JPH01281480A - Fixing rotor and fixing device - Google Patents

Abstract

PURPOSE:To reduce the offset of toner, to prevent the stain of a rotor and the smudge of an image on a transfer material and to improve the durability of the rotor by making a heat resistant rubber layer contain fluorine surfactant. CONSTITUTION:A heater 8 is provided in a fixing rotor 2, which has a metallic hollow rotor 6 such as a pipe made of aluminum or stainless steel and the heat resistant rubber layer 7 is thinly formed on the surface of the pipe. The heat resistant rubber layer 7 is appropriately formed of, for example, silicone rubber or fluorine rubber, etc. And the fluorine surfactant is mixed into the heat resistant rubber layer 7 of the fixing rotor 2. Thus, the stain on the surface of the rotor and the smudge of the image can be prevented and the durability of the rotor can be improved.

Description

Detailed Description of the Invention -f The present invention is suitable for heat-fixing a toner image formed on a recording material such as a transfer material in an image forming apparatus such as an electrophotographic method or an electrostatic recording method. The present invention relates to a fixing rotating body and a fixing device used.

Conventionally, in image forming apparatuses such as electrophotographic systems and electrostatic recording systems, heat fixing is used to fix a toner image as a permanent image on a recording material F such as a transfer material on which a toner image is formed. The device is in use. The fixing device, for example,
As shown in the figure, it is composed of a pair of rotating bodies: a heating fixing rotating body 2 and a pressing elastic rotating body 1. The fixing rotary body 2 has (1) polytetrafluoroethylene (PTFE) on the surface layer of a hollow core metal 6 made of aluminum, iron, etc.
(2) Release silicone rubber, fluororubber, etc.! coated with a highly heat-resistant "mu material*47", or
or (3) it is formed by further coating the surface of the heat-resistant rubber material 7 with a thin layer of Teflon resin. Further, the fixing rotary body 2 has a heater 8 inside the hollow core bar 6.
is placed and heated to a predetermined temperature.

On the other hand, the pressurizing elastic rotating body 1 has a core metal 3 made of iron, stainless steel, etc., covered with an elastic body 4 having release properties such as silicone rubber or fluororubber, and further covered with Teflon resin;
It is formed by forming a thin layer 5 of h.

The fixing rotating body 2 and the pressing elastic rotating body 1 are first pressed against each other by a suppressing means (not shown) such as a spring and rotated. Furthermore, is it established? c! ! In this example, a temperature measuring element 12 such as a thermistor is installed adjacent to or in contact with the surface of the fixing rotor 2, and monitors the surface temperature of the fixer rotor 2, and performs control at stage 1 (not shown). By controlling the voltage applied to the heater 8, the surface temperature of the fixing rotating body 2 is brought to the set value tni.

The transfer material 15 to which the toner image 16 has been transferred in the door 2 constant n device is guided between the fixing rotary body 2 and the fF addition rotary body 1 via the one-person log guide 14, and the constant R is It is done. Furthermore, the transfer material 15 is discharged via a paper discharge guide 17.

Further, the transfer material 15 wrapped around the fixing rotary body 2 is separated by the separation claw 1.
It is peeled off by 3. Further, the cleaning pad 9 removes toner, paper dust, etc. offset from the transfer material 15F to the surface of the fixing rotary body 2.

&"L 扛上 1L 工J 二台" = を 澾"1 layerHowever,
The fixing rotating body whose surface is coated with Teflon resin or the like and carved as in (1) has relatively good heat resistance and mold releasability.

Due to the high hardness of the surface of the rotating body, when transfer paper is used as a transfer material, it is not possible to press the fibers of the transfer paper and the H&male toner image, resulting in weak fixation (which tends to occur). 6 In addition, as shown in item (2), the fixing rotating body is formed by coating the surface with a heat-resistant rubber material with excellent mold release properties, and the surface of the rotating body is made of a soft rubber material. Because of this, the surface of the rotary body has a low hardness, and has the advantage of being highly effective in pressing the retoner image onto the transfer paper fibers and acid amount, achieving good fixing. If a large amount of silicone oil, etc. is applied to the surface of the rotating body in order to solve the toner offset problem, the surface rubber layer will swell, causing wrinkles on the transfer material. Ta.

Recently, attempts have been made to improve the charging characteristics by dispersing carbon powder in the surface rubber layer to solve the toner offset problem. However, in order to make this method effective, a large amount of carbon powder must be added to the surface rubber layer, resulting in a problem that the mold releasability of the rotating body decreases. The method is also not completely satisfactory.

