JP2012068558A - Endless belt and endless belt unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endless belt capable of running without bending a cleaning blade brought into press-contact with the external surface; and an endless belt unit preventing a bend of the cleaning blade brought into press-contact with the endless belt for a long period of time.SOLUTION: An endless belt 1 is characterized of containing a polyamide-imide resin and a silicone surfactant and comprising a resin layer with a surface with which a cleaning blade is brought into press-contact. An endless belt unit is equipped with the endless belt 1 wound around a plurality of rotary bodies and running on an endless track and with a cleaning blade brought into press-contact with the external surface of the endless belt 1.

Description

  The present invention relates to an endless belt and an endless belt unit. More specifically, the endless belt that can run without bending the cleaning blade that presses against the outer surface and the cleaning blade that presses against the outer surface of the endless belt are folded over a long period of time. It relates to an endless belt unit that is difficult to bend.

  Various image forming apparatuses using an electrophotographic system are employed in printers such as laser printers and video printers, copiers, facsimiles, and multi-function machines thereof. Such an image forming apparatus is equipped with various endless belts. Examples of such an endless belt include a transfer conveyance belt that conveys a recording medium onto which a developer is transferred during conveyance, and conveys the intermediate transfer belt in a secondary transfer type image forming apparatus. Examples thereof include a fixing belt wound around a roller.

  These endless belts are usually configured to perform their intended functions each time they travel on an endless track, and repeatedly perform their intended functions by traveling repeatedly on the endless track. Since the endless belt contacts or may come into contact with the developer during traveling, the developer may adhere to the outer surface of the endless belt and become contaminated. The transfer conveyance belt will be specifically described as an example. The recording material conveyed by the transfer conveyance belt is transferred with the developer from, for example, an image carrier that carries the developer image, for example, a photoconductor, during the conveyance. At this time, the developer carried on the image carrier or the developer transferred to the recording medium may be scattered and a part of the developer may adhere to the outer surface of the transfer conveyance belt. On the other hand, if the rotation of the image carrier and the running of the transfer conveyance belt are not accurately synchronized, the developer carried on the image carrier or the like is not transferred to the recording body, and the transfer conveyance belt May be transferred to the outer surface.

  Therefore, the image forming apparatus usually includes a cleaning unit that removes the developer attached to the outer surface of the endless belt. This cleaning means has, for example, a cleaning blade that presses against the outer surface of the endless belt, and scrapes off the developer adhering to the outer surface of the endless belt with this cleaning blade until the endless belt makes one revolution. It is configured.

  An example of the endless belt cleaning means is shown in FIG. As shown in FIG. 4A, the cleaning blade 101 that presses against the endless belt 102 and removes the developer attached to the endless belt 102 is usually the outer surface of the endless belt 102, The endless belt 102 does not perform a function on the outer surface 104 (hereinafter referred to as a non-functional outer surface) when the endless belt 102 is in a track in which the endless belt 102 does not perform a predetermined function in the endless track, that is, in the return path. In the middle of the track (return track), one end or one end edge is upstream of the traveling direction of the endless belt 102 (the direction indicated by the arrow A in FIG. 4A), and the other end or other end is In a state where the endless belt 1 is disposed on the downstream side with respect to the traveling direction, the endless belt 1 is disposed so as to come into pressure contact with the endless belt 102 at a predetermined angle and a predetermined pressing load.

  For one purpose of “preventing abrasion of the cleaning blade” in such a cleaning means, Patent Document 1 discloses that “a transfer belt to which a toner image is transferred from an image carrier in an image forming apparatus, A transfer belt comprising a chain silicone in a matrix resin, a silicone content in the matrix resin of 0.5 to 10% by weight, and an average molecular weight of the chain silicone of 100,000 or more ” Are listed.

  However, since the cleaning blade 101 is in pressure contact with the endless belt 102, when the endless belt 102 travels, the cleaning blade 101 is brought into contact with the endless belt 102 as shown in FIG. 4B due to friction with the endless belt 102. May be bent or warped in the traveling direction (in the direction of arrow A in FIG. 4), and may not function sufficiently as the cleaning blade 101. Such bending of the cleaning blade 101 may occur even if the cleaning blade 101 can be prevented from being worn, and is a problem different from the wear of the cleaning blade 101. In particular, the cleaning blade 101 is bent at one end portion of the cleaning blade 101 that presses the endless belt 102 when the endless belt 102 travels in an image forming apparatus in which the printing speed, that is, the traveling speed of the endless belt 102 is increased. Since an excessive load is applied to the edge of one end, it is more likely to occur.

Japanese Patent No. 3925508

  An object of the present invention is to provide an endless belt that can run without bending a cleaning blade that is pressed against an outer surface.

  Another object of the present invention is to provide an endless belt unit in which a cleaning blade that is in pressure contact with the surface of an endless belt is not easily bent over a long period of time.

As means for solving the problems,
Claim 1 is an endless belt characterized by comprising a polyamideimide resin and a silicone surfactant, and comprising a resin layer on the outer surface of which a cleaning blade is pressed.
In Claim 2, the silicone surfactant is contained in the resin layer at a ratio of 0.1 to 2 parts by mass with respect to 100 parts by mass of the polyamideimide resin. Endless belt,
Claim 3 is an endless comprising the endless belt according to claim 1, which is wound around a plurality of rotating bodies and travels on an endless track, and a cleaning blade pressed against the outer surface of the endless belt. It is a belt unit.

  In the endless belt according to the present invention, the resin layer with which the cleaning blade is in pressure contact with the outer surface contains the polyamideimide resin and the silicone surfactant. Therefore, an excessive load on the cleaning blade and an excessive amount due to the running of the endless belt. It can pass smoothly over the cleaning blade without applying vibration. As a result, the endless belt according to the present invention smoothly runs on the cleaning blade for a long period of time even if the running speed is high, and the initial function is impaired as shown in FIG. 4B, for example. The cleaning blade is not bent so much as much as possible. Therefore, according to the present invention, it is possible to provide an endless belt that can travel without bending the cleaning blade that presses against the outer surface.

  Further, according to the present invention, since the endless belt unit according to the present invention includes the endless belt according to the present invention and the cleaning blade, the cleaning blade that presses the surface of the endless belt is not easily bent over a long period of time. A belt unit can be provided.

FIG. 1 is a schematic perspective view showing an endless belt which is an embodiment of an endless belt according to the present invention. FIG. 2 is a schematic view showing a tandem color image forming apparatus which is an example of an image forming apparatus provided with an endless belt unit according to the present invention. FIG. 3 is a view showing the cleaning blade in the endless belt unit according to the present invention, FIG. 3A is a front view showing the cleaning blade in the endless belt unit according to the present invention, and FIG. It is a side view which shows the cleaning blade in the endless belt unit which concerns on invention. FIG. 4 is an explanatory view for explaining the pressure contact state between the endless belt and the cleaning blade in the endless belt unit, and FIG. 4 (a) is a view for explaining the initial pressure contact state between the endless belt and the cleaning blade in the endless belt unit. FIG. 4B is an explanatory diagram illustrating a state where the cleaning blade is turned over in the endless belt unit. FIG. 5 is a schematic front view showing an example of a slip angle measuring device for measuring the slip angle of the endless belt. FIG. 6 is a schematic top view showing an example of a torque measuring device that measures the torque of the endless belt and the amount of torque fluctuation.

  The endless belt according to the present invention includes a resin layer on which the cleaning blade is pressed against the outer surface when the endless belt is mounted on an image forming apparatus or the like to constitute an endless belt unit. It may be made into the multilayer structure which comprises a resin layer as an outermost layer. In the endless belt according to the present invention, the resin layer contains a polyamideimide resin and a silicone surfactant. The polyamide-imide resin and the silicone surfactant will be described later. As described above, the endless belt according to the present invention having such characteristics can be rolled up on the cleaning blade pressed against the outer surface without bending the cleaning blade, in other words, without warping. It can run smoothly.

  An endless belt which is an example of an endless belt according to the present invention will be described with reference to the drawings. As shown in FIG. 1, the endless belt 1 has a single-layer structure including only a resin layer formed in a ring shape by a polyamideimide resin composition described later. Therefore, in this endless belt 1, the endless belt 1 and the resin layer are synonymous. The thickness of the endless belt 1 is not particularly limited, but usually, for example, preferably 0.03 to 1 mm, more preferably 0.05 to 0.2 mm, and about 0.07 to 0.14 mm. Is particularly preferred. If the thickness of the endless belt 1 is less than 0.03 mm, the mechanical strength of the endless belt 1 may decrease. On the other hand, if it exceeds 1 mm, the flexibility of the endless belt 1 decreases and the durability is poor. There is. The width and inner peripheral diameter of the endless belt 1 are set as appropriate. For example, the width of the endless belt 1 is 200 to 350 mm, and the circumferential length is 200 to 2,500 mm.

