JPH0695262B2 - Elastic rotating body for fixing and manufacturing method thereof - Google Patents

Description

TECHNICAL FIELD The present invention relates to a general elastic rotating body, particularly to an elastic rotating body having a resin layer on the elastic body, and further to a method for manufacturing the elastic rotating body. And, the elastic rotating body according to the present invention,
Specifically, it is optimally used as a conveyance roller or belt for papers in office equipment, especially as a heat fixing roller or belt.

(Background Art) Conventionally, many elastic rotating bodies in which a resin layer is provided on an elastic body have been proposed. These are regarded as important in the field of fixing devices, but in both cases, the adhesion between the elastic layer and the resin layer is low,
It was inferior in durability and wear resistance during use and could be put to practical use, but the replacement period was short.

In addition, the resin layer provided on the elastic layer cannot have excellent wear resistance unless it is fired at a temperature higher than the endurance temperature of the elastic layer. There was nothing that satisfied me enough.

On the other hand, the applicant of the present invention, as disclosed in Japanese Patent Application No. Sho, maintains the rubber elastic layer at a low temperature so as not to cause smoking or depolymerization by heating, while An elastic rotating body obtained by applying a high temperature state above the crystalline melting point to the resin layer applied on top and firing is proposed. According to this, it has surface resin characteristics, and has moderate elasticity as a whole, and can be made superior to the conventional elastic rotating body in fixing property, abrasion resistance, and releasability. (Japanese Patent Application No. 59-234780) However, even in the case of manufacturing this elastic rotating body, the adhesion between the elastic body layer and the resin layer is still insufficient, and it is not satisfactory.

(Object of the Invention) An object of the present invention is to provide a method of manufacturing an elastic rotating body that can further strengthen the adhesion between the elastic body layer and the resin layer, and an elastic rotating body obtained by the method. is there.

(Summary of the Invention) In order to achieve the above object, the present invention provides a manufacturing method for manufacturing a fixing elastic rotating body having a resin layer on an elastic body,
The surface of the elastic body is made to contain a surfactant in advance, and a resin dispersion mixed with an unbaked resin material is applied on this elastic body, and then the resin dispersion is heated to a high temperature at which the resin material is baked. At the same time, the elastic body is maintained at a temperature lower than the resin dispersion to form the resin layer on the elastic body.

Further, the elastic rotating body for fixing of the present invention, an elastic body which is formed so as to previously contain a surfactant on the surface, and a resin dispersion prepared by mixing an unbaked resin material on the elastic body is applied,
And a resin layer formed on the elastic body while maintaining the elastic body at a temperature lower than the resin dispersion while heating the resin dispersion to a high temperature at which the resin material is fired. It is a thing.

(Embodiment) FIG. 1 is an illustration of an embodiment of a fixing device of the present invention having a fixing roller which is an elastic rotating member 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 has a relatively thin silicon rubber (in this example, 0.3 mm to 0.8 mm) on a cored bar 11 having good heat conduction such as aluminum.
(a predetermined thickness within a range of mm) and an elastic layer 12 having a repulsion elastic modulus of 65% to 85%, and a PFA resin (tetrafluoroethylene resin;
Perfluoroalkoxy ethylene resin copolymer), PTFE
A fluorine resin such as (tetrafluoroethylene resin) is thinner than the elastic layer 12 (in this example, a predetermined thickness within the range of 10 μm to 25 μm) and has a resin strength of 50 kg / cm ² or more. Similarly, the pressure roller 2 is relatively thicker than the silicon rubber elastic body layer 12 on the cored bar 21 made of stainless steel, iron or the like (in this example,
Thickness of 4mm to 10mm), its impact resilience is 65%
Approximately 85% of the elastic layer 22 and a fluorine resin such as PFA or PTFE on the elastic layer 22 are thinner than the thick elastic layer 22 (5 μm in this example).
To a predetermined thickness within the 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 the purpose thereof.
Briefly, it includes the following steps.

