JPS5827175A - Fixing roller - Google Patents

Abstract

PURPOSE:To enhance resistance to scratch and abrasion, and nonstickiness, and to extend useful life, by using the fixing roller of an electrostatic copying machine or the like made by laminating a fluororubber or silicone rubber layer, and a layer of a mixture of fluororubber and a fluororesin successively on the outer surface of a metallic roller. CONSTITUTION:A 0.1-3.0mm. thick elastic layer 2 made of fluoreorubber or silicone rubber is formed on the surface of an aluminum or the like metallic roller. A 5-10mum thick layer 3 made of a mixture of fluororubber and 5- 70wt% fluororesin based on the mixture is formed on the layer 2 surface, thus permitting abrasion and scratch due to an edge used for peeling a transfer paper from the fixing roller, or a blade or the like used for cleaning the roller surface to be prevented, and the layer 3 to be prevented from peeling ready to occur when the layer 3 is directly on the metallic roller 1. The layer 3 is nonsticky and causes no offset phenomenon.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fixing roller for electronic copying machines, facsimile machines, and the like.

In electrostatic type electronic copying machines and the like, a heating roller is often used as a method for fixing a toner image formed on a sheet of paper. This fixing method is a method in which the paper on which the toner image has been formed is passed between two rollers pressed together, and one or both of the rollers is heated from the inside to fuse the l.toner image onto the paper.

This fixing method has many advantages over other open fixing methods, such as high thermal efficiency and easy speedup, and it is rarely used in modern electronic copying machines. A fixing method using a roller is used. Usually, the fixing roller is made of a metal such as stainless steel or aluminum and its surface is coated with a non-adhesive substance such as fluorine resin or silicone rubber to prevent offset.

Recently, rollers coated with fluoroplastics such as tetrafluoroethylene resin (hereinafter abbreviated as PTFE resin) or tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (hereinafter abbreviated as PFA resin) have become popular as heat fixing rollers. Used in electronic copying machines.

However, in the case of a heat fixing roller coated with such a fluorocarbon resin, there is a problem that the abrasion resistance or scratch resistance is insufficient.

In other words, the heat fixing roller has a peeling tab to peel the paper off the roller, a blade or felt to clean the roller surface, and a thermistor to detect the roller surface temperature, all of which are in constant contact with the roller. The fluorocarbon resin is abraded or damaged by these, and is also abraded by the L-1 and paper that pass between the support roller and the fixing roller.As a result, after long-term use, the underlying metal is exposed and the fixing There was a problem that the roller could no longer function as a roller.

The present inventor completed the present invention as a result of repeated studies to develop a fixing roller that solves these problems, prevents the coated surface from being damaged, and has a sufficiently non-adhesive surface.

In other words, the feature of the present invention is that an elastic layer such as silicone rubber or fluorocarbon rubber is provided on the outer surface of the metal roller, and a layer made of a mixture of a fluorocarbon resin layer and fluorocarbon rubber is further provided on the surface of the elastic material. It is. This is illustrated in Figure 1.

In FIG. 1, 1 is a metal part such as aluminum or stainless steel, 2 is an elastic layer coated thereon, and 3 is a layer made of a mixture of fluorine resin and fluorine rubber.

The inventors of the present invention have discovered that the above-mentioned problems of the conventional fixing roller can be solved by using a fixing roller having such a cross-sectional structure.

In the case of the roller having the structure of the present invention, the outermost surface of the fixing roller that comes into contact with the toner image is a layer made of a mixture of fluorine resin and fluorine rubber. Excellent mold releasability. Therefore, offset does not occur even if an anti-offset liquid such as silicone oil is not applied.

Further, the problem of a roller coated only with fluorocarbon resin, that the peeling tab is easily damaged, can be solved by using a roller having the structure of the present invention. Furthermore, it is even less likely to be scratched compared to a roller in which a mixture of fluorine resin and fluorine rubber is directly coated on a metal roller without using an elastic layer.

The reason for this is thought to be as follows.

