JPH0333785A - Multilayered endless film composition for fixing - Google Patents

Abstract

PURPOSE:To hardly generate the defects of a coated film and to smooth a surface as well as to obviate the degradation in characteristics as a surface layer, such as offset property, by forming a base layer of a polyimide resin and forming a surface layer of a organopolysiloxane. CONSTITUTION:A polyamic acid soln. is diluted with N-methyl-2-pyrrolidone to prepare a coating compd. of 20CP viscosity. One-component cold setting type silicone rubber (RTV) is then diluted with toluene to prepare a coating compd. of 300CP viscosity. The outside surface of a prescribed cylinder is dip coated with the polyamic acid coating compd. and is dried; thereafter, the surface thereof is calcined to convert the coating compd. to polyimide and thereafter, the molding is removed from the mold to obtain the polyimide resin (PI) film. The PI film is again press-fitted to the cylinder and after a primer is applied thereon, the coated film of the one-part RTV coating compd. is formed by a dip coating method thereon and is rested to obtain the endless film consisting of the three layers. The defects of the coated film are decreased and the smooth surface and the good offset property are obtd. by using the organopolysiloxane as the surface layer in such a manner.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a multilayer endless film composition for fixing that is installed in an image forming apparatus such as an electrostatic copying machine.

[Back-flying technology] is used, but when fluororesin is used as the surface layer, the melt viscosity during firing is high, the ringability is small, and cracks are likely to occur in pigment dispersion systems. There was a problem.

[Objective of the Invention] The object of the present invention is to solve the above-mentioned problems by using a material that is less likely to cause coating defects, has a smooth surface, and does not reduce the properties of the surface layer such as offset property. Settled. A multilayer endless film composition for fixing is provided.

[Summary of the Invention] The present invention relates to a multilayer fusing multilayer endless film composition having a support layer and a surface layer.

[Detailed Description of the Invention] In the present invention, organopolysiloxane, room temperature curable silicone rubber (hereinafter abbreviated as PTV), low temperature curable silicone rubber (hereinafter abbreviated as LTV), or high temperature curable silicone rubber (hereinafter abbreviated as HTV) It is preferable that

In order to achieve the above object, in the multilayer endless film composition for fixing of the present invention, an organopolysiloxane such as RTV, LTV or HTV is used in the surface layer, and if necessary, a viscosity of 10 to 100 OOO is added to the surface layer.
Ocs liquid organopolysiloxane, inorganic carbons,
Fillers such as oxides may also be added. Examples of inorganic carbons include carbon black and graphite, and examples of oxides include alumina, titanium oxide, tin oxide, and silica.

[Example 1] 7 volumes of polyamic acid and 100 parts by weight of N-methyl-2
- A paint having a viscosity of 20 CP was prepared by diluting with 300 parts by weight of pyrrolidone. Next, 100 parts by weight of overnight RTV was diluted with 300 parts by weight of toluene to prepare a paint having a viscosity of 300 CP.

A polyamic acid paint was dip-coated on the outer surface of a cylinder with a diameter of 50 mm and a length of 250 mm, dried at 120° C. for 30 minutes, baked at 380° C. for 30 minutes to imidize, and then demolded to obtain a PI film.

The PI film was again press-fitted into the cylinder, and after coating with the brimer by spraying, a coating film was formed with the acidic RTV paint by dip coating. After being left in this state for 7 days in an atmosphere with a temperature of 25°C and a relative humidity of 60%, the surface roughness Rz of the three layers was 0.3 to 0.4 μm and DiJ! la~22μ
An endless film of m was obtained.

When this endless film was set in a fixing device and the toner image on the paper was fixed at a film surface temperature of 185° C., no offset occurred.

[Example 2] The same polyamic acid paint as in Example 1 was used. The surface layer paint was prepared by diluting 100 parts by weight of -liquid RTV with 300 parts by weight of toluene and thoroughly dispersing 50 parts by weight of graphite having an average particle size of 7 μm.

Same person as Example 1? A three-layer endless film was obtained under the following conditions. When the fixability was confirmed in the same manner as in Example 1,
No offset occurred.

[Comparative Example 1 The same copolyamic acid paint as in Example 1 was used. The surface layer paint is an open fluorinated ethylene resin (hereinafter abbreviated as PTFE) with a solid content of 40% and a solid content of 100% dispersed acid.
50 parts by weight of graphite having an average particle size of 7 μm were sufficiently dispersed in each part by weight.

Using the same cylinder as in Example 1, a coating film of polyamic acid was formed by the dip coating method, and after coating the brimer by spraying, a PTFE paint was applied by the dip coating method.
Coated. After baking at 400° C. for 20 minutes, the mold was removed to obtain a three-layer endless film.

When the fixing properties were confirmed in the same manner as in Example 1, offset occurred and there was no problem in practical use.

[Effects of the Invention] As described below, according to the multilayer endless film composition for fixing of the present invention, by using organopolysiloxane as the surface layer, ■ there are few layer defects, ■ the surface is smooth, and ■ offset. A five-layer endless film with good properties can be easily provided.

Claims (2)

[Claims] (1) A multilayer endless film composition for fixing having a support layer and a surface layer, wherein the support layer is formed from a polyimide resin and the surface layer is formed from an organopolysiloxane. (2) The multilayer endless film composition for fixing according to claim 1, wherein the organopolysiloxane is a room temperature curable silicone rubber, a low temperature curable silicone rubber, or a high temperature curable silicone rubber.