阅读说明：本技术 电子照相设备用定影构件 (Fixing member for electrophotographic apparatus ) 是由 高木和典 松田浩稔 伊藤大辉 渡边泰秀 丸山勇 仲市真吾 早崎康行 于 2020-05-21 设计创作，主要内容包括：提供一种通过降低金属层的弯曲疲劳和提高密接性而提高了耐久性的电子照相设备用定影构件。电子照相设备用定影构件10具备基层12、形成于基层12上的金属层14、以及形成于金属层14上的保护层16,金属层14由规定的图案构成,基层12具有被金属层14覆盖的面12a和未被金属层14覆盖的面12b,保护层16连续地覆盖基层12的未被金属层14覆盖的面12b和金属层14的面,并且与基层12的未被金属层14覆盖的面12b粘接,基层12以及保护层16含有在重复单元中包含酰亚胺键的树脂。(Provided is a fixing member for an electrophotographic apparatus, which has improved durability by reducing bending fatigue of a metal layer and improving adhesion. The fixing member 10 for an electrophotographic apparatus includes a base layer 12, a metal layer 14 formed on the base layer 12, and a protective layer 16 formed on the metal layer 14, the metal layer 14 being formed of a predetermined pattern, the base layer 12 having a surface 12a covered with the metal layer 14 and a surface 12b not covered with the metal layer 14, the protective layer 16 continuously covering the surface 12b not covered with the metal layer 14 of the base layer 12 and the surface of the metal layer 14 and being bonded to the surface 12b not covered with the metal layer 14 of the base layer 12, the base layer 12 and the protective layer 16 containing a resin containing an imide bond in a repeating unit.)

1. A fixing member for an electrophotographic apparatus, characterized in that,

the fixing member for an electrophotographic apparatus includes a base layer, a metal layer formed on the base layer, and a protective layer formed on the metal layer,

the metal layer is formed of a predetermined pattern, the base layer has a surface covered with the metal layer and a surface not covered with the metal layer,

the protective layer continuously covers a face of the base layer not covered with the metal layer and a face of the metal layer, and is bonded to a face of the base layer not covered with the metal layer,

the base layer and the protective layer contain a resin containing an imide bond in a repeating unit.

2. A fixing member for an electrophotographic apparatus according to claim 1, wherein the resin containing an imide bond in the repeating unit is a polyimide resin.

3. The fixing member for an electrophotographic apparatus according to claim 1 or 2, wherein a thickness of the metal layer is in a range of 1.0 to 10 μm.

4. The fixing member for an electrophotographic apparatus according to any one of claims 1 to 3, wherein an area ratio of a face bonded to the protective layer in the entire face of the base layer is in a range of 20 to 75%.

5. The fixing member for an electrophotographic apparatus according to any one of claims 1 to 4, wherein a thickness of the protective layer on the metal layer is in a range of 10 to 50 μm.

Technical Field

The present invention relates to a fixing member for an electrophotographic apparatus.

Background

In an electrophotographic apparatus such as a copying machine, a printer, and a facsimile machine employing an electrophotographic system, a toner image is formed on a recording medium (such as paper), and the toner image is heated and pressed by a heating member (fixing member) to be fixed, thereby forming an image. The heating member (fixing member) has a metal layer as a heat generating layer. In order to improve the durability of the metal layer, as in patent document 1, a structure having a concave-convex shape in which a peak portion and a trough portion are formed into a curved surface on the outer side or the inner side of the metal layer is proposed. Patent document 1 also describes forming a protective layer on the outer surface of the metal layer.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2012 and 98586

Disclosure of Invention

Problems to be solved by the invention

In the fixing member of patent document 1, there is a risk that cracks or fractures may occur in the metal layer due to repeated bending fatigue. Further, repeated use may cause peeling between the metal layer and the base material. This is presumably because the metal layer is likely to be cracked or broken due to the difference in elastic modulus between the resin of the substrate and the metal layer and the concentration of stress in the metal layer having poor flexibility. The reason for this is assumed to be that peeling easily occurs between the metal layer and the substrate due to the difference between the stress applied to the metal layer and the stress applied to the substrate.