In other words, if a plastic tab is in contact with the fluoroplastic surface under a constant load and the roller is rotated in this condition,
The elastic body deforms through the fluorocarbon resin coated on it, and the fluorocarbon resin layer also deforms along with this elastic body, so the wear of the resin is alleviated, compared to when the metal surface is directly coated with fluorocarbon resin. It is highly effective in preventing scratches.

The reason why it is preferable to cover the elastic layer with a mixture of fluorine resin and fluorine rubber rather than with fluorine resin alone is as follows.
There are two points below.

(1) In the case of using fluorine resin alone, the temperature at which the surface is coated and then fired is 300°G or higher, which causes deterioration of the underlying elastic layer and causes a slight loss of elasticity.

;l On the other hand, in the case of a mixture of fluorocarbon resin and fluorocarbon rubber, since the baking temperature is 250 to 300'O, thermal deterioration of the elastic layer is less.

(2) Regarding adhesion to the elastic body layer, a mixture of a fluorocarbon resin and a fluorocarbon rubber has greater adhesion than a fluorocarbon resin alone.

The present invention will be explained in more detail.

The elastic layer provided on the surface of the metal roller must be made of either silicone rubber or fluorine rubber, or a mixture thereof, taking into consideration the temperature at which the fixing roller is used. This is to increase the adhesion of the interface between the fluorine resin, the fluorine rubber layer, and the layer made of a mixture of the fluorine resin and fluorine rubber on the surface of the elastic layer, and to prevent the interface from exploding. In other words, since fluorocarbon rubber has greater adhesion to fluorocarbon resin than silicone rubber, it is more preferable to use fluorocarbon rubber as the elastic body.

Furthermore, the thickness of this elastic layer is Q, l ran
It is preferable that it is between 3.0 and 3.0.

If Q, lam or less, the effect of mitigating scratches on the surface layer as an elastic body becomes small, and the surface layer becomes easily damaged. Further, if the roller is 3.0111111 or more, there is a problem that heat transfer becomes poor when heating the roller from the inside.

Next, the mixed layer on the surface will be described.

The mixing ratio of fluoro rubber and fluoro resin is 9 in terms of weight ratio.
The ratio is preferably 5:5 to ao:qo.

If the amount of fluorine rubber is less than this, the rubber-like elasticity of the roller coating layer will be lost, and when used as a fixing roller, it will be more likely to be scratched by a peeling nail or the like.

Furthermore, if the amount of fluorine rubber is more than this, the non-adhesiveness will be low and offset will easily occur, causing a practical problem.

Further, the thickness of the layer made of the mixture of fluorocarbon resin and fluorocarbon rubber is preferably 5 μm or more and 100 μm or less.

If the resin thickness exceeds 100 microns, the effect of mitigating wear caused by the elastic layer will be reduced, and if the roller is heated from the inside, there will be problems in that heat transfer will be poor.

Furthermore, if the layer made of a mixture of fluorine resin and fluorine rubber on the surface is less than 5 μm, there is a problem that the resin will wear out with long-term use and the elastic layer will be exposed on the surface, resulting in a decrease in non-adhesiveness.

Therefore, the thickness of the mixture of fluorocarbon resin and fluorocarbon rubber coated on the elastic body is desirably 5 μm or more and 100 μm or less.

The fluorocarbon resin used here needs to have a continuous usable temperature of about 200°G or higher, which is necessary for the fixing roller, so tetrafluoroethylene resin and tetrafluoroethylene-perfluoroalkoxyethylene resin polymer (hereinafter abbreviated as PFA resin), or tetrafluoroethylene-hexafluoropropylene resin (hereinafter abbreviated as FDP resin)
are desirable, and among these, PFA resin is particularly preferred.

Next, examples of the present invention will be described.

Example 1 The surface of an aluminum roller with an outer diameter of 50 rJmψ was roughened by sandblasting, and the surface was coated with fluorocarbon rubber (Daiel G-501 manufactured by Daikin Industries, Ltd.) to a thickness of about 0.5H.

On this side, apply 20% of tetrafluoroethylene resin and fluoro rubber.
A vulcanizing agent was added and mixed to an aqueous dispersion mixed in a ratio of 80%, and this was applied by spraying and air-dried. The coating thickness at this time was 30μ.

This was heated at 800° C. for 15 minutes to produce a heat fixing roller of the present invention.