  The endless belt 1 contains a polyamideimide resin described later and a silicone surfactant described later. In other words, the endless belt 1 is a polyamide-imide resin molded body containing a silicone surfactant. When the endless belt 1 contains a polyamideimide resin and a silicone surfactant, the mechanical characteristics of the endless belt 1 itself are excellent as described later, and the slip angle of the outer surface can be greatly reduced. Therefore, when the endless belt 1 contains a silicone surfactant, the endless belt 1 can smoothly run on the cleaning blade without bending the cleaning blade.

  The content of the silicone surfactant contained in the endless belt 1 is preferably 0.1 to 2 parts by mass with respect to 100 parts by mass of the polyamideimide resin constituting the endless belt 1, and 0.1 to 1 It is particularly preferable that the ratio is part by mass. When the silicone surfactant is contained in the endless belt 1 within the above range, the endless belt 1 can run on the cleaning blade more smoothly. The content of the silicone surfactant contained in the endless belt 1 can be measured by elemental analysis of the endless belt 1 with a photoelectron spectrometer (ESCA). Usually, the content of the silicone surfactant in the endless belt 1 substantially matches the content of the silicone surfactant with respect to 100 parts by mass of the resin contained in the polyamideimide resin composition forming the endless belt 1. The silicone surfactant contained in the endless belt 1 may be one kind or two or more kinds.

  The endless belt 1 may contain various additives, which will be described later, in addition to the polyamideimide resin and the silicone surfactant, but is substantially free of fluorine compounds. Here, “substantially free” means that the fluorine compound is not actively contained, and includes, for example, the case of containing a fluorine compound as an inevitable component such as an impurity. Absent.

  The endless belt 1 preferably has a sliding angle of 10 to 20 °, and particularly preferably 12 to 18 ° in the following measurement method. The slip angle in the following measurement method is one index for evaluating that the endless belt 1 can smoothly run on the outer surface without bending the cleaning blade, and is based on the static friction coefficient, the dynamic friction coefficient, the contact angle, and the like. When the endless belt 1 is found to be effective and the slip angle of the endless belt 1 is within the above range, the traveling endless belt 1 smoothly travels on the cleaning blade without applying excessive load and excessive vibration to the cleaning blade. The bending of the cleaning blade can be substantially prevented. In other words, when the slip angle of the endless belt 1 is within the above range, the endless belt 1 can maintain the initial pressure contact state with the cleaning blade for a long period of time.

  This slip angle is measured using, for example, a slip angle measuring device 60 shown in FIG. The slip angle measuring device 60 only needs to include a stage 61 that is pivotally supported at one end and rotatable about the one end, and a measuring device 62 that measures the amount of rotation of the stage 61, that is, the rotation angle. A fixing portion 63 for fixing the rotated stage 61 is provided. In this slip angle measuring device 60, the stage 61 is a plate-like member having a flat surface, and the measuring instrument 62 is a protractor. As shown in FIG. 5, the fixing portion 63 has a first support rod 64 whose one end is connected to the base of the slip angle measuring device 60, and one end that is rotatable to the other end of the first support rod 64. And a second support rod 65 having the other end connected to the lower portion of the stage 61, and the pivot between the first support rod 64 and the second support rod 65 according to the amount of rotation of the stage 61. A support part rotates and the stage 61 is supported and fixed from the downward direction. The slip angle measuring device 60 shown in FIG. 5 shows an initial state in which the stage 61 is substantially horizontal.

  The slip angle of the endless belt 1 is measured as follows. A test piece 66 cut out from the endless belt 1 in a longitudinal direction of 30 mm × a circumferential direction of 150 mm in an environment of 24 ° C. and a relative humidity of 50% (thickness does not matter. Ten-point average roughness Rz is adjusted to 0.18 μm). The adhesive tape on the stage 61 of the slip angle measuring device 60, for example, the trade name “Kapton Film Adhesive Tape” (manufactured by Teraoka Seisakusho Co., Ltd.), the longitudinal direction of the test piece 66 is from the longitudinal direction of the stage 61, that is, one end thereof Affix and fix so that it is substantially parallel to the direction along the free end. Next, a contact member 67 having a length of 40 mm, a width of 100 mm, and a thickness of 1.5 mm (mass: about 4.0 g) is placed on the test piece 66 so that the vertical direction is substantially parallel to the longitudinal direction of the test piece 66. , Place. The contact member 67 is made of a melamine resin, and the surface in contact with the test piece 66 is adjusted to have a ten-point average roughness Rz of 0.94 μm, a static friction coefficient of 0.465, and a dynamic friction coefficient of 0.225. . Next, the stage 61 is gradually rotated around one end so that the angle between the surface of the stage 61 and the horizontal plane gradually increases, and the angle when the contact member 67 starts to slide on the test piece 66 is determined. Measure with the measuring device 62. This measurement is performed a plurality of times, for example, three times, and the arithmetic average value of the measured values is set as the slip angle of the endless belt 1. The ten-point average roughness Rz (μm) of the test piece 66 and the contact member 67 is in accordance with JIS B 0601-1984, and is a surface roughness meter (trade name “590A”, stock) equipped with a measurement probe having a tip radius of 2 μm. The test piece 66 or the contact member 67 is set on the outer surface of the test piece 66 or the contact member 67 with a measurement length of 2.4 mm, a cutoff wavelength of 0.8 mm, and a cutoff type Gaussian. The roughness of at least 3 points is measured along the direction, and the arithmetic average value of these points is obtained.

  The endless belt 1 preferably has a torque of 0.01 to 0.20 N · m, and particularly preferably 0.03 to 0.15 N · m in the following measurement method. The torque in the following measurement method is one index for evaluating that the endless belt 1 can smoothly run on the cleaning blade without bending the cleaning blade pressed against the outer surface, and is based on a static friction coefficient, a dynamic friction coefficient, a contact angle, and the like. When it is found that the torque of the endless belt 1 is within the above range, the running endless belt 1 smoothly runs on the cleaning blade without giving an excessive load and excessive vibration to the cleaning blade, It is possible to substantially prevent the cleaning blade from being bent.

  The endless belt 1 preferably has a torque fluctuation amount of 0.01 to 0.05 N · m, particularly 0.01 to 0.03 N · m, in addition to the torque in the above range. preferable. The torque fluctuation amount in the following measurement method is one index for evaluating that the endless belt 1 can smoothly run on the cleaning blade without bending the cleaning blade pressed against the outer surface thereof, such as a static friction coefficient, a dynamic friction coefficient, and a contact angle. If the torque fluctuation amount of the endless belt 1 is within the above range, the traveling endless belt 1 can further travel on the cleaning blade without applying an excessive load and excessive vibration to the cleaning blade. It is possible to travel smoothly and substantially prevent the cleaning blade from being bent.

  The torque and torque fluctuation amount of the endless belt 1 are measured using, for example, a torque measuring device 70 shown in FIG. The torque measuring device 70 includes a tension part 71 that stretches the endless belt 1 (shown by a broken line in FIG. 6), a drive part 72 that rotates the tension part 71, and a period during which the tension part 71 is rotated. And a measuring unit 73 for measuring torque. The tension portion 71 includes a pair of rollers 71a and 71b that are rotatably supported at both ends of the shaft body by the support body 71c and arranged in parallel so as to be close to each other or can be separated from each other. 1 is stretched. The roller 71b rotates with the driving unit 72 connected to its shaft body, and the roller 71a rotates following the roller 71a via the endless belt 1 stretched around the roller 71b. The driving unit 72 usually employs a motor, and rotates the stretching unit 71 at a predetermined speed, for example, 17.8 cm / s. The measurement unit 73 is a device that is connected to the drive unit 72 and measures the rotational torque over time while the drive unit 72 is rotationally driven, and specifically includes a control circuit. In the torque measuring device 70, a mounting portion 74 (shown by a broken line in FIG. 6) on which a cleaning belt is mounted so as to be in pressure contact with the endless belt 1 stretched around the rollers 71a and 71b is provided on the axis of the rollers 71a and 71b. It is provided so that it may become parallel.

  The torque and torque fluctuation amount of the endless belt 1 are measured as follows. First, as shown in FIG. 6, the endless belt 1 is stretched around rollers 71a and 71b of the torque measuring device 70 with a predetermined tension. Next, the driving unit 72 and the measuring unit 73 are activated, and the stretching unit 71 is rotated at a predetermined speed by the driving unit 72 while the rotational torque of the driving unit 72 is measured by the measuring unit 73. The rotational torque of the drive unit 72 is measured and recorded with the start of the rotation of the stretching unit 71. At this time, the rotational torque is measured usually every 2 to 40 seconds after the rotational speed of the endless belt 1 reaches a predetermined speed, for example, every 0.1 second. Of the rotational torque measured in this way, the maximum value after the rotational speed of the endless belt 1 reaches a predetermined speed (from 60 seconds) is defined as the torque of the endless belt 1. On the other hand, a plurality of differences between the maximum torque and the minimum torque of the drive unit 72 when the endless belt 1 travels for 20 seconds after the rotational speed of the endless belt 1 reaches a predetermined speed are obtained as a torque fluctuation amount of the drive unit 72, The arithmetic average value of the torque fluctuation amount is defined as the torque fluctuation amount of the endless belt 1.