The problem to be solved by the present invention is to provide a fixing member for an electrophotographic apparatus having improved durability by reducing bending fatigue of a metal layer and improving adhesion.

Means for solving the problems

In order to solve the above-described problems, a fixing member for an electrophotographic apparatus according to the present invention includes a base layer, a metal layer formed on the base layer, and a protective layer formed on the metal layer, the metal layer having a predetermined pattern, the base layer having a surface covered with the metal layer and a surface not covered with the metal layer, the protective layer continuously covering the surface not covered with the metal layer of the base layer and the surface not covered with the metal layer and being bonded to the surface not covered with the metal layer of the base layer, and the base layer and the protective layer containing a resin containing an imide bond in a repeating unit.

The resin containing an imide bond in the repeating unit is preferably a polyimide resin. The thickness of the metal layer is preferably within the range of 1.0-10 μm. The area ratio of the surface of the base layer bonded to the protective layer is preferably in the range of 20 to 75%. The thickness of the protective layer on the metal layer is preferably within the range of 10-50 μm.

Effects of the invention

According to the fixing member for an electrophotographic apparatus of the present invention, since the protective layer continuously covers the surface of the base layer not covered with the metal layer and the surface of the metal layer, and the metal layer is embedded between the base layer and the protective layer, stress concentration to the metal layer is reduced, generation of cracks and fractures of the metal layer due to repeated bending fatigue is suppressed, and bending fatigue of the metal layer is reduced. Further, since the base layer and the protective layer each contain a resin containing an imide bond in a repeating unit and the protective layer is bonded to the base layer on the surface of the base layer not covered with the metal layer, peeling between the metal layer and the base layer due to repeated use can be suppressed. Thus, the durability is improved by reducing the bending fatigue of the metal layer and improving the adhesion.

Drawings

Fig. 1 is a schematic external view of a fixing member for an electrophotographic apparatus according to an embodiment of the present invention.

Fig. 2 (a) is a sectional view taken along line a-a of the fixing member for an electrophotographic apparatus of fig. 1, and fig. 1 (B) is a part of a sectional view taken along line B-B.

Fig. 3 is a process diagram for manufacturing a fixing member for an electrophotographic apparatus according to an embodiment of the present invention.

Fig. 4 is a part of an axial cross section of a fixing member for an electrophotographic apparatus according to another embodiment of the present invention.

Fig. 5 is a schematic diagram illustrating a method of evaluating durability of the fixing member.

Detailed Description

Fig. 1 is a schematic external view of a fixing member for an electrophotographic apparatus according to an embodiment of the present invention. Fig. 2 (a) is a sectional view taken along line a-a of the fixing member for electrophotographic apparatus of fig. 1, and fig. 2 (B) is a part of a sectional view taken along line B-B of the fixing member for electrophotographic apparatus of fig. 1.

As shown in fig. 1, a fixing member 10 for an electrophotographic apparatus according to an embodiment of the present invention (hereinafter, may be simply referred to as a fixing member 10) is formed in a cylindrical shape and has a seamless structure with no seam in the circumferential direction. As shown in fig. 2 (a) and (b), the fixing member 10 includes a base layer 12, a metal layer 14 formed on the base layer 12, and a protective layer 16 formed on the metal layer 14. The fixing member 10 functions as a heating member (fixing member) in a fixing process of the electrophotographic apparatus. The fixing member 10 is illustrated as a fixing belt formed in a cylindrical shape, but the fixing member according to the present invention may be a fixing roller formed in a roller shape on the outer periphery of a shaft body.

The base layer 12 is formed as a substrate of the fixing member 10. The base layer 12 is formed in a cylindrical shape and has a seamless structure without seams in the circumferential direction. The base layer 12 is composed of a material containing an organic polymer. The organic polymer constituting the base layer 12 is preferably an organic polymer having excellent heat resistance. The organic polymer constituting the base layer 12 is a resin containing an imide bond in a repeating unit from the viewpoint of heat resistance, strength, and the like. Examples of the resin containing an imide bond in a repeating unit include a polyimide resin and a polyamideimide resin. The polyimide resin and the polyamideimide resin may be modified polyimide resins and modified polyamideimide resins.

Additives and the like may also be contained in the base layer 12. Examples of the additives include a release agent, a flame retardant, a filler, a leveling agent, and an antifoaming agent.

