JP6004893B2 - Tube coating method on substrate - Google Patents

Description

The present invention relates to a tube coated how for tubular or cylindrical substrates.

Here, the fixing member is a pressure member serving as a pressing means for forming a heating member or heating member and the fixing nip, as a heating means for heating the contact with the image on the image bearing surface of the recording material, or both It is.

  Conventionally, for example, a silicone rubber layer is formed on the surface of a metal core as a roll used as a fixing member in an image heating and fixing apparatus mounted on an image forming apparatus such as an electrophotographic copying machine, a printer, or a facsimile. And what used the fluororesin tube on the surface further is used.

  As a method of coating the roller or belt of the fixing device with resin, a method of coating a resin tube on the roller or belt surface is generally used.

  As a method for producing a fixing roller (heating roller or pressure roller) coated with a tube, a PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) tube is conventionally fixed to the inner peripheral surface of a mold. Next, a method has been proposed in which a core metal is inserted into a mold, and then silicone rubber is injected and cured between the core metal and the PFA tube so as to be integrally formed (Patent Document 1).

  However, in the tube coating method using the mold as described above, if the center axis of the roll and the center axis of the inner peripheral surface of the mold do not exactly match, the cylindricity after manufacture shifts and is fixed during use. This is not preferable because a roller swinging phenomenon occurs.

  In this way, in order to make the runout of the fixing roller within a predetermined range, the center axis of the roll and the center axis of the inner peripheral surface of the mold must be matched with high accuracy, and a mold with high shape accuracy is required. There is a problem that the manufacturing cost becomes expensive.

  In recent years, one end of a PFA tube is suspended and held in a decompression vessel as a method for covering the rubber roller with a tube at a low cost by a simple process without using such a high-precision mold. Then, while sucking the gas in the decompression container from the other end, a rubber roller having an outer diameter slightly larger than the inner diameter of the PFA tube and coated with an adhesive is inserted. Thereafter, a method of curing the adhesive has been proposed (Patent Document 2).

  However, when the adhesive applied to the outer peripheral surface of the rubber roller is inserted into the tube, the adhesive is moved in the insertion direction along with the tube. For this reason, there is a bias in the axial direction of the roller, or the adhesive on the roller outer peripheral surface partially loses liquid, causing poor adhesion.

  As a tube covering method for preventing such uneven thickness of the adhesive layer, an adhesive is applied to the outer peripheral surface of the inserted body. Then, a fluororesin tube having elasticity at least along the radial direction is tightly covered. Thereafter, a handling ring having a diameter smaller than the outer diameter of the inserted body is fitted to one end of the outer periphery of the fluororesin tube covered on the outer periphery of the inserted body. A method has been proposed in which the handling ring is moved toward the other end along the axial direction of the inserted body to handle the adhesive between the inserted body and the fluororesin tube (Patent Document 3). ).

  However, since the fluororesin tube is handled while being rubbed with a handling ring having a diameter smaller than the outer diameter of the inserted body, the sliding friction between the fluororesin tube and the handling ring is large. For this reason, the tube has been stretched or a lubricant such as oil has been required to reduce friction. If a lubricant is used, the surroundings may be contaminated and cause adhesion failure due to adhesion to the base material, or a process of wiping off the lubricant on the surface after processing is required.

  In order to solve these problems, the following method is used in a tube coating method in which a member coated with a tube is obtained by interposing an adhesive between a cylindrical or columnar base material and the tube and curing the adhesive. Is proposed in Patent Document 4.

  That is, a ring-shaped member slightly larger than the member covered with the tube is externally fitted in an uncured state in which the adhesive interposed between the base material and the tube is liquid or pasty. Then, the ring-shaped member is moved in the axial direction of the tube while air is ejected from the ring-shaped member to the tube surface in a direction perpendicular to the axial direction of the tube. This is a method of coating a tube on a base material, including an extra adhesive handling step between the base material and the tube, characterized in that the adhesive agent interposed between the base material and the tube is handled.

JP-A-63-298383 Japanese Patent Publication No. 8-15758 JP 2002-36361 A JP 2005-238765 A

  However, since this method uses jet air, the handling ability decreases as the distance to the object increases. The distance from the object is relatively small, and it is necessary to perform an advanced position adjustment or to use a centering action by the blown air. In any case, there was a case where the PFA tube was damaged by contact.

The present invention relates to a further improvement of the technique of Patent Document 4. The main object of the present invention is to provide a tube coating method that does not damage the tube when the tube is coated with an adhesive on a base material such as a rubber roller or a belt, when the tube is handled with blown air. Ru der to provide.

The typical configuration of the tube coating method according to the present invention for achieving the above object is as follows:
In a tube coating method for obtaining a member coated with the tube by interposing an adhesive between a cylindrical or columnar base material and a tube covering the outside of the base material, and curing the adhesive,
An extension step of extending the tube in the longitudinal direction after covering the tube with the base material in an uncured state where the adhesive is liquid or pasty ;
A fixing step of fixing one end side and the other end side of the tube in the longitudinal direction to the base material while maintaining extension in the longitudinal direction of the tube;
A handling step of handling the outer surface of the tube after the fixing step and handling excess adhesive between the substrate and the tube ;
A curing step of curing the adhesive after the handling step ,
In the handling step, a ring-shaped member having a slightly larger diameter than that of the member is externally fitted to the member covered with the tube, and then air is supplied from the ring-shaped member to the surface of the tube. At least the innermost diameter portion of the ring-shaped member, the step of handling the adhesive interposed between the base material and the tube by being moved in the axial direction while being jetted in a direction intersecting the axial direction A tube coating method characterized by using a material having a hardness equal to or less than that of the tube.

