running and meandering over a long period of time without causing a decrease in belt life.
It is another object of the present invention to provide an image forming apparatus that uses the belt tubular body and has high reliability and can be downsized.

The above problem is solved by the following means.
That is, the present invention
<1> An endless belt main body, and a meandering prevention guide disposed at both ends in the longitudinal direction apart along at least one edge of the belt main body,
One end in the longitudinal direction of the meandering prevention guide protrudes in a direction perpendicular to the width direction and parallel to the longitudinal direction, and both ends in the width direction are tapered toward the tip of the protrusion. A belt tubular body characterized in that it has a recess and the other end has a recess corresponding to the protrusion.

<2> Image carrier, charging unit for charging the surface of the image carrier, latent image forming unit for forming a latent image on the surface of the image carrier, and developing the latent image with toner to form a toner image Developing means for forming the toner image, transfer means for transferring the toner image to a recording medium, and fixing means for fixing the toner image to the recording medium, wherein at least one of the means is <1>. An image forming apparatus comprising: the belt tubular body described above; and a plurality of support rolls that rotatably support the belt tubular body.

<3> The image forming apparatus according to <2>, wherein at least one of the plurality of support rolls has a groove for the meandering prevention guide.

<4> The image forming apparatus according to <2> or <3>, wherein the belt tubular body is provided in contact with a plurality of units arranged in a substantially vertical direction.

ADVANTAGE OF THE INVENTION According to this invention, the belt tubular body which can prevent shifting and meandering over a long period of time can be provided, without causing the lifetime reduction of a belt.
Further, it is possible to provide an image forming apparatus that uses the belt tubular body and has high reliability and can be miniaturized.

<Belt tubular body>
The belt tubular body of the present invention has an endless belt main body, and a meandering prevention guide disposed at both ends in the longitudinal direction apart along at least one edge of the belt main body. And one end in the longitudinal direction of the meandering prevention guide projects in a direction perpendicular to the width direction and parallel to the longitudinal direction, and both ends in the width direction are tapered toward the tip of the projection. And the other end has a concave portion corresponding to the convex portion.

Hereinafter, the belt tubular body of the present invention will be described in detail with reference to the drawings. Here, FIG. 1 is a schematic perspective view showing the configuration of the belt tubular body of the present invention. FIG. 2 is an enlarged cross-sectional view of a main part for explaining the arrangement state of the meandering prevention guide with respect to the belt body in the belt tubular body of FIG.
As shown in FIG. 1, a belt tubular body 1 of the present invention is a belt tubular body in which a belt-like meandering prevention guide 3 is disposed along at least one side edge in the width direction of an endless belt body 2. It is. Further, as shown in FIG. 1, the belt tubular body 1 of the present invention preferably has a meandering prevention guide 3 provided on the inner peripheral surface of the belt body 2.
In particular, as shown in FIG. 2, in the belt tubular body 1 of the present invention, it is preferable that the meandering prevention guide 3 is bonded and fixed to the belt body 2 through the adhesive layer 4.
Hereinafter, each member which comprises the belt tubular body 1 of this invention is demonstrated.

-Belt body-
The belt body 2 constituting the belt tubular body 1 of the present invention is appropriately set in material, shape, size, etc. according to the use, function, etc. of the belt tubular body.
The belt body 2 may or may not have a joint. The thickness of the belt body 2 is usually preferably about 0.02 to 0.2 mm.

Examples of the material constituting the belt body 2 include a polyimide resin, a polyamideimide resin, a polyester resin, a polyurethane resin, a polyamide resin, and a fluorine resin.
As an example of the belt main body 2, when the belt tubular body 1 is applied to an intermediate transfer belt or a transfer conveyance belt in an image forming apparatus using an electrophotographic system, it is semiconductive made of a resin in which a conductive agent is dispersed. Belt. In this case, as a material for the semiconductive belt, for example, Toyobo Viromax HR16NN (solid content: 18% by mass) can be suitably used as a polyamideimide resin.

In addition, as described above, when a semiconductive belt is used as the belt body 2, carbon black and graphite are used to control the surface resistivity in the range of 1 × 10 ⁹ Ω / □ to 1 × 10 ¹⁴ Ω / □. Metals or alloys such as aluminum and copper alloys, metal oxides such as tin oxide, zinc oxide, kalim titanate, tin oxide-indium oxide or tin oxide-antimony oxide composite oxide, or conductive polymers such as polyaniline The conductive filler (conductive agent) is used. These may be used alone or in combination of two or more. Among these, carbon black is preferable as the conductive filler in terms of cost. Moreover, processing aids, such as a dispersing agent and a lubricant, can be added as needed.
Here, the surface resistivity was measured in an environment of 22 ° C. and 55% RH using a Hiresta UPMCP-450 type UR probe manufactured by Dia Instruments Co., Ltd., and measured according to JIS K 6911. 24 points (3 places in the width direction × 8 places in the circumferential direction) of the belt were measured, and the average value was taken as the surface resistivity of the belt.

-Meandering prevention guide-
The meandering prevention guide 3 constituting the belt tubular body 1 of the present invention has a belt-like shape, and is disposed with the end portions in the longitudinal direction spaced apart along at least one side edge of the endless belt body 2. Is. One end of the meandering prevention guide 3 in the longitudinal direction protrudes in a direction perpendicular to the width direction and parallel to the longitudinal direction, and both ends in the width direction are tapered toward the tip of the projection. And the other end needs to have a concave portion corresponding to the convex portion.