The thickness of the base layer 12 is not particularly limited, but is preferably within a range of 20 to 200 μm from the viewpoint of durability, manufacturability, and the like. More preferably 25 to 140 μm, and still more preferably 30 to 80 μm.

The metal layer 14 generates heat when energized. In the heat generation principle based on induction heating using the IH coil, when an ac current is supplied to the IH coil disposed in the vicinity of the fixing member 10, a magnetic field is induced, and eddy current is generated in the metal layer 14 of the fixing member 10 by the magnetic field, and the metal layer 14 generates heat. As shown in fig. 2 (a), the metal layer 14 extends in the circumferential direction of the cylindrical fixing member 10, and is formed in a ring shape in the circumferential direction. As shown in fig. 2 (b), a plurality of metal layers 14 formed annularly in the circumferential direction are arranged at predetermined intervals in the axial direction of the cylindrical fixing member 10. Each of the plurality of metal layers 14 is formed of metal wires having the same width and the same thickness. By this repeated structure, a predetermined pattern is formed. The pattern shape of the metal layer 14 is not particularly limited. As shown in fig. 2 (a) and (b), the fixing member 10 may be formed in a ring shape in the circumferential direction or may extend in the axial direction. Alternatively, the spiral shape may be formed in the axial direction. The fixing member 10 is configured to generate heat uniformly on its outer peripheral surface, and is configured not to generate temperature unevenness. As described later, the metal layer 14 (metal wire) is formed by plating. Such a fixing member has high heat transfer efficiency, and the surface temperature of the fixing member can be quickly raised to a predetermined temperature after the start of energization to the resistance heating element, and the temperature can be raised quickly.

Since the metal layer 14 is formed in a predetermined pattern, the base layer 12 has a structure having a surface 12a covered with the metal layer 14 and a surface 12b not covered with the metal layer 14.

Examples of the metal constituting the metal layer 14 include Cu, Ni, Ag, Pd, Sn, Au, and an alloy of one or more of these metals.

The thickness of the metal layer 14 is not particularly limited, and is preferably 1.0 μm or more from the viewpoint of heat generation property, durability, and the like. More preferably 2.0 μm or more, and still more preferably 3.0 μm or more. In addition, from the viewpoint of durability, it is preferably 10 μm or less. More preferably 8.0 μm or less, and still more preferably 7.0 μm or less.

The width of the metal layer 14 is preferably 0.1mm or more from the viewpoint of manufacturability, heat generation property, and the like. More preferably 0.2mm or more. In addition, from the viewpoint of easily reducing temperature unevenness, it is preferably 0.5mm or less. More preferably 0.4mm or less.

The interval between the metal layers 14 is preferably 0.1mm or more from the viewpoint of improving manufacturability, heat generation property, and the like. More preferably 0.15mm or more. In addition, from the viewpoint of easily reducing temperature unevenness, it is preferably 0.3mm or less. More preferably 0.25mm or less.

The protective layer 16 protects the surface of the metal layer 14. The surface of the metal layer 14 is a surface disposed radially outward of the fixing member 10. The protective layer 16 is formed on the metal layer 14 to cover the surface of the metal layer 14. The protective layer 16 is formed not only on the metal layer 14 but also on the base layer 12 between the metal layer 14 and the metal layer 14, which is not covered with the metal layer 14, and also covers the surface 12b of the base layer 12, which is not covered with the metal layer 14. The surface 12b of the base layer 12 not covered with the metal layer 14 is a surface not covered with the metal layer 14 among the surfaces of the base layer 12 disposed radially outward of the fixing member 10. In this way, the protective layer 16 continuously covers the surface 12b of the base layer 12 not covered with the metal layer 14 and the surface of the metal layer 14, and the metal layer 14 is embedded between the base layer 12 and the protective layer 16. The protective layer 16 is in contact with the surface 12b of the base layer 12 not covered with the metal layer 14, and is bonded to the surface 12b of the base layer 12 not covered with the metal layer 14, since it contains a resin containing an imide bond in a repeating unit, as in the base layer 12. Further, the resin containing an imide bond in the repeating unit is a resin exemplified in the base layer 12.

