JP2015184541A - Removal member and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a removal member which hardly causes abnormal noise, abrasion, and cracks at the tip compared to one that has a peak temperature of the loss tangent of greater than or equal to 0 degree Celsius at a contact part, or less than 0 degree or greater than or equal to 10 degrees at a support part.SOLUTION: A removal member 361 is a cleaning blade having a so-called two layer structure, and includes a contact part 3611 and a support part 3612. The contact part 3611 contacts with an image holding body 31 to remove substances such as toner attached to a surface of the image holding body 31. A first material contained in the contact part 3611 is a material adjusted so that the peak temperature of the loss tangent is less than 0 degree Celsius. The support part 3612 supports the contact part 3611 from the opposite side of a part of the contact part 3611, which contacts with the image holding body 31. A second material contained in the support part 3612 is a material adjusted so that the peak temperature of the loss tangent is greater than or equal to 0 degree Celsius and less than 10 degrees. The substances scooped down by the contact part 3611 of the removal member 361 are stored in a case 360.

Description

  The present invention relates to a removing member and an image forming apparatus.

Patent Document 1 discloses a two-layered cleaning blade having a cleaning unit including an edge part for scraping off deposits on an image carrier and a support part for pressing the cleaning unit against the image carrier. The cleaning part is composed of a composite rubber material whose tan δ peak temperature (described later) is close to the surface temperature of the image carrier, and the support part is composed of a composite rubber material whose tan δ peak temperature is lower than the tan δ peak temperature of the cleaning part. A cleaning blade is described.
Patent Document 2 describes a blade member in which an edge layer is formed of a material having a tan δ peak temperature of less than 10 ° C. and a value of 100% modulus at 23 ° C. of 6 MPa to 12 MPa.

JP 2002-55582 A JP 2011-197309 A

  According to the present invention, noise, sag, and chipping of the tip occur compared to a loss tangent peak temperature of 0 degree Celsius or higher at the contact portion or a support portion of less than 0 degree Celsius or 10 degrees Celsius or higher. An object is to provide a difficult removal member.

  The removal member according to claim 1 of the present invention is formed of a first material having a peak loss tangent peak temperature of less than 0 degrees Celsius, and contacts the image carrier to remove a substance attached to the image carrier. And a supporting part that supports the contact part from the opposite side of the part in contact with the image carrier, the second material having a loss tangent peak temperature of 0 degrees Celsius or more and less than 10 degrees Celsius. It is characterized by that.

The removal member according to claim 2 of the present invention is characterized in that, in the aspect described in claim 1, the first material has a value of 100% modulus of 6 megapascals or more.
An image forming apparatus according to a third aspect of the present invention is the removal member according to the first or second aspect and an image holding body that holds an image formed on a medium, and the adhered material is removed by the removal member. And an image carrier.

According to the first and third aspects of the invention, compared to the loss tangent peak temperature of 0 degree Celsius or higher at the contact portion or the support portion having a peak temperature of less than 0 degree Celsius or 10 degrees Celsius or higher, , And chipping of the tip is less likely to occur.
According to the second aspect of the present invention, the loss tangent peak temperature is in contact with the image carrier as compared with those having a peak temperature of 0 degrees Celsius or higher at the contact portion and those having a support portion of less than 0 degrees Celsius or 10 degrees Celsius or higher. The amount of wear on the part is reduced.

1 is a diagram illustrating an overall configuration of an image forming apparatus according to an embodiment of the present invention. The figure which shows the structure of a drum cleaner. The figure which shows the test result of chipping cycle evaluation. The figure which shows the test result of abnormal noise evaluation. The figure which shows the test result of a sticky amount evaluation. The figure which shows the test result of wear amount evaluation. The figure which shows the structure of the drum cleaner in a modification.

1. Embodiment 1-1. 1 is a diagram showing an overall configuration of an image forming apparatus 1 according to an embodiment of the present invention. As illustrated in FIG. 1, the image forming apparatus 1 includes a developing unit 13, a transfer unit 14, a fixing unit 15, and a conveyance unit 16.
The conveyance part 16 has a container and a conveyance roll. The container stores paper P as a medium. The paper P stored in the container is taken out one by one by a transport roll according to an instruction from a control unit (not shown), and is transported to the transfer unit 14 via a paper transport path. The medium is not limited to paper, and may be a resin sheet, for example. In short, the medium may be any medium that can record an image on the surface.

