Abstract: A middle petroleum distillate composition containing a major proportion of middle petroleum distillate and a minor proportion of an additive in a sufficient amount to limit the settling speed of paraffins contained in said middle distillate. Said additive consists of a product resulting from a reaction between at least one aliphatic dicarboxylic compound and at least one primary amine functional compound of general formula (I), wherein R1 is a monovalent saturated aliphatic radical, Z is selected from —NR?— groupings in which R? is a hydrogen atom or a monovalent saturated aliphatic radical, n is an integer between 2 and 4, and m is an integer between 1 and 4; said primary amine functional compound being used in a ratio of 0.3-0.8 mols per mol of said dicarboxylic compound.

Abstract: A middle petroleum distillate composition containing a major proportion of middle petroleum distillate and a minor proportion of an additive in a sufficient amount to limit the settling speed of paraffins contained in said middle distillate. Said additive consists of a product resulting from a reaction between at least one aliphatic dicarboxylic compound and at least one primary amine functional compound of general formula (I), wherein R1 is a monovalent saturated aliphatic radical, Z is selected from —NR′— groupings in which R′ is a hydrogen atom or a monovalent saturated aliphatic radical, n is an integer between 2 and 4, and m is an integer between I and 4; said primary amine functional compound being used in a ratio of 0.3-0.8 mols per mol of said dicarboxylic compound.

Abstract: The invention concerns a method for determining the temperature stability of a hydrocarbon mixture capable of phase separation by monitoring the weight variations of a gravimetric sensor part of which is immersed in said mixture. The method consists in: a first step of accelerated cooling of said mixture to a predetermined temperature; and a second step during which said mixture is maintained at this temperature, the time-dependent variation curve of said weight enabling the determination of the resulting solid mass and the separation speed of the two phases by determining the slope of this curve, the stability of said mixture being obtained by comparison with hydrocarbon mixtures of which the stability in time at low temperature between 0 and -30.degree. C. has been controlled.

Abstract: Additive composition enhancing the low temperature operability of average distillates beyond -20.degree. C. comprising at least 40% by weight of a composition consisting of: i) from 60 to 94% by weight of an antisedimentation additive resulting from the reaction of at least one aliphatic dicarboxylic compound and one polyamine of general formula (II) wherein R is a saturated aliphatic radical comprising from 1 to 32 carbon atoms, n is 2-4 and m is 1-4; and ii) 6-40 % by weight of a dispersing-stabilizing additive having a molecular weight varying from 15000 to 50000 resulting from the esterification reaction of a linear alcohol having from 6 to 24 atoms with an organic acid such as maleic acid and its halides, the ester obtained being polymerized with itself or a copolymerizing compound selected from aliphatic dicarboxylic compounds.

Abstract: Amine phosphate having a terminal imide cycle resulting from the reaction, under formation conditions for an amine salt, of at least one phosphate complying with the general formula (I): ##STR1## in which n is equal to 1 or 2, R.sup.1 is a divalent hydrocarbon group having 1 to 32 carbon atoms, R.sup.6 stands for a hydrogen atom or a hydrocarbon group normally having 1 to 200 carbon atoms, with at least one amine. Preparation process in accordance with standard methods and use of these compounds as additives in fuels for engines, if appropriate in formulations containing a second constituent consisting of at least one product chosen from among the germination additives of paraffins, whereby said formulations can also contain at least one paraffin crystal growth inhibiting product.