JPH0782272B2 - Fixing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention is used for fixing or drying used in an image forming apparatus such as a copying machine, a printing machine, a facsimile machine, a printer, or a composite machine of these. The present invention relates to a fixing device having a fixing roller (including a belt-shaped roller) such as a heating roller, a pressure roller, or a heating pressure roller.

[Prior Art According to the Present Invention]

Conventionally, in this field, a roller having a core metal coated with tetrafluoroethylene resin is used as a heating roller in contact with a toner image, and a rubber layer is coated as a pressure roller in pressure contact with the heating roller to increase the heating / pressing time of the toner image. It is common to use a roller.

However, since the surface of the heating roller provided on the toner image side is close to a rigid body, when the toner image is pressed to transfer heat, it is less familiar to the paper surface and the unevenness of the toner image, and is effective. Less heat transfer. Therefore, the obtained image quality and fixability are worse than when the rubber roller is used on the toner image side, and the amount of curl generated on the sheet on which the toner image is fixed is large. On the other hand, when a rubber roller is used as the toner side roller, offset is increased due to poor releasability, and wear resistance is low, so wear occurs due to contact members (separation claws, sensors, etc.) and partial fixing failure and partial offset Will also increase.

Thus, both the rubber roller and the resin roller have advantages and disadvantages, and an elastic roller having these advantages has been desired.

On the other hand, a fixing roller provided with a resin layer on the surface and a rubber layer below the surface is proposed in Japanese Patent Publication No. 47-20747.

This fixing roller is formed by shrinking a heat-shrinkable tube in which a resin layer is created in advance. Therefore, the resin layer has uneven thickness, and the roller shape cannot be obtained unless the tube itself is thickly formed. In any case, when this fixing roller was used, sufficient fixing properties could not be obtained, and the heating temperature for heat fixing had to be raised considerably. It is considered that this decrease in fixing property is related to the resin film thickness.

However, when the film thickness is changed to be thin, the surface is easily scratched by a contact member such as a separating claw, the abrasion resistance is lowered, and sufficient fixing property cannot be obtained.

On the other hand, when fixing is performed with a constant film thickness, the fixing effect may be poor even if there is a sufficient pressure contact area. Conversely, if the pressure contact area is made small, the durability limit will be reached at tens of thousands of sheets and peeling of the resin film will be observed. Was given.

In the past, such a problem could not be solved easily, and various measures such as improving the fixing effect by complicated control by the heating means and variously changing the material of the fixing roller and the like were taken. There was no choice but to sacrifice either gender or stability.

[Object of the Invention]

In view of the above problems, the present invention pursues the cause, paying attention to the constitutional requirements in the state of fixing the rotating body provided with the resin layer on the upper layer of the elastic body layer, and has sufficient fixing effect and sufficient fixing effect. A fixing device capable of exhibiting excellent durability is provided.

Another object of the present invention is to provide a fixing device in which the elasticity of the elastic layer can sufficiently contribute to fixing and the fixing effect and durability are at a much higher level than in the past, and yet another object is to provide a complicated addition. It is an object of the present invention to provide a fixing device that can achieve the above object with a simple structure without requiring a structure.

[Summary of the Invention]

In order to achieve this object, the present invention defines the pressure contact area of the pair of rotating bodies of the fixing device and the film thickness of the resin layer of one rotating body, and is made of silicon rubber having a repulsion elastic modulus of 60% or more. A first rotating body having an elastic layer and a resin layer formed by applying and baking a fluororesin dispersion liquid on the elastic layer; and a first rotating body press-contacted with the first rotating body to form a press-contact region. In a fixing device having two rotating bodies and performing fixing in this pressure contact area, the thickness (Tμm) of the resin layer of the first rotating body has a relationship with the width (Nmm) of the pressure contact area, Is a fixing device.

In particular, the thickness T (μm) of the resin layer and the width N of the pressure contact region
(Mm) is the lower limit Further, the above-mentioned ones have further excellent effects in the present invention.