Here, the width direction of the meandering prevention guide is a direction parallel to the axial direction of the belt main body when disposed on the belt main body as shown in FIG. 1, and is indicated by an arrow X in FIG. Direction. The meander-preventing guide according to the present invention has, at one end in the longitudinal direction, a convex portion that projects in a direction perpendicular to the width direction and parallel to the longitudinal direction (that is, the longitudinal direction). This convex part is characterized by having a tapered shape from both ends in the width direction toward the protruding tip, which means that a tapered shape is formed from both ends of the width of the meandering prevention guide. That is, in the belt-shaped meandering prevention guide, a taper shape formed from one end (only one side) in the width direction is out of the scope of the present application.
Further, the other end in the longitudinal direction of the meandering prevention guide has a concave portion corresponding to the convex portion having the specific shape. Here, as described above, the meandering prevention guide according to the present invention is disposed with the longitudinal ends spaced apart from the belt body, so that the concave portion corresponding to the convex portion is attached to the convex portion. In this case, it is not necessary to match completely, as long as it is a state where at least the meandering prevention guide is blocked when viewed in a cross section in the width direction of the meandering prevention guide.
In this way, since the meandering prevention guide has a shape in which the concave portion and the convex portion correspond to both ends, positioning becomes easy when the both ends are spaced apart.

As described above, the meandering prevention guide 3 according to the present invention is strip-shaped and has a shape having a convex portion having a specific shape at one end and a concave portion corresponding to the concave portion at the other end.
Hereinafter, a specific example of the uneven shape will be described with reference to FIG. Here, Fig.3 (a)-(d) is a figure which shows the example of the uneven | corrugated shape of the both ends of the meander prevention guide in this invention.
As shown in FIGS. 3A to 3D, one end (left end portion in the figure) of the meandering prevention guide protrudes in the longitudinal direction and from both ends in the width direction toward the protruding tip. A convex portion having a tapered shape is provided, and a concave portion corresponding to the convex portion is provided at the other end (the right end portion in the drawing).

  The meandering prevention guide 3a shown in FIG. 3A has a triangular shape in which the convex portion 5a has an apex at the center in the width direction, and a V-shaped notch having the same shape as the convex portion 5a is formed as the concave portion 6a. ing. As described above, when the concave portion and the convex portion are brought together, the shape is perfectly matched, and since it is a simple shape, positioning is facilitated when both ends are arranged apart from each other. Can be suppressed.

  The meandering prevention guide 3b shown in FIG. 3B has an arc shape in which the convex portion 5b has an apex at the center in the width direction, and as a concave portion 6b, a V-shaped incision having an apex at the center in the width direction (FIG. 3 (a) is formed. Since such a convex part is formed in a curve and does not have a corner on its side surface, as shown in FIG. 4B, the projecting direction of the convex part is opposite to the rotation direction of the belt tubular body. Thus, it is possible to effectively suppress the groove formed on the roll support, the riding on the outer edge, and the catch.

  The meandering prevention guide 3c shown in FIG. 3C has a shape in which the convex portion 5c is formed with minute irregularities (jags) at the ends, and a cut having the same shape as the convex portion 5c is formed as the concave portion 6c. ing. Thus, it is a shape that perfectly matches when the concave portion and the convex portion are brought together, and the shape is complicated, so that the positioning accuracy is improved when arranging the both ends apart, Deviation can be minimized.

  The meandering prevention guide 3d shown in FIG. 3D has an acute angle with the convex portion 5d as a vertex at a position shifted from the center in the width direction, and the concave portion 6d has the same shape as the convex portion 5d. Is formed. As described above, when the concave portion and the convex portion are brought together, the shape is perfectly matched, and since it is a simple shape, positioning is facilitated when both ends are arranged apart from each other. Can be suppressed. Further, when the meandering prevention guide 3d is disposed apart as shown in FIG. 4 (d), the mechanical strength becomes higher on the upper side in the figure where the apex of the convex portion 5d exists. Therefore, peeling of the meandering prevention guide is effective when the upper edge (the edge close to the apex of the convex portion 5d) is placed along the inner side of the groove formed on the roll support body or the outer edge. The target can be effectively suppressed.

Next, with reference to FIG. 4, the arrangement | positioning state of the meander prevention guide shown by FIG. 3 (a)-(d) is demonstrated. Here, FIGS. 4A to 4D are plan views for explaining the arrangement state of the meandering prevention guide shown in FIGS. 3A to 3D.
As shown in FIGS. 4A to 4D, the meandering prevention guides 3a to 3d shown in FIGS. 3A to 3D are all separated with the concave portion and the convex portion attached to each other. Arranged.
The separation distance is appropriately determined depending on the size of the belt tubular body and the meandering prevention guide, the diameter of the support roll, and the like, but is usually preferably in the range of 1 to 7 mm, and more preferably in the range of 1 to 3 mm. preferable.
In addition, this separation distance shows the distance between the convex part and the recessed part in the same position of the width direction of a meandering prevention guide. That is, in FIGS. 4A, 4C, and 4D, the separation distance is 2 mm.
Further, when this separation distance changes at the measurement position in the width direction of the meandering prevention guide, it is a separation distance measured in parallel with the circumferential direction at the closest portion, for example, in the case of FIG. The separation distance is 1.5 mm.

