JP2003330294A - Fixing belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixing belt which is inexpensive and excellent in fixing property without having elongation or slipping even at high temperature and high pressure. <P>SOLUTION: In the fixing belt having a multilayer structure in the radial direction, a base layer (2) which suppresses elongation in the radial direction is formed in the layers. The inner layer portion (1) is made of a heat-resistant rubber elastic material and the outer layer portion (3) is made of a heat-resistant rubber elastic material or a heat-resistant resin. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic copying machine,
In image forming devices such as facsimiles and printers,
The present invention relates to a fixing belt used in a fixing unit that fixes a toner image transferred onto a transfer material such as transfer paper by heating.

[0002]

2. Description of the Related Art Conventionally, there is known a fixing belt in which a heat-resistant elastomer layer composed of a soft segment and a hard segment is formed on an outer peripheral surface of a cylindrical polyimide tube via an adhesive layer composed of a heat-resistant synthetic resin layer. ing.
(See Japanese Laid-Open Patent Publication No. 10-161448) However, the above fixing belt has a problem that it stretches at high temperature and high pressure. Further, this belt has a problem of poor fixing property due to poor cushioning property. Further, there is a problem that the cost of the product is increased because the polyimide resin is expensive and the productivity is poor because the manufacturing process is complicated. On the other hand, a belt in which the base material is made of metal, such as nickel electroforming, is also known, but the problem of fixing property described above has not been solved.

[0003]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a fixing belt which solves the above problems and realizes cost reduction.

[0004]

DISCLOSURE OF THE INVENTION The present inventors have arranged a heat-resistant rubber-like elastic body typified by inexpensive silicone rubber or fluororubber on the inner layer portion of a fixing belt to provide cushioning and gripping properties. As a result of paying attention to the fact that the concerned "elongation" is suppressed by the inorganic fiber typified by the glass fiber at the time of securing, the conventional problems have been solved all at once.

Thus, according to the present invention, in the thick portion,
A fixing belt is provided, in which a base material layer that suppresses at least radial expansion of the belt is arranged, and at least an inner layer surface of the belt is made of a heat-resistant rubber-like elastic body. .

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION An example of a cylindrical fixing belt having a glass fiber layer as a base material layer and a three-layered thick portion formed by arranging silicone rubber on inner and outer layers will be described below. Will be described with reference to. FIG. 1 is a longitudinal sectional view showing an example of the fixing belt of the present invention, in which (1) is an inner layer portion,
(2) is a base material layer that suppresses elongation of the belt in at least the diameter (circumferential) direction, and (3) is an outer layer portion. A feature of the present invention is that a base material layer (2) that suppresses at least radial extension of the fixing belt is disposed between the inner layer portion (1) and the outer layer portion (3), and at least The inner layer portion (1), and hence the inner peripheral surface of the belt, is composed of a heat-resistant rubber-like elastic body. By adopting such a configuration, a. The belt itself exhibits an improved grip (anti-slip capability) for the roller on which it is suspended, and b. Since the cushioning property is secured in the thickness direction, there is no concern of crushing the toner, and good fixing property can be obtained.
And c. The interposition of the base material layer ensures that the elongation of the rubber-like elastic body is suppressed even under high temperature and high pressure. As such a base material layer (2), an inorganic fiber layer such as glass fiber is preferable because it is stable and inexpensive. The glass fiber layer is provided with a horizontally wound layer appropriately vertically attached, and further provided in a seamless aggregate structure such as a braided layer, but from the viewpoint of productivity and cost, the effect of suppressing the horizontal winding and elongation is braided. Since the layer is superior, these structures may be appropriately used according to the required characteristics of the belt. In this case, the wire diameter of the glass fiber is 5 μm to 200 μm, and the thickness of the braid is 10 μm.
˜300 μm, and finally it is desirable to adjust the thickness of the glass fiber layer to a range of 5 μm to 300 μm. Further, it is more preferable to use a composite layer of the glass fiber layer and the heat resistant resin, because the effect of suppressing elongation is further emphasized. The heat resistant resin in this case is not particularly limited as long as it is generally called a heat resistant resin, but among them, a polyimide resin is preferably used. The composite layer is formed, for example, by impregnating the above-mentioned horizontal winding layer or braided layer with a polyimide varnish. In the present invention, examples of the heat-resistant rubber-like elastic body arranged in the inner layer portion (1) include silicone rubber and fluororubber, but from the viewpoint of cost, silicone rubber is more preferable. The thickness of the inner layer portion (1) is 10 μm to 300 when considering both grip performance and strength.
It is preferably in the range of μm. On the other hand, the outer layer part (3)
The above-mentioned heat-resistant resin or heat-resistant rubber-like elastic body is arranged in the. In this case, a fluororesin is preferably used when releasability from the toner is prioritized, a polyimide resin is preferably used when high heat resistance is particularly required, and a silicone rubber is preferably used when cost is important. . here,
Specific examples of the fluororesin include tetrafluoroethylene resin (PTFE), tetrafluoroethylene / perfluoroalkoxyethylene copolymer (PFA), tetrafluoroethylene / hexafluoropropylene copolymer (FEP) and the like. Among these, a tetrafluoroethylene / perfluoroalkoxyethylene copolymer (PFA) is particularly preferable in terms of mold releasability and flexibility.
Further, as the polyimide resin, "Treney # 3000" (trade name) manufactured by Toray Industries, Inc. and "SKY" manufactured by IS.T.
“BOND” (trademark) is also used as the silicone rubber as “RTV (X-201) manufactured by Shin-Etsu Chemical Co., Ltd.
8) ”and“ RTV (X32-1032) ”(both are trade names). The thickness of the outer layer portion (3) is 10 μm to 300 μm, considering both releasability and durability.
It is desirable to be in the range of. The total thickness of the fixing belt made of the above materials is 500 μm or less,
Desirably 50 μm to 300 μm, more desirably 5
It is 0 μm to 150 μm. If this thickness is too thin, the strength of the belt will be weakened, while if it is too thick, the thermal conductivity of the belt will be reduced. Next, a method for manufacturing the fixing belt of the present invention will be described with reference to an example. First, a liquid silicone rubber is coated on a tubular body (an aluminum cored bar coated with PFA resin) matching the required inner diameter of the belt. Next, the coated silicone rubber is heated and solidified to form the inner layer portion (1). A glass fiber is wound around the outer circumference and the circumferential direction of the inner layer portion (1) in a horizontal winding method to form a base material layer (2). Then, the liquid silicone rubber is coated again and then vulcanized and solidified to form the glass fiber base material layer (2) and the outer layer portion (3) impregnated and solidified with the silicone rubber. Finally, the fixing belt of the present invention is obtained by pulling out the multilayer structure from the tubular material. Further, in the above aspect, when the inner layer portion (1) may be made relatively thin, the glass fiber is loosely wound or braided so that a gap is formed between the inner layer portion (1) and the outer peripheral surface of the tubular body. The liquid silicone rubber may be coated thicker than the fiber layer with the glass fiber layer formed. At this time, the silicone rubber filling the gap becomes the inner layer portion (1), and the silicone rubber placed on the outer peripheral surface of the glass fiber layer becomes the outer layer portion (3).
These belts may be subjected to finishing treatment such as surface polishing, if necessary. In the above embodiment, an example in which one glass fiber layer is provided as the base material layer (2) that suppresses at least radial expansion of the fixing belt has been described. However, in order to further increase the elongation suppression effect, the base material layer (2) may have two or more layers.