Further features of the present invention will be clarified below by the description of the embodiments.

Example of the present invention

FIG. 1 is an explanatory view of an embodiment of a fixing device of the present invention having a fixing roller of the present invention.

In FIG. 1, reference numeral 1 is a fixing roller on the side in contact with an unfixed toner image, and 2 is a pressure roller that rotates in pressure contact with the fixing roller 1.
Both are examples of the fixing roller of the present invention. The specific configuration is as follows.

The fixing roller 1 is made of a relatively thin silicon rubber (0.3 mm or more in this example) on a cored bar 11 having good heat conduction such as aluminum.
Elastic layer 12 having a repulsion elasticity of 65% to 85% and a PFA (tetrafluoroethylene resin-
Perfluoroalkoxy ethylene resin copolymer), PTFE
Fluorine resin such as (tetrafluoroethylene resin) is thinner than the elastic layer 12 (predetermined thickness within the range of 10 μm to 25 μm in this example),
It has a resin layer having a film strength of 50 kg / cm ² or more. Similarly, the pressure roller 2 is thicker than the thickness of the silicon rubber elastic body layer 12 on the cored bar 21 made of stainless steel or iron (in this example, a predetermined thickness within the range of 4 mm to 10 mm), and has a repulsion elastic modulus. 65
% To 85% of the elastic layer 22 and a fluorine resin such as PFA or PTFE on the elastic layer 22 which is thinner than the thick elastic layer 22 (5 μm in this example).
To a predetermined thickness within a range of 35 μm), and a resin layer 23 having a film strength of 50 kg / cm ² or more.

In FIG. 1, the rollers 1 and 2 form a pressure contact area M (hereinafter referred to as a nip) for heating and pressing and fixing the toner image by a pressure means (not shown).

This nip is not uniform and is small at the center of the roller and large at both ends of the roller. The minimum value of the nip width (or, preferably, the average nip width) is determined by the relationship with the resin film pressure described later.

These rollers 1 and 2 are formed by the manufacturing method shown in FIG. 3 or a method conforming to its purpose.
Briefly, it includes the following steps.

A rubber layer vulcanized and molded on the core metal (heat conductivity 1.4 × 10 ^-4 ~
1.5 × 10 ⁻³ ) to form a desired silicone rubber roller. A preferred shape is an inverted crown type in which the central portion has a slightly smaller diameter than both ends. The surface of this rubber roller is coated with unbaked fluororesin such as dispersion (a fluororesin powder dispersed in water with a surfactant), enamel or powdered fluororesin over the entire length of the rubber roller by spray coating, electrostatic coating or powder coating. Apply it to a uniform thickness by a method such as body painting. The dispersion is heated to, for example, a glass transition point of 327 ° C. or higher of the crystal melting point of fluororesin to form a film-shaped resin coating. Therefore, the silicon rubber roller coated with the unsintered fluorine resin needs to be heated to a crystal melting point or higher (PTFE: 327 ° C or higher, PFA: 306 ° C or higher).

However, although the silicone rubber itself has excellent impact resilience and rubber characteristics such as compression set, it is more than 300 ° C, let alone 3
When heated above 06 ℃ or 327 ℃, smoke or depolymerization occurs. These not only hinder the formation of a good quality fluororesin layer, but also impair the rubber properties of the silicone rubber itself. Therefore, when the rubber layer is overheated, the roller does not have the function of the rubber layer and does not have the characteristics of the resin layer, so that the condition suitable for fixing is completely lost.

For these reasons, in the examples of the present invention, the silicon rubber roller itself is kept under heating at a low temperature (up to 300 ° C. or less) so as not to cause smoking or depolymerization, and the crystal is formed in the coating layer of the fluororesin. A firing method that gives a high temperature state above the melting point was adopted.