Moreover, in the belt tubular body of the present invention, by arranging the meandering prevention guide having a specific convex portion and a concave portion corresponding to the specific convex portion as shown in FIGS. 4 (a) to (d), It is possible to eliminate guide joints in a pseudo manner. That is, when the meandering prevention guide has no convex part and concave part, if both ends thereof are arranged apart from each other, a state in which there is no meandering prevention guide as a joint can be formed in a certain region in the circumferential direction of the belt tubular body. In the belt tubular body of the present invention, by arranging the meandering prevention guide with the convex part and the concave part attached, it is possible to prevent a state where there is no meandering prevention guide in any region in the circumferential direction. it can.
Further, in the belt tubular body of the present invention, the meandering prevention guides are arranged apart from each other, so that stress concentration can be avoided at the joint at the time of repeated bending at the support roll portion.
Moreover, in the belt tubular body of the present invention, the convex portion of the meandering prevention guide is used in a state of facing the rotation direction (the arrow direction in FIG. 4), so that the convex portion does not have a sharp side or end. For this reason, it is possible to make it difficult for the support roller to catch on the groove and the outer edge at the joint between the convex portion and the concave portion.
From the above, even if the belt tubular body of the present invention is rotated in a state stretched by a support roller, the meandering prevention guide peels and breaks due to stress concentration at the joint of the meandering prevention guide. In addition, it is possible to prevent the belt from running over the groove or outer edge of the support roller, and as a result, it is possible to prevent sideways running and meandering for a long time without deteriorating the life of the belt. can do.

The convex portion of the meandering prevention guide according to the present invention has a length from the point of accuracy of fitting with the corresponding concave portion and handling of the meandering prevention guide itself (especially, when the concave portion is long, it becomes two or more thin guides). The length is preferably in the range of 2 to 15 mm, more preferably in the range of 3 to 10 mm, and still more preferably in the range of 4 to 8 mm.
Here, the length of a convex part shows the distance from the location where the width | variety of the meander prevention guide changed to the protrusion front-end | tip. In addition, when there are a plurality of protruding tips, it means the longest distance. For example, the meandering prevention guide 3c shown in FIG. 3C is 6 mm, and the meandering prevention guide 3d shown in FIG. 3D is 8 mm.

When a shifting force is generated in which the belt body 2 tries to move in the axial direction of the belt support roll, a reaction force (stress) having the same strength against the shifting force is directly applied to the meandering prevention guide 3. From the viewpoint that this stress can be dispersed and absorbed to some extent in the meandering prevention guide 3, the meandering prevention guide 3 is preferably an elastic member having a durometer hardness of A60 to A90, and the durometer hardness is A60 to A80. More preferably.
Here, the durometer hardness is measured using a type A durometer according to JIS K 6253, with the meandering prevention guide having a thickness of 6 mm. When the meandering prevention guide is less than 6 mm thick, the meandering prevention guide is laminated and measured so as to have a thickness of 6 mm.

  As the material constituting the elastic member, an elastic body having an appropriate hardness such as polyurethane, neoprene rubber, polyurethane rubber, silicone rubber, polyester elastomer, chloroprene rubber, nitrile rubber, or the like can be used. Among these, polyurethane rubber and silicone rubber are particularly preferably used in consideration of electrical insulation, moisture resistance, solvent resistance, ozone resistance, heat resistance, and wear resistance.

  In the present invention, the shape of the meandering prevention guide 3 can be determined as appropriate according to the use conditions of the belt tubular body, etc., but the meandering prevention guide 3 is substantially constant except for the vicinity of both end portions having the above-mentioned convex portions and concave portions. It has a width, and the width is preferably 1 to 10 mm, particularly preferably 4 to 7 mm, from the viewpoint of the meandering prevention effect and durability. The thickness is not particularly limited, but is preferably 1 to 5 mm, particularly preferably 3 to 5 mm, from the viewpoints of the meandering prevention effect and durability.

-Adhesive layer-
The adhesive layer 4 is a layer used for adhering the belt body 2 and the meandering prevention guide 3, and may be composed of an elastic adhesive, or a heat-sensitive sheet-shaped adhesive (heat-sensitive adhesive sheet). ).

  The elastic adhesive used for the adhesive layer 4 is an adhesive having a durometer hardness after the curing reaction in the range of A30 / S to A50 / S, and is mainly composed of an acrylic modified silicone polymer manufactured by Cemedine Co., Ltd. Super-XNo 8008, Cyflex 100 mainly composed of specially modified silicone polymer manufactured by Konishi Co., Ltd. can be mentioned, and acrylic modified silicone polymer manufactured by Cemedine Co., Ltd. from the viewpoint of adhesive strength with the belt body 2. Super-X No. 8008 containing as a main component is preferably used.

The heat-sensitive adhesive sheet used for the adhesive layer 4 is excellent in adhesiveness with the belt body 2 and the meandering prevention guide 3 to be used, and can obtain the thrust peel strength and T peel strength described later. Any adhesive that can be used is not particularly limited. Specifically, for example, an adhesive mainly composed of a resin material such as acrylic, silicon, natural or synthetic rubber, urethane, synthetic resin such as vinyl chloride / vinyl acetate copolymer is used. be able to.
More specifically, examples include polyester adhesive sheets GM-913 and GM-920 manufactured by Toyobo Co., Ltd., and polyester adhesive sheets D3600 manufactured by Sony Chemical Corporation. The polyester adhesive sheet D3600 manufactured by Sony Chemical Co., Ltd. and the polyester adhesive sheet GM-920 manufactured by Toyobo Co., Ltd. are preferably used based on the adhesive strength with the belt base material.

