JPS63264782A - Thermal fixing roller - Google Patents

Abstract

PURPOSE:To improve the mold releasing property of a mold releasable resin layer and to prevent the occurrence of offsets, by burning the surface section of the resin layer so that the section can be thermally distorted and a stabilized surface can be obtained after the resin layer is baked and the surface is polished. CONSTITUTION:This thermal fixing roller is composed of a conductive core material 10, a conductive primer layer 20 formed on the core material, and the mold releasable resin layer 30 formed on the primer layer 20 by baking. The resin layer 30 is burned so that at least its surface section 300 can be thermally distorted and a stabilized surface can be obtained after it is baked and the surface is polished. If the surface of the resin layer 20 is polished after baking and part of the conductive primer layer 20 is exposed, any fuzzy section can be thermally distorted and a stabilized surface can be obtained when the mold releasable resin layer 30 is burned even though the fuzzy section is produced on the surface of the layer 30. Therefore, the mold releasing property of this thermal fixing roller is maintained at a fixed level and, at the same time, the occurrence of offsets which are produced when the mold releasing capacity lowers can be prevented.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a heat fixing roller.

[Prior Art] Conventionally, a heat fixing roller has been used in combination with a pressure roller of a heat fixing device of an electrophotographic copying machine. This heat fixing roller, together with the pressure roller, pinches and conveys the copy paper on which the toner image has been formed in the previous step from both sides, and
FL! The l-no image is heated and pressed onto the copy paper.

As the heating fixing roller, for example, Japanese Patent Application Laid-Open No. 59-831
The fixing roller disclosed in Publication No. 81 includes a conductive core material, a conductive primer layer formed on the conductive core material, and a releasable resin layer baked on the conductive primer layer. It consists of.

According to this conventional heat fixing roller, in order to prevent offset caused by frictional charging that occurs in the release resin layer by removing static electricity, the surface of the release resin layer is ground, and the release property is removed from the conductive primer layer. A portion of the conductive brimer that penetrates into the resin layer is exposed on the surface.

[Problems to be Solved by the Invention] According to the conventional heat fixing roller described above, f5 friction occurs in the release resin layer? 1ift on the releasability side to remove RF electricity
The surface of the layer is ground. Therefore, the surface of the 1llII type resin layer becomes fluffy. This fluffing deteriorates the mold releasability of the heat constant 40-L, and a portion of the toner tends to adhere to the wax during heat fixing, causing offset.

The main object of the present invention is to eliminate fuzz on the surface of a mold release resin layer while maintaining the static elimination performance of the heat fixing roller, improve mold release performance, and prevent offset.

[Means for Solving the Problems] The heat fixing roller of the present invention includes a conductive core material, a conductive primer layer formed on the conductive core material, and a release layer baked on the J4 conductive primer layer. In the heating fixing roller comprising a moldable resin layer, the moldable resin layer is surface-polished after baking, and is further fired to thermally deform at least a surface portion of the moldable resin layer so that the surface becomes a stabilizing surface. That is.

[Operation of the invention] According to the heat fixing roller of the invention, #! If the surface of the J-type VA resin layer is polished after baking to expose a part of the conductive primer layer on the surface, even if fuzz occurs on the surface of the release resin layer, after this When the mold release resin is refired, the fluffed portion is thermally deformed and the surface becomes a stabilizing surface. Therefore, the mold release performance of the heating chamber roller having the mold release resin layer whose surface has been polished is maintained constant, and offset due to deterioration of the mold release performance does not occur.

In addition, the frictional charge generated on the heat fixing roller is transferred from the release resin layer to the conductive primer layer and the conductive core material by the conductive primer exposed on the surface of the polished release resin layer i layer. Conducts electricity and eliminates static electricity.

As a result, the heating fixing roller does not generate offset due to frictional electrification.

[Example] Fig. 1 shows a longitudinal section of a heat fixing roller according to an example of the present invention, Fig. 2 shows an enlarged view of a part of Fig. 1, Fig. 3 shows a side view of an example of use, and heat fixing The surface of the roller will be explained based on FIGS. 4 and 5, which show enlarged electron microscope photographs instead of drawings.

The heat fixing roller 1 of this embodiment is composed of a conductive core material 10, a conductive primer layer 20, and a releasable resin layer 30, as shown in cross section in FIG.

The conductive core material 10 is made of aluminum, aluminum alloy,
Cylindrical latches made of stainless steel, iron alloys, and other metals are used.

The conductive primer layer 20 is formed on the conductive core material 10, and is made of conductive powder such as carbon particles and a binder. Ill with this conductive bamboo powder!
A portion 210 of the conductive primer layer 210 consisting of the adhesive is attached to the outer circumferential surface 200 of the conductive primer layer 20 as shown in FIG.
It permeates into the inside of the releasable resin layer 30 formed above, which will be described later, by capillary action. Therefore, by polishing the surface 300 of the mold release resin layer 30, a portion 210 of the conductive brimer is exposed on the surface 300. A portion 210 of this conductive brimer is made of Ill-type resin I! ! A conductive primer [120
It has the effect of grounding closer to the conductive core material 10 side.

