JPH0273279A - Fixing and pressurizing belt - Google Patents

Abstract

PURPOSE:To easily produce the fixing and pressurizing belt at a low cost and to obviate interlayer exfoliation by forming a fluoroplastic layer on the surface of the belt and forming conductive carbon on the inner side of the fluoroplastic layer. CONSTITUTION:The fluoroplastic 2 is formed on the outside surface of a base resin 1 and the conductive carbon layer is formed on the inner side thereof. The fluoroplastic powder having 5 to 10mum average grain size is used and the conductive carbon having 10 to 50mum average grain size is used. The production of the fixing and pressurizing belt is executed by dissolving the base resin in a volatile solvent, mixing the fluoroplastic powder and the conductive carbon therewith, injecting the resin mixture into a cylindrical mold and centrifugally molding the resin mixture under heating. The molding is removed from the mold while the base resin is held half-cured in this centrifugal molding; thereafter, the mold removed from the mold is put on an iron core and is subjected to normal vulcanization. A high antistatic effect is obtd. and the removability of toners is improved in this way.

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to an electrophotographic fusuma copying machine and a facsimile machine.

The present invention relates to a fixing/pressure belt or sleeve (hereinafter simply referred to as a belt) used in a printer or the like, which fixes an image transferred to an object and conveys the object.

<Prior Art> In electrophotographic copying machines, facsimile machines, printers, etc., for example, as shown in FIG.
An electrostatic image is formed on the image forming section 12.
After developing it as a toner image and transferring the toner image to a transfer object 14 such as paper by a transfer section 13,
The transferred image on the transferred object 14 is fixed by the fixing section 15 to obtain the transferred object.

As shown in FIG. 5, this conventional fixing unit 15 is conventionally comprised of a pair of heat rolls 16 and a pressure roll 17 made of noricorn rubber, and roll fixing that fixes the transferred material 14 by sandwiching it. It has been adopted.

However, this roll fixing has the problem that the pressing force of the pressure roll 17 is so strong that, for example, fine glands are crushed and the image becomes unclear. Belt fixing is employed, which includes a belt 19 that abuts and covers a portion of the roll 18.

This belt fixing requires a large contact area, so the fixing and
The pressing force of the pressure belt 19 may be low, and is suitable for precise copying or especially for copying large size sheets, such as round AO sheets.

Fixing/pressure belt 19 (,t,
-Generally, millable silicone rubber (HTV) is used as a raw material, molded by extrusion molding, sheet winding molding, etc., and then polished.

Thereafter, the transferred object 1 is placed on the obtained fixing/pressure belt.
A fluorine coating layer is applied to the surface that contacts 4 to improve releasability from toner.

<Problems to be Solved by the Invention> However, manufacturing the fixing/pressure belt 19 with a conventional fluorine coating layer involves a multi-step manufacturing process, which takes time and effort. There is. Another problem is that the coating technique for using the fluorine coating agent is difficult and time-consuming.

Furthermore, there is a problem in that there is a limit to the flex life of the coating between the belt surface and the fluorine coating agent.

In view of these circumstances, the present invention has been developed to provide a fixing and fixing method that can be manufactured simply and at low cost, and that eliminates the fear that the fluororesin layer on the surface will peel off.
The purpose is to provide a pressure belt.

<Means for Solving the Problems> The fixing pressure belt according to the present invention that achieves the above object has the following features:
This fixing/pressure belt is made by centrifugally molding a mixed resin made by dissolving thermosetting liquid silicone rubber in a volatile solvent and mixing fine powder of fluororesin, and fixes the electrostatic image transferred to the transferred object. It is characterized in that a fluororesin layer is formed on its surface, and a mixed resin obtained by dissolving thermosetting liquid silicone rubber in a volatile solvent and mixing fluororesin fine powder and conductive carbon is centrifugally molded. A fixing/pressure belt for fixing an electrostatic image transferred to an object, which has a fluororesin layer on its surface and a conductive carbon layer inside the fluororesin layer. It is characterized by

The fixing/pressure belt according to the present invention is manufactured by utilizing the difference in specific gravity between a base resin made of thermosetting liquid silicone rubber and a fluororesin or a fluororesin and conductive carbon. That is, when a fluororesin is mixed with the base resin, a fluororesin 112 is formed on the outer surface of the base resin 1, as shown in FIG. Furthermore, when a fluororesin and conductive carbon are mixed in the base resin, a fluororesin layer 2 is formed on the outer surface of the base resin 1, and a conductive carbon layer 3 is formed on the inside thereof, as shown in FIG. It is formed.

