JP2014191024A - Pressure member for fixation, fixing device, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure roll that suppresses peeling of an elastic layer from a base material over time under a heavier nip load than before, compared to the case not having the present configuration.SOLUTION: A pressure roll 80 includes a core bar 82, an elastic layer 84 formed on an outer peripheral surface of the core bar 82, and a release layer 86 formed on an outer peripheral layer of the elastic layer 84. The core bar 82 has on the periphery a pleated or fibrous reinforcement layer 88.

Description

  The present invention relates to a fixing pressure member, a fixing device, and an image forming apparatus.

  As a fixing method of a toner image in an electrophotographic image forming apparatus, a heating member heated by a heat source, a pressure member formed on an outer peripheral surface with an elastic layer using a material such as rubber in which bubbles are present, and There is a fixing method using. In such a fixing method, a pressure member is pressed against a heating member that is circulated and the elastic layer of the pressure member is crushed so that a contact region having a width in the circumferential direction of the pressure member (hereinafter referred to as “nip portion”) is also obtained. And the recording medium on which the toner image is formed enters the contact area, and the toner image is melted and pressurized to be fixed on the recording medium.

  As a pressure member used in the fixing method of the above aspect, for example, Patent Document 1 discloses a pressure roller in which a fluororesin tube having a thickness of 0.1 mm or less is attached to the outer periphery of a silicone sponge rubber coated on the outer periphery of a core metal. A method of forming a pressure roller in which silicone powder is added to the silicone sponge rubber is disclosed.

  Patent Document 2 discloses a method of forming a roller by providing a foam layer on a peripheral surface of a core material and using the foam layer as a polyimide foam.

  Patent Document 3 discloses an elastic member including a release layer, an elastic layer, and a base layer as constituent layers, wherein the release layer is a fluororesin film, and the elastic layer is a porous fluororesin film. There is disclosed a method of forming an elastic member excellent in releasability, in which pores are filled with an elastic body, and the release layer is the outermost layer and is in contact with the elastic layer.

  In Patent Document 4, in a roller having a porous elastic layer made of polyimide on the surface of a core shaft, the polyimide has an outer diameter that gradually increases from a central portion to both end portions of the roller. A porous elastic layer made of is formed in a drum shape. A release layer composed of polyimide is preferably provided on the surface of the porous elastic layer composed of polyimide. Further, a method is disclosed in which the release layer is preferably covered with minute protrusions.

  Patent Document 5 discloses a fixing device roller in which a foam material layer having open cells, a solid elastic layer, an adhesive layer, and a release layer are laminated in this order on a cored bar. A method of forming a roller for a fixing device in which a through hole extending from the adhesive layer side to the foaming material layer side is provided in the elastic layer, and the through hole is filled with an adhesive constituting the adhesive layer. It is disclosed.

JP 7-137176 A JP 2002-31664 A JP 2005-257762 A JP 2008-116557 A JP 2012-163829 A

  An object of the present invention is a pressure member for fixing that has high heat insulation, little thermal expansion, and does not cause uneven melting of toner when fixing a toner image even at a high nip load, and has excellent durability. It is an object of the present invention to provide a fixing pressure member, a fixing device using the same, and an image forming apparatus.

  As a result of intensive studies to solve the above problems, the present invention has been reached as follows.

  (1) a cylindrical base material, a heat resistant elastomer containing hollow heat resistant particles laminated on the cylindrical base material, or an elastic layer of a heat resistant elastomer made of a foam having communication holes; A release layer made of a heat-resistant resin having releasability in the outermost layer, and a semi-foamed reinforcing heat-resistant resin is bonded to the surface of the base material, and the reinforcing heat-resistant resin is The fixing pressure member is embedded in the elastic layer.

  (2) The fixing pressure member according to (1), wherein the heat-resistant elastomer is silicone rubber, and the semi-foaming heat-resistant resin bonded to the surface of the base material is polyimide. .

  (3) The fixing pressure member according to (1) or (2), a heating device, heated by the heating device, pressed against the fixing pressure member, and the fixing pressure member. A heating and fixing member that forms a contact area therebetween and heats and pressurizes and fixes the toner image while rotating around the recording medium having a toner image formed on the surface of the contact area. is there.

  (4) a latent image forming means for forming a latent image on the image holding member, a developing means for developing the latent image using a developer for developing an electrostatic image, and the developed toner image via an intermediate transfer member. The image forming apparatus includes: a transfer unit that transfers the toner image on the transfer body; and a fixing unit that fixes the toner image on the transfer body. The fixing unit is described in (3) above. The image forming apparatus includes a fixing device.

  According to the first aspect of the present invention, as compared with the case where the present configuration is not provided, peeling between the base material and the elastic layer over time at a higher nip load than that in the past is suppressed.

