| 摘要 |
High molecular weight polyoxymethylenes are produced by contacting substantially anhydrous formaldehyde in an inert organic solvent with a catalytic amount of an N-methylol, N-methylol ether or N-methylol thioether derivative of an organic nitrogen compound, the entire reaction being carried out under substantially anhydrous conditions. Catalytic agents specified in the examples are N-methylol phthalimide and succinimide, N, N1-dimethylol urea dimethyl ether, epsilon caprolactam-N-methylol methyl ether, ethyl carbamate N-methylol methyl ether, acetamide N-methylol methyl ether, N, N1-dimethylol thiourea diethyl ether and didodecyl thioether, melamine hexamethylol methyl ether, and the butyl ethers of a dicyandiamide-formaldehyde condensation product, a guanidine-formaldehyde condensation product, a dicyandiamideformaldehydeacetaldehyde condensation product and a urea-adipic acid dihydrazidehydrazocarbonamide-formaldehyde condensation product. Lists of other suitable catalytic compounds and classes of such compounds are provided. Suitable inert solvents are ethers, esters, aliphatic, cycloaliphatic and aromatic hydrocarbons and chlorinated hydrocarbons. The formaldehyde monomer may be added gradually to the reaction mixture as polymerization proceeds. The Specification refers to condensation products obtained from formaldehyde with a mixture of at least two members of the group consisting of urea, thiourea, guanidine or hydrazodicarbonamide, or other nitrogen-containing compound capable of forming methylol derivatives. In an Example (13), the condensation is described of formaldehyde with a mixture of urea, adipic acid dihydrazide and hydrazodicarbonamide, by heating the reactants in an aqueous suspension of barium hydroxide. The product obtained is etherified with butanol. |
