Patent Application
20190041777
The present invention relates to a peeling member that peels a paper from a fixing member such as a fixing roller and a fixing belt arranged in an electronic photographic device such as a copying machine and a laser printer.
In an electronic photographic device such as a copying machine and a laser printer, a thermal fixing device that develops an electrostatic latent image formed on a photoreceptor drum on a paper by using a developing agent such as toner and then fixes the developed image is arranged. The thermal fixing device is provided with a fixing member such as a fixing roller and a fixing belt for fixing the developing agent on a paper by heating and melting and pressing the developing agent.
In the fixing member or a pressing roller that presses the fixing member against a paper, a sheet-like peeling member that peels a paper on which the developing agent is fixed from the roller or the like is used in order to prevent the paper from winding around the roller and interrupting smooth operation of the roller. As such a peeling member, a peeling member having a distal end portion of the peeling member covered with fluororesin in order to improve paper peeling performance and prevent a paper from being contaminated due to adhesion of the toner has been increasing.
For example, a peeling member having a distal end portion of a base material covered with a fluororesin film is disclosed in Patent Document 1. In Patent Document 1, the fluororesin film is adhered to a surface of the base material via a silicon-based adhesive (see Patent Document 1). Further, a peeling member having a distal end portion of a base material is covered with fluororesin coating film formed by a coating process is disclosed in Patent Document 2. In Patent Document 2, a spherical filler such as a resin balloon, a ceramic balloon, and a glass balloon is added to the fluororesin coating film (see Patent Document 2).
Further, in Patent Document 3, a configuration in which a plurality of recessed portions is formed on a surface of a resin coating film by forming a dimple like recessed portion on a paper passing surface of a metal plate as a base material, and a configuration in which a recessed portion is formed on a paper passing surface of a fluororesin film by forming a plurality of through holes on a paper passing surface of a sheet metal and adhering the fluororesin film on the sheet metal are disclosed (see Patent Document 3). In Patent Documents 2 and 3, a paper can be separated from the roller smoothly by reducing a contact area with the paper.
However, in the developing agent adopted in an electronic photographic device of recent years, in order to improve color developing performance, binder resin as one component of toner is changed to polyester binder resin with high transparency. Since the toner containing polyester binder resin has extremely high adhesiveness, a paper is adhered to a peeling sheet to which a fluororesin film is adhered or a paper passing surface having a flat shape of a peeling member coated with a resin coating film, and thereby jamming might occur.
In the peeling member disclosed in Patent Document 2, the spherical filler might be flocculated or deviation of a distribution of the spherical filler might be generated. In such a case, uniform recess and projection is not obtained, and therefore discharge of a paper is not performed smoothly because non-adhesiveness is locally different in the peeling member. Consequently, jamming might occur. Further, in the peeling member disclosed in Patent Document 3, the recessed portion is formed on the base material so that the recessed portion is formed on a surface of the resin coating film or the resin film. Thus, a minimum diameter of the recessed portion becomes large up to approximately φ 5 mm. Further, since strength of the base material is deteriorated by setting an interval of the recessed portions to be small, the interval of several millimeters is needed, however a paper might be adhered to a flat portion of the interval of the several millimeters. Especially, jamming of a thin paper on which a contact print is performed might occur.
High resolution, high printing speed, compactification, complexness of a flow of a paper caused by installation of a both-side copying function, or the like in the electronic photographic device is promoted in recent years, and when a paper is slightly adhered (attracted) to the peeling member, jamming or folding of a paper is generated and therefore a desired operation quality might not be maintained.
An object of the present invention is, in order to solve such a problem, to provide a peeling member formed by a metal plate or the like and a resin coating film formed on the metal plate, the peeling member being capable of preventing adhesion of a paper right after fixing for a long period of time, and to provide a manufacturing method for the peeling member capable of forming a fine recessed portion on a surface of the resin coating film for preventing the adhesion of the paper.
A peeling member of the present invention includes a peeling sheet formed by a base material having a plate shape, and a resin coating film formed on at least a surface of the base material at a paper passing side. The peeling member is formed to peel a paper from a fixing member of an electronic photographic device by arranging a distal end portion, which is an end portion at a side of one long side of the peeling sheet and at an upstream side in a paper passing direction, to be contacted with or close to the fixing member. The resin coating film includes a plurality of recessed portions on a surface of the resin coating film at the paper passing side, and a recess is not formed on the base material as a base part of the recessed portion.
