JP2002278342A - Oil application roller - Google Patents

Abstract

(57) [Problem] To prevent oil leakage during transportation or storage, to apply evenly while controlling the amount of release oil to be supplied to the fixing roller while having a small and simple structure, and to release. To provide an oil application roller capable of increasing the utilization rate of mold oil. SOLUTION: An oil application layer 3 is provided on an outer periphery of an oil holding member 2 formed of a hollow cylindrical porous molded body, and oil release is performed by supplying release oil 6 held by the oil holding member 2 to a fixing roll. In the roller 1, the porous molded body 2
Is made of an inorganic material having fine pores and pores inside, and the fine pores at least partially communicate with the surface of the porous molded body and the pores, and the pores are at least partially partially filled with the fine pores. And communicate with the surface of the porous molded article through the
a m ^2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil application roller which is a component of a fixing device in an electrostatic copying machine, an electrophotographic printer or the like.

[0002]

2. Description of the Related Art In a fixing device such as an electrostatic copying machine or an electrophotographic printer, when fixing toner transferred onto a recording paper as a subject, toner may adhere to a heat fixing roll, and the toner may be removed. In order to prevent the next recording paper from being stained, apply a small amount of release oil such as silicone oil to the heat-fixing roll with an oil application roller, so that toner adheres to the heat-fixing roll or the recording paper adheres. To prevent it from rolling up. Various oil application rollers having such a function have already been provided.

For example, as shown in FIG. 6, a cylindrical molded body made of porous ceramic is used as an oil holding member b for storing a release oil to be applied, and the surface of the cylindrical molded body is made of heat-resistant felt. An oil transfer layer c and an oil application amount control layer d composed of a polytetrafluoroethylene (PTFE) porous film or the like are wound around the two layers c and d.
Is applied with a mixture of an adhesive and silicone oil. Also, as shown in FIG.
Using a cylindrical molded body composed of a hollow pipe with a hole made of metal e and storing release oil g in its oil holding tank f,
There is an oil application roller h on which the oil transfer layer c and the oil application amount control layer d are wound and adhered.

[0004]

However, in the oil application roller a of FIG. 6, the amount of release oil that can be used is limited due to the oil retention characteristics of the porous ceramic, and the amount of unused release oil is limited to the total amount of release oil. About half of the
Therefore, in order to make the oil application roller a having a long life,
It needs to be large. Further, when the temperature of the oil application roller a becomes high during use, the air contained in the porous ceramic oil holding member b expands, and the release oil may be discharged excessively.

In the oil application roller h shown in FIG. 7, when the air layer i formed in the oil holding tank f is slightly expanded, not only the release oil g is excessively discharged, but also the oil transfer layer c and The oil application amount control layer d peels off,
They may be destroyed. Further, since the oil application roller h has a structure in which a hole is formed in a metal pipe, there is no layer for holding the release oil. Therefore, if the device is placed vertically during transportation or storage, the hydraulic pressure is increased particularly in the lower portion, and the release oil may leak, which may lead to an unexpected accident. In addition, since the release oil is supplied from such an uncontrolled hole, discharge unevenness is likely to occur, and it is also difficult to control the amount of application, so that toner adheres to the heat fixing roll or recording paper adheres. There is a problem that the risk of rolling up increases.

Accordingly, it is an object of the present invention to provide a uniform coating while controlling the amount of release oil to be supplied to a fixing roller while maintaining a small and simple structure without causing oil leakage during transportation or storage. Another object of the present invention is to provide an oil application roller capable of increasing the use rate of the release oil.

[0007]

Under such circumstances, the present inventors have conducted intensive studies and as a result, have found that a hollow cylindrical oil holding member is hollowed out, for example, so that half of the entire volume is hollow. The utilization rate of the release oil can be improved from 50% to 75% of the conventional, and the hollow cylindrical oil holding member is a porous ceramic made of an inorganic material having fine pores and pores inside; If the air permeability is in a specific range, or if the porosity is in a specific range, after the release oil is filled, the hollow portion is in a reduced pressure state, and a balance with the capillary force occurs. During transport and storage, it was found that oil leakage did not occur, and that it was possible to apply evenly while controlling the amount of release oil supplied to the fixing roller while using a compact and simple structure during use. Which resulted in the completion of the Akira.

