JP2017090537A - Fixing device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixing device that is excellent in wear resistance on an inner peripheral surface of a fixing belt.SOLUTION: There is provided a fixing device 100 comprising: a fixing belt 102 that has at least an inner peripheral surface formed of a resin material containing a polyimide resin; a pressure member 104 that applies pressure to an outer peripheral surface of the fixing belt 102 and sandwiches a recording medium P on which an unfixed toner image T is formed with the fixing belt 102; a slide member that slides while in contact with the inner peripheral surface of the fixing belt 102; and a lubricant that is applied on the inner peripheral surface of the fixing belt 102, contains at least a lubricant oil with an amine equivalent amount of 50,000 g/mol or less as a main component, and has a kinetic viscosity at 25°C of 2.0×10m/s or less.SELECTED DRAWING: Figure 2

Description

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

  2. Description of the Related Art In recent years, a fixing for an image forming apparatus in which a recording medium on which an unfixed toner image is formed is sandwiched between a fixing belt and a pressure member that contacts the fixing belt, and the toner image is fixed to the recording medium by heating and pressing. A device has been proposed.

  For example, Patent Document 1 discloses a pressure fixing device that applies pressure to a recording medium by passing a recording medium holding an unfixed toner image through a nip region and pressurizes and fixes the unfixed toner image to the recording medium. A rotation drive that feeds the recording medium to the nip region by rotating the roll, and a roll that feeds the recording medium from the nip region, and the nip region is formed by pressing the surface against the roll to form the nip region. An annular belt that circulates according to the movement of the recording medium passing therethrough, and a pressing member that is disposed on the back side of the annular belt and presses the surface of the annular belt against the roll in contact with the back surface. , A lubricant is applied to the surface in contact with the pressing member, and the formula b ≦ a (where b is the annular bell of the lubricant) It represents contact angle to the back surface, a is the lubricant, the pressing represents the contact angle with respect to members), thereby satisfying a pressure fixing device is disclosed.

JP 2005-078025 A

  The fixing belt, a pressure member that pressurizes the outer peripheral surface of the fixing belt and sandwiches a recording medium having an unfixed toner image formed on the surface, and the inner peripheral surface of the fixing belt slide in contact with the fixing belt. In a fixing device for an image forming apparatus including a sliding member, a lubricant is applied to the inner peripheral surface of the fixing belt from the viewpoint of suppressing wear due to friction with the sliding member. However, the image forming apparatus is required to have a longer life, and the fixing belt is also required to further improve the wear resistance against sliding with the sliding member.

The present invention provides a fixing belt, a pressure member, a sliding member that slides in contact with the inner peripheral surface of the fixing belt, and an inner peripheral surface of the fixing belt, the inner peripheral surface of which is made of a resin material containing polyimide resin. And the lubricant having a kinematic viscosity at 25 ° C. of 2.0 × when the amine equivalent of the lubricating oil contained as a main component in the lubricant exceeds 50,000 g / mol. It is an object of the present invention to provide a fixing device that is superior in wear resistance on the inner peripheral surface of the fixing belt as compared with a case where at least one of the cases exceeding 10 ⁻⁴ m ² / s is satisfied.

In order to achieve the above object, the following invention is provided.
The invention according to claim 1 is a tubular substrate,
A fixing belt having at least an inner peripheral surface made of a resin material containing polyimide resin;
A pressure member that pressurizes an outer peripheral surface of the fixing belt and sandwiches a recording medium having an unfixed toner image formed on the surface together with the fixing belt;
A sliding member that slides in contact with the inner peripheral surface of the fixing belt;
A lubricant applied to the inner peripheral surface of the fixing belt, comprising at least a lubricating oil having an amine equivalent of 50,000 g / mol or less as a main component, and a kinematic viscosity at 25 ° C. of 2.0 × 10 ^−4. a lubricant that is less than or equal to m ² / s;
A fixing device.

The invention according to claim 2
An image carrier,
Charging means for charging the surface of the image carrier;
An electrostatic latent image forming means for forming an electrostatic latent image on the surface of the charged image carrier;
Developing means for developing the electrostatic latent image formed on the surface of the image carrier with a developer containing toner to form a toner image;
Transfer means for transferring the toner image to the surface of the recording medium;
The fixing device according to claim 1, wherein the toner image is fixed on the recording medium.
An image forming apparatus comprising:

According to the first aspect of the present invention, the fixing belt, the pressure member, the sliding member that slides in contact with the inner peripheral surface of the fixing belt, and the inner peripheral surface made of a resin material containing polyimide resin, In the embodiment having the lubricant applied to the inner peripheral surface of the fixing belt, when the amine equivalent of the lubricating oil contained as a main component in the lubricant exceeds 50,000 g / mol, and the movement of the lubricant at 25 ° C. As compared with the case where at least one of the viscosities exceeding 2.0 × 10 ⁻⁴ m ² / s is satisfied, a fixing device having excellent wear resistance on the inner peripheral surface of the fixing belt is provided.

According to the second aspect of the present invention, the fixing belt, the pressure member, the sliding member that contacts and slides on the inner peripheral surface of the fixing belt, and the inner peripheral surface made of a resin material containing polyimide resin, In an aspect including a fixing device having a lubricant applied to the inner peripheral surface of the fixing belt, the amine equivalent of the lubricating oil contained as a main component in the lubricant exceeds 50,000 g / mol, and As compared with the case where at least one of the cases where the kinematic viscosity at 25 ° C. exceeds 2.0 × 10 ⁻⁴ m ² / s is satisfied, an image forming apparatus having excellent fixing performance even after repeated image formation is provided.

2 is a schematic cross-sectional view illustrating an example of a layer configuration of a fixing belt in the present embodiment. 1 is a schematic configuration diagram illustrating an example of a fixing device according to an exemplary embodiment. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an exemplary embodiment.

  Embodiments of the present invention will be described below with reference to the drawings.

