JPS59126576A - Fixing device and roller for fixation - Google Patents

Abstract

PURPOSE:To obtain a fixing device of simple constitution which has ability in prevention against an offset by providing at least either of the 1st and the 2nd rotating body with a triboelectricity generating material which produces an electric field for sticking an adherend to a recording material. CONSTITUTION:When a copy switch is turned on, a fixing roller 1 starts rotating. The insulating elastic material layer 22 of a pressure roller 2 absorbs heat from the fixing roller 1 according to its rotation to expand, and then contacts heat-resistant nonwoven fabric 7 impregnated with an electrifying agent [e.g. formula I and formula II (R; C11-17 lauric acid, etc.) ] to supply the electrifying agent to the surface. The pressure roller 2 radiates its heat naturally after copying operation is completed and contracts again to leave the heat-resistant nonwoven fabric 7. Consequently, the thermal deterioration of the electrifying agent is reduced greatly and an offset is reduced excellently.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic device, an electrostatic recording device, or a unit such as a fixing roller or a coating member for contacting or contacting a recording material.

Generally, when contact-fixing a recording material (such as paper) that electrically supports a toner image with positive or negative polarity, there is an offset in which toner particles forming the toner image adhere to a rotating body such as a roller or belt. A phenomenon occurs. Conventionally, in order to prevent this, a mold release layer (made of tetrafluoroethylene or silicone rubber, etc.) or a mold release liquid (silicone oil, etc.) was applied to the surface of the rotating body, but the prevention effect was It was insufficient.

In addition to this, improvement proposals are disclosed in JP-A-55-55574 and JP-A-55-96970. In this method, a bias voltage having the same polarity as the toner image is externally applied to a rotating body that contacts the toner image, or a bias voltage having the opposite polarity to the toner is applied to a roller on the opposite side of the toner image. However, when applying voltage with a corona charger such as a corotron, not only is the device larger, more complicated, and more expensive, but if the corona charger becomes dirty, spark discharge and leaks are likely to occur, resulting in poor reliability and safety. Ta.

Furthermore, when the voltage was applied using a bias roll, the practical effect was small and the bias roll was easily soiled, making it impractical.

Further, when the rollers are brought into contact with each other under high pressure and fixing is performed at a relatively high speed, the force that offsets the toner due to friction increases, which tends to cause complex changes in the electric field. Therefore, the offset prevention effect becomes unstable. Items that consume this high voltage are those that control the fixing drive, exposure lamp, etc. or heaters in addition to these within a limited power range, and because they use excess power, there are many I am forced to limit myself.

Furthermore, in the conventional method, not only the offset prevention effect was not stable, but also the toner image was scattered and the obtained image was disturbed. Therefore, when the grandchild copy was made several times, the image was often distorted.

SUMMARY OF THE INVENTION An object of the present invention is to solve these conventional problems and to provide a fixing device that has a simple configuration and provides excellent effects that could not be expected in the past. Another aspect of the present invention provides a fusing roller having anti-offset ability.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fixing device, a fixing roller, or a coating member that generates frictional electrification on the fixing rotating body used to prevent the offset phenomenon.

Another object of the present invention is to provide a fixing device, a fixing roller, or a coating member that can inexpensively and reliably reduce offset without consuming a lot of wasteful power, and can also improve the image quality of a fixed image. The purpose of

Further objects of the invention will be understood from the following description.

<Overview> The present inventors have discovered that the occurrence of offset is largely dependent on the toner's separation charging potential. Paying attention to this point, the inventors of the present invention conducted many experiments and devoted research, and as a result, they came up with the theory and solution described below.

That is, the basic theory will be explained based on FIG.

Generally speaking, when focusing on the object to be fixed such as the toner image T or resin material for coating, and the rotating body such as a roller or belt, the force acting thereon is mainly caused by the force acting on the first rotating body that comes into contact with the object to be fixed. The resultant force FA of the cohesive force F2 between the adhesive residue and the fixing object acting between the fixing objects and the adhesive force F3 acting between the fixing object and the recording material, and the force created between the fixing object and the first rotating body. an electrostatic force F4 to be used, an electrostatic force F5 acting between the fixing object and the recording material, and an electrostatic force F6 acting between the second rotating body and the fixing object that is not in contact with the unfixed object; It is broadly divided into Most of the causes of the occurrence of offset are due to the mutual frictional charging potential between the fixing object, the 1.2 rotary body, and the recording material, which are mainly caused by the force FB.

Therefore, if the total force of the electrostatic charge and the frictional charging potential mainly consisting of the force FB has a positive component force that causes the object to be fixed to move toward the second rotating body, the occurrence of offset can be largely prevented.

Since this total force can be considered to be equal to the electrostatic resultant force FB, in order to bring this electrostatic resultant force FB into an appropriate state, the present invention is characterized in that a charging agent is applied to the first rotating body or the second rotating body. It is.

Furthermore, in order to improve the offset prevention effect, the aforementioned resultant force? , and the electrostatic resultant force F′B → A charging agent is applied to the first rotary body or the second rotary body so that the resultant force FC maintains a positive force that directs the object to be fixed toward the second rotary body. It's fine to give it.

Specific examples include: (1) applying a negatively charging charging agent to the first rotating body used for a negatively charged object; and (2) applying a negatively charging agent to a second rotating body used for a negatively charged object. Applying a positively charging agent to the rotating body; ■ Applying a positively charging agent to the first rotating body used for the positively charged object to be fixed; ■ Applying a negatively charging agent to the second rotating body for the object, etc.
In order to increase the potential of the recording paper when the potential is several times that of the rotating body or during low-speed fixing, a second method is to flood the rotating body with a charging agent that is charged to a polarity different from that of the paper, and combinations similar to these may be used.

The term "application" used in the present invention refers to (1) inclusion in a rotating body (immersion, addition, mixing), (2) application (directly, by an application member, or via another rotating body). It implies that.

Furthermore, since the present invention prevents offset by charging at least one of the first and second rotating bodies, the rollers, belts, etc. involved in conveying the recording material supporting the fixing rotating body or the object to be fixed are Applicable to rotating bodies. Furthermore, it is important that the coating member itself contains a band/forming agent, since it is used for coating to electrically protect the offset.

In another aspect of the present invention, a charge-controlling mold release agent is used instead of the above-mentioned charging agent. This has appropriate charging properties like the above-mentioned charging agent, but also has mold release properties like silicone oil. Therefore, offset can be prevented to a greater extent by using a charge control mold release agent than by using a conventional mold release agent to reduce tackiness.

The present invention can also be applied to a fixing rotary body, a conveying rotary body, a coating member, etc., each of which exhibits or can provide an excellent offset prevention effect.

<Embodiments and their explanation> Hereinafter, based on the above-mentioned overview, the present invention will be further explained by giving specific examples and explaining drawings, photographs, etc.

(1) When an object to be fixed, such as a toner image or a resin body, can have a predetermined polarity, a fixing roller that is or has been provided with a charging agent in order to make the object to be fixed adhere to the recording material side; An example of a fixing device having the following is shown below.

a, FIGS. 2 and 3 show a row using a charging agent which is positively charged by friction with plain paper.

a-1 and FIG. 2 show an apparatus in which a toner image T formed by electrophotography is fixed on plain paper P by a heat fixing device.

It presses against the roller and rotates by sliding. This heating roller 1i
1. A heat-resistant releasable resin layer 11 such as tetrafluoroethylene resin is provided on the outer peripheral surface of a hollow roller core 12 made of metal such as aluminum, stainless steel, or copper to a thickness of 20 to 100 μm.

The pressure roller 22 rotates around a bearing (not shown) and comes into pressure contact during fixing, and an insulating elastic layer 2z of silicone rubber, furan rubber, fluorosilicone rubber, etc. is attached to the outer periphery m of the metal roller core 2I with a temperature-sensitive material such as an electrocouple. The element 4 is placed in contact with it (by controlling the output of the heater 5 or the applied voltage, etc.)
The toner image is maintained at the melting temperature.

51.52Fi This is a separating claw that reliably separates the recording material from the roller after fixing. 7 is a heat-resistant non-woven fabric impregnated with an electrostatic property, and at the beginning of 6, the pressure row 22 starts to press and rotate, but then comes into contact with the heat-resistant non-woven fabric impregnated with an electrostatic agent, and the electrostatic agent is applied. applied to its surface.

After copying is completed, the pressure row 22 contracts again due to natural heat dissipation and separates from the heat-resistant nonwoven fabric. This made it possible to minimize thermal deterioration of the charging agent.

The chemical formula of the charging agent used in this example is shown.

1. Fatty acid monoethanolamide (R-QC)-NH-OH20H20H For example, R is C14, C, lauric acid, etc.; Fatty acid jetanolamide, R is C, , C4, lauric acid, etc. As a result, the pressure roller becomes positively charged due to friction with the plain paper and the fixing roller 2.

In the fixing device configured as described above, the outer diameter is 60 mm.
A pair of mm rollers are brought into contact with each other with a total pressure of 60 kg, and A3
Size paper 23 sheets/min (roller circumferential speed 270 ztn/s
Copying was performed at a speed of ec). Using a negatively charged toner (negative toner), we fixed 1,600 square meters of toner on one sheet of A3 plain paper.Compared to when no charging agent was applied, with the charging agent of ■, the toner was 1/1
5 or less, and with the charging agent (3), it decreased to 1/20 or less.

Also, the pressure roller potential after paper feeding is +400 with the charging agent (■).
07. With the charging agent II, the voltage was +4,500 V, and the effect of the charging agent is clear compared to 16,000 V or more when no charging agent is applied. This phenomenon can be considered as follows. When a positive latent image is transferred to plain paper after being developed with negative toner, the plain paper is given a positive charge and is transferred due to the attraction of the negative toner. That is, it is important that the plain paper is positively charged at this point. However, during the fixing process, the pressure roller and the paper passing through the paper are charged by frictional peeling, and the pressure roller becomes highly charged.
Plain paper will be charged in the opposite direction to the charge it holds.

The inventors believe that the offset is related to electric potential rather than the amount of charge, and a pressure roller with a small amount of this phenomenon has a much higher electric potential than the surface paper, and exerts a large force on the negative toner on plain paper. This is because it will have a negative impact.

Next, in order to examine the sustainability of the above effect, we
A heat-resistant non-woven fabric with a thickness of 0'm1n and 2 mm was provided over the entire length (320 mm) of the pressure roller, and the heat-resistant non-woven fabric was impregnated with 10 CC of methyl silicone oil containing 3q6 of the charging agent I, and under the above conditions. When we performed intermittent copying of 1 sheet per minute for 10,000 sheets, we were able to confirm that even after 10,000 sheets, the same effect as the above result was obtained.

Furthermore, methyl silicone oil containing 30% of charging agent I was used.
Even after applying 5 CC uniformly to the pressure roller surface, removing the charging agent application member 6゜7 shown in Figure 1, and performing intermittent copying similar to the above for 2000 sheets, the effect was still slightly low F. However, it was confirmed that the offset was reduced to 1/12 of that of the conventional method.

a-2. Another embodiment is an image forming apparatus that develops and visualizes various N-type negative latent images with positive toner (FIG. 5 shows the fixing roller of this embodiment used and the fixing device having the same).

As No. 29, a silicone rubber sponge 91 with a wall thickness of 4 mm and a sponge hardness (ASKERC) of 25 degrees is coated on an aluminum core bar with an outer diameter of 14 mm, and a heat-vulcanized silicone rubber coating 92 with a wall thickness of 1 myin is coated around the outer periphery. 1. Using a roller with an outer diameter of 24 ui+, pressure was applied at a total pressure of 5/q. Copying was carried out on A4 size paper at a roller circumferential speed of 60 am/sec.

Further, 5 is a heater, 4Vi nermistor, 12 is a cleaning member such as Nomex, 51t52 is a separating claw, and the supporting member 6 and a heat-resistant nonwoven fabric are impregnated with a diaphragm agent applicable to the present invention.

