JP2003084585A - Fixing sleeve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the durability by suppressing the deterioration or wear of a metal layer in a fixing sleeve provide with the metal layer. SOLUTION: In the fixing sleeve 10 in which an elastic layer 13 and a releasing layer 14 are successively formed on the outside of a core metal layer 11, and inner surface and the outer surface of the metal layer 11 are covered by heat-resistant protective layers 12a and 12b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing sleeve used in a film fixing type fixing device.

[0002]

2. Description of the Related Art In copying / printing equipment such as electrophotographic copying machines, facsimiles and laser beam printers, toner made of heat-meltable resin is used for image formation processes such as electrophotography, electrostatic recording and magnetic recording. A heat fixing method in which an image is formed on recording paper and is fixed by heat is generally adopted.

As a fixing device used in such a heat fixing method, conventionally, a recording paper on which a toner image is formed is fed between two rollers, a heat fixing roller having a built-in heater and a pressure roller, for fixing. Although a heat roller system was generally used, in recent years, instead of the heat fixing roller, a film-shaped seamless sleeve made of a heat-resistant resin such as polyimide or polyamide-imide, or the outer peripheral surface thereof is coated with a fluororesin or the like. A film fixing method using a composite sleeve has been developed and is being widely used.

The fixing device based on this film fixing system is
A heater is placed inside the film-shaped sleeve, the sleeve is pressed against the heater, and a pressure roller is pressed outside the portion pressed against the heater. The recording paper on which the toner image is formed is passed between the pressure roller and the recording paper, and the recording paper is heated via the heat-resistant sleeve to thermally fix the unfixed toner image on the recording paper.

In this method, since the heat capacity of the sleeve made of a thin film is small, the heat fixing can be performed almost at the same time when the power is turned on, and the energy required for heating can be reduced.

Further, recently, a fixing system has been developed in which a film sleeve made of metal such as iron, aluminum or nickel is used in place of the film sleeve made of heat resistant resin as described above. Among them, the induction heating method in which a magnetic metal layer such as iron or nickel is self-heated by an eddy current caused by electromagnetic induction is to obtain a uniform temperature distribution in the nip part (transfer part) due to the thermal conductivity of the metal layer. Since the unevenness of the image and the unevenness of fixing are less likely to occur due to the heat generation, and the sleeve itself is a heating element, the heat transfer loss is small, and the heating can be performed more quickly and efficiently.

[0007]

However, the fixing method using the sleeve having such a metal layer has a problem that the life of the fixing sleeve is short because the metal layer is weak against repeated stress such as bending. It was Particularly, in the induction heating method, the magnetic metal layer is easily worn by contact with an exciting coil that generates a magnetic flux, so that the life of the fixing sleeve is further shortened, and in addition, the thickness of the magnetic metal layer is reduced by the wear. Therefore, there is a problem in that the Joule heat is generated unevenly and uneven fixing of the image occurs.

The present invention has been made in order to solve such a problem, and it is possible to suppress embrittlement due to repeated bending of a metal layer and abrasion due to contact with an exciting coil.
It is an object of the present invention to provide a fixing sleeve having excellent life characteristics that can provide stable fixing performance for a long period of time.

[0009]

In order to solve the above problems, the fixing sleeve of the present invention is a fixing sleeve in which an elastic layer and a release layer are sequentially formed on the outer side of a metal layer, At least one of the inner surface and the outer surface of the metal layer is covered with a heat resistant protective layer.

In the fixing sleeve having the above-mentioned structure, at least one of the inner surface and the outer surface of the metal layer is covered with the heat-resistant protective layer, so that the metal layer becomes brittle due to repeated bending or comes into contact with an exciting coil or the like. Wear is suppressed and durability is improved.

In the present invention, the heat resistant protective layer is preferably coated on both inner and outer surfaces of the metal layer. Thereby, the durability can be further improved.

