JP2017015965A - Base material for fixing belt, fixing belt, fixing device, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base material for a fixing belt that is excellent in bending resistance, a fixing belt, a fixing device, and an image forming apparatus.SOLUTION: There is provided a base material 71 for a fixing belt that comprises a laminate 71A having a lamination of a plurality of metal layers and has flexibility, wherein the laminate 71A includes a nickel layer 71b that is formed of nickel, a copper layer 71c that is laminated on the nickel layer 71b and includes an alloy of copper and tin, and a protective layer 71d that is laminated on a surface of the copper layer 71c on the opposite side of a surface laminated on the nickel layer 71b and formed of nickel.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a fixing belt substrate, a fixing belt, a fixing device, and an image forming apparatus.

  An image forming apparatus that employs an electrophotographic system such as a copying machine, a printer, or a facsimile machine includes a fixing device that heats and fixes an unfixed toner image on a recording medium such as transfer paper or an OHP sheet. For the fixing device, a belt nip method has been widely used.

  In a belt nip type fixing device, a pressure roller urges a fixing belt that can be circulated and moved to a heating mechanism portion, and a nip portion is formed when the fixing belt and the pressure roller are pressed against each other. Are known. In such a fixing device, a pressure roller is brought into pressure contact with a heated fixing belt to form a nip portion, and an unfixed toner image is fixed on a recording medium passed through the nip portion.

  In the fixing device described above, the load applied to the fixing belt is large due to being accompanied by a rotating pressure roller, repeated bending strain due to formation of the nip portion, direct heating by a heating source, and the like. Therefore, metal materials such as stainless steel (SUS), nickel, aluminum, and copper having excellent strength are often used as the material for the fixing belt substrate. In particular, nickel is suitable for a fixing belt substrate because it has high strength and excellent durability, and can easily manufacture an endless belt. In addition, a technique for increasing the thermal conductivity of the entire fixing belt by laminating a copper layer having high thermal conductivity on nickel is known (see Patent Document 1).

  However, since the strength of the copper layer of the fixing belt described in Patent Document 1 is lower than that of the nickel layer, the fixing belt is subjected to bending and deformation during the production process, handling during shipping, and use in the market. Can cause unrecoverable folds and collapses.

  SUMMARY An advantage of some aspects of the invention is that it provides a fixing belt substrate, a fixing belt, a fixing device, and an image forming apparatus that are excellent in bending resistance.

  In order to solve the above-described problem, the fixing belt substrate of the invention according to claim 1 is a flexible fixing belt substrate that includes a laminate formed by laminating a plurality of metal layers, and has flexibility. The laminated body has a nickel layer made of nickel, a copper layer containing an alloy of copper and tin laminated on the nickel layer, and a surface of the copper layer opposite to the surface on which the nickel layer is laminated. And a protective layer made of nickel that is laminated.

  According to the fixing belt substrate according to claim 1, since the copper layer contains an alloy of copper and tin, the strength of the copper layer can be increased, and the thermal conductivity necessary as the fixing belt substrate. It is possible to suppress the occurrence of dent-like folds and crushing caused by the low strength of the copper layer while ensuring the above. Moreover, the oxidation of a copper layer can be suppressed by laminating | stacking the protective layer comprised with nickel on the copper layer.

1 is a schematic diagram illustrating an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a schematic configuration of a fixing device provided in the image forming apparatus. FIG. 3 is a cross-sectional view illustrating a pressure roller provided in the fixing device. FIG. 2 is an enlarged cross-sectional view illustrating a part of a fixing belt provided in the fixing device. It is a figure which shows an example of the manufacturing apparatus used for manufacture of the base material for fixing belts with which the said fixing belt is provided. 4 is a table (Table 1) showing the thickness of each layer of a fixing belt substrate used in Examples and Comparative Examples of the present invention. It is a table | surface (Table 2) which shows content of each component in the copper layer of the base material for fixing belts used for the said Example and comparative example. It is a table | surface (Table 3) which shows the composition of the copper- tin electroforming liquid used for preparation of the copper layer of the base material for fixing belts used for an Example. 6 is a table (Table 4) showing evaluation results of fixing belts of examples and comparative examples.

  An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram illustrating a printer 1 as an image forming apparatus according to the present embodiment. First, the overall configuration and operation of the printer 1 will be described with reference to FIG.

  The printer 1 uses four sets of electrophotographic systems to form toner images of four colors of yellow, magenta, cyan, and black on the surfaces of the corresponding photosensitive drums 1Y, 1M, 1C, and 1BK (image carrier). Image forming units 10Y, 10M, 10C, and 10BK (image forming means).

  Below these image forming units 10Y, 10M, 10C, and 10BK, a conveyance belt 20 for conveying the sheet S through each image forming unit is stretched. Here, the sheet S is, for example, paper such as transfer paper or recording paper (including thick paper, postcard, envelope, plain paper, thin paper, etc.), coated paper (including coated paper, art paper, etc.), OHP sheet or It means an image forming medium capable of transferring an image, including an OHP film, tracing paper, and the like.

  The photosensitive drums 1Y, 1M, 1C, and 1BK of the image forming units 10Y, 10M, 10C, and 10BK are arranged in rolling contact with the conveyance belt 20, and the sheet S is electrostatically attracted to the surface of the conveyance belt 20. .

  The four sets of image forming units 10Y, 10M, 10C, and 10BK have substantially the same structure. Therefore, here, the yellow image forming unit 10Y disposed on the most upstream side in the conveyance direction X of the sheet S will be described as a representative, and the image forming units 10M, 10C, and 10BK for other colors are color-identified. For this reason, the same reference numerals are used except for the reference numerals Y, M, C, and BK, and detailed description thereof is omitted.

