JPH0652457B2 - Toner image fixing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention permanently fixes an unfixed toner image formed on the surface of an image supporting material such as a transfer material, electrofax paper, or electrostatic recording paper by electrophotography, electrostatic recording, or any other suitable image forming method. A device for fixing a fixed image on the surface of an image supporting material, more specifically, for introducing and passing an unfixed toner image supporting material between a pair of parallel rollers composed of a fixing roller and a pressure roller which are rotated by being pressed against each other. The present invention relates to a roller type toner image fixing device for fixing a toner image on the surface of an image support material by heat, heat, pressure or pressure.

Since the heat fixing method is mainly used as the roller fixing method, this example will be described below. FIG. 1 is a cross-sectional side view showing a very schematic structure of a heat roller type toner image fixing device. In the figure, reference numerals 1 and 2 denote a heat roller (hereinafter referred to as a fixing roller) and a pressure roller, which are in proper pressure contact with each other and supported by bearings in parallel vertically, and are driven to rotate in the direction of the arrow.

The fixing roller 1 is a hollow roller 11 made of metal such as aluminum.
A core metal, and the outer periphery of the core metal is covered with a heat-resistant / wear-resistant release material layer 12 that does not easily cause toner offset, and a heater 13 such as a halogen heater rod is inserted in the inner space of the core metal. Is heated by the heat generated by the heater. Then, the energization of the heater 13 is controlled to be turned on / off or the amount of energization is controlled to be increased / decreased by an unillustrated automatic temperature control means so that the temperature of the outer peripheral surface of the fixing roller is constantly maintained at a predetermined substantially constant temperature (for example, 180 to 200 ° C.) To be done.

The pressure roller 2 is made of a metal roller such as iron or aluminum and has a cored bar 21 with an elastic material layer 2 such as rubber having a relatively thick outer periphery.
It is coated with 2.

3 is a device for applying silicone oil as a release aid to the outer peripheral surface of the fixing roller 1. A long web member 31 preliminarily impregnated with silicone oil is wound into a roll and mounted and held on a payout shaft 32. Then, the free end of the roll-wound web member is locked to the take-up shaft 33, the web member portion between the pay-out shaft and the take-up shaft is pressed against the fixing roller 1 surface by the pressing roller 34, and at the same time, the pay-out shaft side. The roll-rolling web member of 1 is wound little by little on the winding shaft side (for example, 1 m / 10,000 sheets (A4 size) is passed) to fix the fixing roller 1.
The outer peripheral surface of is coated with the impregnating release agent of the web member. This web member also serves as a cleaning member for the outer surface of the fixing roller.

When the fixing roller 1 and the pressure roller 2 are rotationally driven, the unfixed toner image T is formed on the nip portion 4 of both rollers.
When the image supporting material 5 carrying the toner is introduced and passed with the toner image bearing surface side being the fixing roller 1 side, the toner image T is heated by the fixing roller 1 and the mutual pressing force of the fixing roller 1 and the pressure roller 2. The heat and pressure fixing process is sequentially performed on the surface of the image supporting material 5 as a permanently fixed image.

Incidentally, 6 is a separating claw member arranged to surely separate the image supporting material 5 from the surface of the fixing roller 1, 7 is a sensor for detecting the outer temperature of the fixing roller 1 for controlling the temperature of the fixing roller 1, and W is the fixing roller. 1 shows a width dimension (nip width) of a mutual contact portion (nip portion) between the pressure roller 1 and the pressure roller 2.

In the fixing roller 1, the layer thickness of the releasable material 12 covering the outer circumference of the cored bar 11 is generally quite thin so that the heater heat can be quickly supplied to the outer surface of the material layer, that is, the outer peripheral surface of the fixing roller. (For example, about 0.5 mm). The layer material is generally PTFE (tetrafluoroethylene resin).
-Fluorine-based resin such as PFA (tetrafluoroethylene-fluoroalkoxyethylene copolymer resin) or heat-resistant and abrasion-resistant rubber such as silicone rubber is used.