  According to the present invention, it is possible to provide a tube coating method that does not damage a tube when the tube is coated with an adhesive interposed in the base material when the tube is handled with blown air.

The figure for demonstrating the handling process by a ring-shaped member It is a figure explaining the method of coat | covering the PFA tube of a fixing belt (or pressure belt). The figure for demonstrating the structure of a fixing belt (or pressure belt) Diagram for explaining an example of an image forming apparatus The figure for demonstrating the fixing device of an Example. Illustration for explaining the ring coat Diagram for explaining a conventional handling ring The figure for demonstrating the handling ring of Example 1. The figure for demonstrating the handling ring of Example 2.

  Hereinafter, the present invention will be described more specifically with reference to examples. Although these examples are examples of embodiments to which the present invention can be applied, the present invention is not limited to these examples, and various modifications are possible within the scope of the idea of the present invention.

[Example]
(1) Image Forming Unit FIG. 3 is a schematic configuration schematic diagram of the image forming apparatus used in this embodiment. The image forming apparatus 1 is an electrophotographic laser printer, and includes a photosensitive drum 2 as an image carrier for carrying a latent image. The photosensitive drum 2 is rotationally driven in a clockwise direction indicated by an arrow at a predetermined speed, and its outer surface is uniformly charged to a predetermined polarity and potential by the charger 3. Laser scanning exposure 5 of image information is performed on the uniformly charged surface by a laser scanner (optical device) 4. As a result, an electrostatic latent image of the scanned image information is formed on the surface of the photosensitive drum 2.

  The electrostatic latent image is developed as a toner image by the developing device 6. The toner images are sequentially transferred to the recording material (sheet) S introduced into the transfer portion at the transfer portion which is a contact portion between the photosensitive drum 2 and the transfer roller 7.

The recording material S is stacked and stored in a feeding cassette 9 at the lower part of the apparatus. When the roller 10 feeding at a predetermined feed timing is driven, is a recording material feeding cassette 9 is fed one sheet separated and fed, reaches the registration roller pair 11 through the conveyance path 10a. The registration roller pair 11 receives the leading end of the recording material S and corrects the skew of the recording material. Further, in synchronization with the toner image on the photosensitive drum, the timing of the leading edge of the recording material just reaches the transfer portion when the leading edge of the toner image on the photosensitive drum reaches the transfer portion. The recording material S is fed to the transfer unit.

  The recording material S that has passed through the transfer portion is separated from the surface of the photosensitive drum 2 and conveyed to the image fixing device A. The fixing device A fixes an unfixed toner image on the recording material S as a fixed image on the recording material surface by heating and pressing. Then, the recording material is discharged and stacked on the discharge tray 13 at the upper part of the apparatus by the discharge roller pair 12 through the conveyance path 10b. Further, the surface of the photosensitive drum 2 after separation of the recording material is cleaned by removing residual deposits such as transfer residual toner by the cleaning device 8 and repeatedly used for image formation.

(2) Fixing device A
FIG. 4 is a schematic structural diagram of an image heating and fixing apparatus A in this embodiment. The fixing device A is a twin belt type-electromagnetic induction heating type device.

Here, the longitudinal direction or the longitudinal direction of the fixing device A or a member constituting the fixing device A is a direction parallel to a direction orthogonal to the recording material conveyance direction in the recording material conveyance path surface. The front of the fixing device is the surface on the recording material introduction side. Left and right are left or right when the device is viewed from the front. The belt width is a belt dimension (= dimension in the belt longitudinal direction) in a direction orthogonal to the recording material conveyance direction. The width of the recording material is a recording material dimension in a direction orthogonal to the recording material conveyance direction on the recording material surface. Further, upstream or downstream is upstream or downstream in the recording material conveyance direction.

  The fixing device A is a fixing member for an image heating and fixing device. The fixing belt 20 as a heating member that forms a fixing nip that fixes and fixes an image by sandwiching and conveying the recording material while being pressed against each other. A pressure belt 30 is provided. Both the fixing belt 20 and the pressure belt 30 are flexible endless belts.

The configuration of the fixing belt 20 will be described in detail in section (3). The fixing belt 20 includes a tension roller 51 and a fixing roller 52 arranged in parallel with a gap as a belt suspension member, and a downward pressure as a first pressure pad disposed between the rollers 51 and 52. It is stretched around the fixing pad 53. The tension roller 51 and the fixing roller 52 are supported by being rotatably supported between left and right side plates of a fixing device casing (not shown). The fixing pad 53 is supported and disposed between the left and right side plates of the fixing device casing.

  The tension roller 51 is an iron hollow roller having a thickness of 1 mm and an outer diameter of 20 mm and an inner diameter of 18 mm, and gives tension to the fixing belt 20.

  The fixing roller 52 is a highly slidable elastic roller in which an iron alloy hollow core metal having an outer diameter of 20 mm and an inner diameter of 18 mm is provided with a silicone rubber elastic layer as an elastic layer. The fixing roller 52 receives a driving force from a driving source (motor) M via a driving gear train (not shown) as a driving roller, and is rotationally driven in a clockwise direction indicated by an arrow at a predetermined speed.