  The image forming unit 10Y has a photosensitive drum 1Y that is in contact with the conveyance belt 20 at a substantially central position. Around the photosensitive drum 1Y, a charging device 2Y for charging the surface of the photosensitive drum 1Y to a predetermined potential, and the charged drum surface is exposed based on the color-separated image signal, and the drum surface is electrostatically charged. An exposure device 3Y that forms a latent image, a developing device 4Y that supplies yellow toner to the electrostatic latent image formed on the drum surface and develops the sheet, and a sheet that conveys the developed toner image via the conveyance belt 20 A transfer roller 5Y for transferring onto S, a cleaner 6Y for removing residual toner remaining on the drum surface without being transferred, and an appropriate charge-removing lamp for removing electric charge remaining on the drum surface are provided on the photosensitive drum 1Y. They are arranged in order along the rotation direction.

  A sheet feeding mechanism 30 for feeding the sheet S onto the conveying belt 20 is disposed on the right side of the conveying belt 20 in the drawing. The sheet S fed from the paper feed mechanism 30 is transported in the direction of arrow X by the transport belt 20 and is sequentially toner images of each color of 10Y, 10M, 10C, and 10BK by the image forming units 10Y, 10M, 10C, and 10BK. Are stacked on the surface, and an unfixed full-color toner image T is formed.

  A fixing device 40 according to an embodiment of the present invention, which will be described later, is disposed on the left side of the conveyance belt 20 in the drawing (excitation coils and the like are omitted in the drawing). The sheet S conveyed by the conveyance belt 20 is conveyed to a conveyance path continuously extending from the conveyance belt 20 through the fixing device 40 and passes through the fixing device 40.

  The fixing device 40 heats and pressurizes the conveyed sheet S, that is, the sheet S on which the full-color toner image T is transferred. Then, the full-color toner image T is melted and permeated into the sheet S to be fixed. Further, the fixing device 40 discharges to the downstream side in the transport direction X via a paper discharge roller.

  Next, the fixing device 40 will be described with reference to FIGS. FIG. 2 is a diagram illustrating a schematic configuration of the entire fixing device 40. FIG. 3 is a cross-sectional view showing the pressure roller 42 constituting the fixing device 40.

  As shown in FIG. 2, the fixing device 40 includes a heating mechanism 41 and a pressure roller 42. The fixing device 40 sandwiches the sheet S at a nip portion N formed between the fixing belt 7 and the pressure roller 42 of the heating mechanism unit 41, and applies heat and pressure when the sheet S passes through, so that the toner image T is fixed to the sheet S.

  The heating mechanism 41 heats the sheet S and is arranged extending in a direction orthogonal to the transport direction X (a direction orthogonal to the paper surface of FIG. 2). The heating mechanism unit 41 includes a reinforcing member 43, a nip forming member 44, a heat source 45, and a fixing belt 7 that is formed in an endless shape by arranging these members on the inside. The fixing belt 7 is provided so as to be able to circulate in the direction of arrow A in FIG. Further, the fixing belt 7 is arranged so that the width direction thereof is orthogonal to the conveying direction X (perpendicular to the paper surface of FIG. 2). The fixing belt 7 will be described in detail later.

  The reinforcing member 43 is for reinforcing and supporting the nip forming member 44 that forms the nip portion N between the fixing belt 7 and the pressure roller 42, and the nip forming member 44 by the pressure applied by the pressure roller 42. Deformation and displacement are suppressed. The reinforcing member 43 supports the fixing belt 7 so as to be able to circulate. The reinforcing member 43 is a substantially triangular prism-like member provided so as to extend in a direction orthogonal to the conveyance path, and one side surface is arranged in parallel with the surface of the conveyance belt 20 and covers the upper surface of the nip forming member 44 from the side surface. A flange is formed as described above. The fixing belt 7 is shaped into a substantially cylindrical shape by the shape of the reinforcing member 43 and the circulation movement thereof is guided. In order to satisfy such a function, the reinforcing member 43 is preferably formed of a metal material having high mechanical strength such as stainless steel or iron.

  The nip forming member 44 presses the pressure roller 42 via the fixing belt 7 to form a nip portion N between the pressure roller 42 and the fixing belt 7, and is a rigid body made of a metal material. Part, an elastic part made of a rubber material, a rigid part, and a lubricating sheet covering the elastic part. The rigid body portion is preferably formed of a highly rigid metal, ceramic, or the like so as to withstand the pressure applied by the pressure roller 42. The elastic portion is formed in a concave shape so that the surface on the pressure roller 42 side follows the curvature of the pressure roller 42, so that a sufficient width of the nip portion N is ensured so as to cope with high speed. It has become.

  The heat source 45 is for heating the fixing belt 7. The heat source 45 heats the fixing belt 7 when the circulatingly moving fixing belt 7 passes in the vicinity of the heat source 45 and heats the entire fixing belt 7.

  Next, the pressure roller 42 will be described with reference to FIGS. The pressure roller 42 applies pressure to the sheet S, and is pressed toward the nip forming member 44 side (the upper side in FIG. 2) by an appropriate elastic body such as a spring. The forming member 44 is pressed to form the nip portion N. The pressure roller 42 is rotationally driven by an appropriate drive motor, and the rotation direction is indicated by an arrow B direction in FIG. Further, the pressure roller 42 is arranged so that its axis is parallel to the width direction of the fixing belt 7 (direction perpendicular to the paper surface of FIG. 2).

