JP2006300985A - Endless belt for electrophotography - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an endless belt for electrophotography which never peels off a primary endless belt on the whole including an end of a bead for meander prevention even when placed in a severe environment of, for example, a temperature of 70°C and a relative humidity of 90%. <P>SOLUTION: The endless belt 10 for electrophotography is characterized in that when wet heat aging is carried out for 72 hours in the environment of the temperature of 70°C and the absolute humidity of 90% while the primary endless belt body 11 and bead 12 for meander prevention are bonded, the absolute value of the difference between the peripheral size variation ratio of the endless belt 10 during the wet heat aging and the size variation ratio of the overall length of the bead 12 for meander prevention during the wet aging is 0.5% or less. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  In the present invention, at least one or more substantially meandering bead for preventing meandering having a uniform cross section along one side or both ends of the inner peripheral surface of the endless belt body having flexibility is bonded. The present invention relates to an electrophotographic endless belt (hereinafter simply referred to as “endless belt”) used in an electrophotographic copying machine, a laser printer, a facsimile machine, or an OA apparatus combining these.

  For example, as shown in FIG. 6, the conventional endless belt 110 includes an endless belt main body 111 and a meander-preventing bead 112 that is bonded in the circumferential direction along the side portion of the inner peripheral surface of the endless belt main body 111. It is wound between two rollers 113 and 114 and used as an intermediate transfer belt.

  The endless belt body 111 is made of a flexible material that can be bent and is endlessly formed in the running direction. However, the meander-preventing bead 112 is not an endless molded product, but is formed in an elongated linear shape. Bonded along the side of the peripheral surface, both ends are opposed to each other in the circumferential direction to form a seam.

  The endless belt 110 formed in this way travels while the meandering prevention bead 112 is fitted in the fitting groove 115 formed at the end of the outer peripheral surface of the roller 114, so that the two rollers 113 and 114 rotate. Travel without meandering. However, as the endless belt 110 continues to be used for a long period of time, the meander-preventing bead 112 may peel from the endless belt main body 111 and the endless belt 110 may come off the rollers 113 and 114.

  Therefore, as an invention of the endless belt 110 for preventing the meander-preventing bead 112 from peeling from the endless belt main body 111, there is one described in Patent Document 1. In this Patent Document 1, a substantially linear guide (meandering prevention bead) is adhered in the circumferential direction by an adhesive layer on at least one side of an inner peripheral surface of an endless seamless belt (endless belt). A seamless belt (endless belt) with a guide (meandering prevention bead) in which both ends of the prevention bead are opposed to each other with a gap between the inner peripheral surface of the seamless belt (endless belt) and the guide (meandering prevention) With a guide (meandering prevention bead), characterized in that at least one end of the bead) is adhered with an adhesive and at least a part of the end exposed surface of the adhesive layer is covered with the adhesive. A seamless belt (endless belt) is described.

According to this, it is possible to suppress and prevent peeling of the end portion of the guide (meandering prevention bead) due to the action of the shear stress, and to eliminate the possibility that the guide (meandering prevention bead) comes off from the roll or the like through this. Are listed.
JP 2003-128295 A

  That is, in the invention described in Patent Document 1, the meander-preventing bead performs the same function as that formed continuously by connecting the joints formed by opposing both ends to each other with an adhesive. Thus, the end of the meander-preventing bead is prevented from peeling off from the endless belt body.

  However, when the endless belt is used in an electrophotographic apparatus, the end of the meander-preventing bead is caused by the endless belt being used for a long time in a high temperature environment reaching about 70 ° C. near the transfer device. There is a possibility that the other parts may peel off from the endless belt body.

  Therefore, an object of the present invention is for electrophotography in which the whole including the end portion of the meander-preventing bead does not peel from the endless belt body even under a severe environment such as a temperature of 70 ° C. and a relative humidity of 90%. It is to provide an endless belt.

  In order to achieve the above object, the invention according to claim 1 is a substantially linear shape having a uniform cross section along one side or both ends of the inner peripheral surface of a flexible endless belt body. An endless belt for electrophotography to which at least one meandering bead is adhered, wherein the meandering bead is composed of two layers in which an elastic material layer and a rigid material layer are adhered, and the endless belt The electrophotographic endless belt is characterized in that the rigid material layer of the meandering prevention bead is bonded to the inner peripheral surface of the belt main body.

  The invention according to claim 2 is characterized in that, in addition to the structure according to claim 1, the elastic material layer is made of polyurethane and the rigid material layer is made of polyethylene terephthalate.

  According to a third aspect of the present invention, when the endless belt body and the meander-preventing bead are bonded, when wet heat aging is performed for 72 hours in an environment of a temperature of 70 ° C. and a relative humidity of 90%, before and after the wet heat aging. The difference between the dimensional change rate in the circumferential direction of the endless belt generated in step 1 and the dimensional change rate in the longitudinal direction of the meandering prevention bead generated before and after the wet heat aging is 0.5% or less. It is an endless belt.

  According to a fourth aspect of the present invention, in addition to the configuration according to the third aspect, the meandering prevention bead has a dimensional change rate in the longitudinal direction occurring between before and after the wet heat aging of -0.5% to + 0.5%. It is characterized by being.