The protective layer 16 continuously covers the surface 12b of the base layer 12 not covered with the metal layer 14 and the surface of the metal layer 14, and the metal layer 14 is embedded between the base layer 12 and the protective layer 16, so that stress concentration on the metal layer 14 is reduced, occurrence of cracks or fractures in the metal layer 14 due to repeated bending fatigue is suppressed, and bending fatigue of the metal layer 14 is reduced. Further, since the base layer 12 and the protective layer 16 each contain a resin containing an imide bond in a repeating unit and the protective layer 16 is bonded to the base layer 12 on the surface 12b of the base layer 12 not covered with the metal layer 14, peeling between the metal layer 14 and the base layer 12 due to repeated use can be suppressed. In this way, the durability is improved by reducing the bending fatigue of the metal layer 14 and improving the adhesion. Further, by forming the protective layer 16 on the metal layer 14, the surface unevenness caused by the metal layer 14 is smoothed, and the surface of the fixing member 10 becomes smooth, so that the contact surface with the printed matter becomes uniform.

Examples of the combination of the resin containing an imide bond in a repeating unit contained in the base layer 12 and the resin containing an imide bond in a repeating unit contained in the protective layer 16 include a combination of a polyimide resin and a polyamideimide resin in the former, a combination of a polyamideimide resin and a polyimide resin in the latter, a combination of a polyimide resin in the former and a polyamideimide resin in the latter, a combination of a polyamideimide resin in the both, and a combination of a polyamideimide resin in the both. Among them, from the viewpoint of durability, strength, and the like, both are preferably polyimide resins.

The protective layer 16 may also contain a thermally conductive filler. When the protective layer 16 contains the heat conductive filler, the heat conductivity of the protective layer 16 is improved, and the heat generated by the metal layer 14 is efficiently transmitted to the outer circumferential surface of the fixing member 10. The protective layer 16 may also contain additives and the like. Examples of the additives include a release agent, a flame retardant, a filler, a leveling agent, and an antifoaming agent.

The thickness of the protective layer 16 on the metal layer 14 is preferably 10 μm or more from the viewpoint of durability, adhesion of the metal layer 14, and the like. More preferably 15 μm or more. From the viewpoint of heat generation property, it is preferably 50 μm or less. More preferably 40 μm or less, and still more preferably 30 μm or less.

From the viewpoint of adhesion of the metal layer 14, the area ratio of the surface of the base layer 12 bonded to the protective layer 16 is preferably 20% or more. More preferably 30% or more. From the viewpoints of suppressing a decrease in heat generation property due to a decrease in the area ratio of the metal layer 14, suppressing a decrease in durability, and the like, the area ratio of the surface bonded to the protective layer 16 in the entire surface of the base layer 12 is preferably 75% or less. More preferably 70% or less, and still more preferably 60% or less. The entire surface of the base layer 12 refers to the entire outer peripheral surface of the base layer 12.

A plating base layer 18 is provided beneath the metal layer 14 and on the base layer 12. The plating base layer 18 is a layer to be a base for forming the metal layer 14 by plating. The plating base layer 18 is configured in a predetermined pattern in the same manner as the metal layer 14. The plating base layer 18 contains at least a plating catalyst necessary for plating. The plating base layer 18 is in contact with the metal layer 14 and the base layer 12, respectively. The plating base layer 18 is formed in the same pattern shape as the metal layer 14 with the same width as the metal layer 14.

The fixing member 10 can be manufactured, for example, as follows. First, a plating base layer 18 having a predetermined pattern is formed on the base layer 12. Next, plating is performed on the formed plating base layer 18 to form the metal layer 14 of a predetermined pattern.

First, as shown in fig. 3 (a), the base layer 12 is prepared. The base layer 12 may be formed using a base layer-forming material containing an organic polymer. When the base layer 12 is cylindrical (belt-shaped), a base layer forming material (paint) is applied to the outer peripheral surface of a cylindrical or columnar mold and dried. If necessary, heat treatment may be performed. Examples of the coating method include a dip coating method, a dispenser coating method (nozzle coating method), a roll coating method, and a ring coating method. When the base layer 12 is in the form of a roll, a base layer-forming material (kneaded material) is injected into a roll-forming mold and heat-treated. Alternatively, the base layer-forming material (kneaded product) is extruded and molded.

