JP3472286B2 - Fixing belt and image heating fixing device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing belt used in an image forming apparatus such as an electrophotographic apparatus and an electrostatic recording apparatus,
The present invention also relates to an image heating and fixing device that heats and fixes an unfixed image formed and carried on a recording material.

[0002]

2. Description of the Related Art In an image forming apparatus, a recording material (transfer material sheet, electrofax sheet, electrostatic recording paper, OHP sheet, etc.) is used in an image forming process means such as an electrophotographic process, an electrostatic recording process and a magnetic recording process. A heat roller is used as a fixing device that heats and fixes an unfixed image (toner image) of the target image information formed and carried on a printing paper or format paper by a transfer method or a direct method as a permanently fixed image on the recording material surface. The device of the method was widely used. This is generally one that uses a heat source such as a halogen heater in the roller.

On the other hand, as a heating method, a method of heating a resin belt or a metal belt having a small heat capacity by using a ceramic heater as a heat source has been widely proposed and implemented. That is, in the heating method, generally, a heat-resistant belt (fixing belt) is sandwiched between a ceramic heater as a heating body and a pressure roller as a pressure member to form a nip portion, and the nip portion is fixed to the fixing belt. By introducing a recording material on which an unfixed toner image to be fixed with an image is carried between the pressure roller and the belt, the recording material is nipped and conveyed together with the belt, so that the heat of the ceramic heater is transferred to the nip portion via the belt. The heat is applied to the recording material, and the unfixed toner image is thermally and pressure-fixed on the surface of the recording material by the heat and the pressing force of the nip portion.

In this belt heating type fixing device, an on-demand type device can be constructed by using a member having a low heat capacity as a belt. That is, it is sufficient to energize the ceramic heater as a heat source to generate heat at a predetermined fixing temperature only when image formation of the image forming apparatus is performed,
There are advantages that the waiting time from the power-on of the image forming apparatus to the image formation executable state is short (quick start property), and the power consumption during standby is significantly small (power saving).

A heat resistant resin or the like is used as a belt in such a belt heating system, and a polyimide resin excellent in heat resistance and strength is particularly used. However,
Further, when the machine speed is increased and durability is increased, the resin film is insufficient in strength. For this reason, it has been proposed to use a belt having a base layer made of a metal having excellent strength, such as SUS, nickel, aluminum or copper.

Further, Japanese Patent Application Laid-Open No. 7-114276 discloses an induction heating system in which a metal belt is used to generate heat by an eddy current caused by electromagnetic induction. That is, a heating device has been proposed in which an eddy current is generated in the belt itself or a conductive member brought close to the belt by magnetic flux and heat is generated by Joule heat. In this electromagnetic induction heating method, since the heat generation area can be made closer to the object to be heated, the efficiency of energy consumption can be improved.

As a method of driving the fixing belt of the belt heating type fixing device, a film pressed against a pressure guide roller and a film guide for guiding the inner surface of the belt is driven to rotate by the rotation of the pressure roller (pressurization). Roller driving method), and conversely, a method in which a pressure roller is driven to rotate by driving an endless belt stretched by a driving roller and a tension roller.

As a fixing belt using a metal belt,
Japanese Unexamined Patent Publication No. 7-13448 discloses a surface roughness of 0.5 μm.
However, a fixing belt made of nickel having a thickness of about 40 μm or less is used, and in JP-A-6-222695, a coating layer having releasability is provided on the outer peripheral surface and a resin layer is provided on the inner peripheral surface. A nickel fixing belt having a thickness of 10 to 35 μm is exemplified.

Endless belts made of nickel are easily obtained by the nickel electroforming process. Conventionally, the nickel electroforming process has been used for the purpose of improving wear resistance or gloss for decoration, and thus the electroformed nickel thus obtained usually contains a large amount of sulfur. When this nickel electroforming is used for a fixing belt, durability may be problematic due to brittleness at high temperature due to the action of sulfur.

On the other hand, in Japanese Unexamined Patent Publication No. 10-48976, the content of sulfur is set to 0 for the purpose of improving heat resistance and durability.
A fixing belt composed of a nickel metal layer with a manganese content of 04 wt% or less and a manganese content of 0.2 wt% or more has been proposed. Further, Japanese Patent No. 2706432 proposes a fixing belt based on an endless electroformed sheet having a micro Vickers hardness of 450 to 650, which is made of a nickel-manganese alloy containing manganese at 0.05 to 0.6% by weight. .

However, in the case of the belt heating method, particularly the belt heating method using a metal belt, the belt is repeatedly bent at the nip portion and its entrance / exit as the belt itself rotates, and mechanical fatigue easily occurs. The problem of heat resistance and durability is still a concern.

[0012]

SUMMARY OF THE INVENTION The present invention provides an image heating apparatus capable of low energy heating by using a heating body having a small heat capacity, and a fixing belt having high durability and high durability and reliability. An object is to provide a high image heating device.

[0013]

A fixing belt according to the present invention has at least a release layer and a nickel electroformed metal layer, and nickel electroformed has a crystal orientation of (200 ) plane preferential growth .
It is characterized by having.

[0014]

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The fixing belt of the present invention is at least
Also has a release layer and a nickel electroformed metal layer,
In electroforming, crystal growth is (200) plane preferential growth and crystal orientation
Ratio I₍₂₀₀₎/ I_{(1 11)}Is 3 or more, Micro Vickers
The hardness is 280 to 450. Crystal orientation ratio I₍₂₀₀₎/ I
₍₁₁₁₎Is more preferably 8 or more. Also, my
It is more preferable that the crovicers hardness is 330 to 420
preferable. Here, nickel electroforming refers to the electroforming process.
Refers to nickel and its alloys formed by

The (200) plane preferential growth of the present invention means preferential crystal growth in the (200) direction parallel to the master surface. The crystal orientation ratio I ₍₂₀₀₎ / I ₍₁₁₁₎ is (200)
X-ray diffraction intensity ratio of (111) and I ₍₂₀₀₎ / I ₍₁₁₁₎
Is defined by The d value of the (200) plane is 1.761.
9Å, and the d value of the (111) plane is 2.0345Å.