When this roller was set in the fixing section of a copying machine and the toner image on the paper was fixed at a roller surface temperature of 180 DEG C., no offset occurred.

Next, in order to evaluate the scratch resistance of this roller, a claw (made of polyimide resin) to prevent paper from sticking was brought into contact with the roller at a load of 8002 on the fixing section, and the roller was held for 200 hours at a roller surface temperature of 180°G. Rotated. As a result, the amount of decrease in the resin thickness of the fluorocarbon resin at the contact area of the claw was 1μ.
It was below.

Comparative Example 1 The surface of an aluminum roller with an outer diameter of 50 fiψ was roughened with Sandoplast, and this surface was coated with fluorocarbon rubber (Daiel G-501 manufactured by Daikin Industries, Ltd.) to a thickness of about 0.65 mm, and then processed at 200 g. A roller coated with sulfurized fluorine rubber was obtained.

When this roller was set in the fixing section of a copying machine and the toner image on the paper was fixed at a roller surface temperature of 180°C,
It has become clear that offset occurs and there is a problem in practical use as a fixing roller.

Comparative Example 2 The surface of an aluminum roller with an outer diameter of 5 Q mnψ was roughened by sand blasting, and this surface was coated with a mixed dispersion of tetrafluoroethylene resin and fluoro rubber having the same composition as in Example 1 to a thickness of 30 μm. After drying, heat at 300°G.
I baked it with

When the scratch resistance of this roller was evaluated in the same manner as in Example 1, the amount of decrease in resin thickness at the contact portion of the claw was approximately 5 μm.

As described above, it is clear that directly coating metal with a mixture of fluoro rubber and fluoro resin does not have sufficient effect in preventing scratches.

Example 2 The surface of an aluminum roller having an outer diameter of 50 ψ was roughened by sandblasting. Approximately 1 coat of fluorocarbon rubber is applied to this surface.
It was coated to the thickness of the torso. A mixed dispersion of tetrafluoroethylene resin and fluoro rubber shown in Table 2 was applied to the surface by spraying, dried, and baked at 280°G for 20 minutes.

The thickness of the mixture layer at this time was 30μ.

This roller was evaluated in the same manner as in Example 1.

These results are shown in Table 2 below.

Table 2 Thus, it can be seen that the ratio of fluorine resin and fluorine rubber in the outermost mixed layer is preferably 5:95 to 30 near 0.

As described above in the Examples and Comparative Examples, the present invention is a fixing roller in which an elastic layer is provided on the outer surface of the metal roller, and a mixed layer of fluorocarbon resin and fluorocarbon rubber is further provided on the surface of the elastic material. A roller like this has an excellent non-adhesive surface,
It also has the excellent property of being resistant to scratches on anything that comes into contact with the roller.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the fixing roller of the present invention. ■・・・Metal roller 2...Elastic layer 3...Mixed layer of fluorine resin layer and fluorine rubber 18- Figure 1

Claims (5)

[Claims] (1) An elastic layer made of fluorine rubber or silicone rubber on the outer surface of the Gold X roller, and a fixing roller made of four pieces of this elastic material. (2) The thickness of the elastic layer made of fluoro rubber or silicone rubber is 0.1 fi to 3. The fixing roller according to claim 1, wherein the fixing roller is OM. (3) The mixing ratio of the mixture of fluorocarbon resin and fluorocarbon rubber is
The fluorocarbon resin accounts for 5% to 70% by weight based on the total amount of the fluorocarbon resin and the fluorocarbon rubber, and the thickness of the fluorocarbon resin is 5μ to 70% by weight.
Claim 1 characterized in that the diameter is 100μ.
Section fusing roller. (4) Claim 1, wherein the fluorocarbon resin is a tetrafluoroethylene resin, a tetrafluoroethylene-perfluoroalkoxyethylene copolymer, or a tetrafluoroethylene-hexafluoropropylene copolymer. Section fusing roller. (5) The heating roller according to claim 1, wherein the layer made of a mixture of fluorocarbon resin and fluorocarbon rubber has a structure in which the fluorocarbon resin content is high in the surface layer and low in the interior of the coating layer.