Additives compositions useful in particular for improving the cold filterability properties of oil middle distillates

Additive compositions, useful in particular for improving the cold filterability properties of oil middle distillates, comprise: PA0 (A) at least one ethylene polymer; and PA0 (B) at least one polymeric compound resulting from the condensation of at least one compound comprising a primary amine group, of formula EQU R--Z[(CH.sub.2).sub.n NH].sub.m H or HO--CH.sub.2 --R"--NH.sub.2 PA0 wherein R is an alkyl from C.sub.1 to C.sub.30, Z is --NH--, --NR'-- or --O--, R' being a C.sub.1 -C.sub.30 alkyl, n an integrer from 2 to 4 , m an integrer from 1 to 4 (or zero when Z is --NH--), R" is a C.sub.1 -C.sub.18 alkylene, with a copolymer of a linear .alpha.-olefin, of an unsaturated .alpha., .beta.-dicarboxylic compound and of an alkyl ester of an unsaturated monocarboxylic acid, or a vinyl ester of a saturated monocarboxylic acid. These additive compositions, used for example at concentrations from 50 to 500 g/m.sup.3, have a synergic effect on the filterability limit temperature of the middle distillates, particularly gas-oils.

The invention concerns the combined use of additives having synergism 
properties, to improve the cold filterability of oil middle distillates, 
particularly gas-oils. It also concerns the oil middle distillates 
compositions comprising such additive combinations. 
The additive combinations according to the invention confer to the middle 
distillates to which they are incorporated very good general properties at 
temperatures. 
BACKGROUND OF THE INVENTION 
Many compounds have been proposed, in the prior art, as additives for 
improving the behavior at temperatures and more particularly the 
properties of cold filterability of oil middle distillates. 
They may consist of mere polymers such as, for example, ethylene 
homopolymers. Some of them are mentioned, by way of example, in the 
West-German Patent DE No. 856,682 and the U.S. Pat. No. 3,640,824, both 
describing the use of branched polyethylenes of high number molecular 
weight, whereas the british patent GB No. 847,777 and the U.S. Pat. No. 
3,454,379 recommended, on the contrary, the use of branched polyethylenes 
of low number molecular weight (lower than 5,000). 
However, the use of only branched polyethylene is not sufficient to obtain 
satisfactory properties of cold filterability; this is also true for the 
use of various copolymers of ethylene with another co-monomer such, for 
example, as vinyl acetate, .alpha.-olefins, esters or diesters having an 
olefinic double bond. 
Much better results concerning the improvement of cold filterability of oil 
middle distillates have been obtained by using mixtures of additives. 
Among the numerous disclosed compositions, those which do not comprise 
polyethylene as homopolymer or as a co-polymer may be first mentioned. 
Thus the French patent FR No. 2,347,435 discloses the synergic action of 
an alkyl-aromatic derivative associated either to a hydrogenated 
1,4-polybutadiene or to a hydrogenated copolymer of 1,4 polybutadiene with 
a second dialkene compound. U.S. Pat. No. 2,917,375 indicates the synergic 
properties of micro-crystalline paraffin waxes admixed with acrylic and/or 
methacrylic polymers. U.S. Pat. No. 4,140,492 mentions the synergic action 
of two compounds: the first one results from the action of boron compounds 
on Mannich bases of phenol compounds, while the second may be an amorphous 
hydrocarbon or a hydrogenated polybutadiene. 
Compositions wherein one of the constituents is an ethylene copolymer may 
also be mentioned. By way of example, U.S. Pat. No. 3,660,057 discloses 
the association of hydrocarbon fractions free of n-paraffins which 
copolymers of ethylene and .alpha.-olefins of 3 to 16 carbon atoms, or 
with copolymers of ethylene and acids, anhydrides or esters having an 
olefinic double bound. The U.S. Pat. No. 3,640,691 discloses the 
association of a minor paraffinic fraction, containing n-paraffins of 
24-40 carbon atoms with ethylene/vinyl acetate copolymers. French Pat. No. 