Here, “to be contacted” means that one side (the distal end portion) of the peeling sheet is linearly contacted with the fixing member in an axial direction. Further, “to be close” means that the one side (the distal end portion) of the peeling sheet is arranged close to a roller to such an extent that a paper can be prevented from winding around the roller or the like. Further, the fixing member denotes a member formed in either of a roller-like shape, a film-like shape, or a belt-like shape capable of contacting with a paper in a step of heating and at the same time pressing an undeveloped developing agent on a paper so as to be fixed on the paper. Examples of the fixing member include a fixing roller, a pressing roller and the like.
The recessed portion may be formed as linear grooves inclined in one direction or two directions against the paper passing direction and aligned along a longitudinal direction of the peeling sheet at the same intervals.
The resin coating film may include a matrix resin containing at least powder of fluororesin and powder of graphite, and the resin coating film may contain 25 to 70 parts by weight of the fluororesin and 1 to 20 parts by weight of the graphite against 100 parts by weight of the matrix resin. Further, the matrix resin may be formed of a polyamide imide (PAI) resin. Further, the fluororesin may be formed of a polytetrafluoroethylene (PTFE) resin, and the graphite may contain 97.5% or more of fixed carbon.
A manufacturing method for the peeling member of the present invention includes a coating film forming step of forming a resin coating film by drying a resin coating material after applying the resin coating material including a matrix resin on at least a surface of the base material of the peeling member at the paper passing side, a coating film baking step of baking and hardening the resin coating film, and a recessed portion forming step of forming a portion, which becomes a recessed portion when the coating film baking step is performed, on the surface of the resin coating film at the paper passing side after the coating film forming step and before the coating film baking step.
The recessed portion may be formed as linear grooves inclined in one direction or two directions against the paper passing direction and aligned along a longitudinal direction of the peeling sheet at the same intervals, and the linear groove may be formed in the recessed portion forming step by pressing a rotation member including an outer periphery having a helical gear shape against the surface of the resin coating film while rotating.
The peeling member of the present invention includes the peeling sheet formed by the base material having a plate shape, and the resin coating film formed on at least the surface of the base material at the paper passing side, and the resin coating film includes a plurality of the recessed portions on the surface of the resin coating film at the paper passing side, and a recess is not formed on the base material as a base part of the recessed portion. Consequently, the peeling member has excellent paper peeling performance and toner non-adhesiveness, and printing of an image having an image ratio of 90% or more can be performed without adhesion and jamming of a paper to the peeling member. Further, since it is not necessary to perform a process of forming a projection and recess on the base material, high horizontal accuracy (straightness accuracy) of the distal end portion of the peeling sheet can be maintained, and less variation in quality can be achieved.
The recessed portion is formed as linear grooves inclined in one direction or two directions against the paper passing direction and aligned along a longitudinal direction of the peeling sheet at the same intervals. Consequently, excellent low friction performance can be especially obtained, and therefore adhesion of a paper right after the fixing can be further prevented. Further, the peeling member is contacted with a paper in a linear contact manner, and thereby image deterioration such as gloss unevenness and gloss stripes of the image can be prevented.
The resin coating film includes the matrix resin containing at least powder of fluororesin and powder of graphite, and the resin coating film contains 25 to 70 parts by weight of the fluororesin and 1 to 20 parts by weight of the graphite against 100 parts by weight of the matrix resin. Consequently, excellent low friction performance and wear resistance of the resin coating film can be obtained. Further, since the matrix resin is formed of the PAI resin, excellent heat resistance, wear resistance, and adhesiveness with the base material can be obtained.
