JPH10301431A - Fixing device and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device provided with a fixing device where the wear of a heating member and a pressing member is not caused, by which excellent image quality is obtained and whose reliability is excellent by preventing the occurrences of problems such as the defective image of releasing agent oil stripes or the like on a copy image, the deterioration of the releasing performance of the surface of a fixing member and paper jamming caused by winding due to the insufficiency of the supplied quantity of a releasing agent. SOLUTION: In the fixing device having the fixing member constituted of the heating member 1 and the pressing member 2 and a releasing agent supplying device; the releasing agent supplying device 3 supplies a releasing agent supply sheet 31 abutting on at least either of the heating member 1 and the pressing member 2, and the releasing agent supply sheet is constituted of a heat-resistant base sheet and a releasing agent holding layer incorporating the releasing agent formed of an elastic body layer having the basis weight of 1-500 g/m<2> , and the releasing agent holding quantity of the releasing agent supply sheet is made within the range of 1/10 to twice of the basis weight of the elastic body layer. An image is formed by an electrophotographic method by using the fixing device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention includes an image forming method including a step of fixing a transfer member having an unfixed color toner image using a fixing member including a heating member and a pressing member, and a fixing device for the method. The present invention relates to an image forming apparatus using an electrophotographic process, such as an electrophotographic copying machine, a facsimile, and a printer.

[0002]

2. Description of the Related Art Conventionally, in a copying machine or the like utilizing an electrophotographic process, it is necessary to fix an unfixed toner image formed on a transfer body to a permanent image. A pressure fixing method, a heat fixing method, and the like are known. However, the above-described solvent fixing method and pressure fixing method have drawbacks in environmental problems, fixing performance, and the like, and at present, both are not widely used. Therefore, for fixing an unfixed toner image, a heat fixing method in which toner is melted by heating and adhered onto a transfer member is most widely adopted.

In this heat fixing method, a fixed pressure is applied between a pair of rolls, at least one of which is heated, that is, a heating roll and a pressure roll, and fixing is performed by passing a transfer member having an unfixed toner image. A heating roll method is known, and this method has advantages such as lower power consumption and less danger of ignition due to paper jam in the fixing unit as compared with the case of using other heat fixing devices. This is the most widely used fixing method.

As the heating roll in the heating roll system, a cylindrical cored bar having a surface coated with a heat-resistant elastic material such as silicone rubber or fluoro rubber, polytetrafluoroethylene (PTFE) or tetrafluoroethylene Fluoroalkyl vinyl ether copolymer (P
Those coated with a heat-resistant resin such as FA) are used.
On the other hand, as the pressure roll, when the pressure contact with the heating roll, the surface of the cylindrical core metal is coated with a heat-resistant elastic material such as silicone rubber, fluorine rubber, etc. so as to have a certain contact width, and Polytetrafluoroethylene (PTFE) or tetrafluoroethylene-
Perfluoroalkyl vinyl ether copolymer (PFA)
Those coated with a heat-resistant resin such as are used.

However, when this heating roll system is used, a part of the unfixed toner on the transfer body is unsatisfactory because of the poor releasability of the unfixed toner on the transfer body and the heat-resistant elastic body on the heating roll surface. The toner is transferred to a heating roll, and the toner is re-transferred to the rear end of the transfer member or the next transfer member passing through the transfer member, thereby contaminating the transfer member. The transfer member wraps around the heating roll and acts as an adhesive, causing a paper jam.

Therefore, in order to prevent these problems from occurring, it is common practice to apply silicone oil or the like as a release agent to the surface of the heating roll. As the release agent supply device for applying the release agent, FIGS.
The one shown in (d) is known.

[0007] 1) The release agent is passed through a felt 61 from a release agent storage container using a rubber hardness type A durometer.
The coating agent is applied to a pickup roll 62 made of silicone rubber of 0 to 50, and the release agent is applied to the heating roll 60 by a donor roll 63 made of silicone rubber of 20 to 50 with the same rubber hardness type A durometer in contact with the pickup roll. Donor roll method (Fig. 4
(A)).

[0008] This method uses 300 centistokes (c
It is currently widely used in color copiers because it is suitable for supplying low viscosity silicone oils of the order of s). It is for the following reasons. That is, in the case of a color image, it is necessary to form a toner-fixed image having a high gloss, so that a toner having a low melt viscosity at the time of fixing is used. If the viscosity is not used, the toner is offset to the heating roll.