Specifically, a method of rapidly heating the unsintered fluororesin on the surface while rapidly cooling the rubber layer from the inside of the core bar, or the dielectric loss tangent of the liquid fluororesin (dispersion, enamel) itself is the dielectric of the rubber layer. In addition to the dielectric heating method (see FIG. 3) utilizing the fact that it is greater than the tangent, any method that is suitable for this purpose is suitable for the present invention.

Although a thermal gradient is substantially formed in the thickness direction of silicon rubber by this method, the temperature of about 260 ° C to 280 ° C is higher than the crystalline melting point of unburned fluororesin (specifically, 327 ° C for PTFE). A baking temperature of 340 ° C. to 380 ° C. above ℃ is given for about 5 to 10 minutes.After this baking, this roller is rapidly cooled, and the crystallinity on the silicon rubber roller is 95% or less by this rapid cooling. A baked fluororesin surface layer showing resin characteristics such as a tensile strength of 50 kg / cm ² or more and a contact angle with water of 100 degrees or more is formed in a strong adhesion state to a rubber roller and is sufficiently thick.

Therefore, in the fixing roller 1 and the heating roller 2, the lower silicon rubber itself exhibits desired rubber characteristics almost the same as before the resin layer formation, and the surface fluororesin layer exhibits completely baked resin characteristics. The adhesion of the layer is strong.

Referring back to FIG. 1, another configuration of the fixing device will be described.

Reference numeral 3 denotes a heater such as a halogen lamp for heating the fixing roller from the inside, and the surface temperature of the fixing roller is the optimum temperature (at which the toner can be always melted by the heater 3, the temperature detecting element 4 and the control means 31). Specifically, 160 ° C to 200
℃) is maintained.

Reference numeral 5 denotes an offset prevention liquid application means that also serves as a cleaning means for applying an offset prevention liquid such as silicon oil to the surface of the fixing roller. The coating means 5 may be felt-like, but a web is used in this example. The web 51 containing the offset prevention liquid is brought into contact with the fixing roller 1 by the elastic pressing roller 52 such as silicon sponge, and a small amount of the offset prevention liquid is applied to the surface of the fixing roller 1. The web 51 is a take-up roller.
By 53, the web is gradually taken up from the supply roller 54, and the contact surface of the web with respect to the fixing roller 1 is sequentially recognized by the control means (not shown).

The recording paper P carrying the unfixed toner image T is fed to the entrance guide 6
The toner image T is permanently fixed on the recording paper P by passing between the roller pair 1 and 2 while being guided by the sheet.
The separation claw 41 that contacts the surface of the roller 1 is provided to separate the recording material from the surface 1 of the roller.

The fixing rollers 1 and 2 formed in this way have a characteristic that has not existed in the past, that is, they have sufficient impact resilience because the fluororesin is completely baked without thermally deteriorating the characteristics of the silicone rubber. It enables the use of silicone rubber with a low compression set, has excellent surface releasability and wear resistance, and has sufficient elasticity and high durability. Moreover, even if the stress generated when the toner image is fixed on the recording paper is concentrated between the silicone rubber layer and the fluororesin layer, the strength of the fluororesin layer is high and the adhesion between them is good. Such sudden peeling did not occur, and the number of durable sheets used was improved by several steps. In the above example, the durability of 200,000 sheets was exhibited.

Specific examples will be given.

The fixing roller 1 has an average thickness of about 17 μm (minimum film thickness of 15 μm to maximum film thickness) on a silicon rubber having a thickness of 0.5 mm and a repulsion elasticity of 70%.
20μm), and has a PTFE resin layer with a film strength of about 150Kg / cm ² , the outer diameter of the central part is 39.8mm and the outer diameters of both ends are 39.8mm + 100μ
A roller of m (reverse crown amount: 100 μm) was used.

This roller was manufactured as shown below, and an aluminum core bar with a central diameter of 38.75 mm and a reverse crown amount of 100 μ was prepared as the core bar, and the surface was sandplasted to degrease / degrease.
After drying, wrap a silicone rubber sheet through the primer, press vulcanize at 150 ° C for 40 minutes, then
After secondary vulcanization at 00 ° C. for 2 hours, the rubber was uniformly ground to a thickness of 0.5 mm.