The manufacturing method for the peeling member of the present invention includes the coating film forming step of forming a resin coating film by drying a resin coating material after applying the resin coating material including a matrix resin on at least a surface of the base material of the peeling member at the paper passing side, the coating film baking step of baking and hardening the resin coating film, and the recessed portion forming step of forming a portion, which becomes the recessed portion when the coating film baking step is performed, on the surface of the resin coating film at the paper passing side, after the coating film forming step and before the coating film baking step. That is, the recessed portion forming step is performed between the coating film forming step and the coating film baking step, and thereby the recessed portion is formed by means of transfer or the like in a state in which the resin coating film is flexible right after coating and drying, and then the resin coating film having the recessed portion can be formed by baking and hardening the flexible resin coating film. With this, fine and precise recessed portion can be formed on the surface of the peeling member, compared to a case in which the recessed portion is formed on the surface of the coating film after forming the coating film (after baking), or a case in which a recess is formed on the surface of the base material before forming the resin coating film.
The recessed portion is formed as linear grooves inclined in one direction or two directions against the paper passing direction and aligned along a longitudinal direction of the peeling sheet at the same intervals, and the linear groove is formed in the recessed portion forming step by pressing the rotation member including the outer periphery having a helical gear shape against the surface of the resin coating film while rotating. Consequently, excellent productivity of the peeling member can be obtained.
A fixing device using a peeling member of the present invention is described with reference to
One example of the peeling member of the present invention is described with reference to
The resin coating film 4 may be formed on at least the surface of the base material at a side through which a paper is passed (the paper passing side surface). In the configuration shown in
The pattern portion 5 on the paper passing side surface of the resin coating film 4 is formed by a plurality of the recessed portions 5a. The pattern portion 5 is formed in a region slid on a paper. A shape of the recessed portion is not especially limited, and therefore any shape such as a dimple recessed hole and a recessed groove may be adopted. Further, a depth of the recessed portion may be formed such that the recessed portion reaches the surface of the base material. The recessed groove may be formed as, for example, a geometrical pattern groove such as a one direction inclined pattern groove and a twill pattern groove. In the configuration shown in
The resin coating film 4 is obtained by coating the base material 2 with a resin coating material. The resin coating material is obtained by dispersing or dissolving a matrix resin and other compounding agent, each of which becomes a solid content, into a solvent. A detail of a forming method of the resin coating film 4 is described below.
As the matrix resin, resin having excellent adhesiveness and excellent heat resistance may be adopted. Specifically, examples of the matrix resin include a PAI resin, a polyphenylene sulfide (PPS) resin, a polyether ether ketone resin, a polyimide (PI) resin, a polyamide resin, an epoxy resin, and a phenol resin. Of these resins, the PAI resin is preferable because excellent heat resistance, wear resistance, and adhesiveness with the base material are obtained.
As the solvents into which the matrix resin or the like is dispersed, for example, ketones such as acetone, methyl ethyl ketone; esters such as methyl acetate and ethyl acetate; aromatic hydrocarbons such as toluene and xylene; organic halogen compounds such as methyl chloroform, trichloroethylene, and trichlorotrifluoroethane; and non-proton extreme solvents such as N-methyl-2-pyrrolidone (NMP), methylisopyrrolidone (MIP), dimethylformamide (DMF), dimethylacetamide (DMAC) may be used. These solvents can be used independently or as mixtures thereof. A kind of the solvent and viscosity thereof may be adjusted in accordance with a coating method of the resin coating material.
In order to further improve friction and wear performance of the resin coating film of the peeling member, it is preferable to compound at least fluororesin powder and carbon powder as a compounding agent into the matrix resin.
As the fluororesin, resin having heat resistance and capable of imparting low friction performance and unadhesiveness to the resin coating film may be adopted. Examples of the fluororesin, include a PTFE resin, a tetrafluoroethylene-perfluoroalkyl vinyl ether (PFA) copolymer resin, a tetrafluoroethylene-hexafluoropropylene (FEP) copolymer resin, and a tetrafluoroethylene-ethylene (ETFE) copolymer resin. Of these fluororesins, it is preferable to adopt powder of the PTFE resin.
In a case in which the powder of the PTFE resin is adopted, the average particle diameter (a value measured by laser analysis method) of the powder is not especially limited, however it is preferable that the average particle diameter is set to 30 μm or less to keep the surface smoothness of the resin coating film.
The powder of the PTFE resin obtained by baking the PTFE resin at a temperature of its melting point or more may be adopted. The powder obtained by irradiating the baked powder with y rays or electron rays may be also adopted. The baked powder of the PTFE resin has excellent uniform dispersion performance in the resin coating material and imparts excellent wear resistance to the formed resin coating film, compared to unbaked PTFE resin (molding powder, fine powder).
