| 摘要 |
<p>Polyarylamines with methylene bridges are made by (a) reacting in the presence of a catalyst (i) aromatic amines with >=1H atom in the amine gp. and being unsubstd in >=1 of the posns 2,4, or 6 and (ii) aliphatic aldehyde, to form a precondensate; (b) removing the water present at the end of the reaction and (c) reacting the resulting precondensate in the presence of acid salts of aromatic amines, their condensation prods with satd aliphatic aldehyde or mixts of these in inert polar org. solvents which are soluble in water, opt. in the presence of water, or in the presence of aq. mineral acids or aq. acid salts of aromatic amines, opt. in the presence of inert polar org. solvents, and extracting the catalyst by washing with water and re-using it or neutralising it with an alkali. Suitable starting materials are e.g. aniline, o-toluidine or o-chloroaniline and formaldehyde. Prods are useful e.g. in the prodn of polyisocyanates for polyurethane mfr. and as curing agents for epoxy resins.</p> |