  The developing unit 13 includes an image carrier 31, a charger 32, an exposure device 33, a developing device 34, a primary transfer roll 35, and a drum cleaner 36. The image carrier 31 is a photosensitive drum having a charge generation layer and a charge transport layer, and is rotated in the direction of an arrow D13 in the drawing by a driving unit (not shown). The charger 32 charges the surface of the image carrier 31. The exposure device 33 includes a laser light source, a polygon mirror, and the like (both not shown), and after the laser light corresponding to the image data is charged by the charger 32 under the control of a control unit (not shown). Irradiation toward the image carrier 31. As a result, the latent image is held on the image holder 31. Note that the image data may be acquired from an external device by the image forming apparatus 1 via a communication unit (not shown). The external device is, for example, a reading device that reads an original image or a storage device that stores data indicating an image. The developing device 34 supplies the developer to the image carrier 31. As a result, an image is formed (developed) on the image carrier 31.

  The primary transfer roll 35 generates a predetermined potential difference at a position where the intermediate transfer belt 41 of the transfer unit 14 faces the image carrier 31, and the image is transferred to the intermediate transfer belt 41 by this potential difference. The drum cleaner 36 removes untransferred toner remaining on the surface of the image carrier 31 after the image is transferred, and neutralizes the surface of the image carrier 31.

  The transfer unit 14 includes an intermediate transfer belt 41, a secondary transfer roll 42, a belt transport roll 43, a backup roll 44, and a belt cleaner 49, and an image formed by the developing unit 13 is transferred to a sheet P It is a transfer part to transfer to. The intermediate transfer belt 41 is an endless belt member, and the belt conveyance roll 43 and the backup roll 44 stretch the intermediate transfer belt 41. At least one of the belt conveyance roll 43 and the backup roll 44 is provided with a drive unit (not shown), and moves the intermediate transfer belt 41 in the direction of arrow D14 in FIG. Note that the belt conveyance roll 43 or the backup roll 44 that does not have a driving unit rotates as the intermediate transfer belt 41 moves. As the intermediate transfer belt 41 moves and rotates in the direction of arrow D14 in FIG. 1, the image on the intermediate transfer belt 41 is moved to a region sandwiched between the secondary transfer roll 42 and the backup roll 44.

  The secondary transfer roll 42 transfers the image on the intermediate transfer belt 41 onto the paper P conveyed from the conveyance unit 16 by a potential difference with the intermediate transfer belt 41. The belt cleaner 49 removes untransferred toner remaining on the surface of the intermediate transfer belt 41. Then, the transfer unit 14 or the conveyance unit 16 conveys the paper P on which the image is transferred to the fixing unit 15. The fixing unit 15 fixes the image transferred onto the paper P by heating.

1-2. Configuration of Drum Cleaner FIG. 2 is a diagram illustrating a configuration of the drum cleaner 36. As shown in FIG. 2, the drum cleaner 36 includes a case 360, a removing member 361, and a holding member 362. In addition, the drum cleaner 36 may have a mechanism for discharging the surface of the image carrier 31 or a mechanism for supplying a lubricant to the surface.

  The case 360 is a housing having an opening on the side facing the image carrier 31 and includes a holding member 362 fixed to the ceiling plate. The holding member 362 holds one end of the removing member 361 and exposes the other end from the opening of the case 360 to determine a predetermined pressure (hereinafter referred to as contact pressure) and a predetermined angle (hereinafter referred to as contact angle). Then, the image holding member 31 is brought into contact. As shown in FIG. 2, the angle θ between the tangential plane at the contact point of the image carrier 31 and the direction in which the contact portion 3611 of the removal member 361 extends is the contact angle.

  The removing member 361 is a so-called two-layer cleaning blade, and includes a contact portion 3611 and a support portion 3612. The contact part 3611 contacts the image carrier 31 and removes substances such as toner adhering to the surface of the image carrier 31. The support part 3612 supports the contact part 3611 from the side opposite to the part where the contact part 3611 contacts the image carrier 31. The substance scraped off by the contact portion 3611 of the removing member 361 is accommodated in the case 360 and removed from the image forming apparatus 1 during maintenance.