That is, in the present invention (1), an oil coating layer is provided on the outer periphery of an oil holding member formed of a hollow cylindrical porous molded body, and the release oil held by the oil holding member is supplied to a fixing roll. In the oil application roller, the porous molded body is made of an inorganic material having fine pores and pores therein, and the fine pores are at least partially communicated with the surface of the porous molded article and the pores. At least a part of the pores communicates with the surface of the porous molded body through the fine pores, and the air permeability is 1%.
It is intended to provide an oil application roller having a pressure of 00 to 6000 Pa · s / m ² . With this configuration, the utilization rate of the release oil can be improved to about 75% with respect to 50% of the cylindrical oil holding member. After the release oil is filled, the hollow part is depressurized, and the balance with the capillary force occurs, so that oil does not leak even during transportation and storage. Can be applied evenly while controlling the amount of release oil to be supplied to the ink.

Further, according to the present invention (2), an oil coating layer is provided on the outer periphery of an oil holding member formed of a hollow cylindrical porous molded body, and the release oil held by the oil holding member is supplied to a fixing roll. The oil application roller
The porous compact is made of an inorganic material having fine pores and pores therein, and at least a part of the fine pores communicates with the surface of the porous compact and the pores. 40% or more of the diameter is 30 ~ 200μ
m, and at least a part of the pores communicates with the surface of the porous molded body through the fine pores, and has an average pore diameter of more than 200 to 2000 μm or less, and the total volume of the pores is Is 5 to 30% in the porous molded body.
The present invention is to provide an oil application roller which is present at a ratio of: The release oil is applied to the fixing roll by supplying the release oil held in the pores to the felt, which is an oil coating layer, through a fine-diameter gap by capillary force. For this reason, the amount of release oil supplied to the oil coating layer is
It can be adjusted by the porosity, and if the porosity is in the above range, it is possible to apply evenly while controlling the amount of release oil supplied to the fixing roller.

Further, according to the present invention (3), an oil coating layer is provided on the outer periphery of an oil holding member formed of a hollow cylindrical porous molded body, and the release oil held by the oil holding member is supplied to a fixing roll. The oil application roller
The porous molded body is made of an inorganic material having fine pores and pores therein, and the fine pores at least partially communicate with the surface of the porous molded body and the pores, and the pores are at least partially dispersed. Communicates with the surface of the porous molded body through the fine pores, and the pressure (P
₁ ) and the pressure difference (P ₁ −P ₂ ) between the atmospheric pressure (P ₂ ) and −0.
The present invention provides an oil application roller having a range of from 0.5 to -2.0 KPa. When the oil holding member is filled with the release oil, the release oil is held in the pores through the fine-diameter gap of the oil holding member. Reduce the pressure in the part. On the other hand, the release oil held in the pores moves to the felt, which is the oil application layer, through the microscopic voids due to the capillary force. When the degree of pressure reduction is within the above range, there is no excessive transfer of oil and no oil leakage even during transportation or storage in balance with the capillary force. The balance between the degree of depressurization of the hollow portion and the capillary force is maintained in the same balance even during use, and the amount of the release oil applied can be stably supplied without unevenness.

In the present invention (4), the oil coating layer comprises an oil transfer layer and an oil application amount control layer provided thereon, and both of these layers are made of a mixture of an adhesive and silicone oil. An oil application roller according to any one of the above (1) to (3), which is bonded. By adopting such a configuration, the amount of the release oil supplied to the fixing roller can be further uniformly controlled while controlling the amount.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to FIGS. FIG. 1 is a side view showing an installation state of an oil application roller according to an embodiment of the present invention in a fixing device, FIG. 2 is an axial sectional view of the oil application roller according to an embodiment of the present invention, and FIG. It is a sectional view in the diameter direction of an oil application roller which is an embodiment. In the drawing, reference numeral 1 denotes an oil application roller. The oil application roller 1 is provided with an oil application layer 3 on the outer periphery of an oil holding member 2, and is an application surface of the release oil held by the oil holding member 2, which will be described later. The oil holding member 2 is provided with a hollow portion 5, and the hollow portion 5 is filled with a silicone oil 6 as a release oil.
A pressure relief valve 17 is provided on a flange 14 for partitioning between the hollow portion 5 and the outside air to reduce a rise in minute pressure in the hollow portion 5. And this oil application roller 1
Is incorporated in the fixing device 10, and the fixing device 10
The recording paper 4 is placed between the heat fixing roll 11 and the pressure roll 12.
And the toner 1 transferred to the surface 4a of the recording paper 4
3 so that the toner 13 on the surface 4 a of the recording paper 4 does not adhere to the heat fixing roll 11.
The oil application roller 1 is brought into contact with the heat fixing roll 11, and the silicone oil 6 is applied to the peripheral surface of the heat fixing roll 11.

