Rhone-poulenc Chimie

Rhone-poulenc Specialites Chimiques

Rhone-poulenc Industries

Rhone-poulenc Chimie De Base

Jean Robin

Andre Blind

Jean-Louis Locatelli

Gerard Collas

Ferenc Sagi

Michel Carlo

Jacques Lavorel

Storage-stable biuret polyisocyanates useful, e.g., for the production of paints and adhesives, are prepared by reacting at least one aliphatic, alicyclic or arylaliphatic diisocyanate with a biuret-forming reactant, in the presence of an effective amount of at least one organic carboxylic acid and/or anhydride thereof.

Storage-stable biuret polyisocyanates

Clear, precipitate-free, storage-stable biureto polyisocyanates, well adopted for paint applications, are prepared by reacting at least one aliphatic, alicyclic or arylaliphatic monomeric diisocyanate with water, at a temperature of at least 70.degree. C. and under an absolute pressure of at least 1.2 bar, including a partial pressure of carbon dioxide of at least 0.2 bar.

Preparation of biureto polyisocyanates

Substantially pure isocyanurate/polyisocyanates, i.e., containing no more than about 0.03% by weight of residual diisocyanate monomer and no more than about 1% by weight of diisocyanate dimer, are produced by extracting impure cyclotrimerized diisocyanates with an inert gas in either the liquid or supercritical state.

Substantially pure isocyanurate/polyisocyanates

Isocyanate condensates containing free NCO groups are separated and purified from crude reaction mixtures thereof which include unreacted excess di- or polyisocyanate monomer and at least one isocyanate antagonist, by extracting such crude reaction mixtures with an inert gas, notably carbon dioxide, in either the liquid or supercritical state; the highly purified isocyanate condensates are well adopted for the production of foams, elastomers, adhesives, paints and varnishes.

Isolation/purification of isocyanate condensates by extraction with

Polyisocyanates containing only trace amounts of free aromatic diisocyanates are recovered by purifying and isolating an isocyanate condensate containing free NCO groups from an impure admixture thereof, said isocyanate condensate impure admixture having been prepared by reacting a stoichiometric excess of an aromatic di- or polyisocyanate with a reactant compound containing at least two functional groups which are reactive with NCO groups, and such purification/isolation entailing extracting unreacted excess di- or polyisocyanate from said impure admixture with an inert gas, e.g., carbon dioxide, in either the liquid or supercritical state.

Purification/isolation of isocyanate condensates

Inert organic solvent solutions of polyisocyanates, well adopted as coating compositions, are storage-stabilized, e.g., against the formation of precipitates, by incorporating therein an effective amount of at least one organostannic compound which is soluble in the organic solvent.

Storage-stable organic solutions of polyisocyanates

Storage-stable polyisocyanurate-polyisocyanates, essentially devoid of polyisocyanate monomer and dimer over time, are conveniently prepared by catalytically cyclotrimerizing an aliphatic, cycloaliphatic or aromatic polyisocyanate in the presence of a catalytically effective amount of an aminosilyl catalyst, and terminating the cyclotrimerization reaction when predetermined desired amount of isocyanurate group has been reached, by adding to the reaction mixture a reaction terminating amount of water.

Catalytic partial cyclotrimerization of polyisocyanates and product

Polyisocyanurate/polyisocyanates of enhanced stability are prepared by partial catalytic cyclotrimerization of a polyisocyanate in the presence of a catalytically effective amount of an aminosilyl catalyst and wherein the cyclotrimerization reaction is terminated when a predetermined desired amount of isocyanurate groups has been attained, by adding to the reaction mixture, after the cooling thereof to a temperature of below 50.degree. C., a reaction terminating amount of an organic catalyst deactivating compound comprising at least one free hydroxyl moiety, or the reaction product of such hydroxylated organic catalyst deactivating compound with an isocyanate.

Process for preparing polyisocyanato/polyisocyanurates by catalytic

Polyisocyanato-polyisocyanurates are prepared by catalytically cyclotrimerizing a polyisocyanate in the presence of a catalytically effective amount of an aminosilyl catalyst, and which is characterizing by terminating the cyclotrimerization reaction when a predetermined desired amount of isocyanurate groups has been obtained, by adding to the reaction mixture a reaction terminating amount of an organic catalyst deactivating compound comprising at least one free hydroxyl moiety, or the reaction product of such hydroxylated organic catalyst deactivating compound with an isocyanate.

Catalytic cyclotrimerization of polyisocyanates

Monomeric or polymeric isocyanurates, e.g., polyisocyanate/polyisocyanurates, are prepared by catalytically cyclotrimerizing an isocyanate, e.g., an aliphatic or cycloaliphatic isocyanate, in the presence of an aminosilyl catalysis initiator, e.g., a mono- or diaminosilane, a silylurea or a silazane, having the structural formula:

Isocyanurate preparation by catalytic, aminosilyl initiated

A coating or molding composition including a polyisocyanate and an unsaturated imide, and having a ratio of total isocyanate functions to total polymerizable double bonds in the imide in the range of from 0.3 to 15, in addition polymerized to hard, imide group containing polymers characterized by the recurring unit: ##STR1## Coatings and shaped articles formed from such polymers are hard, tough, thermally stable, solvent resistant and are good insulators.

Polyisocyanato/imido compositions and imide group containing polymers

A coating or molding composition including a polyisocyanate and an unsaturated imide, and having a ratio of total isocyanate functions to total polymerizable double bonds in the imide in the range of from 0.3 to 15, is addition polymerized to hard, imide group containing polymers characterized by the recurring unit: ##STR1## Coatings and shaped articles formed from such polymers are hard, tough, thermally stable, solvent resistant and are good insulators.

A coating or molding composition including a polyisocyanate, an unsaturated imide and an olefinically unsaturated comonomer copolymerizable with the unsaturated imide, and having a ratio of total isocyanate functions to total polymerizable double bonds in the imide in the range of from 0.3 to 15, is addition polymerized to hard, imide group containing polymers characterized by the recurring unit: ##STR1## Coatings and shaped articles formed from such polymers are hard, tough, thermally stable, solvent resistant and are good insulators.

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Lyons, France

Jean Robin