JPH0680473B2 - Roller for fixing and fixing device having the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a heating roller, a pressure roller, or a heat pressure roller, which is 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 roller such as a roller (including a belt-shaped roller) and a fixing device having the fixing 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, and wear is caused by the abutting member (separation claw, sensor, etc.), 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, there is proposed a fixing roller having a resin layer on the surface and a rubber layer below the resin layer.

However, since these only show that a mixed layer of fluororubber and fluororesin or a tetrafluoroethylene tube is provided on the rubber layer, it has practical durability, abrasion resistance and fixing ability. Could not get.

As a result of intensive research conducted by the inventors on the cause of this, fixing rollers having a resin layer on these rubber layers cause partial peeling between the rubber layer and the resin layer at the end of their durability, and partial wear of the resin layer is observed. It was This phenomenon is considered to be related to the adhesiveness between the rubber layer and the resin layer.

For example, when a mixed layer of fluororesin and fluororubber is provided on the rubber layer, the fixing property is good, but the releasability gradually decreases due to the paper passing durability, and the fixing with the offset toner is performed after about 50,000 sheets. Roller stains occur.

Further, the one in which tetrafluoroethylene tube is provided on the rubber layer is disclosed in JP-B-47-20747.

This roller is made by polishing the surface of a silicone rubber roller, applying an adhesive, covering it with a heat-shrinkable tube (FEP: fluorinated ethylene propylene) with a diameter larger than the diameter of the rubber roller, and heat-shrinking it at 104.4 ° C. It was heated at 182.2 ° C for 1 hour. However, in this method, it is difficult to obtain a roller having a predetermined shape because the amount of heat shrinkage is not uniform, and there is a problem that the inner surface must be cleaned extremely well after the resin tube is formed in advance. There is.

Furthermore, even when the above problem is solved, when the roller is used as a fixing roller, the durability is excellent, but the fixing property is poor, and the characteristic is the same as when only the resin is used for the surface layer, On the contrary, since the heat conduction in the radial direction of the roller is poor, it is very inferior to the resin roller in terms of heat followability.

A roller in which fluororubber is coated on fluororubber has also been proposed. However, since the fluororubber can withstand the firing temperature of fluororesin (PFA, PTFE) in general, the fluororesin has a sufficient thickness. Although it is possible to form a film by firing with, the fixing property is not sufficient in reality, and the durability and the adhesiveness between the rubber layer and the resin layer pose problems when the fixing roller nips and conveys the sheet. A slip may occur between these layers due to the generated local stress, and if this occurs, the rubber layer and the resin layer are easily peeled off, and the resin layer is torn by a separating claw or the like due to paper passing durability.

[Purpose of the present invention]

The present invention provides a fixing roller and a fixing device including the fixing roller, which is epoch-making for the fixing roller and the apparatus including the fixing roller.

An object of the present invention is to provide a fixing roller which has surface resin characteristics, has moderate elasticity as a whole, and can be superior in fixing property, abrasion resistance, and durability as compared with conventional fixing rollers, and a fixing device having the fixing roller. is there.

[Summary of the Invention]

The present invention achieves the above object, and is characterized by new constitutional requirements, focusing on the relationship between the resin layer and the rubber layer of the fixing roller.

That is, the present invention provides a PFA or PTFE layer on the silicone rubber layer.
In the fixing roller and the fixing device having the fixing roller, the fluorine resin is applied at a temperature equal to or higher than its crystal melting point while the silicone rubber layer is heated at a low temperature. Above 35 μ, the impact resilience of the silicone rubber layer is 42% to 85%, and when this film thickness is T (μ) and this impact resilience is E (%),
A fixing roller and a fixing device having the same are characterized in that the relationship between T and E is T ≦ 0.75E−26.4.

Particularly, the present invention is particularly effective when the rubber layer is a silicone rubber layer and the resin layer is a tetrafluoroethylene resin layer which is fired at 327 ° C. or higher.

According to the configuration of the present invention, durability is conventionally at most tens of thousands of sheets, but it is possible to perform 100,000 sheets or more by normal fixing, and the thickness of the resin layer is within the range of 10 μ to 25 μ. Thus, the fixing effect can be further improved by setting the number of sheets to 200,000 or more, and further in the range of 15 μ to 20 μ.