The oil holding member 2 is a hollow cylindrical porous molded body capable of holding the silicone oil 6, and is made of a heat-resistant inorganic material having fine pores and pores therein. The pores communicate with the surface of the porous molded body and the pores, and at least a part of the pores communicates with the surface of the porous molded body through the fine pores, and the air permeability is 100 to 6000 Pa · s. a / m ^2.
This porous molded body has a large oil retaining force due to the fine-diameter voids between the fibers, and the movement of oil due to capillary force is moderately adjusted by the pore group formed by burning out of the granular organic substance which is one raw material at the time of production described later. Therefore, it is possible to apply evenly while controlling the amount of the release oil, and it is possible to suppress oil leakage. The oil utilization rate is about 75% compared to 50% of the conventional columnar oil holding member.
And the utilization rate of the release oil can be improved. If the airflow resistance is less than 100 Pa · s / m ² , the oil will not have sufficient oil holding power and will easily flow out naturally. On the other hand, when the air permeability exceeds 6000 Pa · s / m ² , although the oil holding power is excellent, the oil is not smoothly transferred to the oil transfer layer, and the oil is not easily discharged. . The preferable range of the air permeability is 500 to 4000 Pa when the kinematic viscosity of the release oil is 50 to 300 cSt (25 ° C.).
S / m ² is preferable, and especially 2000 to 3000 Pa · s / m ²
Is preferred.

The heat-resistant inorganic material constituting the oil holding member 2 is an inorganic material which is chemically and mechanically stable under heating at 400 ° C. or higher, preferably 600 ° C. or higher. The heat-resistant inorganic material is not particularly limited, and examples thereof include a material formed by bonding heat-resistant fibers or a heat-resistant fiber and a water-resistant inorganic filler to each other with an inorganic binder.

The heat-resistant fiber is an inorganic aggregate that forms an inter-fiber space by being mutually bonded by an inorganic binder. Examples of the heat-resistant fiber include glass fiber, rock wool, aluminosilicate fiber, and alumina fiber. And the like. Of these, glass fiber is preferable because the fiber diameter is large and the heat resistance temperature is high. As the heat resistant fiber, one or a combination of two or more of the above can be used.

The water-resistant inorganic filler is an inorganic aggregate that fills the inter-fiber voids formed by bonding the heat-resistant fibers with the inorganic binder and adjusts the amount of the inter-fiber voids. Examples include powders such as silica, alumina, kaolin, bentonite, Frogme clay and Kibushi clay,
Those having a controlled particle size are preferred. As the water-resistant inorganic filler, one or a combination of two or more of the above can be used.

Examples of the inorganic binder include sodium silicate, colloidal silica, alumina sol, lithium silicate,
Glass frit and the like can be mentioned. Of these, sodium silicate is preferable because of its high strength at relatively low temperature firing. As the inorganic binder, one or a combination of two or more of the above can be used.

The gas permeability resistance is ASTM / C-522-8.
It is obtained by measuring according to 7. Specifically, an air permeability measuring device 40 shown in FIG. 5 is used. The device 4
0 is a cylindrical pressure vessel 44 having one end open and a differential pressure gauge 41
, A flow meter 42, and a compressor 43, a sample 45 air-tightly fixed in a cylindrical pressure vessel 44, a predetermined flow of air is sent to the sample 45, and the differential pressure is measured by the differential pressure gauge 41. Permeability (Pa · S / m ² ) = SP / TU (where S is the cross-sectional area m ² of the sample, T is the thickness m of the sample, P is the differential pressure Pa, and U is the flow rate. m ³ / s) to determine the airflow resistivity. FIG.
Where l ₁ is 20 mm and l ₂ is 30 mm. In addition, the ventilation resistance is determined by an average value at three points of the flow rate of 2.7, 5.4 and 8.4 cm ³ / min.