  By providing the elastic layer on the fixing roller 52 as described above, the driving force input to the fixing roller 52 can be transmitted to the fixing belt 20 and the recording material S can be separated from the fixing belt 20. It is possible to form a fixing nip for ensuring the above. The hardness of silicone rubber is JIS-A 15 degrees. The silicone rubber elastic layer reduces heat conduction to the inside, and is effective in shortening the warm-up time.

In this embodiment, the pressurizing belt 30 has electrocast nickel as a base layer, and the surface is provided with a PFA tube of fluororesin with a thickness of 30 μm as a release layer. The pressure belt 30 is disposed below the fixing belt 20 in the drawing as follows. That is, the pressure belt 30 includes a tension roller 54 and a pressure roller 55 arranged in parallel with a gap as a belt suspension member, and a second pressure pad disposed between the rollers 54 and 55. Between the pressure pad 56 and the upward pressure pad 56.

  The tension roller 54 and the pressure roller 55 are rotatably supported and supported between left and right side plates of a fixing device casing (not shown). The tension roller 54 is a silicone sponge for reducing the heat conductivity from the pressure belt 30 by reducing the heat conductivity to a hollow core metal made of iron alloy having an outer diameter of 20 mm and an inner diameter of 16 mm and a thickness of 2 mm. A layer is provided to tension the pressure belt 30. The pressure roller 55 is a low-sliding hollow rigid roller made of an iron alloy having an outer diameter of 20 mm and an inner diameter of 16 mm and a thickness of 2 mm. The pressure pad 56 is supported and disposed between the left and right side plates of the fixing device casing.

  In order to form a fixing nip 60 as an image heating unit between the fixing belt 20 and the pressure belt 30, the pressure roller 55 has arrows on the left and right ends of the rotation shaft respectively by a pressure mechanism (not shown). Pressure is applied toward the fixing roller 52 with a predetermined pressure in the direction F.

  In order to obtain a wide fixing nip 60 without increasing the size of the apparatus, a pressure pad is employed. That is, the fixing belt 53 is pressed toward the pressure belt 30 by the fixing pad 53 and the pressure belt 30 is pressed toward the fixing belt 20 by the pressure pad 56. The pressure pad 56 is pressed toward the fixing pad 53 with a predetermined pressure in the direction of arrow G by a pressure mechanism (not shown). By fixing the fixing belt 20 and the pressure belt 30 between the fixing pad 53 and the pressure pad 56, a wide fixing nip 60 is formed in the recording material conveyance direction.

  The fixing pad 53 has a sliding sheet (low friction sheet) 58 in contact with the pad base and the inner surface of the fixing belt. The pressure pad 56 also has a sliding sheet 59 in contact with the pad base and the inner surface of the pressure belt. This is because when the belt base layer is made of a metal layer, there is a problem that the portion of the pad that slides on the inner peripheral surface of the pad is greatly scraped. By interposing the sliding sheets 58 and 59 between the belt and the pad base, the pad can be prevented from being scraped and the sliding resistance can be reduced, so that good belt running performance and belt durability can be secured.

  As a heating means for the fixing belt 20, a heat source (induction heating member, excitation coil) of an electromagnetic induction heating method with high energy efficiency is employed. The induction heating member 57 as a heating source is disposed to face the outer surface of the ascending belt portion of the fixing belt 20 with a predetermined slight gap.

  The induction heating member 57 includes an induction coil 57a, an excitation core 57b, and a coil holder 57c that holds them. The induction coil 57a uses a litz wire flattened in an oval shape, and is disposed in a lateral E-type excitation core 57b protruding from the center and both sides of the induction coil. Since the exciting core 57b is made of ferrite or permalloy having a high magnetic permeability and a low residual magnetic velocity density, loss in the induction coil 57a and the exciting core 57b can be suppressed and the fixing belt 20 can be efficiently heated.

  The fixing operation is as follows. The control circuit unit 63 drives the motor M at least during execution of image formation. Further, a high frequency current is passed from the excitation circuit 64 to the induction coil 57 a of the induction heating member 57.

  By driving the motor M, the fixing roller 52 is rotationally driven. As a result, the fixing belt 20 is rotationally driven in the same direction as the fixing roller 52. The circumferential speed of the fixing belt 20 is slightly lower than the conveyance speed of the sheet S conveyed from the image forming unit side in order to form a loop in the recording material S on the recording material entrance side of the fixing nip 60. Has been. In this embodiment, the peripheral speed of the fixing belt 20 is 300 mm / sec, and it is possible to fix 70 A4 size full color images per minute.

  The pressure belt 30 rotates following the fixing belt 20 by the frictional force with the fixing belt 20 in the fixing nip 60. Here, the belt downstream can be prevented from slipping by adopting a configuration in which the fixing belt 20 and the pressure belt 30 are sandwiched and conveyed by the roller pair 52/55 at the most downstream portion of the fixing nip. The most downstream portion of the fixing nip is a portion where the pressure distribution (recording material conveyance direction) at the fixing nip is maximized.