In this embodiment, the method of applying the charging agent and the like are the same as in the previous embodiment. In this example, the charging agent (I, II above)
By applying this, it was possible to reduce the offset to 175 pieces, which was the conventional offset amount. In this case, the pressure roller surface potential, copy paper potential, and fixing roller potential are +JOOVl and -400V, respectively.

-20 ■. In this embodiment, although the toner subjected to the electrostatic force has a positive charge, the same offset prevention effect as in the previous embodiment can be obtained because if the potential of the pressure roller is low, the distance to the toner is is further away from the paper, so even if the paper potential is smaller than the pressure roller potential in absolute value, if the difference is about twice that, it will be affected by the paper potential near the toner.

The effect of the charging agent in this embodiment is that the pressure row 2 is positively charged due to friction with the paper. Namely, 1. If you look at it from the opposite perspective, the paper becomes meiosally charged, so the electrostatic attraction force of the paper itself to the positive toner increases.

As mentioned above, in this example, a1 is a simple method of applying a positive charging agent such as a charging agent containing fatty acid monoethanolamide or fatty acid jetanolamide to the surface of the rotating body. It is possible to maintain a stable state of a recording material such as paper or a fixing object, and to reliably prevent an offset phenomenon. Further, the present invention is effective for a fixing device having a rotating body with an insulating coating, and is particularly effective for a fixing device that has a large amount of frictional charge at the nip portion and uses negative toner, or a fixing device that has a relatively small amount of friction band thread. Effective for fixing devices that use positive toner.

Note that this embodiment is not limited to a fixing device equipped with a rotating body such as a roller or belt having an insulating coating;
Preferably, it is applied to the surface of a thick insulating coating layer.

Although this embodiment is particularly effective for heat fixing devices, it can also be applied to pressure fixing devices.

4 and 5 show examples in which a charging agent that is positively or negatively charged by friction with plain paper is used so that the object to be fixed is held on the plain paper side. Incidentally, since FIGS. 4 and 5 have the same drawing numbers as the above-described drawings of FIGS. 2 and 5, respectively, only the different parts will be explained below.

b-1, FIG. 4, and FIG. 5, the heat-resistant nonwoven fabric 7 and support member 6 of FIG. 2 and 6 C are omitted.

A fixing roller 1 has a heating heater 3 such as a halogen heater inside, and rotates in the direction of the arrow in response to driving force from a drive motor (not shown). Reference numeral 2 denotes a pressure roller incorporating a low-heating heater 6' having a lower output than the heater 3, which presses against the redundant row 21 and rotates slidingly.

Reference numeral 16 denotes a cleaning member for removing foreign matter such as offset toner and paper powder adhering to the surface of the fixing roller from the roller surface, and uses a cleaning web 61 made of heat-resistant nonwoven fabric such as Nomex or Himeron.

The cleaning web 61r/'i is brought into contact with the fixing roller by a pressing roller 65 having elasticity such as silicone rubber, fluorosilicone rubber, fluorosilicone rubber, or silicone rubber sponge. Further, this web 61 is moved from the supply row 262 by a driven take-up roller 65 so as to change its contact position little by little, so that the new portions t and im of the cleaning web 61 are always brought into contact with the fixing roller.

This embodiment focuses on objects to be fixed such as the toner image T and resin material for coating, and rotating bodies such as rollers and belts, and as shown in FIG. Adhesive force F1 acting between objects to be fixed and cohesive force F between objects to be fixed
2 and the adhesive force F3 acting between the object to be fixed and the recording material, and when this resultant force FA directs the object to be fixed toward the first rotating body, the object to be fixed and the first rotating body An electrostatic force F4 acting between the fixing object and the recording material, an electrostatic force F5 acting between the fixing object and the recording material, and an electrostatic force F6 acting between the fixing object and the second rotating body that is not in contact with the unfixed object. This is to prevent offset by increasing .

Specifically, the sum of the resultant force FA and the electrostatic resultant force F'B is
Offset is caused by facing toward the first rotating body on the side of the object to be fixed, and offset is prevented by facing toward the second rotating body on the opposite side of the object to be fixed.

In this embodiment, even if the configuration is simple and does not include a special charge applying device from the outside, the first rotating body such as a fixing roller or a belt, the second rotating body such as a pressure roller or a belt, and copy paper can be used. By selecting the friction banding acid series of each recording material such as, etc., and applying it to the fixing device of various image forming apparatuses,
Even in the fixing device having this configuration, by selecting the triboelectrification series of the three members mentioned above, the direction of the vector of the sum of the resultant force F and the electrostatic force FB is always directed toward the second rotating body. This makes it possible to minimize the occurrence of offset phenomena.

[Example 1] Now, S. A positive latent image is formed on a P-type photoreceptor such as, this positive latent image is developed and visualized with a negative toner, and then the negative toner image T is transferred to plain paper P. Thereafter, the copy paper P carrying the toner image T is guided by the guide plate 7 toward the fixing roller 21 side.

As the above-mentioned pressure roller 2, the following F was manufactured so that the frictional electrification series with respect to copy paper was positioned in a more positive order.

Nippon Anilosil Co., Ltd.'s AERO8-L is a commercially available fine silica powder used as a filler in unvulcanized silicone rubber.
Silane coupling agent containing ami7 group at 2[)0 (
Structural formula: % formula%
Parts by weight were mixed and thoroughly kneaded together with a vulcanizing agent to form an unvulcanized rubber sheet.

The unvulcanized rubber sheet described above was prepared after being left at room temperature for 3 days. After a stainless steel core with an outer diameter of sown was subjected to a blast treatment, an adhesive was applied thereto, and the material was left for 5 hours at 25'C, and then baked at 120C for 20 minutes.

The core metal is covered with the unvulcanized rubber sheet, and the pressure is 150.
Post-vulcanization was carried out at kg/cIIL2 and a temperature of 170C for 30 minutes. (Using a press vulcanizer) Furthermore, after 4 hours of secondary vulcanization at 200 mm, the outer diameter was 59.
．． It was ground to 5 mrn. Then the roll 1180D
Dimethyl silicone oil (viscosity at 25υ is 10
0csO) for 48 hours to swell,
Finish polishing the outer diameter bomy and use it as a pressure roller.

The rollers are at a more positive position in the triboelectric series compared to copy paper.

Furthermore, the above-mentioned filler also acts as a reinforcing filler for the rubber material, allowing the pressure roller to have extremely high physical properties.

Further, the fixing roller 1 is a roller having an outer diameter of 60 mm and a wall thickness of 7 mm, with a PFA coating of 30 μm thick on top of the aluminum core metal, and the pressure roller 2 is a roller with an outer diameter of 60 mm and a wall thickness of 5 mm. Using a roller coated with heat-vulcanized silicone rubber, apply pressure at a total pressure of 60 to 9.
5 size paper 26 sheets/min (roller circumferential speed 270 nu/5e
Copying was performed at speed c). As a result, the surface potential of the pressure roller after 99 sheets were continuously passed was +3000 to +42.
00V, the potential of the copy paper was +270V, and the surface potential of the fixing roller was -50 to -70V. That is, it faces toward the pressure roller.

Therefore, toner offset to the fixing roller was extremely small, and very good results were obtained.

[Example 2])-2. The fixing device of the present invention, which is used in an image forming apparatus that forms a negative latent image on various opcON type photoreceptors and visualizes this negative latent image by developing it with a positive toner, was used in the fifth embodiment. As shown in the figure.

The pressure roller 9 is a roller with an outer diameter of 24 mm, which is coated with a heat-curable silicone rubber coating 92 of 1 mm thick containing sponge hardness (ASiRO) powder of 4111711% on an aluminum cored metal with an outer diameter of 1412 + π. A4 size paper was copied at a roller circumferential speed of 60 tnm/θec by applying pressure at a total pressure of 5 kg.

After passing one sheet of paper, the surface potential of the pressure roller was +7 oOv, the potential of the copy paper was -200 ■, and the surface potential of the fixing roller was -30 to -40 ■. In other words, the electrostatic force is directed toward a certain pressure roller, and F6 is directed toward the fixing roller, which is preferable for offset. However, since F5 is a more dominant region than F6, toner offset to the fixing roller is extremely very good results were obtained.

<Comparative Example> A product was manufactured. The manufacturing method includes the pressurizing port in the forward order.
・It is exactly the same except that the filler was changed.

As a filler, commercially available AjiiRO8-L2 is used.
A mixture of 20 parts by weight of 00 and 100 parts by weight of unvulcanized rubber was used.

The pressure roller after molding and vulcanization is at a more negative rank in the triboelectrification series compared to copy paper.

(Comparative Example 1) An image forming device and a fixing device were used which were exactly the same as in Example 1, except that heat-vulcanized silicone rubber, which has a more negative triboelectrification series than the copy paper, was used as the pressure port 22. A similar paper passing test was conducted using After passing 99 sheets, the surface potential of the pressure roller was more than 16 ooov'F (the absolute value is negative in the negative direction), the potential of the first copy paper was +500 V, and the surface potential of the fixing roller was -50 to -70 V. Ta. That is, among the electrostatic forces, F4 and F5 face the pressure roller side, which is a favorable direction for offset, and F6 faces the fixing roller side, which is unfavorable for offset, and F6 is more dominant than F5. As a result, toner offset occurred to the extent that the cleaning web 61 could not be cleaned, resulting in poor copy quality.

(Comparative Example 2) A similar paper passing test was conducted using a fixing device that was exactly the same as in Example 2, except that negative-rank room-temperature vulcanizable Crecon rubber was used as the pressure roller.

After passing one sheet of paper, the surface potential of the pressure roller is -800■, the potential of the copy paper is +180■, and the surface potential of the fixing roller is -5
The voltage was 0 to -40V.

And there were a lot of offset toners.

Table 1 shows the amount of offset toner in each of Example 1, Comparative Example 1, Example 2, and Comparative Example 2. The amount of offset toner was expressed as a weight ratio (%) to the total amount of toner on the copy paper.

From Table 1, in Example 1, the toner offset could be reduced to 1/20 of the toner offset amount of the conventional example (Comparative Example 1).

Furthermore, in Example 2, the toner offset could be reduced to 215, which is the toner offset amount of the conventional example (Comparative Example 2).

The reason for the above effect will be explained.

As described above, this occurs when the toner aura faces toward the fixing roller, so in order to prevent toner offset, it is sufficient to direct the toner toward the roller.

In the above embodiment, the friction zone and section series between the pressure roller and the copy paper were changed by adding a filler to the pressure roller, so F5 and F6 were mainly changed. It is.

That is, due to friction and peeling electrification between the copy paper and the pressure roller, a negative charge is applied to the copy paper, while a positive charge is applied to the pressure roller.

Since the copy paper is closer to the toner image than the pressure roller, the absolute values of the charged potentials of the copy paper and the pressure roller 2 are the same, or the pressure roller is several times larger. It was experimentally confirmed that when F5 is present, F5 is dominant.

That is, when the potentials of the copy paper and the pressure roller satisfy the above conditions, the present invention is very suitable when applied to an image forming apparatus using positive toner as in the second embodiment.

A fixing device that satisfies the above conditions may be, for example, a so-called low-speed image forming device that has a slow constant flight speed and a low total pressure, or a fixing device that is high speed and has a low height. next,
The charged potential of the pressure roller is 1 compared to the potential of the copy paper.
It has been confirmed through experiments that when the magnification is approximately 0 times or 10 times or more, F6 becomes dominant in toner offset to the fixing roller.

That is, when the absolute value of the potential of the pressure roller is overwhelmingly larger than that of copy paper, it is very suitable when applied to an image forming apparatus using negative toner as in the second embodiment.

Other Comparative Examples Next, a test was conducted in exactly the same manner as in Example 1 except that an N-type photoreceptor, that is, a positive toner was used. When the pressure roller located at the front of the copy paper was used, the offset was extremely reduced, whereas when the pressure roller was located at the front of the copy paper, the offset increased.

Similarly, when a P-type photoreceptor was used in Example 2, when a pressure roller positioned in a negative order relative to the copy paper was used, the offset was extremely reduced.

These results also have the same meaning as the above results.

As described above, in the above embodiment, the offset can be minimized with a simple configuration even without a means for applying an electric charge to the fixing roller or the pressure roller from the outside.

