Abstract: The present invention relates to solutions of polyamide-imides which can be spun and shaped, and to a process for their preparation.They contain 5 to 30% of a polyamide-imide in a solvent mixture comprising 40-80% by weight of butyrolactone and 20-60% of an aprotic amide solvent. They are obtained by the reaction, in butyrolactone as polycondensation solvent, of a diisocyanate, an aromatic acid anhydride, optionally an alkali or alkaline-earth metal dicarboxybenzenesulfonate, and optionally another aromatic diacid, the concentration of polyamide-imide being from 15 to 36%, followed by dilution in an amide solvent, at a temperature between 120.degree. and 165.degree. C.The solutions obtained are clear at room temperature, are storable, and possess improved color.

Abstract: Organonitrogen compounds bearing a labile hydrogen atom directly bonded to a reactive nitrogen function, e.g., nitrogen heterocycles or substituted anilines, are N-alkylated with an N-alkylating agent in the presence of inorganic base and at least one sequestering agent having the structural formula:N--CHR.sub.1 --CHR.sub.2 --O--(CHR.sub.3 --CHR.sub.4 --O).sub.n --R.sub.5 ].sub.3 (I)wherein n is a number ranging from 0 to 10, R.sub.1, R.sub.2, R.sub.3, R.sub.4, which may be identical or different, each represents a hydrogen atom or an alkyl radical having 1 to 4 carbon atoms, and R.sub.5 represents an alkyl or cycloalkyl radical having 1 to 12 carbon atoms, a phenyl radical, or a radical of the formula --C.sub.m H.sub.2m --.phi., or C.sub.m H.sub.2m+1 --.phi.--, m ranging from 1 to about 12 and .phi. being phenyl.

Abstract: Novel imido copolymers, useful for the production of a variety of shaped articles, e.g., by molding, are prepared by reacting an oligoimide with an aromatic compound bearing labile hydrogen atom(s) on the nucleus thereof, or by co-reacting such oligoimide and aromatic compound with a polyamine.

Abstract: Polyamines possessing imide groups are obtained by heating at least one unsaturated polyimide of the general formula: ##STR1## WITH AT LEAST ONE POLYAMINE OF THE GENERAL FORMULA:Z(NH.sub.2).sub.bin which a and b each independently represents a number ranging from 2 to 6, Y represents an organic radical of valency a and Z represents an organic radical of valency b, in amounts such that the ratio of the number of NH.sub.2 groups introduced by the polyamine to the number of imide groups introduced by the polyimide is greater than 1 and at most equal to 5. These polyamines are useful for curing epoxy resins.

Abstract: Compositions are provided which consist of a solid suspension of:a. a prepolymer obtained by reacting a N,N'-bis-imide of an unsaturated dicarboxylic acid of general formula: ##STR1## in which D represents a divalent organic radical containing a carbon-carbon double bond and A represents a divalent organic radical possessing from 2 to 30 carbon atoms, and a polyamine of general formula:R (NH.sub.2).sub.xin which x represents an integer at least equal to 2 and R represents an organic radial of valency x, the bis-imide being used in an amount from 0.55 to 25 mols per mol of --NH.sub.2 group introduced by the polyamine, suspended in:B. water, and optionally,C. a polar water-miscible organic solvent having a boiling point between 110.degree. C and 270.degree. C in an amount up to 50% by weight of the liquid phase. These compositions are thixotropic and useful for coating and impregnating fibrous materials and the like from which valuable resinous composites can be obtained.

Abstract: Polyamines possessing imide groups are obtained by heating at least one unsaturated polyimide of the general formula: ##STR1## WITH AT LEAST ONE POLYAMINE OF THE GENERAL FORMULA:Z(NH.sub.2).sub.bIn which a and b each independently represents a number ranging from 2 to 6, Y represents an organic radical of valency a and Z represents an organic radical of valency b, in amounts such that the ratio of the number of NH.sub.2 groups introduced by the polyamine to the number of imide groups introduced by the polyimide is greater than 1 and at most equal to 5. These polyamines are useful for curing epoxy resins.

Abstract: A suspension of a maleamic acid is provided by reacting maleic anhydride with an appropriate diprimary diamine in an organic diluent in the presence of a tertiary amine. The suspension has a low viscosity and the maleamic acid can readily be recovered from it.

Abstract: An improved process for the dehydration of bis-maleic acids to bis-maleimides is provided which comprises heating the bis-maleamic acid with a lower carboxylic acid anhydride in acetone, in the presence of 0.2 to 1 mol of tertiary amine per mol of bis-maleamic acid and of a soluble nickel derivative and 0.1 to 10 mols of water per mol of bis-maleamic acid and precipitating the resulting bis-maleimide by the addition of water. The addition of water to the starting materials reduces the proportion of by-products produced and increases the degree of cyclodehydration.

Abstract: Maleamic acids of formula: ##EQU1## where R is a divalent organic radical and X is H or NHCOCH=CHCOOH are prepared in suspension as a flowing non-thixotropic fluid by a process wherein a solution of a primary monoamine or diamine in a solvent is run into a solution of maleic anhydride in a solvent in an amount such that there is an anhydride excess of 5 to 20 mol % relative to the theoretical amount necessary for the reaction with the amine, the mixture is agitated, the reaction temperature is 40.degree. to 130.degree.C., the time taken to run in the amine solution is at least 67 minutes, and the amine solution is run in at a rate such that the slope of the curve representing the variation, as a function of time, in the rate of running in as % of the total amount of amine solution employed per minute (acceleration) has, at every point on this curve, a value not greater than 0.044.