JPH0435932A - Manufacture of thermal fixation roller - Google Patents

Abstract

PURPOSE:To obtain a thermal fixation roller which has high picture quality and is superior in durability by a method wherein at the time of performance of heating and firing by a near infrared irradiation device by coating fluorine resin on a rubber layer provided on a metallic center shaft, an appropriate temperature pattern is stored beforehand as a current value pattern and output of an irradiation device is controlled. CONSTITUTION:Fluorine resin 2 coating a metallic center shaft 4 through a rubber layer 5 is heated and fired selectively by near infrared rays applied to the fluorine resin 2 from the vicinity of the surface. At this time, output of a near infrared irradiation device 1 is based on an electric current value pattern stored beforehand in a memory and, moreover, heat deterioration of the rubber layer 5 is controlled to the minimum and an appropriate temperature pattern, through which favorable firing is performed, is stored as an electric current pattern. Therefore, the fluorine resin is fired favorably and meantime heat deterioration of the rubber layer is controlled to the minimum. Thus, a thermal fixation roller, which is superior in reproducibility, has little deteriora tion also of a rubber layer and is high-function, can be manufactured efficiently and stably.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention relates to a method for manufacturing a heat fixing roller used in a heat fixing section of an electronic copying machine, etc. The present invention relates to a method of manufacturing a heat fixing roller to be used.

(Prior Art) In recent years, there has been a strong demand for higher image quality, lower cost, and longer life for thermal fixing rollers used in thermal fixing units of electronic copying machines, laser beam printers, and the like.

Under these circumstances, as a heat fixing roller that can provide high image quality,
A rubber material such as silicone rubber is coated on a metal shaft such as aluminum, and PFA, which has good releasability from toner, is coated on this rubber layer.
(perfluoroalkoxy resin) or PTFE (polytetrafluoroethylene resin) are known.

In forming the fluorine material □ fat layer, conventional methods include applying a fluororesin paint and baking it, and coating and heat-sealing a fluororesin tube.

However, in the method of applying and firing fluororesin paint, the firing temperature is generally high and temperature control is difficult, so there is a problem that the base rubber layer is exposed to high temperatures during the firing process and is susceptible to thermal deterioration. . Various methods have been devised to deal with this problem, but all of them have the disadvantage of decreasing productivity and increasing costs.

On the other hand, in the method using a fluororesin tube, the thickness is 30
Since it is technically difficult to manufacture tubes with a thickness of less than .mu.m, thicker tubes must be used, resulting in poor thermal response and poor fixing performance.

(Problems to be Solved by the Invention) Conventionally, heat fixing rollers in which a fluororesin layer is provided on a small metal shaft via a rubber layer have been developed as rollers that have good releasability from toner and can provide high image quality. Various manufacturing methods have been developed and studied.

However, there are some drawbacks, such as the rubber layer being easily deteriorated by the heat during fluororesin firing, poor productivity and high costs, and poor thermal response and poor fixing properties. There is no way to stably manufacture a high-performance heat fixing roller at low cost, and the development of such a method is awaited.

The present invention has been made in response to such demands.
The purpose of the present invention is to provide a method for stably manufacturing a high-performance heat fixing roller with high image quality and excellent durability at low cost.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a rubber layer on a small metal shaft, coats a fluororesin on the rubber layer, and then burns the metal coated with the fluororesin. In a method for manufacturing a heat fixing roller in which a core shaft is housed in a heating furnace equipped with a near-infrared ray irradiation device and heated and baked by irradiating near-infrared rays from near the surface thereof, thermal deterioration of the rubber layer is minimized in advance. A suitable temperature pattern for firing that results in good firing is stored in a storage device as a pattern of current values flowing through the near-infrared irradiation device, and the output of the near-infrared irradiation device is controlled based on the stored current value pattern. The method is characterized in that the fluororesin is heated and fired.

Suitable rubber materials for use in the present invention include silicone rubber and fluororubber, which have excellent heat resistance and appropriate elasticity.

Further, as the fluororesin, for example, PTFE.

Examples include PFA and FEP (fluorinated ethylene propylene resin), which is a copolymer of tetrafluoroethylene and perfluoropropylene.

Such fluororesin can be produced by applying fluororesin paint, for example, on a rubber layer formed by coating a small metal shaft such as aluminum with a rubber material such as the one described above, or by statically applying fluororesin powder. It is coated by electrocoating, etc.

Furthermore, as a heating furnace equipped with a near-infrared irradiation device, as shown in FIG. It is preferable to use a roller in which the entire surface of the roller 3 containing the unfired fluororesin coating 2 is irradiated with near-infrared rays uniformly and efficiently.

Note that the absorption band of fluororesin is in the near-infrared region (wavelength approximately 2.5 cm).
5 μm or less), the fluororesin coating 2 on the surface of the roller 3 absorbs the irradiated near-infrared rays and is selectively heated. Therefore, the inner rubber layer 5 is not heated unnecessarily, and thermal deterioration of the rubber is prevented.

(Function) In the present invention, the fluororesin coated on the small metal shaft via the rubber layer is selectively heated and fired by near-infrared rays irradiated from near the surface; The output of the device is based on a current value pattern stored in five memory bags in advance, and this current value pattern is a firing pattern that minimizes thermal deterioration of the rubber layer and achieves good firing. Since the appropriate temperature pattern is stored in the storage device as a current value pattern, the fluororesin can be fired satisfactorily, and thermal deterioration of the rubber layer can be suppressed to a minimum during that time. In addition, the reproducibility is excellent, and a high-performance heat fixing roller in which the fluororesin is baked well and the rubber layer is less likely to be deteriorated by heat can be repeatedly and stably manufactured efficiently.