  According to the invention described in claim 2 of the present application, as compared with the case where the present configuration is not provided, peeling of the base material and the elastic layer over time at a higher nip load than that in the past is suppressed.

  According to the third aspect of the present invention, there is provided a fixing pressure member that suppresses the peeling between the base material and the elastic layer over time at a higher nip load than in the conventional case, as compared to the case without this configuration. A fixing device having the same is obtained.

  According to the invention described in claim 4 of the present application, compared with the case where the present configuration is not provided, the pressure member for fixing that suppresses the peeling between the base material and the elastic layer over time at a higher nip load than in the past. An image forming apparatus provided with the fixing device is obtained.

1 is a schematic configuration diagram illustrating an example of a configuration of an image forming apparatus according to the present invention. FIG. 2 is a schematic configuration diagram illustrating an example of a configuration of a fixing device according to the present invention. It is sectional drawing which shows an example of the pressurization member for fixing in this invention. It is a sectional view showing an example of a conventional fixing pressure member. It is a figure explaining an example of the manufacturing method of the pressure member for fixing of this invention. It is a schematic diagram showing an example of the structure of a heat-resistant resin for reinforcement formed on the surface of a base material of a fixing pressure member in the present invention and embedded in an elastic layer. It is a schematic diagram which shows the other example of the structure of the heat resistant resin for reinforcement formed in the surface of the base material of the pressurizing member in this invention, and embed | buried in the elastic layer. It is a schematic diagram which shows the other example of the structure of the heat resistant resin for reinforcement formed in the surface of the base material of the pressurizing member in this invention, and embed | buried in the elastic layer.

  A fixing pressure member, a fixing device, and an image forming apparatus according to an embodiment of the present invention will be described below.

[Image forming apparatus]
FIG. 1 shows a schematic configuration of an image forming apparatus to which the sliding sheet and the fixing device of the present embodiment are applied. Here, an intermediate transfer type image forming apparatus generally called a tandem type will be described as an example.

  An image forming apparatus 100 shown in FIG. 1 includes a plurality of image forming units 1Y, 1M, 1C, and 1K that form toner images of respective color components by an electrophotographic method as an example of an image forming unit including a latent image forming unit and a developing unit. Is provided. Next, the image forming apparatus 100 sequentially transfers (primary transfer) each color component toner image formed by each image forming unit 1Y, 1M, 1C, 1K to an intermediate transfer belt (image holding member) 15 as an example of a transfer unit. ) And a secondary transfer unit 20 that collectively transfers (secondary transfer) the superimposed toner image transferred onto the intermediate transfer belt 15 to a sheet of recording medium P (recording material). Furthermore, the image forming apparatus 100 includes the above-described fixing device 90 that fixes the secondary transferred image on the recording medium P as an example of a fixing unit. Further, the image forming apparatus 100 includes a control unit 40 that controls the operation of each device (each unit).

  As shown in FIG. 1, each of the image forming units 1Y, 1M, 1C, and 1K includes a photosensitive drum 11 that rotates in the direction of arrow A, a charger 12 that charges the photosensitive drum 11, and a photosensitive drum 11. It has a laser exposure device 13 for writing an electrostatic latent image, and a developing device 14 that accommodates each color component toner and visualizes the electrostatic latent image on the photosensitive drum 11 with the toner. Also, a primary transfer roll 16 that transfers each color component toner image formed on the photosensitive drum 11 to the intermediate transfer belt 15 in the primary transfer unit 10, a drum cleaner 17 that removes residual toner on the photosensitive drum 11, and Have These image forming units 1Y, 1M, 1C, and 1K are arranged substantially linearly in the order of yellow (Y), magenta (M), cyan (C), and black (K) from the upstream side of the intermediate transfer belt 15. ing.

  The intermediate transfer belt 15 is circulated and driven in the direction of arrow B shown in FIG. As various rolls, a drive roll 31 that drives the intermediate transfer belt 15, a support roll 32 that supports the intermediate transfer belt 15, a tension roll 33 that applies a constant tension to the intermediate transfer belt 15 to prevent meandering, and a secondary transfer. A backup roll 25 provided in the section 20 and a cleaning backup roll 34 provided in a cleaning section for scraping the residual toner on the intermediate transfer belt 15 are provided.

  The primary transfer unit 10 includes a primary transfer roll 16 that faces the photosensitive drum 11 with the intermediate transfer belt 15 interposed therebetween. The secondary transfer unit 20 is disposed on the back side of the intermediate transfer belt 15 as a secondary transfer roll (transfer member) 22 disposed on the toner image holding surface side of the intermediate transfer belt 15 and a counter electrode of the secondary transfer roll 22. And a power supply roll 26 that applies a secondary transfer bias to the backup roll 25.

