JPS647669B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a fixing device in which a toner image support material is closely conveyed to a heat fixing roller to heat and melt and fix the toner.

In order to reliably separate the toner image support material from the heating fixing roller, a claw-like hard separating member is usually brought into contact with this roller. However, on the other hand, the toner is fused to the surface of the separation claw that contacts the toner image support material, but the separation claw that is in contact with the heating fixing roller is hot enough to soften the toner, so the toner cannot be separated. The next toner image support material gets stuck on the toner that has softened and become sticky on the nail.
Jams are likely to occur. Therefore, it was necessary to frequently clean the separation claw. However, once the toner has fused to the separation claw, it adheres to the separation claw so firmly that it is very difficult to clean, causing a jam.

On the other hand, if the separating claw is made of tetrafluoroethylene resin with good mold releasability, it is possible to prevent the above-mentioned toner from adhering to it and therefore prevent the occurrence of jams, but tetrafluoroethylene resin has low strength and Therefore, during use, the tip of the claw that came into contact with the roller became deformed, which caused the jam.

It is also conceivable to construct the separating claw base with a hard heat-resistant resin such as polyimide, and to bake tetrafluoroethylene resin on the toner image support material guiding surface side.
The baking temperature of tetrafluoroethylene resin is as high as 380°C, and no matter how heat-resistant the resin is, thermal deformation frequently occurs at such high temperatures, so when it is incorporated into a fixing device, it may not achieve the desired performance. It is difficult to achieve this, and jams are more likely to occur.

Therefore, it is conceivable to configure a metal such as aluminum as the separating claw base and to bake tetrafluoroethylene resin on the toner image support material guide surface side, but in that case, the claws will not be deformed by the baking temperature. However, it is difficult to uniformly coat the wedge-shaped sharp edge of the tip of the separating claw that contacts the fixing roller, and the background is exposed.If the base is a metal such as aluminum, the toner tends to stick to it. This causes a jam to occur.

Therefore, the main object of the present invention is to solve the above-mentioned disadvantages. To achieve this object, the present invention provides a fixing device having a heating roller to which a toner image supporting material is closely conveyed for image fixing, and a separating member for separating the toner image supporting material from the heating roller. A fixing device characterized in that the member is formed by baking a film made of a mixture of a fluorocarbon resin and a sintering and binding auxiliary resin on at least the toner image support material guide surface side of a hard heat-resistant resin base material, and
In a separating member for separating the toner image support material from the heating roller, a film made of a mixture of a fluorocarbon resin and a baking and fixing auxiliary resin is baked on at least the toner image support material guide surface side of the hard heat-resistant resin base material. This is a separation member characterized by: Embodiments of the present invention will be described below with reference to the drawings.

In the figure, reference numeral 1 denotes a fixing roller in which a hollow cylinder 2 made of a material with good thermal conductivity such as aluminum or copper is thinly coated with a releasable material 3 such as silicone rubber or tetrafluoroethylene resin. 4 is a heating roller having a core metal 5 coated with relatively thick silicone rubber 6. Both rollers 1 and 4 are pressed against each other and rotated in the direction of the arrow. The fixing roller 1 is heated by a heat source 7 such as a halogen lamp disposed inside the fixing roller 1.
heated by. The paper P supporting the unfixed toner image T is guided by the guide plate 9 and enters the pressure contact portion of the rollers 1 and 4, and as the rollers 1 and 4 convey the paper P under pressure, the toner image T is heated to the paper P. Melted and fixed. At this time, the supporting surface of the image T of the paper P comes into close contact with the roller 1, but has a tendency to stick to the roller 1 due to the adhesiveness of the melted toner. So this paper P
In order to reliably separate the roller 1 from the roller 1, a separating claw 16 having a wedge-shaped tip is brought into contact with the roller 1 at a position downstream of the pressure contact portion of the rollers 1 and 4 with respect to the rotating direction of the roller 1. , the paper P stuck to the roller 1 is peeled off. Note that the separation claw 16 is rotatably attached to the shaft 17,
The tip of the claw is brought into elastic contact with the roller 1 by a spring 18.

In addition, 10 is a liquid tank for storing an offset prevention liquid (mold release liquid) 11 such as dimethyl silicone oil, methyl phenyl silicone oil, fluorosilicone oil, etc.
is supplied to the coating roller 15 by capillary action. The roller 15 contacts the fixing roller 1 and rotates in the direction of the arrow, thereby transferring the release liquid to the roller 1.
Apply to the surrounding surface. It is known that by this application, the offset of the toner with respect to the roller 1 and the tendency of the paper P to wrap can be further reduced.

