Basf Aktiengesellschaft

Schenectady International Inc.

Basf Coatings Ag

Dr. Beck & Co Ag

Helmut Lehmann

Udo Reiter

Jenoe Kovacs

Hans-Uwe Schenck

Klaus-Wilhelm Lienert

Gerold Schmidt

Hans Jung

Wilhelm Dussel

Hans Schupp

Horst Reimann

Walter Disteldorf

Klaus Wilhelm Lienert

Ferdinand Hansch

Peter Hoessel

Hans-Josef Oslowski

Michael Wolfgang Muller

Irmgart Gebert

Klaus-Wilhelm Liener

A coating for enamelled wire having a base coat and a top coat, and enamelled wire having such coating. The top coat contains a binder, titanium dioxide and pyrogenic silica.

Coating which is resistant to partial discharges, for enamelled wire

The invention relates to wire enamels comprising as binders polyesterimide and/or polyamideimide, the binders comprising as monomeric building blocks polyoxyalkylenediamine having terminal amino groups. The polyoxyalkylenediamines are preferably selected from the group polyoxyethylenediamine, polyoxypropylenediamine and polyoxyethylenepropylenediamine. The invention also encompasses the use of the novel wire enamels for coating copper wires, especially thick round wires or profiled wires.

Wire enamels containing polyesterimides and/or polyamideimides with polyoxyalkylenediamines as molecular elements

Wire enamel formulation with internal lubricant

Self-bonding enamel solution for heat-resistant coatings

Heat-curable hot-melt enamels, a process for their preparation, and the production of highly heat-resistant wire windings. These heat-curable hot-melt enamels are solutions of a nylon in organic solvents, which contain, as the nylon, a nylon possessing functional amino groups and additionally contain a blocked di- or polyisocyanate. They are useful for the production of highly heat-resistant wire windings.

Heat-curable hot-melt enamel and its preparation

The purpose of the invention is to manufacture varnish-bonded thread-covered circular-section and profile-section wires and braided conductors in a manner which is particularly cheap and which involves particularly little risk of contaminating the environment. Suitable thread-covered wires and braided conductors are obtained by impregnation, in one operation, with partially crystalline or amorphous thermoplastic polycondensates.

Impregnation of thread-covered wires and braided conductors by extrusion

Aqueous thermosetting electrical insulating varnishes are prepared by a process wherein hydroxyl-containing polyester-imides which have kinematic viscosities of from 16 to 30 mm.sup.2 .multidot. s.sup.-1 and acid numbers of &lt;10, and which have been obtained by condensing aromatic tricarboxylic acid monoanhydrides, aromatic dicarboxylic acids or their esterifiable or transesterifiable derivatives, diamines, diols, and triols containing an isocyanurate ring, are treated, at from 80.degree. to 130.degree. C., in the presence or absence of up to 5% by weight, based on polyester-imide, of an organic solvent, with from 5 to 15% by weight, based on polyester-imide, of ammonia in the form of an aqueous solution, thereby producing aminolysis and hydrolysis so that a neutral or slightly acidic solution results, which is diluted to a viscosity of from 100 to 10,000 mPa.s by adding demineralized water, from 0.1 to 5% by weight, based on polyester-imide, of a water-soluble curing catalyst being added, if desired, after the treatment with ammonia. The electrical insulating varnishes are used as wire enamels or as impregnating varnishes.

Preparation of aqueous thermosetting electrical insulating varnishes

A process for the preparation of aqueous thermosetting electrical insulating varnishes, wherein polyester-imide precondensates are prepared by condensing aromatic tricarboxylic acid monoanhydrides, diamines, diols, triols containing an isocyanurate ring, and cyclic trimerization products of diisocyanates, whose free isocyanate groups are blocked, with or without aromatic dicarboxylic acids or their esterifiable derivatives, and are reacted, at from 50.degree. to 200.degree. C., with or without addition of from 1 to 10% by weight, based on polyester-imide, of a polar organic solvent, with ammonia or an organic amine, and then diluted with fully demineralized water, with or without addition of a water-soluble curing catalyst. The novel electrical insulating varnishes are used as wire enamels or impregnating varnishes.

Preparation of aqueous thermosetting electrical insulating varnishes,

Thermosetting polycondensates containing amide and imide groups which are obtained by reacting 1,2,3,4-butanetetracarboxylic acid or its anhydride with one or more aliphatic, cycloaliphatic or aromatic diamines and one or more oxadicarboxylic acids or oxadicarboxylic acid esters of the general formula

Thermosetting polycondensates containing amide and imide groups, and

A process for the electrical insulation of wire by enamelling, using aqueous dispersions which are applied thereto by means of applicator rollers. The thickness of the dispersion coating on the wire can be varied by merely suitably selecting the circumferential speed of the applicator rollers.

Electrical insulation of metallic conductors

A process for the electrical insulation of metallic conductors by coating wires with aqueous dispersions of coating materials, comprising the following steps which are carried out in a single cycle: introducing the starting dispersion into a storage zone A; continuously withdrawing part of the dispersion from the storage zone and feeding said part to a dispersing zone, where it is homogenized and comminuted; if necessary, cooling the dispersion to below 40.degree. C in a cooling zone; feeding the dispersion to a fractionating zone D, where it is separated into a coarse fraction and a fine fraction; and finally, passing the fine fraction through coating zones E, through which wires are drawn so as to receive a coating.

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Reinbek, Germany

Helmut Lehmann