  An intermediate transfer belt cleaner 35 for removing residual toner and paper dust on the intermediate transfer belt 15 is provided on the downstream side of the secondary transfer unit 20. A reference sensor (home position sensor) 42 that generates a reference signal for taking an image forming timing in each of the image forming units 1Y, 1M, 1C, and 1K is disposed upstream of the yellow image forming unit 1Y. Further, an image density sensor 43 for adjusting image quality is disposed on the downstream side of the black image forming unit 1K.

  The recording medium transport system includes a recording medium storage unit 50, a pickup roll 51 that takes out and transports the recording medium P in the recording medium storage unit 50, a transport roll 52 that transports the recording medium P, and a secondary recording medium P. A conveyance chute 53 to be transferred to the transfer unit 20, a conveyance belt 55 for conveying the recording medium P secondary-transferred by the secondary transfer roll 22 to the fixing device 90, and a fixing inlet guide for guiding the recording medium P to the fixing device 90. 56.

  A basic image forming process of the image forming apparatus 100 will be described. In an image forming apparatus 100 as shown in FIG. 1, after image processing is performed on image data output from an image reading device (not shown) or the like, the image data is converted into four colors Y, M, C, and K. It is converted into material gradation data and output to the laser exposure unit 13. For example, each of the photosensitive drums that rotates the exposure beam Bm emitted from the semiconductor laser in the direction of arrow A of the image forming units 1Y, 1M, 1C, and 1K according to the input color material gradation data. 11 is irradiated. After the surface of each photoconductive drum 11 is charged by the charger 12, the surface is scanned and exposed by the laser exposure device 13 to form an electrostatic latent image. The formed electrostatic latent image is developed as a toner image of each color of Y, M, C, and K by each image forming unit 1Y, 1M, 1C, 1K.

  Next, the toner image formed on the photosensitive drum 11 is sequentially superimposed on the surface of the intermediate transfer belt 15 in the primary transfer unit 10 to perform primary transfer. The intermediate transfer belt 15 moves in the direction of arrow B and conveys the toner image to the secondary transfer unit 20. The recording medium conveyance system supplies the recording medium P from the recording medium container 50 in accordance with the timing at which the toner image is conveyed to the secondary transfer unit 20. In the secondary transfer unit 20, the unfixed toner image held on the intermediate transfer belt 15 is electrostatically transferred onto the recording medium P sandwiched between the intermediate transfer belt 15 and the secondary transfer roll 22. Thereafter, the recording medium P on which the toner image has been electrostatically transferred is conveyed to the fixing device 90 by the conveying belt 55, and the fixing device 90 processes the unfixed toner image on the recording medium P with heat and pressure and puts it on the recording medium P. To settle. The recording medium P on which the fixed image has been formed is conveyed to a paper discharge placement unit provided in the discharge unit of the image forming apparatus.

  As shown in FIG. 1, the fixing device 90 includes a pressure roll and a heat fixing belt. The pressure roll is rotated by a driving device (not shown), and the heat-fixing belt is rotated around the pressure roll. The pressure roll and the heat fixing belt fix the unfixed toner image on the paper P by heating and pressurizing the paper P with the paper P interposed therebetween. A more detailed configuration of the fixing device will be described later.

  In the embodiment described above, a tandem type color printer is shown as an example of the image forming apparatus. However, the image forming apparatus referred to in the present embodiment is not limited to this, and is, for example, a monochrome printer having no intermediate transfer belt. There may be.

  In the embodiment described above, a printer is shown as an example of the image forming apparatus. However, the image forming apparatus referred to in the present embodiment is not limited to a printer, and for example, an image is formed based on data read by an image reading apparatus. It may be a copying machine or a facsimile machine.

[Fixing device]
Here, the fixing device constituting the image forming apparatus shown in FIG. 2 will be described. The fixing device 90 is an embodiment of the fixing device of the present embodiment.

  FIG. 2 is a schematic cross-sectional view showing the configuration of the fixing device 90 shown in FIG. The fixing device 90 is an electromagnetic induction heating type fixing device. The fixing device 90 is configured by providing a heat fixing belt 70, a pressure member having a pressure pad 72 and a holder 74, a pressure roll 80, and a magnetic field generator 60 inside a housing.

  Here, the pressure roll 80 corresponds to an example of a pressure member in the present invention, the heat fixing belt 70 corresponds to an example of a heat fixing member in the present invention, and the magnetic field generator 60 corresponds to an example of a heating device in the present invention. Equivalent to.