Conventionally, the claw 16 is made of heat-resistant resin such as polyimide, but in this case, as described above, the guide surface 16A of the claw 16 is in sliding contact with the toner image surface of the paper P.
The molten toner adhered to the paper, causing jams. In addition, the release liquid applied to the roller 1 was scraped off by the tip of the claw 16 and spread widely on the guide surface 16A, which caused liquid stains on the paper P.

Therefore, in the present invention, the base of the separation claw 16 is made of a hard heat-resistant resin such as polyimide, and the separation claw 16 is made of a hard heat-resistant resin such as polyimide.
By baking a coating made of a mixture of a fluororesin, which is a mold release resin such as tetrafluoroethylene resin, and another resin, such as an epoxy resin, as a sintering and binding aid on the paper guide surface 16A of No. 6, the jam is formed. This prevents the occurrence of oil stains and oil stains on paper.

An experimental example will be described below. Experiment 1 was about a conventional device, Experiments 2 and 3 were attempts to coat the separating claw guide surface 16A of the conventional device with tetrafluoroethylene resin, and Experiment 4 was about using aluminum as the separating claw base. I tried it. Experiments 5 and 6
This is an example of the present invention. In each experiment, a separation claw 16 having a contact width of 2 mm and a contact pressure of 30 g to the roller 1 was used, and the surface temperature of the fixing roller was maintained at 170°C. As an offset prevention liquid, dimethyl silicone oil having a viscosity of 100 CS at room temperature was applied onto the fixing roller 1 at a consumption rate of 3 x 10 ^-3 g per sheet of A3 size paper.

(Experiment 1) When polyimide separation claws were used as separation claws made of hard heat-resistant resin.

After passing 100 sheets of B4 size paper, when A3 size paper was passed, oil stains appeared on the leading edge of the A3 size paper due to the separation claw corresponding to the area where B4 size paper was not passed.

The oil stains did not disappear even after passing 10 sheets of A3 size paper, the size of the first sheet was 6 mm x 4.5 mm, and the size of the 10th sheet was 3.
It was mm x 2.5 mm.

Next, make the tip 30mm a solid toner image.
When passing A3 size paper, a jam occurred in the fuser after approximately 85,000 sheets.

This is due to the toner being fused to the paper guide surface of the polyimide nail.

(Experiment 2) Using the polyimide nails used in Experiment 1 as the base material for the separation nails, sandblast the entire surface of the base material, including the paper guide surface, and then spray ethylene tetrafluoride coating liquid to a thickness of 25μ over the entire surface of the separation nails. After pre-drying, it was baked at 380°C for 15 minutes. The separation claw was thermally deformed by the baking heat at this time, making it unusable.

(Experiment 3) After applying the same coating as in Experiment 2, 280
Baking was performed at ℃ for 45 minutes. Although the separation claws were not thermally deformed during baking, the adhesion between the tetrafluoroethylene coating and the base material was poor, making them unusable.

(Experiment 4) Aluminum was used as the base material of the separating claw, and after sandblasting and degreasing the entire surface including the paper guide surface,
Apply fluorinated ethylene coating liquid to the entire surface of the separating claw.
Spray coat to a thickness of 25μ, pre-dry, and heat at 380℃.
I baked it for 30 minutes.

When using this separation claw, when passing 100 sheets of B4 size paper and A3 size paper, the size of the oil stain on the leading edge of the paper in the area where B4 paper is not passed is 2 mm x 1.5 from the first sheet. mm, 1.5mm×1mm, 1mm×1mm, 1mm×
At 0.5mm, there were almost no images after the 5th one. Good results were obtained regarding oil stains, but next,
When paper was fed in the same way as in Experiment 1, jams frequently occurred before reaching 5,000 sheets. This is because the sharp tip of the separating claw that comes into contact with the fixing roller cannot be completely coated, and since the base material is aluminum, the release property at the tip of the separating claw is not good. be.

(Experiment 5) After sandblasting the entire surface of the polyimide separating claw used in Experiment 1, the polyimide separation nails used in Experiment 1 were mixed at a ratio of 70:30 (weight ratio) to 4-fluoroethylene resin: epoxy resin, and the 4-fluoroethylene particles were used as a binder resin. Spray coating liquid suspended in epoxy resin to a thickness of 25μ over the entire surface including the paper guide surface, and after pre-drying.
Baking was performed at 180°C for 30 minutes. No thermal deformation occurred during baking. When using this separation claw, when passing 100 sheets of B4 size paper and then passing A3 size paper, the size of the oil stain on the leading edge of the paper is 1 mm at the first sheet in the area where B4 paper is not passed. ×0.5mm

There were hardly any after the second one.