  The pressure roller 42 has a structure in which a foamed elastic layer 47, a solid elastic layer 48, and a release layer 49 are laminated in this order on a metal core 46 made of a metal cylindrical member. An appropriate grip layer for securing a frictional force is provided outside the sheet passing area at both ends of the pressure roller 42 in order to contact and follow the fixing belt 7.

  The foamed elastic layer 47 is a layer made of a foamed elastic body having open cells and is excellent in heat insulation. For this reason, when heating the nip portion N, it is difficult to absorb the heat of the fixing belt 7, and the time required for fixing can be shortened. The solid elastic layer 48 is formed on the foamed elastic layer 47. By setting the thickness of the solid elastic layer 48 to 0.2 mm or more and 2 mm or less, it is possible to obtain anti-foaming resistance and high adhesive strength in the vicinity of the core metal. The material of the solid elastic layer is preferably silicone rubber in consideration of heat resistance.

  As the release layer 49, for example, a fluorine resin can be used in consideration of heat resistance and prevention of toner adhesion. Examples of such a fluorine-based resin include tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer resin (PFA) and tetrafluoroethylene resin (PTFE).

  Next, the fixing belt 7 according to this embodiment will be described in detail with reference to FIG. FIG. 4 is an enlarged cross-sectional view showing a part of the fixing belt 7. As shown in FIG. 4, the fixing belt 7 according to the present embodiment includes an endless fixing belt substrate 71, an elastic layer 72 formed on the outer peripheral surface of the fixing belt substrate 71, and elasticity. A release layer 73 formed on the outer peripheral surface of the layer 72 and a sliding layer 74 formed on the inner peripheral surface of the fixing belt substrate 71 are provided.

  The fixing belt substrate 71 includes a laminated body 71A formed by laminating a plurality of metal layers, and is configured to have flexibility. The laminated body 71A preferably has a thickness of 20 μm or more and 50 μm or less. The stacked body 71A includes a nickel layer 71b, a copper layer 71c stacked on the nickel layer 71b, and a protective layer 71d stacked on the copper layer 71c. The nickel layer 71b is made of nickel, but may contain other substances such as phosphorus, sulfur, and carbon, and may be a nickel alloy. As content of nickel contained in the nickel layer 71b, it is preferable that it is 99.0 mass% or more and 99.9 mass% or less, and it is more preferable that it is 99.2 mass% or more and 99.6 mass% or less. When the nickel layer 71b contains phosphorus, the phosphorus content is preferably 0.4% by mass or more and 0.7% by mass or less. When the nickel layer 71b contains sulfur, the sulfur content is 0%. It is preferable that it is 0.003 mass% or more and 0.02 mass% or less, and when it contains carbon, it is preferable that carbon content is 0.012 mass% or more and 0.03 mass% or less.

  The thickness of the nickel layer 71b is preferably not less than 0.5 μm and not more than 5 μm, and more preferably not less than 1 μm and not more than 3 μm. With such a configuration, the strength required for the fixing belt substrate 71 can be obtained.

  The copper layer 71c is formed including an alloy of copper and tin, and is laminated on the nickel layer 71b. Moreover, the copper layer 71c is formed thicker than the nickel layer 71b, and the tensile elastic modulus is configured to be 40 GPa or more.

  The ratio of the mass of the copper and tin alloy to the total mass of the copper layer 71c is preferably 0.3% by mass or more and 5.0% by mass or less, and more preferably 0.5% by mass or more and 4.0% by mass or less. It is more preferable. With such a configuration, the strength of the copper layer 71c can be further increased.

The copper layer 71c may contain other substances such as sulfuric acid and chlorine. The content of copper contained in the copper layer 71c is preferably 95% by mass or more and 99.7% by mass or less,
More preferably, it is 96 mass% or more and 99.5 mass% or less. In addition, when the copper layer 71c contains sulfur, the sulfur content is preferably 0.003% by mass or more and 0.01% by mass or less. When the copper layer 71c contains chlorine, the chlorine content is 0. It is preferable that it is 0.001 mass% or more and 0.002 mass% or less.

  The thickness of the copper layer 71c is preferably 20 μm or more and 45 μm or less, and more preferably 25 μm or more and 40 μm or less. With such a configuration, the fixing belt substrate 71 having excellent thermal conductivity can be obtained while ensuring the strength required for the fixing belt substrate 71.

  The protective layer 71d is laminated on the surface of the copper layer 71c opposite to the surface on which the nickel layer 71b is laminated. The protective layer 71d has the same composition as the nickel layer 71b, and the thickness of the protective layer 71d is preferably not less than 0.5 μm and not more than 5 μm, and more preferably not less than 1 μm and not more than 3 μm. With such a configuration, the copper layer 71c can be protected from being oxidized.

  The elastic layer 72 is laminated on the outer peripheral surface of the fixing belt substrate 71, that is, on the protective layer 71d of the laminated body 71A. The elastic layer 72 is provided for the purpose of giving flexibility to the belt surface in order to obtain a uniform image without uneven gloss. In order to achieve such an object, the elastic layer 72 is preferably made of a material having elasticity such as rubber, and is made of silicone rubber, fluorosilicone rubber or the like from the viewpoint of heat resistance at the fixing temperature. Is preferred. The rubber hardness is preferably 5 ° to 50 ° (JIS-A), and the thickness is preferably 50 µm to 500 µm, more preferably 100 µm to 200 µm.

  The release layer 73 is laminated on the outer peripheral surface of the elastic layer 72, that is, the surface opposite to the laminated body 71 </ b> A of the elastic layer 72. The release layer 73 is provided for the purpose of preventing toner and other dirt from adhering to the surface of the fixing belt 7 and maintaining the function of the fixing belt 7. Examples of the material of the release layer 73 include a fluorine resin, a mixture of these resins, and a material in which these fluorine resins are dispersed in a heat resistant resin. Examples of the fluororesin include PTFE, PFA, and tetrafluoroethylene / hexafluoropropylene copolymer (FEP).