  As shown in FIG. 2, a heat fixing belt 70 is sandwiched between the lower surface of the pressure member and the outer peripheral surface of the pressure roll 80. Both ends of a cored bar 82 (corresponding to a “cylindrical base”) of the pressure roll 80 are supported by bearings (not shown) so that the pressure roll 80 can freely rotate. An upward force is applied to the bearing by a spring, and the outer peripheral surface of the pressure roll 80 is pressed against the lower surface of the pressure member via the heat fixing belt 70 by this force. Since the elastic layer 84 and the release layer 86 of the pressure roll 80 can be elastically deformed, the periphery of the pressure roll 80 is interposed between the heat fixing belt 70 and the pressure roll 80 as shown in FIG. A contact area (also referred to as a “nip”) having a width in the direction is formed.

  The pressure roll 80 is rotated in the direction of arrow B in FIG. When the pressure roll 80 rotates, a frictional force acts on the outer peripheral surface of the heat fixing belt 70, and the inner peripheral surface of the heat fixing belt 70 is driven in the direction of arrow C while rubbing the lower surface of the pressure member. In this case, in order to reduce a frictional force generated between the lower surface of the pressure member and the inner peripheral surface of the heat fixing belt 70, a heat resistant grease or the like is provided between the lower surface of the pressure member and the inner peripheral surface of the heat fixing belt 70. It is desirable to interpose a lubricant.

  The magnetic field generator 60 generates an alternating magnetic flux for generating heat in a heat generating layer of the heat fixing belt 70 described later. The magnetic field generator 60 includes an excitation circuit 64, a magnetic core 63, an excitation coil 62, and an excitation coil holding member 66. The magnetic core 63 is formed of a material having high magnetic permeability such as ferrite or permalloy. The excitation circuit 64 generates an alternating current of 20 kHz to 500 kHz. The exciting coil 62 generates an alternating magnetic flux by the alternating current supplied from the exciting circuit 64. The exciting coil 62 is formed, for example, by winding a bundle of a plurality of copper wires each of which is coated with an insulating material a plurality of times. The magnetic core 63 and the excitation coil 62 are formed along the outer peripheral surface of the heat fixing belt 70 held in a cylindrical shape. In the present embodiment, the distance between the outer surface of the heat fixing belt 70 and the exciting coil 62 is set to 2 mm.

  The pressure member is obtained by mounting a pressure pad 72 made of silicone rubber or the like on the holder 74. In the pressure pad 72 in the present embodiment, the hardness of the silicone rubber is 20 ° (JIS-A). The holder 74 is made of a metal such as stainless steel or a synthetic resin having high heat resistance.

  The heat fixing belt 70 is an annular belt and has a layered structure in which a base material layer, a heat generating layer, an elastic layer, and a release layer are laminated in order from the inner surface side.

  The base material layer is formed of a resin having high heat resistance with a thickness of 10 μm to 100 μm, for example. Examples of the resin include polyester, polyethylene terephthalate, polyether sulfone, polyether ketone, polysulfone, polyimide, polyimide amide, and polyamide. In the present embodiment, polyimide having a thickness of 50 μm is used.

  As the heat generation layer, a layer in which a metal layer such as iron, cobalt, nickel, copper, and chromium is formed with a thickness of 1 μm or more and 50 μm or less is used. It is desirable to make the thickness of the heat generating layer thinner so that the heat fixing belt is deformed along the shape of the pressure member. In the present embodiment, as the heat generation layer, copper having a high conductivity plated on the base material layer with a thickness of 10 μm so as to increase the heat generation efficiency is used.

  The elastic layer is formed of silicone rubber, fluorine rubber, fluorosilicon rubber, or the like, which is a material having good heat resistance and thermal conductivity. The thickness of the elastic layer is preferably 10 μm or more and 500 μm or less, and more preferably 50 μm or more and 500 μm or less. In this embodiment, the thickness of the elastic layer is 300 μm. The hardness of the elastic layer is preferably 60 ° (JIS-A: JIS-KA type tester) or less, and more preferably 45 ° or less.

  The release layer is preferably formed of a material having good release properties and heat resistance such as fluororesin such as PFA, PTFE, FEP, silicone resin, silicone rubber, fluororubber and the like. The thickness of the release layer is preferably 20 μm or more and 100 μm or less. In this embodiment, the thickness of the release layer is 30 μm.

  In the heating and fixing belt 70, the alternating magnetic flux generated by the exciting coil 62 in the magnetic field generator 60 acts on the heat generating layer, whereby an eddy current is generated in the heat generating layer and heat is generated in the heat generating layer. The heat generated in the heat generating layer is formed on the sheet P conveyed in the direction of arrow A through the elastic layer and the release layer of the heat fixing belt 70 in the contact area between the heat fixing belt 70 and the pressure roll 80. The toner image T is transmitted to the toner image T, and the toner image is fixed.

[Pressure member]
Here, a pressure roll 80 will be described as an example of a fixing pressure member constituting the fixing device shown in FIG. FIG. 3 is a cross-sectional view showing an example of the configuration of the pressure roll in the present embodiment.