In this embodiment, a particularly effective example was shown in which the frictional charging series of the pressure roller was changed.
By changing '6, the direction of the vector of the resultant force F may be directed toward the pressure roller side.

A more effective method is to change the triboelectrification series of surfaces that are likely to be charged to a high potential (for example, surfaces with a large coefficient of friction).

In the configuration of the embodiment, the pressure roller is most likely to be charged to the highest potential due to static characteristics. Therefore, let us consider an example of a pressure roller that is positioned in a positive or negative order in the frictional charging series with respect to copy paper. If the elastic layer of the pressure roller is made of silicone rubber, and if general fine powder silica is added to the silicone rubber as a reinforcing filler, most of them will be negative to paper, that is, they will be different from copy paper. Due to frictional charging, the pressure roller is negatively charged (therefore, the copy paper is positively charged).

<Group 1 of Charging Agent Examples> The fine silica powder includes dry process silica (fumed silica) and wet process silica. Specifically, commercially available dry process silica is Nippon Aerosil Co., Ltd.'s product name A [RO8 Engineering L 130,
200°300, 380. TT600. MOX80.
MOX170. (1!0K84 iC! ABOT product name, Cab -0-1311N5.MS-7゜MS
-75,I(S-5,1-5i W,AC!KJluR-OHjiiM 工j!i GMB
Product name of Company H: WackerHM N20. V15. N2
0ffi, T+0. There are products such as D-O Fine Silica (trade name) manufactured by Konig Company; and F'ranso 1 (trade name manufactured by Fransi 1 Company). Commercially available wet process silicas include (list the product name on the left and the sales company name on the right) Carplex, Shionogi & Co. Nip Seal, Nippon Silica Toxeal, Fine Seal, Tokuyama Soda Vita Seal, Taki Hijiruton, Silnetx, Mizusawa Kagaku Starsil
Divine Chemical Himezil
Ehime Pharmaceutical Thyroid Fuji Depison Chemical H1-Day 11 Pitt
sburgh Plate GlassOo.

(High Seal) (Pittsburgh Plate Glass) D
urOsil Fillsto
ff-Gesellschaft (Douroseal)
MarquardUltrasil
(Fürstsf Gusel Shaft (Ultra Seal) Markorth) ManOsi'l
Hard + nan ana Ho1a
en (Manoseal) (Hardman and Holden) Hoesch Ohemisc
he Fabrik Hoesch
K-G) (Hiemitsusche Fabrik Herash) Sin-8tone 5
toner Rubber Cjo.

(Unru Stone) (Stoner Rubber) N
alco Na1co Ohem, O
o.

(Nalco) (Nalco Chemical) Q,
uso Ph1ladelphia
Quartz Cjo.

(Shoes) (Philadelphia Quartz) Santocell Monsant
o-Chemical Cjo.

(Santocell) (Monnanto Chemical) ■mail
Engineering 1linois MLnera
lθ Co.

(Imusil) (Illinois Mineral) Calcium
5ilikat Ohemische Fabr
ik Hoesch (calcium silicate) K-G (Hoesch) Oa181:
L Fillstoff-()es
ellschaft (Kargil) Ma
rquart Fortafil engineering imperial
C! chemical (forta file) engineering n
industries, Ltd.

(Imperial Chemical Industries) MicrOcal Joseph
0rosfield k 5oz.

(Microcal) Lta.

(Jiecef Crossfield Andnans) Manosi'l Hardman
and Ho1den (Hardman and Holden) Vulkasil,
Farbenfabriken Bryer.

(7”yv kazir) A, -G.

(Falpen 7 Appli Kembaya → Tufknit Durham Che
mical8. Ltd.

(Toughknit) (Doulham Chemicals) Silmos Shiraishi Kogyo Starex Shinshin Kagaku Fricon Le Takiki Fertilizer, etc.

All rotating bodies such as belts and lawns to which fine silica powder is added are ranked negatively in the friction band series compared to paper as a recording material. When added to rubber, the amount added is preferably 6 to 50 parts by weight per 100 parts by weight of rubber.

By adding the above silica fine powder to a rotating body, a large negative surface potential can be generated on the rotating body by frictional brazing with paper. This is effective for the pressure roller 22 for positive fixing objects and for the fixing roller 21 for negative fixing objects.

<Charging agent example group 2> Those suitable for the above silane coupling treatment are those of the general formula % (Ri alkoxy 7 groups or chlorine atom, m is an integer of 1 to 3, Yi amino group, vinyl group, glycidoxy group, mercapto A silane coupling agent represented by a hydrocarbon group containing at least one or more of a group, a methacrylic group, and a ureido group (n is an integer of 6 to 1) is suitable.

By applying this silane coupling treatment to the rotating body, the more the rotating body generates a large positive triboelectric charge due to friction with the paper, the more positively the rotating body is positioned than the paper in the triboelectrification series.

For example, materials that can be subjected to silane coupling treatment, such as fine silica powder (dry method or wet method) that has been subjected to this treatment and added to the surface of a rotating body, or a silane coupling agent applied to the surface of a rotating body. For example, as a compound containing a vinyl group, H2C=CHB101°H,02CHEIi(OC2Hρ3 H2C=OHC!1(2EHCI).

H2O=CH0f-[2Si(OH5)C12H2C=
CHCH2S1(CH3)2CIH2C:C! HOH2
8i (002H5).

H2(3:0H8i(0(32H40CH,).

(H20: (!HOH2)2SiOJ2(H2C=CH
)281(OC2H6)2L:H2C=CH)3s:t
oc2H5H2C=OH+0H2(!H2S i (0
0)11. Examples of compounds containing glycidoquine groups include 0H2-C! HOH20CH2C! H2OH2Si
(0,C!HS-containing\1 As for those containing mercapto group, HBCH2CH
20H2Si(OCH3).

H8C! H2CH2C! H2S1 (002H5-containing methacrylic group is OH.

(H3C)2C=C-000CB2CH2CH2SIC
IJ2(3H3 (H,c)2c!=C!-C00cH2(!H20I
(2Si(OCH3 people OH5: [(2C:0-000CH20H2CH2Si(QC
! Examples of those containing a H3)3OH3 ureido group include H2N0ONHOH20H20H28i (002H5).

Particularly preferred seven-run coupling agents for use in the present invention are compounds containing an amino group and are represented by the following structural formula.

H2NC! H2OH2C! H281 (OCH3).

H, N0H20H2CH281 (002H5).

Oh.

H2NOH2CH20 to 5i(OCiH3)2H5 ■ H,N0H20H2NHOH20H20H2Si(OC
H3)2H2N00H'klCH20H20H2Si(
002H5) 3H2No Horse C Horse NI (OH20H20H
2Si(00)(,).

H2Non2CH2NHOH20)12N)i0n20
H20H2Eli (00 horse) 3H502ococH20
'H2NHI2an20)12S1(ocH5peopleH3
O2000(1!)120H2N)ICH20H,NH
C! H20, H2OH2S1 (QC! remaining) 3H5C20
000H2(3H2NHOH2CAI2NHCH20H
2NHOH20H, NH・0H20B20B28i (0
(1!H,)3H30000CH20H2NHOH20
H2muH('H2OH2OH2S1(OCH3).

H2NOH20H2NHOH2kai0H20H2Si(0
08 pieces H2NCH2CH2NHCH2 meeting CH2CH25
i(Of:H3peopleH, (3NHOH20H2Cn, s
i (oo2H5 peopleH2N(OH20H2NH)20H
20H20) i2si(oo=, ).

H30-NHoON) (03H6Eli (QC!H5)
.

Examples include. Further, the alkoxy group of the above compound may be a chlorine atom. These 7-rank compres- ing agents may be used alone or in a mixed system of two or more.

As another example, felt may be impregnated with a positive charging agent such as the aforementioned fatty acid monoethanolamide or fatty acid jetanolamide, and then applied constantly or intermittently to the surface of the silicone rubber row 2. Even if the pressure roller is charged positively.

As described above, by applying a pressure roller having a negative surface or a positive surface to the fixing device so that the vector of low profit F of the force acting on the toner always faces the pressure roller side, O. A stable fixing device is obtained.

In addition, even in cases where it is difficult to apply a roller surface potential externally, by setting a suitable triboelectric charging system that requires a special voltage application means from the outside such as a corona charger or a bias roller, the present invention can be used, for example, at a high potential. can also be easily achieved.

The above example shows a heat fixing device that works most effectively, and in that case, the offset due to large stickiness when toner is melted can be minimized based on the above configuration and technology. It can also be applied to fixing devices that perform coating processing, and can also be applied to pressure fixing devices.

Also, in the above example, in an apparatus that fixes a fixing object by sandwiching and conveying a recording material between two rotating bodies (belt, roller 2, etc.), the rotating body with the smaller capacitance IC of the two rotating bodies, For example, if the diameter is the same and the dielectric constant is the same, it is preferable to apply it to the rotating body with a thicker insulating layer, in other words, the charging potential tends to be high, and to the side of the rotating body that does not come into direct contact with the toner image. It is more preferable to apply

b-31 In this example, as shown in 1)-1 [Example 1] and b-2 [Example 2], a positive or negative triboelectric charging agent was applied to the surface layer of a rotating body for fixing. It is characterized in that it is contained therein. In particular, in this example, a material containing fine silica powder treated with a silane coupling agent represented by RmSiYn which has a high positive charging effect is used.

Note that this embodiment is completely the same as [Embodiment 1], so the explanation will be omitted.

To summarize the features of this example, there is provided a fixing device and a fixing rotating body, which have first and second rotating bodies that sandwich and convey a recording material, and fix an object to be fixed on the recording material between the rotating bodies. The first rotating body has a surface containing a material that is positively charged (negatively charged in the latter example) due to the friction zone with the recording material, and offsets the fixing object to the first and second rotating bodies. The present invention provides a fixing device and a fixing rotating body that are characterized by preventing this phenomenon.

The effects of this example are as described above.

Although the above example uses a positive belt, it is possible to obtain a rotating body with a positive belt by incorporating the above-mentioned fine silica powder into the first rotating body.

The silica fine powder is shown in the above-mentioned Charging Agent Example Group 1>, but the meaning of the phrase silica fine powder will be explained here.

Simply defined, this is just one line of negative and negative ingredients.
The present embodiment includes all methods in which a negatively charging agent is applied to the rotating body to maintain the rotating body at a high potential for a long period of time in order to positively charge the rotating body negatively.

The dry method silica is a method that utilizes, for example, a thermal decomposition oxidation reaction of silicon tetrachloride gas in an oxyhydrogen flame, and the basic reaction formula is as follows.

5iO7i4+ 2H2+ 02→SiO□+4HOl
In addition, in this manufacturing process, it is also possible to obtain a composite fine powder of silica and other gold maple oxides by using other metal halide compounds such as aluminum chloride or titanium chloride together with a silicon halide compound. Also includes.

The particle size is desirably within the range of 0.001 to 2μ, particularly preferably 0.002μ as the average primary particle size (L).
It is preferable to use silica fine powder within the range of ~0.2μ.

The wet method is a method in which, for example, sodium silicate is neutralized with an acid, and the basic reaction formula is as follows.

Na20m5iO□+H(J+H2O-+5iO2nH
, O+NaO, J acids include, in addition to hydrochloric acid, sulfuric acid, nitric acid,
Phosphoric acid, carbon dioxide gas, sulfur dioxide gas, etc. are used.

Conventionally, silicone rubber etc. become negatively charged due to friction with paper, but as they are used, their surface potential decreases to F.
The present inventors have discovered that as this progresses, positive charging may occur. In other words, conventional silicone rubber has a very large potential change and cannot provide a stable offset prevention effect.

On the other hand, in the above embodiment, by applying a positive or negative charging agent to the insulator such as silicone rubber, the surface potential is stabilized at a predetermined potential, and the potential is high enough to have an offset prevention effect. can be maintained over a long period of time.

b-43 This embodiment is characterized by the use of a polarity-changing charging agent that reverses the characteristic of a negatively frictionally charged rotating body, such as a rubber roller, to positively frictionally charges it. An example of this is shown in F below, but the key point is that the surface of the rotating body, which has characteristics that have an adverse effect on preventing the offset of toner and other objects to be fixed, is treated with a polarity-changing charging agent such as the silane coupling agent. It consists in adding or having been added.