It is preferable that the resin coating film contains 25 to 70 parts by weight of the fluororesin such as the PTFE resin against 100 parts by weight of the matrix resin. In a case in which the compounding amount of the fluororesin is less than 25 parts by weight, the low friction performance is deteriorated, and thereby wear due to heat might be accelerated. On the other hand, in a case in which the compounding amount of the fluororesin exceeds 70 parts by weight, excellent low friction performance can be obtained, while strength of the coating film and the wear resistance might be deteriorated.
It is well known that the graphite has excellent characteristics as a solid lubricant. The graphite is classified into natural graphite and artificial graphite, however both of them can be adopted. Examples of a shape of the graphite include a flaky shape, a granular shape, and a spherical shape, and all of them can be adopted. It is preferable to adopt the graphite having 97.5% or more of fixed carbon, and more favorable to adopt artificial graphite having 98.5% or more of the fixed carbon
It is preferable that the resin coating film contains 1 to 20 parts by weight of the graphite against 100 parts by weight of the matrix resin. In a case in which the compounding amount of the graphite is less than 1 part by weight, the effect of adding the graphite to the matrix resin cannot be obtained sufficiently. On the other hand, in a case in which the compounding amount of the graphite exceeds 20 parts by weight, adhesiveness of the resin coating film is deteriorated, and therefore the resin coating film might be peeled.
In addition to the matrix resin, the fluororesin, and the graphite, the resin coating film may contain other additives unless necessary characteristics of the peeling member of the present invention are extremely deteriorated. In a case in which the total amount of the additives such as the fluororesin and the graphite against the matrix resin is less than 15 parts by weight, the resin coating film is ununiform in its thickness, and therefore it is difficult to obtain a required dimensional accuracy.
Further, it is preferable that tensile shear adhesive strength of the resin coating film is set to 25 MPa or more. In such a case, adhesion strength between the base material of the peeling member and the resin coating film becomes high, and therefore the peeling member can be used stably. In a case in which the resin coating film contains the PAI resin as the matrix resin, and the powder of the fluororesin and the powder of the graphite in the preferable compounding range described above, the tensile shear adhesive strength becomes 25 MPa or more.
The distal end portion 2a of the base material 2 is, for example, a part having a width of 4 mm from the distal end toward a downstream side in the paper passing direction. The distal end portion 2a of the base material 2 defines a distal end portion 1c of the peeling sheet 1a. Further, the peeling sheet is formed to peel a paper by arranging the distal end portion so as to be contact with or close to the fixing member, and therefore the distal end portion 1c of the peeling sheet 1a is defined as an end portion at the upstream side in the paper passing direction.
The material of the base material 2 is not especially limited as long as the distal end portion of the peeling sheet can be arranged to be contacted with or close to the fixing member, and therefore a metal material or a resin material may be adopted. As the metal material, for example, steel, aluminum, copper, stainless steel or the like may be adopted. Especially, stainless steel is preferable because stainless steel is not rusted, stainless steel is processed easily and obtained at a low cost. As the resin material, resin having heat resistance that can endure a temperature in baking of the resin coating film may be adopted, and therefore a heat resistant resin such as a liquid crystal polymer reinforced by fiber, a PPS resin and a PI resin may be adopted. In a case in which the resin material is adopted, a resin plate as the base material is formed by means of injection molding or extrusion molding from the resin material.
A plate thickness of the metal plate or the resin plate as the base material 2 is preferably set in a range between 50 μm and 300 μm. In a case in which the plate thickness is less than 50 μm, peeling force might not be secured, or the base material 2 might be deformed in jamming. In a case in which the plate thickness exceeds 300 μm, a paper to be peeled is abutted against the distal end portion of the peeling sheet and thereby jamming might occur. Further, the base material 2 has a contact width L (see
Further, it is preferable that the distal end portion 2a of the base material 2 at the upstream side in the paper passing direction is formed in a curved surface without an edge in a thickness direction. Since the end portion is formed in a curved surface in the thickness direction, even if the end portion is contacted with the fixing member such as the fixing roller and the fixing belt in a pressing contact state with more than certain pressure, the surface of the fixing member is not damaged. Further, the resin coating film is formed on the distal end portion 2a easily.