  In order to achieve both mold release properties and flexibility, the thickness of the release layer 73 is preferably 5 μm or more and 50 μm or less, and more preferably 10 μm or more and 30 μm or less.

  As shown in FIG. 2, the sliding layer 74 is a layer in contact with the nip forming member 44, and is provided for the purpose of facilitating the rotation of the fixing belt 7 following the movement of the sheet S and the pressure roller 42. Yes. The sliding layer 74 is formed by laminating, for example, a layer made of polyimide or PFA having good sliding properties on the inner peripheral surface of the fixing belt substrate 71 so that the thickness is 5 μm or more and 30 μm or less. To do. If the thickness of the sliding layer 74 is too thin, the substrate may be exposed in a relatively short time due to wear and durability may be insufficient. If it is too thick, the heat transfer performance for fixing the toner image T is deteriorated and fixing is performed. It may become defective. A more preferable thickness is 10 μm or more and 20 μm or less.

  Next, an example of a method for manufacturing the fixing belt substrate 71 and a method for manufacturing the fixing belt 7 will be described. FIG. 5 is a diagram illustrating an example of a manufacturing apparatus used for manufacturing the fixing belt substrate 71. A manufacturing apparatus 80 shown in FIG. 5 includes a liquid tank 81 and an electroforming tank 82. An electroforming solution 83 is accommodated in the liquid tank 81.

  The electroforming tank 82 is connected to an electroforming liquid jet pipe 84 at the bottom thereof, and the electroforming liquid 83 in the liquid tank 81 passes through an appropriate liquid feed pump from the electroforming liquid jet pipe 84 into the electroforming tank 82. Has been supplied to. The electroforming tank 82 has an overflow portion 81a. The electroforming liquid 83 is circulated in the order of the liquid tank 81, the electroforming liquid ejection pipe 84, the electroforming tank 82, the overflow portion 81 a, and the liquid tank 81.

  In addition, two anode electrodes 85 are disposed in the electroforming tank 82, and a cylindrical electroforming mother mold 86 (also used as a cathode electrode) is disposed in the center thereof. As the material of the electroforming mold 86, a metal that can be energized can be used, but considering that it is attacked by the electroforming solution 83, it is preferable to use stainless steel. The electroforming mother die 86 is rotatable around the axis of the cylinder so that the entire thickness of the fixing belt substrate 71 to be manufactured is uniform, and an appropriate drive mechanism is used during electroforming. It is rotationally driven by.

  In order to obtain the copper layer 71 c by electroforming using the manufacturing apparatus 80, a copper-tin electroforming liquid is used as the electroforming liquid 83. On the other hand, in order to obtain the nickel layer 71b and the protective layer 71d, a nickel electroforming liquid is used as the electroforming liquid 83.

  As the copper-tin electroforming liquid, various electroforming liquids generally used in this field can be used, and electroforming composed of copper (II) pyrophosphate, tin (II) diphosphate and potassium pyrophosphate. It is preferable to use a liquid.

  As a copper-tin electroforming liquid, it is preferable that the ratio (henceforth P ratio) of the pyrophosphoric acid with respect to the tin and copper contained in a copper-tin electroforming liquid is 8-20, Preferably it is 8-10. It is more preferable that If the P ratio is less than 8, copper or tin forms an insoluble complex salt, and normal plating (copper layer 71c) is difficult to obtain. On the other hand, if the P ratio exceeds 20, that is, if the amount of potassium pyrophosphate is large, the current efficiency is lowered, which is not practical. In addition, P ratio is calculated | required with the following formula | equation.

  P ratio = [(Amount of pyrophosphate atom / Atom weight of potassium pyrophosphate) × Potassium pyrophosphate concentration (g / L) + (Amount of pyrophosphate atom / Amount of tin (II) diphosphate) × Tin (II) diphosphate concentration (g / L) + (atomic weight of pyrophosphate / copper (II) pyrophosphate) × concentration of copper (II) pyrophosphate (g / L)] / [(atomic weight of tin / atomic weight of tin (II) diphosphate) × diphosphoric acid Tin (II) concentration (g / L) + (copper atomic weight / copper pyrophosphate (II) atomic weight) × copper pyrophosphate (II) concentration (g / L)]

  Specifically, the copper-tin electroforming solution contains copper (II) pyrophosphate in an amount of 20 g / L to 60 g / L, preferably about 45 g / L to 55 g / L, and tin (II) diphosphate. 1 g / L or more and 10 g / L or less, preferably about 3 g / L or more and 6 g / L or less, and potassium pyrophosphate is 0 g / L or more and 500 g / L or less, preferably about 200 g / L or more and 300 g / L or less. What was contained is mentioned. Moreover, what contains about 20 g / L or more and 40 g / L or less of ammonium oxalate other than the above is mentioned.

  In addition to the above, the copper-tin electroforming liquid includes 3,3′-dithiobis (1) as a pH brightener such as polyphosphoric acid and aqueous ammonia, and as a primary brightener for smoothing and crystal refining. -Propanesulfonic acid) Disodium, polydiallyldimethylammonium chloride as leveling agent, 2-mercaptobenzimidazole-5-sulfonic acid sodium salt, hydrochloric acid, etc. are added as tensile modulus improvement and recrystallization inhibitor at high temperature be able to. The pH of the copper-tin electroforming liquid is preferably 8.0 or more and 9.5 or less.