Then, a fluororesin dispersion was applied by spray coating to a thickness of 25 μm, and the rubber was heated at 260 ° C. to 280 ° C. and baked at a temperature of 350 ° C. for 10 minutes by dielectric heating combined with infrared external heating. .

As the pressure roller 2, a roller having an outer diameter of 39.9 mm in which a PFA resin layer of 20 μm is coated on 6 mm silicon rubber was used.

This roller was manufactured as shown below.

Prepare an iron core with an outer diameter of 27.86 mm as the core, degrease and dry the surface with a sand plast, then wrap a silicone rubber sheet with a primer,
After press vulcanization for 0 minutes and secondary vulcanization at 200 ° C. for 1 hour, the rubber was ground to a thickness of 6 mm. Further, PFA resin powder was applied to the rubber roller to a thickness of about 20 μm and baked for 10 minutes in the same manner as the fixing roller to manufacture a pressure roller having an outer diameter of 39.8 mm.

Using these rollers 1 and 2, the surface temperature of the fixing roller is increased to 170
When fixing the toner while controlling the temperature at ℃, the toner shows exceptional fixability and the generation of offset toner is 1/5 or less compared to the best toner in the past, and the replacement period of the cleaning member is extended 5 times or more. it can. Further, according to the above, the image quality is good and the image is hardly crushed, and the fixing property is stable even when the fixing is 300,000 or more. This means that the number of durable sheets used did not reach the endurance limit even after fixing 500,000 sheets.

In the above structure, the important structure is as shown in FIG.
The thickness t ₁ of the elastic layer 12 of the fixing roller, the resin layer 13 of the fixing roller
The thickness t _{2 of} the pressure roller, the thickness t ₃ of the elastic layer 22 of the pressure roller, and the thickness t ₄ of the resin layer 23 of the pressure roller have the following relationship.

That is, t ₁ > t _{2 with the} roller 1 and t ₃ > ₄ with the roller 2, and preferably t ₄ <t ₂ <t ₁ <t _{3 With} this configuration, basically, the mutual addition of the fixing roller and the pressure roller is performed. Due to the effect, the defects of each other are complemented and the advantages of each other are improved, and the obtained image quality and fixing property can be made excellent and the durability becomes excellent.

The basis for determining the numerical value of the present invention will be described with reference to FIGS. 4 and 5.

In these examples, a fixing roller with an outer diameter of 40 mm is prepared, in which the thickness of the silicone rubber is 0.5 mm and the surface layer of which is a tetrafluoroethylene resin (PTFE) layer is provided with a predetermined thickness, and the pressure roller has an outer diameter of 40 mm. It is based on an experiment in which an elastic roller, a pressure contact width of these roller pairs is 5 mm, a paper feeding speed is 200 mm / sec, and a fixing roller surface temperature is 160 ° C. As the paper on which the toner image is fixed, a paper having an average surface roughness of 13 to 15 μ and poor surface property was used. This is because it is particularly easy to judge when observing how much the fixing roller surface can follow the unevenness of the paper.

In FIG. 4, the minimum width of the pressure contact area between the fixing roller 1 and the pressure roller is set as a predetermined reference value, and the film thickness T of the resin layer on the elastic layer of the fixing roller 1 is variably set to determine the durable number of the fixing roller 1. The relationship between the fixing ratio of the image quality fixed by the sawtooth pressure contact area is shown. In Fig. 4, the number of endurance sheets in semi-logarithm on the left axis,
The right axis shows the fixing rate at equal intervals, the experimental curve shows the relationship between the film thickness (T) and the number of durable sheets (S), and the broken line curve shows the relationship between the film thickness (T) and the fixing rate (%). It expresses a curve.