  On the other hand, when a high frequency current flows from the excitation circuit 54 to the induction coil 57a of the induction heating member 57, the metal layer of the fixing belt 20 is inductively heated and the fixing belt 20 is heated. The surface temperature of the fixing belt 20 is detected by a temperature detection element 62 such as a thermistor. A signal related to the temperature of the fixing belt 20 detected by the temperature detection element 62 is input to the control circuit unit 63. The control circuit unit 63 controls the power supplied from the excitation circuit 64 to the induction coil 57a so that the temperature information input from the temperature detecting element 62 is maintained at a predetermined fixing temperature, thereby setting the temperature of the fixing belt 20 to a predetermined fixing temperature. Adjust temperature to temperature.

  The recording material S having the unfixed toner image t is conveyed to the fixing nip 60 between the fixing belt 20 and the pressure belt 30 in a state where the fixing belt 20 is rotationally driven and the temperature is adjusted by rising to a predetermined fixing temperature. Is done. The recording material S is introduced with the surface carrying the unfixed toner image t facing the fixing belt 20 side. The recording material S is nipped and conveyed by the fixing nip 60 while the unfixed toner image carrying surface is in close contact with the outer peripheral surface of the fixing belt 20, so that heat is applied from the fixing belt 20 and pressure is applied. The unfixed toner image t is fixed on the surface of the recording material S.

  Further, since the fixing roller 32 in the fixing belt 20 is an elastic roller having a rubber layer, and the pressure roller 35 in the pressure belt 30 is an iron alloy rigid roller, the fixing belt 20, the pressure belt 30, The deformation of the fixing roller 52 is large at the fixing nip exit. As a result, the fixing belt 20 is also greatly deformed, and the recording material S carrying the fixing toner image is separated from the fixing belt 20 by the curvature thereof. 61 is a separation auxiliary claw member.

(3) Fixing belt 20
2A is a schematic cross-sectional view showing a layer structure of the fixing belt 20 as a fixing member in this embodiment, and FIG. 21 is a base material (cylindrical base) of the fixing belt 20, 25 is an inner surface sliding layer disposed on the inner peripheral surface of the base body 21, 26 is a primer layer covering the outer peripheral surface of the base material 21, and 22 is a primer layer. 26 is an elastic layer (cylindrical elastic layer) disposed on the surface 26. Reference numeral 24 denotes a fluororesin tube as a surface layer, which is fixed to the peripheral surface of the elastic layer 22 by an adhesive layer 23.

  The fixing belt 20 of the present embodiment is the above-described six-layer laminated composite layer member, which is a thin, low-heat capacity member having flexibility as a whole. The fixing belt 20 has a substantially cylindrical shape in a free state. Each constituent layer will be specifically described below.

(3-1) Substrate 21
In this embodiment, the base material 21 of the fixing belt 20 is formed of a metal layer such as SUS alloy, nickel, iron, magnetic stainless steel, cobalt-nickel alloy, etc. in order to be heated by the induction heating member 57. In this embodiment, an electroformed nickel belt having an inner diameter of 55 mm and a thickness of 65 μm is used as a base material.

  The thickness is preferably 1 to 300 μm. If the thickness of the substrate 21 is smaller than 1 μm, the rigidity is low and it is difficult to endure the durability of a large number of sheets. On the other hand, if the substrate 21 exceeds 300 μm, the rigidity becomes too high and the flexibility is lowered, which is not practical for use as a belt-like rotating body. More preferably, 20 μm to 100 μm is ideal.

(3-2) Inner surface sliding layer 25
As the inner surface sliding layer 25, a resin having high durability and high heat resistance such as polyimide resin is suitable. In this example, a polyimide precursor solution obtained by reacting approximately equimolar amounts of an aromatic tetracarboxylic dianhydride or its derivative and an aromatic diamine in an organic polar solvent is applied to the inner surface of the substrate 21. Work. And it dried and heated, the polyimide resin layer formed by the dehydration ring closure reaction was formed, and it was set as the inner surface sliding layer 25. FIG.

(3-3) Primer layer 26
The primer layer 26 is provided between the base material 21 and the elastic layer 22 and helps both the base material 21 and the elastic layer 22 adhere. Examples of the material include hydrosilyl type (SiH type), silicone primer, vinyl type silicone primer, alkoxy type silicone primer and the like. The silicone rubber elastic layer and the base material layer are bonded to each other by addition polymerization crosslinking in the hydrosilyl type and condensation polymerization crosslinking in the alkoxy type. Examples of the forming method include coating formation by dipping, spraying, brushing, and the like.

  In this example, a method in which a hydrosilyl primer appropriately diluted with a solvent was applied with a sponge pad.

(3-4) Elastic layer 22
An elastic layer 22 is provided on the outer periphery of the substrate 21 via a primer layer 26. As the material of the elastic layer 22, a known elastic material can be used, and for example, silicone rubber, fluorine rubber, or the like can be used.

  The thickness of the elastic layer 22 is preferably 100 μm or more in order to prevent uneven gloss due to the fact that the heating surface of the fixing belt cannot follow the unevenness of the recording material S or the unevenness of the toner layer when printing an image.

  If the thickness of the elastic layer 22 is less than 100 μm, the function as an elastic member is not exhibited, and the pressure distribution at the time of fixing becomes non-uniform, thereby sufficiently heating the unfixed toner of the secondary color particularly at the time of fixing a full color image. Unable to fix, unevenness occurs in the gloss of the fixed image. Insufficient melting lowers the color mixing property of the toner and is not preferable because a high-definition full-color image cannot be obtained. In this embodiment, silicone rubber is used, the hardness is JIS-A 6 degrees, the thermal conductivity is 0.8 W / mK, and the thickness is 450 μm.