Next, as shown in fig. 3 (b), a plating base layer 18 having a predetermined pattern is formed on the base layer 12. The plating base layer 18 can be formed by screen printing using a base forming material (paint) containing a plating catalyst and a binder. Drying and heat treatment may be performed as necessary. Further, degreasing treatment, cleaning treatment, and the like may be performed after screen printing. The plating base layer 18 becomes a coating film containing a plating catalyst and a binder.

The plating catalyst may have a catalytic ability necessary for plating on the plating base layer 18. Examples of such a catalyst metal include Pt group metals such as Pd and Pt, Ag and Au, and alloys thereof. One kind of these may be used alone as a catalyst metal for plating, or two or more kinds may be used in combination. Among them, Pd, Pt, Ag, and alloys thereof are more preferable from the viewpoint of more excellent catalytic ability. In addition, Pd is particularly preferable.

Examples of the binder include polyimide, polyamideimide, modified polyimide, polyethersulfone, fluororesin, and polycarbonate.

In the material (coating material) for forming a base, the solid content concentration of the plating catalyst is preferably 0.1 mass% or more from the viewpoint of plating efficiency and the like. More preferably 0.5 mass% or more. From the viewpoints of dispersibility of the plating catalyst, adhesion of the metal layer 14, and the like, the content is preferably 10.0 mass% or less. More preferably 6.0 mass% or less.

The thickness of the plating base layer 18 is not particularly limited, but is preferably 0.05 μm or more from the viewpoint of adhesion to the base layer 12 and the metal layer 14, uniformity, and the like. More preferably 0.1 μm or more, and still more preferably 0.3 μm or more. From the viewpoint of economy, the thickness is preferably 10 μm or less. More preferably 5.0 μm or less, and still more preferably 3.0 μm or less.

Next, as shown in fig. 3 (c), plating is performed to form the metal layer 14 on the plating base layer 18. The metal layer 14 may be formed by electroless metal plating. Electroless metal plating is performed using a plating solution. After plating, washing with water or the like may be performed as necessary.

The plating solution contains metal ions, a reducing agent, a complexing agent, a pH buffer, and the like. The metal ions are ions of the plating metal. Examples of the plating metal include Cu, Ni, Ag, Pd, Sn, Au, and alloys thereof. Among them, Cu, Ni, Ag, and alloys thereof are more preferable from the viewpoint of excellent adhesion to the plating base. In addition, from the viewpoint of catalytic activity of the plating base with respect to the catalyst metal, adhesion to the plating base, and the like, Ni and Ni alloys are particularly preferable.

Examples of the reducing agent include hypophosphorous acid, hypophosphite, dimethylamine borane, and hydrazine. Among them, hypophosphorous acid and hypophosphite are preferable from the viewpoint of stability of the plating solution. Examples of the pH buffer include lactic acid, acetic acid, and succinic acid.

Examples of the complexing agent include carboxylic acids and amine compounds. The complexing agent may be a carboxylic acid alone, an amine compound alone, or a combination of a carboxylic acid and an amine compound. Examples of the carboxylic acid include citric acid, malic acid, tartaric acid, and ethylenediaminetetraacetic acid (EDTA). Examples of the amine compound include glycine, alanine, ethylenediamine, and propylenediamine.

The plating solution may further contain a surfactant. Examples of the surfactant include a cationic surfactant and an amphoteric surfactant.

Examples of the cationic surfactant include quaternary ammonium salt type cationic surfactants such as lauryl trimethyl ammonium chloride and ethylene oxide adduct ammonium chloride. They may be used alone or in combination. Examples of the amphoteric surfactant include betaine-type amphoteric surfactants such as lauryl betaine, amidopropyl betaine, and dimethyl alkyl betaine. They may be used alone or in combination. The amount of the cationic surfactant or the amphoteric surfactant is preferably in the range of 0.01 to 10 g/L.