However, in this method, toner or paper dust is deposited on the donor roll that comes into contact with the heating roll over time, and streak-like unevenness is likely to occur in the supply of the release agent. There are problems such as the occurrence of image defects such as unevenness, and the fact that the deposits of toner and paper powder are always in contact with the heating roll, thereby reducing the releasability of the heating roll and shortening the life of the roll. . Furthermore, in this method, in order to uniformly supply the release agent to the heating roll,
The supply amount of the release agent increases. As a problem due to the large supply amount of the release agent, first, a tank for the release agent is required. Further, at the time of double-sided copying or the like, there is a problem that the release agent on the copy is transferred to the transfer roll, the photoconductor or the transfer member in the copying machine, which causes a paper conveyance failure and an image defect. When the problem of causing a large supply of the release agent is addressed by reducing the supply amount,
This time, the problem of uneven release of the release agent occurs. In order to solve these problems, the invention disclosed in Japanese Patent Application Laid-Open No. 6-195011 uses a cleaning member having particles absorbing a release agent, but it is not yet sufficient.

2) A web system in which a non-woven fabric 64 impregnated with a release agent is pressed against a heating roll 60 to apply the release agent to the surface (FIG. 4B). This method is suitable for supplying a very small amount of silicone oil having a high viscosity of about 10,000 cs, and is currently widely used in black-and-white copying machines. The black and white toner has excellent releasability of the toner itself due to the high molecular weight of the binder resin and the inclusion of wax. Therefore, unlike the color toner, there is no problem in the releasability even by using a high-viscosity silicone oil. However, when this method is applied to black-and-white toner, there is a problem in terms of wear of the heating roll due to a small supply amount of the release agent, and when it is applied to color toner, it is necessary to release the color toner. It is difficult to impregnate a nonwoven fabric with a low-viscosity silicone oil and retain it for a long period of time, and oil spillage, a phenomenon that exudes, occurs. In order to prevent this, it is necessary to use a silicone oil having a high viscosity of about 10,000 cs, in which case the releasability cannot be satisfied. Furthermore, in this method, there is a disadvantage that the supply of the release agent tends to be uneven due to the fibrous irregularities of the nonwoven fabric.

Japanese Unexamined Patent Publication (Kokai) No. 6-3999 proposes to provide an oil retaining layer on a nonwoven fabric in order to improve the oil retaining property of the release agent in this system. However, in this case, the oil absorption of the nonwoven fabric is limited, and
There is a drawback that the supply of the release agent tends to be streak-like unevenness.

3) A Wick & Blade system in which a release agent is applied from the release agent storage container 65 to the surface of the heating roll 60 using a nonwoven fabric 66 such as felt (FIG. 4C). 4) An oil exuding roll system in which a release agent supply roll 67 in which a release agent is sealed is pressed against the outer peripheral surface of the heating roll 60 to apply the release agent to the surface (FIG. 4D). These methods have the disadvantage that a small amount of offset toner or paper dust accumulates on the heating roll as the number of copies increases, resulting in insufficient release agent supply and uneven supply amounts.
Dirt deposited on the surface of the contact-type release agent supply member is constantly pressed by the heating roll, so it also contaminates the surface of the heating roll, degrades the release property of the heating roll surface, and extends the service life of the heating roll. There is a problem of shrinking.

As described above, in the conventional contact-type release agent supply device, unevenness in the supply amount of the release agent, insufficient supply, and the case where a low-viscosity release agent suitable for releasing the color toner is supplied. Oil spills, tank space problems due to increased supply, problems such as part contamination in copiers due to excess supply, resulting in mold release defects, image defects due to release agent oil streaks on copy images, glossiness There were problems such as unevenness, shortening of the service life of the heating roll, enlargement of the copying machine, and shortening of the service life of parts in the copying machine.

[0014]

SUMMARY OF THE INVENTION The present invention has been made to improve or eliminate the above-mentioned disadvantages of the prior art. That is, the present invention has been made with respect to a fixing device having a fixing member provided with a release agent supply device, and its object is to provide an image defect such as a release agent oil streak on a copy image and a surface of the fixing member. To provide a high-quality, high-reliability fixing device that prevents a problem such as a paper jam due to wrapping due to a decrease in release property or an insufficient supply of a release agent and that does not cause abrasion of a heating member and a pressing member. It is in. Another object of the present invention is to provide an image forming method capable of forming a high-quality color copy image without a release agent oil streak and unevenness in gloss over a long period of time.