According to a fifth aspect of the present invention, in addition to the configuration of the third or fourth aspect, the meander-preventing bead is composed of two layers in which an elastic material layer and a rigid material layer are bonded to each other, and the elastic material A layer is laminated and bonded to the rigid material layer, and the tensile stress in the longitudinal stretching direction of the rigid material layer when the temperature of the rigid material layer is 80 ° C. is set to 1.0 to 8.5 N / mm ² during the lamination process. It is characterized by that.

  According to the first and second aspects of the present invention, since the elastic material layer has durability and wear resistance, the meandering-preventing bead can meander the endless belt while running as usual. The rigid material layer is provided between the inner peripheral surface of the endless belt body and the elastic material layer with dimensional stability and rigidity, and prevents the elastic material layer from expanding and contracting due to wet heat aging. Since the rigid material layer having a small amount of deformation and excellent dimensional stability is suppressed, it is possible to prevent the meander-preventing bead from peeling or cracking on the inner peripheral surface of the endless belt body.

  According to the invention of claim 3, when the endless belt is bonded to the meandering prevention bead and the endless belt is subjected to wet heat aging for 72 hours in an environment of a temperature of 70 ° C. and a relative humidity of 90%, Since the absolute value of the difference between the dimensional change rate in the circumferential direction of the endless belt before and after wet heat aging and the dimensional change rate in the longitudinal direction of the meandering prevention bead is 0.5% or less, the endless belt and the meandering prevention Since the difference in the degree of expansion and contraction occurring before and after wet heat aging is reduced with the bead, the bead for preventing meandering even when the endless belt for electrophotography is placed in a harsh environment such as a temperature of 70 ° C. and a relative humidity of 90%. It is possible to prevent the whole including the end of the belt from peeling off from the endless belt body.

  By preventing the peeling phenomenon that the meander-preventing bead floats up or shifts from the endless belt body due to changes in wet heat, the endless belt is less likely to be wavy, and this endless belt is used in an electrophotographic apparatus and incorporated in a roller. In some cases, traveling in an appropriate torque range can be maintained, so that the operation of the electrophotographic apparatus can be stably maintained.

  According to the invention described in claim 4, the meander-preventing bead has a small degree of expansion and contraction in the longitudinal direction that occurs before and after wet heat aging, and is −0.5% to + 0.5%. The peeling phenomenon in which the prevention bead is lifted or displaced from the endless belt main body due to a change in wet heat is further reliably prevented.

According to the fifth aspect of the present invention, the elastic material layer is laminated and bonded to the rigid material layer, and at the time of laminating, the rigid material layer is 1.0 to 8.5 N / in the longitudinal stretching direction at 80 ° C. A meander-preventing bead is produced by applying a tensile stress at mm ² . In order to produce by applying such tensile stress, when the elastic material layer is laminated to the rigid material layer and the meandering prevention bead is cooled, no residual stress remains in the meandering prevention bead and The bead no longer shrinks. On the other hand, if no tensile stress is applied, the rigid material layer may be bent on the inner peripheral surface of the endless belt body. Therefore, it does not bend. Therefore, the endless belt can be finished by satisfactorily bonding the meander-preventing bead on the inner peripheral surface of the endless belt body.

  Embodiments of the present invention will be described below. 1 to 5 show an embodiment of the present invention.

  First, the configuration will be described. As shown in FIG. 1, the endless belt 10 has a flexible endless belt body 11 and a uniform cross section along one side of the inner peripheral surface of the endless belt body 11. The substantially meandering bead 12 for preventing meandering is provided.

  The endless belt body 11 has an endless belt formed seamlessly and has an annular cross section. The endless belt body 11 is wound between a roller 13 and a roller 14 as shown in FIG. ing. The roller 14 is formed with a fitting groove 15 into which the meandering prevention bead 12 is fitted on the end portion side of the circumferential surface. Therefore, as the rollers 13 and 14 rotate, the endless belt 10 runs without meandering while the meander-preventing bead 12 is fitted in the fitting groove 15.

  Examples of the resin material used for the endless belt main body 11 include polyester resins such as polyethylene terephthalate (PET), PBT, and PEN, polyimide resins, polyimide amide resins, polyamide resins, fluororesins, polysulfone, polyethersulfone, Resins with small thermal deformation such as polycarbonate, aramid resin, PEEK, epoxy resin, cross-linked polyester resin, and melamine resin can be used.

  In addition, as a conductivity imparting agent that is selectively used to adjust the conductivity of the endless belt body 11, metallic powders such as needles, spheres, plates, and irregular shapes made of metal, metal compounds, and alloys can be used. And carbon powders such as acetylene black, ketjen black and furnace black, graphite powders such as natural graphite, artificial graphite and expanded graphite, ceramic powders, and various particles whose surfaces are metal-plated. The size of these conductivity-imparting agents is preferably about 0.01 to 10 μm from the viewpoint of dispersibility in the resin material. The amount of the conductivity-imparting agent depends on the degree of conductivity, but is in the range of about 5 to 25% by volume. Is preferred. This is because if the amount is less than 5% by volume, the distance between the conductive materials is large, so that the conductivity is not expressed. If the amount exceeds 25% by volume, the strength of the endless belt body 11 may be adversely affected. The conductivity-imparting agent is dispersed in the resin material by a known dispersion method using a mixing roll, a pressure kneader, an extruder, a three-roller, a homogenizer, a ball mill, a bead mill, or the like.