A silicone rubber layer vulcanized and molded on the core metal (heat conductivity 1.
4 × 10 ^{−4 to} 1.5 × 10 ⁻³ cal · cm / sec · cm ² · ° C.) to form a silicone rubber roller having a desired shape. A preferred shape is an inverted crown type in which the central portion has a slightly smaller diameter than both ends. On this rubber roller surface, unfired fluororesin such as dispersion (a fluororesin powder dispersed in water with a surfactant), enamel or powdered fluororesin is sprayed or electrostatically coated over the entire length of the rubber roller. Apply it to a uniform thickness by a method such as powder coating. The display screen is heated to a glass transition point of 327 ° C. or higher of the crystalline melting point of the fluororesin to form a film-shaped resin film. Therefore, the silicon rubber roller coated with the unsintered fluorine resin needs to be heated to the crystal melting point or higher (PTFE 327 ° C or higher, PFA 306 ° C or higher).

However, although silicon rubber itself has excellent rubber properties such as impact resilience and compression set, it is more than 300 ° C, much less 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, the overheating of the rubber layer loses the function of the rubber layer and the characteristics of the resin layer, and the condition suitable for fixing is 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.

By this method, a thermal gradient is substantially formed in the silicon rubber in the thickness direction thereof, but the temperature of about 260 ° C to 280 ° C is higher than that of the crystalline melting point of the unbaked fluororesin (specifically, Is PTFE and has a firing temperature of 327 ° C or higher of 340 ° C to 380 ° C of 5
It is given for about 10 minutes. After performing this firing, the roller is quenched. By this quenching, the crystallinity on the silicon rubber roller is 95% or less and the tensile strength is 50 kg / cm ² or more,
A baked fluororesin surface layer showing a resin characteristic of a contact angle with water of 100 degrees or more is formed in a strongly adhered state to a rubber roller and is sufficiently thick.

Accordingly, 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 is formed, and the surface fluororesin layer exhibits completely baked resin characteristics. The adhesion of these layers is strong.

Now, 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 always the optimum temperature (at which the toner can be 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 known 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 to 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 sufficient impact resilience because they are completely non-existent in the past, that is, the characteristics of the silicon rubber are not thermally deteriorated and the fluororesin 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,
The adhesion between them is also good.

As shown in FIG. 2, another characteristic configuration of the above configuration is that the elastic layer 12 of the fixing roller has a thickness t ₁ , the resin layer 13 of the fixing roller has a thickness t ₂ , the elastic layer 22 of the pressure roller has a thickness t _3. , And the thickness t ₄ of the resin layer 23 of the pressure roller are as follows.

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 improves each other's defects and complements each other's advantages, resulting in excellent image quality and fixability, and excellent durability.

By the way, it is the film strength of the fluororesin layer and the adhesion between the fluororesin and the silicone rubber layer that have the greatest influence on the durability of the fixing roller having the above-mentioned characteristics. In order to strengthen the adhesive force between the resin and the rubber layer, it is important that the unbaked fluororesin is evenly and sufficiently wet on the rubber layer, and the inventors of the present invention have found means for that.

That is, when PTFE is applied to a silicone rubber having a small surface energy, for example, it is impossible to form a uniform and strong coating film because it repels the dispersion of PTFE. However, the present inventor
Make sure that the surfactant is present on the surface layer of the elastic body by wetting a silicone type surfactant into the silicone rubber or by rubbing the surface layer with a surfactant after the elastic body layer is completed. As a result, we succeeded in improving the wettability of the fluorocarbon resin dispersion, and further improving the adhesion with the elastic layer.

For example, when the polyether modified silicone oil is mixed into the rubber comparand at the time of forming the silicone rubber layer and vulcanization molding is performed, the surfactant is exposed on the surface layer. Therefore, a uniform fluorine resin dispersion layer is formed on the silicone rubber layer with a good affinity for the surfactant contained in the fluorine resin dispersion. When heated during baking, the surfactant flows out from the inside of the silicone rubber to the outside of the roller, creating voids, and conversely, the fluorocarbon resin dispersion penetrates into the voids. Therefore, the adhesive force between the silicone rubber layer and the fluororesin layer is further strengthened.