Next, as shown in fig. 3 (d), on the surface of the base layer 12 on the side where the metal layer 14 is formed, a protective layer forming material is filled on the metal layer 14 and between the metal layer 14 and the metal layer 14 so as to continuously cover the surface 12b of the base layer 12 not covered with the metal layer 14 and the surface of the metal layer 14, and the protective layer forming material is applied so that the outer side surfaces of the protective layer 16 are coplanar and dried. The heat treatment may be performed as needed. Examples of the coating method include a dip coating method, a dispenser coating method (nozzle coating method), a roll coating method, and a ring coating method.

While the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the present invention.

For example, one or more cover layers may be formed on the outer side of the protective layer 16 of the fixing member 10 so as to cover the protective layer 16 over the entire circumference. The cover layer may be formed of, for example, an insulating material, a rubber elastic material, a fluororesin material, or the like.

Fig. 4 shows a fixing member 20 according to another embodiment. The fixing member 20 is formed in a cylindrical shape and has a seamless structure without a seam in the circumferential direction. The fixing member 20 includes a base layer 12, a metal layer 14 formed on the base layer 12, a protective layer 16 formed on the metal layer 14, an elastic layer 22 formed on the protective layer 16, and a surface layer 24 formed on the elastic layer 22.

The fixing member 20 differs only in that the elastic layer 22 and the surface layer 24 are provided on the protective layer 16, and the other structures are the same as the fixing member 10, and the description of the same structures is omitted.

The elastic layer 22 is made of an elastic material such as a rubber material. Examples of the elastic material include silicone rubber and fluororubber. The elastic layer 22 can be formed by applying an elastic material such as a rubber material as a paint on the protective layer 16. The thickness of the elastomer layer 22 is not particularly limited, and may be 120 to 450 μm.

The surface layer 24 is preferably made of a material having a high releasability from the toner. Examples of the material of the surface layer 24 include polymers for surface layers such as fluororesins and fluororubbers. The skin layer 24 can be formed by covering the outside of the elastomer layer 22 with a material obtained by molding the material of the skin layer 24 into a tubular shape. The thickness of the surface layer 24 is not particularly limited, and may be 3 to 50 μm.

In the above embodiment, the case where the plating base layer 18 is a coating film containing a plating catalyst and a binder is exemplified, but the plating base layer 18 may be formed by a conventional method of applying a catalyst to the base layer 12. Specifically, the catalyst for electroless plating may be adsorbed on the surface of the base layer 12 and then subjected to reduction treatment, thereby providing the base layer 12 with the catalyst metal for electroless plating. In order to adsorb the catalyst for electroless plating on the surface of the base layer 12, the surface of the base layer 12 is preferably activated. For example, a hydrophilic group such as a hydroxyl group or a carboxyl group may be generated on the surface of the base layer 12, and a catalyst for electroless plating may be provided on the surface of the base layer 12. The hydrophilic group of the base layer 12 can be formed relatively easily by hydrolysis based on alkali treatment. The reduction treatment may be a method (alkaline catalysis method) in which a metal ion-water-soluble polymer complex solution such as Pd is brought into contact with the base layer, and then the metal ion is reduced with a reducing agent containing dimethylamine borane, sodium borohydride, or the like, and the water-soluble polymer is removed to precipitate a metal. In addition, a sensitizer-activator method, a catalyst-acceleration method, or the like, which utilizes the reducing power of tin ions, may be used.

Examples

The present invention will be described in detail below with reference to examples and comparative examples.

< Material for Forming base layer >

PI: "U-imide AR" (polyimide) manufactured by UNITIKA

< Material for Forming protective layer >

PI: "U-imide AR" (polyimide) manufactured by UNITIKA

PAI: "VYLOMAX HR-16 NN" (polyamideimide) manufactured by Toyo Boseki Kabushiki Kaisha

PA: "TORESIN EF-30" (Polyamide) manufactured by Dongli

< Material for Forming plating base >

A material for forming a plating base containing Pd was used.

< degreasing fluid >

A degreasing solution was prepared by mixing 200ml of an alkaline degreasing agent ("OPC-190 cleaner" manufactured by Oney pharmaceutical Co., Ltd.), 1200ml of 3 mass% caustic soda and 600ml of ion-exchanged water.

< regulator solution >

As the regulator solution, a cationic surface conditioner ("CONDIRIZER FR CONC") was used at 50 ml/L.