As shown in
A fixing method for the base material 2 and the support member 1b is not especially limited. In a case in which the base material 2 is formed of a metal plate and the support member 1b is formed of a metal thick plate, the base material 2 and the support member 1b are connected to each other by means of welding or the like. In a case in which welding is adopted to connect the base material 2 and the support member 1b, in order to prevent horizontal accuracy of the distal end portion 2a from being deteriorated due to a shape change of the base material 2, it is preferable to connect the base material 2 and the support member 1b by using laser spot welding in which spot portions are arranged parallel to the longitudinal direction.
A manufacturing method of the present invention is for manufacturing such a peeling member. The manufacturing method of the present invention is described with reference to
At first, as shown in (a) of
(1) Coating Film Forming Step
As shown in (b) of
The drying in this step is performed to such an extent that the recessed portion can be formed in the next step of the recessed portion forming step. At this stage, the solvent included in the resin coating film is vaporized. In a state in which much solvent is remained in the resin coating material, the resin coating film has liquidity, and even if a recessed portion is formed by means of transfer, the coating material flows and therefore the recessed portion is collapsed. Thus, the resin coating material is dried to such an extent that a groove is not collapsed when forming the recessed portion even if a part of the solvent is remained in the resin coating film. Further, in a case in which a powder coating method is adopted, the process proceeds to the next step in a state in which the resin coating material is in a flexible gel state before the resin coating material is completely hardened. Specifically, it means a state in which a ratio of the solid content in the resin coating film is 70 wt. % or more. The ratio of the solid content in the resin coating film can be managed easily by measuring each weight of a product before coating, right after coating, and after drying.
Further, by setting a film thickness of the resin coating film after drying to 12 μm to 36 μm, the resin coating film after baking is formed in a required film thickness. Further, in a case in which a finishing process is performed after baking, the film thickness of the resin coating film after drying may be set to 20 μm to 50 μm.
(2) Recessed Portion Forming Step
As shown in (c) of
The shape of the recessed portion is described above. In a case in which the recessed portion is formed as liner grooves inclined in one direction or two directions against the paper passing direction and aligned along the longitudinal direction of the peeling sheet at the same interval, namely in a case of the one direction inclined pattern groove and the twill pattern groove, as shown in (c) of
(3) Coating Film Baking Step
As shown in (d) of
The thickness of the resin coating film in the peeling member 1 is 10 μm to 30 μm. The finishing process may be performed by cutting the surface of the resin coating film after the baking by using a cutting tool so as not to collapse the groove. The peeling member 1 having the pattern portion 5 obtained by this manufacturing method can reduce an area directly slid on a paper due to a fineness of the pattern portion 5.
The peeling member 1 shown in
The peeling member of the example 1 was set in a fixing portion of a heat roller type test copying machine (fixing temperature of 190° C., copying speed of A4 size of 57 sheets/minute), and continuous paper feeding of 1,000 sheets of A4 plain papers on which a line chart having an image ratio of 80% was printed was performed, and then printing of an image having an image ratio of 99% on A4 plain papers was performed. After that, occurrence of the jamming due to adhesion was checked. As a result, the printing was performed without any problem. Adhesion of toner and damage of the resin coating film were not generated on the resin coating film checked after the paper feeding test.
A peeling member 11 shown in
The peeling member was set in the test copying machine used in the example 1, and the copying test in which the papers are continuously fed as same as that in the example 1 was performed. As a result of the test, in the paper peeling device of the comparative example 1, the continuous paper feeding of 1,000 sheets of A4 plain papers on which a line chart having an image ratio of 80% was printed was completed without any problem, however when the printing of an image having an image ratio of 99% on A4 plain papers was performed, the paper was adhered to the peeling member and the jamming due to the adhesion occurred.
The peeling member of the present invention formed by a metal plate or the like and a resin coating film formed on the metal plate can prevent adhesion of a paper right after fixing for a long period of time, and therefore the peeling member is preferably used for peeling a paper from various rollers such as a fixing roller installed in an electronic photographic device.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2015-182312 | Sep 2015 | JP | national |
| 2016-180053 | Sep 2016 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2016/077344 | 9/15/2016 | WO | 00 |