  The holding member 362 shown in FIG. 2 holds the support portion 3612 side of the removal member 361, but may hold the contact portion 3611 side, or both the contact portion 3611 and the support portion 3612. The removal member 361 may be held in contact with.

  As the materials for the contact portion 3611 and the support portion 3612, those satisfying the following rules are used. That is, the first material forming the contact portion 3611 is a material adjusted so that the peak temperature of the loss tangent is less than 0 degrees Celsius. The second material constituting the support portion 3612 is a material adjusted so that the peak temperature of the loss tangent is 0 degree Celsius or more and less than 10 degrees Celsius.

  Here, the loss tangent (hereinafter also referred to as “tan δ”) is the “loss tangent” defined in K6394-2007 “Vulcanized rubber and thermoplastic rubber? And the storage elastic modulus. The loss tangent varies depending on the material type and temperature. The loss tangent peak temperature (hereinafter also referred to as “tan δ peak temperature”) refers to a temperature at which the loss tangent becomes maximum in a glass transition region of a certain material. “δ” of tan δ is a loss angle.

  Each of the first material and the second material is, for example, polyurethane produced by reacting a polyol, a polyisocyanate, and a crosslinking agent.

As the polyol, polyester polyol obtained by dehydration condensation of diol and dibasic acid, polycarbonate polyol obtained by reaction of diol and alkyl carbonate, caprolactone-based polyol, polyether polyol and the like are used.
Examples of the polyisocyanate to be reacted with a polyol include 4,4'-diphenylmethane diisocyanate (MDI), 2,6-toluene diisocyanate (TDI), 1,6-hexane diisocyanate (HDI), and 1,5-naphthalene diisocyanate. (NDI) and 3,3-dimethylphenyl-4,4-diisocyanate (TODI) are used.
As the crosslinking agent, diol (bifunctional), triol (trifunctional), diamino compound (bifunctional) and the like are used.

  The first material and the second material satisfying the above-mentioned regulations are manufactured by blending polyisocyanate with the polyol and the crosslinking agent described above, and adjusting and reacting the weight part of the isocyanate, the weight part and the ratio of the crosslinking agent, and the like. Is done.

  By configuring the contact portion 3611 with the first material satisfying the above-described regulations and configuring the support portion 3612 with the second material satisfying the above-mentioned regulations, the removal member 361 has a noise and a settling compared to the conventional removal member. , And the tip is less likely to be chipped.

2. Test Example tan δ peak temperature was measured for a plurality of materials in which the ratios of polyol, crosslinking agent, and polyisocyanate were adjusted, and various performances when these materials were used in combination as the contact portion 3611 or the support portion 3612, respectively. evaluated.

In addition, as a method for measuring the tan δ peak temperature of the material, specifically, a dynamic viscoelasticity automatic measuring device: Leo Vibron (manufactured by Orientec Co., Ltd.) is used, and the measurement frequency is 10 Hz and 0.1 from the low temperature side (−45 ° C.) The temperature was raised to the high temperature side (35 ° C.) at a rate of ° C./min.
The tan δ at each temperature is obtained by fixing both ends of the test piece to a measuring machine, applying a certain tension, applying a strain at 10 Hz, thereby measuring the stress generated in the test, decomposing it into an elastic stress, and further The storage elastic modulus and the loss elastic modulus were calculated and obtained by dividing the loss elastic modulus by the storage elastic modulus. And the temperature which shows the highest value among tan-delta in each calculated | required temperature was specified as tan-delta peak temperature.

2-1. Chip cycle evaluation The chip cycle evaluation was performed as follows. The removal member 361 using the obtained plurality of materials for the contact part 3611 is mounted on DocuCentre-IVC5575 manufactured by Fuji Xerox Co., Ltd., the contact pressure is adjusted to 2.0 gf / mm, the contact angle is adjusted to 11 °, the temperature is 10 ° C. Evaluation was performed at a relative humidity of 15%. A projection of 50 micrometers (μm) is provided on the surface of the image carrier 31 and the blade tip, that is, the portion where the contact portion 3611 contacts the image carrier 31 is observed every 25 cycles of the image carrier 31. The number of cycles in which the occurrence of chipping was observed was defined as the number of chipping cycles. In addition, since the number of missing cycles is “0”, it is a case where a defect has occurred at any point in the first 25 cycles. For example, this includes the case where the occurrence of a defect is observed at the point of one cycle. .