  A method for applying the elastic layer 22 will be described with reference to FIG. FIG. 5 is an example of a process for forming a silicone rubber layer as the elastic layer 22 on the substrate 21, and is a schematic diagram for explaining a method using a so-called ring coating method.

  In this embodiment, the cylinder pump 41 is filled with an addition-curable silicone rubber composition in which an addition-curable silicone rubber and a filler are blended. Then, the above-described composition is pumped from the cylinder pump 41 to the annular coating head 42 to thereby form a cylindrical substrate 21 (25) from a coating liquid supply nozzle (not shown) arranged inside the annular coating head 42. The addition curable silicone rubber composition is applied to the peripheral surfaces of 21 and 26). The peripheral surface of the cylindrical base 21 is previously primed by a known method.

  The coating head 42 is held by a fixed coating head holding portion 43. The cylinder pump 41 is driven by the motor M <b> 1 to pump the addition-curable silicone rubber composition to the coating head 43 through the tube 44.

  The cylindrical base body 21 is externally fitted to and held by a cylindrical core metal held by a metal core holder 45. The cored bar holder 45 is held on the coating table 46 so as to be horizontally movable with the axis thereof being horizontal. The annular coating head 42 is fitted on the cylindrical base body 21 coaxially. The coating table 46 is moved forward at a predetermined speed in the horizontal axis direction of the cored bar holder 45 by the motor M2. Further, it is moved backward (returned).

  Simultaneously with the coating by the coating head 42, the cylindrical substrate 21 is moved (forwardly moved) in the right direction at a constant speed on the drawing, so that the coating film 22a of the addition-curing silicone rubber composition is formed around the cylindrical substrate 21. The surface can be formed in a cylindrical shape.

  The thickness of the coating film can be controlled by the clearance between the coating liquid supply nozzle and the cylindrical substrate 21, the supply speed of the silicone rubber composition, the moving speed of the cylindrical substrate 21, and the like.

  The addition-curable silicone rubber composition layer 22a formed on the cylindrical substrate 21 is heated for a certain period of time by a heating means such as an electric furnace to advance the crosslinking reaction, thereby forming the silicone rubber elastic layer 22. it can. In the examples, heating was performed at 200 ° C. for 30 minutes in an electric furnace.

(3-5) Adhesive layer 23
The adhesive layer 23 for fixing the fluorine tube on the cured silicone rubber layer which is the elastic layer 22 is made of a cured product of an addition-curable silicone rubber adhesive in which the thickness is uniformly applied to the surface of the elastic layer 22. The addition curable silicone rubber adhesive includes an addition curable silicone rubber in which a self-adhesive component is blended. Specifically, the addition-curable silicone rubber adhesive contains an organopolysiloxane having an unsaturated hydrocarbon group represented by a vinyl group, a hydrogen organopolysiloxane, and a platinum compound as a crosslinking catalyst. And it hardens | cures by addition reaction.

  As such an adhesive, a known adhesive can be used. The adhesive layer can be formed by the same method as the elastic layer. In this example, TSE3250 (manufactured by GE Toshiba Silicone) was uniformly applied with a thickness of about 6 μm.

(3-6) Surface layer 24
As the surface layer of the fixing member, a fluororesin tube 24 by extrusion molding is used from the viewpoint of moldability and toner releasability.

  As the fluororesin, a tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA) excellent in heat resistance is suitably used. A PFA tube is formed by extrusion. The form of copolymerization of PFA as a raw material is not particularly limited, and examples thereof include random copolymerization, block copolymerization, and graft copolymerization.

  Moreover, the content molar ratio of tetrafluoroethylene (TFE) and perfluoroalkyl vinyl ether (PAVE) in PFA as a raw material is not particularly limited. For example, a TFE / PAVE containing molar ratio of 94/6 to 99/1 can be suitably used.

  In addition, tetrafluoroethylene / hexafluoropropylene copolymer (FEP), polytetrafluoroethylene (PTFE), and ethylene / tetrafluoroethylene copolymer (ETFE) can be used. Polychlorotrifluoroethylene (PCTFE), ethylene / chlorotrifluoroethylene copolymer (ECTFE), polyvinylidene fluoride (PVDF), or the like can also be used. These fluororesins can be used alone or in combination.

  In this example, a PFA tube obtained by extrusion molding was used. The tube thickness was 40 μm. The inner diameter of the tube was smaller than the outer diameter of the elastic layer and was 52.2 mm. The inner surface of the tube is treated with ammonia in order to improve adhesion.

(3-7) Fluororesin tube coating method In this embodiment, the PFA tube 24 as a surface layer is expanded from the outside and covered (extended coating method: the cylindrical elastic layer 22 coated with the adhesive 23 on the fluororesin tube 24). The fluororesin tube covering step) is used. This extended coating method will be described with reference to FIG. 1B.

(A) Tube insertion A PFA tube 24 is placed inside a metal tube expansion type K having an inner diameter larger than the outer diameter of the base material W (FIG. 2B) on which a silicone rubber layer is laminated as the elastic layer 22 ( insert.

(B) Both Ends Holding Both ends of the PFA tube 24 arranged in the expansion type K are held using the holding members Fu and Fl.

(C) Shrinkage Next, the PFA tube 24 is shrunk in the longitudinal direction by a predetermined length determined in advance (shrinking step of shrinking in the longitudinal direction so as to be shorter than the entire length of the fluororesin tube).