Conventionally, in general electroformed nickel, the crystal structure is (111) plane preferential growth. As a result, the gloss and hardness of the surface are secured, and it is used for decoration or sliding surfaces. Therefore, conventionally, even in the fixing belt, the electroformed nickel of (111) plane preferential growth has been used. On the other hand, in the present invention, electroformed nickel whose crystal growth is (200) plane preferential growth is used, which improves the durability of the fixing belt. If the crystal growth is (200) plane preferential growth, it is advantageous in terms of flexibility and is suitable for a fixing belt that requires flexibility.

When the crystal orientation ratio I ₍₂₀₀₎ / I ₍₁₁₁₎ is small, the reason is not clear, but sulfur and organic substances due to the brightening agent in the electrolytic bath co-deposit with nickel crystal growth. Therefore, it is disadvantageous in high temperature durability, and since the structure of electroformed nickel tends to be fine crystals, the hardness becomes high, which may cause a problem in flexibility of the belt. In the present invention, by setting the crystal orientation ratio I ₍₂₀₀₎ / I ₍₁₁₁₎ to 3 or more, sufficient durability can be secured.

On the other hand, the electrocast micro Vickers hardness is 2
If it is less than 80, it is difficult to handle because the rigidity is low,
For example, wrinkles are generated due to the load at the time of demolding from the mother die, and the stability in the working process is poor. When the electrocast micro Vickers hardness is more than 450, the flexibility of the belt is poor and the belt may not be suitable as a fixing belt.

The nickel electrocasting has sufficient heat resistance as a fixing belt.

Regarding the conventional semi-bright or matte electroformed nickel, for example, the X-ray diffraction pattern of the semi-bright and matte nickel is described on page 338 of the latest surface technology (published by Industrial Technology Service Center Co., Ltd.). According to this, although the (200) plane preferential growth is clear, in this case, it is only used for a special purpose such as an undercoat of gold plating, and there is no example using it for a fixing belt.

(1) Fixing belt 10 Next, the fixing belt of the present invention will be described.

FIG. 1 is an example of a layer structure model diagram of the fixing belt 10 in this embodiment. The fixing belt 10 of this example includes a metal layer 1 made of a nickel electroformed endless belt as a base layer, an elastic layer 2 laminated on the outer surface thereof, a release layer 3 further laminated on the outer surface thereof, and an inner surface of the metal layer 1. It has a composite structure with the sliding layer 4 laminated on. In the fixing belt 10, the sliding layer 4
Is the inner surface side (belt guide surface side), and the release layer 3 is the outer surface side (pressure roller surface side). A primer layer (not shown) is provided for adhesion between the metal layer 1 and the elastic layer 2, between the elastic layer 2 and the release layer 3, or between the metal layer 1 and the sliding layer 4. May be. The primer layer may be a known one such as silicone type, epoxy type, polyamide imide type and the like, and the thickness thereof is usually about 1 to 10 μm.

FIG. 2 is an example of a layer structure model diagram of the fixing belt 10 'in this example. This is an example in which an elastic layer is not provided. The fixing belt 10 'of this example comprises a metal layer 1'made of a nickel electroformed endless belt as a base layer, a release layer 3'laminated on the outer surface thereof, and a sliding layer 4 laminated on the inner surface of the metal layer 1'. 'Has a composite structure with. In the fixing belt 10 ′, the sliding layer 4 ′ is the inner surface side (belt guide surface side) and the release layer 3 ′ is the outer surface side (pressure roller surface side). Between the metal layer 1'and the release layer 3'or between the metal layer 1 and the sliding layer 4, there is a primer layer (not shown) for adhesion.
May be provided. The primer layer is the fixing belt 10 of FIG.
The same as the above may be provided. In particular, in the case of heating and fixing a monochrome image in which the amount of toner on the recording material is small and the unevenness of the toner layer is relatively small, such an elastic layer can be omitted.

When this fixing belt is used in an electromagnetic induction heating system, the metal layer 1 or 1'made of a nickel electroformed endless belt functions as a heat generating layer exhibiting electromagnetic induction heat generation.
As will be described later, when an alternating magnetic flux acts on the metal layer 1 or 1 ', an eddy current is generated in the metal layer 1 or 1'.
Or 1'heats up. The heat heats the fixing belt 10 or 10 'through the elastic layer 2 / releasing layer 3 or the releasing layer 3', and heats the recording material passed through the fixing nip portion N to heat the toner image. It is fixed.

Further, the fixing belt 10 or 1 of the present invention
0'may be used for a belt heating method using a ceramic heater. As will be described later, in this case, the heat of the ceramic heater is applied to the recording material via the fixing belt 10 or 10 ', and the toner image is heated and fixed on the surface of the recording material.

A. Metal layer 1 The metal layer 1 is obtained by immersing a columnar mold such as SUS in an electroforming bath.
It consists of nickel (including alloys) grown on the surface of the master mold by an electroforming process. In this nickel electroforming, the crystal growth is (200) plane preferential growth, the crystal orientation ratio I ₍₂₀₀₎ / I ₍₁₁₁₎ is 3 or more, and the micro Vickers hardness is 280 to 450. The crystal orientation ratio I ₍₂₀₀₎ / I ₍₁₁₁₎ is more preferably 8 or more, and particularly preferably 25 or more. The micro Vickers hardness is more preferably 330 or more or 42.
It is 0 or less, and particularly preferably 330 to 420.

The content of precipitated sulfur in nickel electroforming is preferably 0.03 mass% or less, and more preferably 0.02 mass% or less. The sulfur component of nickel electroforming is an essential component that reduces electrodeposition stress and improves molding accuracy.
On the other hand, it impairs flexibility and elasticity at high temperatures, and is closely involved in the fracture phenomenon due to metal fatigue. If too much sulfur is present, the sulfur forms a thin brittle film around the nickel grain boundaries at high temperatures, and the nickel electroforming grain boundaries may become discontinuous, which may easily cause brittle fracture. . If the amount of sulfur is too small, the releasability from the mother mold may decrease, and the lower limit of the sulfur content is usually 0.0001.
The amount is about% by mass, preferably about 0.001% by mass.

The crystal orientation ratio I ₍₂₀₀₎ / I ₍₁₁₁₎ has a great influence on the contents of the deposited sulfur and carbon, and the ratio thereof. That is, when the content of sulfur is 0.03 mass% or less, the content of carbon element is 2% of the content of sulfur.
If it is more than the mass times, (200) plane preferential growth with a crystal orientation ratio I ₍₂₀₀₎ / I ₍₁₁₁₎ of 3 or more will be obtained. The content of the carbon element in nickel electroforming is preferably 0.08 mass% or less. If the carbon element is too much, the internal stress may increase and floating from the matrix may occur, so that stable crystal growth may not be expected.

