Dialkylcarbonate compounds (A) are new. Dialkylcarbonate compounds (A) of formulae (R 1>；O-CO-OR 2>；) (I), (R 3>；O-CO-OR 4>；) (II), (R 5>；O-CO-OR 6>；) (III) and (R 7>；O-CO-OR 8>；) (IV), are new. R 1>；2-propyl-1-heptyl or 2-ethyl-1-butyl； R 2>；, R 4>；, R 5>；linear, branched or cyclic 1-22C hydrocarbon residues or 0-3 double bonds； R 3>；isodecyl residue, neodecyl residue, isoundecyl residue, isododecyl residue, isotridecyl residue, 2-pentylnonyl residue, 2-hexyldecyl residue, 2-heptyl undecyl-residue, isostearyl residue, 2-octyldodecyl residue, 2-butyl-1-octyl residue or 2-ethyl-1-hexyl residue； R 6>；more than 12C branched hydrocarbon residues or 0-3 double bonds； R 7>；branched 3-22C hydrocarbon residue or 0-3 double bonds； and R 8>；branched 1-22C hydrocarbon residue or 0-3 double bonds. Provided that: R 3>； is not equal to R 4>；, and R 7>； is not equal to R 8>；.