Manufacturing conditions such as a current value and an electroforming time in the manufacturing apparatus 80 when performing copper-tin alloy electroforming are set for each surface area of the master die depending on the current density, and the current density is 1 A / dm ² or more and 6 A / dm ^2. It is preferable that it is about the following.

  As the nickel electroforming liquid, various electroforming liquids generally used in the field can be used, but it is preferable to use a nickel sulfamate electroforming liquid, and further, a phosphorus-containing component, a chlorine-containing component, and a sulfur-containing component. It is preferable that a component and a carbon-containing component are included. In addition, nickel sulfamate electroforming liquids include pH buffering agents such as boric acid, formic acid, and nickel acetate, as well as brighteners and pits for the purpose of smoothing, preventing pits, refining crystals, reducing residual stress, etc. An inhibitor, an internal stress reducing agent, and the like can be added. Examples of the nickel sulfamate electroforming solution include nickel sulfamate tetrahydrate of 300 g / L to 600 g / L, nickel chloride of 0 g / L to 30 g / L, and boric acid of 20 g / L to 40 g / L. And those containing an appropriate amount of primary brightener, secondary brightener and the like. The pH of the nickel electroforming solution is preferably 3.5 or more and 4.5 or less.

Manufacturing conditions in the manufacturing apparatus 80, such as a current value and electroforming time when performing nickel electroforming, are set for each surface area of the matrix depending on current density. Current density is preferably about 1~14A / dm ^2.

  Next, a manufacturing procedure using the manufacturing apparatus 80 will be described. After cleaning the surface of the electroforming mold 86, the electroforming mold 86 is immersed in the electroforming tank 82 of FIG. 5 filled with the nickel electroforming liquid as the electroforming liquid 83, and electroforming is started. After the elapse of time when the nickel electroformed film formed by electroforming has a desired thickness of the nickel layer, the electroforming is finished, the electroforming mother mold 86 is pulled up from the electroforming tank 82, and the formed nickel layer The surface of 71b is washed with water.

  Thereafter, the electroforming mother mold 86 on which the nickel layer 71b is formed is immersed in the electroforming tank 82 of FIG. 5 filled with the copper-tin electroforming liquid as the electroforming liquid 83, and electroforming is started. After the elapse of time when the copper electroformed film formed by electroforming has a desired thickness of the copper layer, the electroforming is finished, and the electroforming mother mold 86 is pulled up from the electroforming tank 82, and the formed copper layer The surface of 71c is washed with water.

  Thereafter, in the electroforming tank of FIG. 5 again, the protective layer 71d is formed on the electroforming mother die 86 using the nickel electroforming liquid as described above. The obtained laminate 71A composed of the nickel layer 71b, the copper layer 71c, and the protective layer 71d is pulled up from the electroforming tank 82 together with the electroforming mother mold 86, and after being washed with water, is immersed in cooling water for the purpose of heat shrinkage. And cooled to 10 ° C. or lower. Next, high-pressure water is sprayed on the interface between the electroforming mother mold 86 and the laminated body 71A to form a gap between the electroforming mother mold 86 and the laminated body 71A. The laminated body 71A is removed from the electroformed mother mold 86 by moving the electroformed mother mold 86 relatively in the axial direction while holding the end of the laminated body 71A in which the gap is formed. An endless fixing belt substrate 71 is obtained by cutting off both ends of the laminate 71A thus obtained to a predetermined length.

  Using the fixing belt substrate 71 obtained as described above, a sliding layer 74 is formed on its inner peripheral surface, and an elastic layer 72 and a release layer 73 are formed on its outer peripheral surface by a known method, and fixing. A belt 7 is obtained. Here, the performance required for the fixing belt substrate 71 includes durability when the fixing belt 7 is configured, flexibility, and heat resistance that can withstand use at the fixing temperature. The mold layer and the like are also formed so as to satisfy these performances.

  According to the fixing belt substrate 71 according to the present embodiment, since the copper layer 71c of the laminated body 71A contains an alloy of copper and tin, the strength of the copper layer 71c can be increased. Therefore, the fixing belt substrate 71 according to the present embodiment generates dents and collapses due to the low strength of the copper layer 71c while ensuring the thermal conductivity required for the fixing belt substrate 71. And is excellent in bending resistance.

  Moreover, according to the fixing belt substrate 71 according to the present embodiment, since the protective layer 71d made of nickel is laminated on the copper layer 71c, the oxidation of the copper layer 71c can be suppressed.

  Further, according to the fixing belt substrate 71 according to the present embodiment, when the thickness of the laminated body 71A is set to 20 μm or more and 50 μm or less, the occurrence of a dent-like fold or crush is suppressed, and the fixing excellent in bending resistance. It can be set as the base material for belts. If the thickness of the laminated body 71A is less than 20 μm, the strength may be slightly inferior. On the other hand, when the thickness of the fixing belt substrate 71 exceeds 50 μm, the start-up time in the fixing device and the image forming apparatus provided with the fixing belt substrate 71 increases. The thickness of the stacked body 71A is more preferably 25 μm or more and 45 μm or less, and further preferably 30 μm or more and 40 μm or less. With such a configuration, the fixing belt substrate 71 having excellent strength and heat conductivity can be obtained.

  Further, according to the fixing belt substrate 71 according to the present embodiment, since the copper layer 71c of the laminate 71A is formed thicker than the nickel layer 71b, the fixing belt substrate 71A can be prevented from being broken or crushed. The thermal conductivity as the base material 71 can be increased.