  The endless belt 1 preferably has a static friction coefficient in the range of 0.3 to 0.8 in the following measurement method, particularly preferably in the range of 0.4 to 0.8. The dynamic friction coefficient is preferably in the range of 0.2 to 0.7, and particularly preferably in the range of 0.3 to 0.7. When at least one of the static friction coefficient and the dynamic friction coefficient of the endless belt 1 is within the above range, the cleaning blade can run more smoothly.

  The static friction coefficient and the dynamic friction coefficient of the endless belt 1 can be measured as follows using a test sheet obtained by cutting the endless belt 1 into a circumferential length of 200 mm and a width direction of 100 mm. That is, when the test sheet is set on a surface property measuring instrument (trade name: 14FW, manufactured by Shinto Kagaku Co., Ltd.) and the cleaning blade is assumed not to be set, as specifically shown in FIG. One end edge of the tip of the cleaning blade 51 is pressed against the test sheet so that the contact angle θ between the surface of the test sheet and the cleaning blade 51 is 23 ° and the pressing load P is 1 MPa (at this time, the cleaning blade 51, one end edge is arranged on the upstream side with respect to the running direction of the test sheet, and the other end edge is arranged on the downstream side with respect to the running direction of the test sheet. In this state, the test sheet is caused to travel in one direction at a speed of 10 mm / second, and the resistance force applied to the cleaning blade 51 during traveling is measured. From the measured resistance force, the “resistance force / pressing load” is calculated. The static friction coefficient and the dynamic friction coefficient are obtained from the obtained numerical values. Here, the “pressing load” in the calculation formula when calculating the static friction coefficient is the “peak pressing load at the beginning of measurement” when the test sheet is run and the resistance force is measured, and the dynamic friction coefficient is calculated. The “pressing load” in the above calculation formula is “the average pressing load excluding the peak pressing load at the beginning of measurement, ie, when the test sheet is running” when the resistance value is measured by running the test sheet. Average pressing load ”. As shown in FIG. 3, the cleaning blade 51 has a thickness of 1 mm so that a urethane elastic body having a thickness of 2.0 mm, a width of 20 mm, and a length of 250 mm overlaps the surface of the width of 10 mm × the length direction of 250 mm. The urethane elastic body is bonded to an iron plate-shaped portion 55 having a width of 0.0 mm, a width of 20 mm, and a length of 250 mm. The urethane elastic body has a JIS A hardness of 70, a tensile permanent strain characteristic of 50%, and a wear amount in a measurement method described later. Is adjusted to 50 mg.

  The endless belt 1 preferably has a contact angle of n-dodecane of 10 to 40 °, and more preferably 15 to 40 °. When the contact angle of n-dodecane in the endless belt 1 is within the above range, the cleaning blade can run more smoothly. The contact angle of n-dodecane in the endless belt 1 can be measured using a contact angle meter (trade name “CA-DT type”, manufactured by Kyowa Interface Chemical Co., Ltd.). A sample obtained by cutting the endless belt 1 into a square of about 10 mm is set on a contact angle meter, and droplets of n-dodecane having a droplet diameter of 2 mm are adhered onto the sample. The measurement of the contact angle is obtained by reading the angle formed at the contact point between the sample and the droplet and the apex portion of the droplet with an angle scale built in the contact angle meter and converting it to double.

  The endless belt 1 preferably has any one of the static friction coefficient, the dynamic friction coefficient, and the contact angle of n-dodecane within the above range, and either the static friction coefficient or the dynamic friction coefficient and the contact angle of n-dodecane are It is even more preferable that the value is within the range, and it is particularly preferable that the coefficient of static friction, the coefficient of dynamic friction, and the contact angle of n-dodecane are within the above ranges.

The endless belt 1 preferably has a surface resistivity in the range of 1 × 10 ¹⁰ to 1 × 10 ¹⁵ Ω / □, and particularly preferably in the range of 1 × 10 ¹² to 1 × 10 ¹⁴ Ω / □. When the surface resistivity of the endless belt 1 is within the above range, a high quality image can be formed when the endless belt 1 is used in an image forming apparatus. This surface resistivity can be measured according to the surface resistivity measuring method described in JIS C2151 (1990).

The endless belt 1 preferably has a volume resistivity in the range of 1 × 10 ⁸ to 1 × 10 ¹³ Ω · cm, particularly preferably in the range of 1 × 10 ⁹ to 1 × 10 ¹² Ω · cm. When the volume resistivity of the endless belt 1 is within the above range, a high quality image can be formed when the endless belt 1 is used in an image forming apparatus. This volume resistivity can be measured according to JIS C2151 (1990).

  The endless belt 1 preferably has a Young's modulus in the range of 2,000 to 4,000 MPa, and particularly preferably in the range of 3,000 to 4,000 MPa. When the Young's modulus of the endless belt 1 is within the above range, even when a driving force is applied to the endless belt 1 when the endless belt 1 is mounted, a dimensional change such as elongation occurs in the endless belt 1, and color misregistration or the like occurs. It is possible to effectively prevent image failure. This Young's modulus can be measured according to JIS K7113 (1995).

  The endless belt 1 preferably has a flexibility test in the range of 50,000 to 200,000 times, particularly preferably in the range of 80,000 to 200,000 times. When the endurance test of the endless belt 1 is within the above range, even when the endless belt 1 is mounted on the image forming apparatus and travels, it is less likely to be fatigued by a bending operation when the support roller or the like passes. This softness test is basically the same as “ISO folding endurance number”, and can be measured according to JIS P8115 (2001) using a chuck tip R3.0 mm and a load of 1 kg.

  The endless belt 1 preferably has a tensile strength in the range of 100 to 180 MPa, and particularly preferably in the range of 120 to 160 MPa. When the tensile strength of the endless belt 1 is within the above range, the wearability is improved and the effect of high durability is obtained. This tensile strength can be measured according to JIS K7113 (1995).

  The endless belt 1 preferably has a tensile elongation in the range of 10 to 50%, particularly preferably in the range of 12 to 40%. When the tensile elongation of the endless belt 1 is within the above range, even if the end of the endless belt 1 is damaged, it is possible to prevent the endless belt 1 from being broken starting from the damaged portion. This tensile elongation can be measured according to JIS K7113 (1995).

  The endless belt 1 preferably has a tear strength in the range of 0.1 to 1.0 kg / mm, particularly preferably in the range of 0.2 to 0.8 kg / mm. When the tear strength of the endless belt 1 is within the above range, an effect that tearing can be suppressed from the notch portion is obtained. This tear strength can be measured according to JIS K7128-1 (1998).

  The endless belt 1 preferably has a flame resistance of UL94 5VA to UL94 V-2, and particularly preferably UL94 5VA to UL94 V-0. This flame retardancy can be measured according to UL standards.

  The endless belt 1 is manufactured by forming a resin layer in an annular shape from a polyamideimide resin composition described later. That is, the endless belt 1 is manufactured by curing a polyamideimide resin composition described later.

  The endless belt 1, that is, the resin layer is formed of a polyamideimide resin composition. This polyamideimide resin composition contains a polyamideimide resin or a constituent monomer thereof, a silicone surfactant, and various additives as required, and is substantially free of a fluorine compound. Here, “substantially free” means that the fluorine compound is not actively contained, and includes, for example, the case of containing a fluorine compound as an inevitable component such as an impurity. is not.

  Examples of the polyamideimide resin include a polyamideimide resin, a polyimide resin, and a polyamide resin. In particular, the aromatic polyamideimide resin is preferable in that it has excellent balance of mechanical properties such as strength, flexibility, dimensional stability, and heat resistance.

  The aromatic polyamideimide resin can be produced by a diisocyanate method in which a tricarboxylic acid anhydride and a diisocyanate compound are reacted, and the diisocyanate method is excellent in terms of availability of raw materials, reactivity and less by-products. . In addition to the aromatic polyamideimide resin produced by the diisocyanate method, an aromatic polyamideimide resin produced using a diamine compound instead of the diisocyanate compound can be used as long as the polycondensation reaction can be suitably advanced. preferable. The aromatic polyamideimide resin obtained by using the diamine compound has a high Young's modulus and is suitable as a resin contained in the polyamideimide resin composition forming the endless belt 1. Moreover, the aromatic polyamide-imide resin in which part of the tricarboxylic acid anhydride is replaced with tetracarboxylic dianhydride to increase the imide bond is excellent in moisture resistance. The aromatic polyamideimide resin can be easily synthesized by reacting in an appropriate solvent under normal pressure and at normal temperature or under heating.

  The tricarboxylic acid anhydride is preferably an aromatic tricarboxylic acid anhydride, such as trimellitic acid anhydride, 3,4,4′-diphenyl ether tricarboxylic acid anhydride, 3,4,4′-benzophenone tricarboxylic acid anhydride. 2,3,5-pyridinetricarboxylic acid anhydride, naphthalenetricarboxylic acid anhydride, and derivatives thereof. These acid anhydrides can be used alone or in combination of two or more.