Specific examples of the fixing belt of the present invention are shown below. In the manufacturing method described above, the inner layer portion (1) is a silicone rubber layer having a thickness of 100 μm and a width of 350 mm,
A base material layer (2) having a thickness of 100 μm to 110 μm, which is obtained by horizontally winding a glass fiber having a wire diameter of 10 μm in a single layer on the outer periphery thereof.
Was formed. Furthermore, the outer periphery of the base material layer (2) has a thickness of 1
Forming an outer layer (3) of silicone rubber of 00 μm,
A cylindrical fixing belt having a wall thickness of 200 μm and a width of 350 mm was prepared. When the adhesive force between the layers of the fixing belt thus produced was measured by a 180 ° peel test, all were 500 gf / cm, and sufficient adhesive force was obtained. Further, when this belt was used in an actual machine (copier), it was confirmed that the belt did not slip and the image fixing property was good due to the sufficient elasticity of the silicone rubber layer.

[0008]

According to the present invention, the heat-resistant rubber-like elastic body ensures improved grip and cushioning,
Since the problem of belt elongation, which is a concern with the adoption of the elastic body, has been solved by introducing a base material layer made of an inexpensive material called glass fiber, elongation does not occur even when used under high temperature and high pressure. In addition, an inexpensive fixing belt having excellent fixing properties without slippage is also provided. Moreover,
Since the fixing belt of the present invention has a simple structure, workability during manufacturing is significantly improved and productivity is also improved.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an example of a fixing belt of the present invention.

[Explanation of symbols]

1 Inner layer of fixing belt 2 Base material layer that suppresses elongation of the fixing belt 3 Outer layer of fixing belt

Continued front page    F term (reference) 2H033 AA13 AA21 BA11 BA12 BB01                 4F100 AA00A AG00 AK01A AK49                       AK52 AN00A AN00B AN00C                       AT00A BA02 BA03 BA07                       BA10B BA10C DA11 DG00A                       GB41 JJ03A JJ03B JJ03C                       JK07B JK07C JL04A

Claims (5)

[Claims] 1. A base material layer for suppressing at least radial expansion of the belt is disposed in the thick portion, and at least an inner layer portion of the belt is made of a heat-resistant rubber-like elastic body. A characteristic fixing belt. 2. The fixing belt according to claim 1, wherein the base material layer for suppressing the elongation is an inorganic fiber. 3. The fixing belt according to claim 2, wherein the inorganic fibers are arranged in a composite layer of a heat resistant rubber-like elastic body or a heat resistant resin. 4. The fixing belt according to claim 1, wherein the outer layer portion of the belt is made of a heat resistant rubber-like elastic body or a heat resistant resin. 5. The fixing belt according to claim 1, wherein the thickness of the belt is 500 μm or less.