These curves show that the width (N) of the pressure contact area is 4mm, 7mm, 10mm, 1
It is drawn for 2mm and the film thickness (T) is 7μ, 15μ, 22μ, 30μ
It is obtained by plotting the data at the time. The thermal conductivity of each fixing roller on the heating side used in this experiment is almost Was the same as Therefore, no extra condition is added to the measurement of the fixing rate described later. Fixing was performed by printing 38 sheets / minute of Japanese Industrial Standard A4 size at a speed of 200 mm / sec. The outer diameter of each roller is about 50 mm, the pressure roller is a JIS A rubber hardness 40 degree rubber roller, and the nipple 4 mm has a total load of 50 Kg and the nipple 7 mm.
Has a total load of 65 kg, and the nipple 10 mm has a total load of 80 kg.

In FIG. 4, in this example, the durable number of sheets is 100,000 or more and the fixing rate is 80% or more, which are set as good conditions, and therefore these values are shown on the common horizontal axis.

Generally, when the thickness of the coating layer of the fixing roller becomes large, a thermal insulating layer is formed, so that internal heat does not appear on the surface.
If this thickness is too thin, sufficient heat storage cannot be achieved, and the fixing effect may deteriorate. In addition, it is considered that the thickness of the resin layer on the elastic layer may be increased if the wear resistance is simply considered.

However, in the case where the resin layer is provided on the elastic layer as in this example, the durability including the problem that the resin layer is peeled off must be considered, and even if the thickness of the resin layer is reduced. Experiments have shown that the fixing rate is good even if the fixing rate is poor or the resin layer is thick. Then, the present inventors have concluded that this pressure contact region is an important durability parameter.

FIG. 4 shows the background of the present invention. In this figure, it can be understood that the nip width N shows almost no influence when the resin film thickness is 16 μ or less in the fixing rate, and conversely when the resin film thickness is 26 μ or less in the durable sheet number S. it can. It was also confirmed that the nip width N has a contradictory effect that the smaller the number of durable sheets is, the more the durability is increased, and the larger the fixing rate is, the more the fixing ability is improved.

That is, unless the resin film thickness and the nip width are properly configured, it is impossible to obtain a sufficient fixing rate and a durable number of sheets, and there are many restrictions and complications on other heating means, pressurizing means, fixing roller material, and the like. I have to compel.

In other words, establish the relationship between the resin film thickness and the nip width,
The fixing device having such a structure can solve such a problem.

In this specific example, the durability is 100,000 or more and the fixing rate is 80%.
If the above is mentioned, about 6.0μm to about 25.0μm Nip 7mm for 4mm Nip
Approx. 10,4 μm Approx. 28.1 μm Nip 10 mm Approx. 1
There are 6.0 μm to about 32.2 μm.

FIG. 5 shows the resin film thickness T (μ) and the nip width N of the present invention.
The area where the relationship with (mm) is approximated by a straight line is specified.

If we explain this area with an equation, And, as a preferable condition, the durability of 200,000 sheets is exceeded, Is.

Further, if the upper and lower limits of the resin film thickness T (μ) are set, the average film thickness is preferably 5 μ or more and 35 μ or less, and the minimum film thickness is optimally 5 μ or more in consideration of heat capacity or other unstable factors. Is.

The plots in FIG. 5 are the upper and lower limit values of the data in FIG. 4 of the durable number of 100,000, 200,000 or more and the fixing rate of 80% or more, and the boundary part of the above area of the present application. Is located in.

As can be understood from the above, the present invention provides a structure that can solve the conventional problems, that is, the film thickness of the resin layer on the elastic body of the rotating body and the width of the pressure contact region where the fixing action of the rotating body pair is performed. Since the relationship is within the above range, excellent durability and excellent fixing effect can be obtained.

If the resin layer exceeds 35μ in the above range, the effect of the lower elastic layer is small, and special characteristics may be required to improve the fixing property.Therefore, the elastic effect of the elastic layer is set to 35μ or less. It is preferable to make use of it.