In order to solve the problems of the fixing rotor in (1) and (2) above, as mentioned in (3) above, a thin layer of Teflon resin is further coated on the surface of the heat-resistant rubber material. A fixing rotating body constructed of the following has been proposed. The rotating body for fixing having such a structure does not cause problems such as swelling of the rubber layer forming the inner layer even when applied to the silicone rubber resin coating layer, and has the advantage of relatively good fixing performance. However, since the surface layer of the fixing rotating body is formed of a thin Teflon resin coating layer, the surface is easily scratched and lacks durability.Furthermore, the manufacturing process of such a rotating body is complicated and the manufacturing cost is high. The problem is that it becomes large.

Uninvented names, etc. are the results of many research experiments aimed at obtaining a fixing rotating body with improved release properties and charging characteristics, and a fixing device 4 using such a rotating body. By forming a thin heat-resistant rubber layer on the surface of the rotary body and mixing a two-part surfactant into the heat-resistant rubber layer, the eyebrow shape and 171t characteristics of the fixing rotary body are improved. , it reduces the toner offset phenomenon without applying a large amount of silicone oil, prevents stains on the surface of the rotating body, prevents stains on the image on the transfer material 14, and significantly improves the durability of the rotating body. I have found that Noh can be enhanced.

1 unreleased! ! 1 was made based on this new knowledge.

Therefore, unfinished I! The purpose of 1 is l! ll type property and charging characteristics are improved, resulting in reduced toner offset.
If = prevents stains on the rotating body and images on the transfer material,
! , L, It is an object of the present invention to provide a fixing rotating body and a fixing unit 1Jcft which can improve the durability of the rotating body.

↓W for-” The above object is achieved by a fixing rotating body according to an uninvented invention.

To be safe, the uninvention is a fixing device in which a heat source is provided inside a hollow metal rotating body (a heat-resistant rubber layer is formed on the convex surface of the hollow metal rotating body). In the rotating body, the heat-resistant rubber layer No. 111 is a constant-n rotating body characterized in that the heat-resistant rubber layer contains a large surfactant.

Also 11. According to another aspect of the invention, there is provided a rotating member for heating and fixing an image on a transfer material, and an elastic rotating member for pressing and conveying at least an elastic layer of the transfer material against the rotating member for fixing. In the fixing device having a body, a thin heat-resistant rubber layer is provided on the surface of the onion wear rotary body,
There is provided a fixing device characterized in that the heat-resistant rubber layer contains a fluorine surfactant.

Mitate 1 Next, the fixing rotor and fixing device according to the present invention will be explained in more detail with reference to the drawings.

FIG. 1 shows an embodiment of a fixing rotary body according to 1!1 and a fixing device δ using the rotary body. It is composed of a pair of rotating bodies: and a pressurizing elastic rotating body l.

The fixing rotary body 2 and the pressurizing elastic rotary body 1 are pressed against each other by a pressing means (not shown) such as a spring at a pressure of 4 to 10 kg, and rotate. A heater 8 is provided. The surface temperature of the fixing rotor 2 is detected by a temperature measuring terminal 12 such as a thermistor placed in contact with the rotor 2, and a control means (not shown) is applied to the surface of the fixing rotor 2.
By controlling the voltage of the heater 8 at 1, for example, 16
The temperature is controlled to a desired set temperature of 0 to 190°C.

The transfer material 15 to which the toner image 16 has been transferred is transferred to the entrance guide 1
4 to between the fixing rotating body 2 and the pressing elastic rotating body 1, fixing is performed, and the paper is discharged via the paper discharging guide 17. Also, the transfer material 1 wrapped around the fixing rotating body 2
5 is separated into 8# by the separation claw 13.

The surface of the fixing rotary body 2 is cleaned with a cleaning pad 9 to remove paper dust of a transfer material (for example, transfer paper) adhering to the surface and toner images on the transfer paper. The cleaning pad 9 also serves to apply a release agent such as silicone oil or surfactant to the surface of the fixing rotor 2 in order to prevent the toner image from being offset from the transfer paper.The cleaning pad 9 is made of Teflon resin. etc. Mi5
Formed heat-resistant Hue! RetoIO is fixed in a frame 11 made of heat-resistant resin or the like, and the heat-resistant felt 10 is impregnated with a mold release agent.