[0015]

Means for Solving the Problems In a fixing device having a fixing member comprising a heating member and a pressing member, the present inventors provide a releasing agent on at least one surface of the heating member and the pressing member. It has been found that the above object can be achieved by providing a release agent supply device capable of uniformly and stably supplying, and the present invention has been completed.

The fixing device of the present invention has a fixing member comprising a heating member and a pressure member, and a release agent supply device, and the release agent supply device contacts at least one of the heating member and the pressure member. For supplying a release agent supply sheet, the release agent supply sheet is a heat-resistant base sheet, 1 to
A release agent holding layer containing a release agent formed from an elastic layer having a basis weight of 500 g / m ² , wherein the release agent holding amount of the release agent supply sheet is the basis weight of the elastic layer. It is characterized in that it is in the range of one tenth to two times.

According to the image forming method of the present invention, a step of forming a latent image on a latent image holding member, a step of developing the latent image using a developer, and a step of transferring the formed toner image onto a transfer member ,
It has a step of fixing the toner image on the transfer body using a fixing member consisting of a heating member and a pressure member,
In the fixing step, the release agent supply sheet is fixed by bringing the release agent supply sheet into contact with at least one of a heating member and a pressure member, and the release agent supply sheet is provided with a heat-resistant base sheet and 1 to 500 g / g. a release agent holding layer containing a release agent formed from an elastic layer having a basis weight of m ² , wherein the release agent holding amount of the release agent supply sheet is 10 minutes of the basis weight of the elastic layer. The fixing is performed in a range of 1 to 2 times of the above.

[0018]

FIG. 1 shows an embodiment of a fixing device according to the present invention, and is a schematic configuration diagram. The fixing member includes a heating roll 1 and a pressure roll 2, and a transfer body 4 carrying unfixed toner passes between the two rolls. The heating roll 1 has a structure in which an elastic layer 13 and a surface layer 14 are provided on a metal core 12 having a heating lamp 11 therein, and the pressure roll 2 has a heating lamp 21 therein. It has a structure in which an elastic layer 23 and a surface layer 24 are provided on the provided metal core 22. On the side of the heating roll, a release agent supply device 3
Is provided. The release agent supply device 3 includes a release agent supply sheet 31, a shaft 32 for winding the release agent supply sheet,
A pressing roll 33 for bringing the release agent supply sheet drawn from the winding shaft into contact with the heating roll, a winding shaft 34 for winding the release agent supply sheet after contacting the heating roll, and 1 to 10 mm / And a control means 35 for winding the release agent supply sheet at a speed per minute. The materials constituting the surface layers of the heating roll 1 and the pressure roll 2 in the present invention include silicone rubber, fluorine rubber, polytetrafluoroethylene (PTF).
E) and a fluororesin such as a tetrafluoroethylene-perfluoroalkylvinylether copolymer (PFA) can be used, but from the viewpoint of abrasion resistance, a fluororubber and a fluororesin can be preferably used.

The release agent supply sheet used in the present invention comprises a heat resistant base sheet and a release agent holding layer for holding the release agent. The heat-resistant base sheet is not particularly limited as long as it has a heat-resistant sheet shape having a melting point of 200 ° C. or more, and any sheet can be used. For example, a nonwoven fabric (web) made of aromatic polyamide fiber, polyamide fiber, polyphenylene sulfide fiber, polyester fiber, or the like can be used. Further, a film-like material such as a polyimide film can also be used. The thickness of these sheets is preferably 0.1 mm or less from the viewpoint of the flexibility of the sheets, and is preferably 0.01 mm or more from the viewpoint of strength.

As the release agent holding layer, for example, a layer having a rubber elastic body, specifically, silicone rubber can be preferably used. It is preferable to use a silicone RTV rubber as the silicone rubber. Silicone RTV rubber is Si
A siloxane having a reactive group such as —OH, Si—OR, Si—H, or Si—CHＣＨCH ₂ is crosslinked with a catalyst to form a rubber elastic body, and is a curing mechanism of either an addition type or a condensation type. Can also be used.

In the present invention, the silicone rubber used for the release agent holding layer preferably has a rubber hardness of 30 or less, particularly 5 to 30 in Asker C hardness. Silicone rubber having an Asker C hardness of 30 or less is excellent in that it swells with a release agent such as silicone oil, absorbs and retains it, and has a sufficient amount of a low-viscosity release agent for the applied amount. Can be held without spillage. In the case of a rubber having a hardness of more than 30 as measured by an Asker C hardness meter, the filler content is large or the crosslink density of the silicone rubber is high. Here, Asker C hardness is
It means the hardness required by the Japan Rubber Association Standard SRIS 0101.