  Examples of the tetracarboxylic dianhydride used in place of a part of the tricarboxylic acid anhydride include pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3, 3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2, 2'-bis (3,4-dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl) sulfonic dianhydride, perylene-3,4,9,10-tetracarboxylic dianhydride Bis (3,4-dicarboxyphenyl) ether dianhydride, ethylenetetracarboxylic dianhydride, and derivatives thereof. These tetracarboxylic dianhydrides may be used alone or in combination of two or more.

  Preferred examples of the diisocyanate compound include aromatic diisocyanate compounds. In addition, as the diisocyanate compound, an aliphatic diisocyanate compound and / or an alicyclic diisocyanate compound, or amines that are derivatives thereof can be used together with or in place of the aromatic diisocyanate compound.

  Examples of the aromatic diisocyanate compound include m-phenylene diisocyanate, p-phenylene diisocyanate, diphenylmethane-4,4′-diisocyanate, 4,4′-diisocyanate diphenyl ether, 4,4′-diisocyanate diphenyl sulfone, and 4,4′-diisocyanate. Biphenyl, 3,3′-dimethyl-4,4′-diisocyanate biphenyl, 2,4-toluene diisocyanate, xylylene diisocyanate and the like can be mentioned. Diamines that are derivatives of these aromatic diisocyanate compounds can also be used as raw materials. Examples of the aliphatic diisocyanate compound include ethylene diisocyanate, propylene diisocyanate, and hexamethylene diisocyanate. Examples of the alicyclic diisocyanate compound include 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, and the like. Among these diisocyanate compounds, considering the heat resistance, mechanical properties, solubility, and the like of the endless belt 1, 60% by mass or more, preferably 70% by mass or more of all the diisocyanate compounds used is diphenylmethane-4,4. It is preferable to use diamines that are '-diisocyanate, 2,4-toluene diisocyanate, 3,3'-dimethyl-4,4'-diisocyanate biphenyl, isophorone diisocyanate, or derivatives thereof. Furthermore, considering the dimensional stability of the endless belt 1, 70% by mass or more of all diisocyanate compounds used may be diphenylmethane-4,4′-diisocyanate or its derivative 4,4′-diaminodiphenylmethane. preferable.

  As the solvent used in the polycondensation reaction for synthesizing the aromatic polyamideimide resin, a polar solvent is preferable in terms of solubility, and an aprotic polar solvent is particularly preferable in consideration of reactivity. As aprotic polar solvents, for example, N, N-dialkylamides include, for example, N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylformamide, N, N-diethylacetamide, and N, N-dialkylamides such as N, N-dimethylmethoxyacetamide and the like. Further, as a polar solvent, N-methyl-2-pyrrolidone, pyridine, dimethyl sulfoxide, tetramethylene sulfone, dimethyltetramethylene sulfone, and the like are also preferable. These solvents can be used alone or in combination of two or more.

  The polyamideimide resin may contain a raw material for forming a polyamideimide resin, for example, the polyvalent carboxylic acid, the polyvalent amine, the polyvalent isocyanate, or the like, instead of part or all of the polyamideimide resin. Good. That is, the polyamide-imide resin contained in the endless belt 1 may be any component that becomes a polyamide-imide resin when formed into a ring shape.

  The silicone surfactant is terminated at the end in terms of excellent compatibility with the solvent used when synthesizing the aromatic polyamideimide resin and the solvent used when adjusting the viscosity of the polyamideimide resin composition described below. A reactive polysiloxane having a hydroxyl group, a silicone surface conditioner, a silicone surfactant called polyester-modified polydimethylsiloxane, and the like are preferable.

  Examples of the reactive polysiloxane having a hydroxyl group at the end include, for example, polyester-modified hydroxyl group-containing polydimethylsiloxane, polyether polyester-modified hydroxyl group-containing polydimethylsiloxane, and the terminal of silicone oil is modified with carbinol, and the terminal hydroxyl group derived from carbinol. A silicone oil having a hydroxyl group derived from a compound containing a hydroxycarbonyl group at the terminal by modifying the terminal of the silicone oil with a compound containing a hydroxycarbonyl group, for example, acyloin (referred to as carbinol-modified silicone oil) This is called carboxy-modified silicone oil.) A diol compound containing two hydroxy groups, such as ethylene glycol, is used to modify the end of the silicone oil to have a hydroxyl group derived from the diol compound at the end. That (referred to as a diol-modified silicone oil.) Silicone oil.

  The silicone surfactant is preferably a polyester-modified hydroxyl group-containing polydimethylsiloxane, a polyether polyester-modified hydroxyl group-containing polydimethylsiloxane, or a polyester-modified polydimethylsiloxane because it is more excellent in reducing the surface tension of the endless belt 1. More preferred are modified hydroxyl group-containing polydimethylsiloxane and polyester modified polydimethylsiloxane.

  The reactive polysiloxane having a hydroxyl group at the terminal is not particularly limited as long as it has a hydroxyl group at the terminal, and various reactive polysiloxanes can be mentioned. Specifically, examples of the polyester-modified hydroxyl group-containing polydimethylsiloxane include a trade name “BYK-370” (manufactured by BYK Chemie), and the polyether polyester-modified hydroxyl group-containing polydimethylsiloxane includes, for example, The trade name “BYK-375” (manufactured by Big Chemie), and the like, and the carbinol-modified silicone oil include, for example, the trade name “KF-6001” (manufactured by Shin-Etsu Chemical Co., Ltd.) and the like. Examples of the carboxyl-modified silicone oil include trade name “X-22-162C” (manufactured by Shin-Etsu Chemical Co., Ltd.). Examples of the diol-modified silicone oil include trade name “X-22-176DX”. (Shin-Etsu Chemical Co., Ltd.). Examples of the silicone surface conditioner include “silicone surface conditioners” (trade names “BYK UV3500”, “BYK UV3510”, and “BYK UV3570”, all manufactured by BYK Chemie), and the like. , And trade name “BYK-313” (manufactured by Big Chemie).

  The silicone surfactant in the present invention is different from the “chain silicone” of Patent Document 1 that does not function as a surfactant in that it functions as a surfactant.

  The silicone surfactant is preferably contained in a proportion of 0.1 to 2 parts by mass, and in a proportion of 0.1 to 1 part by mass, with respect to 100 parts by mass of the polyamideimide resin. Particularly preferred. When the silicone surfactant is contained within the above range, the endless belt 1 can run on the cleaning blade more smoothly.

Examples of the fluorine compound that is substantially free of the endless belt 1 include compounds having a perfluoroalkyl group (—C _n F _{2n + 1} ) in the molecule, and the perfluoroalkyl group has 1 to 1 carbon atoms. 6 perfluoroalkyl groups, particularly a perfluorobutyl group, a perfluorohexyl group, and the like. Examples of such a fluorine compound include a fluorine surfactant, and more specifically, a low molecular compound fluorine surfactant and an oligomer fluorine surfactant.

  The polyamideimide resin composition may contain various additives as long as the object of the present invention is not impaired. Examples of such additives include a conductivity imparting agent, a coupling agent, a lubricant, an antioxidant, a plasticizer, a colorant, an antistatic agent, an anti-aging agent, a reinforcing filler, a reaction aid, and a reaction. Various additives such as an inhibitor may be used. The polyamideimide resin composition may contain other resins as long as the object of the present invention is not impaired. The content of these other components in the polyamideimide resin composition can be appropriately determined according to the characteristics that are manifested in the polyamideimide resin composition by the addition of these other components. These additives are contained in the polyamideimide resin composition at an appropriate content.

As said electroconductivity imparting agent, electroconductive powder, an ion conductive substance, etc. can be mentioned, for example. As the conductive powder, for example, in addition to conductive carbon such as ketjen black and acetylene black, rubber carbons such as SAF, ISAF, HAF, FEF, GPF, SRF, FT and MT, titanium oxide, and oxidation Examples thereof include metals such as zinc, nickel, copper, silver, germanium, metal oxides, conductive polymers such as polyaniline, polypyrrole, and polyacetylene, and nanoparticles. Examples of the ion conductive material include inorganic ionic conductive materials such as sodium perchlorate, lithium perchlorate, calcium perchlorate, and lithium chloride. Among these, conductive carbon and carbon for rubber are preferable, and carbon black is particularly preferable. As the conductivity-imparting agent, one of these various substances can be used alone, or two or more of them can be used in combination. A preferable shape of the conductivity-imparting agent is spherical or irregular. The size of the particles of the conductivity-imparting agent having a spherical or irregular shape is preferably about 0.01 to 10 μm as the primary particle diameter. If conductive agent is carbon black, the BET specific surface area, strong correlation between the primary particle diameter is preferably ^{50~300m 2 / g, 100~200m 2 /} g is more preferable.