<Fixing device>
The fixing device according to the present embodiment includes a fixing belt, a pressure member that pressurizes the outer peripheral surface of the fixing belt, and sandwiches a recording medium having an unfixed toner image formed on the surface together with the fixing belt, and the fixing belt A sliding member that slides in contact with the inner peripheral surface of the fixing belt and a lubricant applied to the inner peripheral surface of the fixing belt.
The fixing belt is made of a resin material (hereinafter also simply referred to as “PI resin material”) including at least an inner peripheral surface thereof. Further, the lubricant contains at least a lubricating oil having an amine equivalent of 50,000 g / mol or less (hereinafter also simply referred to as “amine lubricating oil”) as a main component, and has a kinematic viscosity at 25 ° C. of 2.0 × 10 ^{− 4} m ² / s or less.

  The “main component” means that the proportion of the lubricant in the lubricant is 50% by mass or more. In the present embodiment, the proportion of the amine lubricating oil in the lubricant applied to the inner peripheral surface of the fixing belt is 50% by mass or more, preferably 80% by mass or more, and preferably 100% by mass. It is particularly preferred.

Conventionally, a fixing belt has been used in a fixing device in an image forming apparatus. In this fixing device, the fixing belt and the pressure member come into contact to form a nip region, and the toner image is fixed by passing a recording medium having an unfixed toner image formed on the surface through the nip region. The A sliding member that slides on the fixing belt is provided on the inner peripheral surface of the rotationally driven fixing belt. As the sliding member, for example, a pressing member for pressing the fixing belt toward the pressing member side, or a member for generating a magnetic field used in an electromagnetic induction heating type fixing device is brought into contact with the inner peripheral surface of the fixing belt. A temperature-sensitive magnetic material disposed in the same manner. In order to suppress wear due to friction with these sliding members, a lubricant may be applied to the inner peripheral surface of the fixing belt.
However, the image forming apparatus is required to have a longer life, and the fixing belt is also required to further improve the wear resistance against sliding with the sliding member.

On the other hand, in this embodiment, at least the inner peripheral surface of the fixing belt is made of a resin material (PI resin material) containing a polyimide resin, and the lubricant is a lubricating oil (amine lubrication) having an amine equivalent of 50,000 g / mol or less. Oil) at least as a main component, and the kinematic viscosity at 25 ° C. of the lubricant is 2.0 × 10 ⁻⁴ m ² / s or less, thereby improving the wear resistance on the inner peripheral surface of the fixing belt. obtain.

The reason for this effect is not necessarily clear, but is presumed as follows.
If the kinematic viscosity of the lubricant is in the above range, the viscosity is further reduced, the lubricant is likely to spread over the entire inner peripheral surface of the fixing belt, and the occurrence of uneven wear due to the uneven distribution of the lubricant is considered to be suppressed. .

  Further, a gap may exist in part between the inner peripheral surface of the fixing belt and the sliding member in contact with the inner peripheral surface. For example, in the sliding member such as the pressing member or the temperature-sensitive magnetic body, there may be a portion that does not contact the inner peripheral surface of the fixing belt from the viewpoint of molding accuracy, that is, there is an unintended gap. There is. When such a gap exists, the lubricant is buried in the gap and stays there, so that the effect of suppressing wear on the fixing belt may be reduced. On the other hand, in this embodiment, the kinematic viscosity of the lubricant is in the above range, and the viscosity is further reduced, so that the retention of the lubricant in the gap is reduced, and wear suppression by the lubricant is more exhibited. it is conceivable that.

  However, when the viscosity of the lubricant is lowered, the fluidity increases and it becomes difficult to stay on the inner peripheral surface of the fixing belt, so that the lubricant may be detached from the inner peripheral surface of the fixing belt. The effect may be reduced. On the other hand, in this embodiment, at least the inner peripheral surface of the fixing belt is made of a resin material containing a polyimide resin, and the lubricant contains a lubricating oil having an amine equivalent of 50,000 g / mol or less as a main component. The lubricant is easily held on the inner peripheral surface of the fixing belt by the interaction between the amino group in the lubricating oil and the polyimide in the fixing belt. For this reason, it is considered that the detachment of the lubricant from the inner peripheral surface of the fixing belt is suppressed, and the wear suppression by the lubricant is further exhibited.

  Next, the configuration of the fixing device according to the present embodiment will be described in more detail.

-Lubricant The lubricant has a kinematic viscosity at 25 ° C. of 2.0 × 10 ⁻⁴ m ² / s ( ²⁰⁰ cSt) or less. Furthermore, the kinematic viscosity is preferably 1.5 × 10 ⁻⁴ m ² / s (150 cSt) or less, more preferably 1 × 10 ⁻⁴ m ² / s (100 cSt) or less, Is preferably as low as possible.

When the kinematic viscosity at 25 ° C. of the lubricant exceeds 2.0 × 10 ⁻⁴ m ² / s ( ²⁰⁰ cSt), uneven wear occurs due to uneven distribution of the lubricant on the inner peripheral surface of the fixing belt. Further, when there is a gap between a part of the inner peripheral surface of the fixing belt and the sliding member, the lubricant stays in the gap and wear of the fixing belt is not suppressed well.

  The kinematic viscosity of the lubricant can be adjusted by a conventionally known method such as adjustment of the molecular weight of the lubricating oil used in the lubricant.

The kinematic viscosity of the lubricant is obtained from the following equation by measuring the capillary outflow time of the liquid (lubricant) in accordance with JIS Z 8803 (2011) and the time and the viscometer constant.
Kinematic viscosity (cSt) = Viscometer constant x Outflow time (seconds)

  The lubricant contains a lubricating oil (amine lubricating oil) having an amine equivalent of 50,000 g / mol or less as its main component (50% by mass or more). In addition, the content ratio in the lubricant of the specific amine lubricating oil is preferably as large as possible, and particularly preferably 100% by mass.

When the amine equivalent of the amine lubricating oil exceeds 50,000 g / mol, the lubricant is detached from the inner peripheral surface of the fixing belt, and as a result, the wear of the fixing belt is not suppressed well.
Furthermore, the amine equivalent of the amine lubricating oil is preferably 40,000 g / mol or less, more preferably 35,000 g / mol or less.
The lower limit of the amine equivalent of the amine lubricating oil is not particularly limited, but is preferably 3,500 g / mol or more from the viewpoint of ease of production of the lubricating oil.