The oil holding member formed of a hollow cylindrical porous molded body is a porous ceramic having fine pores and pores inside, and has fine pores and pores inside. The fine pores have a substantial pore diameter of 1 to 200.
μm, and in particular, the proportion of the pores whose pore diameters are distributed in the range of 30 to 200 μm is at least 40% of the volume of all the fine pores present inside the porous molded body, Preferably at least 50%, more preferably 6%
It accounts for more than 0%. If the proportion of the volume of the all fine pores is less than 40%, the transfer speed of the release oil is reduced, which is not preferable. At least a part of the fine voids among all the fine voids existing inside the porous molded body communicates with the surface and the pores of the porous molded body.

The pores have an average pore diameter exceeding 200 μm and
It is a spherical or elliptical cavity having a diameter of not more than 00 μm, preferably 300 to 500 μm, and is preferably substantially uniformly dispersed in the porous molded body. Average pore size is 200μm
If the ratio is less than the above, the difference between the pore diameter of the fine pores and the pore diameter of the felt layer is small, and the capillary force from the pores to the surface of the porous molded body is not preferable. Also, 2000μ
If it exceeds m, the holding power of the release oil is extremely reduced to cause liquid leakage, and the time-dependent change in the release oil application performance becomes large, so that the application performance cannot be stably exhibited for a long time, which is not preferable. As for the pores, at least a part of all pores present inside the porous molded body communicates with the surface of the porous molded body through the fine pores.

The ratio of the total volume of the pores to the bulk volume of the porous molded body (pore ratio) is 5 to 30%, preferably 10 to 20%. When the porosity is less than 5%, the amount of oil transferred to the felt is small, and the oil followability to the felt is reduced, so that it is difficult to smoothly apply the oil. On the other hand, if the porosity exceeds 30% in the porous molded body, the structure has too low a gas-permeation resistivity, lacks oil holding power, and tends to flow out undesirably. The ratio of the total volume of pores and voids to the bulk volume of the porous molded body (also referred to as the total porosity) is:
Preferably 40-90%, more preferably 60-80
%. When the total porosity is within the above range, the oil transfer power and the oil holding power increase, which is preferable. The pores and fine pores of the porous ceramic can be observed with a SEM (scanning electron microscope) of the fracture surface of the porous molded body.

The oil holding member made of a hollow cylindrical porous molded body has a pressure (P ₁ ) and an atmospheric pressure (P ₁ ) in the gas phase of the hollow portion in a state where the release oil is held in the hollow portion. P
₂ ) The differential pressure (P ₁ -P ₂ ) is -0.05 to -2.0 KP
a, preferably in the range of -0.2 to -1.0 KPa.
When the pressure difference (P ₁ −P ₂ ) is in the range, the balance between the oil holding property and the oil application property is improved. That is, when the oil holding member is filled with the release oil, the release oil is held in the pores through the fine diameter gap of the oil holding member. At this time, a part of the air in the hollow portion is also drawn in. The pressure in the hollow part is reduced. On the other hand, the release oil held in the pores moves to the felt, which is the oil application layer, through the microscopic voids due to the capillary force. When the degree of decompression is within the above range, there is no excessive oil transfer and no oil leakage even during transportation or storage in balance with the capillary force. The balance between the degree of depressurization of the hollow portion and the capillary force is maintained in the same balance even during use, and the amount of the release oil applied can be stably supplied without unevenness. The release oil is usually a low-viscosity silicone oil of about 50 to 300 cSt (25 ° C.), preferably about 100 cSt (25 ° C.).

Next, a method of manufacturing an oil holding member formed of a hollow cylindrical porous molded body will be described. As a method for producing the oil holding member, for example, an average fiber diameter of 6 to
30 μm, heat resistant fiber 10 having an average fiber length of 0.1 to 10 mm
0 parts by weight, 5-300 parts by weight of inorganic binder, organic binder 1
To 100 parts by weight, 1 to 300 parts by weight of water-resistant particulate organic matter,
And a kneaded product composed of 50 to 300 parts by weight of water and formed into a hollow cylinder, dried, degreased, and fired at 400 to 1500 ° C. In the porous molded body, the fine pores are formed by the voids formed between the fibers and the voids formed by the disappearance of the moisture, and the pores are formed separately by burning out the water-resistant particulate organic matter.

Examples of the heat-resistant fiber include the same materials as those exemplified in the description of the oil holding member. The heat-resistant fiber has an average fiber diameter of 6 to 30 μm,
It is preferably 5 to 15 μm, and the average fiber length is 0.1 to
It is 10 mm, preferably 1 to 6 mm. It is preferable that the average fiber diameter and the average fiber length are within the above ranges because both the oil transfer power and the oil holding power are high. The heat-resistant fibers can be used alone or in combination of two or more.

