摘要 |
Use as lubricants, especially for tractive drives, of ester compounds of the general formula I <CHEM> wherein Cb denotes a carboxylic grouping which may be monocarboxylic (MCb) of formula -O-CO- or -CO-O-, dicarboxylic (DiCb) of formula -O-CO-R4-CO-O- or -CO-O-R4-O-CO-, or tetracarboxylic (TCb) of formula -O-CO-R5-CO-O-R6-O-CO-R5-CO-O-; R4 represents an optionally substituted alkylene or alkenylene group, a C5-10 cycloalkylene group, a di-(C5-10 cycloalkylene) group, or a C5-10 cycloalkenylene group; R5 represents an alkylene group and R6 represents a cycloalkylene group; each group R3 individually represents a C1-6 alkyl, C2-6 alkenyl, C3-20 mono- or polycycloalkyl group or a hydrogen atom; m and n are each 0 or 1; R1 represents an optionally substituted C4-10 tertiary alkyl group or an optionally substituted C3-8 cycloalkyl or C6-14 bicyclo or tricycloalkyl group; and R2 represents the same as R1 or alternatively represents an optionally substituted alkyl, alkenyl, mono- or polycycloalkyl, mono or polycycloalkenyl group; provided that when m and n are each 0 and Cb is MCb or DCb wherein R4 is cyclohexylene, then R1 and R2 are not both cyclohexyl. |