JPH0698707B2 - Glossing belt - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a glossing belt forming a part of a heat fixing device used in an image forming apparatus.

(B) Conventional Technology An image forming apparatus such as a copying machine is provided with a heat fixing device for fixing a formed image and for providing high gloss. In general, a heat fixing device uses a heat roller composed of an upper roller having a heater therein and a lower roller that comes into pressure contact with the upper roller. However, when heat fixing is performed using such a heat roller, the thermoplastic resin may adhere to the upper roller to cause offset, which necessitates a roller cleaning device and increases the size of the heat fixing device. There is a drawback that

Therefore, the present inventors proposed in Japanese Patent Application No. 62-192132 a heating and fixing device in which a glossing belt is stretched between rollers. According to this apparatus, the paper is heated and pressed in a state of being in contact with the glossing belt, is cooled while being fed along the glossing belt, and is then separated from the glossing belt, so that the occurrence of offset can be prevented.

(C) Problems to be Solved by the Invention Conventionally, heat-resistant fluororesin, polyimide resin, and the like have been used as the material of the glossing belt. However, when the glossing belt is made of a fluororesin, the glossing belt may be fatigued by heat and pressure, and wavy permanent strain may occur along the belt conveying direction. The wavy distortion affects the formed image, resulting in a striped pattern in the image, resulting in poor quality. Also, when the glossing belt is made of polyimide resin, the polyimide resin itself has a poor releasability, so when the paper (developer containing the thermoplastic resin) leaves the glossing belt, it produces a strange sound called "burr". There was a problem.

The gloss belt is made of resin, stainless steel,
Although it may be made of metal such as nickel steel,
In that case, there is a problem that the edge of the belt may be injured during jamming or production, which is inconvenient to handle.

In view of the above problems, the object of the present invention is easy to handle,
It is to provide a glossing belt that does not cause deterioration of image quality and abnormal noise.

(D) Means for Solving the Problem The present invention is a glossing belt that is stretched between rollers to smooth the surface of a developer, in which a base sheet made of a polyimide resin is provided with fluororubber and tetrafluoroethylene. It is characterized in that it is coated with a hexafluoropropylene copolymer or a tetrafluoroethylene hexafluoropolypropylene copolymer.

(E) Action In the present invention, fluororubber and tetrafluoroethylene hexafluoropropylene copolymer (hereinafter referred to as FLC),
Alternatively, the release property of the polyimide resin is improved by the tetrafluoroethylene hexafluoropolypropylene copolymer (hereinafter referred to as FEP), so that the abnormal noise of "burr" at the time of paper separation is not generated. Moreover, since the polyimide resin has very good heat resistance, no wavy distortion or the like occurs even after long-term use, and it is easy to handle.

(F) Example FIG. 2 is a schematic front view of a copying machine to which the heat fixing device using the glossing belt of the present invention is applied. In the examples, an example of a copying machine that forms an image using a light-receiving sheet and an image-receiving sheet is shown, but a similar heating and fixing device can be used in a copying machine that forms an image using a photoconductive photoconductor. Used. In this embodiment, the developer is a colorless dye, a developing material and a thermoplastic resin, and the developer in the image forming apparatus using the photoconductor is toner.

A pressure roller 1 is provided inside the copying machine body, and a media cartridge 2 is provided on the left side thereof. The pressure roller 1 is brought into pressure contact with a high pressure of about 90 kg / cm to destroy uncured microcapsules described later. The pressure roller 1
The point where the pressure contacts is the pressure transfer portion P2. The media cartridge 2 is removable from the main body of the copying machine and has a supply shaft 21 and a take-up shaft 22 in the vertical direction in the figure. A light receiving sheet 23 is wound around the supply shaft 21, and the light receiving sheet 23 is exposed.
It is wound around the winding shaft 22 via P1 and the pressure transfer portion P2. The reflected light of the original is guided to the exposure section P1 by the optical system 3 on the upper part of the copying machine, and the light receiving sheet 23 is exposed to the reflected light of the original.

The light receiving sheet 23 is a sheet of polyester or the like coated with microcapsules. The microcapsule is a resin shell in which a photo-curing material and a colorless dye are encapsulated. When exposed to reflected light of a document, the microcapsule exposed to the light cures to form a selectively cured image as a whole.

A paper feed unit 4 including a paper cassette 4a is provided on the right side of the main body of the copying machine. An image receiving sheet is stored in the paper cassette 4a. The image receiving sheet has a surface coated with a thermoplastic resin and a developing material, and is superposed on the selectively cured image of the light receiving sheet 23 and pressed at the pressure transfer portion P2. This destroys the uncured microcapsules,
The encapsulated colorless dye flows out and develops color by the developing material, and a colored image is formed on the image receiving sheet.

