Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Reexamination Certificate
2001-05-24
2004-06-22
Wu, David W. (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
C524S421000, C524S545000, C524S546000, C428S421000, C430S105000, C427S226000
Reexamination Certificate
active
06753371
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a fluorine rubber composition used in an image picture forming apparatus, a fixing member, a fixing device, a fixing method, and a method of manufacturing the fixing device.
BACKGROUND OF THE INVENTION
In an image picture forming apparatus, a toner transferred onto a recording material such as paper or the like is fixed by a fixing device installed in the apparatus.
FIG. 6
is a sectional view of a conventional fixing device. The fixing device which serves to fix a toner
13
transferred onto a recording material
12
comprises a fixing roller
201
being a fixing member, a press roller
102
opposing to the fixing roller
201
, and a web
104
impregnated with silicone oil as a lubricant to prevent sticking of toner T to surface layer
203
of the fixing roller
201
. The fixing roller
201
and the press roller
102
are formed by coating a core bar
105
with an elastic body
106
. A heater
107
as a heat source is disposed in the core bar
105
of the fixing roller
201
.
Recording material
12
such as paper or the like with a picture image formed thereon by transferring the toner
13
is caught between the fixing roller
201
and the press roller
102
, and is heated and pressed, then the toner
13
is fixed on the recording material
12
.
However, the toner
13
increases in viscosity due to the heat. Accordingly, as shown in the partly enlarged view of
FIG. 3
showing a state of picture image fixation in a conventional fixing device, a part of the toner
13
on the recording material
12
adheres to the surface of the fixing roller
201
. As a result, when the next recording material
12
advances toward the fixing roller
201
heated, the toner
13
, increasing in viscosity and adhering to the fixing roller
201
, is partially transferred onto the next recording material
12
. This process is generally called offset, and frequent generation of offset means the termination of the life of the fixing device.
In order to prevent generation of such offset, in the prior art, the toner is fixed by heat and pressure of the fixing roller
201
and the press roller
102
while applying a lubricant such as silicone oil to the fixing roller
201
. There are some different methods of lubricant application to the fixing roller
201
. For examples, as shown in
FIG. 6
, a lubricant is applied to the fixing roller
201
by contacting the web
104
with the fixing roller
201
. The web
104
is pressed against the fixing roller
201
by a web pressing roller
108
and is taken up onto a web take-up roller
110
from a web feed roller
109
at a predetermined speed.
However, in a conventional fixing device, the surface layer
203
of the fixing roller
201
is formed of silicone rubber, fluorine rubber or the like. Since the fixing roller
201
is heated, the surface layer
203
of the fixing roller
201
is deteriorated due to the heat. Further, in use of the fixing roller
201
for a long period of time, the surface layer
203
becomes worn and scratched due to sticking of paper and dust. In case the surface layer
203
is worn or scratched, the toner
13
will stick to the surface layer
203
of the fixing roller
201
despite that the surface layer
203
is coated with a lubricant. That is, there are not a few chances of generation of offset even when the surface layer
203
is coated with a lubricant.
A fixing device capable of preventing such offset is disclosed in Japanese Laid-Open Patent No. 4-319980. The fixing device disclosed in Japanese Laid-Open Patent No. 4-319980 comprises a fixing roller and a roller polishing means to polish the fixing roller surface. The fixing roller used is a single-layer roller formed of methyl or methylvinyl type silicone rubber, and the silicone oil used is methylphenyl type silicone oil.
In such fixing roller, the fixing roller surface is always refreshed since the fixing roller surface is polished by the roller polishing means. As a result, generation of offset can be prevented. Also, since a single-layer roller formed of silicone rubber is employed, polishing the fixing roller surface does not cause the under layer material to be exposed, thereby improving the durability.
However, in such prior art fixing device, the optimum conditions for roller polishing vary with various factors such as grain sizes of polishing material, grain shapes, its contents in silicone oil, abutment pressures to the fixing roller of cleaning web as a roller polishing means, abutment areas, fiber density of web, and material quality of roller rubbers. Accordingly, it is difficult to find and maintain optimum values in relation to a number of these factors. Further, as the fixing roller surface is polished, the roller will be reduced in diameter through use for a long period of time. Consequently, the above-mentioned factors at their optimum values are influenced, gradually going wrong.
The present invention is intended to improve the durability of the fixing member, preventing generation of offset reliably for a long period of time by lessening the amount of toner sticking to the fixing member surface without polishing the fixing member surface of a roller or the like.
SUMMARY OF THE INVENTION
A fluorine rubber composition of the present invention, used for the surface layer material of a fixing member to fix a toner transferred onto a recording material, comprises:
(a) fluorine rubber having a polymerization degree based on vinylidene fluoride; and
(b) at least one selected from the group consisting of a reinforcing agent, an antacid, a vulcanizing agent, a vulcanization accelerator, a spherical filler, and an organic solvent.
A fixing member of the present invention for fixing a toner transferred onto a recording material comprises:
a base material and
a surface layer material disposed on the base material,
wherein the surface layer material contains fluorine rubber having a polymerization degree based on vinylidene fluoride.
A fixing device of the present invention for fixing a toner transferred onto the surface of a recording material comprises:
a fixing roller;
a press roller disposed opposing the fixing roller; and
a web to apply a lubricant to the surface of the fixing roller,
wherein the fixing roller comprises a base material and a surface layer material disposed on the surface of the base material;
the surface layer material contains fluorine rubber having a polymerization degree based on vinylidene fluoride; and
a recording material having the toner transferred thereon passes between the fixing roller and the press roller while being pressed by the fixing roller and the press roller so that the surface layer material comes in contact with the toner, and thereby, the toner is fixed on the recording material.
A fixing method of the present invention comprises:
(a) a step of transferring a toner onto the surface of a recording material:
(b) a step of passing the recording material, having the toner transferred thereon, between a fixing roller and a press roller, under pressures applied by the fixing roller and the press roller,
wherein the fixing roller comprises a base material and a surface layer material disposed on the surface of the base material;
the recording material passes between the rollers in a manner such that the toner is positioned at the fixing roller side;
the surface layer material contains fluorine rubber having a polymerization degree based on vinylidene fluoride; and
(c) a step of fixing the toner, pressed by the fixing roller and the press roller, on the surface of the recording material.
A method of manufacturing a fixing device of the present invention for fixing a toner transferred onto the surface of a recording material comprises the steps of:
(a) manufacturing a fixing roller; and
(b) manufacturing a press roller,
wherein the step of manufacturing the fixing roller comprises the steps of:
(1) manufacturing a paint;
wherein the step of manufacturing the paint includes a step of mixing and dispersing fluorine rubber having a polymerization degree based on vinylidene fluoride,
Kama Hirofumi
Kiyomura Yoshihiro
Noda Hiroyuki
Hu Henry S.
Matsushita Electric - Industrial Co., Ltd.
McDermott & Will & Emery
Wu David W.
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