Further, the content of manganese in nickel electroforming is 0.2 mass times or more, particularly 3 mass times or more, and preferably 10 mass times or less, of the sulfur content. Addition of an appropriate amount of manganese suppresses brittleness of nickel electroforming at high temperature due to sulfur. It is considered that this is because the sulfur-manganese compound is formed at the crystal grain boundaries and the formation of the sulfur brittle film around the grain boundaries is suppressed. If the manganese content is too low, it may be difficult to obtain the effect of suppressing the brittle behavior of sulfur. Further, if the content of manganese is too large, manganese may segregate at the nickel grain boundaries, which may cause a disadvantage that the toughness of the material decreases.

When the contents of sulfur, carbon element and manganese are within such ranges, the crystal growth of electroformed nickel is (200) plane preferential growth and the crystal orientation ratio I ₍₂₀₀₎ / I
_It is easy to take a crystal form in which ₍₁₁₁₎ is 3 or more. Further, when the sulfur content is low, the crystal growth tends to be (200) plane preferential growth.

The content of cobalt in nickel electroforming is preferably 0.1 times by mass or more, more preferably 0.2 times by mass or more, and 5 times by mass or less, especially 1.5 times by mass, that of sulfur. The following is preferable. In nickel electroforming, cobalt suppresses embrittlement due to sulfur and also serves as a crystal nucleus. If the content of cobalt is too large, inconveniences such as an increase in hardness and a decrease in toughness due to fine crystals may occur.

The nickel electroforming may further contain tungsten or the like. The content is preferably 0.5% by mass or less.

Nickel electroforming is produced by an electroforming process using, for example, a mother die made of stainless steel as a cathode. As the electrolytic bath in this case, for example, a known nickel electrolytic bath such as a sulfamic acid system can be used.
Additives such as an H-adjusting agent, a pit preventing agent, and a brightening agent may be added as appropriate. For example, nickel sulfamate is 300
˜450 g / l, nickel chloride 0 to 30 g / l, and boric acid 30 to 45 g / l. Then, by controlling the temperature of the electrolytic bath, the cathode current density, etc., nickel electroforming comprising desired nickel or nickel alloy can be obtained. Although the electroforming process varies depending on the electrolytic bath used, it is usually preferable to carry out at an electrolytic bath temperature of about 45 to 60 ° C. and a cathode current density of about 1 to 10 A / dm ² . Nickel produced by the electroforming process is a stress reducing agent / primary brightener containing saccharin, sodium benzenesulfonate, sodium naphthalenesulfonate, etc. in the electrolytic bath, and a secondary brightening agent containing 2-butyne-1,4 diol, coumarin, diethyltriamine, etc. By adding an additive referred to as, the electrodeposition stress is reduced and the molding accuracy is improved. By adjusting the amount of additive added at this time,
The amount of sulfur and the amount of carbon element during nickel electroforming can be set within the above ranges, and usually 0.01 g / l to
It is preferable to add about 1 g / l.

The contents of sulfur and carbon deposited are
Concentration of brighteners (saccharin, butynediol) in the bath,
Also, it can be adjusted under process conditions such as current density and bath temperature.

As a method of adding manganese during nickel electroforming, there may be mentioned a method in which manganese fine particles, manganese sulfamate and the like are put in a nickel electrolytic solution and electroplating is carried out in a well-stirred state. Although the amount of the manganese compound to be added varies depending on the intended composition, it is usually preferable to add it in an aqueous solution (about 50% by mass) in advance and add about 10 ml / l or less.

As a method of adding cobalt during nickel electroforming, there may be mentioned a method of adding cobalt sulfate, cobalt chloride, cobalt sulfamate or the like to a nickel electrolytic solution, and electroplating in a well-stirred state. The amount of the cobalt compound to be added depends on the intended composition,
Usually, it is 5 ml when it is made into an aqueous solution (about 50% by mass) in advance.
It is preferable to add about 1 / l or less.

The thickness of the metal layer 1 is thicker than the skin depth expressed by the following equation, and preferably 1 μm or more,
Further, it is preferably 200 μm or less, and particularly preferably 100 μm or less. The skin depth σ [m] is the frequency f of the excitation circuit.
[Hz], magnetic permeability μ, and specific resistance ρ [Ωm] are expressed as σ = 503 × (ρ / fμ) ^1/2 . This shows the depth of absorption of electromagnetic waves used in electromagnetic induction. At deeper levels, the intensity of electromagnetic waves is less than 1 / e. Conversely, most energy is absorbed up to this depth. (Fig. 3). If the metal layer 1 is too thin, most of the electromagnetic energy can no longer be absorbed and efficiency may deteriorate. Further, if the metal layer 1 is too thick, the rigidity becomes high, and the bending property becomes poor, which may make it difficult to use as a rotating body. Further, in the case of using the belt heating method using a ceramic heater, in order to reduce the heat capacity and improve the quick start property, the film thickness is 100 μm.
m or less, particularly 50 μm or less, and preferably 20 μm or more.

The nickel electroforming used in the present invention is usually crystalline, but may partially contain amorphous. Further, the crystal is preferably not a fine crystal in terms of hardness and flexibility.

Vickers hardness HV280 used in the present invention
The nickel electroforming of No. 450 to 450 has a sufficient heat resistance as a fixing belt, and thus the reduction rate of Vickers hardness when heated to 450 ° C. is preferably 20% or less.

Further, the nickel electroforming preferably has a recrystallization temperature of 450 ° C. or higher from the viewpoint of having sufficient heat resistance as a fixing belt.

Further, in nickel electroforming, the tensile strength at room temperature is preferably 700 to 1500 MPa, and the elongation is 2
-8% is preferable. From the viewpoint of having sufficient heat resistance as the fixing belt, it is preferable that the characteristic deterioration rate when heated to 450 ° C. is 20% or less.

B. Elastic Layer 2 The elastic layer 2 may or may not be provided. By providing the elastic layer, it is possible to cover the heated image in the nip portion to ensure heat transfer, and to supplement the restoring force of the nickel electroformed belt to reduce fatigue due to rotation and bending. Further, by providing the elastic layer, the followability of the surface of the releasing layer of the fixing belt to the surface of the unfixed toner image is increased, and the heat can be efficiently transferred. The fixing belt provided with the elastic layer 2 is particularly suitable for heat fixing of a color image having a large amount of unfixed toner.