Also, the same polyether-modified silicone is applied to the silicone rubber surface.
Use a surfactant such as corn oil to blanc or scoop
Itchbright Rub with a scrubbing brush like (product name)
Good. In this case, the silicone rubber surface layer may have small scratches.
A surface active agent was applied to the surface layer due to the stickiness
Fluorine resin has a better affinity with display sponge and evenness
It becomes possible to form a coating film. Then bake this
The same as when a surfactant is mixed into the rubber.
In addition, the fluororesin sufficiently enters the fine irregularities on the rubber surface.
Since it collapses, a strong adhesion can be obtained.

Next, FIG. 3 shows a firing method of the fixing roller. 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, and includes a magnetron 105, a waveguide 106 for transmitting a high frequency (950 MHz to 2450 MHz) generated from the magnetron 105, and a waveguide. An openable and closable resin container 102 having a metallic high-frequency reflector 103 connected to the pipe,
Infrared lamp 111 for infrared external heating, two each at the top and bottom
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.
Arms 107 for fixing the flange 1A of the roller 1 are fixed to the lower part 09, respectively.

110 is a control means of the device, which is a drive means 104 and a magnetron 10
5 and the operation of the infrared lamp 111 are performed by a variable timer (not shown) for a predetermined time depending on the closed state of the container and the input of 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 heating with a high frequency wave, an infrared ray and 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. As a result, the roller characteristics described above can be obtained.

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

When the thickness of the resin layer in the present invention is 10 μ or more, the durability is 25
It can be improved to more than 10,000 sheets, and if it is 15μ or more, durability of 300,000 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 that it decreases with the increase of its thickness. A high degree of fixability can be maintained. The present invention is particularly effective when a fluororesin is provided on the silicone rubber layer.

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 it has the releasability and elasticity of the fluororesin, it has the transferability and the cleaning property (however, the cleaning roller performs cleaning according to the order of surface energy, etc.). It evenly coats the release agent and prevents transfer unevenness, and exerts the advantages of excellent abrasion resistance in each application.

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.

The effect of using the elastic rotating body of the present invention as a fixing roller is that it is excellent in wear resistance and surface releasability, and the surface characteristics of the resin layer and the elastic characteristics of the rubber are sufficiently exerted to obtain toner images and It has an excellent effect of following other rollers and has a very long life.

(Effects of the Invention) As described above, according to the present invention, the adhesive force between the elastic layer and the resin layer can be improved, and an elastic rotating body having more excellent durability can be obtained.

[Brief description of drawings]

FIG. 1 is an explanatory view of an example of a fixing roller (including a belt-shaped roller) and a fixing device having the fixing roller according to an embodiment of the present invention, and FIG. 2 is a partially enlarged explanatory view of the fixing roller, FIG. FIG. 4 is an explanatory view of an embodiment of a method for manufacturing a fixing roller. 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) Masaaki Sakurai 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Masahiro Goto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon (72) Inventor Inichiro Yamamoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Isamu Sakane 5-13-13 Ichiriyama, Otsu City, Shiga Prefecture Inside S-T

Claims (2)

[Claims] 1. A manufacturing method for manufacturing a fixing elastic rotating body having a resin layer on an elastic body, wherein a surface of the elastic body contains a surfactant in advance, and an unbaked resin material is formed on the elastic body. Is applied to the resin dispersion, and then the resin dispersion is heated to a high temperature at which the resin material is fired and the elastic body is maintained at a temperature lower than this resin dispersion to form a resin layer on the elastic body. A method of manufacturing an elastic rotating body for fixing, comprising: 2. An elastic body having a surface-active agent preliminarily formed on the surface thereof, and a resin dispersion prepared by mixing an unfired resin material on the elastic body, and then applying the resin dispersion to the resin material. An elastic rotating body for fixing, comprising: a resin layer formed on the elastic body while maintaining the elastic body at a temperature lower than the resin dispersion while being heated to a high temperature for firing.