In this embodiment, the fixing rotary body 2 has, for example, an inner diameter 17+n.
m, has a metal hollow rotating body 6 like a vibrator made of aluminum or stainless steel with an outer diameter of 20 mm, and a heat-resistant rubber layer 7 with a thickness of 0.2 mm on the surface of the pipe.
It is applied in a thin layer of ~2.0 mm. The heat-resistant rubber layer is preferably formed of, for example, silicone rubber, raw rubber, or the like.

The pressing elastic rotating body l facing the fixing rotating body 2 is as follows:
The core metal 3 is made by plating the surface of iron or made of stainless steel.

The elastic layer 4 formed on the surface of the core metal 3 and the elastic layer P+
and a Teflon resin layer 5 coated on the surface of 3.

In this embodiment, the core metal 3 of the pressing elastic rotating body 1 has a diameter of 8 to 14 mm per strength, and may be made larger if necessary. is a sponge layer made by foaming silicone rubber, most of which are closed cells, and the thickness of this sponge layer 4 is 2 to 2.
3 mm, necessarily referred to as I-. 1-men copolymer (PFA
) etc. is used, and the surface 1- of the sponge Pft4 is coated with a thickness of 0.02 to 1 mm.

According to the second invention, a fluorocarbon surfactant is mixed into the heat-resistant rubber layer 7 in order to improve the releasability and charging characteristics of the fixing rotor 2.

7. Examples of surfactants include fluorinated alkyl esters, perfluoroalkyl polyoxyethylene ethanol, perfluorofurkyl carboxylates, perfluoroalkylammonium salts, perfluoroalkyl betaines, perfluoroalkyl amine oxides, and perfluoroalkyl betaines. There are fluoroalkyl ethylene oxide adducts, perfluoroalkyl phosphorus M Nisdel, non-dissociable perfluoroalkyl compounds, etc.For example, Yukodyne (trade name, Daikin Chogyo Co., Ltd. 5i and ETTOP (trade name, manufactured by Mitsubishi Metals)
etc. are preferably used.

Two 2. i. The surfactant is 0.003 to 1.0 tonne %, preferably 0.003 to 1.0 tonne %, based on the total weight of the heat-resistant rubber layer 7.
01 to 0.5 tonne% is mixed. The addition f of the fluorine-based surfactant to the heat-resistant rubber layer 7 is o.

If it is less than 0.03%, the effect of removing the surface charge of the fixing rotor will be reduced. In addition, the addition of the two-strand surfactant is 1. o When the amount exceeds % by weight, the fixing rotating body 2
During the production of silicone rubber, there is a tendency for curing failure to occur during vulcanization, resulting in poor Itf performance.

Next, the effects of the fixed 4'7 device constructed according to the present invention will be explained.

In this embodiment, the toner image 16 of the transfer material 151 is ,
A laser beam that uses an OPC (organic semiconductor) as a photoreceptor, and after negatively charging the photoreceptor, exposes it to image using an image exposure method to form a latent image, and then performs image formation by using a negative toner and performing a reversal phenomenon. It was formed using a printer.

Therefore, the image surface side of the transfer material 15 has negative polarity.
A toner image 16 is carried thereon, and the second side of the transfer material 15 is charged with a plus (positive polarity) charge applied during the transfer process. When such a transfer material 15 is passed between the fixing rotating body 2 and the pressing elastic rotating body 1 which are rotating in contact with each other, the rotating body 2 and the pressing elastic rotating body 1 have a constant r. , as shown in the fsZ diagram, the #f voltage is applied to the positive and negative sides, respectively.

In general, when looking at the friction band properties of silicone rubber and Teflon resin against paper, it is found that silicone rubber and Teflon resin tend to be negatively charged1. However, as a result of research experiments conducted by the present inventors,1 In the fixing 'A' 21, which has a structure in which the wearing rotary body 2 and the pressurizing elastic rotary body L are brought into contact with each other and rotated, in In a conventional fixing device that uses a rotating body for fixing, when transfer paper is used as a transfer material, it was found that the surface potential of the rotating body for fixing is charged to +2 to +3 KV. . The reason for this is that when the fixing rotary body 2 rotates in contact with the pressing elastic rotary body 1, a frictional force is generated between the two rotary bodies, and the transfer paper is conveyed while being held between the two rotary bodies. It is understood that this is due to this innocence.

In a normal fixing device, the surfaces of the fixing rotor 2 and the pressing elastic rotor L are charged as shown in FIG. Therefore, a portion 20 of the toner image 16 on the transfer material 15 that is passed between the two rotating bodies is offset to the surface of the fixing rotating body 2.