The material of the elastic layer 2 is not particularly limited, and one having good heat resistance and good thermal conductivity may be selected.
As the elastic layer 2, silicone rubber, fluororubber, fluorosilicone rubber or the like is preferable, and silicone rubber is particularly preferable.

As the silicone rubber used for the elastic layer, polydimethylsiloxane, polymethyltrifluoropropylsiloxane, polymethylvinylsiloxane,
Examples thereof include polytrifluoropropylvinyl siloxane, polymethylphenyl siloxane, polyphenyl vinyl siloxane, and copolymers of these polysiloxanes.

If necessary, the elastic layer may have a reinforcing filler such as dry silica or wet silica, calcium carbonate, quartz powder, zirconium silicate, clay (aluminum silicate), talc (hydrous magnesium silicate), alumina ( Aluminum oxide), red iron oxide (iron oxide), etc. may be contained in the elastic layer.

The thickness of the elastic layer 2 is preferably 10 μm or more, more preferably 50 μm or more, and preferably 1000 μm or less, especially 500 μm or less, since good fixed image quality can be obtained. When printing a color image, a solid image is formed over a large area on the recording material P, especially for a photographic image or the like. In this case, if the heating surface (release layer 3) cannot follow the unevenness of the recording material or the unevenness of the toner layer, heating unevenness occurs, and uneven glossiness occurs in the image between a portion having a large amount of heat transfer and a portion having a small amount of heat transfer. That is, the glossiness is high in the portion where the heat transfer amount is large, and the glossiness is low in the portion where the heat transfer amount is small. If the elastic layer 2 is too thin, it may not be possible to follow the irregularities of the recording material or the toner layer, and uneven image gloss may occur. In addition, if the elastic layer 2 is too thick, the thermal resistance of the elastic layer increases, which may make it difficult to realize a quick start.

The hardness (JIS-A) of the elastic layer 2 is preferably 60 ° or less, and particularly preferably 45 ° or less, because the occurrence of image gloss unevenness is sufficiently suppressed and a good fixed image quality is obtained.

The thermal conductivity λ of the elastic layer 2 is 2.5 × 10 ^-3
[W / cm · ° C.] or higher, especially 3.3 × 10 ⁻³ [W / cm
· ° C] or higher is preferable, and 8.4 × 10 ⁻³ [W / cm ·
C.] or lower, particularly preferably 6.3.times.10.sup.- ³ [W / cm.degree. C.] or lower. When the thermal conductivity λ is too small, the thermal resistance becomes large and the surface layer of the fixing film (release layer 3)
The temperature rise at may slow down. If the thermal conductivity λ is too large, the hardness may be high or the compression set may be deteriorated.

Such an elastic layer is formed by a known method, for example, a method of coating a material such as liquid silicone rubber on the metal layer with a uniform thickness by means of a blade coating method or the like and heating and curing it; liquid silicone rubber It may be formed by a method of injecting materials such as the above into a mold and vulcanizing and curing; a method of vulcanizing and curing after extrusion molding; a method of vulcanizing and curing after injection molding.

C. Release Layer 3 The material of the release layer 3 is not particularly limited, and a material having good releasability and heat resistance may be selected. As the release layer 3, PFA is used.
(Tetrafluoroethylene / perfluoroalkyl ether copolymer), PTFE (polytetrafluoroethylene), FEP (tetrafluoroethylene / hexafluoropropylene copolymer), fluororesin, silicone resin, fluorosilicone rubber, fluororubber, Silicone rubber is preferable, and PFA is particularly preferable.

If necessary, the release layer may contain a conductive agent such as carbon or tin oxide in an amount of 10% by mass or less of the release layer.

The release layer 3 has a thickness of 1 μm or more or 100
μm or less is preferable. If the release layer 3 is too thin, the coating may have uneven coating to form a part with poor releasability, or the durability may be insufficient. Further, if the release layer is too thick, heat conduction may deteriorate, and especially in the case of a resin-based release layer, the hardness may be high and the effect of the elastic layer 2 may be lost.

Such a release layer is formed by a known method, for example,
In the case of a fluororesin type, it may be formed by a method of coating / drying / firing a fluororesin powder made into a dispersion paint, or by coating / adhering a tube type in advance, and in the case of a rubber type, a liquid type It may be formed by a method of injecting a material into a molding die and vulcanizing and curing it; a method of vulcanizing and curing after extrusion molding; a method of vulcanizing and curing after injection molding.

Further, a tube whose inner surface has been subjected to a primer treatment and a nickel electroformed belt which has been subjected to a surface primer treatment in advance are mounted in a cylindrical mold, and liquid silicone rubber is injected between the tube and the nickel electroformed belt and heated. It is also possible to form the elastic layer and the release layer at the same time by using the method of curing and adhering the rubber in Step 1.

D. Sliding Layer 4 Although the sliding layer 4 is not an essential component of the present invention, it is preferably provided in order to reduce the drive torque when operating the image heating and fixing device of the present invention. When the sliding layer 4 is provided, the heat generated in the heat generating layer 1 can be insulated so as not to go to the inside of the fixing belt without excessively increasing the heat capacity of the fixing belt. Recording material P
The efficiency of heat supply to the side is improved, and power consumption can be suppressed. Also, the rise time can be shortened.

The material is not particularly limited, and one having high heat resistance, high strength and smooth surface may be selected.
The sliding layer 4 is preferably made of polyimide resin or the like.

If necessary, the sliding layer may contain fluororesin powder, graphite, molybdenum disulfide, etc. as a sliding agent.

The thickness of the sliding layer 4 is preferably 5 μm or more, more preferably 10 μm or more, and 100 μm or less, especially 60 μm.
m or less is preferable. If the sliding layer 4 is too thin, the durability may be insufficient. If the sliding layer 4 is too thick, the heat capacity of the fixing belt becomes large and the rising time may become long.

Such a sliding layer can be formed by a known method, for example,
It may be formed by a method of coating / drying / curing a liquid material, or a method of attaching a tube-shaped material in advance.

(2) Image Heat Fixing Device 100 Next, the image heat fixing device of the present invention will be described. The image heating and fixing device of the present invention has a fixing belt and a pair of pressure contact members that are in pressure contact with each other via the fixing belt, and the inner surface of the fixing belt slides on one of the pressure contact members to form the fixing belt. An image on a recording material is heated and fixed by heat from the fixing belt, and the fixing belt used is the above-mentioned fixing belt of the present invention. In particular, it has a magnetic flux generating means for generating a magnetic flux, and the magnetic flux generated by this magnetic flux generating means heats the fixing belt to heat and fix the image on the recording material, or slide with the fixing belt. It is preferable that the pressing member is a heating body, and an image heating fixing device that heats and fixes the image on the recording material by heat from the heating body via the fixing belt.

(First Embodiment) FIG. 4 is an example of a cross-sectional model view of a main part of the image heating and fixing device 100 of this embodiment. In this example, the image heating and fixing device 100 is an electromagnetic induction heating type device, and the fixing belt 10 is of the above-described present invention.

The magnetic field generating means is the magnetic core 17 (a to c).
And an exciting coil 18. FIG. 5 is a model diagram of the magnetic field generating means of this image heating apparatus.

The magnetic core 17 is a member having a high magnetic permeability and is preferably made of a material such as ferrite or permalloy that is used for the core of a transformer. Particularly, it is preferable to use ferrite which causes little loss even at 100 kHz or more.

The exciting coil 18 is a bundle of a plurality of thin copper wires, each of which is insulation-coated, as a conducting wire (electric wire) forming a coil (a coil), and is wound a plurality of times. To form an exciting coil. In this example, the exciting coil 18 is formed by winding 11 turns.

As the insulating coating, it is preferable to use a coating having heat resistance in consideration of heat conduction due to heat generation of the fixing belt 10. For example, a coating of polyimide resin, polyamide-imide resin, or the like is used. Here, pressure may be applied from the outside of the exciting coil 18 to improve the density.

An insulating member 19 is arranged between the magnetic field generating means and the fixing belt 10. As a material of the insulating member 19, a material having excellent insulating property and good heat resistance is preferable. For example,
Phenol resin, fluororesin, polyimide resin, polyamide resin, polyamideimide resin, PEEK (polyether ether ketone) resin, PES (polyether sulfone) resin, PPS (polyphenylene sulfide) resin, PFA ((tetrafluoroethylene / perfluoroalkyl) Ether copolymer) resin, PTFE (polytetrafluoroethylene) resin, FEP (tetrafluoroethylene / hexafluoropropylene copolymer) resin, L
CP (liquid crystal polyester) resin and the like are preferable.

The exciting coil 18 has power feeding portions 18a and 18b.
An exciting circuit 27 is connected to the. This exciting circuit 27
Preferably, a switching power supply can generate a high frequency of 20 kHz to 500 kHz. The exciting coil 18 generates an alternating magnetic flux by the alternating current (high frequency current) supplied from the exciting circuit 27.

FIG. 6 schematically shows how alternating magnetic flux is generated. The magnetic flux C represents a part of the generated alternating magnetic flux.

Alternating magnetic flux (C) guided to the magnetic core 17
Generates an eddy current in the metal layer (electromagnetic induction heating layer) 1 made of nickel electroforming of the fixing belt 10. This eddy current is generated due to the specific resistance of the electromagnetic induction heating layer 1
Generates Joule heat (eddy current loss). The heat generation amount Q here is determined by the density of the magnetic flux passing through the electromagnetic induction heating layer 1, and exhibits a distribution as shown in the graph of FIG. In the right diagram of FIG. 6, the vertical axis represents the position of the electromagnetic induction heating layer by an angle θ, and the horizontal axis represents the heat generation amount Q in the electromagnetic induction heating layer 1 of the fixing belt 10. Here, in the heat generation region H, when the maximum heat generation amount is Q, the heat generation amount is Q
Defined as a region of / e or more. This is an area where the amount of heat generated for fixing can be obtained.

The temperature of the fixing nip portion N is controlled so that a predetermined temperature is maintained by controlling the current supply to the exciting coil 18 by a temperature control system including a temperature detecting means (not shown). The temperature sensor 26 shown in FIG.
The temperature of the fixing nip portion N is controlled based on the temperature information of the fixing belt 10 measured by the temperature sensor 26 in this example.

The pressure roller 30 as a pressure member comprises a cored bar 30a and a layer of heat-resistant and elastic material such as silicone rubber, fluororubber, fluororesin, etc., which is formed by concentrically molding and covering the cored bar into a roller shape. 30b and a cored bar 30
Both ends of a are rotatably supported by bearings between chassis side metal plates (not shown) of the apparatus.

By compressing the pressure springs (not shown) between both ends of the pressure rigid stay 22 and the spring receiving member (not shown) on the apparatus chassis side, the pressure component stay 2 is formed.
2 is being pushed down. As a result, the lower surface of the sliding plate 40 disposed on the lower surface of the belt guide member 16a and the upper surface of the pressure roller 30 are pressed against each other with the fixing belt 10 sandwiched therebetween to form the fixing nip portion N having a predetermined width. The belt guide member 16 is made of heat-resistant phenol resin, LC
It is preferable to use a resin having excellent heat resistance such as a P (liquid crystal polyester) resin, a PPS (polyphenylene sulfide) resin, and a PEEK (polyether ether ketone) resin.

The pressure roller 30 is driven to rotate counterclockwise by the driving means M as shown by the arrow. The pressure roller 30 and the fixing belt 10 are driven by the rotation of the pressure roller 30.
A rotational force acts on the fixing belt 10 by a frictional force between the fixing belt 10 and the inner surface of the fixing belt 10 sliding on the lower surface of the sliding plate 40 at the fixing nip portion N, and the fixing belt 10 is applied in a clockwise direction as shown by an arrow. The outer circumference of the belt guide members 16a and 16b is rotated at a peripheral speed substantially corresponding to the rotational speed of the pressure roller 30.

In this way, the pressure roller 30 is rotationally driven, the fixing belt 10 is rotated accordingly, and the exciting circuit 2 is rotated.
The electromagnetic induction heat generation of the fixing belt 10 is performed as described above by the power feeding from the excitation coil 18 to the exciting coil 18, and the fixing nip portion N is heated to a predetermined temperature and is temperature-controlled. The recording material P on which the formed toner image t is formed is fixed to the fixing belt 10 in the fixing nip portion N.
The image surface is introduced between the pressure roller 30 and the pressure roller 30 facing upward, that is, facing the fixing belt surface. Then, in the fixing nip portion N, the image surface is brought into close contact with the outer surface of the fixing belt 10,
The fixing nip portion N is nipped and conveyed together with the fixing belt 10. In this process, the unfixed toner image t is heated and fixed on the surface of the recording material P by being heated by the electromagnetic induction heat generation of the fixing belt 10. When the recording material P passes through the fixing nip portion N, it is separated from the outer surface of the rotary fixing belt 10 and discharged and conveyed. The heat-fixed toner image on the recording material passes through the fixing nip portion N and is then cooled to become a permanently fixed image.

In this embodiment, the fixing device is not provided with an oil coating mechanism for preventing offset, but when a toner containing no low-softening substance is used, an oil coating mechanism may be provided. Further, even when a toner containing a low-softening substance is used, oil coating or cooling separation may be performed.

The pressing member 30 is not limited to the roller body,
It is also possible to use other types of members such as a turning film type.
Further, in order to supply heat energy to the recording material also from the pressure member 30 side, a heat generating means such as electromagnetic induction heating is also provided on the pressure member 30 side to provide an apparatus configuration for heating and controlling the temperature to a predetermined temperature. You can also do it.

(Second Embodiment) The fixing belt of the present invention can also be preferably used in a belt heating type fixing device using a ceramic heater as a heating element.

FIG. 7 shows an image heating and fixing device 100 in this example.
It is an example of a cross-sectional model view of. In this example, the image heating and fixing device 100 is a belt heating type device using a ceramic heater as a heating body, and the fixing belt 10 is that of the present invention described above.

The belt guide 16c is a heat resistant and heat insulating belt guide. Ceramic heater 1 as heating element
Reference numeral 2 is fixedly supported by being fitted in a groove portion formed along the length of the guide substantially in the center of the lower surface of the belt guide 16c. The cylindrical or endless fixing belt 10 of the present invention is loosely fitted onto the belt guide 16c.

The pressurizing rigid stay 22 is made up of the belt guide 16
It is inserted inside c.

The pressure member 30 is an elastic pressure roller in this example. The pressurizing member 30 has a core metal 30a provided with an elastic layer 30b of silicone rubber or the like to reduce the hardness, and both ends of the core metal 30a are connected to a chassis side plate on the front side and the rear side (not shown) of the device. The bearings are rotatably held between them. The elastic pressure roller further includes PTFE (polytetrafluoroethylene), PFA (tetrafluoroethylene / perfluoroalkyl ether copolymer), FEP (tetrafluoroethylene / hexafluoropropylene copolymer) on the outer periphery in order to improve the surface property. A fluororesin layer such as a polymer) may be provided.

The pressing means for forming the fixing nip portion N and the holding means for holding the end portion of the fixing film have the same structure as in the first embodiment.

The pressure roller 30 is rotationally driven by the driving means M in the counterclockwise direction as shown by the arrow. The pressure roller 30 and the fixing belt 10 are driven by the rotation of the pressure roller 30.
A rotational force acts on the fixing belt 10 by the frictional force between the fixing belt 10 and the outer surface of the fixing belt 10, and the inner surface of the fixing belt 10 slides in close contact with the lower surface of the ceramic heater 12 at the fixing nip portion N, as shown by the arrow. The belt guide 16c is rotated outward in the clockwise direction at a peripheral speed substantially corresponding to the rotational peripheral speed of the pressure roller 30 (pressure roller driving method).

The pressure roller 30 starts to rotate based on the print start signal, and the ceramic heater 12 starts to heat up. When the rotation peripheral speed of the fixing belt 10 is stabilized by the rotation of the pressure roller 30 and the temperature of the ceramic heater 12 rises to a predetermined temperature, the fixing belt 10 in the fixing nip portion N and the pressure roller 30 are heated.
The recording material P carrying the toner image t as the material to be heated is introduced between the fixing belt 10 and the toner image carrying surface side. Then, the recording material P adheres to the lower surface of the ceramic heater 12 through the fixing belt 10 in the fixing nip portion N, and together with the fixing belt 10, the fixing nip portion N.
Move through. In the course of the movement, the heat of the ceramic heater 12 is applied to the recording material P via the fixing belt 10, and the toner image t is heated and fixed on the surface of the recording material P. The recording material P that has passed through the fixing nip portion N is separated from the outer surface of the fixing belt 10 and conveyed.

The ceramic heater 12 as the heating element is
It is a horizontally elongated linear heating element having a low heat capacity and having a longitudinal direction in a direction orthogonal to the moving direction of the fixing belt 10 and the recording material P. A heater substrate 12a made of aluminum nitride or the like and a heating layer 12b provided on the surface of the heater substrate 12a along its length, for example, an electric resistance material such as Ag / Pd (silver / palladium) having a width of about 10 μm and a width of 1 μm. The basic structure is a heating layer 12b coated by screen printing or the like to 5 mm and a protective layer 12c such as glass or fluororesin provided thereon. The ceramic heater used is not limited to this.

Then, the heating layer 1 of the ceramic heater 12
The heat generation layer 12b generates heat by being energized between both ends of 2b, and the heater 12 rapidly rises in temperature. The heater temperature is detected by a temperature sensor (not shown), and the heating layer 12 is controlled by a control circuit (not shown) so that the heater temperature is maintained at a predetermined temperature.
The energization of b is controlled and the temperature of the heater 12 is controlled.

The ceramic heater 12 is the belt guide 1
The protective layer 12c side is fitted upward and fixedly supported in a groove portion formed along the longitudinal direction of the guide at a substantially central portion of the lower surface of 6c. The surface of the sliding member 40 of the ceramic heater 12 and the inner surface of the fixing belt 10 slide in contact with each other at the fixing nip portion N that contacts the fixing belt 10.

Further, a ferromagnetic metal plate such as an iron plate may be provided in place of the ceramic heater, and the ferromagnetic metal plate may be heated by the electromagnetic induction used in the first embodiment to be used as a heater. .

The pressure member 30 is not limited to the roller body,
It is also possible to use other types of members such as a turning film type.
Further, in order to supply heat energy to the recording material also from the pressure member 30 side, a heat generating means such as electromagnetic induction heating is also provided on the pressure member 30 side to provide an apparatus configuration for heating and controlling the temperature to a predetermined temperature. You can also do it.

(Other Embodiments) The apparatus configuration of the image heating and fixing device is not limited to the pressure roller driving system of the above embodiment.

Besides, as shown in FIG. 8, for example, the belt guide 16, the driving roller 31, and the tension roller 32 are provided.
The fixing belt 10 of the present invention is stretched between the fixing belt 10 and the lower surface of the belt guide 16 and the pressure roller 30 as a pressure member.
And nip it on the fixing belt 10 and press-contact them to fix the nip portion N.
Can be formed, and the fixing belt 10 can be rotationally driven by the driving roller 31. In this case, the pressure roller 30 is a driven rotation roller.

Also in this case, the pressing member 30 is not limited to the roller body, but may be a member of other forms such as a rotating film type. Further, in order to supply heat energy to the recording material also from the pressure member 30 side, a heat generating means such as electromagnetic induction heating is also provided on the pressure member 30 side to provide an apparatus configuration for heating and controlling the temperature to a predetermined temperature. You can also do it.

The image heating apparatus of the present invention is not limited to the image heating and fixing apparatus, but may be an image heating apparatus for heating a recording material carrying an image to modify the surface properties of gloss or the like, or an assumed image heating apparatus. Can be used as In addition, it can be widely used as a heating / drying device for a material to be heated, a heating laminating device, and the like, as a means and a device for heat-treating a material to be heated.

[0095]

[Experimental Example 1] A nickel electroformed endless belt shown in Table 1 having an inner diameter of 34 mm and a thickness of 50 μm was selected as the metal layer 1, and a silicone rubber having a thickness of 300 μm was used as the elastic layer 2.
A PFA tube having a thickness of 30 μm was laminated as a release layer 3 via a primer, and a sliding layer 4 having a thickness of 1 was used.
Various fixing belts were prepared by laminating 5 μm polyimide resin layers.

First, as an electrolytic bath, nickel sulfamate tetrahydrate 450 g / l, nickel chloride 10 g / l, boric acid 4
After making a 0 g / l aqueous solution bath, and then adding the required amount of pit inhibitor, saccharin and 2-butyne-1,4-as brighteners.
The diol was added in the amount shown in Table 1 below. Furthermore, as other additives, manganese sulfamate aqueous solution (50% by weight) and cobalt chloride aqueous solution (50% by weight) were added in the amounts shown in Table 1 below, and electrolytic purification was performed at a low current while filtering with a container filled with activated carbon. Was done. Using the various nickel electrolysis baths obtained, nickel electroforming was performed at a temperature of various electrolysis baths and cathode current densities shown in Table 1 below, using a stainless steel matrix as a cathode, and nickel electroforming with an inner diameter of 34 mm and a thickness of 50 μm. Was deposited. Then, this nickel electroformed was removed from the mother die to form a metal layer.

[0097]

[Table 1]

The crystal orientation ratio I _{(200) of the} obtained nickel electroforming
/ I ₍₁₁₁₎ is an X-ray diffractometer RAD- manufactured by Rigaku Denki Co., Ltd.
Wide angle X-ray scattering diffraction method using 3R type, (200) plane (d value = 1.7619Å) and (111) plane (d value = 2.0)
The X-ray diffraction intensity of 345Å) was measured and determined from the ratio.

The contents of sulfur, manganese, and cobalt in nickel electroforming are determined by inductively coupled plasma emission spectrometry (I
CP-AES). Inductively coupled plasma optical emission spectrometry is a method for quantifying elements by measuring the intensity of the emission line corresponding to the wavelength of photons emitted when a thermally excited atom (or ion) returns to a low energy level. Is to do.

The carbon content in nickel electroforming was quantified by the combustion-infrared absorption method. In the combustion-infrared absorption method, a sample is put in a magnetic crucible, a combustion improver is added, high frequency induction heating or electric resistance heating is performed in an oxygen stream to burn, and sufficient oxidation is performed to convert C in the sample to CO ₂ . By measuring the amount of absorption of infrared rays by CO ₂ through infrared detection of the combustion gas and comparing it with the value measured by a standard sample, C
Is quantified.

The results are shown in Table 2.

[0102]

Next, a primer (DY35-manufactured by Toray Dow Corning Silicone Co., Ltd.) was previously formed on the metal layer.
051) was applied by spraying and dried at 150 ° C. for 30 minutes to form a primer layer. Its thickness is 5μ
It was m.

Next, a primer layer is formed on the inner surface of the PFA tube in the same manner, and the primer layer is coaxially mounted together with the above metal layer in a cylindrical mold having an inner diameter substantially the same as the outer diameter of the PFA tube to form a liquid between the tube and the metal layer. Silicone rubber (Toray Dow Corning Silicone: DY32-561A / B)
And heated at 200 ° C. for 30 minutes in a hot air circulation furnace.
Curing of the rubber and adhesion of each layer were performed simultaneously, and a silicone rubber having a thickness of 300 μm as the elastic layer 2 and a PFA tube having a thickness of 30 μm as the release layer 3 were laminated on the metal layer.

On the opposite surface of the metal layer, a polyimide varnish (U-Varnish S manufactured by Ube Industries, Ltd.) was coated, and the temperature was 210 ° C.
Then, it was dried and hardened in a warm air circulation furnace for 1 hour, and a polyimide resin layer having a thickness of 15 μm was laminated as a sliding layer 4.

Then, the fixing belt thus prepared is subjected to image heating fixing 100 of the electromagnetic induction heating system as shown in FIG.
It was attached and subjected to an idle rotation durability test. The results are shown in Table 2.

(Dry rotation endurance test) While controlling the temperature to 220 ° C., the pressure roller was pressed against the fixing belt with a predetermined pressure, and the fixing belt was rotated by the pressure roller. As the pressure roller, a rubber roller having an outer diameter of 30 mm in which a silicone layer having a thickness of 3 mm was coated with a PFA tube having a thickness of 30 μm was used. In this experimental example, the pressing force is 200 N and the fixing nip is 8 mm ×
230 mm, the surface speed of the fixing belt is 100 mm
/ Sec is set. Each of the fixing belts was subjected to the above rotation test, and the time until occurrence of cracking / breaking of the belt was defined as the durability time.

[0108]

[Table 2]

When the fixing belt of the present invention having a crystal orientation ratio I ₍₂₀₀₎ / I ₍₁₁₁₎ of 3 or more and a micro Vickers hardness of 280 to 450 was used, the endurance time exceeded 300 hours in all cases. Of these, the crystal orientation ratio I ₍₂₀₀₎ / I
₍₁₁₁₎ is 8 or more, Micro Vickers hardness is 330-4
No. 20 fixing belt of the present invention has a durability time of 40
It's been over 0 hours. On the other hand, the crystal orientation ratio I ₍₂₀₀₎ / I
_When the fixing belt of Comparative Example having ₍₁₁₁₎ of less than 3 was used, none of the durability times exceeded 200 hours. The crystal orientation ratio I ₍₂₀₀₎ / I ₍₁₁₁₎ is 8 or more, and the sulfur content is 0.0.
With respect to the fixing belt of the present invention, the content ratio of manganese to the content of sulfur (mass ratio) is 3 to 10 and the content ratio of cobalt to the content of sulfur (mass ratio) is 1 or less. It was confirmed that each of them had durability exceeding 600 hours.

[Experimental Example 2] Further, the fixing device used in Experimental Example 1 was replaced with a full color LBP LASER manufactured by Canon.
It was mounted on SHOT "LBP-2040", imaged and subjected to a durability test. Pressing force is 200N, fixing nip is 8m
The fixing temperature was 200 ° C. and the process speed was 100 mm / sec. [Example 1]
In the case of using the fixing belt of [Example 8], 100,000 sheets were printed without trouble and the durability test was completed. Further, with the fixing belts of [Example 9] to [Example 10], 70,000 sheets were printed without trouble, and the durability test was completed. On the other hand, the case using the fixing belt of [Comparative Example 1] is 1
The number of sheets using the fixing belt of [Comparative Example 2] was 30,000, and the sheet was not able to pass due to the destruction of the fixing belt.

[Experimental Example 3] The fixing belt of the present invention was attached to a belt heating type apparatus (fixing apparatus 100) using a ceramic heater as a heating body as shown in FIG. 7, and subjected to an idle rotation durability test. It was possible to confirm sufficient heat resistance and durability.

[0112]

According to the present invention, in an image heating apparatus capable of low energy heating by utilizing a heating body having a small heat capacity, a fixing belt excellent in durability, particularly at high temperature,
Further, it is possible to provide a highly durable and highly reliable image heating device.

[Brief description of drawings]

FIG. 1 is an example of a layer configuration model diagram of a fixing belt of the present invention.

FIG. 2 is an example of a layer configuration model of the fixing belt of the present invention.

FIG. 3 is a diagram showing the relationship between the depth of a heat generating layer and the intensity of electromagnetic waves.

FIG. 4 is a schematic configuration diagram of an image heating apparatus used in the first embodiment.

FIG. 5 is a model diagram of a magnetic field generating means of the image heating apparatus used in the first embodiment.

FIG. 6 is a diagram showing the relationship between the magnetic field generating means of the image heating apparatus used in the first embodiment and the amount of heat generation Q.

FIG. 7 is a schematic configuration diagram of an image heating apparatus used in a second embodiment example.

FIG. 8 is a schematic configuration diagram of an image heating apparatus used in another embodiment.

[Explanation of symbols]

1, 1'Heating layer (metal layer) 2 Elastic layer 3, 3'Releasing layer 4, 4'Sliding layer 10, 10 'Fixing belt 12 Ceramic heater 16 Belt guide 17 Magnetic core 18 Exciting coil 19 Insulating member 22 Addition Rigid stays for pressure 23a, 23b Flange member for regulating / holding the end portion of the fixing belt 26 Temperature detecting element (thermistor) 27 Exciting circuit 30 Pressurizing member (pressurizing roller) 31 Drive roller 32 Tension roller 40 Sliding plate N Fixing nip portion t toner image P recording material C magnetic flux 100 image heating fixing device

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuo Kishino 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Hideyuki Yano 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. Incorporated (72) Inventor Masahiro Suzuki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) Reference JP 2002-148975 (JP, A) JP 2002-206188 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 13/20 G03G 15/20 C25D 1/02-1/04

Claims (12)

(57) [Claims] 1. A fixing belt having at least a release layer and a nickel electroformed metal layer, wherein the nickel electroformed has a crystal orientation ratio I (200) / I (111) of 8 or more.
A fixing belt having a crystal orientation of (200) plane preferential growth . Wherein electroforming the nickel electroforming is fixing belt according to claim 1, microswitch Vickers hardness, characterized in that it is 280-450. 3. The nickel electroformed sulfur content is:
The fixing according to claim 1, wherein the content of the carbon element in the nickel electroforming is 0.03 mass% or less, is 2 mass times or more the sulfur content, and is 0.08 mass% or less. belt. 4. The nickel electroformed sulfur content is:
The fixing belt according to claim 3, wherein the fixing belt content is 0.0001% by mass or more. 5. The nickel electroformed sulfur content is:
The fixing belt according to claim 3, wherein the fixing belt has a content of 0.001% by mass or more. 6. The fixing belt according to claim 3, wherein the nickel electroformed manganese content is 0.2 to 10 times the sulfur content by mass. 7. The content of cobalt in the nickel electroforming is 0.1 to 5 times the content of sulfur by mass.
The fixing belt described in. 8. The fixing belt according to claim 1, further comprising an elastic layer between the release layer and the metal layer. 9. The fixing belt according to claim 8, wherein the elastic layer is made of silicone rubber, fluororubber or fluorosilicone rubber. 10. A fixing belt, and a pair of pressure contact members that are in pressure contact with each other via the fixing belt, wherein an inner surface of the fixing belt slides with one of the pressure contact members and is heated by heat from the fixing belt. An image heating fixing device for heating and fixing an image on a recording material, wherein the fixing belt is the fixing belt according to any one of claims 1 to 9. 11. A magnetic flux generating means for generating a magnetic flux,
2. The fixing belt generates heat due to the magnetic flux generated by the magnetic flux generating means to heat and fix the image on the recording material.
The image heating and fixing device according to item 0. 12. The image heating according to claim 11, wherein the pressure contact member that slides on the fixing belt is a heating body, and the image on the recording material is heated and fixed by heat from the heating body via the fixing belt. Fixing device.