PROCESS OF PREPARING VESICULATED POLYESTER GRANULES

摘要

Process of preparing vesiculated polyester granules A process of preparing aqueous slurries of vesiculated granules of crosslinked polyester resin wherein the granules have a maximum shrinkage on drying of 5% of the granule diameter. The formation of aggregates of granules in the large scale production of granules using a metal oxide, hydroxide or weak acid salt as base can be overcome by using a surfactant which comprises a species < IMG > where a = 5-12, X is an anion of pK1 less than 2 and R is an alkylene oxide chain composed of units selected from ethylene, propylene and butylene oxides. When alkylene oxide other than ethylene oxide is present in the chain, such alkylene oxide must not provide more than two units per chain and the chain must additionally comprise at least three ethylene oxide units. The granules prepared by the process are useful as matting and opacifying agents in, for example, coating compositions.