(D) Vacuum expansion The gap between the outer surface of the PFA tube 24 and the inner surface of the expansion type K is brought into a vacuum state (negative pressure with respect to atmospheric pressure). The vacuum (5 kPa) causes the PFA tube 24 to expand and the outer surface of the PFA tube 24 comes into close contact with the inner surface of the expandable K.

(E) Inserting the base material W The base material W (25 + 21 + 26 + 22 + 23) is set (externally fitted) to the core N, and inserted into the expansion type K in which the PFA tube 24 is expanded inside. On the surface of the silicone rubber layer 22 of the substrate W, a liquid or paste-like uncured addition curable silicone rubber adhesive 23 is uniformly applied in advance.

  The inner diameter of the expansion type K is not particularly limited as long as the base material W can be smoothly inserted.

(F) Vacuum break After the base material W is disposed with respect to the expansion type K, the vacuum state (negative pressure with respect to atmospheric pressure) of the gap between the outer surface of the PFA tube 24 and the inner surface of the expansion type K is destroyed (with respect to atmospheric pressure). To release the negative pressure). When the vacuum is broken, the PFA tube 24 is undiametered to the same size as the outer diameter of the base material W on which the silicone rubber layer 22 is laminated (a loosening process for loosening the expansion of the fluororesin tube), and the PFA tube 24 24 and the surface of the silicone rubber layer are in close contact with each other.

(G) Stretching step Next, the PFA tube 24 is stretched to a predetermined stretch rate (stretching step in the longitudinal direction of the fluororesin tube).

  When the PFA tube 24 is stretched, the addition-curing silicone rubber adhesive 23 between the PFA tube 24 and the silicone rubber layer 22 serves as a lubricant and can stretch smoothly.

(H) Caulking process In order to maintain the elongation ratio in the longitudinal direction of the PFA tube 24, both ends of the elastic layer 22 and the PFA tube 24 (parts to be cut in the subsequent process) are formed with caulking bits H1 with a built-in heater. It is a caulking process.

  That is, since the PFA tube shrinks due to elasticity and the elongation rate decreases when the adhesive is uncured, the elastic layer 22 is formed at both longitudinal ends of the belt for the purpose of maintaining the elongation rate in the longitudinal direction. And the PFA tube 24 are bonded. As a method, in this example, the metal lump H1 with a built-in heater was pressed against the belt surface and heated.

(I) Handling Process Excess (excess) addition-curing silicone rubber adhesive 23 that does not contribute to adhesion and air that has been engulfed during tube coating exist between the elastic layer 22 and the PFA tube 24. This is a process of handling excess adhesive and air.

  The base material W covered with the PFA tube 24 is taken out from the expansion type K. A ring-shaped member (a handling ring having a diameter slightly larger than the member (W + 24) covered with the tube 24) R having an inner diameter slightly larger than the outer diameter of the substrate W is externally fitted to the substrate W.

  Here, the slightly larger aperture means [0.1 mm ≦ (ring-shaped member inner diameter−outer diameter of substrate coated with tube) ≦ 2 mm], preferably [0.4 mm ≦ (ring-shaped member inner diameter−tube. The outer diameter of the coated substrate) ≦ 1 mm]. In addition, since the outer diameter of the base material W covering the tube is assumed to have a protruding portion or an oval shape, the average outer diameter is referred to as “the outer diameter of the base material covering the tube”. .

  Then, the ring-shaped member R is blown from the one side end of the base material W covered with the PFA tube 24 to the surface of the PFA tube 24 in a direction perpendicular to the circumferential direction of the PFA tube 24 (crossing direction). The PFA tube 24 is moved in the longitudinal direction.

  As a result, the excess addition-curing silicone rubber adhesive 23 that does not contribute to the adhesion between the elastic layer 22 and the PFA tube 24 and the air that has been engulfed when the tube is covered are handled (process for handling the applied adhesive). ).

  FIG. 1A is a schematic diagram of this handling process. In the present embodiment, a handling ring R (nozzle) that ejects air is used as handling means in the handling process. In FIG. 1A, 1 is a core material (same as the cylindrical core metal 21 or the core N), 3 is a vent, 4 is an air injection means, and 30 is an air generation means. The base material W is press-fitted and fixed to the core material 1, and air is blown out between the base material W and the core material by the vent 3, the air injection means 4, and the air generation means 30 at the time of press-fitting, so that the air is a lubricant. Press-fit as

  From one end of the base material W prepared by the steps (a) to (h), the handling ring R is a base material with the axis of the base material W and the axis of the handling ring R maintained concentric. Move in the axial direction of W. When the handling ring R comes to a predetermined position on the base material W, air is supplied to the handling ring R from a supply device (not shown). Air is ejected from the air ejection port 2c via the air supply port 2a and the air passage 2b of the handling ring R.

  The handling ring R handles the surplus of the adhesive 23 interposed between the base material W and the tube 24 by moving in the axial direction of the base material W while jetting air from the air jet outlet 2c. go. When the handling ring R comes to a predetermined position in the axial direction of the base material W, the ejection of air is stopped and the handling is completed.

  By this process, the excess of the adhesive 23 interposed between the base material W and the tube 24 is removed, and the thickness of the adhesive layer 23 is made uniform so that the base material W and the tube 24 are stably and strongly bonded. Is realized.