  The thickness of the adhesive layer 4 is preferably 0.01 to 0.3 mm, and more preferably 0.02 to 0.05 mm. If the thickness of the adhesive layer 4 is less than 0.01 mm, uniform adhesive strength may not be obtained. If the thickness exceeds 0.3 mm, the position of the meandering prevention guide 3 may be displaced by the pressure applied during bonding. It may happen.

  The meandering prevention guide 3 is manufactured by manufacturing a big mold having both ends provided with desired irregularities, placing the material of the meandering prevention guide on the big mold so as to have a desired thickness, and pressing it. Can be obtained.

  For the attachment of the meandering prevention guide 3 to the belt body 2 using the adhesive layer 4, the belt-like belt body 2 and the meandering prevention guide 3 may be attached, and then both ends of the belt body 2 may be adhered. The meandering prevention guide 3 may be bonded to the endless belt body 2.

The method for sticking the meandering prevention guide 3 to the belt body 2 is not particularly limited, but in general, in the case of adhesion using a heat sensitive adhesive sheet, the heat sensitive adhesive sheet is heated to the meandering prevention guide 3. After pressurizing and pasting, the release paper is peeled off, and then applied to the belt body 2 by heating and pressurizing.
When an elastic adhesive is used, a method is used in which the elastic adhesive is applied to the meandering prevention guide 3 and then bonded to the belt body 2 by being pressed against each other.

  In addition, it is important to bond without bubbles, and usually use a method such as bonding with a hand roller, rubber roller, press, etc., bonding under reduced pressure, bonding under pressure, etc. Can do. Further, the surface of the meandering prevention guide 3 or the belt main body 2 may be subjected to corona treatment, primer treatment, aging, or the like to improve the adhesive force.

  In FIG. 1, the meandering prevention guide 3 is affixed to the inner side surface of the belt body 2, but the affixing surface of the meandering prevention guide 3 depends on the application of the belt tubular body 1. It may be an outer surface.

-Thrust peel strength-
In the belt tubular body 1 of the present invention, the thrust peel strength of the bonded belt main body 2 and the meandering prevention guide 3 is preferably 5 N / mm or more, and more preferably 10 N / mm or more and 20 N / mm or less. . When the thrust peeling strength is 5 N / mm or more, problems such as displacement of the meandering prevention guide 3 or peeling due to long-time driving of the belt tubular body 1 are reduced. Further, when the thrust peel strength is 20 N / mm or less, there are few problems such as damage to the belt tubular body 1 due to the shearing force acting on the interface of the belt main body / adhesive layer / meander prevention guide when the belt tubular body is running. This is preferable.
A method for measuring the thrust peel strength will be described below. The measurement of the thrust peel strength and the measurement of the T-type peel strength described later are performed under the condition of 22 ° C.-55% RH.

FIG. 5 is an explanatory view of a thrust peel test, FIG. 5 (a) is a plan view showing the test piece 40, and FIG. 5 (b) is a view of the test piece 40 from the direction of arrow D in FIG. 5 (a). FIG. 5C is an explanatory view of the test method, showing a state before the test piece 40 is inserted into the belt fixing member 42, and FIG. 5D is a diagram showing the test piece 40 attached to the belt fixing member 42. The figure which shows the state inserted, FIG.5 (e) is a longitudinal cross-sectional enlarged view of FIG.5 (d).
As shown in FIG. 5 (a), the belt tubular body 1 is cut to produce a test piece 40 of 30 mm in the Y direction and 50 mm in the X direction on the drawing. Further, as shown in FIGS. 5C to 5E, the width W2 of the belt fixing member 42 used for the thrust peel strength test is 10 mm, and the belt main body through groove 44 and the meander prevention guide penetration are provided on the side surface. A groove 46 is formed. As shown in FIG. 5D, the belt main body 2 portion and the meandering prevention guide 3 portion of the test piece 40 are respectively formed in the belt main body through groove 44 and the meander prevention guide through groove 46 provided on the side surface of the belt fixing member 42. insert. After inserting the test piece 40 into the belt fixing member 42, the test piece 40 is pulled at a speed of 10 mm / min in the direction of arrow E shown in FIG. At that time, a thrust force (shearing force) acts on the bonding portion between the belt body 2 and the meandering prevention guide 3.
The force P2 (N) when the belt body 2 and the meandering prevention guide 3 are peeled is measured, and the thrust peel strength (P2 / P) is calculated from the measured P2 (N) and the width W2 (10 mm) of the fixing member 40. W2) (N / mm) is calculated.

-T-type peel strength-
In the belt tubular body 1 of the present invention, the T-type peel strength between the belt body 2 and the meandering prevention guide 3 bonded by the adhesive layer 4 is preferably 0.8 N / mm or more and 4 N / mm or less. More preferably, it is not less than mm and not more than 3 N / mm. When the T-type peel strength is 0.8 N / mm or more, problems such as displacement of the meandering prevention guide 3 and occurrence of peeling due to long-time driving of the belt tubular body 1 are reduced. On the other hand, when it is 4 N / mm or less, the belt tubular body 1 is less likely to be damaged by the shearing force acting on the interface of the belt main body / adhesive layer / meander prevention guide when the belt tubular body is running.
A method for measuring the T-peel strength will be described below.