The heat-resistant protective layer has a thickness of 5 μm to 40 μm.
It is preferably m. When the thickness of the heat resistant protective layer is less than 5 μm, the effect of protecting the metal layer is small and the durability cannot be sufficiently improved. On the other hand, if the thickness exceeds 40 μm, the effect does not change so much, and the flexibility may decrease.

The heat-resistant protective layer is preferably made of a heat-resistant resin, and in particular, it is formed by applying a heat-resistant resin varnish on a predetermined surface of the metal layer, drying it, and then firing it. Are more preferable from the viewpoint of durability and the like.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a fixing sleeve according to an embodiment of the present invention. As shown in FIG. 1, the fixing sleeve 10 of this embodiment includes a metal layer 11 and a heat-resistant protective layer 12 that covers the inner surface and the outer surface of the metal layer 11.
a, 12b, and an elastic body layer 13 and a release layer 14 which are sequentially formed on the outer circumference of these.

The metal layer 11 is made of aluminum, iron, stainless steel, nickel, cobalt, alloys thereof, or the like and has a thickness of 20 μm to 100 μm, preferably 25 μm to 80 μm.
A thin metal sleeve of μm is used. 20 μm thickness
If the thickness is thinner, the strength will be reduced, and if the thickness exceeds 100 μm, the heat capacity will be large and the time required to raise the temperature will be long, and it will be more brittle against repeated bending and the like, and sufficient durability will be obtained. There is a risk that you will not be able to. A sleeve made of a magnetic metal such as iron, ferritic stainless steel, nickel, or cobalt is used for the purpose of application of a method in which an eddy current is generated in a metal layer by electromagnetic induction to cause self-heating and heat fixing.

The heat-resistant protective layers 12a and 12b coated on the inner and outer surfaces of the metal layer 11 are mainly embrittled by repeated bending of the metal layer 11 under heat and pressure, or cracked, or It has a function of preventing the metal layer 11 from being worn due to contact with the exciting coil.

The heat-resistant protective layers 12a and 12b are made of thermosetting polyimide resin, polyamideimide resin, polybenzimidazole resin, polybenzoxazole resin, polyphenylene sulfide resin, polyetheretherketone resin, polyethersulfone resin, polyetherimide. It is preferable to use a resin such as a resin having excellent heat resistance and moderate elasticity.

The layer thickness of each of the heat-resistant protective layers 12a and 12b is preferably in the range of 5 μm to 40 μm, and more preferably in the range of 7 μm to 30 μm.
If the layer thickness is less than 5 μm, the effect of protecting the metal layer 11 is small and the durability cannot be sufficiently improved. If the layer thickness exceeds 40 μm, it is economically disadvantageous.

In the present invention, although the protective effect on the metal layer 11 is lowered, either the inner surface or the outer surface of the metal layer 11 may be coated with the heat resistant protective layer as described above. However, in the case of an application of a system in which an eddy current is generated in the metal layer by electromagnetic induction to generate heat and self-heats, it is preferable to form the heat-resistant protective layer at least inside the metal layer 11 with the resin described above. By covering the inside of the metal layer 11 with a resin having a thermal conductivity several steps lower than that of metal, heat dissipation to the inside can be reduced and energy efficiency can be increased.

The elastic layer 13 is made of rubber having excellent heat resistance such as silicone rubber, and the releasing layer 14 is made of resin having excellent releasing property such as fluororesin. To be done. Fluorine layer resin includes PTFE (polytetrafluoroethylene), PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer),
Examples include FEP (tetrafluoroethylene / hexafluoropropylene copolymer), PVdF (polyvinylidene fluoride), ETFE (ethylene / tetrafluoroethylene copolymer) and the like.