  The pressure roll 80 includes a cored bar 82, an elastic layer 84 formed on the outer peripheral surface of the cored bar 82, and a release layer 86 formed on the outer peripheral surface of the elastic layer 84.

  For the cored bar 82, for example, a cylindrical member having a diameter of 18 mm made of iron plated with nickel is used. A semi-foamed heat resistant resin is joined to the surface of the core metal. The thickness of the heat resistant resin is not more than the thickness of the elastic layer covering the cored bar, and is preferably about 20% to 70%. As the heat resistant resin, a polyimide resin is preferable from the viewpoint of heat resistance, and polyamideimide, polyetherimide, polybenzimidazole, and the like are used. The foamed state is not particularly specified, but it is strong enough to communicate toward the outer peripheral surface and to have a reinforcing effect (anchor effect) for the heat-resistant elastomer, and does not greatly hinder the elastic deformation of the heat-resistant elastomer. It must be flexible. Moreover, it is preferable to apply an adhesive from the viewpoint of obtaining good adhesion between the heat-resistant elastomer and the heat-resistant resin formed on the outer peripheral surface of the cored bar 82.

  In the present embodiment, a pleated or fibrous reinforcing layer 88 having a height of about 2 to 3 mm and released toward the outer peripheral surface made of polyimide resin is formed on the outer periphery of the cored bar 82.

  In the present embodiment, for example, as shown in FIG. 6, the reinforcing layer 88 has a thin film of heat-resistant resin formed on the surface of the cored bar 82, and intermittently formed semi-foamed heat-resistant resin protrusions. Alternatively, as shown in FIG. 7, a heat resistant resin strip-like sheet may be spirally wound around the surface of the cored bar 82 to form protrusions of the heat resistant resin. Alternatively, as shown in FIG. 8, a configuration in which a tangled fibrous heat-resistant resin is partially bonded to the surface of the cored bar 82 may be used.

  The elastic layer 84 is formed of a heat-resistant elastomer containing hollow heat-resistant particles so as to cover the entire outer peripheral surface of the cored bar 82, or a heat-resistant elastomer made of a continuous foam, and the heat-resistant elastomer may be silicone. Rubber, fluorine rubber or the like is used, and silicone rubber is particularly preferable. The heat-resistant elastomer needs to be in a liquid state in an uncured state in order to fill the voids of the semi-foamed heat-resistant resin provided on the surface of the core metal 82. As the heat-resistant elastomer containing hollow heat-resistant particles, it is possible to use commercially available hollow glass beads or epoxy resin hollow bodies dispersed in liquid silicone rubber (LSR). As the heat-resistant elastomer made of a continuous foam, an emulsion composition for forming a silicone rubber foam can be used.

  The elastic layer 84 preferably has a thickness of 2 mm or more and 20 mm or less, more preferably 3 mm or more and 10 mm or less, including the semi-foamed heat resistant resin. In the present embodiment, the elastic layer 84 is formed of a liquid silicone rubber filled with hollow glass beads as a layer having a thickness of 5 mm, and the hardness is adjusted to 60 ° (Asker-C).

  The release layer 86 is made of PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), PTFE (polytetrafluoroethylene), FEP (tetrafluoroethylene-hexafluoropropylene copolymer), silicone resin, silicone rubber, fluorine. It is formed of a material having good releasability and heat resistance such as rubber and fluorinated polyimide. The release layer 86 is formed so as to cover the entire outer peripheral surface of the elastic layer 84, and the thickness is preferably 10 μm or more and 200 μm or less, and more preferably 20 μm or more and 100 μm or less. The release layer 86 preferably contains a conductive agent such as carbon black in the fluorine resin in order to prevent electrostatic offset. In this embodiment, the release layer is formed as a 30 μm thick layer by PFA.

  By the way, heat is transmitted from a pair of pressure members to the pressure member for fixing (hereinafter simply referred to as “pressure member”) applied to the fixing device when the fixing device is operated. If the thermal conductivity is high, heat is taken from the pressure member side, and the warm-up time becomes long. On the other hand, the thermal conductivity can be reduced while keeping the thermal expansion low by adding hollow particles to the elastic layer of the fixing pressure member shown in FIG. It is conceivable that the elastic layer will break when used for a long time due to lack of durability. In particular, when the pressure member for fixing is the pressure roll 180, the metal core 182 is used after a long time of use. In some cases, breakage is likely to occur at the interface between the elastic layer 184 and the elastic layer 184.

  On the other hand, as shown in FIG. 3, in the pressure roll 80 having the above-described configuration in the present invention, a semi-foamed heat-resistant resin for reinforcement is formed on the surface of the core metal 82 as the base material. Since the semi-foamed heat-resistant resin for reinforcement exerts an anchor effect, at the interface between the core metal 82 of the pressure roll 80 and the elastic layer 84. It is presumed that the limit load at which breakage occurs is greatly improved and the durability of the pressure roll 80 is improved.