Next, when paper was fed in the same manner as in Experiment 1, no jamming occurred even after 150,000 sheets were fed.

Almost no toner adhered to the separation claw.

(Experiment 6) Polyphenylene sulfide, a hard heat-resistant resin, was used as the base material for the separation claw, and after sandblasting the entire surface of the base material, ethylene tetrafluoride resin: polyphenylene sulfide resin = 60:40 (weight ratio) A coating liquid in which tetrafluoroethylene particles are suspended in polyphenylene sulfide resin as a binder resin is sprayed to a thickness of 25μ over the entire surface of the separation nail, including the paper guide surface, and after pre-drying. at 280℃
I baked it for 30 minutes. At this time, the separation claw was not deformed by heat. When using this separation claw, B4 size paper
After passing 100 sheets, the size of the oil stain on the leading edge of the paper when A3 size paper is passed is as follows:
The first one was 0.5mm x 0.5mm, and the second and subsequent ones were almost non-existent.

Next, when paper was fed in the same manner as in Experiment 1, no jamming occurred even after 150,000 sheets were fed.

There was almost no toner adhesion to the separation claw.

In addition to the above-mentioned polyimide and polyphenylene sulfide, polyamide, polyamideimide, silicone resin, phenol resin, etc. can be used as the hard heat-resistant resin serving as the base of the separation member.

In addition to the above-mentioned epoxy resin and polyphenylene sulfide, phenol resin and the like can be used as the baking aid resin to be mixed with the tetrafluoroethylene resin.

In addition, the mixing ratio (weight ratio) of the baking aid resin to the tetrafluoroethylene resin is
Preferably, it is between 10 and 200 per 100. Ten
If the baking temperature is lower than the heat deformation temperature of the base material, sufficient adhesion strength with the base material cannot be obtained, resulting in poor durability, and insufficient baking results in poor mold release. I can't even get sex.

Moreover, if it is 200 or more, good mold releasability and heat resistance cannot be obtained. In addition to tetrafluoroethylene resin, F (fluorine) is used as a non-adhesive resin.
Trifluoroethylene resin substituted with (chlorine) or the like can also be used, but it is inferior to tetrafluoroethylene resin in non-adhesion.

In any case, according to the present invention, the releasable coating can be formed by baking within the heat deformation temperature and time of the separation member base made of hard heat-resistant resin. A fixing device can be obtained.

[Brief explanation of drawings]

The figure is an explanatory diagram of an embodiment of the present invention, and 1 is a fixing roller, 4 is a pressure roller, 15 is a coating roller, 1
6 is a separation claw, and 16A is a paper guide surface.

Claims (1)

[Scope of Claims] 1. A fixing device including a heating roller on which a toner image supporting material is closely conveyed for image fixing, and a separating member for separating the toner image supporting material from the heating roller, the separating member comprising: A fixing device characterized in that a film made of a mixture of a fluorocarbon resin and a sintering and binding auxiliary resin is baked on at least the toner image support material guide surface side of a hard heat-resistant resin base material. 2. The fixing device according to claim 1, wherein the sintering and binding assisting resin is an epoxy resin, polyphenylene sulfide, or phenolic resin. 3. The fixing device according to claim 1 or 2, wherein the hard heat-resistant resin is polyimide, polyphenylene sulfide, polyamide, polyamideimide, silica resin, or phenolic resin. 4. The fixing device according to any one of claims 1 to 3, wherein the fluororesin is a tetrafluoroethylene resin. 5. In the separation member for separating the toner image support material from the heating roller, a film made of a mixture of fluorocarbon resin and sintering and binding auxiliary resin is baked on at least the toner image support material guide surface side of the hard heat-resistant resin base material. A separation member characterized by: 6. The separation member according to claim 5, wherein the sintering and binding assisting resin is an epoxy resin, polyphenylene sulfide, or phenolic resin. 7. The separation member according to claim 5 or 6, wherein the hard heat-resistant resin is polyimide, polyphenylene sulfide, polyamide, polyamideimide, silica resin, or phenolic resin. 8. The separation member according to claims 5 to 7, wherein the fluororesin is a tetrafluoroethylene resin.