In addition to this main application, the esters of adipic acid with polyalcohols are used for alkyd resins and plastic materials. Othcr esters serve as plasticizers or as additives for lubricants. The hydrogenation of adipic acid at 170- 240 "C and 150-300 bar over Cu-, Co-, or Mn-catalysts, or of its ester, leads to the formation of 1,6-hexanediol, most of which is used for polyesters and polyurethanes. Another use involves the amination of 1,6-hexanediol to hexamethylenediamine (cf: Section 10.2. I).