This embodiment also focuses on using F5 and F6 of the static air forces to effectively prevent offset.

A method for manufacturing a roller that can be applied to the present invention will be described.

AffRO8-L from Nippon Aerosil Co., Ltd. is a commercially available fine silica powder used as a filler in unvulcanized silicone rubber.
200 was mixed with 100 parts by weight of unvulcanized rubber, thoroughly kneaded with a vulcanizing agent to form an unvulcanized rubber sheet, and this unvulcanized comb sheet was left at room temperature for 3 days. Prepared.

Next, use a stainless steel core metal with an outer diameter of 50 mm).

After last processing, apply adhesive and heat in 25C environment.
It was left to stand for a while and then baked at 120C for 20 minutes. After sowing, the core metal was covered with the unvulcanized comb sheet, and the pressure was 150 kg/CML2 and the temperature was 17.
Secondary vulcanization (using a press vulcanizer) was performed at 0C for 30 minutes, and then secondary vulcanization was performed at 200C for 4 hours, followed by grinding to an outer diameter of 59.5 mm.

Next, the roll was immersed in 180C dimethyl silicone oil (viscosity at 25υ: 100cm) for 48 hours to swell, and then finished polished to an outer diameter of 60mm to form a pressure roller. .

Compared to copy paper, the above rollers are frictionally charged,
Therefore, it is placed in a negative ranking.

This example uses a silane coupling agent containing an amine group (structural formula: H2tJan2 (H2an2
si(oan3)5) was dissolved in toluene and applied to the surface of Row 2, and then heated in an oven of 140 tons for 60 minutes.
The material was left to dry for a minute. A roller whose surface layer has been subjected to a ring treatment containing amine groups will be positioned more positively in the friction magnetization series than copy paper. The preferred silane coupling agent for changing Row 2 from a negative rank to a positive rank for paper in the Yazuri Teiden series is as described above.

The fixing device of this embodiment to which the above-mentioned roller is applied will be briefly described using a specific example.

[Example 3] A positive latent image was formed on a P-type photoreceptor such as Se, and this positive latent image was developed with a negative toner, using the silane coupling roller having an outer diameter of 60 lines that can be applied to the present invention, Total pressure bo
Copying was carried out at a speed of 26 sheets/min of A5 size paper (roller circumferential speed 270 mm/sea).

The surface potential of the pressure roller after continuously passing 99 sheets is +3200
~+5800V, the potential of the copy paper was +260V, and the surface potential of the fixing roller was -50 to -70V.

Further, toner offset to the fixing roller was extremely small, and very good results were obtained.

[Example 4] A negative latent image was formed on an N-type photoreceptor of various OPCs, and this negative latent image was set to -29 with a positive toner, and the outer diameter was 14 m.
m wall thickness 4" on aluminum core metal, sponge hardness (ABKE)
RO) Covered with 25 degree silicone rubber sponge 91,
The outer circumference was subjected to the silane coupling treatment applicable to the present invention (Aerosil 200 (02H5) 2N-
0,H65i (processed with 0 (3H, included)) Using a roller with an outer diameter of 24 mm and coated with 7 recon rubber with a thickness of 1 mm, A4 size paper was pressed at a total pressure of 5 Icg. Copying was performed at a roller circumferential speed of -60 mm/sec.

After passing one sheet of paper, the surface potential of the pressure roller is +650V, and the potential of the copy paper is -300V.

The surface potential of the fixing roller was -30 to -40V. Further, toner offset to the fixing roller was extremely small, and very good results were obtained.

[Comparative Example 3] As the pressure roller 22, a roller before being treated with the above-mentioned amino group-containing γ-lan coupling agent, that is, a roller made of silica fine powder (Aerosil), which is commonly used in the past.
200 parts by weight of silica fine powder treated with hechinamethyldisilazane to make it hydrophobic) were added to 100 parts by weight of rubber.The same procedure as Example 1 was repeated except that heat-vulcanized silicone rubber was used. A similar paper passing test was conducted using a similar fixing device.

The surface potential of the pressure roller after passing 99 sheets is -6GQOV
Above (large absolute value, negative direction), the potential of the copy paper is +3
00V, and the surface potential of the fixing roller was -50 to -70V. Then, toner offset occurred in the cleaning web 61 to the extent that it could not be cleaned, resulting in a low F copy quality.

[Comparative Example 4] As a pressure roller, a roller before being treated with the above-described amine group-containing 72-coupling agent, that is, a roller made of silica fine powder (Aerosil 200) commonly used in the past.
A similar sheet feeding test was carried out using the same fixing device as in Example 2, except that a room temperature vulcanized silicone rubber containing 20 parts by weight of C20 (Hexame powder) was added to each part by weight of the rubber. I did it.

The surface potential of the pressure roller after passing one sheet is -800V,
=r Heating row 1: +70 V, and the surface potential of the fixing row 2 was -60 to -40 V.

Furthermore, there was a large amount of offset toner.

Table 2 shows the amount of offset toner in each of Example 1, Comparative Example 1, Example 2, and Comparative Example 2. Offset toner fu Weight ratio to the total amount of toner on copy paper (
H).

Table 2 From Table 2, it can be seen that in Example 3, the toner offset can be reduced to 1/15 of the amount of toner offset in the conventional example (Comparative Example 5).

Further, in Example 4, the toner offset could be reduced to 6/11 of the toner offset amount of the conventional example (Comparative Example 4).

The reason for the above effect will be explained.

As mentioned above, toner offset to the fixing roller is
This occurs when the direction of the resultant force of F is directed toward the fixing roller, so in order to prevent toner offset, it is sufficient to direct the direction of the resultant force of F toward the pressure roller 2 side. In this example, the frictional charging series between the pressure roller and the copy paper is changed by adding a filler to the pressure roller, so F5 and y6 are mainly changed.

That is, due to friction and peeling electrification between the copy paper and the pressure roller, a negative charge is applied to the copy paper, while a positive charge is applied to the pressure roller. Since the copy paper is closer to the toner image than the pressure roller, the absolute values of the charged potentials of the copy paper and the pressure roller are either the same, or the pressure roller is several times or less. Experiments have confirmed that F5 is dominant when

That is, when the potentials of the copy paper and the pressure row 2 satisfy the above conditions, the present invention is very suitable when applied to an image forming apparatus using positive toner as in the second embodiment. For example, a fixing device that meets the above conditions has a slow fixing speed.
In addition, there are so-called low-speed image forming devices where the total pressure is low, and even when the pressure roller is at high speed, the thickness of the elastic layer of the pressure roller is very thin, and even if the triboelectric charging series increases, the triboelectric charging potential is low. is possible. Next, when the band at position of the pressure roller becomes about 10 times the potential of the copy paper, the toner offset to the fixing row 2 becomes dominant at F6 (
2) was confirmed through experiments.

That is, when the absolute value of the potential of the pressure roller is overwhelmingly larger than that of copy paper, it is very suitable when applied to an image forming apparatus using negative toner as in Example 2.

Fixing devices that meet the above conditions are used, for example, in so-called high-speed image forming devices that have a fast fixing speed and high total pressure, or that have a pressure roller that is relatively thick and has a small capacitance, so it is not possible to use a high potential. There may be cases where this is likely to occur.

In the above embodiment, a pressure roller positioned in a more positive order in a frictional charging series is used for copy paper, and this pressure roller is applied to a fixing device of an image forming apparatus having a negative image or a positive image. , it was possible to minimize toner offset due to electrostatic force with a simple configuration.

The following embodiments are characterized in that, among charging agents, a charge-controlling mold release agent that also has mold release properties is applied to a rotating body, or in a coating member for applying the charge control agent.
This corresponds to the second invention of the present invention.

In particular, the present invention can improve the appearance of the fixing object by preventing it from scattering, and can also prevent the offset phenomenon.

Next, an example of a charge control mold release agent will be given, and an example using the same will be described based on the drawings. As mentioned above, the charge-controlling mold release agent referred to in the following explanation includes those in which a charging agent is dispersed, mixed, or chemically bonded in a mold release liquid (typical example is silicone oil), as well as the following: Including those listed above, and further including everything similar to the technical idea of the present invention.

Group 1 of Examples of Charge Controllable Release Agents> Below, charge control release agents that are ranked higher than recording materials in the triboelectrification series are listed. As the charge control mold release agent, (1) dimethyl silicone oil in which some of the methyl groups are replaced with amino groups (hereinafter referred to as amino-modified silicone oil) can be used.

An example of the skeleton structure of amino-modified silicone oil is shown below.

(1) Type A (ii) Type B
1 (both manufactured by Shin-Etsu Chemical Co., Ltd.), and product name 5F8417 (manufactured by Tone Silicone ■). An example of type B is the product name KF393. KF857. KF859 (all manufactured by Shin-Etsu Chemical), etc.

In addition to dimethyl silicone oil, release agents such as methylphenyl silicone oil are suitable for those undergoing amino modification and can be used in this example.

In addition, as silicone oils having amine groups, amide-modified silicones (for example, KF3935゜Shin-Etsu Chemical Co., Ltd. brand name) and silicone diamines (for example, X-22-161,
Shin-Etsu Chemical Co., Ltd. (trade name) etc. can be used.

(2) In addition to the above examples, there may be mentioned a charge control mold release agent obtained by treating silicone oil with the following amine group-containing silane coupling agent.

H2NOH20H20H2Si(OCH3).

H2NOH20H20H2611 (QC!2H5)3C
H.

H2NOH20H2CH2Si(QC!H3)2H3 H2NC! H2C! H2NHOH2(H20H2Si(
QC! H,)2H2NOONHCH20H2C! H2S
1 (002H5)3H2NoH20H2NHOH20H
20H2Si (OCH,)5H2NCH2CH2NH
CH2CH2NHCH2CH2CH2S1 (OCH5)
3H5020000H20H2NHCH20H2C3H
2Si (OCH5 people H5C20000H20H2NHO
L, OH,, NHOH20H20H2Si (OClis
)3H5020CiOC)I2(IH2NH(!H2(
! H2NHC! H20H2NHC! H20H2NH・0
H20H20H2Si(OCH3).

H,00000H20H2NHOH20H2NH(3H
20H2(3H2Si(0(!) into H2N0!H20H
2NHOH2()OH2CH2si(ocu, ).

H3ONHOH20H20H2S1(002H5)3H
2N(OH20H2NH)20H2'CH20H2Si
(OCH3).

H3O-NHOONHO, H6O1(OCH,).

Further, the alkoxy group of the above compound may be a chlorine atom. These silane coupling agents are one or more /'i2
It may be used in a mixed system of more than one species.

■ The above charge-controlling mold release agents can be used alone, but they can be used in addition to conventional mold release agents such as dimethyl silicone oil, methyl fluorine silicone oil, and fluorosilicone oil. 1. It is also possible to apply a mold release agent containing a self-charge controlling mold release agent. In this case, in addition to being able to arbitrarily select properties such as thermal stability and viscosity, it is also possible to reduce the cost by relatively reducing the amount of relatively expensive amino-modified oil used.

You can also do it. For example, 5F841.7 (1550 per amino
0/Amino(thi) 0.5, Torre Silicone KK.

viscosity at 10. Viscosity in dimethyl silicone oil KF96H25ζ of OD Ocs 10,
000 cs (manufactured by Shin-Etsu Chemical KK) and 10-3wt
It was confirmed that even a sample with % added could be applied to the present invention as a charge control mold release agent. Of course, the amount to be added is not limited to the above-mentioned value, and by appropriate combination, even smaller amounts can be used as a charge-controllable mold release agent.