The amine equivalent is a value obtained by dividing the total molecular weight of the amine lubricating oil by the number of amino groups. To measure the amine equivalent, weigh the amine lubricating oil, add a 1: 1 mixture of isopropyl alcohol and toluene, stir and dissolve, then titrate with 0.1N hydrochloric acid solution using an automatic titrator, and use the following formula: This is done by calculating the amine equivalent.
Amine equivalent (g / mol) = oil amount (g) × 1,000 / {hydrochloric acid consumption (ml) × 0.1}

  As a lubricating oil (amine lubricating oil) having an amine equivalent in the above range, for example, an amino-modified silicone oil is preferably used. An amino-modified silicone oil is an oil having an amino group in the side chain.

  Specific examples of the amino-modified silicone oil include amino-modified silicone oils represented by the following general formula (1).

In the general formula (1), A represents —R—X, and b and c represent 0 <b ≦ 10 and 10 ≦ c ≦ 1000, respectively. R represents an alkylene group having 1 to 8 carbon atoms, and X represents —NH ₂ or —NH (CH ₂ ) ₂ NH ₂ .

  In order to adjust the amine equivalent to be in the above range, a conventionally known method such as a method of changing the number of repeating amine-modified repeating structures in the molecule of the amine lubricating oil can be used.

  The lubricant may contain other lubricating oil in addition to the specific amine lubricating oil which is the main component. Examples of other lubricating oils include amine-modified silicone oils whose amine equivalents are outside the above range, and silicone oils that are not amine-modified. For example, dimethyl silicone oil, organometallic salt added dimethyl silicone oil, hindered amine added dimethyl silicone oil, organometallic salt and hindered amine added dimethyl silicone oil, methylphenyl silicone oil, organometallic salt added amino modified silicone oil, hindered amine added amino modified silicone oil Carboxy-modified silicone oil, silanol-modified silicone oil, sulfonic acid-modified silicone oil and the like are used. Further, fluorine oil (perfluoropolyether oil, modified perfluoropolyether oil), synthetic lubricating oil grease (for example, silicone grease, fluorine grease) in which a solid substance and a liquid are mixed may be used. In addition, you may add additives, such as antioxidant, in silicone oil.

Fixing belt The fixing belt is made of a resin material (PI resin material) including at least an inner peripheral surface thereof.
The configuration of the fixing belt is not particularly limited as long as the inner peripheral surface is made of the PI resin material. Even if the fixing belt is made of a single layer belt made of the PI resin material, the PI belt may be used. A laminated type structure in which another layer is laminated on a base material made of a resin material may be used.

  Examples of the polyimide resin include imidized polyamic acid (polyimide resin precursor) which is a polymer of tetracarboxylic dianhydride and a diamine compound. Specifically, as a polyimide resin, for example, an equimolar amount of tetracarboxylic dianhydride and a diamine compound was polymerized in a solvent to obtain a polyamic acid solution, and obtained by imidizing the polyamic acid. Is. In addition, a polyimide resin may be used individually by 1 type, and may be used together 2 or more types.

  Specific examples of tetracarboxylic dianhydride include pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyl, and the like. Tetracarboxylic dianhydride, 2,3,3 ′, 4-biphenyltetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetra Carboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,2'-bis (3,4-dicarboxyphenyl) sulfonic dianhydride, perylene-3,4,9 , 10-tetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, ethylenetetracarboxylic dianhydride and the like.

On the other hand, specific examples of the diamine compound include, for example, 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylmethane, 3,3′-diaminodiphenylmethane, 3,3′-dichlorobenzidine, 4,4′-diamino. Diphenyl sulfide, 3,3′-diaminodiphenyl sulfone, 1,5-diaminonaphthalene, m-phenylenediamine, p-phenylenediamine, 3,3′-dimethyl4,4′-biphenyldiamine, benzidine, 3,3′- Dimethylbenzidine, 3,3′-dimethoxybenzidine, 4,4′-diaminodiphenylsulfone, 4,4′-diaminodiphenylpropane, 2,4-bis (β-aminotert-butyl) toluene, bis (p-β- Amino-tert-butylphenyl) ether, bis (p-β-methyl-δ-aminophenyl) base Zen, bis-p- (1,1-dimethyl-5-amino-pentyl) benzene, 1-isopropyl-2,4-m-phenylenediamine, m-xylylenediamine, p-xylylenediamine, di (p- Aminocyclohexyl) methane, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, diaminopropyltetramethylene, 3-methylheptamethylenediamine, 4,4-dimethylheptamethylenediamine, 2,11- Diaminododecane, 1,2-bis-3-aminopropoxyethane, 2,2-dimethylpropylenediamine, 3-methoxyhexamethylenediamine, 2,5-dimethylheptamethylenediamine, 3-methylheptamethylenediamine, 5-methyl Nonamethylenedi Amine, 2,17-diaminoeicosadecane, 1,4-diaminocyclohexane, 1,10-diamino-1,10-dimethyldecane, 12-diaminooctadecane, 2,2-bis [4- (4-aminophenoxy) Phenyl] propane, piperazine, H ₂ N (CH ₂ ) ₃ O (CH ₂ ) ₂ O (CH ₂ ) NH ₂ , H ₂ N (CH ₂ ) ₃ S (CH ₂ ) ₃ NH ₂ , H ₂ N (CH ₂ ) ₃ N (CH ₃ ) ₂ (CH ₂ ) ₃ NH _{2 and the} like.