The thickness of the elastic layer 13 and the release layer 14 is not particularly limited, but the elastic layer 13 is not limited.
Is usually 10 μm to 1000 μm, preferably 50 μm to 800
and the release layer 14 is usually 10 μm.
˜100 μm, preferably 15 μm to 70 μm.
When the thickness of the elastic layer 13 is less than 10 μm, the uniformity of fixing property is deteriorated, and when the thickness exceeds 1000 mm, the thermal response is deteriorated. Further, if the thickness of the release layer 14 is less than 10 μm, the abrasion resistance is reduced and the life of the fixing sleeve is shortened. On the other hand, if the thickness exceeds 100 mm, the thermal response will decrease, and
Flexibility is also reduced.

In such fixing sleeve 10, the inner and outer surfaces of the metal layer 11 are heat-resistant protective layers 12a,
Since it is covered with 12b, embrittlement and wear of the metal layer 11 due to repeated bending and contact with the exciting coil are suppressed, durability is improved, and stable fixing performance can be provided for a long period of time.

The fixing sleeve 10 can be manufactured, for example, as follows. First, a thin metal sleeve made of metal such as iron or aluminum is prepared, and a varnish containing a heat-resistant resin or a precursor thereof in a solvent is applied to the inner surface and the outer surface of the sleeve, and heat-fired to form a heat-resistant protective layer. 12a and 12b are formed.

Examples of the varnish include 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-diaminodiphenyl ether, 4,3 when the heat resistant resin is a polyimide resin.
Aromatic diamines such as 4'-diaminodiphenyl ether and p-phenylenediamine, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, benzophenone-3,3', 4 A polyimide precursor obtained by reacting an aromatic tetracarboxylic acid such as 4,4'-tetracarboxylic dianhydride with an organic polar solvent such as N-methyl-2-pyrrolidone (NMP), dimethylacetamide or dimethylformamide The one prepared by dissolving the body in a solvent is used.

On the other hand, as shown in FIG. 2, a sleeve 21 made of a releasing resin such as a fluororesin sleeve is inserted inside the cylindrical mold 20 held upright, and both ends of the sleeve 21 are placed on the cylindrical mold 20. Bend and fix.

Then, the metal sleeve 22 having the heat resistant protective layers 12a and 12b formed on the inner and outer surfaces thereof is inserted into the releasable resin sleeve 21 and coaxially held.
A cylindrical or cylindrical core body 23 is previously inserted into the metal sleeve 22 as a support. The core body 23 is made of a hard material such as a metal or ceramics such as aluminum or stainless steel, or a cylindrical body or a cylindrical body. The outer peripheral surface of the cylindrical body or the cylindrical body is released by a fluorine resin sleeve or the like. Those provided with a volatile resin layer are used. In FIG. 2, reference numerals 24 and 25 denote plugs for closing the inside of the cylindrical mold 20 and for coaxially holding the metal sleeve 22 inside the cylindrical mold 20.

After that, a liquid elastic material such as liquid thermosetting (LTV) silicone rubber is introduced into the gap between the releasable resin sleeve 21 and the heat-resistant protective layer 12b through a material injection hole 26 provided in the plug 24. 27 is injected and the excess is plugged 25
After slightly overflowing from the escape hole 28 provided in
The elastic layer 13 is formed by heating and curing.

As a result, the metal layer 11 as shown in FIG.
A fixing sleeve 10 is obtained in which the inner and outer surfaces of the are covered with heat-resistant protective layers 12a and 12b, and an elastic layer 13 and a release layer 14 composed of a releasable resin sleeve 21 are sequentially formed thereon. be able to. It is desirable that the inner surface of the releasable resin sleeve 21 be subjected to etching and / or primer treatment in advance in order to enhance the adhesiveness.

[0029]

EXAMPLES The present invention will be described in more detail below with reference to examples.

Example 1 Stainless steel (SUS with an inner diameter of 50 mm, a length of 250 mm and a thickness of 0.05 mm)
A seamless sleeve made of 304) was dipped in a 5% polyimide precursor solution (solvent NMP), pulled up, and then left for 20 minutes. Put this in the heating furnace, from room temperature to 320 ℃
The temperature was raised over 1.5 hours, the temperature was maintained as it was for 30 minutes, and then the temperature was cooled to room temperature to form a polyimide resin layer having a thickness of 10 μm on each of the inner surface and the outer surface of the seamless sleeve.