On the other hand, according to the present invention, since the fluorine-based surfactant is mixed into the surface rubber layer 7 of the fixing rotor 2, the electrical resistance of the rubber layer 7 decreases, and the surface potential of the fixer rotor 2 decreases. ＋
It became impossible to reduce the value to below IKV. An experiment was conducted by attaching the constant R device of this example to a laser beam printer. Laser beam printers use an OPCL-based semiconductor as a photoreceptor, and after negatively charging the photoreceptor, image exposure is performed to form a PpI image. l' l
- Image formation was performed by a reversal phenomenon using a toner, and a negative toner image was formed on a transfer material (transfer paper). Paper passing speed 1 in the fixing device is approximately 50mm/5e
There was a cffi.

According to this experiment, even after fixing 10,000 sheets, almost no dirt was observed on the surface of the constant n rotating body 2, and the amount of toner accumulated in the cleaning bay 9 was reduced to 1↑J by a large amount.

Incidentally, in order to effectively remove the charged charge on the surface of the fixing rotary body 2, the metal tape 6 of the fixing rotary body 2 is
It is grounded via a conductive bearing or by bringing a conductive spring into contact with the vibro. Also, cleaning pa・
, It is preferable that the fluorine-based surfactant is contained in not only silicone oil but also a thread surfactant in the 4th part of the fixing rotary body 2. Durability can be improved, and there is also an effect of preventing toner offset to the fixing rotating body.

According to the present invention, the pressing elastic rotary body 1 is not limited to the one-recording configuration, and the surface of the fixing rotary body 2 is charged to a polarity opposite to that of the toner image by passing the transfer material. If the structure is suitable, it can be made into a duty structure.

What is important in the present invention is that the rubber layer 7 of the fixing rotor is formed by adding a two/large surfactant to the rubber layer 7 of the fixing rotor.
The fluorine thread surfactant contained in the rubber layer 7 has heat resistance and is stable at a temperature of around 180 to 200"C when used as a rotating body for fixing, and may not be extracted from the rubber layer 7. At least the effects of No. 7 last for a long period of time, and the durability of the fixing rotor can be greatly increased.Other surfactants decompose at the temperatures listed in section 1 and cannot produce the desired effects.

In the explanation of the above embodiment, the fixing rotary body and the heating elastic rotary body are explained as roll-shaped rotary bodies, but they are not limited to this, and may also take the form of belt-shaped rotary bodies, for example. be.

Further, the cleaning felt is not necessarily necessary if the amount of toner offset is small.

Furthermore, as shown in FIG. 3, the present invention may have a configuration in which the pressurizing elastic rotating body l has only a rubber layer 4, and the silicone rubber of this elastic layer 4 contains a fluorine-based surfactant as described above. Even better effects can be achieved by adding agents.

As explained above, the fixing rotating body and fixing device of the present invention
The device has a structure in which a heat-resistant thin rubber layer on the surface of the rotating body contains a surfactant.
It can improve the mold release and charging characteristics, reduce the offset of the toner image to the rotating body for constant n, and prevent stains on the surface of the rotating body and the image. Significantly improved durability1. It has the effect of being able to encourage people.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing an embodiment of a fixing device using a fixing rotating body according to the present invention. FIG. 2 is a diagram showing the charging state 1g of each rotating body in the fixing device according to the present invention. FIG. 3 is a schematic cross-sectional view of a fixing device using a fixing rotating body according to the present invention. l: Pressurizing elastic rotor 2: Fixing rotor 7: Heat-resistant rubber layer 8: Halogen heater 9: Cleaning per 71 10: rI# thermal felt 12: Temperature measuring element 13: Separation claw 15: Transfer material

Claims (1)

[Scope of Claims] 1) A fixing rotor in which a heat source is provided inside a hollow metal rotor, and a thin heat-resistant rubber layer is formed on the surface of the hollow metal rotor. A fixing rotating body, wherein the heat-resistant rubber layer contains a fluorosurfactant. 2) A fixing device having a fixing rotating body that heats and fixes a toner image on a transfer material, and a pressing elastic rotating body that has at least an elastic layer and presses the transfer material against the fixing rotating body and conveys the fixing material. A fixing device characterized in that a thin heat-resistant rubber layer is provided on a surface of a rotating body, and the heat-resistant rubber layer contains a fluorosurfactant.