  The content of the conductivity-imparting agent in the polyamide-imide resin composition may be appropriately adjusted according to the conductivity and particle size of the conductivity-imparting agent and the conductive properties required for the endless belt 1. It is preferably 1 to 25% by mass, more preferably 5 to 20% by mass, and more preferably 10 to 20% by mass with respect to 100% by mass of the imide resin composition and the conductivity-imparting agent. Is particularly preferred. When the addition amount of the conductivity-imparting agent is less than 1% by mass, the distance between the conductive materials is too far away, and the expression of conductivity in the endless belt 1 may be deteriorated. On the other hand, the addition amount of the conductivity-imparting agent is low. When it exceeds 25 mass%, the mechanical strength of the endless belt 1 may be lowered. In order to disperse the conductivity-imparting agent in the resin, a known method can be appropriately selected. Examples of known methods include mixing rolls, pressure kneaders, extruders, three rolls, homogenizers, ball mills, pot mills, and the like. The mixing method using bead mill etc. is mentioned.

  The endless belt 1 is obtained by uniformly dispersing the polyamideimide resin, the silicone surfactant, and optionally various additives by a usual method, and curing and molding the resulting polyamideimide resin composition. . That is, the endless belt 1 is manufactured by molding the polyamideimide resin composition into a ring shape by a known molding method.

  For example, the endless belt 1 having a single layer structure is produced by molding the prepared polyamideimide resin composition into a ring shape by a known molding method. When a thermoplastic resin is selected as the resin contained in the polyamideimide resin composition forming the endless belt 1, when a thermosetting resin is selected as the resin by centrifugal molding, extrusion molding, injection molding, or the like The endless belt 1 can be formed by centrifugal molding, RIM molding, or the like. Among these molding methods, centrifugal molding is preferable in that it can be applied regardless of the material and is excellent in thickness accuracy.

  When the endless belt 1 is molded by centrifugal molding, the polyamideimide resin composition is preferably adjusted to have a viscosity of 50,000 mPa · s or less during molding. When the viscosity exceeds 50,000 mPa · s, it may be difficult to produce the endless belt 1 having a uniform thickness. The lower limit of the viscosity of the polyamideimide resin composition is not particularly limited, but is preferably 10 mPa · s or more. When the viscosity of the polyamideimide resin composition is outside the above range, the viscosity of the polyamideimide resin composition can be adjusted within the above range by adjusting the amount of the solvent added. As a solvent, the solvent used for the polycondensation reaction which synthesize | combines the said aromatic polyamideimide resin is mentioned.

  According to centrifugal molding, a polyamide-imide resin composition that exhibits fluidity by containing a solvent is poured into a cylindrical mold, and the mold is rotated and the polyamide-imide resin composition is formed on the inner peripheral surface of the mold by centrifugal force. The layer of the product is uniformly developed, and the solvent is dried and removed from the layer of the polyamideimide resin composition to produce an endless molded substrate. Various metal pipes can be used as the mold, and for example, a metal pipe whose inner peripheral surface is mirror-polished can be preferably cited. The inner peripheral surface of the mold may be subjected to a release treatment with a release agent such as a fluororesin or a silicone resin so that the formed endless molded substrate can be easily removed from the inner peripheral surface. In the case of using a mold subjected to release treatment, the endless belt according to the present invention can also be referred to as an endless belt formed using a mold subjected to release treatment.

  By the way, when the inner peripheral surface of the mold is released, the release agent remains on the surface of the manufactured endless belt, which rarely affects the surface characteristics to some extent. In particular, if the release agent does not remain uniformly on the surface, the surface characteristics of the endless belt also become non-uniform, and for example, the cleaning blade may be bent. On the other hand, since the endless belt according to the present invention originally contains a silicone surfactant, the inner peripheral surface of the mold does not have to be subjected to the release treatment. Problems such as non-uniformity of surface characteristics due to the remaining agent can be avoided. Thus, the endless belt according to the present invention formed using a mold that has not been subjected to release treatment can also be referred to as an endless belt having no release agent on its outer surface.

  In addition to the above-described centrifugal molding, a solution of polyamic acid in which tricarboxylic acid anhydride, which is a raw material of polyamideimide resin, and a diisocyanate compound are partially polymerized is immersed in the inner peripheral surface and outer peripheral surface of the mold, and centrifuged. It is coated by a method, a coating method, etc., or is developed into a cylindrical shape by an appropriate method such as filling the casting mold with the solution of the polyamic acid, and the developed layer is dried and formed into a belt shape. A known method of heat treating the molded product to convert the polyamic acid into an imide and recovering it from the mold (JP-A 61-95361, JP-A 64-22514, JP-A 3-180309, etc.) An endless molded substrate can also be produced by such means.

  The solvent is removed from the polyamideimide resin composition layer developed on the inner peripheral surface of the mold to produce an endless molded substrate. Here, the solvent to be removed is a solvent contained in the layer of the polyamideimide resin composition developed on the inner peripheral surface of the mold, and is used, for example, when adjusting the viscosity of the polyamideimide resin composition. In addition to the solvent, examples include a solvent used when the aromatic polyamideimide resin is synthesized. Examples of the treatment for removing the solvent from the polyamideimide resin composition layer developed on the inner peripheral surface of the mold include heat treatment. To remove the solvent, the following primary solvent removal step and secondary solvent can be used. It is preferable to perform a solvent removal treatment comprising a removal step.

  In the primary solvent removing step, the mold is formed while rotating the mold while removing the solvent from the polyamideimide resin composition layer developed on the inner peripheral surface of the mold, and the polyamideimide resin composition layer is formed into a film-like molded body. And In the primary solvent removal step, the solvent is removed by passing hot air of 40 to 150 ° C. through the mold for 5 to 60 minutes while rotating the mold. When the hot air temperature exceeds 150 ° C. and / or when the heating time exceeds 60 minutes, the molded film-like molded body may be oxidized.

  In the secondary solvent removing step, the film-like molded body formed in the primary solvent removing step is taken out from the centrifugal molding machine together with the mold, heated together with the mold to remove the solvent from the film-shaped molded body, To do. For example, when using a heater such as a hot air dryer or oven, the film-like molded body may be heated together with the mold at 200 to 300 ° C. for 1 to 3 hours, and when a superheated steam furnace is used. What is necessary is just to heat a film-like molded object for 0.5 to 3 hours with 200-260 degreeC superheated steam with a metal mold | die. In addition, if a deformation | transformation etc. of a film-shaped molded object can be prevented, a film-shaped molded object can be demolded from a metal mold | die, and a film-shaped molded object can also be heated on the said conditions.

  After producing an endless molded substrate from which the solvent has been removed in this manner, the endless molded substrate is taken out of the mold and allowed to cool. When the endless molded substrate is allowed to cool together with the mold, the endless molded substrate can be removed due to the difference in thermal expansion coefficient between the mold and the endless molded substrate.

  After removing the endless molded substrate in this way, both end portions of the annular endless molded substrate are removed and cut into a predetermined width. The cutting machine that cuts the endless molded substrate may be an apparatus that can cut the endless molded substrate so that the cutting start point and the cutting end point substantially coincide with each other. In this way, the endless belt 1 having a single layer structure made of only the resin layer is manufactured.

  The endless belt 1 manufactured in this manner contains a polyamide-imide resin and a silicone surfactant, and the endless belt 1 travels on the cleaning blade without giving an excessive load and excessive vibration to the cleaning blade. It can pass smoothly. As a result, the endless belt 1 can smoothly travel on the endless track over a long period of time even if the traveling speed is high, and can maintain the initial pressure contact state with the cleaning blade. In other words, the endless belt 1 can prevent the cleaning blade from turning over for a long period of time. Thus, according to the present invention, it is possible to provide an endless belt that can travel without bending the cleaning blade pressed against the outer surface.

  The endless belt according to the present invention is not limited to the above-described embodiments, and various modifications can be made within a range in which the object of the present invention can be achieved. For example, the endless belt 1 is composed of a resin layer having a single layer structure. However, in the present invention, the endless belt may have a multilayer structure in which two or more layers are laminated. In this case, an adhesive layer or a primer layer may be formed between the layers.

  The endless belt having the multilayer structure includes another layer formed on the outer surface or the inner surface of the resin layer, and is capable of maintaining the initial pressure contact state with the cleaning blade. It is preferable to provide another layer formed on the surface. Examples of the other layer include a base layer, a coat layer, a surface layer, and an elastic layer. The endless belt having such a multilayer structure is manufactured, for example, by forming another layer on the outer surface or inner surface of the resin layer formed in an annular shape as described above. Specifically, for example, in order to produce an endless belt having a multi-layer structure including other layers on the outer surface of the resin layer, the outer surface of the resin layer formed in an annular shape is formed on the outer surface of the resin layer in the same manner as the endless belt 1. A method of forming another layer is adopted. Here, the material for forming the other layer is appropriately selected according to the characteristics required for the other layer. For example, when the other layer is a coat layer, a desired resin composition is selected. When the layer is an elastic layer, a desired rubber composition or elastomer composition is selected. Then, these materials are applied to the outer peripheral surface of the resin layer by a dipping method, a spray method, a roll coater method, a doctor blade coating method, or the like, and cured to form another layer on the outer surface of the resin layer. be able to.