The fixing roller coated with a fluorine-based resin has higher strength than that of a silicone rubber-coated fixing roller, and when silicone oil is applied, the releasability is also good. However, since the coating layer does not have elasticity, the fixing property of the toner image T on the surface of the image supporting material 5 is poor as compared with the fixing roller coated with silicone rubber, and the image is not formed when the toner image on the toner image supporting material is fixed. It has a drawback that the crushing effect is large and the image quality is degraded. Further, when the fixing roller has an abutting object such as a cleaning blade, when hard dust adheres to the roller and enters between the roller and the abutting object, there is no escape area for the force and a scratch is likely to occur.

In the case of the elastic coating such as silicone rubber, the difference in the fixing property is that the outer surface of the elastic coating corresponds to the unevenness of the surface of the supporting material 5 itself and the unevenness of the toner image T on the supporting material. It is considered that the fixing property is good because it is deformed and comes into contact with the uneven toner image T uniformly at each part. However, in the case of a rigid coating such as a fluorine-based resin, the convex portion makes strong contact with the roller and the concave portion makes unstable contact with the roller due to the unevenness of the support material and the toner image. Will be very sweet.

Therefore, from the viewpoint of importance of image quality, as the fixing roller 1, there is a tendency to use a silicone rubber-coated fixing roller rather than a fluorine-based resin-coated one, and various improvement studies on the silicone rubber-coated fixing roller are actively conducted. It is being appreciated.

As one of them, for the purpose of improving releasability and maintaining the releasability for a long time (longer roller life), a toner releasing aid is previously formed on the coating rubber layer 12 of the silicone rubber coating fixing roller 1. There is also one in which a silicone oil is used as the pressure roller 2, and the pressure roller 2 is also one in which the coating rubber layer 22 of the pressure roller 2 is made to contain the silicone oil in advance.

The silicone oil-containing rubber can be obtained, for example, by providing a swelling step after rubber vulcanization to allow silicone oil to permeate and be contained in the vulcanized rubber meat, or by adding and blending the silicone oil during kneading of raw rubber.
An example of obtaining a rubber-covered roller containing silicone oil by the swelling method is as follows. A raw rubber mixture obtained by mixing a silicone raw rubber with a cross-linking agent and, if necessary, a filler (silica etc.) and other additives is formed into a sheet. Then, it is wrapped around the outer periphery of the roller core metal through a primer and adhered. It is placed in a press mold and heated / pressurized for vulcanization. Silicone rubber is generally of the thermal vulcanization type (HTV) or addition reaction type (LTV). In the case of the thermal vulcanization type, the organic peroxide, which is a crosslinking agent, is decomposed and vulcanized at the stage of primary vulcanization. A decomposition residue is produced at the same time as sulfurization. Therefore, a secondary vulcanization treatment is performed to remove this. Even in the case of the addition reaction type, the characteristics are more stable when subjected to high temperature heat treatment. Then, the coating layer vulcanized roller is immersed in silicone oil to impregnate the coating layer with silicone oil. If the thickness of the coating layer at this oil immersion step is considerably thicker than the required thickness, the oil may be immersed in the oil after grinding to a substantially required thickness. After the completion of the oil immersion, the outer periphery of the coating layer is ground to finish the roller having a predetermined outer diameter. The oil immersion condition is not particularly limited, but for example, the coating layer 12
In the case of the fixing roller 1 having a thickness of 0.5 mm, the oil temperature is generally about 180 ° C. and the immersion time is 8 to 24 hours. The thickness of the coating layer 22 is thicker than that of the fixing roller (for example, 5 m).
m) In the case of the pressure roller 2, the immersion time is extended to, for example, about 2 days.

The silicone oil for impregnating the coating layers 12 and 22 of the rollers 1 and 2 is selected and used from the range of, for example, about 20 to 1000 cs in order to permeate the oil into the meat quality of the coating. Those of 20 cs or less are not suitable because they have good permeability into the coated meat but have poor heat resistance and volatilize and disappear due to heat from the fixing roller. Those with a high viscosity of 1000 cs or more are not effective because they have poor penetrability into the coating meat and require a long time for oil immersion treatment, and even when impregnated, they bleed to the coating surface. For the fixing roller, the amount of silicone oil to be impregnated into the coated meat should be 10% or more when the equilibrium swelling (saturated impregnation) of the oil with respect to the coated meat is 100%. The extension effect is low.

In this specification, the viscosity number (cs, centistokes) of silicone oil is 25 ° C. Further, the oil is not an oil prepared by blending silicone oils having various viscosities to adjust its viscosity number, but one having a single viscosity peak from the beginning is synthetically produced.