Next, in the hollow portion of the polyimide resin-coated stainless steel sleeve, a PTFE layer is provided on the outer surface of an iron cylindrical tube as a support, and the outer diameter is substantially the same as the inner diameter of the polyimide resin-coated stainless steel sleeve. Inserted the core body.

On the other hand, as shown in FIG. 2, the inner surface of a cylindrical mold 20 having an inner diameter of 51.3 mm was etched, primer # 101 (trade name of Shin-Etsu Chemical Co., Ltd.) was applied and dried, and the outer diameter was 48.8 mm. , Length 350mm, thickness 0.025mm PFA sleeve 2
1 was inserted and both ends were bent and fixed on the cylindrical mold 20.

Then, the polyimide resin-coated stainless steel sleeve 22 having the core 23 inserted therein is inserted into the cylindrical mold 20 to which the PFA sleeve 21 is fixed,
A stopper 24 is provided on the upper and lower portions of the cylindrical mold 20, respectively.
After fitting 25 and holding them coaxially, an LTV silicone rubber (product name G922 manufactured by GE Toshiba Silicone Co., Ltd.) having a hardness (JIS A) of 20 degrees after curing is attached to a polyimide resin-coated stainless steel sleeve 22 and a PFA sleeve. 21 was injected and injected into the gap. After the injection, the temperature was raised to 150 ° C. and heated for 1 hour to cure the silicone rubber. After removing the mold, the mold was further heat-treated at 200 ° C. for 4 hours, and cut at both ends by 5 mm to obtain a fixing sleeve having an outer diameter of 51.28 mm, a length of 240 mm and a silicone rubber layer thickness of 0.6 mm.

The fixing sleeve thus obtained was incorporated into a heat fixing section of an electrophotographic copying machine, and a continuous paper feeding test (paper feeding speed: A4 paper, 30 sheets / minute) was carried out at a set surface temperature of 190 ° C. No problems occurred even with the passage of 10,000 sheets, and it had good durability.

Comparative Example 1 An outer diameter of 51.28 mm and a length of 2 were obtained in the same manner as in Example 1 except that the step of providing a polyimide resin layer on the inner and outer surfaces of a seamless sleeve made of stainless steel (SUS 304) was omitted.
A fixing sleeve having a thickness of 40 mm and a silicone rubber layer of 0.6 mm was manufactured.

The obtained fixing sleeve was subjected to the continuous paper feeding test in the same manner as in Example 1. As a result, a crack was generated at the end of the stainless steel sleeve after 60,000 sheets of paper were passed, and the subsequent passage of paper was difficult. Became.

Example 2 Inner diameter 50 mm, length 350 mm, thickness 0.05 m manufactured by electroforming method
A nickel sleeve of m was dipped in a 5% polyimide precursor solution (solvent NMP), pulled up, and then left for 20 minutes. This is placed in a heating furnace, heated from room temperature to 320 ° C over 1.5 hours, held for 30 minutes, cooled to room temperature, and then applied to the inner and outer surfaces of the seamless sleeve, respectively.
A 10 μm thick polyimide resin layer was formed.

Next, a fluorine resin (PTFE) layer is provided on the outer surface of an iron cylindrical tube as a support in the hollow portion of the polyimide resin-coated nickel sleeve, and the outer diameter is substantially the same as the inner diameter of the polyimide resin-coated nickel sleeve. A core body having the same diameter was inserted.

On the other hand, as shown in FIG. 2, the inner surface of a cylindrical mold 20 having an inner diameter of 51.3 mm was etched, primer # 101 (trade name of Shin-Etsu Chemical Co., Ltd.) was applied and dried, and the outer diameter was 48.8 mm. , Length 350mm, thickness 0.025mm PFA sleeve 2
1 was inserted and both ends were bent and fixed on the cylindrical mold 20.