Silicone rubber having an Asker C hardness of 5 to 30 is softer than silicone rubber having a hardness of 30 to 60 with a type A durometer which is usually used for rolls. The released release agent supply sheet can uniformly contact the heating roll even when the outermost surface layer is worn, so that the supply unevenness of the release agent does not occur, and the release agent on the copy is used. The generation of streaks (oil streaks) can be prevented. When silicone rubber having an Asker C hardness of 5 to 30 is used, the releasability of the surface of the heating roll or the pressure roll hardly decreases, and the life of these rolls can be extended.
One reason for this is that the supply of the release agent is uniform. Further, when the release agent is impregnated in silicone rubber having an Asker C hardness of 5 to 30, a liquid release agent is used. Since the silicone rubber swells while containing a large amount, dirt such as paper dust and toner from the heating roll and the pressure roll may be taken into the silicone rubber layer. One of the reasons is considered to be that the amount of soil that keeps contacting is substantially reduced.

If a rubber having an Asker C hardness of more than 30 is used, unevenness in the supply of the release agent occurs due to the shape of the abrasion when the abrasion occurs, and image defects such as oil streaks occur on the copy. In addition, dirt from the heating roll accumulates in the outermost surface layer of the release agent supply sheet and continues to contact the roll, and the life of the roll is shortened due to a decrease in the releasability of the roll surface.

In the present invention, the basis weight of the release agent holding layer is
1 to 500 g / m ² , and 5 to 20 g / m ^2.
It is preferably 0 g / m ² , more preferably 1 g / m ^2.
0 to 100 g / m ² . When the grammage is less than 1 g / m ² , the release agent holding layer cannot absorb the unevenness of the roll surface or the heat-resistant base sheet and cannot be deformed, and uneven supply of the release agent occurs. If the grammage is greater than 500 g / m ² , the release agent supply sheet will be too large when stored in a roll form, causing inconvenience in work.

The release agent holding amount Y of the release agent supply sheet
Is Y = X / 1 with respect to the basis weight Xg / m ² of the release agent holding layer.
It is preferably in the range of 0 to ² Xg / m ² , that is, in the range of 1/10 to 2 times the basis weight of the elastic layer. If the release agent holding amount is more than twice the basis weight of the elastic layer, the release agent exudes from the release agent holding layer, and oil spills. On the other hand, if the weight is less than 1/10 of the basis weight of the elastic layer, the amount of the release agent applied to the heating roll is insufficient, and it is difficult to maintain the anti-offset property and the release property of the fixing member surface.

The release agent used in the present invention includes:
Silicone oil can be used. Silicone oils include dimethyl silicone oil, phenylmethyl silicone oil, alkyl-modified silicone oil, fluorosilicone oil, carboxyl-modified silicone oil, polyether-modified silicone oil, amino-modified silicone oil, mercapto-modified silicone oil, and methyl group of dimethyl silicone oil. Part of the
A modified silicone oil substituted with a polyoxyalkylene group, amino group or long-chain alkyl group can be used, and a mixture thereof may be used.

The above silicone oil is 100
The viscosity is preferably from 5000 to 5000 cs, more preferably from 200 to 1000 cs. As described in connection with the prior art, from the viewpoint of the releasability of the toner, it is desirable that the viscosity of the silicone oil is low,
In the case of a higher viscosity silicone oil, it exhibits tackiness by itself and causes toner offset.
In the case of silicone oil having a viscosity lower than 100 cs, the surface temperature is 100 to 20 due to its volatility.
It is difficult to use the fixing member at 0 ° C. in contact with the fixing member.

The fixing member of the fixing device of the present invention includes a heating roll and a pressure roll as shown in FIG. 1, a heating roll and a belt using a pressure roll, and a pressure roll and a heating roll. Conventionally known fixing members of a fixing device, such as a device using a belt and a device using a belt on both the heating side and the pressure side, can be used.