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.

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 silicone rubber roller of the desired shape. 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).

Although the silicon rubber itself has excellent rubber properties such as impact resilience and compression set, when heated to 300 ° C or higher, or even 306 ° C or 327 ° C or higher, fuming causes depolymerization. These not only hinder the formation of a high-quality fluororesin layer, but also impair the rubber properties of the silicone rubber itself. Therefore, the heating of the rubber layer loses the condition suitable for fixing because the roller does not have the function of the rubber layer and the characteristic of the resin layer.

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 crystal melting point of unbaked fluororesin (specifically, PTFE A firing temperature of 340 ℃ to 380 ℃ above 327 ℃ is 5
It is given for about 10 minutes. After this firing, the roller is quenched. Due to this rapid cooling, the calcined fluororesin surface layer showing resin characteristics with a crystallinity of 95% or less, a tensile strength of 50 kg / cm ² or more and a contact angle of 100 ° or more with water on the silicon rubber roller in a state of strong adhesion to the rubber roller Moreover, it is formed 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 internally heating the fixing roller. 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 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 manner have sufficient impact resilience because they are completely non-existent, that is, the characteristics of the silicone rubber are not thermally deteriorated and the fluorine resin is completely baked. It enables the use of silicone rubber with less 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,
Since the adhesiveness of these is also good, the rapid peeling as in the past does not occur, and the usable durability number is improved by several stages. In the above example, the durability of 200,000 sheets was exhibited.

Specific examples will be given.

As fixing roller 1, 25 μm PTFE on 0.5 mm silicon rubber
It has a resin layer, the outer diameter of the central part is 39.8 mm and both ends have an outer diameter of 39.8 mm.
A roller of mm + 100 μm (reverse crown amount of 100 μm) was used.

This roller was manufactured as shown below, and an aluminum cored bar with a central diameter of 38.75 mm and a reverse crown amount of 100 μ was prepared as a cored bar, and the surface was sandblasted 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.

Next, apply 25 μm thick fluororesin dispersion to spray the rubber to a temperature of 260 ° C to 280 ° C and heat the resin to 350 ° C for 10 minutes by dielectric heating combined with infrared external heating. did.

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.

As a core metal, prepare an iron core metal with an outer diameter of 27.86 mm, sandblast the surface, degrease and dry it, then wrap a silicone rubber sheet with a primer and
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 having a thickness of 20 μm was applied to this rubber roller and baked for 10 minutes in the same manner as the above 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 5 times or more. You can prolong your life. Furthermore, when the above conditions were satisfied, the image quality was good and there was almost no crushing of the image, and the durable number of sheets used exceeded 200,000, and stable fixing was exhibited even when fixing 300,000 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, the roller 1 has t ₁ > t _{2 the} roller 2 has t ₃ > t ₄ , and preferably t ₄ <t ₂ <t ₁ <t _{3 With} this configuration, basically, the mutual phase of the fixing roller and the pressure roller is The surplus effect complements each other's defects and improves each other's advantages, resulting in excellent image quality and fixability, and excellent durability.

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

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

FIG. 4 shows the fixing rate when the impact resilience of the lower silicone rubber layer is set to a predetermined value and the thickness of the upper resin layer is variably set.

The plot in Fig. 4 is rubber layer impact resilience 40%, 50%, 65
%, 80%, and resin layer thicknesses of 10μ, 20μ, 30μ were tested, and the thermal conductivity of each fixing roller was almost Was the same as

As a result, when the impact resilience is 40% and 50%, the thinner the resin layer is, the better the fixing rate is, but the durability is only about 10,000 sheets. Conversely, when the resin layer is about 5 to 10 μ, the fixing rate is 70%. I lost the practicality by dividing the percentage. Further, it was confirmed that the fixing property tends to be improved as the impact resilience increases. However, when the resin layer is thin, it was also observed that the resin layer was peeled off from the rubber layer due to abrasion due to contact with paper, a separation claw, a temperature detection sensor, or the like. In this respect, if the resin layer has a sufficient impact resilience, the durability is 100,000 sheets or more when the resin layer is 5 μm or more, and 200,000 sheets or more is excellent when the resin layer is 10 μm or more. On the contrary, if the thickness of the resin layer exceeds 35 μ, the fixing rate cannot be improved even if the impact resilience of the rubber layer is increased. This reveals that the thickness of the resin layer determines whether the characteristics of the rubber layer are the characteristics of the fixing roller.