Examples of the inorganic binder include those similar to those exemplified in the description of the oil holding member. The inorganic binder can be used alone or in combination of two or more of the above. The amount of the inorganic binder is 5 to 300 parts by weight, preferably 30 to 100 parts by weight, based on 100 parts by weight of the heat resistant fiber. When the amount is within the above range, the strength of the oil holding member is high and the necessary fine pores are obtained, which is preferable.

The organic binder imparts strength to the molded product when the kneaded material of the oil holding member is formed and dried, and increases the viscosity of the kneaded material to facilitate molding. . Examples of the organic binder include methylcellulose, carboxymethylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, polyvinyl alcohol, phenolic resin, polyacrylate, and sodium polyacrylate. The organic binder can be used alone or in combination of two or more. The compounding amount of the organic binder is 1 to 100 parts by weight, preferably 5 to 30 parts by weight, based on 100 parts by weight of the heat-resistant fiber. When the amount is within the above range,
It is preferable because the elongation during molding is good. Note that the organic binder disappears during firing.

The water-resistant particulate organic matter is present in the form of a granulated mixture of the raw material of the oil holding member in a dried state, but disappears during firing to form pores in the oil holding member. Things. Examples of the water-resistant granular organic substance include, for example, polyethylene, polypropylene, polystyrene, synthetic resins such as acrylic resin, water-resistant natural materials such as wood, and substantially granular substances such as carbon powder. Are preferred because of many types and inexpensiveness. The synthetic resin particles may be foams. Water-resistant particulate organic matter has an average particle size of 200μ
m to 2000 μm or less, preferably 300 to 50
0 μm. It is preferable that the average particle diameter is within the above range, since the releasing oil holding force of the oil holding member is increased.
The water-resistant granular organic substance can be used alone or in combination of two or more of the above. The compounding amount of the water-resistant granular organic substance is preferably 1 to 300 parts by weight based on 100 parts by weight of the heat-resistant fiber. If the amount is changed within the above range, the oil transfer amount of the oil holding member can be controlled.

In the method for manufacturing the oil holding member, first, the raw material is kneaded with water to obtain a kneaded material. The amount of water varies depending on the type of the molding method, but is preferably 50 to 300 parts by weight based on 100 parts by weight of the heat-resistant fiber.
Next, the kneaded material is formed into a hollow cylindrical shape. The molding method is not particularly limited, and examples thereof include extrusion molding and press molding. Next, the obtained molded body is dried at normal temperature or under heating. At this time, moisture is removed from the molded body to form inter-fiber voids. As the drying condition, a condition in which the moisture content of the molded body is 0% is adopted. For example, when the molded body is dried under heating, the drying temperature is usually 50 to 150 ° C, preferably 80 to 120 ° C. When the drying temperature is within the above range, the organic binder and the water-resistant particulate organic matter can be dried in a short time without decomposing and disappearing, which is preferable. Further, when the molded body is liable to be deformed or cracked during drying, the humidity of the drying atmosphere and the amount of compounding water may be appropriately adjusted.

Next, the dried molded body is degreased by heating in an electric furnace or the like, and then fired to obtain a porous molded body. At this time, the water-resistant particulate organic matter and the organic binder in the molded body disappear, and pores are formed in the disappearance trace of the water-resistant particulate organic matter. In addition, at the time of degreasing, air is fed into an electric furnace or the like to remove vaporized water-resistant particulate organic matter and organic binder outside the furnace and to prevent oxygen-deficient state.
It is preferable because the pores are formed sufficiently and uniformly. Degreasing is performed, for example, by drying the dried molded body from room temperature to 300 to 40.
The temperature may be gradually raised to 0 ° C. and maintained at this temperature for 10 to 50 hours. The firing temperature is 400 to 1500 ° C, preferably 500 to 1000 ° C, and the firing time is 10 to 50 hours, preferably 20 to 30 hours. It is preferable that the firing temperature and the firing time be within the above ranges because the strength of the porous molded body is high and the cost is low.

