CATIONIC RESIN PREPARED BY TWO STAGE CONDENSATION OF MELAMINE,FORMALDEHYDE AND ALIPHATIC HYDROXYLATED MONOAMINE

摘要

1305187 Alkanolamine - modified melamineformaldehyde resins BRITISH INDUSTRIAL PLASTICS Ltd 13 May 1970 [22 May 1969] 26265/69 Heading C3R [Also in Division D2] A modified melamine-formaldehyde resin is prepared by condensing melamine with formaldehyde and an aliphatic hydroxy monoamine, the molar ratio of formaldehyde to melamine being 2-6:1, at first at a pH above 8À5 in an aqueous medium, and then at pH 7À0-8À5, and at a solids content of reactants of at least 60% by weight throughout at least a major part of each stage; one or other of the melamine or the amine may be withheld from the first stage and added for the second stage. Preferably, 0À1-2 moles of amine are used per mole of melamine. In Examples 82% formaldehyde is mixed with water and triethanolamine, tri-n-propanolamine, diethylethanolamine or diethanolamine and condensed at pH 8À9-11À00, then melamine and HCl is added and condensation continued at pH 7À1-7À9; the product is diluted with water and neutralized with HCl; in Example 4, 36% formalin is used and the excess water removed by evaporation; in Example 5 the melamine is added in the first stage. Use.-Imparting wet strength to paper.