The PI resin material constituting at least the inner peripheral surface of the fixing belt may contain a resin other than the polyimide resin. However, the proportion of the polyimide resin in the total resin contained in the PI resin material is preferably 50% by mass or more. Furthermore, the above percentage is preferably 70% by mass or more, more preferably 90% by mass or more, and particularly preferably 100% by mass.
As the resin other than the polyimide resin contained in the PI resin material, what is generally called engineering plastic is suitable, for example, fluorine resin, polyamideimide (PAI), polybenzimidazole (PBI), polyetheretherketone (PEEK). ), Polysulfone (PSU), polyethersulfone (PES), polyphenylene sulfide (PPS), polyetherimide (PEI), wholly aromatic polyester (liquid crystal polymer), and the like.

  The configuration of the fixing belt may be a single layer belt made of a PI resin material or a laminated type structure in which other layers are laminated on a base material made of a PI resin material. Good. Further, the fixing belt may be an IH (induction heating) fixing belt that generates heat by electromagnetic induction, that is, a laminated belt configuration including a metal layer that generates heat by electromagnetic induction.

  Next, a configuration of an IH fixing belt that generates heat by electromagnetic induction will be described as an example of the fixing belt in the present embodiment.

FIG. 1 is a schematic configuration diagram illustrating an IH fixing belt as an example of a fixing belt used in the present embodiment.
A fixing belt 10 shown in FIG. 1 is an endless belt having a layer configuration in which a metal heating layer, an elastic layer 10E, and a release layer 10F are sequentially laminated on an outer peripheral surface of a tubular base material 10A. The metal heating layer is formed by laminating a base metal layer 10B, an electromagnetic induction metal layer 10C that self-heats due to electromagnetic induction, and a metal protective layer 10D in this order.
The base material 10A is made of a resin material (PI resin material) containing a polyimide resin.

[Substrate 10A]
The base material 10A is made of a resin material (PI resin material) containing a polyimide resin.
A heat insulating effect may be further improved by adding a filler having a heat insulating effect to the PI resin material or by foaming the resin.

  The thickness of the base material 10A is preferably in the range of 10 μm or more and 200 μm or less, more preferably in the range of 30 μm or more and 100 μm or less, from the viewpoint of achieving both rigidity and flexibility for realizing long-term repetitive circumferential conveyance of the fixing belt. desirable.

Further, the tensile strength of the base material 10A preferably satisfies 200 MPa or more (more preferably 250 MPa or more). The tensile strength of a base material can be adjusted with the kind of resin, the kind of filler, and addition amount.
In addition, the tensile strength (MPa) of the base material is obtained by cutting the base material into a strip shape having a width of 5 mm and installing the base material in a tensile tester Model 1605N (manufactured by Aiko Engineering Co., Ltd.) and pulling at a constant speed of 10 mm / sec. Measured with tensile strength at break (MPa).

[Base metal layer 10B]
The base metal layer 10B is a layer formed in advance in order to form the electromagnetic induction metal layer 10C on the outer peripheral surface of the base material 10A by an electrolytic plating method, and is provided as necessary. As a method of forming the electromagnetic induction metal layer 10C, an electrolytic plating method is desirable from the viewpoint of cost and the like, but when the base material 10A made of a PI resin material is used, it is difficult to perform direct electrolytic plating. Therefore, it is preferable to provide the base metal layer 10B for forming the electromagnetic induction metal layer 10C.

  Examples of the method for forming the base metal layer 10B on the outer peripheral surface of the substrate 10A include an electroless plating method, a sputtering method, a vapor deposition method, and the like, and a chemical plating method (electroless plating method) from the viewpoint of easiness of film formation. Of these, general electroless nickel plating layers, electroless copper plating layers, and the like are preferable.

  In addition, before the base metal layer 10B is formed on the outer peripheral surface of the base material 10A by the electroless plating method, the surface roughness of the outer peripheral surface of the base material 10A is roughened in advance so that the metal particles are easily attached (roughness). Surface treatment) may be performed. Examples of the roughening treatment include a method of roughening the surface of the substrate 10A by sandblasting using alumina abrasive grains or the like, cutting, sandpaper polishing, or the like.

  The thickness of the base metal layer 10B is desirably in the range of 0.1 μm to 5 μm, and more desirably in the range of 0.3 μm to 3 μm.

  The thickness of each layer constituting the fixing belt in the present embodiment is determined by accelerating voltage of a scanning electron microscope (“JSM6700F” manufactured by JEOL Ltd.) by preparing a cross section in the circumferential direction and axial direction of the fixing belt cylindrical body. It is the value which measured the film thickness from the observation image in 2.0 kV and 5000 times.

[Electromagnetic induction metal layer 10C]
The electromagnetic induction metal layer 10C is a heat generation layer having a function of generating heat by an eddy current generated in this layer when a magnetic field is applied, and is made of a metal that generates an electromagnetic induction effect.
As a metal that generates electromagnetic induction, for example, a single metal such as nickel, iron, copper, gold, silver, aluminum, chromium, tin, zinc, or an alloy containing two or more kinds of metals may be selected. . In consideration of cost, heat generation performance, and workability, copper, nickel, aluminum, iron, and chromium are suitable, and among these, copper or an alloy containing copper as a main component is particularly desirable.

  The electromagnetic induction metal layer 10C is formed by performing a known method, for example, electrolytic plating.

  The optimum thickness of the electromagnetic induction metal layer 10C differs depending on the metal material. For example, when copper is used for the electromagnetic induction metal layer 10C, the thickness of the electromagnetic induction metal layer 10C is used from the viewpoint of efficiently generating heat. Is preferably in the range of 3 μm to 50 μm, more preferably in the range of 3 μm to 30 μm, and still more preferably in the range of 5 μm to 20 μm.

[Metal protective layer 10D]
A metal protective layer is provided on the outer peripheral surface side of the electromagnetic induction metal layer 10C in order to improve the film strength, suppress cracks due to repeated deformation, oxidative deterioration due to repeated heating for a long time, etc., and maintain heat generation characteristics. It is preferably provided in contact with the electromagnetic induction metal layer 10C.

  The metal protective layer 10D is a thin film with high breaking strength, high durability and high oxidation resistance, and is preferably an oxidation resistant metal. Specifically, for example, it may be configured to contain copper or nickel, and is particularly an oxidation-resistant metal from the viewpoint of suppressing the occurrence of cracks due to repeated deformation and oxidative deterioration due to repeated heating. It is desirable to include nickel (or a nickel alloy).