2,061,457 associates two copolymers of ethylene and vinyl acetate of 
different molecular weights. Japanese patent JP No. 57,209,995 discloses a 
synergic action between a residual heavy oil and a copolymer of ethylene 
with an ester of a carboxylic acid having ethylenic bonds. The European 
patent EP No. 0,074,208 discloses a synergic action on the filterability 
limit temperature of fuel oils between, on the one hand, a copolymer of 
ethylene and alkoxyalkyl(meth)acrylate and, on the other hand, a copolymer 
of ethylene associated either with a vinyl ether or with an alkyl ether of 
unsaturated acid. 
U.S. Pat. No. 3,961,916 teaches the synergism between two copolymers both 
composed of ethylene, copolymerized either with vinyl esters or with 
alkyl(meth)acrylates. U.S. Pat. No. 4,153,424 discloses the synergic 
effect of a copolymer of ethylene and alkyl acrylates associated with a 
homo- or copolymer of alkyl acrylate and/or methacrylate. Among these 
types of compositions having a synergic action, were also described 
compositions comprising three different compounds. Thus, the Japanese 
patent JP No. 56,043,391 discloses the synergic action of a chlorinated 
polyethylene, a branched polyethylene, an alkenyl-succinamide. U.S. Pat. 
No. 3,892,909 teaches a synergic effect of three compounds: 
(A) A mono-amide or mono-esterified derivative of an unsaturated 
dicarboxylic acid; 
(B) A copolymer of ethylene with an ester of an unsaturated mono- or 
di-carboxylic acid, a C.sub.3 -C.sub.16 .alpha.-olefin or vinyl chloride; 
and, 
(C) A micro-crystalline wax free of n-paraffins, or an alkyl aromatic 
compound. 
Finally, compositions wherein one of the constituents is polyethylene can 
be mentioned. 
Thus, U.S. Pat. No. 3,640,824 discloses the association of a highly 
branched polyethylene of number molecular weight higher than 6,000 with a 
micro-crystalline wax and/or with naphthalene and/or asphaltenes. 
U.S. Pat. No. 3,661,541 mentions the synergism betweeen: 
(A) polyethylene or a copolymer of ethylene with a 3-18 carbon atoms 
.alpha.-olefin, and 
(B) a copolymer of ethylene with an unsaturated carboxylic monoester. 
French patent FR No. 2,305,493 teaches the synergism between two compounds 
(A) and (B): 
(A) being either polyethylene or a copolymer of ethylene with esters having 
ethylenic unsaturations, and 
(B) being an alkyl poly(meth)acrylate. 
French patent FR No. 2,324,711 indicates the syngergism between: 
(A) polyethylene or chlorinated polyethylene or a copolymer of ethylene 
with an .alpha.-olefin or vinyl or (meth)acrylic ester, and 
(B) sulfonated copolymers obtained by reacting sulfurous anhydride with 
.alpha.-olefins mixtures. 
French patent FR No. 2,305,492 discloses the synergism between: 
(A) polyethylene or a copolymer of ethylene with either a vinyl ether, or 
an alkyl(meth)acrylate, or an .alpha.-olefin, and 
(B) alkyl poly(meth)acrylates. 
U.S. Pat. No. 3,166,387 discloses the synergic action of polyethylene of 
low molecular weight associated with a secondary or tertiary amine salt of 
carboxylic acid. 
French patent FR No. 2,490,669 discloses a synergic composition formed 
from: 
(A) polyethylene or chlorinated polyethylene or a copolymer formed from 
ethylene and alkyl acrylate or vinyl acetate or still a hydrogenated 
copolymer of butadiene and isoprene, and 
(B) the reaction product of linear N-alkyl polyamines with saturated or 
unsaturated cyclic anhydrides, optionally substituted with a hydrocarbon 
group comprising 1 to 6 carbon atoms. 
U.S. Pat. No. 4,019,878 discloses a composition having a synergic effect, 
formed by: 
(A) polyethylene or chlorinated polyethylene or a copolymer of ethylene 
with either an .alpha.-olefin or an unsaturated monoester, or an 
unsaturated diester, 
(B) bees-wax or ozokerite or a mixture of .alpha.-olefins havins 24 to 50 
carbon atoms. 
U.S. Pat. No. 4,175,926 indicates a composition having a synergic effect, 
obtained from: 
(A) polyethylene or a copolymer of ethylene with unsaturated mono or 
diester, and 
(B) either polymerized .alpha.-olefins, or a copolymer of dialkyl fumarate 
with either vinyl acetate or alkyl methacrylate. 
