JPS585771A - Cleaning roller for heat fixing device - Google Patents

Abstract

PURPOSE:To obtain a titled roller by which heat resistance and compressive permanent set are improved and the moving of silicone oil to a fixing roller is performed easily, by impregnating and curing liquid organopolyciloxane to a roller consisting of an open-cell type plastic foam. CONSTITUTION:After liquid organopolysiloxane (e.g. a linear structure, etc. consisting essentially of diorganopolysiloxane) is applied or impregnated in a roller consisting of an open-cell type plastic foam (e.g. polyether polyurethane foam, etc.), this material is cured to obtain a cleaning roller to clean the toner which is offset on a fixing roller or a heat pressurizing roller of an electronic type copying machine. By such constitution, the heat resistance and the compressive permanent set of the roller is improved and a continuous operation is further prolonged as the moving of silicone oil to the fixing roller is performed easily in case of impregnating the silicone oil.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a cleaning roll for a heat fixing device of an electronic copying machine, specifically a cleaning roll for cleaning toner offset from a fixing roll or a pressure roll. @Fixing in an electronic copying machine involves passing the copy paper on which the toner image has been formed through the nip between the fixing roll and a backup roll that supports and presses it, thereby fixing the toner image onto the copy paper. This method is generally used because it is thermally efficient and safe. However, this method has the disadvantage that when the surface temperature of the fuser roll deviates from the fusing temperature range, toner adheres to the metering roll, which causes an offset phenomenon during subsequent copying. Even if the surface temperature is at an appropriate value, toner is generated gradually during long-term use, and when there is no copy paper in the nip, the toner adhering to the fixing roll is transferred to the pressure roll and then sent ( This has the disadvantage of staining the copy paper. For this reason, the fixing roll is provided with a heat-resistant release surface made of fluororesin, silicone rubber, etc., or coated with a 5ml agent such as silicone oil. However, even in this case, fine particulate toner of No. 9 (St) that cannot be seen gradually adheres, and eventually becomes coarse, and eventually becomes cloudy to cause off-sera) ILII.
A cleaning roll is provided in contact with this type of fuser roll. This cleaning roll is usually made of a room-temperature vulcanized 1t (RTV!M) whose surface hardness is smaller than that of the fixing roll.
l) Rolls made of silicone rubber or closed-cell silicone rubber sponge impregnated with silicone oil are used. However, this RTV material essentially has a strength of rh < 41 t, which causes a large compression set at high temperatures, resulting in the inconvenience of toner adhesion when used for a long period of time. On the other hand, if the viscosity of the silicone oil to be impregnated is low, this type of sponge can be impregnated relatively easily, but it has the disadvantage that more silicone oil than necessary leaches out during use, causing offset. On the other hand, if the molecular weight of the silicone oil is large, the impregnation efficiency is poor, so this sponge had the disadvantage that it was not possible to impregnate a large amount regardless of the molecular weight of the silicone oil. In addition, if you get stuck with this silicone sponge,
It is also possible to use closed cells that are made open by mechanical means such as compression, but since the open cells are forcibly broken by mechanical means, they are fragile and weak. The present invention relates to a cleaning roll for a heat fixing device that solves these disadvantages.This invention relates to a cleaning roll for a heat fixing device that solves these disadvantages. It is characterized by being formed by coating or impregnating it with and then curing it.

To explain this, the inventors of the present invention have conducted various studies regarding cleaning rolls for heat fixing devices, and have found that it is possible to use a foam material with an open cell structure in order to adsorb toner adhering to the fixing roll. However, if it is made of a plastic foam and is impregnated with a curable silicone resin and cured, its heat resistance and
The compression set is improved, and since it is an open cell type, impregnation with silicone resin is easy and the amount of impregnation can be increased.Furthermore, products with this hardened silicone layer can be impregnated with silicone oil. The present invention was completed by confirming that silicone oil can be continuously and easily replenished for each sheet of copy paper on the fixing roll.

If the plastic foam constituting the cleaning roll of the present invention is open-celled, the material is 4! Must be limited to this! For example, polyvinyl chloride, polyethylene! Examples include polystyrene and polyurethane, and this one has a cell count of 20.
It is preferable to use 11/25- or higher, and polyether polyurethane foam or Bossester polyurethane foam is preferable because it has good flexibility. However, this is a continuous porous structure in which the surface of powdery materials such as polyvinyl chloride, polyethylene, polystyrene, polyurethane, etc. is coated with a pervasive dressing or liquid organopolysiloxane, which will be described later, and the powdery material is agglomerated. In this case, the size of the powder particles can be made uniform by simple separation in advance, so that the particles can be homogeneous.
It gives you the advantage of getting things.