  The optimum thickness of the metal protective layer varies depending on the material. For example, when the metal protective layer is formed of nickel, flexibility is obtained while suppressing the occurrence of cracks due to insufficient breaking strength. From the viewpoint of suppressing the warm-up time to be short without increasing the heat capacity of itself, it is preferably in the range of 2 μm to 20 μm, more preferably in the range of 2 μm to 15 μm, and in the range of 5 μm to 10 μm. More preferably it is.

The metal protective layer is preferably formed by an electrolytic plating method in consideration of workability with a thin film, and among them, electrolytic nickel plating having high strength is more preferable.
In the case of forming by electroplating, first, a plating solution containing metal ions such as nickel ions is prepared, and the substrate 10A having the base metal layer 10B and the electromagnetic induction metal layer 10C is immersed in this plating solution to perform electrolytic plating. Then, an electrolytic plating layer having a required thickness is formed.

[Adhesive layer]
An adhesive layer may be interposed between the layer constituting the outermost surface of the metal heating layer (the metal protective layer 10D in FIG. 1) and the elastic layer 10E from the viewpoint of improving the adhesion between the two layers. .

  As the adhesive used for the adhesive layer, an adhesive having little change in physical properties even in the state where the adjacent metal heating layer generates heat and excellent in heat transfer to the outer peripheral surface side is preferable. Specific examples include silane coupling agent-based adhesives, silicone-based adhesives, epoxy resin-based adhesives, and urethane resin-based adhesives.

  The thickness of the adhesive layer is preferably 0.1 μm or more and 1 μm or less, and more preferably 0.2 μm or more and 0.5 μm or less.

[Elastic layer 10E]
The elastic layer 10E is a layer that plays the role of closely contacting the surface of the fixing belt to the toner image following the unevenness of the toner image on the recording medium. In particular, when a multicolor image is formed, the elastic layer 10E can obtain an image in which the color development deterioration and the gloss unevenness due to the heating unevenness of the recording medium and the toner image are suppressed. Further, since the elastic layer 10E is deformed in the contact region with the pressure member and a contact width can be obtained even with a low load, heat is transferred to the toner image even if the process speed (recording medium conveyance speed) is increased. Even when fixing is performed and a black-and-white image is formed, high speed is realized.

The elastic layer 10E is preferably made of an elastic material that can be restored to its original shape even when deformed by applying an external force of 100 Pa, for example.
In the elastic layer 10E in the present embodiment, silicone rubber is preferably used as an elastic material. Examples of the silicone rubber include RTV silicone rubber, HTV silicone rubber, and liquid silicone rubber. Specifically, polydimethyl silicone rubber (MQ), methyl vinyl silicone rubber (VMQ), methyl phenyl silicone rubber (PMQ). ), Fluorosilicone rubber (FVMQ) and the like.
Examples of the commercially available product include liquid silicone rubber SE6744 manufactured by Toray Dow Corning Silicone.

  In the present embodiment, in the elastic material included in the elastic layer 10E, it is preferable that silicone rubber is a main component (that is, 50% or more in terms of mass ratio), and the content is 90% by mass or more. It is more preferable that the content is 99% by mass or less.

The elastic layer 10E may use another material as an elastic material. For example, heat-resistant rubber such as fluorine rubber can be used. Examples of the fluororubber include vinylidene fluoride rubber, tetrafluoroethylene / propylene rubber, tetrafluoroethylene / perfluoromethyl vinyl ether rubber, phosphazene rubber, and fluoropolyether.
Examples of commercially available products include Viton B-202 manufactured by DuPont Dow elastmers.

Various additives may be blended in the elastic layer.
In particular, it is preferable to add a filler from the viewpoint of improving the thermal conductivity of the elastic layer 10E. In addition, the thermal conductivity of the filler is preferably 0.3 W / mK or more, more preferably 50 W / mK or more, and further preferably 100 W / mK or more from the viewpoint of obtaining higher thermal conductivity in the elastic layer 10E.

Filler materials include carbide (eg, carbon black, carbon fiber, carbon nanotube, etc.), titanium oxide, silicon carbide, talc, mica, kaolin, iron oxide, calcium carbonate, calcium silicate, magnesium oxide, graphite, silicon nitride And well-known inorganic fillers such as boron nitride, iron oxide, cerium oxide, aluminum oxide, magnesium carbonate, and metal silicon.
Among these, silicon nitride, silicon carbide, graphite, boron nitride, and carbide are preferable from the viewpoint of thermal conductivity.

  The filler content of the elastic layer 10E may be determined by the required thermal conductivity, mechanical strength, and the like. For example, the filler content in the elastic layer 10E is preferably in the range of 1% by mass to 20% by mass, more preferably in the range of 3% by mass to 15% by mass, and more preferably in the range of 5% by mass to 10% by mass. A range is further preferred.

  Examples of additives include softeners (paraffins, etc.), processing aids (stearic acid, etc.), anti-aging agents (amines, etc.), and vulcanizing agents (sulfur, metal oxides, peroxides, etc.). And functional fillers (such as alumina).

  The thickness of the elastic layer 10E is, for example, preferably 30 μm or more and 600 μm or less, and preferably 100 μm or more and 500 μm or less.

[Release layer 10F]
The release layer 10 </ b> F is a layer that plays a role of preventing the toner image in a molten state from adhering to the surface (outer peripheral surface) on the side in contact with the recording medium. The release layer 10F is provided as necessary.

  The release layer 10F is preferably configured to include a low surface energy material such as a fluorine-based compound as a main component. Examples of the fluorine compound include fluororubber, polytetrafluoroethylene (hereinafter referred to as “PTFE”), perfluoroalkyl vinyl ether copolymer (hereinafter referred to as “PFA”), ethylene tetrafluoride ethylene hexafluoride propylene copolymer. A fluororesin such as a polymer (hereinafter referred to as “FEP”) is exemplified, but it is not particularly limited.

