Polyurethane foil and coating prepn. - comprising tall oil pitch esterification with polyhydric alcohols and reaction with aliphatic triisocyanates

摘要

In the process (a) 100 pts. wt. tall oil pitch having acid index 30-60 and OH index 60-90 are esterified by (i) adding 5-15 pts. wt. aliphatic alcohol contg. >=3 OH gps. and 0.1-0.5 pts. wt. sulphonic acid, esp. p-toluenesulphonic acid, and (ii) heating under reduced press. until mixt. has acid index 5-35 and OH index 200-350; (b) tall oil pitch ester is admixed with an aliphatic triisocyanate, advantageously dissolved in an organic inert solvent. Amt. is such that quantity of isocyanate gps. is 10-35 pts. wt./100 pts. wt. tall oil pitch ester; (c) diluents and additives are added, followed by (d) depositing mixt. on a substrate and (e) polymerising foil or coating at room or higher temps. Hard and soft plastics are obtd., resistant to corrosion and chemicals. Foils are transparent, light-coloured, easily coloured, and resist temps. up to 240 degrees C.