< electroless Metal plating solution >

By mixing nickel sulfate hexahydrate: 26g/L, sodium hypophosphite monohydrate (reducing agent): 32g/L, sodium citrate dihydrate (complexing agent): 30g/L were mixed to prepare an electroless metal plating solution.

(examples 1 to 14)

< preparation of base layer >

A base layer-forming material was applied to the surface of a cylindrical aluminum tube having a diameter of 30mm and an axial length of 450mm by a dip coating method, and dried at 230 ℃ for 60 minutes. Thereafter, the mixture was heated at 350 ℃ for 30 minutes. The pull rate in the coating was 100 mm/sec. Thereby, a cylindrical base layer (having a thickness of 50 μm) was formed on the outer peripheral surface of the cylindrical tube.

< preparation of plating base layer and Metal layer >

The plating base forming material was pattern-coated in a linear shape on the surface of the formed base layer by screen printing, and after heat treatment at 120 ℃ for 15 minutes, further heat treatment was performed at 240 ℃ for 15 minutes. Thereby, a plating base layer (having a thickness of 0.5 μm) having a predetermined pattern was formed on the base layer. Thereafter, the plate was immersed in a degreasing solution at 65 ℃ for 5 minutes, and then washed with pure water. Thereafter, the plating bath was immersed in an electroless metal plating solution (plating bath temperature: 84 ℃ C.), and then washed with pure water. Thereby, a metal layer patterned into a line shape (nickel plating) is formed on the plating base layer. The plating base layer and the metal layer are formed in a ring shape with a predetermined line width along the circumferential direction of the base layer, and the plurality of ring-shaped plating base layers and the plurality of metal layers are arranged at predetermined intervals in the axial direction of the base layer. In example 1, the line width of the plating base layer was set to 1mm, and the interval between the plating base layers was adjusted so that the contact area ratio between the protective layer and the base layer became a predetermined value. In each of examples and comparative examples, the number of plating base layers to be formed was the same, and the line width of the plating base layer in the other examples and comparative examples was adjusted so that the contact area ratio between the protective layer and the base layer became a predetermined value. The thickness of the metal layer is adjusted by the plating time.

< preparation of protective layer >

On the surface of the formed base layer on the side where the metal layer is formed, a protective layer forming material is filled on the metal layer and between the metal layer and the metal layer so as to continuously cover the surface of the base layer not covered with the metal layer and the surface of the metal layer, and as shown in fig. 2 (b), the protective layer forming material is applied so that the outer side surfaces of the protective layer become coplanar. Thereafter, the heat treatment is performed under predetermined heat treatment conditions. Thereby, a protective layer is formed on the base layer. The thickness of the protective layer on the metal layer is adjusted by the coating amount of the protective layer forming material. According to the above, a fixing member for an electrophotographic apparatus having a base layer, a metal layer and a protective layer was produced.

(Heat treatment Condition)

·PI：80℃×30min+120℃×30min+200℃×30min+350℃×30min

·PAI：230℃×60min

·PA：130℃×30min

Comparative example 1

A fixing member for an electrophotographic apparatus having a base layer and a metal layer was produced in the same manner as in example 1, except that the protective layer was not formed.

Comparative example 2

A fixing member for an electrophotographic apparatus having a metal layer on the entire outer peripheral surface of a base layer was produced in the same manner as in example 1, except that a material for forming a plating base was applied to the entire outer peripheral surface of the base layer without screen printing.

Comparative example 3

A fixing member for an electrophotographic apparatus having a base layer, a metal layer, and a protective layer was produced in the same manner as in example 1, except that the material for forming a protective layer was nylon (polyamide).

Using each of the prepared fixing members for electrophotographic apparatuses, the following durability evaluation, adhesion evaluation, and heat generation evaluation were performed. The results are shown in table 1.

< durability >

As shown in fig. 5, the sample 1 was subjected to a tensile durability test by applying a load 7(1kg) to both shafts and rotating the rotary shafts (Φ 6)2a and 2b at 1000 rpm. The durability time was 2 hours, the "excellent" was evaluated as the case where no cracks were generated in the metal layer at all, the "o" was evaluated as the case where cracks were generated in the metal layer and the number of generated cracks was 1 to 3, the "Δ" was evaluated as the case where the number of generated cracks was 4 to 6, and the "x" was evaluated as the case where the number of generated cracks was 7 or more.