A heat fixing device 5 using the glossing belt according to the present invention is arranged on the left side of the copying machine body. Heat fixing device 5
Has a heating roller 51, a separation roller 52, a glossing belt 53, a pressure roller 54, and a fan 55. Heating roller 51
Has a heater such as a halogen lamp inside, and the surface temperature is maintained at a hundred and several tens of degrees. The surface temperature is a temperature at which the thermoplastic resin of the image receiving sheet becomes softened or melted. The separation roller 52 is a roller having a smaller diameter than the heating roller 51, and the glossing belt 53 is stretched between the separation roller 52 and the heating roller 51.

FIG. 1A is a sectional view of the glossing belt 53.

The glossing belt 53 includes a polyimide film 53a and a primer 5
It is composed of 3 layers of 3b and FCL53c. Glossing belt
53 is a polyimide film 53a having a thickness of about 20 to 30 μm, coated with a primer 53b made of, for example, an epoxy adhesive, and then coated with FCL53c for about 20 to 30 μm, and baked and vulcanized at about 270 ° C. .

The glossing belt 53 formed in this way is stretched between the heating roller 51 and the separation roller 52 with the FCL 53c surface facing outward. The pressure roller 54 is pressed against the heating roller 51 via the glossing belt 53. This pressure contact position is the heating portion P3. In addition, the separating roller 52 part includes the glossing belt 53 and the fan 55.
Is cooled by.

The image-receiving sheet on which the color-developed image is formed at the pressure transfer portion P2 is conveyed to the heat fixing device 5, and after passing through the heating portion P3, the glossing belt.
Sent along 53. In the heating part P3, the thermoplastic resin on the image receiving sheet becomes softened or melted to cover the surface of the color image. Further, at this time, pressure is applied simultaneously with heating to smooth the thermoplastic resin. After that, the image receiving sheet is sent along the glossing belt 53 in the direction of arrow A, and is separated from the heating roller 51, so that the thermoplastic resin is gradually cooled. This cooling is promoted by the fan 55, and the thermoplastic resin is almost solidified at the position of the separation roller 52. Then, the image receiving sheet is separated from the glossing belt 53 by the force of the separating roller 52 to wind the glossing belt 53 upward, and is discharged to the discharge tray 7 by the discharge roller 6. When the image-receiving sheet is separated from the glossing belt 53, the FL on the surface of the glossing belt 53
Since the C53c layer is formed, the releasability is improved, and the image receiving sheet can be easily separated without the occurrence of abnormal noise such as "burr".

Incidentally, FIG. 1 (B) is a sectional view showing another embodiment of the glossing belt. The polyimide film 53a 'and the primer 53 are shown in FIG.
It consists of three layers, b'and FEP53d. The polyimide film 53a 'and the primer 53b' are the same as those in FIG. 9A, and FEP 53d is used as the uppermost layer. In this case as well, a glossing belt material can be obtained by baking and vulcanizing at about 270 ° C., and the releasability of the polyimide film 53a ′ can be improved.

(G) Effect of the Invention According to the glossing belt of the present invention, the mold releasability of the polyimide resin can be improved by FCL or FEP.
The thermoplastic resin (developer) can be easily separated without the generation of a "burr" noise. Further, since the polyimide resin having extremely high heat resistance is used as the base sheet, wavy distortion or the like does not occur in the glossing belt even after long-term use, and a high quality image can be formed. Further, since it is made of resin, it is easy to handle and does not get injured at the edge during jamming or production.

[Brief description of drawings]

FIG. 1 (A) is a cross-sectional view of a glossing belt according to an embodiment of the present invention, FIG. 1 (B) is a cross-sectional view of a glossing belt of another embodiment, and FIG. 2 is heating using the glossing belt. It is a front view of a copying machine to which a fixing device is applied. 5 ... Heat fixing device, 51 ... Heating roller, 52 ... Separation roller, 53 ... Glossing belt, 53a, 53a '... Polyimide film, 53b, 53b' ... Primer, 53c ... Fluorine rubber, 4 Fluorinated ethylene hexafluoride propylene (FCL), 53d …… tetrafluoroethylene hexafluoride propylene (FEP).

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display area C08L 79:08

Claims (1)

[Claims] 1. A glossing belt stretched between rollers to smooth the surface of a developer, comprising a base sheet made of a polyimide resin, fluororubber and tetrafluoroethylene hexafluoropropylene copolymer, or A glossing belt characterized by being coated with a tetrafluoroethylene / hexafluoropolypropylene copolymer.