FIG. 2 is a schematic sectional view of another embodiment of the fixing device of the present invention. The fixing device shown in FIG. 2 uses a belt on both the heating side and the pressing side. A heating device 19 is provided on the heating side, and the belt 15 includes an elastic roll 16 and a guide roll 17. And 18 and move in the direction of the arrow. Further, the belt 25 on the pressing side includes guide rolls 26, 27 and 28.
And move in the direction of the arrow. Release agent supply devices 3a and 3b are provided so as to be in contact with the heating side belt and the pressure side belt, respectively. These release agent supply devices have the same structure as that shown in FIG. 1, and include a release agent supply sheet 31a.
And 31b, shaft 3 for winding release agent supply sheet
2a and 32b, pressing rolls 33a and 33b for bringing the release agent supply sheet drawn from the winding shaft into contact with the belt, and winding shafts 34a and 34 for winding the release agent supply sheet after contacting the belt.
b, and control means 35a and 35b for winding the release agent supply sheet at a speed of 1 to 10 mm / minute. The transfer body 4 carrying the unfixed toner is
The belt is inserted between the belt 15 and the belt 25, and is heated and pressed between the two belts to perform fixing. Reference numeral 5 denotes a cleaning roll.

FIG. 3 is a schematic structural view of an image forming apparatus using the fixing device of the present invention. In this image forming apparatus, a charger 107 is provided around the photosensitive drum 108,
A developing device provided with developing devices 109 to 112 and a transfer drum 113 provided with a transfer corotron 115 are provided. The upper portion is composed of a lighting device 101, a color CCD 103, an image processing device 104, and a laser diode 105. A laser optical system 106 is provided, and further, a fixing device 116 having a structure shown in FIG. 1 is provided.

In order to form an image using this image forming apparatus, the surface of the photosensitive drum 108 is charged by the charger 107 and then the original 10 is scanned by the laser optical system.
The electrostatic latent image is formed by irradiating the second color separation image, and then a predetermined color toner image is formed by the developing device. This operation is repeated for each color to form a color toner image composed of four toners (cyan, magenta, yellow, and black) on the photosensitive drum. Next, after the toner image is collectively transferred onto the transfer paper 114 on the transfer drum 113, the fixing device 116
Is heated and fixed.

Next, the image forming method of the present invention will be described. In the present invention, as the latent image holding member, a member on which an electrostatic latent image is formed, such as an electrophotographic photosensitive member and a dielectric recording member, is used, and the electrostatic latent image is formed by a known method. Next, the electrostatic latent image formed on the latent image holding member is visualized by a known developing method using a developer. The formed toner image is transferred onto a transfer body such as paper by, for example, a transfer charger or the like, and then fixed in a fixing step. In the present invention, the fixing is performed by the fixing device described above. That is, a release agent supply sheet composed of a heat-resistant base sheet made of a heat-resistant sheet and a release agent holding layer made of an elastic layer having a basis weight of 1 to 500 g / m ² is heated by a heating member and a pressing member. And fixing is performed with the release agent holding amount of the release agent supply sheet in the range of 1/10 to 2 times the basis weight of the elastic layer.

In this case, the control of the release agent application amount is mainly performed by setting the release agent holding amount Y and controlling the winding speed of the release agent supply sheet in contact with the fixing member. The winding speed is not particularly limited, but is usually 1 to 3
mm / min. In this case, the take-up speed may be variably controlled by interlocking a take-up shaft with a drive source such as a step motor that facilitates speed control. For example, from the means for detecting the diameter of the sheet wound on the winding shaft or from the history data of the winding amount, the winding speed is not fixed, but the rotation speed of the winding shaft is fixed. It may be controlled. In addition, a change in the releasability of the surface of the fixing member, which is slightly deteriorated with time, is grasped in advance by an experiment or the like, and in order to supplement the releasability, the winding speed is increased to increase the amount of the release agent applied. Good. Furthermore, the number of copies, copy speed, image density, paper / OHP
The winding speed may be changed in accordance with the fixing conditions that change depending on the type of the transfer body such as a film, and the amount of the release agent applied may be minutely controlled.

The minimum amount of the release agent applied to maintain the releasing property of the color toner from the fixing member and the releasing property of the fixing member is about 0.1 to 1 mg / A4. For example, the amount of the release agent applied is set to 0.1 by the release agent supply device.
It can be adjusted to a range of from 1 mg / A4 to a uniform application. The release agent application amount is 1/10 to 1/1 of the release agent application amount conventionally required for uniform application.
100.

[0035]

Embodiments of the present invention will be described below.