(2) Furthermore, a charge control agent having the structural formula shown below may be added to a mold release agent such as dimethyl silicone oil.

o NOL-3 (OLOA 31!+) R is polypdenoid o 0LOA 5080 0 Nylon 12 0 Duomine (Lion Armor Co.) R is an alkyl group 0 Armanc C HH ■, fatty acid monoethanolamide R-CO-NH-OH2CH20H For example R is C, , C, lauric acid, etc. ■, fatty acid jetanolamide 0H20H20H For example, R is C, , C, 2 acrylic acid, etc. The amount of the charge control agent added is based on the mold release agent. Even a small amount has a sufficient offset prevention effect. For example, silicone oil 1
A sufficient effect can be obtained even when the amount is about 10 −5 parts by weight relative to 00 parts by weight.

Group 2 of Examples of Charge-Controlling Mold Release Agents The following are charge-controlling release agents that rank more negatively than recording materials in the triboelectrification series.

(2) Silicone oils having halogen element groups, such as halosaponide-modified silicone oils, are suitable, and among them, those having chlorine atoms are preferred. In this example as well, the modification is not limited to silicone oil, but includes dimethyl silicone oil, fluorosilicone oil, methylphenyl silico-2, and silicone oils to which a fluorine-containing surfactant is added.

(2) Furthermore, fluorosilicone oil is effective as a negative charging agent, and it may be added to silicone oil.

I-hi's cargo J3. An example in which the mii decorative release agent was used will be described below.

EXAMPLES First, an example of a four-child photographic apparatus to which the present invention is applied will be explained with reference to FIG. 6, and then Examples 5 to 8 will be explained.

The photosensitive material for forming a latent image and the forming process shown in FIG. 6 are based on those described in Japanese Patent Publication No. 42-25910, but are not limited thereto. No. 2040, No. 42-19748, No. 43-24748, No. 45-37957
No. 49-27048, No. 44-1343
Publication No. 7, Publication No. 45-24077, Publication No. 43-179
No. 47, No. 45-25256, and other well-known methods can be applied. A description of the illustrated device will be added.

The photosensitive drum 2°, which has a photosensitive layer provided on a metal cylinder, is uniformly positively charged by a negative charger 21, and then re-charged by a secondary charger 22 which provides a charge with a polarity opposite to that of the primary charger 21. At the same time, the lamp 25 illuminates the original image, and this light image is applied to the photosensitive layer via the optical system 13.

As a result, an electrostatic latent image is formed on the surface insulating layer of the photosensitive drum 20 due to the difference in surface charge density according to the light and dark pattern of the light image, and then the entire surface of the photosensitive layer is uniformly covered with the full surface exposure lamp 14. By exposing to light, a difference is created in the surface potential depending on the brightness and darkness of the original image, and an electrostatic latent image with high contrast is formed.
Due to frictional charging with the toner, the latent image is developed and visualized by the negatively charged toner. The development process is described in Japanese Patent Application Laid-Open Nos. 55-18656 and 18657-1987.
No., JP-A-55-18678, JP-A-55-1867
The developing method and the rolling device described in each No. 9 were used.

Next, the toner image is positively charged by the transfer charger 18 to the back side of the support material 17 such as paper supplied from the cassette 24, and the visible image on the photosensitive drum is transferred onto the support material by the electrostatic attraction force. Transfer the toner image to rollers 1 and 2.
It makes your feet feel warmer.

The drum 20 is cleaned by the blade cleaning means 19 and reused.

[Example 5] Fig. 7 shows a structure similar to that shown in Fig. 4 above, but the scratches on the pressure roller containing the charging agent as described above are not present. The pressure roller 22' is pressed against the fixing roller 1 by a known pressure means at least during fixing, and has a relatively thick layer of elastic material such as silicone rubber, fluorosilicone rubber, or fluorosilicone rubber on the outer peripheral surface of a metal roller core. It is.

In this example, a positive charge control mold release agent is applied from the fixing roller 1F1 side in the same way as a normal mold release agent application means. 2
2, a positive charge control mold release agent is transferred via the circumferential surface of the heating roller. As a result, the frictional charging polarity of the pressure roller 2, which has a relatively small capacitance and is easily charged to a high potential, with respect to the copy paper is reversed, and the pressure roller 22 is charged to a positive high potential. Therefore, it is possible to minimize electrostatic offset to the heating roller and to obtain high-quality copies without image disturbances such as shading.

Specifically, the application member 161 applies the charge-controllable mold release agent from the side of the rotating body that contacts the toner image T, and
This causes a positive charge to be generated on the side of the rotating body that does not come into contact with the rotating body. This coating member 161 is a charge controllable release agent coating member that also serves as a cleaning member for removing foreign matter such as offset toner and paper dust attached to the surface of the fixing roller from the roller surface. Furthermore, apply N material 1 + h u Nomex,
Web 61 made of heat-resistant nonwoven fabric such as Himeron, Teflon, etc.
is impregnated with the above-mentioned charge-controlling mold release agent (for example, amino-modified silicone oil).

The coating member 161 has a structure in which the web 61 is made of silicone rubber,
A pressing row 265 having elasticity such as fluoro rubber, fluorosilicone rubber, or silicone rubber sponge is brought into contact with the heating roller.

The web 61 also has a winding roller 65 which is driven.
As a result, the cleaning web 61 is moved from the supply row 262 little by little to change its contact position, so that a new surface of the cleaning web 61 is always brought into contact with the heating roller. A guide plate 7 is inclined upward so as to guide the copy paper P carrying a toner image toward the heating row 21 side.

By the way, as mentioned above, the present inventors have confirmed that the offset of toner due to electrostatic force is largely dependent on the surface potential of the lawn, recording material, etc. Generally, the surface potential of row 2 can be expressed as V=(Jog(R/r)/2πε0εrl)·Q when it is considered as a coaxial cylinder. -・-tl) (where R: roller outer diameter (m), r
: Inner diameter of insulating surface coating layer (m) + go: 8.85
4X1 o-12"/m + gr: relative dielectric constant, l: length of insulating coating) Above formula (1) The larger the width (R-r), the smaller the relative permittivity. It can be seen that the roller is at a high potential.

In the configuration of this embodiment, the insulating coating layer 1 of the fixing row 21 is
1 is relatively thin, and the insulation ff1t22 of the pressure roller 2 is relatively thick, making it possible to minimize the frictional offset of the pressure roller. Additionally, it is possible to prevent image disturbances such as blurring that occurs mainly during fixing. Therefore, it is possible to obtain high-quality copies.

A roller with an outer diameter of 60mm with a 30 μi thick PFA M coating on an aluminum core metal, and a roller with a heat-vulcanized silicone rubber coating with a thickness of 5 mm on a stainless steel hollow core metal as a pressure roller. 26 sheets/min of plain paper (A3 size) (roller circumferential speed 2
The fixing process was performed at a speed of 70/see).

Further, as the charge control mold release agent impregnated into the web 61,
25? To 100 parts by weight of dimethyl silicone oil (Shin-Etsu Chemical Exhibition KF-96H) with a viscosity of 10,000 C days at A charge control mold release agent containing 0.1 part by weight of KF857 (manufactured by Kagaku Co., Ltd.) was added to a 15 m web of 90. li! The impregnated one was used.

Further, the web feeding speed was o, stttm 1 minute.

When 300 or more toner images were formed on A3 plain paper per sheet under the above conditions (conditions where offset is most likely to occur), the toner offset rate was 0.03%, and no problems occurred at all. . The toner offset rate mentioned here is defined by the equation ('2) below (toner offset rate) = ... (2) Also, the surface potential of the pressure roller after passing 99 sheets is +600
The surface potential of the heating roller was -100V, and the surface potential of the paper was +180V.

The above results are considered to result in a decrease in offset due to the following factors. That is, when a positively charged positive latent image is transferred onto plain paper after being developed with negative toner, the plain paper is given a positive charge and is transferred by electrostatic attraction with the negative toner.

That is, at this point, the plain paper is positively charged. After this, in the fixing process, when the plain paper P passes through the nip, it is frictionally peeled off and charged between it and the pressure roller 2, and at this time, the amino-modified silicone oil mixed with silicone oil, which is a charge control release agent, acts. The pressure roller becomes highly charged. In other words, the plain paper P is charged positively and negatively, which is opposite to the m charge, which should hold the negatively charged toner. As mentioned above, the inventors of the present invention elucidated this phenomenon by considering that the offset is related not to the amount of charge but to the potential. In other words, when the same amount of charge is transferred, the pressure roller, which has a smaller capacitance than the paper, has a much higher potential on its surface than the paper, and the charge on the back side of the paper increases. It does not exert a large static attraction on the negative toner on plain paper, so much so that it can be ignored.

In other words, during fixing, the negative toner is strongly held on the paper surface, so offset can be prevented.

Furthermore, it is thought that due to the above action, the amine-modified oil of the charge-controlling release agent that was applied to the scattered image during fixing is selectively transferred to the pressure roller at the nip. It will be done.

Next, continue copying under the above conditions and get 100.0
Even after passing 00 sheets, there was no change at all from the initial state, with very little offset, and high quality copies were obtained.

In addition, the heat resistance of amino-modified oil alone is about 140, but in this example, it is used in combination with silicone oil, so the silicone oil covers the amino-modified oil and has a heat-insulating effect, so it is 200C. Even when used at temperatures close to , the amine group does not decompose at all, and the effect can be maintained for a long time. In addition, 1 part by weight of amine-modified silicone oil was added to 100 parts by weight of dimethyl silicone oil.
By applying a charge control mold release agent mixed with 0 to 5 parts by weight to the lawn, the pressure roller potential became +6000 V or more, which was effective.

<Comparative Example 5> Next, as a comparative example, as conventionally done, the web 61 had a viscosity of 10,000 c at 25'C.
90g of B dimethyl silicone oil (Shin-Etsu Chemical Exhibition KF96H) in a 15m sea urchin
When the impregnated roller was used for paper passing and fixing in the same manner as in the example, the toner offset rate was 0.6%, and 5020 times as much toner was offset to the fixing roller as in the present example. In addition, image blurring occurred, and this increased as the sheets were continuously fed. This is due to the fact that the surface pattern of the pressure row 2 becomes larger as the sheets are continuously fed. In addition, the surface potential of the pressure roller after passing 99 sheets is more than -6ooov (approximately -4000V for one sheet passing), the surface potential of the heating roller 2 is -200V, and the surface potential of the paper is +21V.
It was 0v.

The reason for the above is that due to frictional peeling and stripping from the paper, the surface of the pressure roller has a very large negative potential compared to the paper, and the negative toner on the plain paper has a very large negative potential, so that the charge on the back side of the paper can be ignored. Due to the negative toner being transferred to the fixing roller, image disturbances such as offset and blurring occur due to the negative toner being transferred to the fixing roller.

[Embodiment 6] FIG. 8 shows another embodiment (similar to FIG. 7). Components that are the same as those in FIG. 7 are numbered the same, and their explanation will be omitted.

In FIG. 8, a porous film 25 of tetrafluoroethylene and a porous tube 26 are used as charge-controllable release agent coating members. 25 porous films, pore size 0.5-0.5
The porous tube 26 used had a hole diameter of 1.0 to 1.1 μm and an opening ratio of 85%.

A portion of the porous film 25 is thermally welded to a container 28, and the container 28 contains a charge-controllable mold release agent.

As the charge control mold release agent 27, an amino-modified silicone oil having a viscosity of 5,500 as at 25 mm and an amine equivalent of 2.000 was used, and paper was passed in the same manner as in the previous example. oo, oo.

Even after copying a sheet, the toner offset rate was 0.03 inches, and there was no image disturbance such as blur caused by electrostatic force, and high-quality copies were obtained.

In the above case, although the roller surface temperature was 180 υ while the paper was being passed, the temperature of the charge-controlling mold release agent in the container 21 was about 100 C, and there was almost no decomposition of the amino group, and good results were obtained over a long period of time.

To summarize Examples 5 and 6 above, the above example has a means for applying a charge controllable mold release agent to the first rotating body on the side that contacts the fixing object, and The method is characterized in that the charge controllable release agent is applied to a second rotary body which is in pressure contact with the first rotary body and is used to nip and convey the recording material. Further, the charge control mold release agent is charged to a polarity opposite to that of the object to be fixed, and is used to convert the second rotary member to the opposite polarity or to maintain the second rotating body at the opposite polarity.