  In addition, although this embodiment shows what added the electroconductivity imparting agent to the resin material, besides this, a plasticizer, a coloring agent, an antistatic agent, an anti-aging agent, an antioxidant, a reinforcing filler, a reaction aid. It is possible to add additives such as reaction inhibitors as necessary.

  As shown in FIG. 3, the meander-preventing bead 12 is composed of two layers of an elastic material layer 16 and a rigid material layer 17, and the elastic material layer 16 is laminated and bonded to the rigid material layer 17. Yes. The rigid material layer 17 side of the meander-preventing bead 12 is bonded to the inner peripheral surface side of the endless belt body 11 by an acrylic double-sided pressure-sensitive adhesive layer 18.

  The elastic material layer 16 is made of a material having durability and wear resistance, and the rigid material layer 17 is made of a material having dimensional stability and rigidity against a heat change.

  In the embodiment of the present invention, the bonding method between the rigid material layer 17 and the endless belt body 11 is to bond the rigid material layer 17 and the endless belt body 11 with the acrylic double-sided pressure sensitive adhesive 18. However, as long as it can be bonded, it may be bonded using another adhesive, or may be bonded using a double-sided tape.

  The elastomer material constituting the elastic material layer 16 includes an olefin elastomer, a urethane elastomer, a vinyl chloride elastomer, a styrene elastomer, a polyester elastomer, a polyamide elastomer, a syndiotactic 1-2 elastomer, and a chlorinated ethylene copolymer crosslinked. Polymer alloy, chlorinated polyethylene, ester / halogen polymer alloy type elastomer, NBR, ABS, isopropylene rubber, fluoroelastomer, EPDM, chloroprene rubber (CR), SBR, fluoro rubber (FPM), silicone rubber, etc. are used. .

  The film material constituting the rigid material layer 17 includes polyester resins such as polyethylene terephthalate (PET), PBT, and PEN, polyimide resins, polyimide amide resins, polyamide resins, fluororesins, polysulfone, polyethersulfone, Polycarbonate, aramid resin, PEEK, epoxy resin, cross-linked polyester, melamine resin and the like are used.

  Such an endless belt 10 is manufactured as follows.

  First, in order to produce the base material of the endless belt body 11, a fluid solution made of polyamideimide is prepared.

  In preparing this material, the equivalent of trimellitic anhydride and 4,4-diaminodiphenylmethane was melted in dimethylacetamide and heated to react with a solid content concentration (substantially fully ring-closed polyamideimide) of 28% by mass. A group polyamideimide solution was obtained. Dimethylacetamide was added thereto to obtain a polyamideimide solution having a solid content concentration of 15% by mass and a solid content specific gravity of 1.2.

  Next, the base material of the endless belt body 11 is produced by injecting this polyamideimide solution into the inner periphery of the rotational molding die.

  In order to prevent material leakage by using a mold having an inner diameter of 226 mm, an outer diameter of 246 mm, and a length of 400 mm, the inner surface of which is mirror-polished by polishing, a ring-shaped ring with an inner diameter of 170 mm and an outer diameter of 250 mm is provided at both ends of the mold. Insert the lids. After injecting 190 g of material into this mold and maintaining the atmospheric temperature at 80 ° C. with a hot air dryer, adjusting the speed of 1000 rpm so that the thickness of the belt base material is about 100 μm, and rotating and molding for 30 minutes, The belt base material was dried by putting it into an oven at the temperature and time shown in each Example and Comparative Example described later together with the mold.

  After removing the mold from the oven, the mold was cooled at room temperature, and the belt base material was removed from the mold using the difference in thermal expansion between the mold and the belt base material. Then, both end portions of the belt base material were cut to a width of 240 mm, and an endless belt main body 11 having a thickness of about 100 μm was produced and used for the endless belt 10 shown in each example and comparative example described later.

  Further, the meander-preventing bead 12 having a two-layer structure is manufactured by the following procedure.

  First, a PET film having a width of 1000 mm and a thickness of 100 μm, which is a rigid material layer (Lumirror S10 # 100, manufactured by Toray Industries, Inc.) is placed between a cooling roll and a take-up roll under the conditions of Examples and Comparative Examples described later. A thermoplastic urethane resin (manufactured by Nippon Milactolan Co., Ltd., E180), which was set in a film molding machine with adjusted winding tension and heated and melted to 120 ° C. to become an elastic material layer, was formed with a thickness of 0. The film was extruded to 9 mm and laminated to a PET film to obtain a two-layer bead original.

  Then, a meander-preventing bead 12 having a length of 707 mm in the longitudinal direction (MD, Machine Direction) and a length of 5 mm in the lateral direction (TD, Transverse Direction) was cut out from the bead original fabric using a Thomson blade.