  The thickness of the release layer 10F is preferably in the range of 10 μm to 100 μm, and more preferably in the range of 20 μm to 50 μm. When the thickness of the release layer 10F is 10 μm or more, wear of the release layer 10F due to repeated friction at the edge of a recording medium such as paper is suppressed. Further, when the thickness of the release layer 10F is 100 μm or less, the surface flexibility is maintained, the granularity of the fixed image is maintained, and the warm-up time is shortened.

A known method may be applied to form the elastic layer 10E and the release layer 10F. For example, the elastic layer 10E and the release layer 10F may be sequentially formed on the metal heating layer by a coating method.
When the elastic layer 10E and the release layer 10F are formed on the metal heat generating layer by a coating method, before applying these layers, an appropriate layer is applied to the surface of the metal heat generating layer or the elastic layer 10E as necessary. It is desirable to perform pretreatment with a primer material. By performing this pretreatment, the adhesion between the layers is further improved.

  In addition, when the elastic layer 10E and the release layer 10F are laminated on the metal heat generating layer by a coating method, the elastic layer 10E and the release layer 10F are formed through a step of heat-treating the coated film. Is done. The heat treatment of the coating film may be performed in an inert gas (nitrogen gas, argon gas, etc.) atmosphere.

  The release layer 10F is prepared by preparing a tube-like release layer in advance, for example, by forming an adhesive layer on the inner surface of the tube and then covering the outer periphery of the elastic layer 10E. May be.

  Next, another configuration of the fixing device according to the present embodiment will be described.

The fixing device according to the present embodiment has various configurations, and pressurizes the fixing belt and the outer peripheral surface of the fixing belt, and pressurizes the recording medium on which the unfixed toner image is formed with the fixing belt. There is no particular limitation as long as it has a member, a sliding member that slides in contact with the inner peripheral surface of the fixing belt, and a lubricant applied to the inner peripheral surface of the fixing belt.
For example, the pressure member includes a pressure roll and a pressure belt.
Further, a heating and fixing method in which at least one of the fixing belt and the pressure member is heated to press and heat an unfixed toner image may be used. As a heating method, a known method such as a heating method using a heater or an electromagnetic induction heating method using an IH (induction heating) fixing belt that generates heat by electromagnetic induction may be employed.

  Here, as an example of the fixing device according to the present exemplary embodiment, a configuration of an electromagnetic induction heating type fixing device will be described.

  FIG. 2 is a schematic configuration diagram illustrating an electromagnetic induction heating type fixing device as an example of the fixing device according to the present exemplary embodiment.

  As shown in FIG. 2, the fixing device 100 includes a housing 101 in which an opening for entering or discharging recording paper (recording medium) P is formed. An endless fixing belt 102 that rotates in the direction of arrow D is provided inside the housing 101.

  An annular cap member (not shown) is attached to both ends of the fixing belt 102 in the axial direction (the depth direction in FIG. 2 and hereinafter referred to as the Z direction). The fixing belt 102 is rotatable by a cap member rotatably supported by a bearing (not shown) provided in the housing 101.

  The fixing belt 102 is connected to a drive source (not shown) including a motor, and a pressure roll (pressure member) 104 described later is separated from the fixing belt 102 by a retract mechanism (not shown) ( At the time of retraction), it is rotated by the drive source. When the fixing belt 102 reaches a preset temperature, the pressure roll 104 moves and comes into contact with the fixing belt 102.

  A bobbin 108 made of an insulating material is disposed at a position facing the outer peripheral surface of the fixing belt 102. The bobbin 108 is formed in an arc shape that follows the outer peripheral surface of the fixing belt 102, and a convex portion 108 </ b> A is provided at the center in the circumferential direction of the bobbin 108 on the side opposite to the fixing belt 102 side. An excitation coil 110 as an example of a magnetic field generation unit is wound around the bobbin 108 a plurality of times in the axial direction (Z direction) around the convex portion 108A.

  Further, on the opposite side of the bobbin 108 with the exciting coil 110 in between, a magnetic core 112 made of a ferrite-based magnetic body formed in an arc shape following the arc shape of the bobbin 108 is arranged on the bobbin 108. It is supported.

  On the other hand, the fixing belt 102 and the recording paper P are pressed toward a support 122 described later and the rotation of the fixing belt 102 at a position facing the outer peripheral surface of the fixing belt 102 and on the side opposite to the exciting coil 110 side. Accordingly, a pressure roll (pressure member) 104 that is driven to rotate in the direction of arrow E is provided. By the rotation of the pressure roll 104 and the fixing belt 102, the recording paper P enters and is discharged in the direction of arrow C.

  For example, the pressure roll 104 has a structure in which a silicone rubber and PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) are coated around a cored bar 106 made of aluminum. The pressure roll 104 can be moved in the direction of arrow A (direction approaching the fixing belt 102) or the direction of arrow B (direction away from the fixing belt 102) by a retract mechanism (not shown). To the outer peripheral surface of the fixing belt 102 and pressurize, or move in the direction of the arrow B to move away from the outer peripheral surface of the fixing belt 102.

  Next, the inner configuration of the fixing belt 102 will be described.

  As shown in FIG. 2, on the inner side of the fixing belt 102, a temperature-sensitive magnetic member 150, which will be described in detail later, a support body 122 that supports the temperature-sensitive magnetic member 150, and a pressing member that presses the fixing belt 102 against the pressure roll 104. A member 124, a thermistor 130 that detects the temperature of the fixing belt 102, and a thermostat 137 that suppresses excessive temperature rise of the fixing belt 102 are provided as main parts. The temperature-sensitive magnetic member 150 is biased toward the fixing belt 102 side. In the fixing device 100 shown in FIG. 2, the temperature-sensitive magnetic member 150 and the pressing member 124 correspond to sliding members that slide in contact with the inner peripheral surface of the fixing belt 102.

  The support body 122 is formed by combining a plurality of steel plate materials whose longitudinal direction is the Z direction, and both ends in the Z direction pass through a cap member (not shown) and are fixed to the housing 101. . The support body 122 supports the temperature-sensitive magnetic member 150 and the pressing member 124 and counters the pressure applied from the pressure roll 104.