As described above, the use of the rubber-coated fixing roller 1 in which the coating rubber layer 12 contains silicone oil beforehand improves the releasability as compared with the case where the coating layer does not contain silicone oil, and The releasability is maintained for a long time, that is, the roller life is extended.

However, the long-lasting effect of the roller life is still unsatisfactory in practice. That is, as a conventional example, a fixing device having the following specifications was tested.

Fixing roller 1: φ60mm, 0.5mm thick silicone rubber coating, 100cs dimethyl silicone oil (Product No. KF96, Shin-Etsu Chemical Co., Ltd.) dipping treatment at 180 ℃ for 8 hours, heating use temperature (surface temperature) 180 ℃.

Pressure roller 2: φ60 mm, 5 mm thick silicone rubber coating, 10
180 ℃ × 4 in 0cs dimethyl silicone oil (same)
Immersion treatment for 8 hours.

Oil coating device 3: web system as shown in the first figure, product name Nomex paper web (nonwoven fabric), impregnated with 10,000 cs dimethyl silicone oil (product number K96H, same), web feed speed 1 m / 10,000 sheets (A4 version) Paper passing.

Paper passing speed: 50 sheets / minute Nip width W of the fixing roller 1 and the pressure roller 2: 9 to 10 mm The following tests (1) and (2) were conducted.

(1) Forced jam test The unfixed toner image supporting material 5 is successively introduced between the fixing roller 1 and the pressure roller 2, and at each time when a predetermined number of sheets are passed, the rollers 1 and 2 are then passed. The image supporting member 5 is sandwiched between the rollers 1 and 2 as it is, and the rollers 1 and 2 are placed.
Stop the rotation drive for 1 minute. Roller 1 for this 1 minute
The toner image portion of the image supporting material 5 portion sandwiched between the rollers 1 and 2 is forcibly offset to the surface of the nip width W area of the fixing roller by stopping the rotation drive of 2. After 1 minute, the rollers 1 and 2 are returned to the rotating state. Then, it is observed whether or not the forcibly offset toner on the surface of the fixing roller 1 has been wiped and removed from the surface of the fixing roller when passing through the oil applying device 3 which also serves as cleaning. When the offset toner has been wiped off, the operation of continuing the paper feed as it is until the next forcible offset treatment number of sheets is repeated, and finally the number of sheets at the time of sheet passing when the offset toner is not wiped off by the apparatus 3 is obtained.

This forced jam test itself is not directly related to normal line copying, but toner adheres to the roller and causes an offset, so the toner offset to the fixing roller 1 surface by the forced jam test is not wiped off by the device 3. The phenomenon in which the toner strongly adheres to the surface of the fixing roller starts to occur, the shorter the number of sheets of paper passing, the shorter the roller life, and conversely, the longer the number of sheets, the longer the roller life.

(2) Paper passing life test Unfixed toner image support 5 is introduced between the fixing roller 1 and the pressure roller 2 one after another, and the toner on the surface of the fixing roller 1 is gradually reduced due to the successive decrease in releasability due to the use of the fixing roller 1. Of the toner image supporting material around the fixing roller (that is,
Observe the presence of jams. Then, the number of sheets to be passed until the deterioration of the quality reaches a practically permissible limit or a jam frequently occurs is obtained.

The test results of the above (1) and (2) are shown in the conventional example column of Table 1. That is, the forced jam test is about 23,000 to 28,000 sheets, and the paper passing life test is about 100 to 150,000 sheets, which is still insufficient and it cannot be said that the performance is satisfactory.

As described above, according to the present invention, the rubber-coated fixing roller and the rubber-coated pressure roller, which are in contact with the toner image surface, are pressed and brought into contact with each other to rotate and drive the unfixed toner image support material so that the toner image is formed. Fix, at least the rubber coating of the fixing roller contains silicone oil in advance,
Separately, a toner image fixing device equipped with means for applying silicone oil little by little to the rubber-coated outer peripheral surface of the fixing roller is further improved to make it possible to significantly extend the roller life as compared with the conventional one. The silicone oil applied to the outer surface of the rubber coating of the fixing roller is the first oil having a viscosity close to or lower than that of the silicone oil previously contained in the rubber coating of the fixing roller. It is characterized in that the second oil having a viscosity higher than that of the first oil is used.