  In addition, according to the fixing belt substrate 71 according to the present embodiment, the copper layer 71c of the laminate 71A has a tensile elastic modulus of 40 GPa or more, and therefore, the occurrence of bending or crushing caused by insufficient strength of the copper layer 71c. Can be suppressed. If the tensile elastic modulus of the copper layer 71c is less than 40 GPa, the strength of the copper layer 71c may be slightly inferior.

  In addition, since the fixing belt 7 according to the present embodiment includes the fixing belt base material 71, it is possible to suppress the occurrence of a dent-like crease or crush while ensuring thermal conductivity.

  In addition, the fixing device 40 according to the present embodiment and the printer 1 including the fixing device 40 are provided with the fixing belt 7 that has excellent anti-bending properties and can withstand a high-load use environment. It is possible to meet demands and form images stably for a long period of time. Further, since the fixing belt 7 having a high thermal conductivity is provided, the start-up time is short, and the energy saving performance when the printer 1 and the fixing device 40 are started up is excellent.

  In addition, embodiment mentioned above only showed the typical form of this invention, and this invention is not limited to the said embodiment. That is, those skilled in the art can implement various modifications in accordance with conventionally known knowledge without departing from the scope of the present invention. Of course, such modifications are also included in the scope of the present invention as long as they have the configurations of the fixing belt substrate, the fixing belt, the fixing device, and the image forming apparatus of the present invention.

  For example, in the above-described embodiment, the thickness of the stacked body 71A is 20 μm or more and 50 μm or less, but the present invention is not limited to this as long as the occurrence of a dent-like fold or crush can be suppressed.

  Moreover, in the said embodiment, although the tensile elasticity modulus of the copper layer 71c was 40 GPa or more, if generation | occurrence | production of a dent-like fold and a collapse can be suppressed, it will not be limited to this.

  In the above-described embodiment, the laminated body 71A includes the nickel layer 71b, the copper layer 71c, and the protective layer 71d, and forms the fixing belt substrate 71. However, the present invention is not limited thereto. The fixing belt substrate 71 may include other layers. For example, another layer may be laminated on the surface of the nickel layer 71b opposite to the copper layer 71c, and another layer may be laminated on the surface of the protective layer 71d opposite to the copper layer 71c.

  In the above embodiment, the fixing belt 7 has an endless fixing belt substrate 71, an elastic layer 72 formed on the outer peripheral surface of the fixing belt substrate 71, and an outer periphery of the elastic layer 72. Although the release layer 73 formed on the surface and the sliding layer 74 formed on the inner peripheral surface of the fixing belt substrate 71 are provided, the configuration is not limited thereto. For example, another layer may be formed between the elastic layer 72 and the release layer 73 or between the fixing belt substrate 71. Moreover, you may provide a primer layer between each layer as needed.

  Examples of the present invention are shown below. In addition, the thicknesses of the nickel layer, the copper layer, and the protective layer of the base material for the fixing belt used for the fixing belts of Examples 1 to 6 and Comparative Examples 1 to 3 to be produced are shown in Table 1 in FIG. Moreover, content (mass%) of tin with respect to the mass of the whole copper layer in a copper layer, content (mass%) of sulfur, and content (mass%) of chlorine are shown in (Table 2) of FIG. In (Table 1) and (Table 2), the parentheses indicate units.

[Fixing Belt Substrate Used in Example 1]
(1. Preparation of nickel layer)
In the manufacturing apparatus shown in FIG. 5, nickel electroforming was performed using a stainless steel electroforming mother mold having a body diameter of 30 mm and a length of 460 mm. A nickel sulfamate electroforming liquid was used as the nickel electroforming liquid. The composition of the nickel sulfamate electroforming solution is nickel sulfamate tetrahydrate 525 g / L and boric acid 33 g / L, and contains appropriate amounts of primary brightener and secondary brightener. The temperature of the nickel electroforming solution during electroforming was adjusted to 55 ± 3 ° C., and while rotating the electroforming mold, nickel electroforming was performed with a current density of 4 A / dm ² , and a nickel layer with a thickness of 1 μm was formed. Formed. Thereafter, the electroforming mother mold having a nickel layer formed on the surface was pulled up from the electroforming tank and washed with water.

(2. Preparation of copper layer)
Subsequently, copper electroforming was performed. The composition of the copper-tin electroforming liquid is as shown in (Table 3) of FIG. The temperature of the copper-tin electroforming solution during electroforming is adjusted to 45 ± 3 ° C., and the electroforming is performed at a current density of 1 A / dm ² while rotating the mother die to form a copper layer having a thickness of 28 μm. did. The electroforming mother mold having a copper layer laminated on the surface was pulled up from the electroforming tank and washed with water.

(3. Preparation of protective layer)
Next, a nickel layer having a thickness of 1 μm is laminated on the outermost surface in the same manner as described above (1. Preparation of nickel layer), and after removing from the electroforming mother mold and cleaning, both ends are adjusted so that the total length becomes 360 mm. The base material for fixing belts used for Example 1 provided with the laminated body of the three-layer structure of the protective layer comprised with the nickel layer, the copper layer, and nickel was obtained.

[Fixing Belt Substrate Used in Example 2]
A fixing belt substrate used in Example 2 was prepared under the same conditions as in Example 1 except that the thickness of the copper layer was 38 μm in Example 2 (2. Production of copper layer). did.

[Fixing Belt Substrate Used in Examples 3 to 5]
(1. Preparation of nickel layer)
In the manufacturing apparatus shown in FIG. 5, nickel electroforming was performed under the same conditions as in Example 1 to form a nickel layer having a thickness of 1 μm. As the nickel electroforming liquid, the same nickel sulfamate electroforming liquid as in Example 1 was used. Thereafter, the electroforming mother mold having a nickel layer formed on the surface was pulled up from the electroforming tank and washed with water.