The mold release resin layer 30 is formed by baking on the conductive primer layer 20. Specifically, the outer peripheral surface 200 of the conductive primer layer 20 is electrostatically powder coated with powder of a resin whose main component is a fluororesin or a tetrafluoroethylene-perfluoroalkoxyethylene copolymer.

Thereafter, the electrostatically powder-coated resin powder is fired in a heating furnace (not shown) to form a releasable resin layer 3o baked on the conductive primer layer 20. A temperature of 360° C. or higher is used for the firing.

After the mold release resin layer 30 is baked on the conductive primer layer 20, the surface 300 is polished with a polishing material (not shown) such as a whetstone or a puff, and then baked in a heating furnace (not shown). be done. In this case, the re-firing temperature is 3
Temperatures of 20°C or higher can be used. By this re-firing, the polished surface portion is thermally deformed, and the surface 300 becomes a stabilizing surface.

Note that the thickness of the releasable resin layer 30 is about 30 to 20 μm.

The heat fixing roller 1 configured as described above is used as a heat fixing device Ak in an electrophotographic copying machine as shown in FIG.
It is attached and used in combination with the pressure fixing roller 2. In this case, the heat fixing row 1 includes a heater 10a within the conductive core 10. Also, the heating fixing roller 1
The conductive core material 10 is centered at both ends in the axial direction (not shown).
is rotatably retained in the housing by a conductive shaft coupled to the housing. Therefore, even if frictional charging occurs on the surface 300 of the release resin layer 30 due to the copy paper 4 and the pressure fixing roller 2 that come into contact with the heat fixing roller 1, the part 210 of the conductive brimer and the conductive Primer layer 2
0 to the conductive core material 10 side to eliminate static electricity. As a result, offset due to FJ frictional charging does not occur. Furthermore, mold release resin 11! Even if the surface 300 of J30 is polished, the polished surface of the surface 300 is re-baked and thermally deformed and becomes a stabilizing surface, so it maintains mold release performance and also generates offset due to a decrease in mold release performance. do not.

Furthermore, according to the embodiments of the present invention, as in the experimental examples shown below, it is possible to improve the offset prevention performance and the frictional charge removal performance as compared to the comparative examples.

(Experimental example) Next, the heat fixing roller 1 of the above example was compared with a conventional heat fixing roller, and performance evaluation and release property lifM were performed.
An example of an experiment for confirming the state of the surface 300 of 430 will be shown.

In conducting the experiment, a heat fixing device A in an electrophotographic copying machine as shown in the cross section in FIG.
The heating fixing roller 1 of the embodiment of the present invention and the conventional pressure fixing roller 2 were used in combination in the apparatus aA. Further, in the heat setting 111 mA, there is a conveyance guide 5 that conveys the copy paper 4 on which a toner image has been formed from the previous step, and a conveyance guide 5 that separates the copy paper 4 that has landed on the heat fixing roller 1 and guides it to the conveyance rollers 7 and 8 side. A separation claw 6 that cleans the surface of the heat fixing roller 1, a cleaning device 9 that cleans the surface of the heat fixing roller 1, and the like are provided. Furthermore, as experimental conditions, the diameter of the heat fixing roller 1 and the pressure fixing roller 2 is 24 IIm, and the nip width is 3.811
IIIl, the feed speed of both rollers 1 and 2 is 87 + 111
11/SeG, the contact pressure of both rollers 1 and 2 is 15 kq
And so.

In addition, the experimental results for each material to be tested under these experimental conditions are shown in Table 1, Table 2, and Table 3 below, including paper charging characteristics, offset state, surface state, and surface roughness. It is indicated by degrees. In each table, the charging characteristic value for paper passing is the surface 'i
Measurements were made using a fi-kei (5SVII-40 made by Kawaguchi fff Kisono).The presence or absence of offset was determined by visual inspection of the copy paper.
I approve. A circle mark indicates a case where almost no offset occurred. The Δ mark indicates a case where a slight offset state occurs.

The x and xx marks indicate cases where an offset occurs.

In addition, the surface roughness R Raku Z in Tables 1, 2, and 3 was determined using the JISBO601 measurement method using a universal surface profile measuring device (MODEL 5EP-10 manufactured by Koita Research Institute).
These are the results measured using Δ). The surface condition was confirmed by electron micrograph (magnification: 500 times). In addition, in Figures 4 to 7, ×500 indicates magnification, and 60 μm
indicates the length from the leftmost point to the rightmost point.

Experimental Example 1 The heating fixing roller 1 of this example had a release property of 64
After the surface 300 of the F1 layer 30 was polished, it was refired.

In this case, the re-firing temperature is 320℃, and the re-baking time is 15 minutes to 4
It is 0 minutes. The results are shown in Table 1.