Further, in order to examine the thickness of the resin layer and the impact resilience of the rubber layer, FIG. 5 shows the relationship between the film thickness and the impact resilience at the fixing rates of 70% and 80% from FIG.

As will be understood from this, an increase in the film thickness deteriorates the fixing rate, and if the film thickness is reduced to obtain a good fixing effect, the durability is deteriorated, so the thickness is 5 μm or more, and practically 10 μm or more. Preferably. If a resin layer is provided on the rubber layer with a thickness setting of 10 μm or more, there will be no portion thinner than 5 μm, so stable quality assurance can be performed in the durability manufacturing process.

To give an example of these film thicknesses and impact resilience, resin film thickness 10μ
On the other hand, a fixing roller having a rubber layer impact resilience of 49% or more to obtain a fixing rate of 70% or more and about 58% or more to obtain a fixing rate of 80% or more is preferable. A fixing roller having a rubber layer impact resilience of 55% or more for obtaining a fixing rate of 70% or more and about 65% or more for obtaining a fixing rate of 80% or more is preferable for a thickness of 15 μm or more.

As for the film thickness and the fixing rate, it is preferably 35 μ or less to obtain a fixing rate of 70% or more, and 25 μ or less to obtain a fixing rate of 80% or more.

Also, when the fixing rate is 80% or more, the impact resilience is 60 to 85% (85% is the upper limit for silicone rubber), and the film thickness is 10 to 25μ, which gives a more stable fixing rate and durability. Repulsion elastic modulus 65-85%, film thickness 15
~ 25μ is optimal.

With the configuration in the above range, a fixing device having durability and a high fixing effect can be obtained.

In the above range, a slightly delicate condition is included, but as a condition common to those that can obtain a fixing rate of 70% or more, the tensile strength of the resin layer is 50 Kg / cm ² or more and the rubber layer and It was confirmed that the adhesion of the resin layer had a strength of 20 g / 10 mm width or more.

When the rubber layer is silicone rubber, rubber hardness (JISA)
Is preferably 30 degrees or more and 80 degrees or less, and has an elongation of 150% or more and 100%
The tensile stress is preferably 10 kg / cm ² or more.

Based on the above trends and numerical values, the relationship between the film thickness and the impact resilience can be summarized as conditions for obtaining an effect of a fixing rate of 70% or more.
Regarding the film thickness T (μm) of the resin and the impact resilience E (%) of the rubber layer, the conditions are defined by 42 ≦ E ≦ 85, 5 ≦ T ≦ 35 T ≦ (0.75E-26.4). With a fixing roller having this condition, the durable number of sheets is 100,000 or more. As a preferable example, a structure that obtains a fixing ratio of 80% or more is a condition defined by 58 ≦ E ≦ 85, 10 ≦ T ≦ 25 T ≦ (0.65E-27.3). According to this, the number of durable sheets is over 200,000. Fixing rate
15 ≦ T ≦ 25 is added to the condition of 80% or more, so that the number of durable sheets can be increased from 300,000 to 500,000.

According to the present invention, the greater the impact resilience, the greater the resin film thickness, the higher the fixing effect, and the greater the durability.

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 durability of 100,000 sheets or more and a fixing rate of 70% or more can be said to be preferable fixing roller conditions in terms of stability and reliability.

The above conditions 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 of 300 ° C. or lower while the fluororesin coating layer is heated to a temperature higher than 370 ° C. The characteristics are the above-mentioned contact angle of 100 degrees or more, elongation of 50% or more, and tensile strength of 50 kg / cm ² or more). After that, the silicone rubber test piece after peeling off the fluororesin layer on the surface was JI
Tensile stress and elongation are measured by the measuring method described in S 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 42 to 85% indicates the ability of the fixing roller to follow the unevenness of the paper and the deformation due to the presence or absence of toner with elasticity 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.