(2. Preparation of copper layer)
Subsequently, copper electroforming was performed. The composition of the copper-tin electroforming liquid is as shown in (Table 3) of FIG. The temperature of the copper-tin electroforming solution during electroforming is adjusted to 45 ± 3 ° C., and the electroforming is performed with the current density of 1 A / dm ² while rotating the matrix, forming a copper layer with a thickness of 38 μm. did. The electroforming mother mold having a copper layer laminated on the surface was pulled up from the electroforming tank and washed with water.

(3. Preparation of protective layer)
Next, a nickel layer having a thickness of 1 μm is laminated on the outermost surface in the same manner as described above (1. Preparation of nickel layer), and the fixing belt substrate used in Examples 3 to 5 is used as in Example 1. Obtained.

[Fixing Belt Substrate Used in Example 6]
(1. Preparation of nickel layer)
In the manufacturing apparatus shown in FIG. 5, nickel electroforming was performed under the same conditions as in Example 1 to form a nickel layer having a thickness of 1 μm. As the nickel electroforming liquid, the same nickel sulfamate electroforming liquid as in Example 1 was used. Thereafter, the electroforming mother mold having a nickel layer formed on the surface was pulled up from the electroforming tank and washed with water.

(2. Preparation of copper layer)
Subsequently, copper electroforming was performed. The composition of the copper-tin electroforming liquid is as shown in (Table 3) of FIG. In the Examples 2-5 (2. Preparation of the copper layer) was formed a copper layer under the same conditions as in Example 2-5 except that the so current density of 3A / dm ^2. The electroforming mother mold having a copper layer laminated on the surface was pulled up from the electroforming tank and washed with water.

(3. Preparation of protective layer)
Next, a nickel layer having a thickness of 1 μm was laminated on the outermost surface by the same method as described above (1. Preparation of nickel layer) to obtain a fixing belt substrate used in Example 6 as in Example 1. .

  As shown in Table 2, the copper layers in the fixing belt base materials used in Examples 1 to 6 have different contents of tin, sulfur and chlorine. This is adjusted by changing the composition of the copper-tin electroforming solution as shown in (Table 3).

[Fixing Belt Substrate Used in Comparative Example 1]
(1. Preparation of nickel layer)
In the manufacturing apparatus shown in FIG. 5, nickel electroforming was performed under the same conditions as in Example 1 to form a nickel layer having a thickness of 29 μm. As the nickel electroforming liquid, the same nickel sulfamate electroforming liquid as in Example 1 was used. Thereafter, the electroforming mother mold having a nickel layer formed on the surface was pulled up from the electroforming tank and washed with water.

(2. Preparation of copper layer)
Subsequently, copper electroforming was performed. The composition of the copper electroforming solution is copper (II) sulfate pentahydrate 80 g / L and sulfuric acid 200 g / L. The temperature of the copper electroforming liquid at the time of electroforming was adjusted to 55 ± 3 ° C., and electroforming was performed at a current density of 4 A / dm ² while rotating the mother die to form a 10 μm thick copper layer. The electroforming mother mold having a copper layer laminated on the surface was pulled up from the electroforming tank and washed with water.

(3. Preparation of protective layer)
Next, a nickel layer having a thickness of 1 μm was laminated on the outermost surface in the same manner as described above (1. Preparation of nickel layer) to obtain a fixing belt substrate used in Comparative Example 1 as in Example 1. .

[Fixing Belt Substrate Used in Comparative Example 2]
A fixing belt substrate used in Comparative Example 2 was prepared under the same conditions as in Comparative Example 1 except that the thickness of the copper layer was 20 μm in Comparative Example 1 (2. Production of copper layer). did.

[Fixing Belt Substrate Used in Comparative Example 3]
(1. Preparation of nickel layer)
In the manufacturing apparatus shown in FIG. 5, nickel electroforming was performed under the same conditions as in Example 1 to form a nickel layer having a thickness of 1 μm. The same nickel sulfamate electroforming solution as in Comparative Example 1 was used as the nickel electroforming solution. Thereafter, the electroforming mother mold having a nickel layer formed on the surface was pulled up from the electroforming tank and washed with water.

(2. Production of copper layer)
Subsequently, copper electroforming was performed. Copper electroforming was performed under the same conditions as in Comparative Example 1 to form a copper layer having a thickness of 18 μm. The same copper sulfate electroforming solution as in Comparative Example 1 was used as the copper electroforming solution. Thereafter, the electroforming mother mold having a copper layer formed on the surface was pulled up from the electroforming tank and washed with water.

(3. Preparation of protective layer)
Next, a nickel layer having a thickness of 1 μm was laminated on the outermost surface in the same manner as in (1. Preparation of nickel layer) to obtain a fixing belt substrate used in Comparative Example 3.

[Production of Examples and Comparative Examples]
As shown in FIG. 4, using the fixing belt substrate used in the above-described Examples and Comparative Examples, a sliding layer is provided on the inner peripheral surface, an elastic layer and a release layer are provided on the outer peripheral surface in this order. Formed. Specifically, first, in order to absorb the radiant heat from a halogen heater as a heat source, carbon black is blended and dispersed in PTFE, and the inner peripheral surface of the fixing belt substrate is then spray-coated. Thus, a 15 μm-thick sliding layer made of a black PTFE film was formed. Next, an elastic layer having a thickness of 120 μm was formed by forming silicone rubber (manufactured by Dow Corning Toray) on the outer peripheral surface of the fixing belt substrate by spray coating. Next, a pure and diluted primer (manufactured by Toray Dow Corning) was applied, and a 10 μm thick PFA tube (manufactured by Kurabo Industries) was further coated as a release layer, and dried at 200 ° C. for 30 minutes. Finally, the fixing belts of Examples 1 to 6 and Comparative Examples 1 to 3 were obtained by cutting both ends so that the total length was 350 mm.

