Urea formaldehyde resin prepn. - by oxidising methanol sepg. formaldehyde and reacting with urea (BE101176)

摘要

Urea-formaldehyde resins and adhesives are prepd. by (1) catalytically oxidising MeOH-with air, (2) condensing the obtd. gases, (3) separating the condensed prods. from the uncondensed prods, (4) cooling the uncondensed gases and washing in a washing column with a soln. contg. polymerised and cooled HCHO which retains the MeOH and HCHO contained in the gases, (5) distilling the soln. in step (3) to isolate a concn. aq. HCHO soln and MeOH, (6) distilling the soln. obtd. in step (4) to isolate MeOH and retain the HCHO, (7) combining the HCHO soln. obtd. in step (6) with the distilled prod. obtd. in step (5), and (8) mixing the conc. aq. HCHO soln. obtd. in step (5) with urea under such pH and temp. conditions so as to obtain the product.