On the other hand, the liquid organopolysiloxane impregnated into this plastic foam may be either a linear structure mainly composed of diorganopolysiloxane or an organopolysiloxane with a face structure, which becomes a silicone rubber elastic body upon curing. It is preferable that the rubber material is a rubber material, and it is possible to use either a room-temperature cured layer or a heat-cured layer commercially available as RTV rubber. Note that these organopolysiloxane compositions may be used after being diluted with a solvent from the viewpoint of workability and processability, but from the viewpoint of 1) concentrated pollution, it is better to use them without a solvent. 1. Preferably, the RTV rubber composition has a high viscosity.

The viscosity should be less than 10,000c8 (at 25°C) so that it can be coated or impregnated into plastic foam (if it is diluted with a solvent, it can contain at least 5-wt. weight organopolysiloxane, preferably 20 wt. % or more.

This liquid polysiloxane can be impregnated into plastic foam by immersing the plastic foam in liquid organopolysiloxane, then pulling it out and squeezing out the excess with a roll, or by applying liquid organopolysiloxane to the surface of the plastic foam. It is sufficient to apply a sufficient amount to a roll coater, knife coater, etc. to impregnate the inside, and then dry and harden it at room temperature or under heat, but from the viewpoint of improving productivity,
That's so clever. The amount of organopolysiloxane impregnated into the plastic foam is determined by the amount of impregnation of the plastic foam in the roll. The plastic foam roll having the organopolysiloxane cured layer may have improved heat resistance and compression set due to the formation of this cured film. Therefore, when using this roll as a cleaning roll for the fuser roll, it will not deteriorate or deform due to heat even if it comes into contact with a heated fuser roll, and since it has an open cell structure, it will not deteriorate even after long-term use. There is no fear of offset occurring due to toner adhesion. tr... This thing is in contact with the foam surface or the cured film of organopolysiloxane, so
When impregnated with silicone oil, this silicone oil can be easily transferred to the fixing roll, which has the effect of further extending the continuous operation of the copying machine. Next, I will give an example of the present invention. ◎ Example (manufactured by WI4, No. 141) A heat wire-processed urethane raw material (manufactured by MTB Co., Ltd.) with a density of 30 ± 3 #/bait. 3. Cell #46
Cylinder III (261
A polyurethane foam composite of 31
Iig product KIC1400RTV CI'm Chemical Co., Ltd., product name) 100i1 is impregnated with toluene 150011, then tied with a roll, and then heated at 150°C.
◎Next, this silicone-treated polyurethane foam molded body was heated to 14 mm x 6 cranes x 3.
When a sponge roll was made by attaching it to a 4011 m aluminum shaft, the density of this material was 210 k.
g7m” and the amount of silicone coated is 190#/m
The sponge roll obtained above was immersed in silicone oil KF96 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) with a viscosity of LOOOc8 for 5 hours at room temperature.
A sponge roll containing kII/m" was obtained @ (Preparation of Material 1p#3) 1i was added to the silicone rubber composition used in the preparation of Material 1.
1140ORTV7) Alternative LQK, CI) Silicone com set g-Kg 1400 RTV 100m Silicone oil KF96 (mentioned above) so@ and toluene 1300
A sponge roll was made by attaching an aluminum shaft to a silicone-treated polyurethane foam molded product using hot warehouse materials from the same company. and silicone oil content is 210 kg7m”
Met.

(Cleaning Test) The cleaning test was conducted using the contact heat fixing device shown in the figure. This device is composed of a fixing roll, a pressure roll, and a cleaning roll.
Its surface is a heat-resistant release surface 2 made of a silicone rubber layer that hardens at room temperature, and an infrared lamp 6 is installed inside it, and this surface is maintained at 180°C, which is the appropriate fixing value, by a temperature sensor 4. has been done. The pressure roll b facing this has a room-temperature curable silicone rubber layer 6 with a hardness of 601 on its surface, and is pressed against the fixing roll at a pressure of 40 mm/23 G- to form a nip. The copy paper 8 on which the toner gII7 has been formed is fixed when passing through this nip, but since the cleaning roll 9 is in contact with the fixing roll 10, this keeps the surface of the fixing roll always clean. It is now possible to

In the cleaning test, materials 1 to 3 prepared above and a known silicone sponge roll were used as cleaning rolls in this device, and these were pressed against the fixing roll with a load of 5 to 5 to determine the number of copies until offset occurred. The results were as shown in the table below.

[Brief explanation of drawings]

The figure shows a longitudinal cross-sectional view showing how the cleaning roll of the present invention is used. 1... Fixing roll, 6... Infrared lamp, Minister...
Pressure roll, 7... Toner roller, 8... Copy paper, 9.
・Cleaning roll. Patent applicant Shin-Etsu Polymer Co., Ltd.

Claims (1)

[Claims] L. A cleaning roll for a heat fixing device, characterized in that a roll made of open cell plastic foam is coated with or impregnated with liquid organopolysiloxane and then cured.