  The pressing member 124 has one end surface in the X direction fixed to the support body 122 and the other end surface in contact with the inner peripheral surface of the fixing belt 102 on the pressure roll 104 side. It is composed of a urethane rubber pad that can be deformed flexibly. The pressing member 124 sandwiches the fixing belt 102 between the pressure roll 104 and forms a nip portion N where the fixing belt 102 and the pressure roll 104 come in contact with each other in the circumferential direction.

  On the other hand, the thermistor 130 and the thermostat 137 are attached to the support body 122 with screws.

  Next, details of the temperature-sensitive magnetic member 150 will be described.

  The temperature-sensitive magnetic member 150 has a characteristic in which the magnetic permeability starts to decrease continuously when the magnetic permeability change temperature is equal to or higher than the heat setting temperature of the fixing belt 102 and equal to or lower than the heat resistance temperature of the fixing belt 102. Consists of temperature-sensitive magnetic material. Specifically, a magnetic shunt steel, an amorphous alloy or the like is used, and a metal alloy material made of Fe, Ni, Si, B, Nb, Cu, Zr, Co, Cr, V, Mn, Mo, etc. Fe-Ni binary magnetic shunt steel and Fe-Ni-Cr ternary magnetic shunt steel are preferably used. In this embodiment, an Fe—Ni alloy is used as an example.

  The permeability change start temperature is a temperature at which the permeability (measured in accordance with JIS C2531) starts to decrease continuously, and refers to the point at which the penetration amount of the magnetic flux of the magnetic field starts to change. Further, the magnetic permeability change start temperature is different from the Curie point.

  As an example, the temperature-sensitive magnetic member 150 is disposed inside the fixing belt 102 along the exciting coil 110 (in a range facing the exciting coil 110) in contact with the entirety. The outer peripheral surface of the temperature-sensitive magnetic member 150 is subjected to surface treatment (for example, nitriding treatment) for ensuring the slidability of the fixing belt 102. Note that the temperature-sensitive magnetic member 150 is almost entirely in contact with the inside of the fixing belt 102 in the Z direction.

<Image forming apparatus>
An image forming apparatus according to the present embodiment includes an image carrier, a charging device that charges the surface of the image carrier, and an electrostatic latent image forming device that forms an electrostatic latent image on the charged surface of the image carrier. A developing device that develops the electrostatic latent image formed on the surface of the image carrier with toner to form a toner image, and a transfer that transfers the toner image formed on the surface of the image carrier to a recording medium And a fixing device according to this embodiment for fixing the toner image to the recording medium.

FIG. 3 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present embodiment.
As shown in FIG. 3, the image forming apparatus 200 according to the present embodiment includes a photosensitive member (an example of an image holding member) 202, a charging device 204, a laser exposure device (an example of an electrostatic latent image forming unit) 206, and a mirror 208. , A developing device (an example of a developing unit) 210, an intermediate transfer member 212, a transfer roll (an example of a transferring unit) 214, a cleaning device 216, a static eliminating device 218, a fixing device 100, and a paper feeding device (a paper feeding unit 220, paper feeding). A roller 222, a registration roller 224, and a recording medium guide 226).

  When image formation is performed with the image forming apparatus 200, first, a non-contact type charging device 204 provided in the vicinity of the photoconductor 202 charges the surface of the photoconductor 202.

  Laser light corresponding to the image information (signal) of each color is irradiated from the laser exposure device 206 through the mirror 208 on the surface of the photosensitive member 202 charged by the charging device 204, thereby forming an electrostatic latent image.

  The developing device 210 forms a toner image by applying toner to the latent image formed on the surface of the photoreceptor 202. The developing device 210 includes developing devices (not shown) for the respective colors, each containing toners of four colors, cyan, magenta, yellow, and black. Each color toner is applied to the latent image formed on the surface to form a toner image.

  The toner images of the respective colors formed on the surface of the photoconductor 202 are changed in color at the contact portion between the photoconductor 202 and the intermediate transfer body 212 by a bias voltage applied between the photoconductor 202 and the intermediate transfer body 212. Each toner image is transferred onto the outer peripheral surface of the intermediate transfer body 212 so as to coincide with the image information.

The intermediate transfer member 212 has an outer peripheral surface that contacts the surface of the photosensitive member 202 and rotates in the direction of arrow E.
In addition to the photoconductor 202, a transfer roll 214 is provided around the intermediate transfer body 212.

  The intermediate transfer body 212 onto which the multicolor toner image has been transferred rotates in the direction of arrow E. The toner image on the intermediate transfer body 212 is transferred to the surface of the recording medium 15 conveyed to the contact portion in the direction of arrow A by the paper feeding device at the contact portion between the transfer roll 214 and the intermediate transfer body 212.

  The recording medium housed in the paper feeding unit 220 is fed by a recording medium push-up unit (not shown) built in the paper feeding unit 220 to feed the contact portion between the intermediate transfer body 212 and the transfer roll 214. When the recording medium 15 is pushed up to a position where it contacts the roller 222 and contacts the paper feed roller 222, the paper feed roller 222 and the registration roller 224 rotate to convey along the recording medium guide 226 in the direction of arrow A. Is done.

  The recording medium 15 to which the toner image has been transferred is conveyed to the fixing device 100 in the direction of arrow A, and then enters the contact area (nip) between the fixing belt and the pressure member, and the toner image is in a molten state in the recording medium 15. The surface is pressed and fixed on the surface of the recording medium 15. Thereby, an image fixed on the surface of the recording medium is formed.