FIG. 6 is an explanatory diagram of a T-type peel test. FIG. 6A shows a portion for producing the test piece 30 of the T-type peel test. FIG. 6B shows a side view of the test piece 30. FIG. 6C is an explanatory diagram of a test method for the T-type peel test.
As shown in FIG. 6A, the belt main body 2 was cut to the same width as the meandering prevention guide 3 having a width W1 to obtain a test piece 30 having a width W1 and a length of 50 mm. 6B-1 is a view of the test piece 30 as viewed from the direction of the arrow A, and FIG. 6B-2 is a view of the test piece 30 as viewed from the direction of the arrow B. FIG.
One end of the obtained test piece 30 is peeled off at the interface between the belt body 2 and the meandering prevention guide 3 as shown in FIG. 6C, the belt body 2 is fixed, and the meandering prevention guide 3 is moved in the direction of arrow C. The tensile force P1 (N) when it is pulled into a T-shape at a speed of 50 mm / min is measured. T-type peel strength (P1 / W1) (N / mm) is calculated using the measured P1 and W1.

The belt tubular body of the present invention can be applied to various belt devices, and its use is not particularly limited, but is preferably applied to an image forming apparatus, particularly an image forming apparatus using an electrophotographic system.
More specifically, the belt tubular body of the present invention is preferably applied to an intermediate transfer belt or a transfer conveyance belt in an image forming apparatus using an electrophotographic system.

<Image forming apparatus>
The image forming apparatus according to the present invention includes an image carrier, a charging unit that charges the surface of the image carrier, a latent image forming unit that forms a latent image on the surface of the image carrier, and the latent image formed by toner. Development means for developing and forming a toner image; transfer means for transferring the toner image to a recording medium; and fixing means for fixing the toner image to the recording medium, wherein at least one of the means includes: The belt tubular body according to claim 1, and a plurality of support rolls that rotatably support the belt tubular body. In addition, it is a preferable aspect that at least one of the plurality of support rolls has a groove for aligning the meandering prevention guide.
The configuration of the image forming apparatus is not particularly limited. For example, a normal monocolor image forming apparatus that contains only a single color toner in the developing device, or a toner image held on an image holding body such as a photosensitive drum is used. Examples thereof include a color image forming apparatus in which primary transfer is sequentially performed on an intermediate transfer body, and a tandem color image forming apparatus in which a plurality of image holding bodies each having a developing device for each color are arranged in series on the intermediate transfer body.

First, the relationship between the image forming apparatus and the belt tubular body of the present invention will be described with reference to FIG. 7A is a perspective view for showing the support roll 21 provided with the groove 20, and FIG. 7B is a support roll 21 provided with the groove 20 in FIG. 7A. It is a principal part expanded sectional view when this is cut | disconnected by the axial direction.
In the image forming apparatus of the present invention, the belt tubular body (belt tubular body of the present invention) 1 shown in FIGS. 1 and 2 is provided with a groove 20 as shown in FIGS. 7 (a) and 7 (b). It is preferably stretched by a certain support roll 21. The groove 20 is provided for regulating (regulating) the meandering prevention guide 3, and as shown in FIG. 7C, the meandering prevention guide 3 in the belt tubular body 1 of the present invention with respect to the groove 20. The belt tubular body 1 can be prevented from running or meandering by being fitted and being restricted from moving.
Further, the belt tubular body of the present invention may be stretched so as to circumscribe the meandering prevention guide at the edge of the support roll. In this case, the meandering prevention guide 3 is restricted by the side end (edge) of the support roll, so that the belt tubular body can be prevented from running or meandering.

  Hereinafter, as an example of an image forming apparatus of the present invention, with reference to the drawings, a sheet conveying belt type image forming apparatus using the belt tubular body of the present invention, and an intermediate transfer body using the belt tubular body of the present invention An image forming apparatus of the type will be described.

First, a color image forming apparatus that repeats primary transfer is shown as an example of the image forming apparatus of the present invention. FIG. 8 is a schematic configuration diagram showing an example of the image forming apparatus of the present invention.
The image forming apparatus shown in FIG. 8 includes a photosensitive drum 101 as an image carrier, an intermediate transfer belt 102 as an intermediate transfer member, a bias roller 103 as a transfer electrode, a tray 104 for supplying paper as a transfer target, BK (Black) toner developing device 105, Y (yellow) toner developing device 106, M (magenta) toner developing device 107, C (cyan) toner developing device 108, belt cleaner 109, peeling claw 113, belt support roll 121, 123 and 124, a backup roller 122, a conductive roller 125, an electrode roller 126, a cleaning blade 131, a sheet bundle 141, a pickup roller 142, and a feed roller 143. The body is used.
The meandering prevention guide provided on the inner side of the intermediate transfer belt 102 is located along a groove provided in the belt support rolls 121, 123, and 124, or side edge portions of the belt support rolls 121, 123, and 124. The intermediate transfer belt 102 is guided by the meandering prevention guide when the belt is running. Therefore, the intermediate transfer belt 102 can prevent the problem of meandering during belt running.

