| 摘要 |
<p>New isocyanate- and isocyanurate gp.-contg. mixts. of cycloaliphatic and/or aliphatic polyisocyanates blocked with cyclic amidine blocking agents having formula (I) (where R is H, alkyl, cycloalkyl, aralkyl or aryl, and/or 2 R are components of a ring; and n is 2 or 3) consist, by wt., of 10-100% (I)-blocked isocyanurate, contg. at least 2 NCO gps. before blocking, and 0-90% (I)-blocked monomeric polyisocyanate. The total unblocked NCO gp. proportion can be less than 0.5 to 12%. The blocked isocyanate- and isocyanurate gp.-contg. mixts. are prepd. by first converting the polyisocyanates, by a standard process, into an isocyanurate mixt. contg. at least 2 free NCO gps. This intermediate prod. is then reacted with (I), pref. 2-phenyl-imidazoline, at 0-150 (80-120) deg.C. 0.5-1.1 (0.8-1) moles (I) are used for each NCO gp. equiv. The prods. are used as hardeners for thermoplastics contg. active H atoms, and form hardenable systems used as binders for electrophoresis powder lacquers, as storage-stable 1-component stoving lacquers, esp. for coil coating and for wire-insulation.</p> |