As the elastic layer, a rubber layer is preferable, and when heat resistance is required, silicone rubber having a repulsion elastic modulus of 60% or more is suitable. The resin layer preferably has a film thickness of 10 to 25 μ. In order to obtain a more stable fixing rate, the impact resilience is 65 to 85% and the film thickness is 15 to
25μ is optimal. Further, the resin layer is preferably a fluororesin, and particularly, the tensile strength of the resin is preferably 50 Kg / cm ² or more, and more preferably 150 Kg / cm ² or more. Further, when a resin layer is provided on the rubber layer, it is preferable that the adhesion strength between them is 20 g / 10 mm width or more by applying the manufacturing method described later.

Incidentally, in FIG. 5, the linear approximation formula that defines the lower limit of the resin film thickness with a nick width of 10 mm changes significantly. This belongs to the intermediate thickness even in the range of the present invention such as a film thickness of 16μ or more, the synergistic effect of the nip width and the film thickness to compensate for the variations of the elastic layer and the adhesive layer generated on the inner layer surface is utilized, and the allowable range. It is believed that this is due to the expansion of

The fixing rate is obtained by the following method.

Form a solid black circular image with a diameter of 24 mm. The image density
The image is D _0, and the image is a non-woven fabric called Kojin Wiper (trade name: Paper Waste manufactured by Kojin Co., Ltd .; it has a softness like tissue paper and a grainy rough surface, a crepe rate of 32 ± 3%, a weight of 35. ± 3g / m ² , long-term strength (vertical) 0.
Shows the above 4 kg / 15 mm, the image density after rubbing back and forth 10 times under a load of 40 g / cm ² in disposable wiping sheet) having a thickness of about 200μm When D _1, Retention = (D ₁ / D It is determined by ₀ ) x 100%.

It should be noted that the densities D ₁ and D ₀ are values measured by a Macbeth reflection densitometer, and D ₀ is within a range in which the image density is adjusted so that the image density is 1.0 ≦ D ₀ ≦ 1.1.

Practically, a durable number of sheets of 100,000 or more and a fixing rate of 80% or more can be said to be preferable fixing roller conditions in terms of stability and reliability.

The above numerical values are based on the measuring method described later.

First, regarding the impact resilience of rubber, tensile stress, and elongation, JI
It was measured according to the measuring method according to S K6301.

Specifically, first the test piece is 5 mm (width) x 20 mm (length) x 3
A dumbbell-shaped vulcanized silicone rubber of mm (thickness) was coated with a fluororesin dispersion and heat-treated according to the embodiment of the present invention, and a silicone rubber alone was further prepared.

That is, the fluororesin coating layer is heated to a temperature higher than 327 ° C. while the silicone rubber is kept under heating at 300 ° C. or lower, so that the fluororesin coating (this resin coating) is baked on the silicone rubber. The characteristics of the above are the contact angle 100
A tensile strength of 50 Kg / cm ² or more, and a tensile strength of 50 Kg / cm ² or more). After that, remove the silicone resin test piece after removing the fluororesin layer on the surface.
Tensile stress and elongation are measured by the measuring method described in JIS K6301.

About impact resilience, 12.7 ± 0.13mm (thickness) × 29.0mm
After making a silicone rubber test piece of (diameter), apply the same heat treatment as above, and then treat it as a single rubber
Measure according to K6301.

Further, regarding the silicone rubber on the fixing roller produced based on the embodiment of the present invention, the silicone rubber having the baking coating film of the fluororesin on the surface layer is 5 (width) × 20 (length) × 0.3 to 0.5 from the core metal. After peeling with a size of mm (thickness), the fluororesin layer is peeled off from the silicone rubber, and the tensile stress and elongation are measured by the method described in JIS K6301.