  On the other hand, in order to produce a multi-layered endless belt having other layers on the inner surface of the resin layer, the resin layer is formed on the inner surface of the other layer formed in the same manner as the endless belt 1. Is adopted. Here, the material for forming the other layer is appropriately selected according to the properties required for the other layer. For example, when the other layer is an elastic layer, the rubber composition or the elastomer composition may be used. Selected. Then, to form a resin layer on the inner surface of the other layer, the material is applied to the inner surface of the other layer by a dipping method, a spray method, a roll coater method, a doctor blade coating method, etc., and cured. The method to be made can be selected.

  In the present invention, the endless belt is provided with a string-like or belt-like elongated guide member made of an elastic material, if desired, on at least one end in the axial direction of the endless belt on the inner peripheral surface of the endless belt. May be. This guide member functions as a guide for preventing side shake while the endless belt is running. Examples of the material for the guide member include elastic materials having appropriate rubber elasticity and wear resistance, such as urethane elastomers, silicone elastomers, fluororesin elastomers, and styrene elastomers. Among these, urethane-based elastomers having an A hardness of 30 or more and 95 or less according to JIS K 6253-1997, which is excellent in wear resistance, are preferable. Preferably, the guide member is provided so as to go around the inner peripheral surface of the endless belt base at both ends in the axial direction of the endless belt base.

  Since the endless belt according to the present invention can maintain the initial pressure contact state with the cleaning blade for a long period of time, the endless belt is attached to the image forming apparatus so that the cleaning blade is in pressure contact. That is, the endless belt according to the present invention is suitably used in an image forming apparatus including a cleaning blade whose one end or one end edge is pressed against the outer surface thereof, and constitutes an endless belt unit together with the cleaning blade. As shown in FIG. 2, an endless belt unit 50 according to an embodiment of the endless belt unit according to the present invention includes an endless belt 1 wound around a plurality of rotating bodies, for example, support rollers 42, and traveling on an endless track. A cleaning blade 51 is provided in pressure contact with the outer surface of the endless belt 1. Since the endless belt constituting the endless belt unit according to the present invention is basically the same as the endless belt 1, description thereof will be omitted. As will be described later, the cleaning blade constituting the endless belt unit according to the present invention usually removes the developer attached or transferred to the endless belt.

  The cleaning blade 51 only needs to include an elastic body 53 that presses against the outer surface of the endless belt 1. For example, as illustrated in FIGS. 2 and 3, the cleaning blade 51 includes a support body 52, an elastic body 53, and the like. I have.

  As shown in FIG. 3, the support 52 has a plate-like portion 55 extending in one direction, and substantially extends from one end edge to the plate-like portion 55 along one longitudinal edge of the plate-like portion 55. The mounting portion 56 is formed so as to extend vertically. That is, the support body 52 is formed as a plate-like member having a substantially L-shaped cross section in a cross section perpendicular to the longitudinal direction. The support 52 supports an elastic body 53 to be described later, and makes the elastic body 53 contact the endless belt 1 with a desired pressing load. Therefore, the support body 52 is formed of a material that can support the elastic body 53, such as a metal material. In general, the support 52 preferably has a thickness of 50 to 250 μm, and particularly preferably has a thickness of 80 to 120 μm. The support 52 preferably has a uniform thickness over the entire surface. The support body 52 is adjusted so that the length in the longitudinal direction is longer than the length in the axial direction of the endless belt 1.

  The elastic body 53 can be formed in an arbitrary shape. For example, as shown in FIGS. 2 and 3, the elastic body 53 is formed in a rectangular plate shape or a rectangular parallelepiped having a predetermined thickness. The elastic body 53 has one end portion or one end edge 54A (referred to as a front end pressure contact portion) abutted against the endless belt 1 with a desired pressing load, and the non-functional outer surface 6 of the endless belt 1 (see FIG. 2). Slide on the top. As described above, when the tip pressure contact portion 54A of the elastic body 53 slides on the non-functional outer surface 6, the developer or the like attached to the non-functional outer surface 6 can be effectively removed. Here, the non-functional outer surface 6 is an outer surface of the endless belt 1 and is in a track in which the endless belt 1 does not function in an endless track of the endless belt 1 (in other words, in a return track). The outer surface. For example, the endless belt 1 in FIG. 2 refers to an outer surface on which the recording body 16 is not held and transported after the recording body 16 is transported to the fixing device 30.

  The elastic body 53 is formed of an elastic material having elasticity, for example, urethane rubber, silicone rubber, or the like so as not to damage the endless belt 1. Examples of the urethane rubber include thermoplastic urethane rubber. More specifically, urethane rubber using polyester polyol and polyether polyol as a polyol component, and tolylene diisocyanate, diphenylmethane diisocyanate, and an isocyanate component. Examples include urethane rubber using hexamethylene diisocyanate and the like. Examples of the silicone rubber include HTV rubber (high temperature curable millable silicone rubber, etc.), liquid silicone rubber (LTV, RTV, etc.) and the like.

  The thickness of the elastic body 53 is adjusted to an arbitrary thickness, specifically 0.1 to 3 mm. The elastic body 53 preferably has a uniform thickness over the entire surface. Further, like the support body 52, the elastic body 53 is preferably adjusted so that the length in the longitudinal direction is longer than the length in the axial direction of the endless belt 1. The length in the vertical direction, that is, the width, is not particularly limited, and is adjusted to, for example, about 10 to 30 mm.

  Since the elastic body 53 is in pressure contact with the endless belt 1, the JIS A hardness (JIS K 6253-1997) is preferably in the range of 40 to 90, and particularly preferably in the range of 50 to 80. Further, since the elastic body 53 is pressed against the endless belt 1, it is preferable that the tensile permanent strain characteristic (25% strain, 70 ° C., 22 hours) according to JIS K6262 is 50% or less.

  The elastic body 53 slides on the non-functional outer surface 6 of the endless belt 1 and removes the developer adhering to the outer surface of the endless belt 1, so that JIS-K7311 (load 1 Kg, wear wheel H-22). The amount of wear measured at 1000 rpm is preferably 50 mg or less.

  In the cleaning blade 51, the support body 52 and the elastic body 53 are respectively made of the above-described materials by a known method, and if desired, an adhesive is applied to the support body 52, and the elastic body 53 is overlaid on the applied adhesive. It can be produced by curing the adhesive by a known method.

  As shown in FIG. 2, the endless belt unit 50 includes the endless belt 1 and the cleaning blade 51, and the cleaning blade 51 is wound around the endless belt 1, on the downstream side in the traveling direction of the endless track. It is arranged in the vicinity of the downstream direction of the support roller 42 located. That is, the cleaning blade 51 is disposed in the vicinity of the downstream side of the support roller 42 that converts the forward path to the return path during the return path after the forward path in which the endless belt 1 holds and conveys the recording medium and transfers it to the fixing device. Has been. In the cleaning blade 51, the outer surface 5 when the endless belt 1 holds and conveys the recording medium 16 (sometimes referred to as a recording medium conveying outer surface) releases the recording medium 16 to the fixing device. The non-functional outer surface 6 after being transferred is pressed against the developing unit Y side of the image forming apparatus 10 so as to be pressed. At this time, the cleaning blade 51 only needs to have its tip pressure contact portion 54A in pressure contact with the non-functional outer surface 6, and in other words, the length direction of the tip pressure contact portion 54A extends along the axis of the endless belt 1. The endless belt 1 is preferably pressed against the non-functional outer surface 6 so as to be substantially perpendicular to the traveling direction. In particular, in the cleaning blade 51, as shown in FIG. 2, the tip pressure contact portion 54A is located upstream of the traveling direction of the endless belt 1 (the direction indicated by the arrow A in FIG. 2), and the width direction of the tip pressure contact portion 54A. It is preferable that the other end edge 54 </ b> B is disposed on the downstream side with respect to the traveling direction of the endless belt 1. When the cleaning blade 51 is arranged in this way, the tip pressure contact portion 54A comes into pressure contact with the non-functional outer surface 6 of the endless belt 1 from the direction opposite to the traveling direction of the endless belt 1, so The attached developer can be highly removed.

  As shown in FIG. 2, the cleaning blade 51 has a virtual line (not shown in FIGS. 2 and 3) in the width direction of the elastic body 53 and a virtual line of the endless belt 1 in a state where the cleaning blade 51 is not in contact. It is particularly preferable that the pressure contact angle θ formed with the running surface is in pressure contact with the non-functional outer surface 6 of the endless belt 1 such that the pressure contact angle θ is in a range of 15 ° to 25 °. The pressure load P applied to the non-functional outer surface 6 of the cleaning blade 51 is preferably 0.2 to 2 MPa when the pressure angle θ is in the above range. When the cleaning blade 51 is in pressure contact with the non-functional outer surface 6 so as to have the pressure contact angle θ and the pressure contact load P, the pressure contact state with the endless belt 1 can be maintained over a long period of time, and the endless belt 1 The developer attached to the outer surface can be removed as desired.