(Example) Next, embodiments of the present invention will be described using the drawings.

FIG. 1 is a system schematic diagram of the firing apparatus used in this example.

In the figure, reference numeral 6 denotes a heating furnace equipped with a plurality of near-infrared lamps having highly reflective uniform curved surfaces as shown in FIG.
A predetermined electric power is supplied from an AC power source 9 connected to the output unit 8 through the transformer 7 and the output unit 8.

Furthermore, a thermocouple 10 is inserted into the heating furnace 6 to detect the temperature near the metal core axis of the contained roller, and a temperature control device 12 connected to the thermocouple 9 via a sequencer 11 controls the The temperature inside the furnace is controlled. That is, the temperature measured by the thermocouple 10 and the appropriate temperature input in advance are compared, and an output control signal is output to the output unit 8 via the sequencer 11, thereby controlling the temperature of the heating furnace 6. .

The output control signal output from the temperature control device 12 is also output to the data logger 13 via the sequencer 11, where the temperature increase pattern of the furnace temperature is recorded and also stored as a current value pattern. Furthermore, an output control signal based on the stored current value pattern is outputted to the output unit 3 via the sequencer 6, thereby controlling the temperature inside the furnace.

Hereinafter, an example of manufacturing a heat fixing roller according to the present invention using such a baking device will be specifically described.

First, a silicone rubber roller (outer diameter 60a++a
AD-1 (manufactured by Asahi Glass Co., Ltd.) was applied as a PTFE dispersion onto the surface of a 330-inch (body length: 330 mm) by a dipping method and dried to form a PTFE coating film.

Next, this roller is housed in the heating furnace 1 and energized, and the power output is controlled based on the temperature measured by the thermocouple 5, thereby controlling the temperature of the heating furnace 1 and baking the PTFE coating film. At the same time, the data logger 8 recorded the temperature increase pattern of the furnace, and the furnace memorized the current value pattern at that time. After the control, the power output of the heating furnace 1 is controlled based on this memorized current value pattern, and while controlling the temperature of the heating furnace 1, a PTFE coating film is formed on the surface in the same manner as above, and the heating furnace is heated. Reversing the process of baking the PTFE coating film of the roller housed in
0 heat fixing rollers were manufactured.

The heat fixing rollers obtained in this way, namely the heat fixing rollers manufactured while controlling the power output of the heating furnace 1 based on the current value pattern, and the heat fixing rollers obtained by controlling the power output of the heating furnace 1 first by actual measurements with thermocouples. silicone rubber and PTF
The results of measuring the physical properties of the E-fired film are shown in the following table. The physical properties of the silicone rubber are shown as the remaining percentage when the value before firing is taken as 100%.

The physical properties required for the fired PTFE film are also shown in the same table as expected values.

(Hereinafter, blank space) (Hereinafter, blank space) As is clear from the table, in the heat fixing roller obtained according to the present invention, the silicone rubber layer showed very little deterioration due to baking, and the PTFE coating film was also baked well. Furthermore, the reproducibility was excellent, and almost no variation was observed in these physical properties.

The graph shown in FIG. 3 shows the temperature rise curve of the furnace temperature recorded in the data logger 13, where the curve (A) is the one when the current value pattern is first stored, and the curve (
B) shows when the furnace temperature was controlled based on the current value pattern that was subsequently stored. However, there is almost no difference between the two temperature rise curves, indicating that the present invention is a method with excellent reproducibility.

[Effects of the Invention] As is clear from the above explanation, according to the method of the present invention, a near-infrared irradiation device is used to bake the fluororesin coated on the rubber layer, thereby minimizing thermal deterioration of the rubber layer in advance. A suitable firing temperature pattern that allows for low and good firing is stored as a current value pattern flowing through the near-infrared irradiation device, and firing is performed by controlling the output of the near-infrared irradiation device based on this current value pattern. As a result, a high-performance heat fixing roller with high image quality and excellent durability can be stably manufactured at low cost.

[Brief explanation of drawings]

Fig. 1 is a diagram schematically showing an example of a system of a firing device used in carrying out the present invention, and Fig. 2 is a schematic diagram showing an example of a heating furnace equipped with a near-infrared irradiation device used in carrying out the present invention. The cross-sectional view and FIG. 3 are graphs showing a temperature increase curve of the furnace temperature in one embodiment of the present invention. 1...Near infrared lamp 2...Fluororesin coating 3...Heat fixing roller 4...Metal Each axis 5......Rubber layer 6...Heating furnace 8...Output kaninit 13...Data logger Figure 2 Figure 3

Claims (1)

[Claims] (1) A rubber layer is provided on the metal core, this rubber layer is coated with fluororesin, and then, for firing, the metal core coated with fluororesin is placed in a heating furnace equipped with a near-infrared irradiation device. In the method for manufacturing a heat fixing roller in which near-infrared rays are irradiated from near the surface of the roller to heat and bake, an appropriate baking temperature pattern that minimizes thermal deterioration of the rubber layer and achieves good baking is determined in advance in the vicinity of the surface. The present invention is characterized in that a current value pattern flowing through the infrared ray irradiation device is stored in a storage device, and the output of the near-infrared irradiation device is controlled based on the stored current value pattern to heat and bake the fluororesin. A method of manufacturing a heat fixing roller.