JPS5849977A - Offset preventing oil for pressurizing fixer - Google Patents

Abstract

PURPOSE:To prevent the toner adhesion and the offset, by applying a>=6C alcohol, which has a film forming property and contains 0-99% silicone oil, on the surface of a pressurized fixing roll of an electro-photographic device. CONSTITUTION:0-90% silicone oil is mixed with an alcohol having a film forming property of a >=6C alcohol such as dodecyl alcohol to obtain an offset preventing oil. An ethylalcohol is used to degrease the surface of each roll of a pressurizing fixer for electronic copying machine, and the offset preventing oil impregnated in a felt is uniformly applied on the surface of each roll. The preventing oil has a high affinity to the surface of the roll and forms a strong film to be adhered to the surface of the roll. A zinc oxide photosensitive paper having an unfixed toner image is allowed to pass through rolls continuously, and the toner image is fixed with pressure. The toner is not stuck to the surface of fixing rolls and stains it, and the offset is prevented to execute the pressurized fixing continuously for a long time.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an anti-offset oil for a pressure fixing device such as an electrophotographic device.

Conventionally, when a toner image is pressure-fixed onto a recording paper using a pressure fixing device in an electrophotographic device, the toner adheres to the surface of a pressure-fixing roll, and as this roll rotates, the toner attached to this roll is transferred to the recording paper. Sometimes, it adheres to and becomes fixed (called offset).

In order to prevent this, silicone oil or the like, which has a high releasability for toner, has been applied to the roll surface as an anti-offset oil. However, even if silicone oil or the like having high mold releasability is used, there is a problem in that offset occurs when the pressure fixing device is used an increased number of times.

The fewer the number of times the pressure fixing device is used before this offset occurs, the more it costs to maintain the pressure fixing device, and furthermore, the reliability of the electrophotographic device is impaired.

SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to provide an offset prevention oil for a pressure fixing device that significantly increases the number of times the pressure fixing device is used before offset occurs.

The anti-offset oil for a fixing device of the present invention has film-forming properties, contains 90 to 90% silicon, has a hydrophilic group, and has a carbon number of 6 or more.The present invention will be described in more detail.

Conventionally, silicone oil with high mold releasability has been used as an offset prevention oil for pressure fixing devices, but the present inventors conducted experiments and discovered that silicone oil was used instead of alcohol with a hydrophilic group and a carbon number of 6 or more. It has been discovered that a 90% mixed oil is more effective in preventing offset than the aforementioned silicone oil with high mold release properties.

This is called Z alcohol, which has a hydrophilic group and has film-forming properties, and is surface-treated with chrome plating to give it mechanical strength. It is thought that this oil has an affinity with the surface and forms a strong film, so a small amount of this oil is enough to coat the roll surface, and this oil makes it difficult for toner to adhere to the roll surface. In the present invention, the term "alcohol that has film-forming properties" is not necessarily limited to alcohols that have film-forming properties by themselves, but also includes alcohols that have film-forming properties even when mixed with silicone oil. . .

Normally, in an environment where an electrophotographic device is used, the alcohols shown in Table 1 are used as aliphatic saturated alcohols, but the alcohols are not limited to these, and for example, alicyclic alcohols may also be used, and unsaturated alcohols may also be used. Of course, alcohol may also be used. Furthermore, it is also possible to use a mixture of 0 to 90 g of silicone oil with these alcohols.

As explained above, the pressure fixing device prevention oil of the present invention can maintain the effect of preventing off-ceratra for a long period of time with a small amount.

Example Ricoh Company! ! ! ! Clean the surface of each roll of the pressure fuser for p'rsio copiers with paper containing ethyl alcohol to remove residual oil, and then test the rolls that come into contact with felt rollers and toner images containing the anti-offset oil shown in Table 2. The roll was pressed against the roll and idled for 1 minute to uniformly apply anti-offset oil to the roll surface. The felt at this time had a width of 16 mm, a thickness of 4 mm and a length of 25011 mm, and was uniformly impregnated with an anti-offset oil listed in Table 2 of LCC.

20 sheets of zinc oxide photosensitive paper with partially unfixed toner images are passed through the pressure fixing device uniformly coated with the offset prevention oil shown in Table 2, and pressure fixing is performed. I suspected that it would occur.

Table 2 below shows the results obtained from the above observations.

Table 2 Alcohols were found to maintain their anti-offset ability for a longer period of time than silicone oil.

Claims (1)

[Claims] Offset prevention oil for pressure fixing devices consisting of alcohol with a carbon number of 6 or more that has film-forming properties and contains 0% to 90% silicone oil O