Example A-1 (Preparation method of release agent supply sheet) A heat-resistant aramid fiber non-woven fabric (Nomex, 70 μm thick, manufactured by DuPont) was used as a heat-resistant base sheet, and a liquid silicone rubber (KE1225) was used for the non-woven fabric. (8% catalyst), Asker C
A hardness of 30, manufactured by Shin-Etsu Chemical Co., Ltd.) was degassed and impregnated in vacuum so that the basis weight of the heat-resistant base sheet became 10 g / m ² (X = 10), and then the liquid silicone rubber was cured. The formed sheet was impregnated with 300 g of dimethyl silicone oil at 5 g / m ² to obtain a release agent supply sheet. (Basis weight X = 10 g / m ² , release agent holding amount Y = X
/ 2) The release agent supply sheet was wound around an aluminum pipe as a winding shaft, and attached to a fixing device A having a configuration as shown in FIG.

Example A-2 (Preparation method of release agent supply sheet) A heat-resistant aramid fiber non-woven fabric (Nomex, 70 μm thick, manufactured by DuPont) was used as a heat-resistant base sheet, and a liquid silicone rubber (KE1225) was used for the non-woven fabric. (8% catalyst), Asker C
(A hardness of 30, manufactured by Shin-Etsu Chemical Co., Ltd.) was deaerated and impregnated in vacuum so that the basis weight of the heat-resistant base sheet was 500 g / m ² (X = 500), and then the liquid silicone rubber was cured. The formed sheet was impregnated with 300 cs of dimethyl silicone oil at 50 g / m ² to obtain a release agent supply sheet. (Basal weight X = 500 g / m ² , Release agent holding amount Y = X / 10) This release agent supply sheet is wound around an aluminum pipe as a winding shaft, and a fixing device having a configuration as shown in FIG. A.

Example A-3 (Production method of release agent supply sheet) A heat-resistant polyimide film (10 μm thick) was used as a heat-resistant base sheet, and a liquid silicone rubber (KE1225) was used as the film.
(Catalyst amount 6%), Asker C hardness 10, manufactured by Shin-Etsu Chemical Co., Ltd.)
Was coated to a thickness of 5 g / m ² on the heat-resistant base sheet surface, degassed in vacuum, and the liquid silicone rubber was cured. 5000c on the formed sheet
Then, 10 g / m ² of dimethyl silicone oil was impregnated to obtain a release agent supply sheet. (Basic weight X = 5 g / m ² , Release agent holding amount Y = 2X) This release agent supply sheet is wound around an aluminum pipe which is a winding shaft, and is fixed to a fixing device A having a configuration as shown in FIG. I attached it.

Example A-4 (Method of preparing release agent supply sheet) A heat-resistant polyimide film (10 μm thick) was used as a heat-resistant base sheet, and a liquid silicone rubber (KE1225) was used as the film.
(Catalyst amount 5%), Asker C hardness 5, manufactured by Shin-Etsu Chemical Co., Ltd.) with a thickness of 10 g / m ^{2 on} the heat-resistant base sheet surface, degassed in vacuum, and liquid silicone The rubber was cured. The formed sheet was impregnated with dimethyl silicone oil of 1000 cs at 10 g / m ² to obtain a release agent supply sheet. (Basic weight X = 10 g / m ² , Y =
X) The release agent supply sheet was wound around an aluminum pipe as a winding shaft, and attached to a fixing device A having a configuration as shown in FIG.

Example B-1 (Preparation Method of Release Agent Supply Sheet) A heat-resistant aramid fiber non-woven fabric (Nomex, 70 μm thick, manufactured by DuPont) was used as a heat-resistant base sheet, and a liquid silicone rubber (KE1225) was used as the non-woven fabric. (8% catalyst), Asker C
(A hardness of 30, manufactured by Shin-Etsu Chemical Co., Ltd.) was degassed and impregnated in vacuum so that the basis weight of the heat-resistant base sheet became 10 g / m ² , and then the liquid silicone rubber was cured. The formed sheet was impregnated with 5000 cs of an amino-modified silicone oil at 5 g / m ² to obtain a release agent supply sheet. (Basic weight X = 10 g / m ² , Y = X / 2) The release agent supply sheet was wound around an aluminum pipe as a winding shaft, and attached to a fixing device B having a configuration as shown in FIG.