In the bead original fabric, the tensile stress in the longitudinal stretching direction of the rigid material layer at a temperature of 80 ° C. is set to 1.0 to 8.5 N / mm ² at the time of laminating.

  In this manner, a meander-preventing bead having a two-layer structure using a PET film as the rigid material layer 17 and a thermoplastic urethane resin as the elastic material layer 16 was produced. The meander-preventing bead 12 is bonded to one side surface of the inner peripheral surface of the endless belt main body 11 via an acrylic double-sided pressure-sensitive adhesive 18 having no core material, and the endless belts 10 of Examples and Comparative Examples to be described later are attached. Produced. At this time, the interval between the seams of the meandering prevention bead 12 was set to 3 mm.

  In the embodiment of the present invention, a tensile stress is applied to the rigid material layer 17. However, the present invention is not limited to the above embodiment as long as the dimensional stabilization of the meandering prevention bead 12 can be achieved. A method of relieving internal stress such as annealing may be employed.

  Further, in the embodiment of the present invention, a tensile stress is applied to the rigid material layer 17, but not limited to the above embodiment as long as the dimensional stabilization of the meandering prevention bead 12 can be achieved, You may design in consideration of the relationship between a temperature and the change of a drawing rate. The draw-down rate is represented by the ratio of the roll surface speed between rolls at the time of film formation, and is the ratio of the roll rotation speed when the roll diameter is the same. For example, it is assumed that there are rolls A and B having the same outer diameter during film formation. The film flows from the roll A to the roll B. When the number of rotations of each roll at this time is a and b, the value represented by the formula 100 × (b−a) / a is referred to as the withdrawal rate.

  When the elastic material layer 18 is laminated on the rigid material layer 17 to produce the meandering-preventive bead, if the flowing rigid material layer 17 is not stretched with a certain amount of tension, wrinkles, slack, etc. There is no clean bead stock that cannot be made. If the rigid material layer 17 is completely cooled, there is no problem even if tension is applied. However, when the lamination process is actually performed, heat is applied and softened. Internal stress remains, and the rate of dimensional change increases when heat is newly applied to the rigid material layer 17 after the formation of the rigid material layer 17. For this reason, it is necessary to manage the pulling rate in order to obtain the optimum tension.

  At the time of laminate molding, the rigid material layer 17 flows between a number of rolls, and the material temperature decreases in the process. At this time, the temperature profile and the internal stress profile are closely related.

  If the pulling rate between the rolls of the rigid material layer 17 near 80 ° C. is reduced, the rigid material layer 17 created under the conditions is up to about 80 ° C. even if the temperature is increased. The dimensional change rate of becomes smaller.

  Accordingly, since the magnitude of the internal stress applied in the process of gradually lowering the resin temperature of the rigid material layer 17 after the lamination process is reproduced as the magnitude of the heat shrinkage after becoming a product, it is actually used. Shrinkage can be suppressed by reducing the pulling rate from the temperature range where it is not desired to shrink to a slightly higher temperature (see Example 8 in Table 2).

  Next, regarding the dimension measurement method, the circumference measurement method of the endless belt 10 and the length measurement method of the meandering prevention bead will be described.

  The circumference of the endless belt 10 is measured by the circumference measuring apparatus shown in FIG. The endless belt 10 is wound around the precisely processed rollers 21 and 22 having an outer diameter of 25 mm, and the roller 21 is moved in the direction of the arrow while the roller 22 is fixed. give. The distance E between the rollers 21 and 22 is measured with a three-dimensional shape measuring instrument (Mitutoyo Co., Ltd., model BH506), and the circumference of the endless belt 10 is calculated from this equation, where belt circumference = 2 × E + 25π. To do.

  The length measurement method of the meandering prevention bead 12 is as follows. The meandering prevention bead 12 placed on a flat plate is pressed from above with a smooth glass plate, and in the same way as the endless belt, Measure the dimensions.

  The dimensional change rates of the endless belt 10 and the meander-preventing bead 12 are calculated from the dimensional measurement results before and after wet heat aging.

  First, the meander-preventing bead 12 is left in an environment of a temperature of 23 ° C. and a relative humidity of 50% for 3 hours without being bent in a state of being punched from the original bead. A dimension in the longitudinal direction of the meandering-preventing bead 12 left to stand for 3 hours is defined as A (mm).

  Next, the endless belt 10 is bonded to the endless belt main body 11 with a meander-preventing bead 12 and left at room temperature for 72 hours or more until the adhesive force is stabilized, and further for 3 hours in an environment of 23 ° C. and 50% relative humidity. The circumference of the endless belt 10 after standing is measured with a circumference measuring device to obtain a circumference B (mm) before wet heat aging.

  Thereafter, the endless belt 10 is wound around a circumference measuring device and held between the rolls with a tension of 6 kg, and after being put in an environment of a temperature of 70 ° C. and a relative humidity of 90% for 72 hours, the temperature of 23 ° C. And left in an environment of 50% relative humidity for 72 hours. The circumferential length of the endless belt 10 after the wet heat aging is C (mm).