(The following is a blank space) Table 1 Figure 4 shows the surface ril! of this experimental example 1. An electron micrograph shows the surface condition of the heat fixing roller after being refired at a refire temperature of 320° C. after polishing. In this case, the surface is thermally deformed and becomes smooth and granular.

Experimental Example 2, the re-firing temperature of the surface 300 of the releasable a4rB layer 30 of the heat fixing roller 1 is the re-baking temperature 3 of Experimental Example 1 above.
The temperature is 380°C, which is higher than 20°C. The re-firing time is 15 minutes to 40 minutes, which is the same as in Experimental Example 1 above. In this case, the same experimental results as shown in Table 1 were obtained when the re-firing temperature was 320°C. (Description of experimental results is omitted). Further, FIG. 5 shows an electron micrograph showing the surface condition of the heat fixing roller of the present Example 2, which was refired at a refire temperature of 380° C. after surface polishing. In this case, the surface is thermally deformed and becomes smooth and granular.

Experimental Example 3: A comparative experimental example in which the heating fixing roller 1 was polished and then refired at a temperature lower than the refire temperature of 320° C. in Experimental Example 1 is shown below. In this case, the re-firing temperature is 300℃
The firing time was 15 to 40 minutes, the same as in Experimental Example 1. The results are shown in Table 2.

Table 2 and FIG. 6 show electron micrographs of the surface condition of the heat fixing roller after the surface was polished and refired at a refire temperature of 300°C. In this case, the surface is not sufficiently thermally deformed and some fuzz remains due to polishing.

Experimental Example 4: As a conventional example, a heat-fixing O-La was used in which the surface of the releasing resin layer remained polished and was not re-baked. The results are shown in Table 3.

(The following is a blank space.) Table 3 In addition, FIG. 7 shows an electron micrograph of the surface condition of the heating fixing roller in a conventional example in which only surface polishing is performed and no baking is performed. In this case, since the surface is not heat-treated, the fuzz caused by polishing remains as it is.

The above experiment revealed the following points. As shown in Table 3, in the conventional heating fixing roller, the surface roughness RZ of the releasable resin layer appeared as a small value5, and it was found from electron micrographs that the surface was fluffed due to polishing. It can be assumed that toner or paper dust enters this fluffy portion and causes offset.

Furthermore, even if the surface roughness RZ is larger than the values shown in Tables 2 and 3, such as the Ja value shown in Table 1 of the embodiment of the present invention, the releasability of the heat fixing roller is It is assumed that offset does not occur because the surface of the resin layer is re-fired and the surface part is thermally deformed and becomes a stabilizing surface, so that tofu and paper dust etc. do not get into this stabilizing surface. be done.

[Effects] According to the present invention, there is provided a heating fixing roller comprising a conductive core material, a conductive primer layer formed on the conductive core material, and a releasable resin layer baked on the conductive primer layer. After baking, the releasable resin layer has a surface T! + It is polished and then re-fired so that at least the surface part is thermally deformed and the surface becomes a stabilized surface. Therefore, in order to remove the frictional charge generated on the release resin layer of the heating fixing roller, even if the surface of the release resin layer is polished to expose a part of the conductive brimer on the surface of the release resin layer. The mold releasability tree llFm has good mold release performance and no offset occurs. In addition, it is also possible to effectively eliminate charges caused by charging the paper and the pressure fixing roller.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a heat fixing roller according to an embodiment of the present invention. FIG. 2 is an enlarged vertical sectional view of a portion of FIG. 1. FIG. 3 is a sectional view when the heat fixing roller shown in FIG. 1 is incorporated into a heat fixing device in an electrophotographic copying machine. 4 and 5 are enlarged electron microscope photographs (magnification: 500 times) showing, in place of drawings, the state of the particle structure on the surface of the heat fixing roller according to the embodiment of the present invention. FIG. 6 is an enlarged electron microscope photograph (magnification: 500 times) showing the state of the particle structure on the surface of a heating fixing roller as a comparative example of experiments outside the temperature range according to the embodiment of the present invention. FIG. 7 is an enlarged electron microscope photograph (magnification: 500
times). 1... Heat fixing roller 10... Conductive core material 20
... Conductive primer layer 30 ... Release resin layer

Claims (3)

[Claims] (1) In a heat fixing roller comprising a conductive core material, a conductive primer layer formed on the conductive core material, and a release resin layer baked on the conductive primer layer, the release The moldable resin layer is surface-polished after baking, and is further baked to thermally deform at least a portion of the surface of the heat-fixing roller so that the surface becomes a stabilized surface. (2) The heat fixing roller according to claim 1, wherein the releasable resin layer is a fluororesin layer. (3) The release resin layer is a resin layer whose main component is a tetrafluoroethylene-perfluoroalkoxyethylene copolymer, and the firing for stabilization is done at a temperature of 320°C or higher. A heat fixing roller according to claim 1.