Unveiling (除 膜) compositions and methods for removing the lining equation (耐 膜 蝕)

摘要

These stripping compsns.consists of (i) 50-75 wt.% esp. 73 wt.% of 2- pyrrolidinone compd. having formula (I) e.g. 1-methyl-2pyrrolidinone, (ii) 20-45 wt.% esp. 27 wt.% of diethyleneglycole monoal kylether having formula HOCH2CH2-O-CH2CH2-O-R1 e.g. 2-(2ethoxyethoxy)ethanol and (iii) 5-30 wt.% of polethyleneglycole. In the formula, R=H, C1-3 alkyl or C1-3 hydroxyalkyl, R1=C1-4 alkyl. These novel compsns. do not contd. water, but that is not necessary condition. This comprises contain up to 10 wt.% of water.