At this time, it is desirable that the thickness of the silicone rubber be closer to a uniform value, but since it is difficult to prepare a sample, it is difficult to be uniform in practice, so the measured value is about 70 to 80 compared to the measured value using the test piece described above. Compare as indicating the value of%.

The impact resilience of 65 to 85% indicates the ability of the fixing roller to elastically follow the unevenness of the paper and the deformation due to the presence or absence of toner during a short fixing time, which causes the fixing roller to deform to the unevenness of the paper toner. However, the range that can effectively apply heat and pressure is specified.

Next, a method of measuring the resin of the manufactured roller will be described.

First, the crystallinity of the resin is measured by an infrared absorption spectrum, but it may be measured by X-ray or specific gravity. The contact angle was measured using the drop method (Metal surface technology 17, No7 1966). In the actual measurement, the contact angle (value with respect to water) may be either a forward contact angle of 118 ° or a receding contact angle of 91 °, or either of them, or the average thereof may be 100 ° or more.

Next, for the elongation rate and tensile strength of the resin, only the resin film was taken out from the roller after manufacturing as a tanzaque type sample with a width of 15 mm × a length of 100 mm, and this was 20 mm between chucks and 250 mm pulling speed.
It was measured by performing a tensile test in minutes. For example, if the tensile strength is 95 kg / cm ² and the elongation is 80%, the minimum value is 72 kg / c.
The maximum value is 180 Kg / cm ² , and the maximum value is 120% at m ² and 60%, respectively.

Regarding the peel strength of the resin, cuts are made with a cutter knife at intervals of 10 mm width in the circumferential direction of the roll, the partially peeled fluororesin layer is pulled by a tension meter, and the maximum value is taken as the peel strength.

FIG. 3 shows a firing method of the fixing roller of the present invention. The device shown in the figure is a specific example of a heating system that uses both an induction heating device and infrared external heating. The magnetron 105 and the high frequency generated from the magnetron 105 (950 KHz to 2450 MHz)
A resin container 102 that can be opened and closed, and has a waveguide 106 for transmitting a wave and a metallic high-frequency reflection plate 103 on the inner surface connected to the waveguide.
And two infrared lamps for upper and lower infrared heating
1 and has a reflective shade.

In the resin container 102, a fan 100 for generating an air flow in the hollow of the fixing roller 1 as a fixing roller and a fan 101 for generating an air flow in the container 102 are respectively provided from driving means outside the container. It is rotatably provided by driving. This container can be opened and closed around the fulcrum 108 and has a handle at the top.
Numeral 09 is fixed to the arm 107 for positioning the flange 1A of the roller 1 at the bottom.

110 is a control means of the device, which is a drive means 104 and a magnetron 10
5 and the infrared lamp 111 are operated by a variable timer (not shown) for a predetermined time by inputting a closed state of the container and a predetermined start signal.

Since the fixing roller 1 has a silicone rubber layer as a lower layer and a fluorine resin dispersion on the surface, a large amount of high frequency is absorbed in the dispersion having a comparative electric conductivity higher than that of the silicone rubber layer. Therefore, the fluororesin dispersion is rapidly heated to a high temperature of 340 ° C. to 350 ° C. by high frequency, infrared rays and heating in a constant temperature bath. At this time, since the silicone rubber layer has a low high frequency absorption rate, it is heated to a temperature of about 280 ° C. or lower rather than being heated to a temperature higher than that of the discharge purgeon. This makes it possible to obtain the roller characteristics described above.

In the above examples, the fluororesin dispersion is, for example, tetrafluoroethylene resin dispersion D-1 manufactured by Daikin.
Is.

In addition to the above-described embodiments, the present invention includes roller-shaped belt-shaped rollers (for example, transfer simultaneous fixing and intermediate belt), cleaning rollers, and release agent supply rollers as fixing rollers. In particular, since it has the releasability and elasticity of the fluororesin, it has transferability and cleaning property (however, the cleaning roller performs cleaning according to the order of surface energy, etc.) Prevents uniform application of the agent and transfer unevenness, and exerts the advantages of excellent abrasion resistance in each application.