  On the other hand, the meandering prevention bead 12 is peeled from the endless belt body 11 by hand so as not to generate a tensile stress, and then measured in the longitudinal direction. The dimension in the longitudinal direction of the meandering prevention bead 12 after the wet heat aging is defined as D (mm).

  Here, the dimensional change rate of the endless belt 10 in the circumferential direction is X1 (%), and X1 = 100 × (C−B) / B. Further, the dimensional change rate of the meandering prevention bead 12 in the longitudinal direction is set to X2 (%), and X2 = 100 × (DA) / A. At this time, the absolute value of X1-X2 is expressed as a difference in dimensional change rate.

Next, the present invention will be described in more detail with reference to examples and comparative examples. The endless belt 10 according to the present invention is not limited to the following implementation.
[Example 1]

  The endless belt body 11 was prepared by the above-described method, and was prepared by throwing it into an oven at a temperature of 220 ° C. for 90 minutes.

Next, in the meandering prevention bead 12, polyurethane was used as the elastic material layer 16 and PET film was used as the rigid material layer 17. Then, a meander-preventing bead was manufactured by removing a die from the original bead obtained by laminating the elastic material layer 16 to the rigid material layer 17 having a winding tension of 1.654 N / mm ² .

  The endless belt 10 of Example 1 was obtained by bonding the rigid material layer 17 side of the meandering prevention bead 12 to the inner peripheral surface of the endless belt body 11.

The winding tension at this time is 1.654 N / mm ² for the following reason. That is, when laminating the elastic material layer 16 to the rigid material layer 17, the rigid material layer 17 is cooled after being bonded while applying a predetermined tension. It will be commercialized as it is stored. Therefore, it is preferable that the winding tension is small. However, if the winding tension is too small, the rigid material layer 17 bends on the inner peripheral surface of the endless belt body 11 and does not finish cleanly. .
[Example 2]

  The endless belt body 11 was prepared by the above-described method, and was prepared by throwing it into an oven at a temperature of 220 ° C. for 90 minutes.

Next, chloroprene rubber was used as the elastic material layer 16 and PET film was used as the rigid material layer 17 in the meandering prevention bead 12. Then, a meander-preventing bead was produced by removing a die from the original bead obtained by laminating the elastic material layer 16 to the rigid material layer 17 having a winding tension of 1.654 N / mm ² .

The endless belt 10 of Example 2 was obtained by bonding the rigid material layer 17 side of the meandering prevention bead 12 to the inner peripheral surface of the endless belt body 11.
[Example 3]

  The endless belt body 11 was prepared by the above-described method, and was prepared by throwing it into an oven at a temperature of 220 ° C. for 90 minutes.

Next, chloroprene rubber was used as the elastic material layer 16 and PET film was used as the rigid material layer 17 in the meandering prevention bead 12. Then, a meander-preventing bead was produced by removing a die from the original bead obtained by laminating the elastic material layer 16 to the rigid material layer 17 having a winding tension of 7.5 N / mm ² .

The endless belt 10 of Example 3 was obtained by bonding the rigid material layer 17 side of the meandering prevention bead 12 to the inner peripheral surface of the endless belt body 11.
[Example 4]

  The endless belt body 11 was prepared by the above-described method, and was prepared by throwing it into an oven at a temperature of 220 ° C. for 90 minutes.

Next, in the meandering prevention bead 12, polyurethane was used as the elastic material layer 16 and PET film was used as the rigid material layer 17. Then, a meander-preventing bead was produced by removing a die from the original bead obtained by laminating the elastic material layer 16 to the rigid material layer 17 having a winding tension of 7.5 N / mm ² .

The endless belt 10 of Example 4 was obtained by bonding the rigid material layer 17 side of the meandering prevention bead 12 to the inner peripheral surface of the endless belt body 11.
[Example 5]

  The endless belt main body 11 was prepared by the above-described method, and was produced by putting it in an oven at a temperature of 180 ° C. for 90 minutes.

Next, chloroprene was used as the elastic material layer 16 and PET film was used as the rigid material layer 17 in the meandering prevention bead 12. Then, a meander-preventing bead was manufactured by removing a die from the original bead obtained by laminating the elastic material layer 16 to the rigid material layer 17 having a winding tension of 12 N / mm ² .

The endless belt 10 of Example 5 was obtained by bonding the rigid material layer 17 side of the meandering prevention bead 12 to the inner peripheral surface of the endless belt body 11.
[Example 6]

  The endless belt main body 11 was prepared by the above-described method, and was produced by putting it in an oven at a temperature of 180 ° C. for 90 minutes.

Next, chloroprene was used as the elastic material layer 16 in the meandering prevention bead 12, but the rigid material layer 17 was not used. And the winding tension | tensile_strength of the bead original fabric at the time of shaping | molding was 12 N / mm < ² >, the die was cut off, and the meander prevention bead was produced.

The paper on the back surface of the meandering prevention bead 12 was peeled off and adhered to the inner peripheral surface of the endless belt body 11 to obtain an endless belt 10 of Example 6.
[Example 7]

  The endless belt body 11 was prepared by the above-described method, and was produced by throwing it into an oven at a temperature of 200 ° C. for 90 minutes.

