GB1145952A - Isocyanate-containing oxadiazinones and the preparation thereof - Google Patents

Abstract

1,145,952. Isocyanate-containing oxadiazinones. FARBENFABRIKEN BAYER A.G. 2 Feb., 1967 [2 Feb., 1966], No. 5092/67. Heading C2C. [Also in Division C3] Isocyanate - substituted 1 - oxa - 3,5 - diazine trione-2,4,6 compounds may be obtained by reacting one or more aliphatic or araliphatic polyisocyanates in which the isocyanate groups are of substantially similar reactivity with carbon dioxide in the presence of a trisubstituted arsine oxide, a trialkyl phosphine or an aromatic-aliphatic tertiary phosphine as catalyst. The polyisocyanate starting materials contain aliphatically bound isocyanate groups of substantially similar reactivity and they may be reacted in admixture with aliphatic monoisocyanates. The amount of catalyst employed is suitably 0À01 to 10% by weight and the reaction may be effected at - 50‹ to 150‹ C., optionally in the presence of a solvent. The reaction may be continued until high molecular weight resins are formed or the catalyst may be inactivated by the addition of an acylating or alkylating compound before the isocyanate content has dropped to less than 60% of the initial value. The carbon dioxide employed in the reaction may be obtained by the addition of solid carbon dioxide, by carrying out the reaction in an autoclave under a carbon dioxide pressure of 5 atmospheres gauge or the carbon dioxide may be obtained by reacting part of the isocyanate groups with an active hydrogen-containing compound. In examples, specified isocyanates employed are hexamethylene diisocyanate, which may be admixed with butyl or 6-chlorohexyl isocyanate and tetramethylene diisocyanate; in Example 12, the product of reacting hexamethylene diisocyanate with carbon dioxide is treated with phenol to yield a urethane.