Comparative Example A-1 (Preparation Method of Release Agent Supply Sheet) A heat-resistant aramid fiber nonwoven fabric (Nomex, 70 μm thick, manufactured by DuPont) was used as a heat-resistant base sheet, and liquid silicone rubber (KE1225) was used as the nonwoven fabric. (8% catalyst), Asker C
(A hardness of 30, manufactured by Shin-Etsu Chemical Co., Ltd.) was degassed and impregnated in vacuum so that the basis weight of the heat-resistant base sheet became 10 g / m ² , and then the liquid silicone rubber was cured. The formed sheet was impregnated with 300 cs of dimethyl silicone oil at 30 g / m ² to obtain a release agent supply sheet.
(Basic weight X = 10 g / m ² , Y = 3X) The release agent supply sheet was wound around an aluminum pipe as a winding shaft, and was mounted on a fixing device A having a configuration as shown in FIG.

Comparative Example A-2 (Preparation method of release agent supply sheet) A heat-resistant aramid fiber nonwoven fabric (Nomex, thickness 70 μm, manufactured by DuPont) was used as a heat-resistant base sheet, and a liquid silicone rubber (Shin-Etsu) was used as the nonwoven fabric. Chemical company KE1225 (catalyst amount 8
%) And Asker C hardness 30) were degassed and impregnated in a vacuum so that the basis weight of the heat-resistant base sheet was 500 g / m ² (X = 500), and then the liquid silicone rubber was cured. The formed sheet was impregnated with 300 cs of dimethyl silicone oil at 25 g / m ² to obtain a release agent supply sheet. (Basic weight X = 500 g / m ² , Y = X /
20) The release agent supply sheet was wound around an aluminum pipe as a winding shaft, and mounted on a fixing device A having a configuration as shown in FIG.

Comparative Example A-3 (Method of preparing release agent supply sheet) A heat-resistant polyimide film (thickness: 10 μm) was used as a heat-resistant base sheet, and a liquid silicone rubber (KE1225) was used as the film.
(Catalyst amount 6%), Asker C hardness 10, manufactured by Shin-Etsu Chemical Co., Ltd.)
Was coated to a thickness of ² g / m ² on the heat-resistant base sheet surface, degassed in vacuum, and the liquid silicone rubber was cured. 5000c on the formed sheet
Then, 2 g / m ² of dimethyl silicone oil was impregnated to obtain a release agent supply sheet. (Basic weight X = 2 g / m ² , Y =
X) The release agent supply sheet was wound around an aluminum pipe as a winding shaft, and attached to a fixing device A having a configuration as shown in FIG.

Comparative Example A-4 (Production method of release agent supply sheet) A heat-resistant polyimide film (thickness: 10 μm) was used as a heat-resistant base sheet, and a liquid silicone rubber (KE1225) was used as the film.
(Catalyst amount 8%), Asker C hardness 30, manufactured by Shin-Etsu Chemical Co., Ltd.)
Was coated to a thickness of 10 g / m ^{2 on} the surface of the heat-resistant base sheet, degassed in vacuum, and the liquid silicone rubber was cured. This sheet has 10,000 cs
Was impregnated with 10 g / m ² of dimethyl silicone oil to obtain a release agent supply sheet. (Basic weight X = 10 g / m ² , Y
= X) The release agent supply sheet was wound around an aluminum pipe as a winding shaft, and attached to the fixing device A with a configuration as shown in FIG.

Comparative Example B-1 (Method of preparing release agent supply sheet) A heat-resistant aramid fiber nonwoven fabric (Nomex, 70 μm thick, manufactured by DuPont) was used as a heat-resistant base sheet, and liquid silicone rubber (KE103) was used as the nonwoven fabric. , Asker C hardness 40, manufactured by Shin-Etsu Chemical Co., Ltd.) with respect to the heat-resistant base sheet surface at 10 g / m ^2.
, And then the liquid silicone rubber was cured. 1 on the formed sheet
000 cs amino-modified silicone oil at 10 g / m
^{2 was} impregnated to obtain a release agent supply sheet. (X = 10 g /
m ² , Y = X) The release agent supply sheet was wound around an aluminum pipe as a winding shaft, and attached to a fixing device B having a configuration as shown in FIG.

(Results of Effect Confirmation Test) Using a copying machine in which only the fixing unit of a color copying machine (Acolor, manufactured by Fuji Xerox Co., Ltd.) was modified, the image quality and the maintainability of the fixing member were evaluated. The test conditions were as follows: the image was full color, the area ratio of the image area to the non-image area was 70:30, and the paper was J paper (A4 transverse feed) manufactured by Fuji Xerox Co., Ltd.