  Since the endless belt unit 50 includes the endless belt 1 and the cleaning blade 51, the endless belt 1 does not give an excessive load and excessive vibration to the elastic body 53 of the cleaning blade 51, and the elastic body of the cleaning blade 51. 53 can smoothly travel and pass. As a result, the endless belt unit 50 can maintain the initial pressure contact state between the endless belt 1 and the cleaning blade 51 for a long period of time, even if the endless belt 1 travels at a high speed. Thus, according to the present invention, it is possible to provide an endless belt unit capable of maintaining the initial pressure contact state between the endless belt and the cleaning blade for a long period of time.

  The endless belt unit according to the present invention is not limited to the above-described embodiments, and various modifications can be made within a range where the object of the present invention can be achieved. For example, the endless belt unit 1 includes one cleaning blade 51. However, in the present invention, the endless belt unit may include a plurality of cleaning blades.

  As described above, the endless belt and the endless belt unit according to the present invention are attached to the image forming apparatus. In particular, the endless belt and the endless belt unit according to the present invention can maintain the initial pressure contact state between the endless belt and the cleaning blade for a long period of time, so that the printing speed, that is, the traveling speed of the endless belt is increased. It is suitably used for a forming apparatus. Since the endless belt unit according to the present invention includes the cleaning blade, the endless belt according to the present invention mounted on the image forming apparatus is mounted as a belt to which the developer adheres or is transferred in the image forming apparatus. It is good. Examples of such belts include a transfer conveyance belt that conveys a recording medium onto which a developer is transferred during conveyance while conveying the recording medium, an intermediate transfer belt of a secondary transfer type image forming apparatus, and a fixing roller of a fixing apparatus. And a fixing belt for fixing the developer onto the recording medium.

  An example of an image forming apparatus provided with an endless belt 1 according to the present invention and an endless belt unit 50 according to the present invention will be described with reference to the drawings. As shown in FIG. 2, the image forming apparatus 10 includes a plurality of image carriers 11B, 11C, 11M, and 11Y that are mounted on the developing units B, C, M, and Y of each color in series on an endless belt 1. Therefore, the developing units B, C, M, and Y are arranged in series on the endless belt 1.

  In the tandem type color image forming apparatus 10, as shown in FIG. 2, the endless belt 1 of the present invention is a transfer conveyance belt that conveys the recording medium onto which the developer is transferred on the outer surface during conveyance. 1, the outer peripheral surface is mounted so as to be in pressure contact with the cleaning blade 51. That is, as shown in FIG. 2, the image forming apparatus 10 includes a transfer conveyance belt 1 wound around a plurality of rotating bodies, for example, support rollers 42, and traveling on an endless track in the direction of arrow A in FIG. An endless belt unit 50 having a cleaning blade 51 that is disposed on the downstream side in the traveling direction of the endless track and presses against the outer surface of the transfer conveyance belt 1 after releasing the recording medium 16 is provided. As described above, the cleaning blade 51 is in pressure contact with the non-functional outer surface 6 of the transfer conveyance belt 1 so that the tip pressure contact portion 54A has the pressure contact angle θ and the pressure load P in the above-described range.

  Of the outer surface of the transfer / conveying belt 1 that runs while being wound around two support rollers 42, the side on which developing units B, C, M, and Y, which will be described later, are disposed, holding the recording body 16 ( The outer surface of the transfer conveyance belt 1 traveling on the outward path side is referred to as a recording medium conveyance outer surface 5, and the held recording medium 16 is released so that the development units B, C, M, and Y are not disposed ( The outer surface of the transfer conveyance belt 1 traveling on the return path side is referred to as a non-functional outer surface 6.

  As shown in FIG. 2, the developing unit B in the image forming apparatus 10 includes an image carrier 11B such as a photoreceptor (also referred to as a photosensitive drum), a charging unit 12B such as a charging roller, an exposure unit 13B, and a developing unit. Means 20B, transfer means 14B that contacts the image carrier 11B via the transfer conveyance belt 1, for example, a transfer roller, and an image carrier cleaning means 15B are provided. The developing unit 20B adjusts the thickness of the casing 21B that accommodates the one-component non-magnetic developer 22B, the developer carrier 23B that supplies the developer 22B to the image carrier 11B, such as a developing roller, and the thickness of the developer 22B. Developer amount adjusting means 24B, for example, a blade. The developing units C, M, and Y are basically configured in the same manner as the developing unit B. The fixing device 30 is disposed on the downstream side of the developing unit Y, and as shown in a cross section in FIG. 2, a fixing roller 31 and a fixing roller 31 are provided in a housing 34 having an opening 35 through which the recording medium 16 passes. An endless belt support roller 33 disposed in the vicinity of the fixing roller 31, a fixing belt 36 wound around the fixing roller 31 and the endless belt support roller 33, and a pressure roller 32 disposed to face the fixing roller 31. The pressure heat fixing device is configured such that the fixing roller 31 and the pressure roller 32 are rotatably supported so as to be in contact with or in pressure contact with each other via the unit 36. At the bottom of the image forming apparatus 10, a cassette 41 that houses the recording medium 16 is installed.

  Each of the developers 22B, 22C, 22M and 22Y used in the image forming apparatus 10 may be a dry developer or a wet developer as long as it can be charged by friction, and a non-magnetic developer or a magnetic developer. An agent may be used. One component non-magnetic black developer 22B, cyan developer 22C, magenta developer 22M and yellow developer 22Y are accommodated in the housings 21B, 21C, 21M and 21Y of the developing units.

  The recording medium 16 used in the image forming apparatus 10 is not particularly limited as long as it is a recording medium 16 capable of fixing a developer, and examples thereof include normal sheet paper, high-quality paper, and medium-quality paper. Since the endless belt 1 which is an embodiment of the endless belt according to the present invention is attached to the image forming apparatus 10 as a transfer conveyance belt, even if it is a replenishment sheet that is easy to adhere to the developer and is difficult to remove. , The adhered developer can be removed as desired.

  The image forming apparatus 10 forms a color image on the recording body 16 as follows. First, in the developing unit B, an electrostatic latent image is formed by the exposure unit 13B on the surface of the image carrier 11B charged by the charging unit 12, and the black electrostatic image is generated by the developer 22B supplied by the developer carrier 23B. The latent image is developed. The black electrostatic latent image is transferred to the surface of the recording medium 16B when the recording medium 16 passes between the transfer means 14B and the image carrier 11B. Next, in the same manner as in the developing unit B, a cyan image, a magenta image, and a yellow image are superimposed on the recording medium 16 in which the electrostatic latent image is visualized as a black image by the developing units C, M, and Y, respectively. A color image is visualized. Next, the recording body 16 in which the color image is visualized is fixed to the recording body 16 by the fixing unit 30 as a permanent image. In this way, a color image can be formed on the recording medium 16.

  In the image forming apparatus 10, as described above, when the developers 22B, 22C, 22M, and 22Y are transferred to the recording medium 16 by the developing units B, C, M, and Y, the developers 22B, 22C, 22M and 22Y may be scattered on the transfer / conveying belt 1 in some cases. However, since the image forming apparatus 10 includes the endless belt unit 50 according to the present invention, the developer attached to the outer peripheral surface of the endless belt 1 can be removed as desired over a long period of time. Therefore, according to the present invention, it is possible to provide an image forming apparatus that can maintain the initial pressure contact state between the endless belt and the cleaning blade for a long period of time and can form a high-quality image.

  The image forming apparatus 10 is an image forming apparatus such as a copying machine, a facsimile machine, or a printer. The image forming apparatus 10 is an electrophotographic image forming apparatus. However, in the present invention, the image forming apparatus is not limited to the electrophotographic system. For example, the image forming apparatus 10 is an electrostatic image forming apparatus. Also good. Further, an endless belt according to the present invention and an image forming apparatus to which the endless belt unit according to the present invention is attached include a tandem type color image forming apparatus in which a plurality of image carriers having developing units of respective colors are arranged in series on a transfer conveyance belt. For example, a monochrome image forming apparatus having a single developing unit, a four-cycle color image forming apparatus that repeats primary transfer of a developer image carried on an image carrier to an endless belt in sequence, for example. Etc. The developer used in the image forming apparatus 10 is a one-component non-magnetic developer. However, in the present invention, a one-component magnetic developer or a two-component non-magnetic developer may be used. Or a two-component magnetic developer.

Example 1
In a reaction vessel, N-methyl-2-pyrrolidone, trimellitic anhydride, an equivalent amount of diphenylmethane-4,4′-diisocyanate, and reaction raw materials (trimellitic anhydride and diphenylmethane-4,4′- 2 mol% of potassium fluoride (catalyst) is added to the total number of moles of diisocyanate), and the temperature is raised from room temperature to 150 ° C. over 30 minutes with stirring. (Substantially fully ring-closed polyamideimide resin) A 20% by mass aromatic polyamideimide solution was obtained. N-methyl-2-pyrrolidone was further added to this solution to prepare a polyamideimide solution having a reactant concentration of 15% by mass.