  FIG. 3 is a diagram showing a test result of chipping cycle evaluation. The horizontal axis in FIG. 3 represents the tan δ peak temperature (Celsius) of the substance used as the first material constituting the contact portion 3611. The vertical axis in FIG. 3 is the number of missing cycles. As shown in FIG. 3, when the tan δ peak temperature of the first material is 0 ° C. or more, the number of chip cycles is 0 or 25, and when the tan δ peak temperature of the first material is less than 0 ° C., the number of chip cycles is 100 or more. Met. Therefore, it was found that the occurrence of chipping at the tip is suppressed by adjusting the first material so that the tan δ peak temperature is less than 0 ° C.

2-2. Abnormal noise evaluation The abnormal noise evaluation was performed as follows. The removal member 361 using the obtained plurality of materials for the support portion 3612 is mounted on DocuCentre-IVC5575 manufactured by Fuji Xerox Co., Ltd., the contact pressure is adjusted to 2.0 gf / mm, the contact angle is adjusted to 11 °, the temperature is 28 ° C. An abnormal sound evaluation was performed by a person listening to the sound when 200 times of image formation was performed on a white paper medium at a relative humidity of 85%.

  FIG. 4 is a diagram showing test results of abnormal noise evaluation. The horizontal axis in FIG. 4 is the tan δ peak temperature (Celsius) of the substance used as the second material constituting the support portion 3612. The horizontal axis of FIG. 4 is an index (hereinafter referred to as an abnormal noise index) for evaluating an abnormal noise heard by a person during the 200th image formation. The abnormal sound index means that “0” is not generated, “1” is slight abnormal noise generation, “2” is abnormal noise generation, and “3” is annoying abnormal noise generation.

  As shown in FIG. 4, when the tan δ peak temperature of the second material is less than 0 ° C., the abnormal sound index is 1 or more, but when the tan δ peak temperature of the second material is 0 ° C. or higher, the abnormal sound index is 0. there were. Therefore, it was found that the generation of abnormal noise is suppressed by adjusting the second material so that the tan δ peak temperature is 0 ° C. or higher.

2-3. Splash amount evaluation Splash evaluation was performed as follows. The removal member 361 using each of the obtained plurality of materials for the support portion 3612 is incorporated in the drum cleaner 36 of DocuCentre-IVC5575 manufactured by Fuji Xerox Co., Ltd., and the amount of biting of the removal member 361 into the image carrier 31 is 1.5 mm. The samples were left at a temperature of 50 ° C. and a relative humidity of 95% for 1 month. Then, the amount of biting after being allowed to stand was measured, and the amount of change from the initial setting was defined as a set amount. It has been found that the larger the amount of settling, the lower the contact pressure of the removing member 361 and, for example, the occurrence of toner slipping, so that the removal performance decreases.

  FIG. 5 is a diagram showing test results for evaluation of the amount of settling. The horizontal axis in FIG. 5 represents the tan δ peak temperature (Celsius) of the substance used as the second material constituting the support portion 3612. The horizontal axis in FIG. 5 represents the amount of settling (millimeters) after the above-mentioned leaving.

  As shown in FIG. 5, when the tan δ peak temperature of the second material is 10 ° C. or higher, the amount of sag is 0.27 or higher, but when the tan δ peak temperature of the second material is less than 10 ° C., the amount of sag is 0. It was less than 13. Therefore, it has been found that by adjusting the second material so that the tan δ peak temperature is less than 10 ° C., the occurrence of sag is suppressed.

3. Modification The above is the description of the embodiment, but the contents of this embodiment can be modified as follows. Further, the following modifications may be combined.
3-1. Modification 1
In addition to the above-mentioned definition, the first material may be adjusted so that the value of 100% modulus is 6 megapascals or more. The value of 100% modulus is “predetermined elongation tensile stress” defined in JIS K6251-2010 “vulcanized rubber and thermoplastic rubber? How to obtain tensile properties”. Is the value obtained by dividing the tensile force by the initial cross-sectional area of the test piece. Here, 25 degreeC is employ | adopted as test temperature. Thereby, wear of contact part 3611 constituted by the 1st material is controlled.