  In the image forming apparatus shown in FIG. 8, the photosensitive drum 101 rotates in the direction of arrow F, and its surface is uniformly charged by a charging device (not shown). An electrostatic latent image of the first color (for example, BK) is formed on the charged photosensitive drum 101 by image writing means such as a laser writing device. The electrostatic latent image is developed with toner by the developing device 105 to form a visualized toner image T. The toner image T reaches the primary transfer portion where the conductive roller 125 is arranged by the rotation of the photosensitive drum 101, and the toner image T is statically moved by applying an electric field having a reverse polarity to the toner image T from the conductive roller 125. Primary transfer is performed by rotation of the intermediate transfer belt 102 in the direction of arrow G while being electrically attracted to the intermediate transfer belt 102.

  Similarly, a second color toner image, a third color toner image, and a fourth color toner image are sequentially formed and superimposed on the intermediate transfer belt 102 to form a multiple toner image.

  The multiple toner image transferred to the intermediate transfer belt 102 reaches the secondary transfer portion where the bias roller 103 is installed by the rotation of the intermediate transfer belt 102. The secondary transfer unit includes a bias roller 103 disposed on the surface side where the toner image of the intermediate transfer belt 102 is held, a backup roller 122 disposed so as to face the bias roller from the back side of the intermediate transfer belt 102, and the backup roller 122. It is composed of an electrode roller 126 that rotates in pressure contact with the roller 122.

  The sheets 141 are picked up one by one from the sheet bundle accommodated in the sheet tray 104 by the pickup roller 142, and are fed at a predetermined timing between the intermediate transfer belt 102 and the bias roller 103 of the secondary transfer unit by the feed roller 143. Sent. A toner image held on the intermediate transfer belt 102 is transferred to the fed paper 141 by pressure contact conveyance by the bias roller 103 and the backup roller 122 and rotation of the intermediate transfer belt 102.

  The paper 141 onto which the toner image has been transferred is peeled off from the intermediate transfer belt 102 by operating the peeling claw 113 at the retracted position until the primary transfer of the final toner image is completed, conveyed to a fixing device (not shown), and pressurized / heated. The toner image is fixed by the processing to be a permanent image. The intermediate transfer belt 102 after the transfer of the multiple toner image to the paper 141 is completed for removal of residual toner by a belt cleaner 109 provided downstream of the secondary transfer unit to prepare for the next transfer. The bias roller 103 is attached so that a cleaning blade 131 made of polyurethane or the like is always in contact with it, and foreign particles such as toner particles and paper dust adhered by transfer are removed.

In the case of transfer of a single color image, the primary transferred toner image T is immediately secondarily transferred and conveyed to a fixing device. Therefore, the rotation of the intermediate transfer belt 102 and the photosensitive drum 101 is synchronized so that the toner images of the respective colors do not shift so as to coincide with each other accurately. In the secondary transfer section, an output pressure (transfer voltage) having the same polarity as the polarity of the toner image is applied to the electrode roller 126 that is in pressure contact with the backup roller 122 disposed opposite to the bias roller 103 via the intermediate transfer belt 102. The toner image is transferred to the paper 141 by electrostatic repulsion.
As described above, an image can be formed.

Next, another example of the image forming apparatus of the present invention is shown.
The image forming apparatus shown in FIG. 9 includes image forming units Y, M, C, and BK (not shown) including the photosensitive drums 201Y, 201M, 201C, and 201BK, a paper conveyance belt 206, transfer rollers 207Y, 207M, 207C, 207BK, belt support rolls 210 and 211, a paper transport roll (not shown), and a fixing device (not shown). As the paper conveying belt 206, the belt tubular body of the present invention is used.
Here, the photoconductive drums 201Y, 201M, 201C, and 201BK and the transfer rolls 207Y, 207M, 207C, and 207BK are arranged in a substantially vertical direction with respect to the paper transport belt 206.

A meandering prevention guide provided on the inner side (inner peripheral side) of the paper conveying belt 206 is in contact with a side edge portion of the belt support rolls 210 and 211 or is fitted into a groove formed in the support rolls 210 and 211. As a result, the problem of meandering during belt running can be prevented.
When the belt tubular body of the present invention is applied to the paper conveying belt 206, the belt support roll for supporting the belt can be used without a problem that the meandering prevention guide peels even when the outer diameter of at least one of the belt support rolls is 14 to 20 mm. it can.

  The photosensitive drums 201Y, 201M, 201C, and 201BK can be rotated at a predetermined peripheral speed (process speed). Around the periphery, for example, a corotron charger (not shown) and an exposure unit (not shown) Each color developing device (not shown) and a photosensitive drum cleaner (not shown) are preferably arranged.

  Further, the four photosensitive drums 201Y, 201M, 201C, and 201BK are arranged in parallel in the order of Y, M, C, and BK with respect to the paper conveying belt 206. The order of the photosensitive drums 201Y, 201M, 201C, and 201BK depends on the image forming method. An appropriate order can be set together.

  The paper transport belt 206 can be rotated counterclockwise by belt support rolls 210 and 211 at the same peripheral speed as the photosensitive drums 201Y, 201M, 201C, and 201BK. The paper transport belt 206 may be provided with a belt cleaning device (not shown).

