The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 23, 1982
Filed:
Jan. 05, 1981
Leslie R Hoy, St. Neots, GB;
Peter S Westgate, Welwyn Garden City, GB;
Imperial Chemical Industries Limited, London, GB;
Abstract
An aqueous dispersion of an aromatic polyethersulphone of sole repeat unit ##STR1## and having mean particle size below 25 .mu.m, preferably below 12 .mu.m, is prepared by (1) stirring the polyethersulphone in methylene chloride to form a solution and then a coarse particulate solid, (2) adding further methylene chloride to form a slurry, (3) milling the slurry to form a dispersion, (4) mixing a methylene chloride - and water-miscible liquid which does not swell the polyethersulphone with the milled dispersion, (5) filtering the dispersion and washing the wet cake with the liquid and then water, and (6) dispersing the wet cake in water, optionally with milling, to provide the aqueous dispersion.