(J) Heat treatment After the handling step, the entire addition-curable silicone rubber adhesive 23 is cured (crosslinked) by performing a heat treatment (heating at 150 ° C. for 20 minutes in an electric furnace). Thereby, the PFA tube 24 and the elastic layer 22 are fixed over the entire region (step of curing the adhesive).

(K) Cutting and Polishing After the heat treatment, natural cooling was performed, and then both ends of the substrate W (25 + 21 + 26 + 22 + 23 + 24) were cut to a predetermined length and then polished to complete the fixing belt 20.

(4) Comparative Example FIG. 6 shows a handling ring R1 conventionally used by the present inventors as a comparative example. The symbols in the figure correspond to those in FIG. 1A. FIG. 6A shows a cross section of the handling ring R1. Air is supplied to the handling ring R1 from a supply device (not shown), and the air is ejected from the air ejection port 2c via the air supply port 2a and the air passage 2b. The handling ring R1 moves in the axial direction of the substrate W while ejecting air from the air ejection port 2c.

  The material of the handling ring R1 is SUS304 (stainless steel) in consideration of durability. FIG. 6B shows details of the air outlet 2c. The cross section of the base material W (including the belt holding member N) is shown in opposition to the air ejection port 2c. The pressure of air is proportional to the cross-sectional area of the gap according to the law of fluid mechanics, and the pressure decreases as the gap increases. That is, the handling ability is improved as the substrate surface and the nozzle are closer to each other. Although it depends on the outer diameter of the substrate, in this embodiment, at an air pressure of about 0.55 MPa, the difference between the inner diameter of the handling ring R1 and the outer diameter of the substrate W coated with the fluororesin tube 24 is 0.6 mm, It was necessary to make it about.

  Further, since the central axis of the handling ring R1 coincides with the central axis of the base material W, the handling ring R1 is used in a floating state at least in a plane orthogonal to the central axis of the base material by jetting air. did.

  Furthermore, since it is necessary to transport surplus adhesive etc. in the advancing direction of the handling ring R1, handling capability is required in the advancing direction. Therefore, the clearance is effectively handled by making the traveling direction wider and making the ejection direction the traveling direction.

  As described above, in order to handle, it is necessary to reduce the distance between the substrate W and the handling nozzle R1. It is also necessary to maintain the concentricity of the axis of the base material W and the axis of the handling ring R1. That is, there is a possibility that the tube 24 of the base material W and the handling ring R1 are in contact with each other, and in the study by the present inventors, damage to the tube 24 due to contact has become a problem.

(5) Example 1
In order to solve such a problem, the inventors of the conventional handling ring R <b> 1 make a portion that contacts the tube 24 (the innermost diameter portion of the handling ring) a material having a hardness equal to or less than that of the tube 24. And found that this can be reduced.

  The configuration of this embodiment will be described with reference to FIG. 7A is a cross-sectional view of the handling ring R, and FIG. 7B is a detailed view of the air outlet 2c. As indicated by 2d in FIG. 7B, the closest part of the handling ring R and the PFA tube (the innermost diameter part of the handling ring) is changed to a rubber member.

  As the material of the rubber member portion 2d, various resin materials can be used, but considering that the hardness (hardness equal to or less than that of the tube) is smaller than that of the PFA tube 24, a rubber material is preferable. Further, since the handling ring R needs to be cleaned with a solvent, in consideration of these, the present embodiment uses perfluoro fluororubber.

  However, the gist of the present invention is only required to be a material having a hardness lower than that of the PFA tube 24. For example, various rubber materials such as ethylene propylene rubber, silicon rubber, and fluorine rubber can be used. The inner diameter of the handling ring R including the rubber member 2d is slightly larger than the handling target, and the clearance between the PFA tube 24 and the handling ring R (the innermost diameter portion of the handling ring) is 0.2 mm to 0.5 mm. It was made to become.

(6) Example 2
Further, by using an O-ring as a part of the handling ring R, the gap between the base material W and the handling ring R can be made smaller, and the air can be handled more effectively by controlling the ejection of air. I found it.

  The configuration of this embodiment will be described with reference to FIG. 8A is a cross-sectional view of the handling ring, and FIG. 8B is a detailed view of the air ejection port 2c. Since the handle ring needs to be disassembled and cleaned with a solvent at the portion closest to the PFA tube 24 of the handle ring R (the innermost diameter portion of the handle ring), the O-ring 2d made of perfluoro fluororubber is taken into consideration. Arranged.

  The material of the O-ring 2d may be silicone resin, silicone rubber, or the like as long as the hardness is smaller than that of the PFA tube 24. The inner diameter of the handling ring R including the rubber member (O-ring) 2d (the innermost diameter portion of the handling ring) is slightly larger than the handling object, and the clearance between the PFA tube 24 and the handling ring R is 0.05 mm to 0 mm. .3 mm.

(7) Hardness measurement In this example, the hardness was measured as follows. SUS304 (stainless steel), which is the material of the PFA tube and the handling ring, and the rubber material 2d of Example 1 and the O-ring 2d of Example 2 are respectively used MD-1 E type of Kobunshi Keiki The measurement was carried out.

(8) Image Evaluation of Fixing Belt 20 The fixing belt 20 is manufactured using the comparative example of the above-described embodiment and the handling ring of the embodiment, and is mounted on the image evaluation apparatus, and is used for plain paper, coated paper, OHP. A full-color blue monochromatic image was output to each of the images to evaluate the occurrence of image defects.