Then, the polyimide resin-coated nickel sleeve 22 having the core 23 inserted therein is inserted into the cylindrical mold 20 to which the PFA sleeve 21 is fixed, and the upper and lower parts of the cylindrical mold 20 are inserted. 24 and 25 respectively
After mating and holding them coaxially, the hardness after hardening (JIS
A) LTV silicone rubber having a degree of 20 degrees (trade name G922 manufactured by GE Toshiba Silicones Co., Ltd.) was injected into the gap between the polyimide resin-coated nickel sleeve 22 and the PFA sleeve 21. After the injection, the temperature was raised to 150 ° C. and heated for 1 hour to cure the silicone rubber. After demolding, 4 more at 200 ℃
Heat treatment for an hour, cut 10 mm each on both ends, outer diameter 51.28 m
A fixing sleeve having a length of m, a length of 330 mm, and a silicone rubber layer having a thickness of 0.6 mm was obtained.

The fixing sleeve thus obtained was incorporated into the heat fixing section of an induction heating type electrophotographic copying machine, and a continuous paper feeding test (paper feeding speed: A4 paper, 30 sheets / minute) was conducted at a set surface temperature of 190 ° C. As a result, there was no problem even after passing 300,000 sheets, and it had good durability.

Comparative Example 2 The outer diameter was 51.28 mm, the length was 330 mm, and the thickness of the silicone rubber layer was 0.2 mm in the same manner as in Example 2 except that the step of providing the polyimide resin layer on the inner surface and the outer surface of the nickel sleeve was omitted.
A 6 mm fixing sleeve was manufactured.

The obtained fixing sleeve was subjected to the continuous paper feeding test in the same manner as in Example 2. When 120,000 sheets of paper were passed, a crack was generated at the end of the nickel sleeve, and subsequent passage of paper was difficult. became.

It is needless to say that the present invention is not limited to the above-mentioned embodiment, and can be modified and carried out without departing from the spirit of the invention.

[0045]

As is apparent from the above embodiments, according to the present invention, embrittlement and abrasion of the metal layer due to repeated bending and contact with an exciting coil are suppressed, and stable fixing performance can be obtained for a long period of time. A fixing sleeve having excellent life characteristics can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view showing a fixing sleeve according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a manufacturing process of the fixing sleeve of FIG.

[Explanation of symbols]

10 ... Fixing sleeve 11 ... Metal layer 12a, 12b ......... Heat-resistant protective layer 13 ... Elastic layer 14 ... Release layer

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takayuki Yamazaki             2-1-1 Oda Sakae, Kawasaki-ku, Kawasaki-shi, Kanagawa             No. Showa Densen Denki Co., Ltd. (72) Inventor Yasuo Kawashima             2-1-1 Oda Sakae, Kawasaki-ku, Kawasaki-shi, Kanagawa             No. Showa Densen Denki Co., Ltd. F term (reference) 2H033 AA26 BA11 BA12 BA25 BE03                       BE06

Claims (5)

[Claims] 1. A fixing sleeve in which an elastic layer and a release layer are sequentially formed on the outside of a metal layer, wherein the metal layer has at least one of an inner surface and an outer surface covered with a heat-resistant protective layer. A fixing sleeve characterized in that 2. The fixing sleeve according to claim 1, wherein the heat-resistant protective layer is coated on both inner and outer surfaces of the metal layer. 3. The heat-resistant protective layer has a thickness of 5 μm to 40 μm.
The fixing sleeve according to claim 1, wherein the fixing sleeve is m. 4. The fixing sleeve according to claim 1, wherein the heat resistant protective layer is made of a heat resistant resin. 5. The heat resistant protective layer is formed by applying a heat resistant resin varnish on a predetermined surface of the metal layer, drying the varnish, and then firing the varnish. The fixing sleeve described.