The hollow cylindrical oil holding member 2 manufactured as described above can hold a large amount of the silicon oil 6 in the pore group. Further, flanges 14 are provided at both ends in a liquid-tight manner. The shaft 15 is mounted in a liquid-tight manner to form a hollow portion 5 having a cylindrical tank shape. Therefore, the hollow portion 5 is surrounded by the cylindrical oil holding member 2, the flanges 14 provided at both ends thereof, and the shaft 15 mounted on both the flanges 14, and is formed in a cylindrical tank shape. The thickness of the cylindrical oil holding member 2 is not particularly limited, but may be appropriately determined, for example, in the range of 1 to 10 mm. If the thickness of the cylindrical oil holding member 2 is too large, the volume of the hollow portion 5 becomes small, and the utilization rate of the release oil decreases. On the other hand, the cylindrical oil holding member 2
If the thickness is too small, the oil holding capacity is reduced, and oil leakage easily occurs as in the case of a conventional metal perforated pipe.

The flange 14 is provided with a pressure relief valve 17. The pressure relief valve 17 has a diameter of 3 to 6, for example.
A silicon rubber sheet member having a thickness of 0.3 to 2.0 mm, a hardness of 10 to 80, and a simple structure in which a cross-shaped notch passing through the center thereof is formed to penetrate the front and back surfaces can be used. Since the pressure relief valve 17 is provided between the hollow portion 5 and the outside air, the silicone oil 6 in the hollow portion 5
Is consumed, an air space 22 shown in FIG. When the pressure increases due to the expansion of the air layer 22 due to the heat, the pressure release valve 17
Is opened, and the pressure rise in the hollow portion 5 is reduced. Normally, the pressure release valve 17 is appropriately determined such as the diameter, thickness, and hardness of the silicon rubber sheet, and the pressure in the hollow is 1 to 30 gauge pressure.
It should be opened when it becomes kPa.

On the other hand, an oil coating layer 3 is formed on the outer periphery of an oil holding member 2 made of a cylindrical porous inorganic molded body. The oil application layer 3 includes an oil transfer layer 30 and an oil application amount control layer 31 provided thereon. The oil transfer layer 30 is made of heat-resistant fiber felt, is wound around the outer periphery of the oil holding member 2, absorbs the release oil from the oil holding member 2, and serves to supply the release oil to the oil application control layer 31. I am carrying it. The heat-resistant fiber felt here has a thickness of 1 to 3 mm and a density of 100 to 800 kg / m ^3.
Is used, but there is no particular limitation. As the release oil, a low-viscosity silicone oil of usually 50 to 300 cSt (25 ° C.) is used.

The oil application amount control layer 31 is not particularly limited as long as it has an air permeability of 10 to 2000 seconds / 100 cc and allows the passage of silicone oil. In the oil application amount control layer 31 of this embodiment, a stretched polytetrafluoroethylene (PTFE) porous film (hereinafter referred to as PTFE) is used.
(Referred to as a porous membrane). The oil application amount control layer 31 is bonded to the oil transfer layer 30 formed on the outer periphery of the oil holding member 2 with a mixture of an adhesive and silicone oil, and the mixture is sufficiently mixed. It is important that they are dispersed with each other. The mixture is applied to the entire outer peripheral surface of the oil transfer layer 30, and the oil application amount control layer 31 is wound around and adhered to the applied surface. That is, the entire surface of the oil application amount control layer 31 that is in contact with the entire outer periphery of the oil transfer layer 30 is bonded with the mixture. This adhesive is not particularly limited as long as it can bond the oil transfer layer 30 and the oil application amount control layer 31 in the state where the adhesive coexists with the silicone oil. In this embodiment, a silicone varnish is employed as an adhesive, and the mixing ratio of the silicone varnish (SW) and the silicone oil (SO) is 99: 1 to 20:80.
(SW: SO = 99: 1 to 20:80).

Next, a method of using the oil application roller 1 having the above configuration will be described. First, the plug of the release oil supply port of the oil application roller 1 is removed, and the silicone oil 6 is removed.
Is injected into the hollow portion 5 from the release oil supply port, and is plugged. Silicon oil 6 filled in this hollow part 5
When the oil application roller 1 is held in the oil holding member 2 once, the pressure in the hollow portion and the capillary force generated by the oil holding member are balanced, and the oil application roller 1 hardly leaks outside during transportation or storage. And this oil application roller 1
Are used in the fixing device 10. The oil application roller 1 is provided with a sufficient amount of silicone oil 6 from the hollow portion 5.
Can be supplied to the porous oil holding member 2, so that the adjustment width of the oil application amount can be widened, and the oil application layer 3 can evenly pass through the oil application layer 3, and can be applied to the peripheral surface of the heat fixing roll 11 that is in contact with the oil fixing layer 11. Silicon oil 6 can be applied. Therefore, in order to fix the toner 13 transferred to the surface 4 a of the recording paper 4, the toner 13 adheres to the heat fixing roll 11 even when the recording paper 4 is passed between the heat fixing roll 11 and the pressure roll 12. There is nothing. When the silicone oil 6 is continuously applied to the heat fixing roll 11, the silicone oil 6 in the hollow portion 5 becomes a state shown in FIG. When the temperature of the oil application roller 1 increases while the fixing device 10 is in use, the air layer 22 and the silicone oil 6 thermally expand, and the pressure in the hollow portion 5 increases. In this case, the pressure is released by the pressure release valve 17, and adverse effects such as excessive oil transfer and oil leakage can be prevented.