As the fixing device A, as shown in FIG.
A heat roll fixing member composed of a heating roll and a pressure roll is used. The heating roll and the pressure roll cover the surface of an aluminum cylindrical core with a silicone rubber heat-resistant elastic body (the heating roll has a thickness of 3 mm, and has a thickness of 3 mm. The pressure roll used had a thickness of 2 mm) and the outermost surface was covered with a Teflon tube (thickness: 50 μm). Further, as shown in FIG. 1, the release agent supply device is attached so as to be in contact with the surface of the heating roll of the fixing device A, and the feeding speed of the release agent supply sheet is set between the start of copying and the completion of discharge of the transfer body. The test was performed at 10 mm / sec.

Further, as shown in FIG. 2, a fixing member comprising a heating belt composed of a heating belt and a pressure belt is used as the fixing device B, and the heating belt and the pressure belt are formed on a polyimide film (thickness: 30 μm). Was coated with a silicone rubber heat-resistant elastic body having a thickness of 0.4 mm, and the outermost surface thereof was coated with a fluororubber to a thickness of 15 μm. As shown in FIG. 2, the release agent supply device is attached so as to be in contact with the surfaces of the heating belt and the pressure belt of the fixing device B, and the feeding speed of the release agent supply sheet is from the start of copying to the completion of the transfer body discharge. During the test, the test was performed at 10 mm / sec.

Table 1 shows the results.

[0050]

[Table 1]

[0051]

According to the image forming apparatus of the present invention, the release agent having the above structure can supply the release agent uniformly and stably to at least one surface of the heating member and the pressure member in the fixing device. Since the supply device is provided, 1/10 to 1/1 of the release agent application amount conventionally required for uniform application
It is possible to apply evenly with an application amount of 00, so that image defects such as oil streaks on the copy image, releasability of the heating member and the pressing member surface decrease, winding due to insufficient release agent supply and This has the effect of preventing the occurrence of paper jams and the like and preventing the heating member and the pressing member from being worn. According to the image forming method of the present invention,
It is possible to form a high-quality and highly reliable color copy image for a long period of time.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of a fixing device of the present invention.

FIG. 2 is a schematic configuration diagram showing another embodiment of the fixing device of the present invention.

FIG. 3 is a schematic configuration diagram of an image forming apparatus using the fixing device of the present invention.

FIG. 4 is a schematic configuration diagram showing a releasability supply device of a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Heating roll, 2 ... Pressure roll, 3, 3a, 3b ... Release agent supply device, 4 ... Transfer body, 11 ... Heating lamp, 12 ...
Metal core, 13: elastic layer, 14: surface layer, 15: belt, 16: elastic roll, 17, 18: guide roll,
19: heating device, 21: heating lamp, 22: metal core,
23 ... elastic layer, 24 ... surface layer, 25 ... belt, 26,
27, 28: guide roll, 31, 31a, 31b: release agent supply sheet, 32, 32a, 32b: winding shaft, 33, 33a, 33b: pressing roll, 34, 34
a, 34b: winding shaft, 35, 35a, 35b
... Control means, 5 ... Cleaning roll, 60 ... Heating roll, 61 ... Felt, 62 ... Pickup roll, 63
... donor roll, 64 ... nonwoven fabric, 65: container for release agent storage, 66 ... nonwoven fabric, 67: release agent supply roll.

Claims (2)

[Claims] 1. A fixing device having a fixing member including a heating member and a pressing member and a release agent supply device, wherein the release agent supply device contacts at least one of the heating member and the pressure member. Supplying a supply sheet, wherein the release agent supply sheet comprises: a heat-resistant base sheet;
A release agent holding layer containing a release agent formed from an elastic layer having a basis weight of about 500 g / m ² , wherein the release agent holding amount of the release agent supply sheet is A fixing device, wherein the amount is in the range of 1/10 to 2 times the amount. 2. A step of forming a latent image on a latent image holding member, a step of developing the latent image using a developer, a step of transferring the formed toner image onto a transfer member, a heating member and pressure An image forming method including a step of fixing a toner image on a transfer body using a fixing member made of a member, wherein the fixing step includes bringing a release agent supply sheet into contact with at least one of a heating member and a pressing member. Wherein the release agent supply sheet comprises a heat-resistant base sheet and 1 to 500
and a release agent holding layer containing a release agent formed from an elastic layer having a basis weight of g / m ² , wherein the release agent holding amount of the release agent supply sheet is defined as the basis weight of the elastic layer. An image forming method, wherein fixing is performed in a range of 1/10 to 2 times.