Back to results
US 4,487,964 AGranted
Method of making mixed aliphatic/aromatic polycarbodiimides
AssigneeUnion Carbide Corporation
InventorsStuart L. Watson, Jr., Gordon R. Humphreys
Life of this patent
Estimating the term…
Abstract
Mixed aliphatic/aromatic polycarbodiimides can be prepared by first heating aliphatic mono- and diisocyanates with a phospholene oxide catalyst and then feeding the aromatic mono and/or diisocyanates in an inert solvent to the reaction mixture, thus preparing cross-linking agents for carboxylated latexes used in making roofing materials, hardboard, pressure sensitive adhesives and the like.
Claims9
Method of preparing mixed aliphatic and aromatic polycarbodiimides which comprises the following steps seriatim:
- (A) charging a mixture of cycloaliphatic or saturated aliphatic mono- and diisocyanates to a reactor with agitation under an inert atmosphere;
- (B) heating the resultant mixture to about 120.degree. to about 160.degree. C.;
- (C) adding a catalytic amount of a phospholene oxide catalyst to the reactor;
- (D) feeding a mixture of a non-reactive solvent and aromatic mono- and/or diisocyanate to the reactor;
- and
- (E) maintaining agitation at about 120.degree. to about 160.degree. C. until all of the isocyanate functionality is converted to carbodiimide functionality, with the provisos that:
- (a) said cycloaliphatic moieties contain 6 to about 10 carbons;
- (b) said saturated aliphatic moieties contain from about 4 to about 12 carbons;
- (c) said aromatic moieties contain from 6 to about 16 carbons;
- (d) The molar ratio of all of the mono-to-diisocyanates range from about 2:1 to about 2:10;
- and
- (e) The molar ratio of cycloaliphatic and/or saturated aliphatic isocyanate groups to aromatic isocyanate groups ranges from about 0.5:1 to about 2:1.
9 more elements
Dependencies are inferred from the claim text.