[0035]

EXAMPLES Next, the present invention will be described more specifically with reference to examples, but this is merely an example and does not limit the present invention.

EXAMPLES AND COMPARATIVE EXAMPLES First, in order to obtain porous ceramics having various porosity, total porosity and air permeability as shown in Table 2, a raw material mixture as shown in Table 1 was kneaded in a predetermined amount. To obtain a kneaded material. Next, the kneaded product was formed into a cylindrical shape by an extrusion molding method, and then dried at 105 ° C. for 10 hours to obtain a cured molded product. Further, the molded body is cooled to 400 ° C. at 5 ° C./h.
The temperature was raised to degrease in r., then baked at 800 ° C for 5 hours, and the methylcellulose and polyethylene powder were vaporized and disappeared. A porous ceramic having a shape was obtained.
During degreasing and firing, fresh air was constantly fed into the furnace to facilitate removal of methylcellulose and polyethylene powder, and to keep these vapors from stagnating in the furnace. Next, around the porous ceramic, a thickness of 2.
8 mm, basis weight 525 g / cm ² , space between fibers is about 100 μm
Nomex felt manufactured by Nippon Felt Kogyo Co., Ltd., and a PTF having a thickness of 30 μm, a porosity of 60%, and a maximum pore diameter of 10 μm is wrapped around the surface of the felt.
The E porous film was bonded with a mixture of silicone oil and silicone varnish to obtain an oil application roller. About the obtained oil application roller, the porosity, the total porosity, the air permeability, the pressure difference between the atmosphere and the hollow part, and the dimethyl silicone oil (KF-96 manufactured by Shin-Etsu Chemical Co., Ltd., oil viscosity 1)
The release oil retention in the felt using 00 cSt (25 ° C.) was measured. Table 2 shows the results.

[0037]

[Table 1]

[0038]

[Table 2]

* 1 Average particle size 400 μm * 2 Pores occupying porous ceramics (average particle size 400 μm)
m)). * 3 Indicates the oil retention rate in felt.

As can be seen from Table 2, when silicone oil having a viscosity of 100 cSt at 25 ° C. was used as the release oil, if the ratio of the pores having an average diameter of 400 μm was too small, the air permeability became large and the release of the felt was increased. It can be seen that the retention of the mold oil is low. In addition, it can be seen that when the ratio of pores having an average diameter of 400 μm is within an appropriate range and the air permeability is within a predetermined range, the release oil is smoothly transferred to the felt. It has been previously obtained by experiments that smooth oil application is possible if the oil retention rate in the felt is about 20% or more.

[0041]

According to the present invention (1), the utilization rate of the release oil is reduced by about 7 to 50% of the cylindrical oil holding member.
It can be improved to 5%. When the release oil is held, the hollow part is in a decompressed state, which balances with the capillary force and does not cause oil leakage even during transportation or storage, and it has a small and simple structure when used. It is possible to apply evenly while controlling the amount of release oil supplied to the fixing roller. According to the present invention (2), the release oil is applied to the fixing roll by the release of the release oil held in the pores of a specific size by capillary force, passing through the fine-diameter gap, and forming a felt coating layer. It is performed by being supplied to. For this reason, the supply amount of the release oil to the oil coating layer can be adjusted by the porosity, and if the porosity is in the above range, the release oil supplied to the fixing roller can be applied uniformly while controlling the amount of the release oil. According to the present invention (3), when the release oil is filled in the oil holding member, the release oil is held in the pores through the fine diameter gap of the oil holding member. Part of the air is also drawn in, reducing the pressure in the hollow part. On the other hand, the release oil held in the pores moves to the felt, which is the oil application layer, through the microscopic voids due to the capillary force. When the degree of pressure reduction is within the above range, oil leakage does not occur even during transportation or storage in balance with the capillary force. The balance between the degree of decompression of this hollow part and the capillary force is kept the same during use,
The application amount of the release oil can be supplied stably without unevenness. According to the present invention (4), the amount of the release oil supplied to the fixing roller can be further uniformly controlled while controlling the amount.