That is, the present inventors conducted the following experiments in the course of development and research of the present invention.

Experiment 1: Oil content transfer experiment Two tests in which two silicone oil-containing silicone rubber test pieces A and B having the same swelling degree (content rate) of silicone oil or different from each other were left in a contact pressure state. The behavior of the contained oil between the pieces was investigated. In this experiment, the test pieces A and B were made of the same quality silicone rubber,
The contained silicone oil was 100 cs dimethyl silicone oil (product number K96, Shin-Etsu Chemical Co., Ltd.). Table 2 shows a few examples thereof.

The following results were obtained from this experiment.

(1) In samples having the same oil swelling degree, mutual migration of the contained oil with time does not occur between them.

(2) If the oil swelling degrees are different from each other, the oil on the sample side having a high oil swelling degree moves to the sample side having a low oil swelling degree.

Experiment 2: Investigation of migration of contained oil in conventional device As shown in Fig. 2, a fixing device with the same specifications as those used in the above-mentioned forced jam test / paper passing life test, a size smaller than the maximum size that can be passed is undetermined. The deposited toner image support material 5 is successively introduced by one-sided reference transport on the right or left, and 30,000 sheets of paper are passed. In this case, the degree of swelling of silicone oil (initial degree of swelling) in each of the rubber coating layers 12 and 22 of the fixing roller 1 and the pressure roller 2 before the start of paper feeding was measured (extraction method). The results are shown in Table 1.

Further, the fixing roller 1 is in contact with the surface of the image supporting material 5 that has passed through the paper, and the peripheral portion of the roller which does not pass through the paper passing portion P or the image supporting material 5 is always in direct contact with the surface of the pressure roller 2 and is rotating. The roller peripheral surface area outside the paper passing portion is referred to as a non-paper passing portion Q.

Then, the degree of swelling of silicone oil in the rubber coating layer at both the paper passing portion P and the non-paper passing portion Q of the fixing roller 1 was measured after passing 30,000 sheets. The results are shown in Table 1.

That is, the degree of oil swelling of the rubber coating layer 12 of the fixing roller 1 is 62% in both the paper-passing portion P and the non-paper-passing portion Q in the initial stage, but after passing 30,000 sheets, the paper-passing portion P is 29%. Swelling, and the non-sheet passing portion Q decreased to 38%. The decrease in the degree of oil swelling in the non-sheet passing area Q is 3 according to the findings of Experiment 1 above.
The rubber coating layer 12 surface of the fixing roller 1 is in direct pressure contact with the rubber coating layer 22 surface of the pressure roller 2 continuously during the passage of all the sheets, and the rubber coating layer 12 of the fixing roller 1 having a large oil swelling degree. This is because the oil content therein has migrated to the rubber coating layer 22 side of the pressure roller 2 having a small oil swelling degree. One reason for the decrease in the paper passing portion P is that a very small amount adheres to the surface of each image supporting member 5 that has passed and is carried away, but this is not so much in quantity and is the main cause. Is a fixing roller 1 and a pressure roller 2 at a sheet passing interval of each image supporting member 5.
Every time when and are brought into direct pressure contact with each other, the contained oil moves from the rubber coating layer 12 side of the fixing roller 1 to the rubber coating layer 22 side of the pressure roller 2 as in the case of the non-sheet passing portion Q. Because there is.

In the case of a practical machine, there is almost no case where continuous 30,000 sheets of paper are passed as in Experiment 2 above. There are many total periods in which and are in direct pressure contact over the entire length. Therefore, in practical machines, the degree of decrease in the degree of oil swelling in the rubber coating layer 12 of the fixing roller 1 seems to be higher than that in Experiment 2.

In the conventional apparatus, the initial oil swelling degree of the rubber coating layer 12 of the fixing roller 1 and that of the rubber coating layer 22 of the pressure roller 2 are large in the former and small in the latter. The layer 12 has a small layer thickness and can be made to have a high degree of oil swelling by an oil immersion treatment for a relatively short time, whereas the rubber coating layer 22 of the pressure roller 2 has a large layer thickness. For this reason, in order to obtain a high degree of oil swelling, it is necessary to carry out the oil immersion treatment for many days, and the pressure roller 2 comes into contact with the back surface of the unfixed toner image supporting material 5, and thus the fixing is performed. This is because from the viewpoint that the toner releasability required for the roller 1 is not required so much, the oil immersion treatment is performed for about 2 days at the most in view of manufacturing cost.