< adhesion >

The thus-prepared fixing member was left at 200 ℃ for 1 hour, and then a cross-cut test was carried out on the fixing member in accordance with JIS-K5600-5-6. After 1mm × 1mm cross cutting (25 squares in total) was performed so that the blade edge reached the base layer from the protective layer side of the fixing member, a tape peeling test was performed. As the tape, PTFE tape (P-422) manufactured by Nitto electrician was used. The case where the metal layer was not peeled off at all from the base layer was evaluated as "excellent", the case where the metal layer was peeled off from the base layer and the number of squares of the peeling was 1 square grid to 5 square grid was evaluated as "o", the case where the number of squares was 6 square grid to 9 square grid was evaluated as "Δ", and the case where the number of squares was 10 square grid to "x".

< Heat generating Property >

Using the prepared fixing member, the time until the surface temperature of the fixing member on the protective layer side reached 100 ℃ at the IH temperature rise (in the vicinity of the IH coil) was measured. The case where the arrival time was less than 5 seconds was evaluated as "very excellent", the case where the arrival time was 5 seconds or more and less than 10 seconds was evaluated as "o", the case where the arrival time was 10 seconds or more and less than 15 seconds was evaluated as "Δ", and the case where the arrival time was 15 seconds or more was evaluated as "x"

The fixing member of comparative example 1 was not provided with a protective layer on the metal layer. Therefore, in the durability test, a large number of cracks are generated in the metal layer due to repeated bending fatigue. In addition, the adhesion of the metal layer is poor. The fixing member of comparative example 2 had a metal layer on the entire surface of the base layer, and had no surface of the base layer not covered with the metal layer. Therefore, even if the protective layer is formed on the metal layer, the protective layer does not adhere to the base layer, and therefore the effect of improving the adhesion of the metal layer by the protective layer is low, and the adhesion of the metal layer is poor. In the fixing member of comparative example 3, since the protective layer is made of polyamide and the protective layer does not contain a resin containing an imide bond in a repeating unit, the adhesion between the base layer and the protective layer is poor, the effect of improving the adhesion of the metal layer by the protective layer is low, and the adhesion of the metal layer is poor, relative to the base layer made of polyimide.

In contrast, in the fixing member of the embodiment, the protective layer continuously covers the surface of the base layer not covered with the metal layer and the surface of the metal layer, and the metal layer is embedded between the base layer and the protective layer, so that the occurrence of cracks in the metal layer due to repeated bending fatigue can be suppressed, and the durability is excellent. Further, since the base layer and the protective layer each contain a resin containing an imide bond in a repeating unit and the protective layer is bonded to the base layer on the surface of the base layer not covered with the metal layer, the effect of improving the adhesion of the metal layer by the protective layer is high and the adhesion of the metal layer is excellent.

In addition, in the comparison of examples 1 to 5, when the thickness of the protective layer is 10 μm or more, the durability and the adhesion are more excellent, and when the thickness of the protective layer is 15 μm or more, the durability and the adhesion are further excellent. Further, the heat generating property is more excellent when the thickness of the protective layer is 50 μm or less, and the heat generating property is further excellent when the thickness of the protective layer is 30 μm or less. In addition, in the case of comparing examples 1 and 6 to 9, the adhesion was more excellent when the area ratio of the surface where the base layer and the protective layer were bonded was 20% or more, and the adhesion was further excellent when the area ratio was 30% or more. Further, if the area ratio is 20% or more and 75% or less, the durability is further excellent. When the area ratio is increased, the adhesion between the base layer and the protective layer is improved, and the durability is improved, while when the area ratio is increased, the metal layer becomes thinner (the line width becomes smaller), and the durability is reduced. Therefore, the area ratio is more excellent in durability at 75% than at 80%. When the area ratio is 75% or less, the heat generating property is further excellent. Further, when comparing examples 1, 10 to 13, the durability and heat generating property are more excellent when the thickness of the metal layer is in the range of 1.0 to 10 μm.

The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments at all, and various changes can be made without departing from the scope of the present invention.