  The transfer rolls 207Y, 207M, 207C, and 207BK are disposed inside the paper transport belt 206 and at positions facing the portions where the paper transport belt 206 is in contact with the photosensitive drums 201Y, 201M, 201C, and 201BK, respectively. A transfer region for transferring the toner image onto a sheet (transfer object) is formed.

A paper transport roll (not shown) transports the paper (transfer object) to the paper transport belt 206.
The paper (transferred material) conveyed to the paper conveyance belt 206 passes through a transfer area between the paper conveyance belt 206 and the photosensitive drums 201Y, 201M, 201C, 201BK,
It is conveyed to a fixing device (not shown).

  The transfer cycle in the image forming apparatus shown in FIG. 9 will be described by taking the image forming unit BK having the photosensitive drum 201BK as an example. The surface of the rotating photosensitive drum 201BK is uniformly charged to a predetermined polarity / potential using a corotron charger (not shown). The photosensitive drum 201BK whose surface is uniformly charged is then exposed imagewise by an exposure device (not shown) to form an electrostatic latent image on the surface.

  Subsequently, the electrostatic latent image is developed by a black developing device (not shown), so that a toner image is formed on the surface of the photosensitive drum 201BK. The toner at this time may be a one-component toner or a two-component toner.

On the other hand, the sheet (transfer object) is electrostatically attracted to the sheet conveyance belt 206 and conveyed to the transfer region between the photosensitive drum 201BK and the sheet conveyance belt 206. In this transfer area, the toner image formed on the surface of the photosensitive drum 201BK is transferred to the surface of the sheet (transfer object) by an electric field formed by a transfer bias applied from the transfer roll 207BK.

  Thereafter, the toner remaining on the photosensitive drum 201BK is cleaned and removed by a photosensitive drum cleaner (not shown). Then, the photosensitive drum 201BK is subjected to the next transfer cycle.

The above transfer cycle is similarly performed in the image forming units C, M, and Y.
That is, by the transfer cycle as described above, the sheet (transfer object) onto which the toner images of each color are sequentially transferred by the transfer rolls 207BK, 207C, 207M, and 207Y is conveyed to a fixing device (not shown). Fixing is performed.
Thus, a desired image is formed on the sheet (transfer object).

  As described above, the intermediate transfer belt and the sheet conveying belt have been described as an example of the belt tubular body. However, the present invention is not limited thereto, and other means such as an image forming apparatus using an image carrier belt instead of the image carrier. The present invention can also be applied to. Further, since the image forming apparatus of the present invention uses the belt tubular body of the present invention that can prevent peeling of the meandering prevention guide from the belt main body, the belt tubular body can be deviated or meandered to reduce the belt life. It can be easily and reliably prevented for a long time without incurring. Moreover, since the belt tubular body of this invention can be supported and used by the support roll whose outer diameter is 14-20 mm (preferably 16-20 mm), at least 1 of said several support roll is used. Since the support roll can have an outer diameter of 14 to 20 mm, the image forming apparatus can be downsized.

EXAMPLES Hereinafter, although this invention is demonstrated further in detail using an Example, this invention is not limited by the following Example.
(Example 1)
<Preparation of belt body 2>
The belt body 2 in the present invention uses a solvent-soluble polyamideimide resin: manufactured by Toyobo Co., Ltd., Viromax HR16NN (solid content: 18% by mass, solvent: methyl-2-pyrrolidone) as the polyamideimide resin, As a conductive agent, carbon black (Degisa Co., Ltd. Special Black 4: pH 3. Volatile content: 14% by mass) was added at 25 parts by mass per 100 parts by mass of the resin component, and a disperser (Genus Co., Ltd.) was used. To obtain a coating solution. This coating solution is applied to the outer surface of an aluminum pipe having an outer diameter of 168 mm, spin-dried at 150 ° C. for 30 minutes, and then heated at 250 ° C. for 1 hour to form a polyamideimide resin belt having an outer diameter of 168 mm and a width of 368 mm (endless shape). A belt body 2) was obtained. The surface resistivity of this belt was 1.1 × 10 ¹² Ω / □.

<Meander prevention guide 3>
As a material for the meandering prevention guide, a thermosetting urethane sheet (Tigers Polymer Co., Ltd. Typelen TR100-70) having a thickness of 1 mm and a JIS hardness of 70 degrees is used. As shown in FIG. A meandering prevention guide having a width of 5 mm, a triangular convex portion (length: 6 mm) at one end, and a V-shaped cut-out concave portion at the other end was prepared.

<Production of belt tubular body with meandering prevention guide>
Super-X No. 8008 mainly composed of an acrylic-modified silicone polymer manufactured by Cemedine Co., Ltd. was applied as an elastic adhesive to the obtained meandering prevention guide in a thickness of 20 μm, and then the inner surface of the belt on one side of the polyamideimide resin belt And a belt tubular body with a meandering prevention guide was manufactured by applying a pressure of 0.03 Mpa. When the meandering prevention guide is arranged, as shown in FIG. 4A, the convex part and the concave part of the meandering prevention guide are brought into contact with each other, and the separation distance is set to 2 mm.

(Example 2)
As the meandering prevention guide, except that a guide having a width of 5 mm and a convex part having a circular arc shape (length: 9 mm) and a V-shaped notched concave part as shown in FIG. 3B was used. In the same manner as in Example 1, as shown in FIG. 4B, a belt tubular body with a meandering prevention guide having an average separation distance of 1.5 mm was manufactured.