Therefore, according to the above Experiments 1 and 2, the reason why the effect of prolonging the roller life of the conventional fixing device using the silicone oil-containing processing roller is still unsatisfactory is as follows.
The silicone oil in the rubber coating layer 12 of the fixing roller 1 migrates to the rubber coating layer 22 side of the pressure roller 2 over time, and the degree of oil swelling in the rubber coating layer 12 of the fixing roller 1 decreases.
That is, it was clarified that the mold releasability was lowered relatively early.

Therefore, according to the present invention, even if the oil content contained in the fixing roller rubber coating 12 migrates to the pressure roller rubber coating 22 side over time, the transferred oil content is sequentially replenished and impregnated into the fixing roller rubber coating 12 over time. The oil content of the fixing roller rubber coating 12 is kept substantially at the initial content for a long period of time, or the decrease of the content over time is slowed down as much as possible to extend the roller life significantly. is there. As a specific means for sequentially replenishing and impregnating the fixing roller rubber coating 12 with silicone oil over time, attention is paid to means 3 for gradually applying silicone oil to the outer peripheral surface of the fixing roller. As described above, the fixing roller rubber coating has a first oil having a viscosity close to or lower than the viscosity of the silicone oil contained in advance and a second oil having a viscosity higher than the first oil.

When such a blended oil of the first and second oils is used, the second oil component of the blended oil that is gradually applied to the outer peripheral surface of the fixing roller 1, that is, the outer peripheral surface of the rubber coating 12, has a high viscosity, that is, a molecular weight. Since it is large, it hardly penetrates into the meat quality of the rubber coating 12 and acts exclusively as a liquid for coating the outer peripheral surface of the rubber coating. On the other hand, the first oil component has a viscosity close to or lower than the viscosity of the oil previously contained in the rubber-coated meat, that is, it can be permeated and diffused into the rubber-coated meat in terms of molecular weight.
It acts as a liquid that sequentially supplements the lost oil amount that is sequentially transferred from the rubber coating 12 to the rubber coating 22 side on the pressure roller 2 side with time.

As a result of the successive permeation replenishment action of the first oil on the fixing roller rubber coating, the fixing roller rubber coating 12 can be removed even if the originally contained oil migrates from the fixing roller 1 side to the pressure roller 2 side with time. The oil content is substantially maintained at the initial content over a long period of time, or the decrease in the content over time is slowed down as much as possible, which can greatly extend the roller life. Also, the obtained fixed image is a soft image and has a good fixing property, and sufficient fixing can be performed even if the fixing temperature is set to about 5 to 10 ° C. lower than that of a fixing roller coated with a fluorine resin. It becomes possible to obtain an energy saving type device.

The silicone oil to be contained in advance in the rubber coating 12 of the fixing roller 1 and, if necessary, the rubber coating 22 of the pressure roller 2 should be selected and used from the range of about 20 to 1000 cs for the same reason as described in the above-mentioned conventional apparatus. Is. The initial degree of swelling of the rubber with the oil should be 10% or more.

Therefore, the first oil component of the oil applied to the outer peripheral surface of the fixing roller rubber coating is selected from the above viscosity range and has a viscosity close to or lower than the viscosity of the oil contained in the fusing roller rubber coating flesh. Assuming that the viscosity of the oil contained in the rubber-coated meat of the fixing roller is η, the first oil in the oil applied to the outer peripheral surface of the fixing roller preferably has a viscosity equal to or lower than the viscosity η. The viscosity of 1 oil may be larger than the viscosity η by an upper limit of 400cs, and more preferably 200 to 300cs. this is,
This is because it is a range in which the oil of viscosity η in the fixing roller rubber coating can permeate into the exuded portion.

The second oil has a higher viscosity than the first oil,
For example, it is selected and used from 1000cs or more.

Further, the mixing ratio of the first and second oils should be in the range of 5 to 40 parts by weight when the second oil is 100 parts by weight. That is, when the amount is 5 parts by weight or less, the replenishment amount of the first oil in the fixing roller rubber coating 12 with time is too small to obtain a good roller life extension effect. On the contrary, 40
When blending a large amount by weight or more, the content of silicone oil in the fixing roller rubber coating 12 increases over time due to over-replenishment, and eventually reaches 100% swelling state, and the high content is maintained. This causes problems such as an increase in layer thickness due to excessive swelling of the rubber coating 12, surface wavy deformation (which causes wrinkles on copy paper), bleeding of the excessive replenishing liquid, and deterioration of the quality of the fixed toner image due to the bleeding liquid.

