| 摘要 |
The free formaldehyde content in amino formaldehyde resins is reduced to below 1% by weight by treating the resin with an aldehyde or ketone having at least one hydrogen bonded to a carbon itself directly bonded to the carbonyl carbon atom. The free formaldehyde content can be reduced still further, when a ketone is used, by additionally using ammonia or a primary or secondary nitrogen containing base. The resulting resins can be used conventionally but environmental pollution and health hazards are reduced. |