Next, in the meandering prevention bead 12, polyurethane was used as the elastic material layer 16, and the intermediate material layer 17 was not used. And the winding tension at the time of shaping | molding was 3.2 N / mm < ² >, the die was cut off, and the meandering prevention bead was produced.

The paper on the back surface of the meandering prevention bead 12 was peeled off and adhered to the inner peripheral surface of the endless belt body 11 to obtain an endless belt 10 of Example 7.
[Example 8]

  The endless belt body 11 was prepared by the above-described method, and was prepared by throwing it into an oven at a temperature of 220 ° C. for 90 minutes.

  Next, chloroprene rubber was used as the elastic material layer 16 and PET film was used as the intermediate material layer 17 in the meandering prevention bead 12. Then, when laminating the elastic material layer on the rigid material layer 17, the bead 12 for meandering prevention is produced by removing the die from the original bead with a draw rate of 3%, which is the ratio of the number of rotations between the rolls. did.

The endless belt 10 of Example 8 was obtained by bonding the rigid material layer 17 side of the meandering prevention bead 12 to the inner peripheral surface of the endless belt body 11.
[Comparative Example 1]

  The endless belt body 11 was prepared by the above-described method, and was produced by throwing it into an oven at a temperature of 200 ° C. for 90 minutes.

Next, in the meandering prevention bead 12, polyurethane was used as the elastic material layer 16, and PET film was used as the rigid material layer 17. And the winding tension | tensile_strength of the rigid material layer 17 was set to 12 N / mm < ² >, the die was cut | disconnected from the bead original fabric which laminated the elastic material layer 16, and the meander prevention bead was produced.

The endless belt 10 of Comparative Example 1 was obtained by bonding the rigid material layer 17 side of the meandering prevention bead 12 to the inner peripheral surface of the endless belt body 11.
[Test method]

  For each of Experimental Examples 1 to 8 and Comparative Example 1, the endless belt 10 is incorporated in the measurement unit 23 shown in FIG. 4 in order to confirm the adhesion state between the endless belt body 11 and the meandering prevention bead 12. In this state, the circumference of the endless belt 10 was measured with a three-dimensional shape measuring instrument (manufactured by Mitutoyo Corporation, model BH506).

  Then, the endless belt body 11 and the meander-preventing bead 12 are adhered to each other, and the endless belt 10 is stretched under a tension of 6 kg under a temperature of 70 ° C. and a relative humidity of 90%. Leave it for a while to age with heat and humidity.

  Thereafter, when the endless belt 10 was cooled to room temperature, the circumference of the endless belt 10 was measured by a three-dimensional shape measuring instrument (model BH506, manufactured by Mitutoyo Corporation). In the meandering prevention bead, the longitudinal dimension before joining to the endless belt body 11 and the longitudinal dimension peeled off from the endless belt body 11 after the test are measured to calculate the dimensional change rate before and after wet heat aging. did. Further, after the wet heat aging, before the meandering prevention bead 12 was peeled from the endless belt body 11, the height at which the meandering prevention bead 12 was lifted from the endless belt body 11 was measured by calipers or visually observed. The results are shown in Tables 1 and 2.

  That is, in Example 1, the dimensional change rate in the circumferential direction of the endless belt 10 is + 0.05%, the dimensional change rate in the longitudinal direction of the meandering prevention bead 12 is -0.12%, and the dimensional change rate. The absolute value of the difference was + 0.17%, but the meandering prevention bead 12 was not lifted. In this case, it was recognized that the absolute value of the difference in dimensional change rate was 0.5% or less.

  In Example 2, the dimensional change rate in the circumferential direction of the endless belt 10 is + 0.05%, the dimensional change rate in the longitudinal direction of the meandering prevention bead 12 is -0.13%, and the difference in dimensional change rate is The absolute value of was 0.18%, but the meandering prevention bead 12 was not lifted. In this case, it was recognized that the absolute value of the difference in dimensional change rate was 0.5% or less.

  In Example 3, the dimensional change rate in the circumferential direction of the endless belt 10 is + 0.12%, the dimensional change rate in the longitudinal direction of the meandering prevention bead 12 is + 0.58%, and the difference in dimensional change rate is Although the absolute value was + 0.46%, the meandering prevention bead 12 was not lifted. In this case, it was recognized that the absolute value of the difference in dimensional change rate was 0.5% or less.

  In Example 4, the dimensional change rate in the circumferential direction of the endless belt 10 is + 0.12%, the dimensional change rate in the longitudinal direction of the meandering prevention bead 12 is + 0.58%, and the difference in dimensional change rate is Although the absolute value was + 0.46%, the meandering prevention bead 12 was not lifted. In this case, it was recognized that the absolute value of the difference in dimensional change rate was 0.5% or less. The results obtained in Examples 1 to 4 are shown in Table 1.

  In Example 5, the dimensional change rate in the circumferential direction of the endless belt 10 is + 0.22%, the dimensional change rate in the longitudinal direction of the meandering prevention bead 12 is + 0.69%, and the difference in dimensional change rate is Although the absolute value was + 0.47%, the meandering prevention bead 12 was not lifted. In this case, it was recognized that the absolute value of the difference in dimensional change rate was 0.5% or less.

