Abstract: Mixtures which can be cured to give moulded materials having technically valuable mechanical and dielectric properties, characterized that they contain(a) polyimides of maleic acid or citraconic acid,(b) derivatives of .beta.-amino-crotonic acid, and optionally(c) polyamines.

Abstract: New bis-imides and tris-imides of the formula ##STR1## in which A and A' denote aromatic radicals which are optionally substituted or interrupted by an oxygen atom, an alkylene group or a sulphonyl group, Z denotes a radical of the formulae ##STR2## D denotes an oxygen atom or sulphur atom, m denotes the number 1 or 0 and n denotes the number 2 or 3, are obtained by cyclizing dicarboxylic acid monoamide compounds of the formula ##STR3## WITH ELIMINATION OF WATER. The bis-imides and tris-imides, mixed with azomethines and optionally with curing catalysts, can be used for the manufacture of moulded materials having technically very valuable mechanical and dielectric properties.

Abstract: According to the invention, polyaddition products containing imide groups are manufactured by reacting certain polyimides (preferably maleimides) with polyhydric alcohols in the presence of basic compounds. The preferred embodiment (E) relates to the use of catalysts as basic compounds. In particular, amines and alkali metal compounds can be used. A further embodiment (F) relates to the use of primary polyamines as basic compounds. In the latter case, the polyamine participates in the polyaddition mechanism, that is to say the molecules are incorporated into the polyaddition products. In this latter case, catalysts can also be used additionally.

Abstract: According to the invention, polyaddition products containing imide groups are manufactured by reacting certain polyimides (preferably maleimides) with polyhydric phenols in the presence of basic compounds. The preferred embodiment (A) relates to the use of catalysts as basic compounds. In particular, tertiary, secondary or mixed tertiary-secondary amines can be used. A further embodiment (B) relates to the use of primary polyamines as basic compounds. In the latter case, the polyamine participates in the polyaddition mechanism, that is to say the molecules are incorporated into the polyaddition products. In this latter case, catalysts can also be used additionally.The invention can be utilized particularly in the fields of surface protection, the electrical industry, laminating processes and the manufacture of foamed plastics, and in the building industry.

Abstract: New bis-imides and tris-imides of the formula ##EQU1## in which A and A' denote aromatic radicals which are optionally substituted or interrupted by an oxygen atom, an alkylene group or a sulphonyl group, Z denotes a radical of the formulae ##EQU2## D denotes an oxygen atom or sulphur atom, m denotes the number 1 or 0 and n denotes the number 2 or 3, are obtained by cyclizing dicarboxylic acid monoamide compounds of the formula ##EQU3## WITH ELIMINATION OF WATER. The bis-imides and tris-imides, mixed with azomethines and optionally with curing catalysts, can be used for the manufacture of moulded materials having technically very valuable mechanical and dielectric properties.

Abstract: A mixture which can be converted to a heat-resistant foamed plastic and which contains a polyimide of an unsaturated dicarboxylic acid, an azomethine, a solid blowing agent, and optionally a polyamine. On warming, the mixture gives a foamed plastic of high heat resistance and good resistance to chemicals.

Abstract: A mixture which can be converted to a heat-resistant foamed plastic and which contains a solid blowing agent, a thermoplastic prepolymer of a polyimide of an unsaturated acid, an azomethine and a polyamine. On warming, the mixture gives a foamed plastic of high heat resistance and good resistance to chemicals.