In the experiment, in the fixing roller having a fluorine resin layer of 5 to 35μ on the surface layer, the impact resilience of the lower silicone rubber is 42 to 85%.
Then, it was found that a good fixing property was exhibited.

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 roller, 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 MHz to 240 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 silicon rubber layer as a lower layer and a fluororesin dispersion on the surface, a large amount of high frequency is absorbed in the dispersion having a relative dielectric constant larger 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 the present invention, in addition to the above-described embodiment, as the fixing roller, a roller-shaped other belt-shaped roller (for example, an intermediate belt for simultaneous transfer and fixing), a cleaning roller, and a release agent supply roller are included. In particular, since the releasing property of the fluororesin is provided, the transferability and the cleaning property are provided (however, the cleaning roller performs cleaning in the order of surface energy, etc.), and the releasing effect is obtained by the effect of the elasticity. 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, the above-mentioned example has a two-roller structure, but 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]

INDUSTRIAL APPLICABILITY The present invention includes a lower rubber layer that provides a practical range of the resin layer, and takes advantage of the mold release property and abrasion resistance of the resin layer and provides elasticity that can improve the fixing effect. The effect can be stable.

When the thickness of the resin layer in the present invention is 10 μ or more, the durability is 15
It can be improved to more than 10,000 sheets, and if it is set to 15μ or more, durability of 200,000 sheets or more can be obtained, and the fixing effect is reduced by the impact resilience of the rubber layer to compensate for the drawback Fixability can be maintained. The present invention is particularly effective when a fluororesin is provided on the silicone rubber layer.

The effects common to the fixing roller (including a belt-shaped roller) of the present invention are excellent in abrasion resistance and surface releasability, and the surface characteristics of the resin layer and the elastic characteristics of rubber are sufficiently exerted to obtain toner images and other It also has an excellent effect of following the roller, and has a very long life.

In the fixing device of the present invention, when the fixing roller is applied to one roller (including a belt) that presses the recording material, curling of the recording material is prevented, a fixed image is clear and the fixing property is good. Can be maintained for a longer period than ever before. Moreover, since the heat efficiency of fixing is good 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 roller of the present invention is 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 roller (including a belt-shaped roller) and a fixing device having the fixing roller according to the present invention.
FIG. 4 is a partially enlarged explanatory view of the fixing roller, FIG. 3 is an explanatory view of an embodiment of a manufacturing method of the fixing roller, and FIG. 4 shows data for determining the numerical range of the present invention. FIG. 5 is a diagram showing the relationship with the fixing rate when the rate is changed, and FIG. 5 is a diagram showing the relationship between the film thickness and the impact resilience rate in FIG. 4 based on the fixing rate in FIG. 1 is a fixing roller, 2 is a pressure roller, 12 and 22 are silicone rubber elastic layers, and 13 and 23 are fluororesin layers.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Isamu Sakane 5-13-13 Ichiriyama, Otsu City, Shiga Pref. S. Tay (56) Reference JP-A-57-89785 (JP, A) JP-A-59-74578 (JP, A)

Claims (2)

[Claims] 1. A fixing roller in which a fluororesin of PFA or PTFE is applied onto a silicone rubber layer, and the fluororesin is baked at a temperature equal to or higher than its crystalline melting point while maintaining the silicone rubber layer under low temperature heating. The film thickness of the fluororesin is 5 μ or more and 35 μ or less, the impact resilience of the silicone rubber layer is 42% to 85%, and this film thickness is T
(Μ), when the impact resilience is E (%), the relationship between T and E is T ≦ 0.75E−26.4. 2. A fixing roller comprising a PFA or PTFE fluororesin applied on a silicone rubber layer and baking the fluororesin at a temperature equal to or higher than its crystalline melting point while maintaining the silicone rubber layer under low temperature heating. In the fixing device, the film thickness of the fluororesin is 5 μ or more and 35 μ or less, the impact resilience of the silicone rubber layer is 42% to 85%, and this film thickness is T
(Μ), when the impact resilience is E (%), the relationship between T and E is T ≦ 0.75E−26.4.