  Here, in the above-described embodiment, the example in which the paper P is applied as the recording medium has been described. However, the recording medium referred to in the present embodiment is not limited to the paper, and sheets for various purposes are used. Further, the number of sheets may be one, or a plurality of sheets as in the case of producing a laminate sheet.

  In the embodiment described above, the IH heating method is shown as an example of the fixing device. However, the fixing device referred to in the present embodiment is not limited to this. For example, a heating method using a halogen lamp or a resistance heating element is used. You may employ | adopt.

<Method for Manufacturing Fixing Pressure Member>
A method of manufacturing a pressure roll that is a fixing pressure member in the present embodiment will be described with reference to FIG. In addition, it cannot be overemphasized that a manufacturing method is not restricted to this, It modifies suitably.

  For example, first, after adding a foaming agent to a liquid heat-resistant resin 87 dissolved in an organic solvent or the like and taking in air bubbles by stirring, the surface of the cylindrical metal core 82 is applied by various known methods. The cored bar 82 is heated or depressurized in a rotating state to foam the foaming agent or expand the bubbles to foam, remove the organic solvent, and further calcinate at a higher temperature if necessary. A foamed heat-resistant resin layer communicating with the outer peripheral surface of 82 is formed. Or it replaces with the above-mentioned heat resistant resin 87, and it is also possible to use the commercially available heat resistant resin varnish etc. with a self-foaming property.

  Alternatively, a liquid heat-resistant resin dissolved in an organic solvent or the like is applied to the outer peripheral surface of the cylindrical cored bar 12 and further dried to form a semi-dry film, which is then machined into the semi-dry film Along with the axial direction, it is turned up in parallel or spirally leaving a part of the adhesion part, and after standing up in a pleated form on the surface of the cored bar, it is further baked at a high temperature to bond the outer surface of the cored bar and protrude The heat resistant resin layer formed is formed.

  Alternatively, an adhesive is applied to the outer peripheral surface of the cylindrical metal core 12, and a strip-shaped heat-resistant resin film or a fibrous heat-resistant resin is used as a moisture-curing silicone adhesive, an addition-curing silicone adhesive, A heat-resistant resin layer is formed on the outer peripheral surface of the metal core by bonding with a fluorine rubber adhesive or an epoxy adhesive.

  Alternatively, an adhesive is applied to the outer peripheral surface of the cylindrical cored bar 12 and a sheet of a predetermined thickness is cut out from a heat-resistant resin block that has already been foamed and marketed, or wound into a tube shape The foamed heat-resistant resin layer communicated with the outer peripheral surface of the core metal is formed by inserting or fixing to the outer peripheral surface of the core metal.

  Next, a releasable resin tube 86 constituting a release layer 86 is inserted along the inner surface of a cylindrical metal mold 200 made of metal, and further, heat resistance having the above-described reinforcing effect (anchor effect) is provided inside the tube. The core metal 82 formed with the conductive resin is inserted, and the upper plug 204 and the lower plug 202 are fitted into the upper and lower portions of the mold 200 and held concentrically. Next, a liquid elastomer 85 containing hollow particles or the like is injected into the gap between the cored bar 82 and the releasable resin tube 86 and vulcanized, and then cooled to room temperature. 202 is removed, the core layer 82 with an elastic layer 84 and a release layer 86 made of a release resin tube is pulled out of the cylindrical mold, and the end of the roll is shaped. A pressure roll is produced by performing the above.

Alternatively, after the emulsion composition for forming a silicone rubber foam is applied to the surface of the cored bar 82 on which the heat-resistant resin having the reinforcing effect (anchor effect) described above is formed by flow coating, dip coating, or the like, in a rotating state. After heating and foaming to form the elastic layer 84, the outer peripheral surface of the roll is made into a predetermined roll shape and outer diameter by grinding as necessary, and then an adhesive is applied to the roll surface. Insert the releasable resin tube along the inner surface of the cylindrical shape made of a metal tube whose inner diameter is larger than the outer diameter of the roll, expand the releasable resin tube by vacuum suction, and then insert the roll and then vacuum After releasing the cover and covering the surface of the roll with a releasable tube, the end of the roll is shaped, and then the pressure roll is obtained by heat bonding and post-curing as necessary. It is manufactured. Alternatively, the release layer 86 may be formed by applying a fluorine resin dispersion by flow coating, dip coating, spray coating, or the like instead of the release tube, and further melting the fluorine resin by heating and baking.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not restrict | limited to a following example. The evaluations described in the following production examples, examples and comparative examples were carried out by the following methods.