[Brief description of the drawings]

FIG. 1 is a side view showing an installation state of an oil application roller according to an embodiment of the present invention in a fixing device.

FIG. 2 is an axial sectional view of an oil application roller according to the embodiment of the present invention.

FIG. 3 is a radial sectional view of the oil application roller according to the embodiment of the present invention.

FIG. 4 is a cross-sectional view in a radial direction showing a use state of the oil application roller according to the embodiment of the present invention.

FIG. 5 is a schematic diagram of an apparatus for measuring a gas flow resistivity.

FIG. 6 is an axial sectional view showing a conventional example.

FIG. 7 is an axial sectional view showing a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1, a, h Oil application roller 2, b Oil holding member 3 Oil application layer 4 Recording paper 4a Surface 5 Hollow part 6 Silicon oil (release oil) 10 Fixing device 11 Heating fixing roll 12 Pressure roll 13 Toner 14 Flange 15 Shaft 17 Pressure release valve 22, i Air layer 30, c Oil transition layer 31, d Oil application amount control layer 40 Permeability measuring device 41 Differential pressure gauge 42 Flow meter 43 Compressor 44 Cylindrical pressure vessel 45 Sample e Hole f Oil Holding tank g Release oil

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Seiki Ono 1-1-26 Shiba-Daimon, Minato-ku, Tokyo Inside Nichias Corporation (72) Inventor Tsuyoshi Kuboyama 1-2-1 Shintoda, Hamamatsu-shi, Shizuoka Nichias Inside Hamamatsu Laboratory Co., Ltd. (72) Inventor Munehiko Fukase 1-8-1 Shintoda, Hamamatsu-shi, Shizuoka Nichias F-term in Hamamatsu Research Laboratories Co., Ltd. 2H033 AA09 AA21 AA32 BA42 BA43 3J103 AA02 AA14 AA79 AA85 GA57 GA58 HA03 HA18 4F040 AA05 AB08 BA14 CB02 CB28 CB40

Claims (4)

[Claims] An oil application roller provided with an oil application layer on an outer periphery of an oil holding member formed of a hollow cylindrical porous molded body and supplying release oil held by the oil holding member to a fixing roll. , The porous molded body,
It is made of an inorganic material having fine pores and pores inside,
At least a part of the fine pores communicates with the surface of the porous molded body and the pores, and the pores at least partially communicate with the surface of the porous molded body through the fine pores, and the air is ventilated. An oil application roller having a resistivity of 100 to 6000 Pa · s / m ² . 2. An oil application roller comprising: an oil application layer provided on an outer periphery of an oil holding member formed of a hollow cylindrical porous molded body; and supplying release oil held by the oil holding member to a fixing roll. , The porous molded body,
It is made of an inorganic material having fine pores and pores inside,
The fine pores at least partially communicate with the surface of the porous molded body and the pores, and at least 40% of the total fine pore volume is composed of pores having a diameter of 30 to 200 μm, and the pores are at least partially formed. Communicates with the surface of the porous compact through the fine pores, and has an average pore diameter of 200
An oil application roller, wherein the total volume of the pores is 5 to 30% in the porous molded body. 3. An oil application roller provided with an oil application layer on an outer periphery of an oil holding member formed of a hollow cylindrical porous molded body and supplying release oil held by the oil holding member to a fixing roll. , The porous molded body,
It is made of an inorganic material having fine pores and pores inside,
At least a part of the fine pores communicates with the surface of the porous molded body and the pores, and the pores at least partially communicate with the surface of the porous molded body through the fine pores. The pressure (P ₁ ) and the atmospheric pressure (P ₂ ) of the gas phase of the hollow part are maintained while the release oil is held in the hollow part.
Wherein the pressure difference (P ₁ -P ₂ ) is in the range of -0.05 to -2.0 KPa. 4. The oil application layer comprises an oil transfer layer and an oil application amount control layer provided thereon, and both layers are adhered by a mixture of an adhesive and silicone oil. The oil application roller according to any one of claims 1 to 3.