  A value of 100% modulus was measured for a plurality of adjusted materials, and an amount of wear when the plurality of materials were used as the contact portion 3611 was evaluated. The amount of wear was evaluated as follows. A removal member 361 using the obtained plurality of materials for the contact part 3611 is mounted on DocuCentre-IVC5575 manufactured by Fuji Xerox Co., Ltd., the contact pressure is adjusted to 2.0 gf / mm, the contact angle is adjusted to 11 °, the temperature is 28 ° C., After forming 20,000 images at a relative humidity of 85%, 20,000 images were formed at a temperature of 10 ° C. and a relative humidity of 15%, for a total of 40,000 images. The amount of wear at the tip was measured by observing the cross-sectional profile with a laser microscope VK-9500 manufactured by Keyence Corporation, and measuring the cross-sectional area of the worn portion.

FIG. 6 is a diagram showing a test result of wear amount evaluation. The horizontal axis in FIG. 6 is the value of 100% modulus (megapascal) of the substance used as the first material constituting the contact portion 3611. The horizontal axis in FIG. 6 represents the amount of wear after standing (square micrometer: 1 × 10 ⁻¹² m ² ).

  As shown in FIG. 6, when the value of 100% modulus of the first material is less than 6 megapascals, the wear amount is 2.8 square micrometers or more, but the value of 100% modulus of the first material is 6 megapascals. Above Pascal, the amount of wear was less than 2.8 square micrometers. Therefore, it was found that the wear of the contact portion 3611 is suppressed by adjusting the first material so that the value of the 100% modulus is 6 megapascals or more.

3-2. Modification 2
In the embodiment described above, the image forming apparatus 1 has only one developing unit 13, but may have a plurality of developing units 13. In this case, the image forming apparatus 1 includes a corresponding image holding member 31, a charger 32, an exposure device 33, a developing device 34, a primary transfer roll 35, and a drum cleaner 36. As long as it has. The plurality of developing units 13 may form toner images of different colors. In this case, toner images of different colors are transferred onto the intermediate transfer belt 41 and a color image is formed on a medium such as paper P.

3-3. Modification 3
In the embodiment described above, the removing member 361 is used for the drum cleaner 36, but may be used for the belt cleaner 49. In this case, the removing member 361 may remove the substance attached to the intermediate transfer belt 41 instead of the image carrier 31. The image carrier 31 and the intermediate transfer belt 41 are both examples of an image carrier that holds an image formed on a medium.

3-4. Modification 4
In the embodiment described above, the contact portion 3611 and the support portion 3612 of the removal member 361 have the same length as illustrated in FIG. 2, but may have different lengths and shapes.
FIG. 7 is a diagram showing a configuration of the drum cleaner 36 in this modification. As shown in FIG. 7, the contact portion 3611 may be a member shorter than the support portion 3612. In FIG. 2, the contact portion 3611 and the support portion 3612 are rectangular as viewed from the axial direction of the image holding member 31.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 13 ... Developing part, 14 ... Transfer part, 15 ... Fixing part, 16 ... Conveying part, 31 ... Image carrier, 32 ... Charger, 33 ... Exposure device, 34 ... Developing apparatus, 35 ... Primary Transfer roller, 36 ... drum cleaner, 360 ... case, 361 ... removal member, 3611 ... contact portion, 3612 ... support portion, 362 ... holding member, 41 ... intermediate transfer belt, 42 ... secondary transfer roll, 43 ... belt conveying roll 44 ... backup roll, 49 ... belt cleaner.

Claims (3)

A contact portion made of a first material having a loss tangent peak temperature of less than 0 degrees Celsius, and contacting the image carrier to remove a substance attached to the image carrier;
The loss tangent peak temperature is made of a second material having a temperature of 0 degree Celsius or more and less than 10 degrees Celsius, and the contact part has a support part that supports the contact part from the side opposite to the part in contact with the image carrier. A featured removal member. The removal member according to claim 1, wherein the first material has a value of 100% modulus of 6 megapascals or more. The removal member according to claim 1 or 2,
An image holding body for holding an image formed on a medium, the image holding body for removing attached substances by the removing member.

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