| 摘要 |
The present invention relates to a process for producing melamine-urea-formaldehyde resins with up to 0.9% of melamine by reacting a) urea which comprises from 0 to 10% by weight of one or more compounds A, formaldehyde, and melamine in the presence of a base at a pH of from 7.5 to 11, at a temperature of from 20 to 120� C., and at a pressure of from 0.1 to 10 bar, b) and then carrying out reaction in the presence of an acid which optionally comprises urea with from 0 to 10% by weight of one or more compounds A, at a temperature of from 60 to 180� C., and at a pressure of from 0.1 to 10 bar, and c) and then adding urea which comprises from 0 to 10% by weight of one or more compounds A, which comprises carrying out b) at a pH of from 4 to 5.9. |
