POLYMER COMPOSITION FOR PRODUCING HOLLOW MICROSPHERES Russian patent published in 1998 - IPC

FIELD: production of hollow microspheres for use in oil extracting industry for making drilling fluids and sorbents; may be used in mechanical engineering, aviation, space research and ship-building for making light-weight high-strength materials, etc. SUBSTANCE: composition comprises liquid resol phenolformaldehyde resin with molecular weight 700-1000, surfactant, pore-forming agent and, additionally, alkali metal hydroxide taken in the following ratio, wt.pts: phenolformaldehyde resin, 100; surfactant, 0.01-3.00; pore-forming agent, 0.05-7.00; alkali metal hydroxide, 0.01-3.00. Composition is prepared in reactor provided with stirrer and heating jacket. reactor is charged first with resin, then with pore-forming agent, surfactant and alkali hydroxide. Mixture is subjected to stirring for time sufficient to ensure uniform distribution of all components in resin (1.5 parts). Then mixture is heated up to temperature 70 C and directed to spray drier to be processed to microspheres. Solid hollow particles have continuous spherical shell with density 120-200 kg/cu.m, 100% buoyancy for 60 days and moisture absorption below 1.05%. EFFECT: lower density, higher buoyancy, moisture absorption and wettability. 2 tbl