  In Example 6, the dimensional change rate in the circumferential direction of the endless belt 10 is + 0.22%, the dimensional change rate in the longitudinal direction of the meandering prevention bead 12 is + 0.69%, and the difference in dimensional change rate is Although the absolute value was + 0.47%, the meandering prevention bead 12 was not lifted. In this case, it was recognized that the absolute value of the difference in dimensional change rate was 0.5% or less.

  In Example 7, the dimensional change rate in the circumferential direction of the endless belt 10 is + 0.12%, the dimensional change rate in the longitudinal direction of the meandering prevention bead 12 is -0.21%, and the difference in dimensional change rate is The absolute value of was 0.44%, but the meandering prevention bead 12 was not lifted. In this case, it was recognized that the absolute value of the difference in dimensional change rate was 0.5% or less.

  In Example 8, the dimensional change rate in the circumferential direction of the endless belt 10 is + 0.05%, the dimensional change rate in the longitudinal direction of the meandering prevention bead 12 is -0.15%, and the difference in dimensional change rate is The absolute value of was 0.20%, but the meandering prevention bead 12 was not lifted up. In this case, it was recognized that the absolute value of the difference in dimensional change rate was 0.5% or less.

  In Comparative Example 1, the dimensional change rate in the circumferential direction of the endless belt 10 is + 0.12%, the dimensional change rate in the longitudinal direction of the meandering prevention bead 12 is -0.72%, and the difference in dimensional change rate is The absolute value of was 0.88%, but the lifting of the meandering prevention bead 12 was visually confirmed. In this case, it was recognized that the absolute value of the dimensional change rate difference was greater than 0.5%. Table 2 shows the results obtained in Examples 5 to 8 and Comparative Example 1.

  Further, for the meander-preventing beads of Examples 1 to 8 and Comparative Example 1 described above, waving, wear, handling, unit rotation stability, and durability were evaluated, and comprehensive judgment was performed.

  The floating state of the meander-preventing bead 12 is very preferable (蛇) when the meander-preventing bead 12 is not peeled off from the endless belt body 11 by visual observation, and the meander-preventing bead 12 is removed from the endless belt body 11. Although it has peeled, it is preferable (◯) when the degree is less than 30% of the width of the endless belt 11. The meander-preventing bead 12 is peeled off from the endless belt body 11 and the degree thereof is 30% or more of the width of the endless belt 11, but it is preferable for the case where it is not completely peeled off (Δ ), And when the meandering prevention bead 12 is peeled off in the direction of the rotation axis of the endless belt body 11, it is determined as defective (×).

  The waviness of the meander-preventing bead 12 is judged by visual observation, and it is very preferable (◎) when the end of the meander-preventing bead 12 is not corrugated on the inner peripheral surface of the endless belt body 11 after the test. If it sees closely, it will be preferable when it is slightly wavy. Further, the meandering prevention bead 12 is gently undulated, but it is preferable (Δ) when there is no problem in use, and the meandering bead on the inner peripheral surface of the endless belt body 11 is large. When the end portion of 12 is too wavy and cannot be used, it is judged as defective (x).

  Abrasion is an evaluation of how much the edge portion of the elastic material layer 16 that contacts the fitting groove 15 is scraped by continuing to operate the endless belt 10. Abrasion is very favorable (◎) when there is a part that is slightly scraped but is almost the same as when it is not shaved by visual inspection, and is favorable (○) when it can be judged that there is no problem in use though it is scraped. . Also, it is preferable (Δ) when the sharpness is noticeable but it can be determined that it can be used at last, and it is determined as poor (×) when the sharpness is severe and the product is not useful.

  With regard to handling properties, when the meander-preventing bead 12 is bonded to the endless belt main body 11, if the rigid material layer 17 is not provided, the meander-preventing bead 12 is not stiff and is too flexible and difficult to handle. . This is an evaluation of the degree of difficulty of handling the meandering prevention bead 12. The handling property is very preferable when the stiffness of the meander-preventing bead 12 is firm and easy to handle (◎), and is preferable when it can be used although it is soft and easy to meander with no stiffness. To do. Moreover, when handling property is bad and it cannot use, it is set as a defect (x).

  When the endless belt 10 is set on the measuring unit 23 and the unit rotational stability moves away from the center of the standard value due to the dimensional change of the endless belt 10, the torque applied to the rollers 21 and 22 becomes weak or excessive. This is an evaluation that the rollers 21, 22 and the endless belt 10 are difficult to rotate. The unit rotation stability of the meander-preventing bead 12 is very favorable when the optimum torque is applied with almost no dimensional change of the endless belt 10 (最適). It is preferable (◯) when there is no problem. Further, when the endless belt 10 to which the meandering prevention bead 12 is bonded is left in an environment of 70 ° C. and 90% relative humidity for 72 hours and rotated by an endurance test as shown in FIG. 5, the endless belt 10 contracts. If the endless belt 10 does not rotate smoothly due to excessive torque applied to the rollers 21 and 22 or excessive friction of the endless belt 10 when the endless belt 10 expands. Is not preferable (Δ).

