| 摘要 |
Etherified aminotriazine resins with a low formaldehyde content (e.g. 0.1 to 0.8% by wt.) are prepared by steam distilling a solution, in an organic solvent, of an etherified amino-triazine resin with a formaldehyde content of up to 10% by wt. The resin solution may be treated either prior to or after steam distillation with either: (1) a peroxide compound, e.g. H2O2, a peroxide, hyperoxide or sesquioxide of an alkali metal or alkaline earth metal, a peroxyacid or its salts with S, P, N, C or B, or a peroxy-hydrate,(2) sufficient ammonia to form hexamethylene tetramine with the residual HCHO or (3) a sulphur compound which is capable of forming either a HCHO-bisulphite or HCHO-sulphoxylate adduct. Examples of (3) are sulphites, pyrosulphites, dithionates, dithionites and sulphoxylates, alternatively SO2 may be used; it may either be neutralized afterwards with a strong base (e.g. NaOH) or passed into a solution which has been previously treated with a strong base. Examples relate to the preparation of paints with TiO2, an alkyd resin and aminotriazines resins both untreated and treated according to the invention. |
