Rhone-poulenc Industries

Rhone-poulenc S.a.

Max Gruffaz

Jean-Louis Locatelli

Maurice Balme

Bernard Rollet

Odile Micaelli

Gerard Lefebvre

Pierre Ledru

Jean L Locatelli

Carboxylic acids are esterified with ethylene gas, to effect the formation of ethyl esters, by acid catalysis in the presence of at least one dissociating, inert and stable solvent which increases the acidity of the reaction medium.

Preparation of ethyl carboxylates

In a process for the preparation of ethyl acetate by vapor phase reaction of ethylene with acetic acid, the improvement which comprises conducting said reaction in the presence of a catalytic amount of a solid, ion-exchange fluoropolymer comprising sulfonic acid moieties.

Catalytic preparation of ethyl acetate

Carboxylic acids are esterified with ethylene or propylene gas, to effect the formation of ethyl or isopropyl esters, respectively, by acid catalysis in the presence of a catalytic amount of a perfluoro sulfonic acid.

Preparation of ethyl carboxylate

A thermosetting composition is disclosed characterized in that it comprises (by weight) from 60 to 90% of a bis-maleimide of the formula: ##STR1## in which A represents a divalent radical chosen from the group consisting of phenylene radicals and radicals of the formula: ##STR2## where T represents --CH.sub.2 --, --C(CH.sub.3).sub.2 --, --O-- or --SO.sub.2 --; and from 10 to 40% of N-vinylpyrrolid-2-one. The preferred bis-maleimide is N,N'-(4,4'-diphenylmethane)-bis-maleimide. The composition may be modified by the addition of an unsaturated polyester. The composition is useful for the manufacture of molded articles or of articles having a cellular structure, or for the impregnation of electrical coils.

Thermosetting composition from bis-imide, N-vinyl pyrrolidone and

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:

Polyamines with imide groups

Thermosetting composition from a bis-maleimide and N-vinyl pyrrolidone

A curable composition is provided which comprises

Thermosetting compositions based on a bis-imide and a polyurethane

A polymer is disclosed that results from the reaction of:

Polymers with imide groups, and comprising a polyester free from

Polymers possessing imide groups having excellent heat resistance and chemical inertness are disclosed. They are prepared by reacting cyanamide and a product possessing imide groups selected from: A. a bis-imide of the general formula: ##STR1## in which Q represents a divalent radical of the formula: ##STR2## WHEREIN Y represents H, CH.sub.3 or Cl and m is 0 or 1, and A represents a divalent organic radical containing 2 to 30 carbon atoms; and B. a mixture comprising a said bis-imide and a mono-imide of the general formula: ##STR3## in which Q is as defined above and R represents a hydrogen atom or a monovalent organic radical containing 1 to 20 carbon atoms.

Polymers possessing imide groups

A cellular material is disclosed based on a polymer with imide groups, characterized in that it is obtained by heating a mixture comprising:

Heat-stable cellular materials

Curable compositions are provided based on an imide group-containing compound, an amino compound and a polyurethane elastomer in specified proportions. These compositions can be cured to give articles possessing excellent impact strength.

Curable compositions based on imide group-containing compounds

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.

Preparation of suspensions of maleamic acids

Polymers possessing imide groups are disclosed. These polymers display good impact strength and are obtained by reacting: A. a bis-imide of the formula ##EQU1## in which Y represents a divalent hydrocarbon radical with 2 to 20 carbon atoms which is free from unsaturated bonds other than aromatic bonds, a divalent mono- or bis-heterocyclic radical with 2 to 10 carbon atoms, or a divalent organic radical with 4 to 20 carbon atoms consisting of several of the hydrocarbon radicals defined above connected to one another by --O--, --S--, --CO-- or --SO.sub.2 --, and B. either an adduct (A) obtained by reacting an epoxy resin and a polyamine of the general formula:

Heat-resistant resins derived from a bis-imide, an epoxy resin and a

Multicellular polymers having excellent chemical inertness and heat resistance are produced by heating at a temperature from 100.degree. to 300.degree.C, maleic anhydride and a polyaldimine of the general formula

Maleic anhydride-polyaldimine prepolymers

Thermosetting polymers, both prepolymers and cured resins, are produced by reacting ammonia with a polyimide of the formula: ##EQU1## IN WHICH A IS A NUMBER FROM 2 TO 4, Y represents an organic radical of valency a, and A and T, which may be identical or different, each represent hydrogen, chlorine or methyl, the proportions of polyimide and ammonia being such that there are at least 2 imide groups per mol of ammonia. These polymers find utility in the production of materials liable to undergo severe heat stresses.

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La Mulatiere, France

Max Gruffaz