Example A device according to the present invention was constructed by using, as the web member 31 of the oil applying device 3 impregnated with the following blended silicone oil, in the fixing device having the specifications mentioned above as the conventional example. Then, with respect to this fixing device, the forced jam test of (1) and (2), the paper passing life test, and the oil migration investigation in Experiment 2 were conducted. The results are shown in the Example column of Table 1.

That is, in comparison with the conventional example, the results of the forced jam test and the paper passing life test are remarkably good, and the result of the oil content transfer investigation is 30,000 sheets of paper, and the fixing roller rubber coating layer 12
The degree of oil swelling of both the paper passing portion P and the non-paper passing portion Q is obviously smaller than that in the case of the conventional apparatus (accurately, a very small amount of oil is transferred from the fixing roller to the copy paper every time. However, the releasability is maintained by this, and the fixing device was an excellent fixing device having a sufficiently long roller life.

Further, in the embodiment of the present invention, the fixing roller 1 and the pressure roller 2 are continuously rotated for 100 hours, and the rollers 1 and 2 are kept in the direct contact pressure rotation state without passing the paper during that time. No. 1 was heated and maintained at a predetermined temperature controlled temperature of about 180 ° C. and the oil swelling degree of the rubber coating of the fixing roller after 100 hours was measured, and it was found that the initial oil swelling degree was maintained.

The coated rubber used for the fixing roller and the pressure roller in Table 1 and the rubber used for the test piece 2 and B in Table 2 are all 100% swell (equilibrium swell / saturated swell) with 100 cs oil. The oil content (saturated content) per 100g of rubber is 30g, and that for 300cs oil is 15g.

[Brief description of drawings]

FIG. 1 is a cross-sectional side view showing a very schematic structure of a heat roller type toner image fixing device, and FIG. 2 is a perspective view of a fixing / pressurizing roller pair. Reference numeral 1 is a fixing roller, 2 is a pressure roller, 3 is a release aid coating device, 5 is an unfixed toner image supporting material, and T is an unfixed toner image.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shuji Ima 2-1-1 Oda Sakae, Kawasaki-ku, Kawasaki-shi, Kanagawa, Showa Electric Wire & Cable Co., Ltd. (72) Hisashi Akabane 2 Sakae Oda, Kawasaki-ku, Kawasaki-shi Showa Electric Wire & Cable Co., Ltd. (71) Susumu Hirai Inventor Susumu Hirai 2-1-1, Oda Sakae, Kawasaki-ku, Kawasaki-shi, Kanagawa (56) Reference: JP-A-52-124338 ( JP, A) JP 55-90983 (JP, A) JP 60-135976 (JP, A) JP 60-135977 (JP, A) Actual development JP 54-55344 (JP, U) JP Sho 63-45111 (JP, B2)

Claims (4)

[Claims] 1. A rubber-covered fixing roller in contact with a toner image surface and a rubber-covered pressure roller are pressed into contact with each other to rotate and drive, and an unfixed toner image support material is introduced between the rollers to fix the toner image. In a toner image fixing device equipped with a means for preliminarily containing silicone oil in at least the rubber coating of the fixing roller and applying little silicone oil to the rubber coating outer peripheral surface of the fixing roller separately, The silicone oil applied to the outer peripheral surface of the coating has a first oil having a viscosity close to or lower than the viscosity of the silicone oil previously contained in the rubber coating of the fixing roller, and a second oil having a viscosity higher than the first oil. A toner image fixing device characterized by the above. 2. The toner image fixing device according to claim 1, wherein the silicone oil previously contained in the fixing roller rubber coating has a viscosity at 25 ° C. of 20 cs or more and less than 1000. 3. The first oil has a blending ratio of 5 to 40 parts by weight with respect to 100 parts by weight of the second oil.
The toner image fixing device according to the item. 4. The toner image fixing device according to claim (1), (2) or (3), wherein the rubber coating of the fixing roller and the pressure roller is silicone rubber.