JPS5939743B2 - Offset prevention liquid permeable roller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an anti-offset liquid permeable roller.

In electrophotography, one of the devices for fixing a toner image formed on a sheet is a contact heating type fixing device that uses a heating fixing roller that comes into direct contact with the toner image.

An example of the above-mentioned contact heating type fixing device will be described with reference to FIG. 1. The fixing roller 1 includes a hollow cored roller 2, an elastic layer 3 made of silicone rubber, for example, formed around the outer periphery of the hollow cored roller 2, and a built-in It consists of heater 4.

An anti-offset liquid such as silicone oil 6 is supplied to the surface of the roller 1 through a web 5. Further, a pressure roller 8 having a built-in heater T is in pressure contact with the fixing roller 1, and both rollers 1 and 8 are rotated in a sailor's direction. Now, when the sheet 10 on which the toner image 9 has been formed is conveyed in the sailor's direction and is held between the fixing roller 1 and the pressure roller 8, which rotate in pressure contact with each other,
The toner image 9 is melted and fixed on the sheet 10 by the pressure of the heater 4, T, and both rollers.

In the above fixing device, when the toner image on the sheet melts and becomes sticky, a part of it adheres to the surface of the fixing roller 1 and is transferred to the next sheet, which is the so-called offset phenomenon. occurs. In order to prevent this offset phenomenon, the silicone oil 6 is applied to the surface of the fixing roller 1 in the above device, but when the silicone oil 6 is supplied using the web 5,
This web 5 may become clogged with dust, melted toner, etc., resulting in an incomplete liquid supply function. Therefore, an anti-offset liquid supply device has been proposed in which a coating roller is disposed between the web 5A and the fixing roller 1, as shown by the reference numeral 11 in FIG. However, when the application roller 11 is used, there is a drawback that the anti-offset liquid is supplied in excess. By the way, when silicone rubber is used as the elastic layer of the fixing roller and silicone oil is further applied to it, the silicone rubber impregnates and retains the silicone oil, so that the release property of the roller, so-called offset prevention property, can be maintained. Are known.

This is thought to be because the silicone oil penetrates into the silicone rubber and is retained therein. An example of a heat fixing roller that utilizes the relationship between silicone rubber and silicone oil will be described with reference to FIG. It shows. A large number of oil passage holes 13 are provided on the circumferential surface of the core roller 12 . A silicone rubber layer 14 is formed on the outer periphery of the core roller 12 . Silicone oil 15 is supplied and held inside the core roller 12 . Note that the core roller 12 may be formed of a sintered alloy or porous porcelain having minute holes. When the anti-offset liquid permeation roller 16 constructed as described above is used as a fixing roller, the roller itself is impregnated with silicone oil, so there is no need to apply oil to the roller surface.

Then, the silicone oil 15 as the offset prevention liquid held inside the roller oozes out from the conduction hole 13 to the silicone rubber layer 14 as the offset prevention liquid permeation layer.
It penetrates into the rubber layer and exits to the outer surface, increasing the release effect of the silicone rubber to prevent offset. Also,
When an offset prevention liquid permeation type roller is used as a fixing roller, the heat source is one built into the pressure roller, one that heats the roller surface from the outside, or the core roller 12 is made into a double cylinder and a heater is arranged inside. (See Japanese Patent Application No. 1983-53323). The above-mentioned onset prevention liquid permeable roller skillfully utilizes the properties of silicone rubber and silicone oil, and maintains its offset prevention effect over a long period of time. 1
1, but if the silicone oil penetrates into the silicone rubber, it will swell and weaken the adhesion between the silicone rubber layer and the nenkin or shaft, and the diameter of the hole will increase, causing problems such as changing the paper feed speed. be.

The present invention provides an offset prevention liquid permeable roller,
A durable roller with suppressed swelling as much as possible by providing an anti-offset liquid control layer, an anti-offset liquid permeation layer on the outer periphery of the above layer, and an anti-offset layer as necessary to improve the anti-offset effect. The purpose is to provide a roller.

The present invention will be explained below with reference to illustrated embodiments.

In FIG. 3, an anti-offset liquid control layer 18 is provided on the outer periphery of the core roller 1r as an anti-offset liquid holding body.
is formed. This anti-offset liquid control layer 18 controls the anti-offset liquid 1 held in the core roller 1r.
Silicone rubber showing lipophilicity to silicone oil used as 9 and silicone rubber showing oil resistance used as 0.5
It is formed by blending at an appropriate ratio of ~99.5:99.5~0.5. For example, common silicone oils (methyl silicone rubber, methyl phenyl silicone oil) are different from common silicone rubbers (methyl silicone rubber, methyl silicone rubber,
Methylvinyl silicone rubber) has lipophilic properties, and fluorinated silicone rubber has oil resistance.

Furthermore, with respect to fluorinated silicone oil, general silicone rubber exhibits oil resistance, and fluorinated silicone rubber exhibits lipophilicity. By forming the anti-offset liquid control layer 18 as described above, the silicone oil in the core roller 1γ penetrates and passes through the oil-oleophilic silicone rubber and reaches the surface of the roller 20. to go out.

Next, a specific example of the anti-offset liquid control layer will be shown.

Example 1 KE1300 (Shin-Etsu Silicon) RTV...
(1) Shirastick 733 (Dow Corning)...
(2) Blend the above (1) and (2) at a ratio of 5:5.

Example 2 Torre silicone SH433Base...
... (3) Fluorinated silicone rubber LS-63V (Dow Corning) ...
・・・・・・・・・(4) 7:3 of (3) and (4) above
Blend in the ratio of

In addition to the above-mentioned offset prevention liquids,
Commonly used oils such as methyl chlorinated silicone oil and fatty acid-modified silicone oil can be used. The viscosity of the silicone oil is preferably 30CS to 1000CS, but may be 10CS to 1000CS. The control layer 18 can be formed by coating or by a general rubber molding method as long as it has a thickness of 2 μm or more.

