HYDROXYPROPYLMETHYL CELLULOSE PHTHALATE AQUEOUS DISPERSION FOR COATING - PREPARATION BY A NANOPRECIPITATION METHOD

Hydroxypropylmethyl cellulose phthalate (HP 55) pseudolatex was prepar ed using a recently patented process. This consisted in dissolving HP 55 in a water-miscible organic solvent followed by its precipitation i n water containing a surfactant. This method did not require emulsific ation or sonication and allowed the preparation of a pseudolatex chara cterized by small particle size, good stability and high polymer conce ntration. Films prepared by casting from the dispersion were compared to those obtained from the organic solution of the polymers. The resul ts demonstrated the possibility of obtaining HP55 in an ultra-disperse d system for coating use.