  In the polyamideimide solution thus obtained, carbon black (trade name “Special Black 4”, manufactured by Degussa) is 15% by mass with respect to 100% by mass in total of the polyamideimide resin and carbon black. In addition, polyetherpolyamide-modified hydroxyl group-containing polydimethylsiloxane (trade name “BYK375”, manufactured by Big Chemie) is added in a proportion of 0.5 parts by mass with respect to 100 parts by mass of the polyamideimide resin (solid content). In addition, a polyamideimide resin composition was prepared by mixing and dispersing in a bead mill for 24 hours. In addition, the fluorine compound is not added to this polyamideimide resin composition.

  On the other hand, ring-shaped lids (inner diameter 170 mm, outer diameter) are provided at both ends of a cylindrical mold having an inner diameter of 226 mm, an outer diameter of 246 mm, and an axial length of 400 mm, and the inner surface of the mold is mirror-polished by polishing. 250 mm) was fitted to close the cylindrical mold, and a molding mold was prepared. In addition, the mold inner surface is not subjected to mold release treatment with a silicone resin as a mold release agent.

  190 g of the prepared polyamideimide resin composition was injected into the inner periphery of a molding die rotating at a speed of 1,000 rpm. Next, the molding die was rotated at the same speed for 30 minutes to uniformly spread the polyamideimide resin composition layer on the inner peripheral surface of the molding die. Next, while rotating the molding die at the same speed, the temperature around the molding die was kept at 80 ° C. with a hot air dryer, and this state was maintained for 30 minutes to form a film-like molded body. Thereafter, the rotation of the molding die is stopped, the film-like molded body is taken out from the centrifugal molding machine together with the molding die, subjected to superheated steam treatment in a superheated steam furnace adjusted to 250 ° C. for 2 hours, and then allowed to cool at room temperature. An endless molded substrate was obtained. The endless molding substrate was cooled together with the molding die, the endless molding substrate was peeled off due to the difference in thermal expansion coefficient between the molding die and the endless molding substrate, and the endless molding substrate was removed from the molding die. Both end portions of the removed endless molded substrate were each cut and cut into a size having a circumference of about 710 mm, a width of 240 mm, and a thickness of 100 μm to produce an endless belt.

(Example 2)
Instead of the polyether polyester-modified hydroxyl group-containing polydimethylsiloxane (trade name “BYK375”), a polyester-modified polydimethylsiloxane (trade name “BYK313”, manufactured by BYK Chemie) was used with respect to 100 parts by mass of polyamideimide resin (solid content). An endless belt was produced in the same manner as in Example 1 except that it was added so that the ratio was 0.3 parts by mass.

(Comparative Example 1)
An endless belt was produced in the same manner as in Example 1 except that the polyether polyester-modified hydroxyl group-containing polydimethylsiloxane (trade name “BYK375”) was not added.

(Production of cleaning blade)
A polyester polyol (trade name “Desmophen 1652”, manufactured by Sumika Bayer Urethane Co., Ltd.) and an equivalent amount of hexamethylene diisocyanate polyisocyanate (trade name “Sumijour N3300”, manufactured by Sumika Bayer Urethane Co., Ltd.) are weighed and mixed in a beaker. Thus, a urethane raw material was prepared. On the other hand, a ring-shaped lid (inner diameter 170 mm, outer (Diameter 250 mm) was fitted, the cylindrical mold was closed, and a molding mold was prepared. The prepared urethane raw material was poured into the inner periphery of a molding die rotating at a speed of 1,000 rpm so that the thickness after drying was 2 mm. Next, while rotating the molding die at the same speed, the temperature around the molding die was maintained at 150 ° C. with a hot air dryer, and this state was maintained for 30 minutes to form a cylindrical urethane molded body. Thereafter, the rotation of the molding die is stopped, and the cylindrical urethane molded body is taken out of the centrifugal molding machine together with the molding die and cooled, and then cut by a cutting machine to obtain a thickness of 2.0 mm (of the molding die). A substantially plate-like urethane elastic body cut to a width of 20 mm (in a direction matching the circumferential direction) and a length of 250 mm (in a direction matching the axial direction of the molding die) and slightly curved along the width direction Produced.

  The urethane elastic body thus produced was bonded to an iron support 52 having a thickness of 1.0 mm, a width of 20 mm, and a length of 250 mm to produce a cleaning blade 51. As shown in FIG. 3, the urethane elastic body was bonded to the support body 52 so that the surface of 10 mm width × 250 mm length overlapped. The urethane elastic body had a JIS A hardness of 70, a tensile set characteristic of 50%, and a wear amount of 50 mg in the measurement method.

(Measurement of friction coefficient between endless belt and urethane blade)
A test sheet and a surface property measuring instrument (trade name “14FW”, manufactured by Shinto Kagaku Co., Ltd.) cut from each endless belt manufactured in Examples and Comparative Examples to a circumferential length of 200 mm and an axial length of 100 mm. ) And measuring the static friction coefficient and the dynamic friction coefficient of the test sheet a plurality of times according to the measurement method using the prepared cleaning blade, and calculating the arithmetic average value as the static friction coefficient and the dynamic friction coefficient of each test sheet. Asked. The obtained values were defined as the static friction coefficient and the dynamic friction coefficient of the endless belt. The results are shown in Table 1.

(Physical properties of endless belt)
Sliding angle, torque, torque fluctuation amount, contact angle of n-dodecane, surface resistivity, volume resistivity, Young's modulus, softness test, tensile strength, tensile elongation of each endless belt manufactured in Examples and Comparative Examples, Table 1 shows the results of measuring the tear strength and flame retardancy according to the above methods.

(Content of silicone surfactant in endless belt)
Each endless belt manufactured in Examples and Comparative Examples was analyzed by a photoelectron spectrometer (ESCA) (trade name “1600S”, manufactured by PHI). As a result, the content of the silicone surfactant contained in each endless belt substantially matched the content of the silicone surfactant in the polyamideimide resin composition forming each endless belt. When each endless belt was analyzed by a photoelectron spectrometer (ESCA) in the same manner as the silicone surfactant, no fluorine compound was found in any of the endless belts.

(Evaluation of bending of urethane blade)
An endless belt unit testing apparatus similar to the image forming apparatus shown in FIG. 2 (for example, trade name “MicroLine C5800n”, manufactured by Oki Data Co., Ltd.), for example, the torque measuring device 70 shown in FIG. The end edge of the cleaning blade 51 is pressed against the endless belt 1 so that the contact angle θ between each endless belt and the cleaning blade 51 is 23 ° and the pressing load P is 1 MPa. Each of the endless belts was run at 15 rpm for 10 minutes. This running test was repeated 10 times for each endless belt, and the number of times the cleaning blade turned over during running of the endless belt was counted to calculate the percentage of cleaning blade turning. The evaluation was “accepted” when the dripping rate (%) was less than 10%, which was actually acceptable, and “failed” when the dripping rate (%) exceeded 10%. The results are shown in Table 1.

1 Endless belt (transfer conveyor belt)
5 Non-functional outer surface 10 Image forming apparatus 11, 11B, 11C, 11M, 11Y Image carrier 12, 12B, 12C, 12M, 12Y Charging means 13, 13B, 13C, 13M, 13Y Exposure means 14 , 14B, 14C, 14M, 14Y Transfer means 15B, 15C, 15M, 15Y Image carrier cleaning blade 16 Recording body 20B, 20C, 20M, 20Y Developing means 21B, 21C, 21M, 21Y Housings 22B, 22C, 22M, 22Y Developer 23B, 23C, 23M, 23Y Developer carrier 24B, 24C, 24M, 24Y Developer amount adjusting means 30 Fixing device 31 Fixing roller 32 Pressure roller 33 Fixing belt support roller 34 Housing 35 Opening 36 Fixing belt 41 Cassette 42 Support roller 50 Endless belt unit 51 Cleaning Blade 52 Support body 53 Elastic body 54A Tip pressure contact portion 54B Other end edge 55 Plate-like portion 56 Mounting portion B, C, M, Y Developing unit

60 Sliding angle measuring device 61 Stage 62 Measuring device 63 Fixing portion 64 First support rod 65 Second support rod 66 Test piece 67 Contact member 70 Torque measurement device 71 Stretching portion 71a, 71b Roller 71c Support body 72 Drive portion 73 Measurement portion 74 Wearing part

Claims (3)

  An endless belt comprising a resin layer containing a polyamideimide resin and a silicone surfactant and having a cleaning blade pressed against an outer surface.   The endless belt according to claim 1, wherein the silicone surfactant is contained in the resin layer at a ratio of 0.1 to 2 parts by mass with respect to 100 parts by mass of the polyamideimide resin.   An endless belt unit comprising the endless belt according to claim 1 or 2 wound around a plurality of rotating bodies and traveling on an endless track, and a cleaning blade pressed against the outer surface of the endless belt.

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