[Example 1]
The results of the performance evaluation test of the fixing device configured as described above are shown below. Note that the fixing pressure member, the fixing device, and the image forming apparatus according to the present embodiment are not limited to the following modes.

  A 18-mm diameter columnar core made of nickel-plated iron is flow-coated with a polyamic acid solution (viscosity 160 Pa · s) having a solid content of 18% by mass of NMP as a solvent on the core bar to a thickness of 200 μm. After drying at 100 ° C. for 30 minutes, a part of the semi-dry film is spirally (spiral pitch 3.5 mm) along the axial direction of the cored bar by machining to have a height of about perpendicular to the surface of the cored bar. The sheet was rolled up into a 2.5 mm pleat shape, further heated to 360 ° C., and a reinforcing layer was formed toward the outer peripheral surface made of a polyimide resin having a thickness of about 2 mm in a cored bar shape. Furthermore, an equal amount mixed solution of primer 101A / B manufactured by Shin-Etsu Chemical Co., Ltd. was applied to spray coating.

  Next, after inserting a conductive PFA tube whose inner diameter of 30 μm was used with an inner diameter of 28 mm and sodium-naphthalene treatment, an equal volume of primer 101A / B made by Koshi Chemical Co., Ltd. Application was performed. Next, LSR (Shin-Etsu Chemical Co., Ltd. silicone rubber X34-1053A / B equivalent liquid mixture) containing 20% by mass of hollow glass beads (Sumitomo 3M, K20) with an average particle size of about 60 μm is injected. First vulcanized at 150 ° C., removed from the mold after cooling, shaped the end of the roll, and further vulcanized at 200 ° C. for 3 hours to obtain a pressure roll.

[Comparative Example 1]
Further, as shown in FIG. 4, the pressure roll of Comparative Example 1 was the same as that of Example 1 except that there was no reinforcing layer made of polyimide formed on the outer peripheral surface of the cored bar.

<Evaluation method>
In the test, the fixing roll shown in FIG. 3 is used to fix the pressure roll shown in FIG. 3 at a load of 0.45 MPa at a load higher than that, usually about 0.25 MPa. Pressed against the belt. 3 according to the present embodiment and the fixing device equipped with the pressure roll of Comparative Example 1, the peripheral speed of each pressure roll is 80 mm / s, and the control temperature of the heating roll. It was continuously rotated at 175 ° C.

  As a result, when the pressure member of Comparative Example 1 was used, rubber breakage occurred at an equivalent of about 60,000 sheets. On the other hand, when the pressure roll of this embodiment was used, it was equivalent to 100,000 sheets and no breakage occurred at the end.

[Example 2]
A thermal expansion microcapsule (manufactured by Matsumoto Yushi Seiyaku Co., Ltd. No. FN-100S) was added and mixed with stirring and flow-mixed in a cored bar shape with a thickness of 180 μm. After heating and drying at 80 ° C., the temperature was raised to 380 ° C. A semi-foamed reinforcing layer connected to the outer peripheral surface made of 2.5 mm polyimide resin was formed. Furthermore, an equal amount mixed solution of primer 101A / B manufactured by Shin-Etsu Chemical Co., Ltd. was applied by spray coating. Other than that, a pressure roll was produced according to Example 1.

  When the pressure roll of Example 2 was continuously rotated and driven under the same conditions as in Example 1 and Comparative Example 1, the pressure roll of Example 2 was equivalent to 100,000 sheets and fractured at the end. I didn't.

[Example 3]
A sponge sheet cut to 2.5 mm in thickness and 20 mm in width from a commercially available polyimide sponge (model number BF303, manufactured by Ube Industries, Ltd.) is attached to an 18 mm diameter columnar core made of iron plated with nickel by an adhesive. A polyimide sponge layer having a thickness of about 2.5 mm was formed on the core bar in a spiral shape around the core bar. Furthermore, an equal amount mixed solution of primer 101A / B manufactured by Shin-Etsu Chemical Co., Ltd. was applied to spray coating. Other than that, a pressure roll was produced according to Example 1 (corresponding to FIG. 7).

  The pressure roll of Example 3 was continuously rotated under the same conditions as in Examples 1 and 2 and Comparative Example 1. As a result, the pressure roll of Example 3 was equivalent to 100,000 sheets and no breakage occurred at the end.

[Example 4]
A short fiber-shaped polyimide resin cut out from a polyimide film with a thickness of 25 μm to a width of about 50 μm and a length of about 50 mm from a nickel-plated iron columnar core with an adhesive by an adhesive. The polyimide short fibers were pasted around the cored bar. The polyimide fiber is spring-shaped or wavy, and a part of the short fiber is fixed to the surface of the core metal with an adhesive, and after bonding, the polyimide fiber is formed with a gap on the core metal, and has a thickness of about 2. A 5 mm non-woven reinforcing layer was formed. Furthermore, an equal amount mixed solution of primer 101A / B manufactured by Shin-Etsu Chemical Co., Ltd. was applied by spray coating. Other than that, a pressure roll was produced according to Example 1.

