摘要:
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.
摘要:
The invention relates to a cathodic electro-dipping process, which comprises a procedure in which the electro-dipping primer used contains an adduct containing urethane groups which is obtainable by reacting with one another a polyester-polyol or polyether-polyol, a polyisocyanate and a compound which contains a hydroxyl group and at least one ketimine group in the molecule.
摘要:
Polyamidoimide coatings having a long shelf life are prepared by a process in which a tricarboxylic anhydride, some of which may have been replaced by tetracarboxylic dianhydrides or dicarboxylic acids, is reacted with a polyisocyanate possessing 2 or more isocyanate groups in an organic solvent which is inert to isocyanate groups, from 0.7 to 0.98 isocyanate group being employed per anhydride and carboxyl group, and completely blocked polyisocyanate being added to the reaction mixture before, during or after the reaction in an amount such that the ratio of the total amount of anhydride and carboxyl groups employed to the total amount of isocyanate groups used, including those present in blocked form, is from 1:1 to 1:1.1.The polyamidoimide coatings are useful for coating electric conductors.
摘要:
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.
摘要:
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 formulaROOC--CH.sub.2 --O--(CH.sub.2).sub.2 --O--.sub.n CH.sub.2 --COORwhere R is hydrogen or alkyl of 1 to 6 carbon atoms and n is 0 or an integer from 1 to 10, in a water-soluble organic solvent and/or water, at from 80.degree. to 200.degree. C. These polycondensates are useful as wire enamels, impregnating agents and adhesives.
摘要:
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
摘要:
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.
摘要:
The invention relates to a cathodic electro-dipping process wherein the electro-dipping primer employed contains a crosslinking agent which can be obtained by(I) reacting, in a first stage,(a) diphenylmethane diisocyanate and(b) a monoalcohol or a mixture of monoalcohols to give an intermediate product (A) containing isocyanate groups, and(II) reacting this intermediate product (A) in a second stage with(c) a polyol or a mixture of polyols to give an intermediate product (B) containing hydroxyl groups which(III) is reacted in a third stage either with(d) a cycloaliphatic, aliphatic or araliphatic polyisocyanate or a mixture of such polyisocyanates and(e) a monofunctional masking agent or a mixture of such masking agents or with(f) a partially-masked polyisocyanate prepared from (d) and (e)to give a crosslinking agent which is free from isocyanate groups.
摘要:
The present invention relates to a process for the multilayer coating of substrates with electrodeposition and powder coating materials, in which electrodeposition is used to apply at least one coat (2) of electrodeposition coating material to the substrate (1), after deposition the substrate (1) is, if desired, wholly or partially air-dried, a coat of powder coating material (3) is then applied, and finally electrodeposition coating material and powder coating material are jointly baked.
摘要:
The invention relates to three-layer metal pipe coating compositions based on a powder primer, on a thermoplastic hard adhesive and on a polyolefin cladding. The powder primer contains epoxidized novolak resins, phenolic crosslinking agents and fillers based on crystalline silicic acid modifications. The invention likewise relates to a process for the exterior coating of metal pipes by a three-layer method, in which the powder primer described is applied to the metal pipe, a thermoplastic hard adhesive is applied to the powder primer, and subsequently a polyolefin cladding is applied.