  Evaluation was made as O = no occurrence, Δ = occurred with coated paper / OHP, and x = occurred with plain paper, and the occurrence rates were compared.

(9) Evaluation of handling unevenness Regarding the handling unevenness, the fixing belt 20 was manufactured using the comparative example of the present embodiment and the handling ring of the embodiment, and the appearance of the fixing belt 20 was visually evaluated. X = Evaluation was made assuming that uneven handling was confirmed visually, and that no uneven handling was confirmed.

  The results of the above (7), (8), and (9) are summarized in Table 1.

Above, the results of the various evaluations, the ring-like member R (FIG. 7, FIG. 8) of the first embodiment and the second embodiment when use the, when using the comparative example of the ring-shaped member R1 (Fig. 6) It was confirmed that the incidence of scratches was reduced.

  In addition, it can be seen that in Example 2, the PFA tube 24 and the handling ring R are closer to each other than the first example, but the scratches are not generated, the handling effect is high, and the handling unevenness does not occur. It was.

  As described above, the present invention is a tube coating method for obtaining a member coated with a tube by interposing an adhesive between a cylindrical or columnar substrate and the tube and curing the adhesive. Then, in the uncured state where the adhesive interposed between the base material and the tube is in a liquid or pasty state, the shaft of the tube is spouted while air is jetted from the ring-shaped member slightly larger than the member coated with the tube to the tube surface. Move in the direction. In addition, the hardness of the portion closest to the member covered by the tube of the ring-shaped member (the innermost diameter portion) is made of a material smaller than that of the tube (a material having a hardness equal to or less than that of the tube).

  With this configuration, the occurrence of scratches on the tube surface can be reduced. This also includes the effect of reducing the occurrence of scratches due to contact between the tube and the handling ring due to local changes in the outer diameter due to the bias of the adhesive. That is, a material having a hardness equal to or lower than that of the tube is used for the innermost diameter portion of the ring-shaped member as a sealing member for the blown air. As a result, the distance between the ring-shaped member main body and the object (tube) that causes damage to the tube can be made wider than that of the conventional air handling ring-shaped member R1, and the occurrence of tube damage is reduced. Can do.

[Other matters]
(1) In the first and second embodiments, the heating member 20 as the heating member that heats the image by contacting the image carrying surface of the recording material has been described as the fixing member. For the pressure member 30 which is the other fixing member forming the heating member 20 and the fixing nip 60, an adhesive is interposed between the cylindrical or columnar base material and the tube, and the tube is cured by curing the adhesive. A member having a coated configuration can also be used. Even in the case of manufacturing the pressure member 30 having such a configuration, the same effect can be obtained by applying the present invention.

  (2) In the first and second embodiments, the fixing member has been described in the form of an endless belt body, but is not limited thereto. As a fixing member, a rigid roller body (columnar shape) or hollow roller body (cylindrical shape) is used as a base, an elastic layer 22 is formed on the outer peripheral surface thereof, and a fluororesin tube 24 covering the surface is further provided. It may be in the form of a roller body.

  (3) In the image heating and fixing apparatus A, in addition to an apparatus that heats an unfixed toner image (developer image, developer image) by a fixing member and fixes or presupposes it as a fixed image, the fixed toner Also included are devices that reheat the image to modify the surface properties such as gloss.

  A..Image heating fixing device, 20..Fusing member (fixing belt), 30..Fusing member (pressure belt), 60..Fixing nip, 21 (W) ..Base material, 22..Elastic layer, 23 .. Adhesive layer, 24 .. Fluoropolymer tube, R .. Ring-shaped member, 2d.

Claims (5)

In a tube coating method for obtaining a member coated with the tube by interposing an adhesive between a cylindrical or columnar base material and a tube covering the outside of the base material, and curing the adhesive,
An extension step of extending the tube in the longitudinal direction after covering the tube with the base material in an uncured state where the adhesive is liquid or pasty ;
A fixing step of fixing one end side and the other end side of the tube in the longitudinal direction to the base material while maintaining extension in the longitudinal direction of the tube;
A handling step of handling the outer surface of the tube after the fixing step and handling excess adhesive between the substrate and the tube ;
A curing step of curing the adhesive after the handling step ,
In the handling step, a ring-shaped member having a slightly larger diameter than that of the member is externally fitted to the member covered with the tube, and then air is supplied from the ring-shaped member to the surface of the tube. At least the innermost diameter portion of the ring-shaped member, the step of handling the adhesive interposed between the base material and the tube by being moved in the axial direction while being jetted in a direction intersecting the axial direction A tube coating method characterized by using a material having a hardness equal to or less than that of the tube.   The tube coating method according to claim 1, wherein the material is a rubber material having a hardness lower than that of the tube.   The tube covering method according to claim 1 or 2, wherein at least the innermost diameter portion of the ring-shaped member is an O-ring made of a material having a hardness lower than that of the tube.   The tube covering method according to claim 1 or 2, wherein the ring-shaped member is made of two or more materials, and at least the innermost diameter portion is a material having a hardness smaller than that of the tube. The tube according to any one of claims 1 to 4, further comprising a cutting step of separating a region in which one end side and the other end side of the tube in the longitudinal direction are fixed to the base material after the curing step. Coating method.