一步法密胺树脂的结构和性能

THE STRUCTURAL COMPOSITION AND PERFORMANCE OF MELAMINE-FORMALDEHYDE RESIN PREPARED BY ONE-STEP TECHNOLOGY

氨基树脂在各种保护涂料中广泛用作交联剂。为了满足高固体分卷板涂料的高技术性能要求,我(?)研制子一步法工艺,并中试(30公斤)成功合成了低聚合度、高反应性丁氧基甲基密胺树脂(BMM-90),采用化学分析方法,GPC和TG、DTG技术表征了其结构和反应性,并进行了卷板涂料漆膜性能评价、

In order to satisfy the needs of coil coating with high solid content (65％-70％) and excellent comprehensive properties, a butvlated melamine resin (BMM-90) with lower degree of polymerization and higher reactivity was successfully synthesized on 30-kg scale by one—step technology. It was shown that the contents of free formaldehyde and solid of BMM—90 were equal to that of two-step technology, 2.5％-3.5％ and 55％-60％. respectively, since the contents of oxidable formaldehyde (-CH_2OH and -CH_2O-) and methylene were the evaluation of reactivity and degree of self-condensation polymerization of melamine resin, respectively. BMM-90 had much more oxidable formaldehyde and less methylene than the commercially available (G-BMM), which agreed to the data of GPC. As shown by TG and DTG, the apparent activation energy of co-condensation of BMM-90 and polyester resin was 54.8kJ /mole, similar to that of HMMM-acrylate system (52.25K J/mole). A coil coating was prepared by mixing polyester. BMM-90, activated diluent and plasticizer. When roller applied to steel sheet and cured by electromagnetic induction at 220-240℃ for 10 seconds, it showed 2-3H pencil hardness, 2-3T bend. >100MEK double rubs and>9J reverce impact.