RU2007766C1 - Method of insulating polyimide film making - Google Patents

Abstract

FIELD: electrical engineering. SUBSTANCE: method involves loading of solvent (dimethylformamide or dimethyl- acetamide) and 4,4-diaminodiphenyl ester into reactor, stirring, loading of pyromellitic acid dianhydride, stirring, film pouring off, its cyclization and orientation. Dianhydride is loaded by two stages: 18,1 mas. p. at the first stage and 0,225-0,625 mas. p. at the second one. Polymethylphenylsiloxane liquid (0,20-3,52 mas. p. ) is loaded between these stages, and stirring is carried out at 15-25 C. EFFECT: improved method of polyimide film making. 1 tbl

Description

 The invention relates to electrical engineering, mainly to a technology for the production of insulating heat-resistant materials.

 A known method of producing a polyimide (polypyromellitimide) film, in which first polyamide acid in an amide type solvent is prepared from pyromellitic dianhydride and 4,4'-diaminodiphenyl ether, then the polyamide acid solution is cast in the form of a film, which is converted into imide by ring-closed reaction at elevated temperatures .

 However, the polyimide film obtained by this method has insufficiently high electric strength and adhesive properties, and high values of the coefficient of friction and roughness make it difficult to wind the film in a high-quality manner.

 A known method of producing a polyimide film, in which titanium compounds are added to the polyimide before casting.

 However, the introduction of titanium into the polyimide does not increase its electrical characteristics.

 The purpose of the invention is to improve the quality of the resulting film by improving its electrical insulating and mechanical characteristics.

 Using the proposed method for producing a polyimide film will simplify the process of casting the film and winding it into a roll by reducing the roughness and coefficient of friction, increasing the slip of the film on the film and on the metal, which leads to an increase and preservation of the quality of the finished film. In addition, the proposed method allows to obtain a polyimide film of smaller thickness for use as film insulation of capacitors, cables and wires, the basis of magnetic media, metallized and foil dielectrics, as well as in multilayer electrical insulating materials due to improved electrical characteristics and adhesive properties.

The essence of the method for producing an electrical insulating polyimide film is that an amide solvent and 4,4'-diaminodiphenyl ether are loaded into the reaction vessel, mixed, pyromellitic acid dianhydride is loaded, and mixed until a viscosity is sufficient for processing into the film, the polyamide acid solution is cast from the resulting solution the film and produce its orientation and imidization, characterized in that dimethylacetamide or dimethylformamide is used as a solvent, dianhydride is charged in two stages, said step ezhdu charged 0.20. . . 3.52 wt. including polymethylphenylsiloxane fluid, in the first stage load of 18.1 wt. including dianhydride, and in the second 0.225. . . 0.625 wt. o'clock, while mixing after the first stage of loading dianhydride and after loading polymethylphenylsiloxane liquid is carried out at 15.. . 25 ^about With for 50.. . 70 min, and mixing after the final loading of dianhydride is carried out until the solution reaches a viscosity of 3000.. . 5000 Poise at a temperature of 20.. . 30 ^о С for 50.. . 70 min

 The invention is as follows.

In the reaction vessel load 210 wt. including dimethylformamide or dimethylacetamide and enter 17 wt. including 4.4 '- diaminodiphenyl ether, stirred at 15 ^about C for 60 minutes, 18.1 wt. including pyromellitic acid dianhydride and stirred at 20 ^about C for 50 minutes, enter 0.20; 0.36; 0.98; 2.45 and 3.52 wt. including polymethylphenylsiloxane liquid and stirred at 25 ^about C for 70 min, pyromellitic acid dianhydride is introduced in an amount of 0.225. . . 0.625 wt. hours to obtain a solution viscosity of 3000.. . 5000 poise after stirring at ²⁵ ° C for 65 min, cast film and imidization is carried out while increasing the temperature to 300. . 350 ^about With the simultaneous orientation by drawing the film in the longitudinal direction.

 The adhesive properties (adhesion strength) of the obtained film to adhesive compositions based on organosilicon, epoxy, polyurethane, polyamide, polyester and other compounds increases by 20.. . 50%, and when processing the film by corona discharge or ion-plasma irradiation by 50.. . 300% The values of dielectric strength (Epr.), Coefficient of friction, and film roughness are given in the table. (56) U.S. Patent No. 4,742,099, cl. C 08 K 5/52, 1988.

USSR copyright certificate
N 329188, CL C 08 G 3/10, 1969.

Claims (1)

METHOD FOR PRODUCING ELECTRIC INSULATION POLYIMIDE FILM, in which the amide solvent and 4,4-diaminodiphenyl ether are loaded into the reaction vessel, mixed, pyromellitic acid dianhydride is mixed, stirred until a viscosity is sufficient for processing into the film, the film is cast from the resulting polyamide acid solution and the film is cast orientation and imidization, characterized in that, in order to improve the quality of the resulting film by improving its electrical insulation and mechanical characteristics, as a -solvent used dimethylacetamide or dimethylformamide dianhydride were charged in two steps, between said stages charged 0.20 - 3.51 wt. including polymethylphenylsiloxane fluid, in the first stage load of 18.1 wt. including dianhydride, and in the second 0.225-0.625 wt. o'clock, while mixing after the first stage of loading the dianhydride and after loading the polymethylphenylsiloxane liquid is carried out at 15 - 25 ^o for 50 - 70 minutes, and stirring after the final loading of the dianhydride is carried out until the solution reaches a viscosity of 300 - 5000 P at 20 - 30 ^o C within 50 - 70 minutes

Images