The above-mentioned thickness is represented by the average thickness of each layer, and it is optimal that it is the minimum thickness.

Further, FIG. 1 shows an example of a heat fixing device, which is preferable as an embodiment of the present invention. A pressure fixing device for pressure fixing a toner image with a light pressure, a pressure for simultaneous transfer fixing, etc. The present invention can be applied to a fixing device or a heat fixing device.

Further, although the above example has a two-roller configuration, it includes a heating roller, a pressure roller, a release agent supply roller of a fixing device having three or more rollers, or a cleaning roller and other belt-shaped rollers. The device is also included in the present invention.

Although the above embodiment does not provide an adhesive layer between the resin layer and the rubber layer, the present invention also includes one having an adhesive layer.

[Effect of the present invention]

The present invention solves a problem that has not been solved by focusing on the relationship between the resin layer on the elastic layer and the pressure contact region between the pair of rotating bodies. The wear resistance of the resin layer is utilized to improve the fixing effect. Since it has an elastic layer that can be formed, the durability and fixing effect can be made stable.

When the thickness of the resin layer in the present invention is in the range showing the above constitution, the durability of 100,000 sheets or more can be obtained, and a high degree of fixing property can be maintained. The present invention is particularly effective when a fluororesin is provided on the silicone rubber layer.

The effects common to the rotating body for fixing (including the belt-shaped roller) are excellent in abrasion resistance and surface releasability, and the surface characteristics of the resin layer and the elastic characteristics of the rubber are fully exerted, so that the toner image and other It has an excellent effect of following the roller and has a very long life.

In addition, since the thermal efficiency of fixing is high and the temperature required for fixing can be reduced (for example, about 20 ° C.), power consumption is reduced, and high-speed fixing recording can be achieved even with an apparatus having a small power distribution.

The surface of the fixing rotator becomes considerably smooth, and the necessity of polishing can be reduced.

[Brief description of drawings]

FIG. 1 is an explanatory view of an embodiment of a fixing device of the present invention, FIG. 2 is a partially enlarged explanatory view of a fixing roller pair, FIG. 3 is an explanatory view of an embodiment of a manufacturing method of a fixing rotator, and FIG. FIG. 5 shows the relationship between the fixing ratio and the number of durable sheets when the nip width is changed with respect to the film thickness, showing the data for determining the numerical range of the present invention. FIG. 5 shows the relationship of the constitution of the present invention. It is a relationship diagram between and a resin film thickness. 1 is a fixing roller, 2 is a pressure roller, 12 and 22 are silicone rubber elastic layers, 13 and 23 are fluororesin layers, and M is a nip width.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Masahiro Goto Inventor Masahiro Goto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Isamu Sakane 5-13-13 Ichiriyama, Otsu, Shiga Prefecture Stocks (56) References JP-A-56-159676 (JP, A) JP-A-59-102266 (JP, A) JP-A-59-45478 (JP, A) JP-A-59- 172668 (JP, A) JP 58-23072 (JP, A) JP 57-89785 (JP, A) JP 55-137558 (JP, A) JP 59-217010 (JP, A)

Claims (3)

[Claims] 1. A first rotating body having an elastic layer made of silicon rubber having a repulsion elastic modulus of 60% or more, and a resin layer formed by coating and baking a fluororesin dispersion liquid on the elastic layer. And a second portion that press-contacts the first rotating body to form a press-contact region.
In the fixing device which has a rotating body and performs fixing in this pressure contact area, the thickness T (μm) of the resin layer of the first rotating body has a relationship with the width N (mm) of the pressure contact area, Is a fixing device. 2. The fixing device according to claim 1, wherein the thickness T (μm) is 5 μm or more and 35 μm or less. 3. The relationship between the thickness T (μm) of the resin layer and the width N (mm) of the pressure contact region is: Claims 1 and 2 characterized in that
The fixing device according to the item.