Charge retention here means that even if the second rotating body is made highly effective in preventing offset using a charging agent as described above, the offset prevention effect is further improved and sustained by applying a charge control release agent. It means that it is possible.

In addition, in the above example, a positively chargeable release agent was used as the charge control release agent, but when the object to be fixed, such as a toner image, is positively charged, using a negatively chargeable release agent will achieve the above effect. is obtained.

Each of the embodiments described above is particularly effective when the first rotating body is relatively inactive and/or has a small frictional coefficient, and the second rotating body is relatively active and/or has a large frictional coefficient.

[Example 7] The example shown in this page is based on FIGS. 9 to 11, and its characteristics are as follows: , a second rotating body having an elastic layer that rotates in pressure contact with the first rotating body;
A fixing device having a rotating body and fixing an object to be fixed onto a recording material, characterized in that a charge controllable release agent is directly applied to the surface of the second rotating body, or (1) an object to be fixed. and (2) the coating member that applies the coating to the second rotating body.

In this Example 7, the charge control mold release agent is directly applied to the second rotating body, so the second rotating body can be set to the desired charging polarity, and its surface potential can prevent offset and scattering of the fixing object. Prevention and prevention of the transfer of the fixing object from the second rotating body to the back surface of the recording material can be easily achieved.

The fixing device shown in FIGS. 9 to 11 is applied to an electrophotographic apparatus as shown in FIG. First, the common configuration of each of these figures will be explained.

This figure shows a negative toner image T formed by an electrophotographic method using a heat fixing device with a thickness of several tens of microns (usually Fi 70 microns to 10 microns thick).
0μ) is fixed on plain paper P.

A fixing roller 1 has a heater 3 such as a halogen heater inside, and rotates in the direction of the arrow in response to driving force from a drive motor (not shown). 2 is a pressure roller, which is in pressure contact with the heating roller 1 and does not rotate by sliding.

This fixing roller 1 has a heat-resistant releasable resin layer 11 such as tetrafluoroethylene resin provided on the outer peripheral surface of a hollow roller core 12 made of metal such as aluminum, stainless steel, or steel to a thickness of 20 to 100 μm.

The pressure row 22 is rotatably supported by a bearing (not shown). The pressure roller 2 is pressed against the fixing roller 1 by a known pressure means (not shown) at least during fixing, and is coated with an insulating elastic material such as silicone rubber, furan rubber, fluorosilicone rubber, etc. The layer 22 is relatively thick (about 1 inch or more).The purpose of this structure is to secure the pressure contact area d with the heating roller. , a temperature sensing element 4 such as a thermocouple is disposed in contact with it, and its detection signal is guided to a known control means (not shown), and the fixing roller 21
The temperature of the outer peripheral surface of the heater 6 is maintained at the one-image melting temperature of the five toners by controlling the output of the heater 6 or the voltage applied thereto.

Reference numeral 16 denotes a cleaning member for removing foreign matter such as offset toner and paper powder adhering to the surface of the fixing roller from the roller surface, and is a cleaning web made of a heat-resistant nonwoven fabric such as Nomex or Himeron impregnated with silicone oil for offset prevention. 61. The cleaning web 61 is brought into contact with the fixing roller by an elastic pressing roller 63. Further, this web 61 is moved to a supply roller 262 by a winding roller 64 (not shown) which is driven.
The cleaning web 61 is moved so as to change its contact position little by little, so that a new surface of the cleaning web 61 always contacts the entire length of the surface of the fixing row 21.

55, 5□ is a roller for reliably separating the plain paper P as a recording material after fixing from the surface of each row 2, and the total pressure is 6
It is pressure welded with 0 pieces.

In the structure described above, the fixing roller 21 that contacts the toner image has an inactive resin layer on its surface with a small number of friction threads, while the pressure roller 22 has an active, relatively thick elastic layer with a large friction coefficient. have. Therefore, according to the above-mentioned equation (1), the surface potential of the pressure row 22 is the main cause of the offset occurrence.

In this embodiment, a charge-controlling mold release agent is directly applied to the elastic surface layer of the pressure row 22 in order to vary or improve the charge polarity of the pressure row 22 or to maintain the charge and prevent offset and image scattering. do. Hereinafter, specific numerical examples will be explained using the drawings.

In FIGS. 9 to 11, the fixing process was performed at a speed (roller circumferential speed of 27011 LN/sec) capable of processing 23 sheets of Japanese Industrial Standard A3 size paper per minute as plain paper P. Furthermore, using negatively charged toner (negative toner) and forming a toner image of 500m9 per sheet of A6 plain paper, under conditions where offset is most likely to occur during the fixing process (dark thin line images, etc.), A3 paper A toner image was formed on the paper.

First, using the fixing device described above, uniformly apply a charge-controlling mold release agent mainly composed of the above-mentioned amino-modified silicone oil, trade name 5F8417, on the surface of the pressure row front 2, The above conditions were established. As a result, the toner offset rate according to the above formula (2) is 0.0
3, the surface potential on the pressure roller was +6000 or more.

On the other hand, when only conventional methyl silicone oil was applied without using a charge control mold release agent (8F8417), the pressure roller showed a surface potential of 16,000 V to minus tens of thousands of volts, and the toner offset rate was also extremely large at 0.6.

This phenomenon will be explained. Plain paper P up to the fixing device
(positive) has sufficient potential to attract the toner image (negative). However, in the conventional case, the pressure roller and the plain paper cause frictional separation electrification, and the pressure roller is strongly negatively charged and the plain paper is positively charged. Therefore, plain paper PVC has an increased potential to attract toner to some extent. However, the pressure roller creates an electric field that is much larger than the electric field generated by the plain paper P and causes the toner to scatter toward the heating roller.

Therefore, the conventional method has many offsets and the image is distorted.

In contrast, in the embodiment of the present invention, a large positive surface potential is formed on the pressure roller mounting surface, so that the offset can be minimized.

Note that when the pressure roller 2 is positively charged, it gives a negative charge to the plain paper P that causes the toner to scatter, but the surface potential is not very large and is compared to the positive surface potential created by the pressure roller 2. It's just something that can be ignored.

In this embodiment, since the negative toner is strongly held on the paper surface during fixing, offset can be prevented, and toner scattering on the fixing roller 1 can also be prevented, resulting in improved image quality.

The effect of this example was sustained even after 3000 sheets were continuously subjected to the fixing process, even though the coating was performed only once before fixing.

In this example, the coating is applied before fixing, but when viewed as a single roller, it was applied to the surface of Row 2 by packaging the roller with a packaging member coated with a charge control release agent on the surface. Anything is fine.

That is, the pressure roller provided with the charge controllable mold release agent exhibits an excellent offset prevention effect.

The above embodiment is effective for models that use a relatively small number of sheets or models that do not perform continuous copying often because the offset prevention effect can be maintained over a long period of time.

In the embodiment shown in FIGS. 9 and 10, unlike the above example, the charge control mold release agent is continuously applied to the pressure row 22, and FIG. The coating is applied intermittently.

These can maintain the effects of the above-mentioned embodiments semi-permanently for a longer period of time.

As shown in FIG. 9, in a fixing device having a configuration similar to that of the embodiment described above, a heat-resistant nonwoven fabric 61 having a width of 10 mm and a thickness of 2 mm is supported by a support member 60 and is in contact with the pressure roller 2 over the entire length thereof. It is set up in The heat-resistant nonwoven fabric 31 is impregnated with 10 CC of a charge-controlling mold release agent obtained by adding amino-modified silicone oil KF857 to methyl silicone oil KF96H at a weight ratio of 0.01 wt%. With the configuration of this example, when a toner image was fixed on plain paper under the same conditions as in the previous example, intermittent copying of 1 sheet per minute resulted in so, o
The offset rate is 0.03% or more even after making 0 copies.
The potential of the F-pressure roller was +6000V or more, and the effect continued.

The amine-modified silicone oil may be applied via an application roller, or may be applied to the rotating body at predetermined rotational speeds using an eccentric cam for approaching and separating.

In FIG. 10, a positively chargeable charge control mold release agent 63 is contained in a container 64 having a coating amount regulating blade 341, and the mold release agent 53 is supplied from this container 64 by an application roller 62. An example is shown below. This application roller 62 rotates in the same direction as the pressure roller 2, and the charge control mold release agent 35
It has a length that allows it to be applied to the entire pressure roller 2.

The rotation control of the coating row 232 may be continuous or intermittent.

The application member of this example is made of a material having the components of plain paper P.
By using a material that is negatively chargeable with respect to the charge control release agent (positive charge '1 property), the second surface of the pressure roller can be positively and uniformly tribo-electrified before fixing the toner image T on the plain paper P. I can do it.

This technical concept is effectively applied to both positive and negative toners in accordance with the basic outline of the present invention. This makes it possible to compensate for the lack of triboelectric charging at the rise.

Of course, the above explanation can also be applied to other application members.

As another embodiment 10, FIG. 11 shows one in which the charge control mold release agent of the present invention is applied to the pressure row 72 only during copying. Reference numeral 35 denotes a heat-resistant nonwoven fabric containing the charge-controlling mold release agent of the present invention, and is normally spaced slightly from the surface of the pressure row 2.

It is fixed to the board of the device at Noshiman.

1 starts rotating, pressure roller 2 rotates under pressure and expands,
The pressure roller comes into contact with a heat-resistant nonwoven fabric impregnated with a charge-controllable mold release agent, and the charge-controllable mold release agent is applied to the surface of the pressure roller. After copying is completed, the pressure roller 2 contracts again due to natural heat dissipation and separates from the heat-resistant nonwoven fabric. This can effectively prevent the charge-controlling mold release agent from being thermally degraded.

In this example, as a charge control mold release agent of the present invention, 0.1 wt % of amino-modified silicone oil KIj'595 was added to dimethyl silicone oil KF96, and an outer diameter of 60 mm and an elastic layer were prepared. Using 5 pressure rollers,
Roller circumferential speed 270 V for Japanese Industrial Standard A3 size plain paper
The fixing process was performed at a speed of rtn/sec. I used a toner with a negative band (negative toner) and fixed the toner at 300rn9 per sheet on A6 plain paper, making intermittent copying of 20 sheets in 10 minutes for a total of 70 sheets.
Even after fixing 000 sheets, a good offset prevention effect was confirmed with an offset rate of 0.03%, and there was no image disturbance.

As is clear from the above, a positive charge-controlling mold release agent (it is more preferable to have a property with a high degree of stability) is applied to the recording surface on the side opposite to the side where the unfixed negative to-be-fixed material is fixed. By applying it to the rotating body that comes into contact with the material surface, it is possible to achieve better offset prevention than ever before, and it is also possible to better prevent image disturbances such as blurring. On the other hand, if the unfixed object to be fixed has a positive charge in the configuration of the above embodiment, a charge controllable mold release agent with negative chargeability may be used.

The durability can be further improved.

Of course, this embodiment 7 can be applied to any rotating body that comes into contact with a recording material and causes a frictional factor that offsets the fixing object (for example, one having an insulating layer thicker than the thickness of the recording material), and can be applied to any pressure fixing device. Needless to say, it can also be applied to

[Example 8] Example 8 shown in the following is a structure characterized in that a charge control mold release agent is contained on the surface of the rotating body, thereby preventing offset and image scattering 9.

To briefly summarize the example, the first product whose surface layer is coated with mold releasability.
The fixing object has a rotating body and a second rotating body whose surface layer is coated with an elastic material and is in pressure contact with the first rotating body, and by sandwiching and conveying the recording material between the first and second rotating bodies, In the fixing device for fixing to the recording material, the second rotating body is a fixing device characterized in that it has a surface layer impregnated with a charge-controlling and amphoteric release agent.

This will be explained using FIG. 12. Although FIG. 12 is similar in structure to FIG. 4, the pressure roller 2' is different. The following will mainly explain the differences.

The fixing row 21 has a heat source 3 therein, and has a heat-resistant release resin layer 11 made of tetrafluoroethylene resin FTFB or PF'E on its surface with a thickness of 20 to 80 μm. The pressure roller 2 is in pressure contact with the fixing point o-2 and is made of silicone rubber or fluorine rubber, 70
The elastic material layer 22 made of silicone rubber or the like is relatively thick in the range of about 1 to 5 mttt. The other configurations are the same as in FIG. 4.