The surface of the photoconductor 202 after the toner image is transferred to the surface of the intermediate transfer body 212 is cleaned by the cleaning device 216.
The surface of the photoconductor 202 is cleaned by the cleaning device 216 and then discharged by the charge removing device 218.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

[Example 1]
-Fixing belt production-
-Preparation of substrate (PI substrate) N-methyl-2-pyrrolidone (NMP) solution of polyimide precursor (polyimide varnish "U-imide AH", manufactured by Unitika Ltd.) is flow-coated onto a mold with a diameter of 30 mm. Then, the temperature was stepped up to 380 ° C. (25 ° C. → 120 ° C. for 1 hour → 250 ° C. for 1 hour → 380 ° C. for 1 hour → 25 ° C.).
As a result, a seamless resin tubular body made only of polyimide (resin single layer) having an inner diameter of 30 mm, a film thickness of 60 μm, and a width of 400 mm was obtained.

The surface of the obtained tubular seamless resin tubular body was subjected to a surface roughening treatment using a liquid honing apparatus (manufactured by Fuji Seiki, LH-8TTHiS) so that the surface roughness Ra = 0.5 μm or more and 1.0 μm or less. . The honing conditions were as follows: abrasive grain # 320, spray pressure 0.3 MPa, spray distance 100 mm, and processing time 1.5 minutes.
After the abrasive grains on the surface of the roughened seamless resin tubular body were washed away with ion-exchanged water, moisture was removed with compressed air to obtain a PI base material.

-Formation of base metal layer Next, the PI base material was incorporated in a plating jig, and an electroless copper plating layer (base metal layer) having a thickness of 0.5 µm was formed by electroless plating.

-Formation of an electromagnetic induction metal layer After forming an electroless copper plating layer (underlying metal layer), electrodes are set on both ends of the plating jig and subjected to electrolytic plating with a copper sulfate plating solution. A layer (electromagnetic induction metal layer) was formed.

-Formation of a metal protective layer Next, it immersed in the plating solution containing a nickel ion, nickel electroplating was performed, and the 9-micrometer-thick electrolytic nickel layer (metal protective layer) was formed.

-Formation of elastic layer and release layer Next, after applying an adhesive to the surface (outer peripheral surface) of the metal protective layer, liquid silicone rubber (manufactured by Shin-Etsu Chemical Co., Ltd., liquid silicone rubber X-) 34-1053) (thickness 200 μm), primary vulcanization (200 ° C., 20 minutes), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) tube (thickness 30 μm, adhesive layer on the inner surface) ) And adhesive firing (200 ° C., 4 hours) was performed. The formed elastic layer had an Asker C hardness of 42 °.
Thus, after an elastic layer and a release layer were sequentially formed on the outer peripheral surface, both end portions 15 mm were cut off to obtain a fixing belt.

-Configuration of image forming apparatus-
As an image forming apparatus, a product name: Apeos Port-V C7776 manufactured by Fuji Xerox Co., Ltd. having a fixing device having the configuration shown in FIG. 2 was prepared. In the fixing device of this image forming apparatus, the fixing belt is changed to the fixing belt obtained as described above. On the inner peripheral surface of the fixing belt, a pressing member for pressing the fixing belt toward the pressing member and a temperature sensitive magnetic body arranged along the magnetic field generating member are arranged as a sliding member.
On the inner peripheral surface of this fixing belt, an amino-modified silicone oil (X-22-9470, amine equivalent of 35,000 g / mol, manufactured by Shin-Etsu Chemical Co., Ltd., kinematic viscosity at 25 ° C. is 1.0 × 10 ⁻⁴ m ² / s (100 cSt)) was applied. The coating amount was 1.8 × 10 ⁻⁵ g / m ² .

[Comparative Example 1]
In Example 1, the lubricant applied to the inner peripheral surface of the fixing belt is an amino-modified silicone oil manufactured by Shin-Etsu Chemical Co., Ltd. (amine equivalent 100,000 g / mol, kinematic viscosity at 25 ° C. is 3.0 × 10 ^−4. An image forming apparatus was obtained in the same manner as in Example 1 except that m ² / s (300 cSt) was changed.

<Evaluation method>
Belt wear rate The degree of wear on the inner peripheral surface of the fixing belt was evaluated by the wear rate ratio by the following method.
In the image forming apparatus, in a state where the fixing belt is pressurized and heated, the A4 size P paper (manufactured by Fuji Xerox Co., Ltd.) is driven by passing 500,000 sheets in the lateral feed (LEF) direction, and the slide after the driving is performed. The amount of wear of the moving member (pressing member and temperature-sensitive magnetic body), that is, the amount of decrease from the sliding member before driving was measured. The measurement results of the wear amount are converted into ratios using the result in Comparative Example 1 as a reference (1.0), and are shown in Table 1 below.

DESCRIPTION OF SYMBOLS 10 Fixing belt 10A Base material 10B Base metal layer 10C Electromagnetic induction metal layer 10D Metal protective layer 10E Elastic layer 10F Release layer 100 Fixing device 102 Fixing belt 104 Pressure roll (Pressure member)
DESCRIPTION OF SYMBOLS 110 Excitation coil 150 Temperature-sensitive magnetic member 200 Image forming apparatus 202 Photoconductor 204 Charging apparatus 206 Exposure apparatus 210 Development apparatus 212 Intermediate transfer body 214 Transfer roll

Claims (2)

A fixing belt having at least an inner peripheral surface made of a resin material containing polyimide resin;
A pressure member that pressurizes an outer peripheral surface of the fixing belt and sandwiches a recording medium having an unfixed toner image formed on the surface together with the fixing belt;
A sliding member that slides in contact with the inner peripheral surface of the fixing belt;
A lubricant applied to the inner peripheral surface of the fixing belt, comprising at least a lubricating oil having an amine equivalent of 50,000 g / mol or less as a main component, and a kinematic viscosity at 25 ° C. of 2.0 × 10 ^−4. a lubricant that is less than or equal to m ² / s;
A fixing device. An image carrier,
Charging means for charging the surface of the image carrier;
An electrostatic latent image forming means for forming an electrostatic latent image on the surface of the charged image carrier;
Developing means for developing the electrostatic latent image formed on the surface of the image carrier with a developer containing toner to form a toner image;
Transfer means for transferring the toner image to the surface of the recording medium;
The fixing device according to claim 1, wherein the toner image is fixed on the recording medium.
An image forming apparatus comprising: