JP2000187407A - Heating unit, image forming device using same and dielectric heating member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently conduct heat to a body to be heated and to improve the fixability of an image on the body to be heated without causing exuding by dispersing high heat conductive particles in the elastic layer of the heat resistant film of a heating unit. SOLUTION: The heating unit has a heat resistant film 1 with a two-layered structure consisting of a base layer 1-1 and an elastic layer 1-2 based on a heat resistant resin such as polyimide resin, polyether sulfone resin, polyether ketone resin, polyether imide resin, polyamide imide resin, silicone resin or fluororesin and containing dispersed high heat conductive particles such as ceramic, metal oxide or metal particles, e.g. particles of SiC, Si3N4, BN, AlN, Al2O3, Ni, Fe or Al having such a high heat conductivity as >=0.04 cal/cm.sec. deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating device for applying heat energy to a member to be heated such as a recording material sheet, an image forming apparatus using the device as a fixing means, and a dielectric heating member.

[0002]

2. Description of the Related Art Conventionally, a heat roller system has been used as a fixing device of an image output apparatus such as a copying machine, a printer, a facsimile, etc., using an electrophotographic technique. This method is based on a metal roller having a heater inside, and a pressure roller having elasticity pressed against the roller, and the recording material is passed through a fixing nip formed by the pair of rollers. This is to fix the toner image on the recording material by heating and pressing. However, in such a heat roller system, since the heat capacity of the roller is large, it takes much time to raise the roller surface temperature to the fixing temperature. In addition, in order to quickly execute the image output operation, there is a problem that the roller surface must be adjusted to a certain temperature even when the apparatus is not used.

Therefore, as fixing methods devised to solve these problems, Japanese Patent Application Laid-Open No. 63-313182 and Japanese Patent Application Laid-Open No.
There is a method and apparatus disclosed in Japanese Patent No. 157878. Apparatus using this method is usually a thin heat-resistant film, a heater fixedly disposed on one side of the film, and disposed on the other side of the film to face the heater. And a pressurizing member for bringing the recording material to be image-fixed into close contact with the heater via the film (film heating type fixing device).

In the fixing operation of such a film heating type fixing device, the recording material is passed through a fixing nip formed by pressing a heater and a pressing member with the film interposed therebetween, so that a visible image of the recording material is obtained. This is performed by heating the surface of the carrier with a heater through a film, applying thermal energy to the unfixed image, and softening and melting the toner.
The fixing film of such a film heating type fixing device has a release layer of PTFE or PFA having a thickness of 5 to 20 μm on an outer surface of a heat-resistant resin (for example, PI: polyimide) having a thickness of 20 to 50 μm. Is used.

[0005] In such a film heating type fixing device, a heater having a low heat capacity can be used, so that the weight time can be shortened (quick start) as compared with the conventional heat roller type. In addition, since the quick start can be performed, preheating during non-printing operation is not required, and power saving in a comprehensive sense can be achieved.

[0006]

However, when fixing is performed using a fixing film having such a configuration, image displacement and bleeding may occur. In particular, when fixing a plurality of superposed toners of different colors, the toner layer is thick, so that the image blurs around the original image with the colors of the individual toners.

In order to solve this problem, the present applicant has proposed a device in which an elastic layer is provided on a film surface (Japanese Patent Laid-Open No. 10-46868). In this proposal, by wrapping the toner image by deformation of the elastic layer, image displacement and bleeding can be prevented, but on the other hand, the thickness of the entire film of the proposed device is increased, and the fixing property is poor. There was a disadvantage of becoming. In addition, there is a problem that an offset due to charging of the film is easily generated. This is because the thickness of the entire film increases due to the presence of the elastic layer, and the capacitance decreases. Therefore, it is considered that the surface potential is increased even if the surface charge amount is the same.

An object of the present invention is to provide a heating apparatus, an image forming apparatus, and a dielectric heating member which are free from image deviation and image bleeding and have no defective fixing. Is its purpose.

It is another object of the present invention to provide a heating device, an image forming apparatus, and a dielectric heating member that do not cause a fixing defect and do not generate an offset.

[0010]

SUMMARY OF THE INVENTION The present invention comprises a heating element and a heat-resistant film having one surface in contact with and sliding on the heating element and the other surface in contact with the object to be heated. In a heating device that heats the object to be heated by moving together with the object to be heated, the heat-resistant film has at least a base layer and an elastic layer. The conductivity is 0.04 cal / cm. sec. A heating device characterized by containing a filler having a temperature of not less than ° C.

Further, the present invention heats the object to be heated by passing the object to be heated through a nip in which a heating member comprising an exciting coil and an induction heating member and a pressure member are pressed against each other. In the heating device, the induction heating member is:
It has a heat generating layer containing at least a magnetic metal and an elastic layer, and has a thermal conductivity of 0.04 cal / cm. sec. ° C
A heating device comprising the filler described above.

Further, the present invention is an image forming apparatus characterized by using these heating devices as fixing means.

According to the present invention, by dispersing the high thermal conductive particles in the elastic layer of the heat-resistant film of the heating device, heat can be efficiently transmitted to the object to be heated without blurring or bleeding of the image at the time of fixing. Thus, the fixing property of the image on the object to be heated can be improved.

Further, by dispersing conductive high thermal conductive particles as a filler, or by dispersing a conductive filler together with the high thermal conductive particles, the electric resistance of the elastic layer is reduced, and the charge on the elastic layer surface is reduced. The prevention or the low-resistance elastic layer increases the capacitance of the entire heat-resistant film. As a result, the surface potential due to the charge on the surface of the heat-resistant film is reduced, and electrostatic offset of the image on the object to be heated to the surface of the elastic layer can be prevented.

In the heating device of the present invention, the content of the filler in the elastic layer can be reduced by using a filler having a high thermal conductivity, as will be described in Examples described later. Since the heat conduction of the elastic layer can be increased by the filler, a preferable upper limit of the content is 50% by weight. On the other hand, if the content of the filler in the elastic layer is too small, the excellent effects of the present invention cannot be achieved, so the preferable lower limit of this content is 5% by weight. Preferably, the filler is dispersed as uniformly as possible in the elastic layer. Hereinafter, the present invention will be described more specifically with reference to the drawings.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic sectional view for explaining the structure of a main part of an image forming apparatus using a heating device according to the present invention as a fixing device.

In FIG. 1, reference numeral 501 denotes a photosensitive drum, on which a photosensitive material such as OPC, amorphous Se, amorphous Si or the like is formed on a cylindrical base such as aluminum or nickel. The photosensitive drum 501 is driven to rotate in the direction of the arrow, and its surface is first uniformly charged by a charging roller 502 as a charging device. Next, the laser beam 5 that is ON / OFF controlled according to the image information
03, and an electrostatic latent image is formed on the surface. This electrostatic latent image is developed and visualized by the developing device 504. As the developing method, a jumping developing method,
Two-component developing method, FEED developing method (Floating E
Electrode Effect Pevelopme
nt) and the like, and are often used in combination with image exposure and reversal development.

The visualized toner image is transferred from the surface of the photosensitive drum 501 onto the transfer material P conveyed at a predetermined timing by a transfer roller 505 as a transfer device. At this time, the transfer material P is conveyed while being held between the photosensitive drum 501 and the transfer roller 505 with a constant pressing force. The transfer material P to which the toner image has been transferred is transported to the fixing device 506, where it is fixed as a permanent image. On the other hand, the transfer residual toner remaining on the photosensitive drum 501 is removed from the surface of the photosensitive drum 501 by the cleaning device 507.

FIG. 2 is a sectional view showing details of the structure of the fixing device 506.

In FIG. 2, reference numeral 9 denotes a heating element, which has a good heat conductive substrate 8 and a resistance layer 7 which generates heat when energized, and has an insulating glass coat 1 having a thickness of about 10 μm on the film sliding surface.
0 is given. 11 is a thermistor, 12 is a heater support for insulatingly supporting the heater, 14 is a heat-resistant film 1
, A driven roller, 16 a pressure roller, P a recording material, and T a toner, and arrows in the figure indicate the respective rotating directions and conveying directions.

FIG. 3 is a sectional view showing details of another configuration of the fixing device 506.

In the apparatus shown in FIG. 3, the heat-resistant film 1 is loosely inserted so that tension is not applied to the stay 13, and the film driving roller is connected to the pressing roller
Is also configured.

Next, the structure of the heat-resistant film 1 is shown in FIG. 4 as a sectional view, and will be described in detail below.

In FIG. 4, the heat-resistant film 1 has a two-layer structure including a base layer 1-1 and an elastic layer 1-2.
1 is a heat-resistant resin such as a polyimide resin, a polyether sulfone resin, a polyether ketone resin,
Polyether imide resin, polyamide imide resin, silicone resin, fluorine resin and the like are used.

Based on this, high thermal conductive particles 18 such as ceramic powder, metal oxide powder and metal powder are dispersed.
Specifically, silicon carbide (SiC) / silicon nitride (Si
₃ N ₄₎ · boron nitride (BN) · aluminum nitride (Al
N), alumina (Al ₂ O ₃ ), nickel, iron, aluminum and other particles having high thermal conductivity. All of these particles have a thermal conductivity of 0.04 cal / cm. sec. ° C or higher.

The number average particle diameter of the high thermal conductive particles is 0.1-20.
μm is suitable, and the content in the base layer 1-1 is 0.5 to 8
wt% is preferred. This is because when these filler particles are dispersed in a heat-resistant resin, the effect of increasing thermal conductivity is obtained without impairing the film strength, and the filler particles can be easily dispersed. This is because the effect can be obtained even if the amount of the high thermal conductivity particles mixed into the film is small.If too much of these fillers are mixed, the flexibility of the film is lost, and the film bending degree decreases. It will be damaged.

Further, during the film formation, irregularities were not generated on the inner surface of the base layer due to the dispersion of the powder. As the surface shape, those having a surface roughness Rz of 10 μm or less are preferable. In order to smooth the film surface on the heater contact side, reduce the friction between the film and the heater on the heater surface, and not reduce the performance even for long-term use, the surface shape should be less than the above surface roughness. Is good.

Further, the above-mentioned filler includes AC of a heater.
In order to prevent leakage from the heater surface when an overvoltage is applied to the bias, it is preferable to use a material having a high volume resistance value, preferably a material having a value of 10 ⁴ Ωcm or more. When a filler having a lower volume resistance value is used, the base film cannot be provided with insulating properties, so that it is necessary to reduce the amount of filler dispersion or increase the thickness of the glass coat on the heater surface.

In the present embodiment, fluororesin particles 20 such as PFA, PTFE, FEP, etc.
The highly thermally conductive particles 19 such as ceramic powder, metal oxide powder, and metal powder are dispersed on the basis of this. Specifically, silicon carbide (SiC), silicon nitride (Si ₃ N ₄ ), boron nitride (BN), aluminum nitride (AlN), alumina (Al ₂ O ₃ ), Ni
It is a particle having high thermal conductivity such as Al. All of these particles have a thermal conductivity of 0.04 cal / cm. sec. The average particle size is 0.1 to 20 μm or less, and the content in the elastic layer is preferably 5 to 50% by weight.

By using a filler having a high thermal conductivity, the heat conductivity of the elastic layer can be increased by adding a small amount of the filler, and the fixing property can be improved. For this reason, the hardness of the elastic layer can be kept low, and the elastic layer is easily deformed, so that it is easy to cover the unfixed toner image and suppress image shift and bleeding.

Conversely, if a filler having a low thermal conductivity is used, it is necessary to increase the amount of dispersion in the elastic layer, the hardness of the elastic layer is increased, and the elastic layer is not easily deformed, so that image displacement and bleeding are liable to occur. In this regard, the rubber hardness of the elastic layer is preferably 30 ° or less (JIS A) (JIS K6301).

Table 1 shows the thermal conductivity of each material.

The thermal conductivity is a value measured by the hot wire method as follows.

The measurement sample is a bulk of a sintered body of a high heat conductive material before being used as a filler, which is 100 mm × 50 mm × 20 mm.
mm. As a measuring instrument, a thermal conductivity measuring instrument (trade name: QTM-500, manufactured by Kyoto Electronics Industry, using "PD11" as a probe) is used. The current value to the heating wire is set in the automatic selection mode, and the measurement environment is room temperature.

[0035]

[Table 1]

According to the experiment conducted by the inventor, the configuration shown in FIG.
In the case where SiO ₂ is used as the heat transfer filler of the elastic layer 1-2 and the case where BN is used, in order to obtain the same fixability, BN needs to be added in an amount of 1/4 or less of SiO ₂ .

[0037]

EXAMPLES (Example 1) A heat-resistant film having an inner diameter of 24 mm shown in FIG. 4 was manufactured as follows.

(Base layer 1-1) Polyimide varnish (trade name: polyimide U-varnish-S, manufactured by Ube Industries) 360
g and a polyimide varnish (trade name: polyimide U-varnish-A, manufactured by Ube Industries, Ltd.), and BN (boron nitride, average particle size 1.5 μm) (trade name: UHP-S)
1, Showa Denko), after curing the varnish, BN
Then, the mixture was added to an amount of t%, followed by sufficient stirring.

In the varnish thus prepared, an outer diameter of 2
A 4 mm cylindrical mold was dipped, pulled up, and a varnish was applied to the surface of the cylindrical mold.

Next, at 120 ° C. for 40 minutes and at 200 ° C. for 20 minutes.
, 40 minutes at 220 ° C and 50 minutes at 400 ° C to complete the imide conversion reaction. After the heat treatment, the resultant was cooled to room temperature, and the formed polyimide film was separated from the cylindrical mold to produce a base layer having a thickness of 50 μm.

(Elastic Layer 1-2) Latex liquid of fluororubber (vinylidene fluoride-hexafluoropropene-tetrafluoroethylene terpolymer) (trade name: DYEL latex GL-152A, manufactured by Daikin Industries, fluororubber) 82.7 parts of a fluororesin dispersion liquid (trade name: Dispersion AD-1, manufactured by Daikin Industries, PFA content: 52% by weight) was mixed with 100 parts (weight) of a concentration of 43% by weight. BN particles (trade name: UHP-S)
1) was added to a dry weight ratio of 10% by weight, and sufficiently stirred to obtain a liquid A.

A mixture 30 obtained by mixing 4 parts of a silane coupling agent with 1 part of a polyamine vulcanizing agent (trade name: Epomate F-100, manufactured by Yuka Shell).
Was dissolved in 70 parts of water to obtain a solution B.

Next, the liquid A and the liquid B were mixed at a ratio of 15 parts of the liquid B to 100 parts of the fluororubber in the liquid A. The mixture is spray-coated on the base layer,
Baked at 330 ° C. for 60 minutes to obtain 100% containing fluorine resin 50 wt% and BN particles 10 wt%.
A fluorine rubber elastic layer having a thickness of μm was formed.

During the sintering step, a part of the fluororesin precipitates on the surface of the elastic layer and dissolves by about 1 μm.
An m-thick fluororesin film is formed.

A heat-fixing apparatus using the heat-resistant film manufactured as described above as the heat-resistant film shown in FIG. 3 was used in a color laser printer (trade name: LBP-203).
(Manufactured by Canon Inc.) as a fixing device. Fixing device process speed is 30mm / sec
c, The temperature of the heating element is 190 ° C., the total pressure by the pressure roller is 12 kg, the outer diameter of the pressure roller is 20 mm, and the surface rubber hardness of the pressure roller is 48 ° (ASKER-C).

The print output is 7 at a resolution of 600 dpi.
As a horizontal line image of dots, a horizontal line was printed by superposing three color toners of yellow toner, magenta toner and cyan toner at the same dot position.

In the fixed horizontal line image, there was no blur, and no color blur was observed at the outline of the horizontal line image.
No toner adhesion was observed on the surface of the heat-resistant film of the fixing device after the first print output.

In this embodiment, A is used instead of BN particles.
Similar results were obtained for heat-resistant films manufactured using particles of l ₂ O ₃ , SiC, Si ₃ N ₄ and AlN (average particle size: 1.5 μm).

Comparative Example 1 In Example 1, SiO ₂ particles (average particle diameter of 1.2 μm) were used instead of the BN particles in the elastic layer.
m) and a heat-resistant film manufactured using TiO ₂ particles (average particle size: 2.0 μm) was printed out in the same manner as in Example 1, and TiO ₂ was also used for those using SiO _2. Also for the used one, the fixing of the horizontal line image was not sufficiently performed, and the toner was peeled off by finger touch.

When the content of SiO ₂ and TiO _{2 in} the fluororubber elastic layer was set at 40 wt%, the fixability was improved, but color bleeding occurred at the outline of the horizontal image.

Embodiment 2 The structure of the heat-resistant film 30 employed in this embodiment is shown in a sectional view of FIG. 5, and will be described below. In this embodiment, an elastic layer 31 (see FIG. 5) is used. As in the case of the elastic layers 1-2 in FIG. 4, the fluororesin particles 20 and the high heat conductive particles 19 are dispersed in the layer.
By adding 2, it was possible to prevent charging of the film and prevent image defects due to electrostatic offset.

The conductive filler preferably has a volume resistivity of 500 Ω · cm or less. The volume specific resistance of the conductive filler is determined by measuring a cylinder (inner diameter 25 mm, length 1
00 mm) and under a pressure of 100 kg / cm ² ,
It is the value measured between the top and bottom electrodes of the cylinder at a voltage of 100V.

(Embodiment 3) As shown in Embodiment 2 above,
By adding a conductive filler 32 such as carbon to the elastic layer 31 as shown in FIG. 5, charging of the film can be prevented and image defects due to electrostatic offset can be prevented. If you put
To lower the resistance, it is necessary to add a large amount of carbon, and the hardness of the elastic layer increases, so that the resistance of the elastic layer cannot be reduced much. Therefore, in this embodiment, K ₂ O · nTiO is used as the conductive filler 32 in FIG.
₂ (potassium _{titanate), 9Al 2 O 3 · 2B} 2 O 3 ( aluminum borate), Si ₃ N _4, and whiskers such as SiC, conductive such as by metal deposited on the surface of the alumina short fibers or short glass fibers The material used was a metal whisker, graphite short fiber, or the like. When these conductive fillers were added, the resistance of the elastic layer could be reduced with a small amount, the charge of the film was prevented, and the image defect due to the electrostatic offset was prevented. Also, since the hardness of the elastic layer is low,
No image shift or bleeding occurred.

The whiskers and short fibers having a thickness of 15 μm or less and a length of 5 to 1000 μm were used in this embodiment.

(Embodiment 4) In FIG. 4, in Embodiment 1, PFA, PTFE, F
A dispersion of fluororesin particles 20 such as EP is used, and silicon carbide (SiC) / silicon nitride (S
i ₃ N ₄ ), boron nitride (BN), aluminum nitride (A
1N), alumina (Al ₂ O ₃ ), Ni, Fe, Al and the like, and high thermal conductive particles 19 are dispersed.
The high thermal conductive particle filler used in Example 1 was made conductive by depositing a metal on the surface. As a result, the resistance of the elastic layer could be reduced without adding a filler other than the high thermal conductive filler. For this reason, the total amount of filler could be suppressed, and the hardness of the elastic layer could be reduced.

(Embodiment 5) The structure of the heat-resistant film 40 employed in this embodiment is shown in FIG. 6 as a cross-sectional view. This will be described below. In this embodiment, as shown in FIG. It is composed of four layers.

For the base layer 41, a PI resin in which the high thermal conductive particles 18 were dispersed was used. The thickness of the base layer 41 is 30 to 10
0 μm.

On the base layer 41, a conductive primer layer 42
And grounded by means not shown. The thickness of this layer 42 is 10 μm or less.

The next elastic layer 43 is made of fluorine rubber or Si.
A material obtained by dispersing conductive high heat conductive particles 45 in rubber was used. The thickness of the elastic layer 43 is 30 μm or more and 500 μm.
It is as follows.

The next surface layer 44 is made of PFA, PTFE, FE
It is made of fluororesin such as P and has a thickness of 1 μm to 50 μm
In the following, a small amount of conductive filler such as carbon is added.

In the present embodiment, the triboelectric charge generated on the film surface escapes in the following path: surface layer → elastic layer → conductive primer layer → earth. Thanks to the conductive primer layer, the distance over which charges move in the elastic body can be short, and offset is difficult.

Since the surface charge of the surface layer 44 escapes into the elastic layer to some extent due to pinholes or the like, it is not always necessary to add a conductive filler.

In the case where a voltage having a polarity opposite to that of the toner is positively applied to the conductive primer layer 42 to prevent offset, or when the conductive primer layer is grounded using a rectifying element such as a diode, It is not necessary to put a conductive filler in layer 44 to release surface charge. However, the lower the resistance of the elastic layer is, the stronger the electric field between the nips can be.

(Embodiment 6) FIG. 7 is a schematic sectional view showing the structure of a heat fixing device 200 according to the present invention.

The fixing film 20 which is a heating member
Reference numeral 1 denotes a stay 202 loosely fitted to a stay 202 made of a liquid crystal polymer, a phenol resin, or the like.

The pressure roll 205 comprises an elastic layer 207 formed by foaming heat-resistant rubber such as silicon rubber or fluorine rubber or silicon rubber on the outside of a cored bar 206, on which PFA, PTFE, FEP or the like is formed. A release layer may be formed. The pressure roll 205 is rotationally driven in a direction indicated by an arrow by a rotational drive (not shown) from a longitudinal end portion via a metal core 206. Thus, the fixing film 2
01 is driven to rotate outside the stay 202.

Numeral 203 denotes an excitation coil, which has a conductor 203b wound around a core material 203a made of a ferromagnetic material such as ferrite, and the oscillation circuit is energized from a longitudinal end thereof by a power source whose frequency is variable. In this embodiment, a U-shape is used as the excitation coil core material 203a to form a closed magnetic circuit.

The AC power supply 204 is a high frequency AC current of 10 kHz to 1 MHz, preferably 20 kHz to 800 kHz.
Is applied to the exciting coil 203 to generate an alternating magnetic field.

FIG. 8 is a cross-sectional view showing the structure of the fixing film 201 employed in this embodiment. As shown in FIG. 8, the fixing film 201 has a two-layer structure.
e, a base layer 201a made of a magnetic metal such as Ni and having a thickness of about 10 to 150 μm.

An eddy current flows in the base layer 201a due to the alternating magnetic field generated by the excitation coil 203, generating Joule heat, and heat-fixing the toner image on the transfer material conveyed to the fixing nip.

The temperature of the fixing film 201 is detected by a temperature detecting means (not shown).
Sent to the CPU via the / D converter, and based on this,
The PU adjusts the amount of heat generated in the fixing film 201 by changing the magnetic field intensity generated from the exciting coil 203 by changing the frequency of the AC power supply 204, and controls the temperature of the fixing film 201 to a predetermined value.

In the fixing film 201, the base layer 201
There is an elastic layer 201b on a.

In this embodiment, fluororesin particles 2 such as PFA, PTFE, FEP, etc.
The high thermal conductive particles 19 such as a ceramic powder, a metal oxide powder, and a metal powder are dispersed on the base. Specifically, silicon carbide (SiC), silicon nitride (Si ₃ N ₄ ), boron nitride (BN), aluminum nitride (AlN), alumina (Al ₂ O ₃ ), Ni, Fe
-High thermal conductivity particles such as Al. All of these particles have a thermal conductivity of 0.04 cal / cm. sec. Over ℃,
The average particle size was 20 μm or less, and the mixing ratio to the elastic layer was 50 wt% or less.

By using a filler having a high thermal conductivity, the heat conductivity of the elastic layer can be increased with a small amount of addition, and the fixing property can be improved. For this reason, the hardness of the elastic layer can be kept low, and the elastic layer is easily deformed, so that it is easy to cover the unfixed toner image and suppress image shift and bleeding.

Conversely, if a filler having a low thermal conductivity is used, it is necessary to increase the amount of dispersion in the elastic layer, and the elastic layer becomes harder and less susceptible to deformation, so that image shift and bleeding are likely to occur.

(Embodiment 7) FIG. 9 is a sectional view showing the structure of the heat-resistant film 301 employed in this embodiment.
This will be described below. In this embodiment, as shown in FIG. 9, the heat-resistant film 301 has three layers.

The base layer 301a is made of Fe, Ni, etc.
This layer is a metal film of about 150 μm, and this layer is grounded by means not shown. On the base layer 301a, there is provided an elastic layer 301b having a thickness of 30 to 500 μm and made of a material obtained by dispersing conductive high heat conductive particles 45 in fluoro rubber or Si rubber.

The upper surface layer 301c has a thickness of 1 to 50 μm.
m of a fluororesin such as PFA, PTFE, and FEP. The surface layer 301c may contain a small amount of conductive filler.

In the present embodiment, the triboelectric charge generated on the film surface escapes through the route of surface layer → elastic layer → base layer → earth. Thanks to the base layer, which is a conductive layer, the distance over which charges move in the elastic body can be short, and offset is difficult.

The surface charge of the surface layer 301c escapes into the elastic layer to some extent due to pinholes or the like, so that it is not always necessary to add a conductive filler.

In addition, when the offset is prevented by positively applying a voltage having the opposite polarity to the toner to the base layer, or when the base layer is grounded by using a rectifying element such as a diode,
It is not necessary to put a conductive filler in the surface layer 301c to release surface charges.

Hereinafter, a production example of the heat-resistant film of this embodiment will be described.

(Base layer 301a) 3 prepared by electroforming
Endless Ni film with a diameter of 0 mm and a thickness of 15 μm.

(Elastic Layer 301b) Latex liquid of fluororubber (vinylidene fluoride-hexafluoropropene-tetrafluoroethylene terpolymer) (trade name: Daiel Latex GL-152A, manufactured by Daikin Industries, fluorine rubber concentration 43 wt. %) And 8.3 parts of a fluororesin dispersion (trade name: Dispersion AD-1, manufactured by Daikin Industries, PFA content: 52 wt%) were mixed with 100 parts (weight). BN particles (trade name: UHP-S)
1) was added to a dry weight ratio of 10% by weight, and sufficiently stirred to obtain a liquid A.

Further, a mixture 30 obtained by mixing 4 parts of a silane coupling agent with 1 part of a polyamine vulcanizing agent (trade name: Epomate F-100, manufactured by Yuka Shell).
Was dissolved in 70 parts of water to obtain a solution B.

Next, the liquid A and the liquid B were mixed at a ratio of 15 parts of the liquid B to 100 parts of the fluororubber in the liquid A. The mixture is spray-coated on the base layer,
After pre-drying at 300 ° C., baking is performed at 330 ° C. for 60 minutes.
An m-thick fluororubber elastic layer was formed.

(Surface layer 301c) A fluororesin dispersion (trade name: Dispersion AD-1) is spray-coated on the surface of the elastic layer, preliminarily dried at 80 to 100 ° C, baked at 330 ° C for 30 minutes, and baked at 10 µm. A thick fluororesin surface layer was formed.

A heat fixing apparatus using the heat-resistant film thus manufactured as a fixing film shown in FIG. 7 was used as a color laser printer (trade name: LBP-203).
(Manufactured by Canon Inc.) as a fixing device. The fixing device process speed is 60mm / sec
c, the temperature of the base layer side of the fixing film is 150 ° C., the total pressing force by the pressing roller is 30 kg, and the outer diameter of the pressing roller is 30 m.
m and the surface rubber hardness of the pressure roller are 45 ° (ASKE
RC).

The print output is 7 dpi at a resolution of 600 dpi.
As a horizontal line image of dots, a horizontal line was printed by superimposing three color toners of yellow toner, magenta toner and cyan toner.

The fixed horizontal line image had no blur, and no color blur was observed at the outline of the horizontal line image.
Further, no toner adhesion was observed on the surface of the heat-resistant film of the fixing device.

In this example, A was used instead of BN particles.
Similar results were obtained for heat-resistant films manufactured using particles of l ₂ O ₃ , SiC, Si ₃ N ₄ and AlN.

Comparative Example 2 In Example 7, SiO ₂ particles (average particle size: 1.2 μm) and T
When the print output was performed in the same manner as in Example 1 using a heat-resistant film manufactured using iO ₂ particles (average particle size: 2.0 μm), those using SiO ₂ also used TiO ₂ Also, the fixing of the horizontal line image was not sufficiently performed, and the toner was peeled off by finger touch.

When the content of SiO ₂ and TiO _{2 in} the fluororubber elastic layer was 40% by weight, the fixability was improved, but color bleeding occurred at the outline of the horizontal image.

[0094]

As described above, according to the present invention,
By dispersing the high thermal conductive particles in the elastic layer of the heat-resistant film of the heating device, the heat can be efficiently transmitted to the object to be heated without causing blurring and blurring of the image at the time of fixing. It can improve the fixability of the image.

Further, by dispersing conductive high thermal conductive particles as a filler, or by dispersing a conductive filler together with the high thermal conductive particles, the electric resistance of the elastic layer is reduced and the charge on the surface of the elastic layer is reduced. This can prevent electrostatic offset to the surface of the elastic layer of the image on the object to be heated.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view illustrating a configuration of a main part of an image forming apparatus using a heating device according to the present invention as a fixing device.

FIG. 2 is a cross-sectional view illustrating a configuration of a heat fixing device according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing the configuration of another embodiment of the heat fixing device of the present invention.

FIG. 4 is a cross-sectional view illustrating a configuration of a fixing film according to an embodiment of the present invention.

FIG. 5 is a cross-sectional view showing the configuration of another example of the fixing film according to the embodiment of the present invention.

FIG. 6 is a cross-sectional view illustrating a configuration of still another example of a fixing film according to an embodiment of the present invention.

FIG. 7 is a schematic sectional view showing a configuration of an embodiment of a heat fixing device according to the present invention.

8 is a cross-sectional view showing a configuration of a certain fixing film used in the embodiment of the heat fixing device of the present invention shown in FIG.

FIG. 9 is a cross-sectional view showing the configuration of another fixing film used in the embodiment of the heat fixing device of the present invention shown in FIG.

Claims (18)

[Claims] 1. A heating element and a heat-resistant film having one surface in contact with and sliding on the heating element and the other surface in contact with the object to be heated. In a heating device that heats the object to be heated by moving as
The heat-resistant film has at least a base layer and an elastic layer, and has a thermal conductivity of 0.04 cal / cm. sec.
A heating device characterized by containing a filler having a temperature of at least ° C. 2. The filler content in the elastic layer is from 5 to 50.
2. The heating device according to claim 1, wherein the heating device is in a weight%. 3. The heating device according to claim 1, wherein the filler is a particle selected from the group consisting of a ceramic powder, a metal oxide powder, and a metal powder. 4. The method according to claim 1, wherein the filler is silicon carbide, silicon nitride,
Boron nitride, aluminum nitride, alumina, Ni, Fe
And particles selected from the group consisting of Al and Al.
A heating device as described. 5. The heating device according to claim 1, wherein a conductive filler is contained in the elastic layer. 6. The heating device according to claim 1, wherein the elastic layer contains fluororesin particles. 7. The heating device according to claim 1, wherein a surface layer is formed on the elastic layer. 8. The heating device according to claim 7, wherein the surface layer is a fluororesin layer. 9. The heating device according to claim 1, wherein a filler is dispersed in the fluororubber. 10. The elastic layer has a thickness of 30 μm to 500 μm.
The heating device according to claim 1, wherein 11. A heating device for heating an object to be heated by passing the object to be heated through a nip where a heating member comprising an exciting coil and an induction heating member and a pressing member are pressed against each other. The induction heating member has at least a heat generating layer having a magnetic metal and an elastic layer, and the elastic layer has a thermal conductivity of 0.04 cal / cm. sec. A heating device characterized by containing a filler having a temperature of at least ° C. 12. The filler content in the elastic layer is 5-5.
The heating device according to claim 11, which is 0% by weight. 13. The elastic layer has a thickness of 30 μm to 500 μm.
The heating device according to claim 11, which is: 14. The heating device according to claim 11, further comprising a fluororesin layer on the elastic layer. 15. An image forming apparatus using the heating device according to claim 1 as a fixing unit. 16. A heat generating layer having at least a magnetic metal and an elastic layer, wherein the elastic layer has a heat conductivity of 0.04 c
al / cm. sec. An induction heating member characterized by containing a filler having a temperature of not less than ° C. 17. The induction heating member according to claim 16, wherein the filler is dispersed in the fluororubber layer. 18. An induction heating member having a fluororesin layer on the surface of an elastic layer.