A container (1) for releasing a chemical additive (7) in a fluid material selected from a lubricant or hydraulic fluid composition comprises a fluid material-impermeable casing (3) having a hollow interior and an additive composition (7) comprising at least one fluid material-soluble additive. The additive...http://www.google.es/patents/US7581558?utm_source=gb-gplus-sharePatente US7581558 - Controlled release of additives in fluid systems