(Example 3)
As a meandering prevention guide, as shown in FIG. 3 (c), a convex portion having a width of 5 mm and a jagged tip (length: 6 mm, length of a small mountain: 2 mm) and a notch having the same shape as the convex portion were provided. A belt tubular body with a meandering prevention guide having a separation distance of 2 mm was produced as shown in FIG. 4C in the same manner as in Example 1 except that one having a recess was formed.

Example 4
As a meandering prevention guide, as shown in FIG. 3 (d), a convex portion having a width of 5 mm and having an acute angle with a position shifted from the center in the width direction, and a concave portion provided with a cut of the same shape as the convex portion A belt tubular body with a meandering prevention guide having a separation distance of 2 mm was manufactured as shown in FIG.

(Comparative Example 1)
As shown in FIG. 10A, the meander prevention guide is the same as in Example 1 except that one having a width of 5 mm and not having a convex portion and a concave portion at both ends is used. As shown, a belt tubular body with a meandering prevention guide having a separation distance of 2 mm was produced.

(Comparative Example 2)
As shown in FIG. 11 (a), the meander prevention guide is the same as in Example 1 except that a guide having a shape with a width of 5 mm and both ends obliquely cut is used. As shown, a belt tubular body with a meandering prevention guide having a separation distance of 2 mm was produced.

(Evaluation)
Two metal rolls having an outer diameter of 25 mm are provided between two metal rolls of a metal roll 210 having an outer diameter of 18 mm and a metal roll 211 having an outer diameter of 28 mm, which are driven by a belt. The belts with meandering prevention guides 1 to 4 and Comparative Examples 1 and 2 were respectively suspended by applying a tension of 50 N and rotated at a rotation speed of 15 revolutions / minute, and the durability of the belt with meandering prevention guides was tested. The four metal rolls are provided with grooves for regulating the meandering prevention guide as shown in FIG. Note that the belts with meandering prevention guides of Examples 1 to 4 and Comparative Examples 1 to 2 are stretched so that the arrow directions shown in FIGS. 4, 10, and 11 are rotational directions.
The test was completed at 10,000 K rotation when the meandering-prevented guide belt did not break.

  It was confirmed that the belt tubular bodies with meandering prevention guides of Examples 1 to 4 had no problem in durability even when rotated 10,000K. In contrast, the belt with the meandering prevention guide of Comparative Example 1 was observed to peel off at the end of the meandering prevention guide at 8K rotation. In Comparative Example 2, peeling of the end portion of the meander prevention guide was not observed, but the belt behavior became abnormal at 400 K rotation, and as a result of observation, tearing (breaking) was confirmed near the joint of the guide.

  In addition, about the belt tubular body with the meandering prevention guide of Examples 1-4 and Comparative Examples 1-2, when the thrust peeling strength was measured by the above-mentioned method, all showed the value of 10 N / mm or more, and sufficient It was found to have strength.

  As a result, the belt tubular body of the present invention can prevent offset running and meandering over a long period of time without causing a reduction in the life of the belt. It can also be seen that by using this belt tubular body, it is possible to provide an image forming apparatus that is highly reliable and can be miniaturized.

1 is a schematic configuration diagram of a belt tubular body of the present invention. In the belt tubular body of FIG. 1, it is a principal part expanded sectional view for demonstrating the arrangement | positioning state of the meander prevention guide with respect to a belt main body. It is a figure which shows the example of the uneven | corrugated shape of the both ends of the meander prevention guide in this invention. It is a schematic plan view for demonstrating the arrangement | positioning state of the meander prevention guide shown by Fig.3 (a)-(d). It is explanatory drawing of a thrust peeling test. It is explanatory drawing of a T-type peeling test. It is the schematic which shows the relationship between the belt tubular body of this invention, and the support roll which has a groove | channel. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus of the present invention. It is a schematic block diagram which shows the principal part of the other example of the image forming apparatus of this invention. It is a schematic plan view for demonstrating the shape and arrangement | positioning state of the meander prevention guide of the comparative example 1. It is a schematic plan view for demonstrating the shape of the meander prevention guide of the comparative example 2, and the arrangement | positioning state.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Belt tubular body 2 Belt main body 3 Meander prevention guide 4 Adhesive layers 5a-5d Convex part 6a-6d Concave part 20 Groove 21 Support roll 30 Test piece 40 (for thrust peel test) Test piece 42 Belt fixation Member 44 Belt body through groove 46 Meander prevention guide through groove 102 Intermediate transfer belt 206 Paper transport belt

Claims (2)

An endless belt main body, and a meandering prevention guide disposed along the edge of at least one side of the belt main body and spaced at both ends in the longitudinal direction;
One end in the longitudinal direction of the meandering prevention guide protrudes in a direction perpendicular to the width direction and parallel to the longitudinal direction, and both ends in the width direction are tapered toward the tip of the protrusion. And a belt tubular body characterized in that the other end has a concave portion corresponding to the convex portion. An image carrier, charging means for charging the surface of the image carrier, latent image forming means for forming a latent image on the surface of the image carrier, and developing the latent image with toner to form a toner image Development means, transfer means for transferring the toner image to a recording medium, and fixing means for fixing the toner image to the recording medium,
An image forming apparatus, wherein at least one of the means includes the belt tubular body according to claim 1 and a plurality of support rolls that rotatably support the belt tubular body.

Images