  About the said Examples 1-6 and Comparative Examples 1-3, 1000 each was evaluated about the folding and the crushing which arise in the case of handling at the time of an inspection, etc., and in the case of packing before shipment. After the evaluation, the start-up time and the rate of occurrence of breakage or crushing were evaluated using a fixing belt that did not break or crush. The evaluation method will be described below.

[Evaluation of occurrence rate of breakage and crushing]
In the fixing unit, Examples 1 to 6 and Comparative Examples 1 to 3 after the evaluation were set in a fixing unit of a copying machine RICOH MPC4503 manufactured by Ricoh, and 10,000 sheets were passed. Next, each fixing belt was removed from the fixing unit, and the occurrence of breakage or crushing was visually evaluated. And about the processus | protrusion of about 10 micrometers-20 micrometers, and the fixing belt in which the unrecoverable bending trace and bending deformation | transformation were confirmed, it determined that the folding and the crushing had generate | occur | produced, and calculated the incidence. The results are shown in (Table 4) of FIG.

[Startup time evaluation]
In the above [Evaluation of occurrence rate of breakage and crushing], the time required until the temperature of the fixing belts of Examples 1 to 6 and Comparative Examples 1 to 3 when the power of the fixing unit is turned on can be measured was measured. The results are shown in (Table 4) of FIG.

  Moreover, the tensile elasticity modulus of the copper layer in the base material for fixing belts used for Examples 1-6 and Comparative Examples 1-3 was measured. The measurement method will be described below.

[Tensile modulus measurement]
The tensile elastic modulus of the copper layer of Examples 1-6 and Comparative Examples 1-3 was measured. The measurement is made of a nickel layer having a thickness of 1 μm, and a copper layer having a thickness of 30 μm is laminated thereon, and a sample of the copper layer of the base material for fixing belt used in Examples 1 to 6 and Comparative Examples 1 to 3 Got. Each sample was produced in the same manner as the production method of the fixing belt substrate used in Examples 1 to 6 and Comparative Examples 1 to 3. Using the samples obtained as described above, the tensile elastic moduli of the copper layers of Examples 1 to 6 and Comparative Examples 1 to 3 were measured.

  The tensile modulus was measured according to JIS Z 2241 metal material tensile test method using Autograph AGS-5KNX (manufactured by Shimadzu Corporation). The tensile direction was the belt circumferential direction, and the test was performed at 200 ° C. at a tensile speed of 10 mm / min. The range of acquisition of the tensile modulus is 45 to 60 N load, and the data values in the section are averaged by the least square method. The results are shown in (Table 4) of FIG.

  In (Table 4), the parentheses indicate units. Furthermore, those with a startup time of 6 seconds or less are accepted, those with a startup time exceeding 6 seconds are rejected, those with an occurrence rate of breakage or crushing of 1% or less are accepted, those with more than 1% are rejected, As a comprehensive evaluation, ○ marks were given to those that passed both the start-up time and the occurrence rate of breakage and crushing, and X marks were given to those that passed only one or both failed (Table 4).

  Regarding Comparative Example 3, since the thickness of the base material for the fixing belt was 20 μm or less, abnormal noise was generated from the fixing unit when 10,000 sheets were passed from the start of the test. The surface layer was in a cracked state, and as a result of peeling off each layer of the laminate, cracks in the copper layer were confirmed. Therefore, the evaluation of the occurrence rate of breakage and crushing was interrupted.

  As shown in (Table 4), with respect to Examples 1 to 6, the occurrence rate of folding was lower than those of Comparative Examples 1 and 2. In addition, it was found that the example had a shorter start-up time than the comparative example, and was excellent in energy saving when the image forming apparatus was started up. As for Comparative Example 1, the tensile modulus of the copper layer was low and the rate of occurrence of bending was high. For Comparative Example 2, the startup time increased when the total thickness was 50 μm or more, together with the fold generation rate.

1 Printer (image forming device)
40 Fixing Device 7 Fixing Belt 71 Fixing Belt Base 71A Laminate 71b Nickel Layer 71c Copper Layer 71d Protective Layer 72 Elastic Layer 73 Release Layer 74 Sliding Layer

JP 2014-194522 A

Claims (6)

A base material for a fixing belt having a laminate formed by laminating a plurality of metal layers and having flexibility,
The laminate is
A nickel layer composed of nickel;
A copper layer comprising an alloy of copper and tin laminated to the nickel layer;
A fixing belt base material comprising: a protective layer made of nickel and laminated on a surface of the copper layer opposite to the surface on which the nickel layer is laminated.   2. The fixing belt substrate according to claim 1, wherein the laminate has a thickness of 20 μm or more and 50 μm or less, and the thickness of the copper layer is larger than the thickness of the nickel layer.   The base material for a fixing belt according to claim 1 or 2, wherein the copper layer has a tensile elastic modulus of 40 GPa or more. A fixing belt comprising the fixing belt substrate according to any one of claims 1 to 3,
The fixing belt substrate is formed in an endless shape having the protective layer as an outer periphery and the nickel layer as an inner periphery,
An elastic layer formed on the outer peripheral surface of the fixing belt substrate;
A release layer formed on the outer peripheral surface of the elastic layer;
A sliding layer formed on the inner peripheral surface of the fixing belt substrate;
A fixing belt characterized by comprising:   A fixing device comprising the fixing belt according to claim 4.   An image forming apparatus comprising the fixing device according to claim 5.

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