  The pressure roll of Example 4 was continuously rotated under the same conditions as in Examples 1 to 3 and Comparative Example 1. As a result, the pressure roll of Example 4 was equivalent to 100,000 sheets and no breakage occurred at the end.

[Example 5]
A polyamic acid solution (initial viscosity 160 Pa · s) having a solid content of 18% by mass using NMP as a solvent is heated at 70 ° C. for 48 hours, and the imidization reaction proceeds to change the polyamic acid solution into a non-flowing gel state. After filling the gelled polyamic acid solution into a cylinder having a plurality of nozzles having a predetermined cross-sectional diameter of about 0.3 mm at the tip, a piston for extrusion is attached, and the polyamic acid in the cylinder is fitted. The acid is continuously extruded at a constant speed from a plurality of nozzles at a constant speed by a pressure applied by mechanical movement of the piston, and at the same time, a cylindrical cored bar made of nickel-plated iron and having a diameter of 18 mm is rotated and moved. However, a fibrous polyamic acid layer is coated over the entire outer peripheral surface of the cored bar, and further this is kept at 120 ° C. while rotating. The temperature was raised to 380 ° C. After heat dried to form a reinforcing layer having a thickness of about 2.5mm of fibrous polyimide resin on the metal core. Furthermore, an equal amount mixed solution of primer 101A / B manufactured by Shin-Etsu Chemical Co., Ltd. was applied by spray coating. Other than that, a pressure roll was produced according to Example 1 (corresponding to FIG. 8).

  The pressure roll of Example 5 was continuously rotated and driven under the same conditions as in Examples 1 to 4 and Comparative Example 1. As a result, the pressure roll of Example 5 was equivalent to 100,000 sheets and no breakage occurred at the end.

  As an application example of the present invention, there is application to an image forming apparatus such as a copying machine or a printer using an electrophotographic system.

  1Y, 1M, 1C, 1K Image forming unit, 10 Primary transfer unit, 11 Photosensitive drum, 12 Charger, 13 Laser exposure unit, 14 Developer, 15 Intermediate transfer belt, 16 Primary transfer roll, 17 Drum cleaner, 20 2 Next transfer section, 22 Secondary transfer roll, 25 Backup roll, 26 Feed roll, 31 Drive roll, 32 Support roll, 33 Tension roll, 34 Cleaning backup roll, 35 Intermediate transfer belt cleaner, 40 Control section, 43 Image density sensor, DESCRIPTION OF SYMBOLS 50 Recording medium accommodating part, 51 Pickup roll, 52 Conveyance roll, 53 Conveyance chute, 55 Conveyance belt, 56 Fixing inlet guide, 60 Magnetic field generator, 62 Excitation coil, 63 Magnetic core, 64 Excitation circuit, 66 Excitation coil holding member, 70 Heat-fixing belt, 7 2 pressure pad, 74 holder, 80 pressure roll, 82 core metal, 84 elastic layer, 86 release layer (release resin tube), 87 liquid heat resistant resin, 88 reinforcement layer, 90 fixing device, 100 image formation Apparatus, 180 pressure roll, 182 core, 184 elastic layer, 200 mold, 202 lower plug, 204 upper plug.

Claims (4)

A cylindrical substrate;
A heat-resistant elastomer containing hollow heat-resistant particles laminated on the cylindrical base material, or an elastic layer of a heat-resistant elastomer made of a foam having communication holes;
A release layer made of a heat-resistant resin having releasability in the outermost layer,
A fixing pressure member, characterized in that a semi-foamed reinforcing heat-resistant resin is bonded to the surface of the base material, and the reinforcing heat-resistant resin is embedded in the elastic layer.   The fixing pressure member according to claim 1, wherein the heat-resistant elastomer is silicone rubber, and the semi-foaming heat-resistant resin bonded to the surface of the base material is polyimide. A fixing pressure member according to claim 1 or 2,
A heating device;
Heated by the heating device, pressed against the fixing pressure member to form a contact area with the fixing pressure member, and a recording medium having a toner image formed on the surface sandwiched between the contact areas A heating and fixing member for fixing the toner image by heating and pressurizing while moving around, and
A fixing device. Latent image forming means for forming a latent image on the image carrier;
Developing means for developing the latent image using a developer for developing an electrostatic image;
An image forming apparatus comprising: a transfer unit that transfers a developed toner image onto a transfer target member with or without an intermediate transfer member; and a fixing unit that fixes the toner image on the transfer target member. An image forming apparatus, wherein the fixing unit includes the fixing device according to claim 3.

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