The rubber hardness is desirably 10 to 90, but this may not be the case depending on how the roller is used. The ratio of silicone rubber to be blended is appropriately selected depending on the characteristics such as the viscosity of the silicone oil used. As described above, the permeation type roller has an anti-offset liquid control layer formed by blending silicone rubber exhibiting oil resistance and silicone rubber exhibiting lipophilicity with respect to the silicone oil used. The amount of silicone oil passing through is controlled, suppressing swelling as much as possible.

Therefore, the adhesion between the elastic layer and the metal core or shaft does not change, and a roller with good durability can be provided, and the diameter of the roller does not increase. When the roller having the control layer 18 shown in FIG. 3 is used as a fixing roller, the offset prevention effect is further improved by forming an offset prevention layer (not shown) on the outermost periphery.

Next, FIG. 4 shows a multi-layered anti-offset liquid permeable roller.

This roller 21 has a control layer 2 on the outer periphery of a core roller 22 having the same structure as the offset prevention liquid control layer 18 described above.
3 is formed, and on its outer periphery is an offset prevention liquid permeation layer 2 that is lipophilic to the silicone oil used.
4 is formed. Roller 2 configured in this way
1 as a fixing roller, the silicone oil coming out of the core roller permeates into the permeation layer 24 via the control layer 23, so that the silicone oil is impregnated and retained near the surface of the roller. In addition, the roller 21
When general silicone oil is used as the offset prevention liquid control layer 23, it may be formed of a thin layer of fluorinated silicone rubber or fluorine rubber.

Fluorinated silicone rubber and fluorine rubber, which exhibit oil resistance against general silicone oil, do not completely imperme oil, but if they are formed into a thin layer of about 1 μm to 0.5 μm, oil will pass through. According to experiments, 30 to 10
A considerable degree of penetration of general silicone oil into the 0μ layer was observed. As described above, according to the roller 21 in which the control layer and the permeation layer are formed, the amount of oil supplied to the permeation layer 24 is controlled by the control layer 23, so that the permeation layer 24 is prevented from being impregnated with an unnecessary amount of oil. There is no swelling of the permeable layer.

Furthermore, the permeation layer 24 that exhibits lipophilicity with respect to general silicone oil exhibits a volume change of 10 to 200% at 100 to 200°C, but fluorinated silicone or fluorine rubber exhibits a volume change of 10 to 200%.
．． It only shows a volume change of 5-5%. Therefore, the control layer 23 hardly changes, and the adhesion to the core roller 22 does not deteriorate. Further, according to the roller 21, silicone oil is impregnated and held near the surface, so even when copying at high speed or continuously copying a large number of sheets,
Oil is smoothly supplied to the surface of the mouth roller, and the offset prevention effect is not attenuated.

It goes without saying that the roller 21 shown in FIG. 4 may be provided with an offset prevention layer (not shown) on the outermost periphery.

Furthermore, if the control layer 23 and the permeable layer 24 are made of the same elastic material, preferably of the same type, the bond between the layers will be strong and the adhesion will not weaken even if the permeable layer swells. Furthermore, a reinforcing material for reinforcing the adhesion between each layer, such as a reinforcing layer wrapped around glass fiber, may be provided. As described above, according to the offset prevention liquid permeation type roller of the present invention in which a control layer for controlling seepage of the liquid is formed on the outer periphery of the offset prevention liquid holding body, swelling can be prevented without interfering with the supply of the offset prevention liquid. Since this can be suppressed as much as possible, it is possible to prevent the roller diameter from increasing and keep the paper feeding speed constant.

Further, according to a roller in which an offset prevention liquid permeation layer is formed on the outer periphery of the control layer, the supply of the offset prevention liquid to the roller surface, in other words, the offset prevention effect is improved.
What can be said about any roller is that by suppressing swelling, defects such as changes in diameter due to swelling and peeling of adhesive parts are eliminated, and it can be used for a long time, so-called durability. It is possible to provide a penetrating roller with a certain level of quality.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of a contact heating type fixing device, FIG. 2 is a longitudinal sectional view of an offset prevention liquid permeation type roller showing a conventional example of the present invention, and FIGS. 3 and 4 are in accordance with the present invention. FIG. 3 is a side sectional view showing an example of the offset prevention liquid permeable roller of FIG. 17, 22...Core roller 18, 23...
. . . Offset prevention liquid control layer, 24 . . . Offset prevention liquid permeation layer, 19 . . . Silicone oil as offset prevention liquid.

Claims (1)

[Scope of Claims] 1. An anti-offset liquid holding body that holds an anti-offset liquid so that it can seep out;
The anti-offset liquid is formed by blending a rubber that is oil-resistant to the anti-offset liquid and a rubber that is lipophilic, and is impregnated with the anti-offset liquid exuding from the holder and passes through this layer. An anti-offset liquid permeable roller consisting of an anti-offset liquid control layer that controls the amount of anti-offset liquid. 2. An anti-offset liquid holding body that holds the anti-offset liquid so that it can seep out, and an anti-offset liquid holding body formed on the outer periphery of the holding body,
The anti-offset liquid is formed by blending a rubber that is oil-resistant to the anti-offset liquid and a rubber that is lipophilic, and is impregnated with the anti-offset liquid exuding from the holder and passes through this layer. An anti-offset liquid permeable roller consisting of an anti-offset liquid control layer that controls the amount of anti-offset liquid, and an anti-offset liquid permeation layer formed on the outer periphery of this control layer and impregnated with the anti-offset liquid seeped from this control layer. .