The charge control mold release agent that can be applied to this Example 8 includes those in the groups 1 and 2 mentioned above, but especially those that do not significantly impair the characteristics and physical properties of the material when impregnated or added to the rotating body. things are suitable.

Also, in addition to the above, for example? A charge control mold release agent prepared by adding 1% by weight of 395 (amine equivalent: 3601, manufactured by Shin-Etsu Chemical Co., Ltd.) to a dimethyl silicone oil (such as KF96) having a viscosity of 100 as at 25'T: is also suitable.

When a charging agent having charge control properties is mixed into the broiler agent as described above, it is preferable to add a larger amount of the charging agent than in the case of coating. However, the insulating coating layer is relatively thin compared to the weight ratio, and the insulating layer of the pressure roller is relatively thick. This makes it possible to minimize the image quality, and in conjunction with this, it also makes it possible to produce high-quality copies that prevent image disturbances such as blurring that occurs mainly during fixing.

In this example, by impregnating or adding a positive charge control mold release agent into the pressure roller in advance, the pressure roller 2, which has a relatively small capacitance and is easily charged at a high potential, can be used with copy paper. It has become possible to minimize the frictional charge electrode offset and to obtain high-quality copies without image disturbances such as blurring.

The following F will be shown using specific numerical examples. A pressure roller applicable to this example was manufactured using the following manufacturing method.

60 parts by weight of a reinforcing filler such as fine silica powder is mixed with unvulcanized silicone rubber per 100 parts by weight of unvulcanized rubber, and the mixture is thoroughly kneaded with a vulcanizing agent to form an unvulcanized garbage sheet. And so. The above-mentioned unvulcanized rubber sheet was prepared after being left at room temperature for 6 days.

Next, a stainless steel core metal having an outer diameter of 50 mm was subjected to a blast treatment, and then an adhesive was applied thereto and left in a 25'C environment for 5 hours, followed by baking at 120C for 20 minutes. The core metal is covered with the unvulcanized rubber sheet, and the pressure is 150.
9/α2 and a temperature of 170C for 30 minutes - post-vulcanization tV was obtained (using a press vulcanizer). Further, after secondary vulcanization was performed for 4 hours with 20021', it was ground to an outer diameter of 59.8 ml.

Next, the roll was coated with dimethyl silicone oil (Shin-Etsu Chemical Exhibition, KF96:25?l: viscosity: 100
cs) to 100 parts by weight of amine-modified silicone oil (Shin-Etsu Chemical Exhibition KF857: Structural formula A type,
Viscosity at amine equivalent of 830.25 t' is 70 cs
(1 part by weight) was immersed in a charge-controlling mold release agent mixed with the mold, keeping the liquid temperature at 70r, left to swell for 48 hours, and then finished polished to an outer diameter of 60mm and used as a pressure roller. did.

The roller is positioned more positively in the triboelectrification series than copy paper, which is a recording material.

As the fixing roller 1, a 30 mm
A roller with an outer diameter of 60 μm coated with PFA and a pressure roller 22 is used, and the total pressure of both rollers is 60 μm.
23 sheets/min of plain paper (A3 size)
The fixing process was performed at a roller circumferential speed of 270 ym/θec. In addition, as a dispersing agent to be impregnated into Kuep 61, dimethyl silicone oil (Shin-Etsu Chemical Exhibition, NIP-96H) having a viscosity of 10,000 CB at 25'c was added to a 15 m web of 90. The one impregnated with li+ was used.

Further, the web feeding speed was 0.5 mm/min.

When we fixed a toner image of 300 dah per sheet on A3 plain paper under the above conditions (Canon test chart; conditions where offset is most likely to occur), the toner offset rate was 0.03 dah, which was no problem at all. No voltage was generated and the voltage was 250V, and the surface potential of the paper was +180V.

The above results are considered to result in a decrease in offset due to the following factors. The amino-modified silicone oil mixed with silicone oil, which is a charge control mold release agent impregnated into the pressure row 2, acts to make the pressure row 2 highly positive.

In other words, the plain paper P is negatively charged, which is opposite to the positive charge that should hold the negatively charged toner.

When the tab 9 is fixed, the negative toner is strongly held on the paper surface, so offset can be prevented. Moreover, due to the above-mentioned effect, there was no image scattering or disturbance during fixing, and high-quality copies were obtained.

Next, continue copying under the above conditions and make 100.00
Even after passing 0 sheets, the offset is very small.
And a high quality copy was obtained. In addition, the heat resistance temperature of the amino-modified silicone oil alone is about 140 t:, but in this example, the surface temperature of the pressure row 2 was 110 to 100 t at the time of copying.
120, and because the amino-modified silicone oil is mixed with the silicone oil, the heat resistance of the amino-modified 7-recon oil is higher than that of a single substance, so the thermal decomposition of the amino group is extremely difficult. It is small and the effect can last for a long time. Furthermore, in order to stabilize the image forming apparatus, it is a preferable embodiment to separate the pressure roller from the fixing roller 2 during standby and rotate the pressure roller only during copying.

The effect of this example was also equivalent to that of Example 7 described above. In the above example, the desired pressure roller was manufactured by swelling the pressure roller after vulcanization with a positive charge control mold release agent, but in this example, the pressure roller was It is important that the rubber contains a positive charge control mold release agent. For example, when unvulcanized rubber is mixed, even if it is vulcanized after adding amino-modified silicone oil, it will not work as in this example. Almost the same effect can be obtained.

As described above, the present invention focuses on electrostatic force, which is one of the major causes of toner offset to the fixing roller, and by adding a charge controllable release agent to the pressure roller,
It has become possible to obtain a fixing device that has good mold releasability over a long period of time, has little offset, and can produce high-quality copies. Furthermore, although this embodiment has been described only in the case where negative toner is used, the technical concept of this embodiment can also be applied to the case where positive toner is used. This example is also applicable not only to heat roller fixing, but also to pressure fixing devices.0 <Photo explanation> Here, the effects of the present invention are visually shown0 Figures 13 to 29 is a photograph showing the results of an experiment conducted under the following experimental conditions.〇-Experiment Condition 11 Machine used: (Product name) NP-4QQRE Copy speed A626 sheets/min Roller circumferential speed 270 mm/sec Z fuser configuration : Fixing roller (outer diameter 60 mm) on aluminum core [30 μm thick PFA coated pressure roller (outer diameter 60 mm)
) 5mm thick heat-vulcanized silicone rubber coating on iron core ball (rubber hardness: JISA 40 degrees) Nip width: 8.5mm Fixing roller surface temperature: 186°C ± 0.5°C Fixing hill'
-: ' 870W Norogen heater pressure heater:
90W sheathed heater 3, latent image formation 2 Method N
P prosenu (PC layer CaS) conditions Vo=+450V
VL=OV (automatic control) 4, development 87 method Jumping development conditions Gap between S (sleeve) and D (drum) 600μs
Gap between and B (blade) 240μ 5, Toner = (Product name) Toner 6 for NP-400RE, Paper used: Canon Dry Pape
r' (Lot, No, A3-2HHO24) 7. Environment: 26°C, 60% (Canon constant temperature and humidity chamber) 8. Usage chart: NA-2 chart shown in Figure 60 A, B, and C (CANON TEST 5HE
ET-NA2) 9. Cleaning: Cleaning member 16 (web cleaning) shown in FIG. 4 Web feed speed 2.5 mm/min.

Web pressure contact width by the pressing roller 63 is 7 mm.The chart used above is for forming a large amount and fine unfixed toner image on the paper used.The above experimental conditions have a high rate of occurrence of offset, so the above-mentioned example This increases the web feed speed.

1.Results 1.Images 16 to 16 are shown in FIG. 60B respectively.
This is an enlarged microscope photograph taken at a magnification of 20 times after fixing a portion of 2 charts rl, 8J ", 8" on the paper used, and a close-up photograph of this. Of these, FIGS. 16 and 15 show that amino-modified silicone oil (an example of a positively chargeable charge control mold release agent) according to an embodiment of the present invention is applied only once to the circumferential surface of the pressure roller. In contrast, Figures 14 and 16 are conventional examples in which dimethyl silicone oil is applied to the circumferential surface of the pressure roller. These are the 1st and 99th enlarged photos taken when the stain was fixed after only a few times. Therefore, the effect of the present invention becomes clear by comparing FIGS. 15 and 14, and also by comparing FIGS. 15 and 16.

That is, in the conventional fixed image shown in FIG. 14, a large amount of toner is scattered around the image ",8", whereas in this embodiment shown in FIG. It has been reduced to These differences and this toner scattering are difficult to judge visually, but when magnified in this way, the difference in effectiveness becomes clear.In Figures 13 and 14, only one sheet is being passed, so the pressure roller Although the surface potential is not that large, as the fixing process progresses or continuous fixing is performed, the surface potential becomes even greater, producing a more distinct difference in effect. This is the 15th factor and Figure 16.

In the conventional fixed image shown in FIG. 16, the image scatters so much that the image is deformed to the extent that it can be visually determined. On the other hand, in this experimental example shown in FIG. 15, a clearer image could be obtained and the amount of toner scattering could be reduced compared to the first sheet of FIG. 13. This is because the charging agent and the charge-controlling release agent of the present invention provide the pressure roller with a surface potential sufficient to deflect the toner toward the paper used.

As shown above, in this experimental example, it was possible to prevent the fixed image from scattering and to obtain a clear image.

This effect is common to many of the embodiments of the present invention described above.

(2) Offset to the fixing roller surface Next, FIG. 17 (conventional) and FIG. 18 (this experimental example) will be compared. Figures 17 and 18 are Figures 14 and 1, respectively.
After fixing ", 8" in Figure 3, the fixing roller NThK mylar tape was pasted, the offset toner was transferred to the fixing roller surface, and this was taken as a microscope enlarged photograph at a magnification of 20 times, and a close-up photograph was taken. It is.

In the conventional example shown in FIG. 17, a much larger amount of toner adheres to the surface of the fixing roller than the above-mentioned image scattering. This is because the pressure roller has a surface potential sufficient to orient the toner image onto the surface of the fixing roller. In contrast, in this experimental example shown in FIG. 18, there is almost no toner offset on the surface of the fixing roller. In other words, in this experimental example, the surface of the pressure row 2 has a surface potential sufficient to prevent offset, so that such excellent effects can be achieved.

Note that although FIGS. 17 and 18 above show the offset state when #i is fixed on a single sheet, this tendency is the same in continuous copying. In addition, in the conventional example shown in FIG. 17, the amount of K offset toner increased as the number of consecutive copies increased, but in this experimental example, it was the same as in FIG. 18.

As is clear from the above, the offset prevention effect common to all of the present invention is extremely excellent as shown in FIG.

■ Offset amount for continuous copying Figures 19 to 22 show the amount of toner offset on the surface of the fixing roller in units of 100 continuous sheets, respectively, after cleaning with the dimethyl silicone oil-impregnated cleaning web shown in Figure 26. This photo was taken at approximately life size after the web was laminated. The 19th of these
The figure shows a conventional example in which the pressure roller itself is used and the first
The offset toner generated by continuous copying from the 10th sheet to the 100th sheet is shown. Also, Figures 2o and 21.

Figure 22 shows the results for the first to 100th sheet of paper after applying the amino/modified silicone oil once to the pressure roller in this experimental example.
The web after continuous copying of the 401st to 500th sheets.

The numbers after continuous copying from the 901st sheet to the 1000th sheet are respectively shown.

In the conventional type shown in FIG. 19, the amount of offset toner is large, and a mountain of toner is accumulated that the web cannot hold. This amount of accumulation is especially formed in the wavy portion on the right side of the photo. The amount of accumulation is difficult to see in photos, but the photos on the web are laminated, so you can tell. That is, although the laminate wraps the web so as to connect the tops of the mountains and the toner on the flat surface, air that appears white is interposed between the mountains and along the slopes of the mountains. This white-looking air (mainly along the longitudinal direction of the web)
The magnitude of the accumulated amount can be understood by this. Obviously the one in Figure 19 is offset.