  In the belt endurance tester shown in FIG. 5, the endurance belt 10 is hung on the rollers 21 and 22 and the roller 21 is driven by the motor unit 51 attached to the shaft of the roller 21. Measurement is performed by continuously rotating the endless belt 10 and testing. The frequency of confirming the state of the endless belt 10 is confirmed every 1000 rotations until the endless belt 10 rotates 10,000 times, and after the endless belt 10 rotates 10,000 times, the state is confirmed every 10,000 rotations, and the meandering prevention bead When the abnormality was confirmed by cracking or breaking 12, the number of rotations was determined by the number of rotations at the time of confirmation before the number of occurrences of abnormality.

  Endless belts used in general electrophotographic apparatuses are required to have a durability of 100,000 (hereinafter, simply referred to as “100K”) rotation. Therefore, in the endless belt 10, the endless belt 10 showing durability of 200 K rotations or more is very preferable (）), and the endless belt 10 showing durability of 100 K rotations or more and less than 200 K rotations is very preferable (◯). It was. Further, the endless belt 10 that showed only durability of less than 100K rotation was regarded as defective (x).

  In the overall judgment, (◎) was very preferable, (◯) was preferable, (Δ) was preferable, and (X) was poor. The results are shown in Tables 1 and 2.

  From the above results, when wet heat aging is performed with the endless belt body 11 bonded to the meandering prevention bead 12, the dimensional change rate in the circumferential direction of the endless belt 10 that occurs before and after wet heat aging, and the meander that occurs before and after wet heat aging. If the absolute value of the difference from the dimensional change rate in the longitudinal direction of the prevention bead 12 is 0.5% or less, the meandering bead 12 adhered to the endless belt body 11 is removed from the endless belt body 11. It was confirmed that it did not rise.

  At this time, the meander-preventing bead 12 sets the endless belt 10 on the rollers 13 and 14 when the dimensional change rate in the longitudinal direction occurring before and after wet heat aging is −0.5 to + 0.5%. It has been confirmed that the torque applied to the rollers 13 and 14 when operated can be provided with an electrophotographic apparatus that can be operated stably and stably without being too high or too low.

  Even when the meander-preventing bead 12 is made of only the elastic material layer 16, the rate of dimensional change in the circumferential direction of the endless belt 10 that occurs before and after wet heat aging and the longitudinal direction of the meander-preventing bead 12 that occurs before and after wet heat aging. If the absolute value of the difference from the dimensional change rate is 0.5% or less of the endless belt 10, it is confirmed that the meandering prevention bead 12 adhered to the endless belt body 11 does not float from the endless belt body 11. I was able to drive the device.

  However, when the meander-preventing bead 12 without the rigid material layer is bonded to the endless belt body 11, the elastic material layer 16 has a high flexibility, so that the shape-retaining property when the meander-preventing bead 12 is adhered is poor, It was not easy to adhere to the endless belt body 11.

It is a lineblock diagram showing an endless belt concerning an embodiment of this invention. It is a block diagram which shows the state which wound the endless belt which concerns on the same embodiment on the roller. It is sectional drawing which shows the adhesion state of the endless belt which concerns on the same embodiment, and the meandering prevention bead. It is the schematic which shows the circumference measuring apparatus of the endless belt which concerns on the same embodiment. It is the schematic which shows the endurance tester of the endless belt which concerns on the same embodiment. It is a block diagram which shows the conventional endless belt.

Explanation of symbols

10 Endless belt
11 Endless belt body
12 Meander prevention beads
16 Elastomer material layer
17 Film material layer
18 Acrylic double-sided pressure-sensitive adhesive

Claims (5)

Endless belt for electrophotography in which at least one substantially linear meandering bead having a uniform cross section along one side or both ends of an inner peripheral surface of a flexible endless belt body is bonded. Because
The meandering prevention bead is composed of two layers in which an elastic material layer and a rigid material layer are bonded to each other, and the rigid material layer of the meandering prevention bead is adhered to an inner peripheral surface of the endless belt body. An endless belt for electrophotography.   The endless belt for electrophotography according to claim 1, wherein the elastic material layer is made of polyurethane, and the rigid material layer is made of polyethylene terephthalate.   When the endless belt body and the meander-preventing bead are bonded to each other in the circumferential direction of the endless belt that occurs before and after the wet heat aging when wet heat aging is performed for 72 hours in an environment of a temperature of 70 ° C. and a relative humidity of 90%. An endless belt for electrophotography, wherein an absolute value of a difference between a dimensional change rate and a dimensional change rate in a longitudinal direction of the meandering prevention bead generated before and after the wet heat aging is 0.5% or less.   4. The electrophotographic endless belt according to claim 3, wherein the meandering prevention bead has a dimensional change rate in a longitudinal direction before and after the wet heat aging of −0.5% to + 0.5%. 5. The meander-preventing bead is composed of two layers in which an elastic material layer and a rigid material layer are bonded to each other, and the elastic material layer is laminated and bonded to the rigid material layer. 5. The electrophotographic endless belt according to claim 3, wherein a tensile stress in the longitudinal stretching direction of the rigid material layer at a temperature of 80 ° C. is 1.0 to 8.5 N / mm ² .

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