Here, as a fluororesin fine powder +; t, 300 to 35
Tetrafluoroethylene hexafluoropropylene copolymer (FEP) that melts at 0°C, polyfluoroalkoxyfluoroethylene
In addition to lt (PFA,) W, polytetrafluoroethylene (P
TFE) etc. may be used, and the average particle size thereof is 5 to 10/
It is better to be in the range of J1. Further, as the conductive carbon, one having an average particle size of 10 to 507 jn may be used.

To manufacture such a fixing/pressure belt, first, the base resin is dissolved in a volatile solvent, and fluororesin fine powder,
Conductive carbon may be mixed, the mixed resin may be injected into a cylindrical mold, and centrifugal molding may be performed while heating.

In this centrifugal molding, the base resin is removed from the mold in a semi-vulcanized state, and then the molded belt is placed over the iron core to perform main vulcanization. Here, the cylindrical mold for centrifugal molding is 110 to 1
It is sufficient to maintain the temperature at 30℃, and the main vulcanization temperature is 180 to 200℃.
Do it with In addition, when heat-melting type FEP or PFA is used as the fluorine resin fine powder, the temperature is 300 to 350℃.
When heated to , the fine fluororesin powder on the belt surface is melted and a fluororesin film is formed by IE.

Embodiment Example The present invention will be explained below based on an example.1 As shown in FIG. One end of a rotating shaft 6 provided to be rotated by a motor 15 is inserted through the bottom of the heating jacket 11 into a box-shaped heating jacket 11 whose opening can be closed, and the rotating shaft 16 is rotated by a motor 15. A fixing/pressure belt was manufactured using a centrifugal molding device in which one end of the cylindrical shape [7] was fixed.

Thermosetting liquid liquid rubber (manufactured by I1 Etsu Kagaku, trade name KE)
-1230 g of -1300 is dissolved in 115 g of a volatile solvent such as toluene or kerosene, and this solution is ? average particle size of 5 to 1
2g of 0-tone fluororesin powder (PFA) and average particle size of 5
3 g of 5-tone carbon black powder (manufactured by Lion, trade name: Ketchen Blank) was mixed. Add this mixture to 1000
The mixture was poured into a cylindrical mold 17 having an inner diameter of 67 mm and a length of 400 mm, which was rotating at r4, the atmosphere was heated to 120 to 130 degrees Celsius, and centrifugal molding was performed for 30 minutes. After stopping the rotation, the belt was taken out from the cylindrical mold 17 and heated at 200° C. for 2 hours to complete curing. The resulting belt has a thickness of 2 mm, and has a fluororesin layer with a thickness of 10/j11 formed on the outside, a conductive layer with a thickness of 10 mm made of carbon black powder on the inside, and the inner layer is , it was made of non-conductive silicola rubber.

When this obtained fixing/pressure belt was used as a belt fixing belt in the same manner as before, the antistatic effect was 11: high,
It had good releasability from toner. Further, no abnormalities were observed even after long-term use.

<Effects of the Invention> The fixing/pressure belt of the present invention has a fluororesin layer on the surface, or a fluororesin layer and a conductive carbon layer integrally formed by centrifugal molding, so it can be easily and inexpensively manufactured. The material is manufactured using the same technology, and there is no fear of delamination between the layers.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views of the fixing/pressure belt of the present invention, FIG. 3 is a cross-sectional view of a centrifugal molding device used in an embodiment of the present invention, and FIG. 4 is a schematic diagram of a copying machine. FIG. 5 is an explanatory diagram showing roll fixing, and FIG. 6 is an explanatory diagram showing belt fixing. In the drawings, 1 is a paste resin, 2 is a fluororesin j-1, and 3 is a conductive carbon layer. Patent application Agent: Hokushin Kogyo Co., Ltd.

Claims (3)

[Claims] (1) A mixed resin made by dissolving thermosetting liquid silicone rubber in a volatile solvent and mixing fine fluororesin powder is centrifugally molded, and fixing/pressure is applied to fix the electrostatic image transferred to the transfer object. A fixing/pressure belt characterized in that a fluororesin layer is formed on the surface of the belt. (2) A mixed resin made by dissolving thermosetting liquid silicone rubber in a volatile solvent and mixing fluororesin fine powder and conductive carbon is centrifugally molded to fix the electrostatic image transferred to the transfer object. A fixing/pressure belt, characterized in that a fluororesin layer is formed on the surface of the fixing/pressure belt, and a conductive carbon layer is formed inside the fluororesin layer. (3) The fixing/pressure belt according to claim 1 or 2, wherein the fluororesin layer on the surface is formed by melting fluororesin fine powder.