There is a large amount of

On the other hand, in this experimental example shown in FIG. 20, there was no mountain-like accumulation as shown in the photograph shown in FIG. 19, and the overall amount of offset toner was 0 or 1. Even the white background of the web can be seen between the t7 set toners, and there is even a surplus of IJ-ning ability. The excellent anti-offset effect of this example is clearly demonstrated.

Furthermore, in this experimental example shown in FIGS. 21 and 22, the second
The number of onset toner lids is even smaller than in Figure 0. This indicates that the pressure roller forms a triboelectric surface potential sufficient to attach the toner image to the paper used, and the thickness of the surface potential gradually increases. In other words, this shows that the charging agent and the charge-controllable mold release agent applied to the pressure roller generate a charge that prevents offset due to friction, and exhibits an excellent offset prevention effect. Furthermore, the present invention shows that the more friction is used, the more the offset prevention effect can be improved.

In the case of the conventional example in which continuous copying is performed as shown in FIGS. 21 and 22, even more offset toner is used than the toner offset amount shown in FIG. 19. Therefore, only FIG. 19 is shown here for comparison.

As described above, since the present invention can significantly prevent onset, it is possible to reduce the burden on cleaning members such as the web, and to reduce the amount of cleaning members consumed.

(2) Comparison The load on Kokotechahou Ep will be compared between this experimental example (amino-modified silicone oil applied), the case where only the above-mentioned KaD pressure roller is used, and the case where the silicone oil of trade name KF9 (5I) is continuously applied.

Figures 24 to 26 are photographs of the amount of offset toner at the time of continuous copying of the 201st to 300th sheets. The figure shows the case of silicone oil (KF96H). Similarly, Figures 27 to 29 are photographs of the amount of toner (a)) at the time of continuous copying of the 100th sheet a to 100th sheet, in order of this experimental example, only the pressure roller, and silicone oil (KF 96 H).
In this experimental example shown in FIGS. 24 and 27, the cases of A/F sex shown in FIGS. 20 to 22 shown above are used. In order to reduce the content of amino-modified silicone oil compared to when applying J-con oil, it is mixed with silicone oil and applied.

Compare FIGS. 24 to 26. Figure 26 shows a fixing device configured to prevent offset using conventional silicone oil.Although there is a slight difference in the amount of offset toner compared to Figure 25, the amount of offset toner is quite large and accumulates like a mountain. You can even see it. On the other hand, the 24th
In this example shown in the figure, the amount of offset toner is smaller than in the previous example shown in FIGS. 20 to 22, and a considerable amount of cleaning ability is left. This is considered to be because the amide/modified silicone oil and the normal silicone oil took some form, and the surface potential due to triboelectric charging and the non-adhesive property of the silicone oil mutually prevented offset.

Therefore, using the amino/modified silicone oil not alone but dispersed in the mold release liquid produces more favorable effects.

Next, compare FIGS. 27 to 29. In Figures 28 and 29, the amount of offset toner is large as in Figures 25 and 26, but it is slightly smaller than in Figures 25 and 26. This is probably because there is a slight difference in the pressure roller surface potential due to the different copy numbers.

On the other hand, in this example shown in FIG. 27, the amount of offset toner is much smaller than in the case of FIG. 20. Therefore, in the initial state, ¥It
It is preferable to apply the mold release agent or the charge control mold release agent at a thin concentration of one concentration.Also, these effects and results are common to each of the examples in the text.

As is clear from the above, by applying a charging agent or a charge control mold release agent together with a mold release agent, a charging agent can be formed.

The consumption of the charge control mold release agent can be reduced and the offset prevention effect can be improved.

In addition, the experiments explained in each section of above ■ to ■ are shown in Figure 30A,
CANON TEST 5HEET-N shown in B and C
This is the case when A2 was used as a document, and the test was carried out under conditions where normal document twist offset is likely to occur. Therefore, the effects of the present invention are very large, and the fixing device or fixing device is highly practical. It is possible to provide a roller for cleaning, a charging agent (or charge controlling release agent) coating member for preventing offset, or a coating member that also serves as cleaning.

Figure 60 A, B, and C are Japanese Industrial Standard A6 size pieces having lengths in the longitudinal direction, cut in the order of A, B, and C and attached (to match the method). The connection is that the lower part of Figure 60A and the upper part of Figure 60B are connected, and the lower part of Figure 60B and the upper part of Figure 60G are connected, respectively. , 28 and 29, the offset (offset) toner accumulated in the shape of a mountain is caused by continuous copying of several tens of sheets. This accumulated toner does not pose much of a problem as long as the web is moving, but once the nib has stopped and the fixing roller rotates, it will be transferred to the surface of the fixing roller.Next, this toner will transfer to the pressure roller and the next This transfers to the back side of the used paper, causing stains on the back side of the used paper and creating awn marks.

However, in the present invention, such accumulation can be largely prevented, so such problems can be prevented and web consumption can be reduced.

<Supplementary Examples> In the above-mentioned Examples of the present invention, in order to prevent the offset phenomenon of the object to be fixed, a charging agent, a charge control release agent, or a release agent containing these dispersed in a release agent, etc. is applied. coating parts,
A fixing rotary member or a conveying rotary member to which these are added, mixed, immersed, or chemically bonded, or a fixing device having a fixing rotary member to which these are optionally applied will be described below.

Each of the above embodiments has excellent effects, but each has its own unique characteristics.

That is, in the above-mentioned application member (d), it can be easily applied to the image forming apparatus such as a copying machine in use, thereby greatly preventing the occurrence of image distortion or offset. It can be applied very easily to models that are coated with a release agent.In addition, it can be applied to the fixing rotor and conveyance rotor, which itself has charging characteristics suitable for preventing offset. Because of this, the offset prevention ability can be fully demonstrated.Furthermore, excellent offset prevention can be achieved by simply replacing the rotating body with existing models, making it practical and simple. With the device, offset can be easily prevented without using other complicated devices or having many problems, and the fixing state of the fixing object can be made clearer.

　　.

In the above embodiments, the case in which the charging agent or charge control release agent is contained on the surface of the rotating body and the case in which the agent is applied to the surface of the rotating body were explained separately, but combinations of these are also included in the present invention, and more A permanent offset prevention effect can be achieved. In addition, the configuration lines of the above embodiments may be arbitrarily combined to prevent offset. In the above embodiments, the rotating body containing a charging agent or a charge controllable mold release agent has a surface potential suitable for preventing offset. However, it is effective to supply a charging agent or a charge-controlling mold release agent by coating, as it can further improve durability. It is preferable to contain or apply the compound mixed with a liquid having mold releasability, and it is more preferable to use a compound chemically bonded to the liquid in order to further equalize its dispersibility. It is particularly effective to apply this method to a second rotating body in pressure contact with the first rotating body when the first rotating body in contact with the fixing object has a relatively inactive surface or a thin release layer. This is particularly effective when the rotating body has an active insulating layer, and when the insulating layer is thick. If applied as a fixing device or a fixing roller of an image forming apparatus having means for transfer development, it is extremely effective because image scattering can be largely prevented. It is effective that the transfer developing means has a gap with the latent image carrier and applies alternating current and/or direct current to transfer and adhere the toner.

As described above in detail, the present invention has excellent effects such as being able to significantly prevent the offset phenomenon of the to-be-fixed object and greatly reducing the scattering phenomenon of the to-be-fixed object.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram for explaining offset generation according to the present invention, FIGS. 2 to 5 are explanatory diagrams showing embodiments of the present invention, and FIG. 6 is an electrophotographic apparatus to which the present invention is applied. 7 to 12 are explanatory diagrams for explaining the details of the present invention, Figures 16 and 15 are enlarged photographs of the husband image, and Figure 17 is a conventional diagram. Figure 18 is an enlarged photograph of toner offset on the surface of the fixing roller when fixed according to an embodiment of the present invention. and web photos,
Figures 20 to 22 are photographs of the toner and web attached to the cleaning web during fixing according to an embodiment of the present invention, and Figure 26 is an overall view of the cleaning web used in the present invention from an oblique direction. The photographs, FIGS. 24 and 27, are photographs of the toner and web attached to the cleaning web during fixing according to an embodiment of the present invention, respectively.
FIG. 25 and FIG. 28 are photographs of the toner and web that adhered to the cleaning web during fixing using a conventional pressure roller, respectively, and FIG. Figure 29 is a photograph of the toner and web that adhered to the cleaning web when conventional silicone oil was applied to a conventional pressure roller and fixed, respectively, Figure 60A, Figure 60B
, and FIG. 60G are sample views of manuscripts used in an embodiment of the present invention. 1.8 is a fixing four-ra, 11 is a heat-resistant mold release resin layer, 2.9
22 is a pressure roller, 22 is an insulating elastic layer, 6°6' is a heater, 61 is a cleaning web, 7 is a heat-resistant nonwoven fabric, 9
1 is silicone rubber sponge, 92 is silicone rubber coated,
15 is a magnifying device, 16 is a cleaning member, T is a toner image, and P is plain paper. Applicant: Canon Co., Ltd. Procedural Amendment (Method) May 2b, 1988 Kazuo Wakasugi, Commissioner of the Japan Patent Office 1 Indication of the case 1981 Patent Application No. 1561 2 Name of the invention Fixing device and fixing roller 3 Amendment Relation to the matter Patent Applicant Place Tokyo 1.11 Ward Shimomaru F3-30-2 Name (+00) Canon Co., Ltd. Representative Ryu Kaku 3rd Department 4 Agent Residence (7) 146 Tokyo 3-30-2 Shimomaruko, Ota-ku
5. Date of amendment order: April 26, 1982 (shipping date) - Description and drawings subject to α amendment 7, contents of amendment (11F3A specification, page 100, line 4 to page 112, line 6)
[〈Photo explanation〉〉〉〈Photo description〉〉〉〉Consumption can be reduced. ” to be deleted. (2) Specification, page 115, line 14 to page 116, line 16
Delete the line [Figures 13 and 15 are sample figures of the manuscript]. (b) Delete the drawings from Figure 13 to Figure 30C.

Claims (1)

Scope of Claims: (1) A fixing device that fixes a fixing object having a predetermined polarity onto a recording material by sandwiching and conveying the recording material between the first and second rotary bodies, A fixing device characterized in that a frictional charging agent is applied to at least one of the rotating bodies to form an electric field that causes the object to be fixed to adhere to the recording material. (2) In a fixing device that fixes a fixing object having a predetermined polarity onto a recording material by sandwiching and conveying the recording material between the first and second rotary bodies, the first and second rotary bodies A second rotation in which a charge-controlling release agent is applied to at least one side of the recording material to form an electric field that causes the object to be fixed to adhere to the recording material. a fixing device which fixes the object to be fixed on the recording material by sandwiching and conveying the recording material between the first and second rotating bodies, the second rotating body and the object to be fixed; A fixing device characterized in that a charging agent or a charge-controlling release agent is applied to a surface portion of the second rotary member so that the polarities of the fixing device are different from each other. a second rotating body, the fixing device fixes the object to be fixed on the recording material by sandwiching and conveying the recording material between the first and second rotating bodies; A fixing device characterized in that a charging agent or a charge controllable release agent is applied to a surface portion of the first rotating body so that the polarity thereof is the same as that of an object to be fixed. (5) A fixing roller whose surface portion is added to, immersed in, contains, or mixed with a charging agent or a charge-controlling release agent. (6) The fixing roller is used on the side that does not come into contact with an unfixed object, and the charging agent or charge control release agent has a polarity opposite to that of the unfixed object. Claim 5, characterized in that the charging agent or the charge-controlling release agent has the same polarity as the object to be fixed. 6. The fixing roller according to claim 5, wherein the fixing roller is polarized. (8) An application member that holds a charging agent for applying the charging agent to the fixing rotating body. (9) A coating member containing a charge-controllable mold release agent for applying the charge-controllable mold release agent to a fixing rotating body. (10) The coating member according to claim 8 or 9, wherein the coating member contains a mold release liquid. (11) Claims 8 to 10, characterized in that the application member is in the form of a web or felt.
The application member according to any one of paragraphs.