British patent BG No. 1,469,016 mentions a synergic mixture consisting of: 
(A) a polyethylene or chlorinated polyethylene or copolymer of ethylene 
with an unsaturated mono or diester, an .alpha.-olefin or vinyl chloride, 
(B) a polymer or copolymer derivating from at least one of the alkyl 
diesters of unsaturated carboxylic diacids and .alpha.-olefins. 
Japanese patent JP No. 54,086,505 teaches a composition having a synergic 
effect, prepared from: 
(A) a polyethylene, a chlorinated polyethylene, a copolymer of 
ethylene/vinyl acetate or a compound of alkyl aromatic type; and 
(B) a copolymer obtained from a N,N'-dialkyl maleamide derivative and an 
.alpha.-olefin of 8-30 carbon atoms. 
However, none of these compositions is able to confer to the oil middle 
distillates, and particularly to gas-oils and fuel-oils, satisfactory 
properties at cold temperatures, as a whole. 
On the other hand, the applicants have previously described certain 
additives which, by a mechanism not yet clear, may reduce the temperature 
of formation of the first paraffin crystals (particularly in the French 
patent application FR No. 2,528,066, filed on June 4, 1982). Briefly 
stated, this additive may be described as the product obtained by 
reaction, of a terpolymer comprising: 
(a) at least one linear .alpha.-olefin 
(b) at least one unsaturated .alpha.,.beta.-dicarboxylic compound, such as 
diacid, light alkyl diester or anhydride, and 
(c) at least one alkyl ester of an unsaturated monocarboxylic acid; 
with at least one compound with a primary amine group complying with one of 
the general formulas: 
EQU R--Z[(CH.sub.2).sub.n NH].sub.m H (I) 
and 
EQU HO--CH.sub.2 --R"--NH.sub.2 (II) 
wherein R is a saturated aliphatic monovalent radical of 1-30 carbon atoms, 
Z is selected from --NH--, or --NR'-- groups, wherein R' is a saturated 
aliphatic monovalent radical of 1-30 carbon atoms, and the oxygen atom 
--O--, n is an integer from 2 to 4, m is zero or an integer from 1 to 4; 
and R" is a saturated aliphatic divalent radical of 1-18 carbon atoms. 
These additives, when added to gas-oil cuts, for example at concentrations 
of about 0.1% by weight, have shown a favorable action, mainly on the 
cloud point thereof, but also on their filterability limit temperature as 
well as on their pour point temperature. 
SUMMARY OF THE INVENTION 
It has now been discovered that it was possible to more clearly improve the 
cold filterability properties of oil middle distillates, having 
distillation ranges, according to ASTM-D-1160 distillation Standard, 
between initial temperatures of 160.degree. to 235.degree. C. and final 
temperatures of 355.degree. to 440.degree. C., (based on atmospheric 
pressure) by using certain combinations of products which are described 
hereinafter. 
Generally, the additives compositions considered in this invention, may be 
defined as mainly comprising: 
a constituent (A) which is at least one ethylene polymer, and 
a constituent (B) which is at least one polymeric compound which may be 
defined as resulting from the condensation of at least one compound with a 
primary amine group such as hereinafter defined, with a copolymer 
comprising: 
(a) recurrent units from at least one linear .alpha.-olefin, 
(b) recurrent units derived from at least one unsaturated 
.alpha.,.beta.-dicarboxylic compound, such as a diacid, light alkyl 
diester or anhydride; and 
(c) recurrent unit from at least one alkyl ester of an unsaturated 
aliphatic monocarboxylic acid or from at least one vinyl ester of a 
saturated aliphatic monocarboxylic acid. 
The clear improvement in cold filterability properties of wide or narrow 
gas-oil cuts to which were added the additive combinations according to 
the invention, is a quite unexpected result when considering that singly 
each of the constituents has only a very slight effect on the 
filterability properties. 
More particularly, constituent (A) of the additive compositions of the 
invention may be at least one ethylene polymer having a number average 
molecular weight from 500 to 15,000 preferably from 1,000 to 5,000, and a 
structure corresponding to the general formula: 
##STR1## 
wherein: m and n are integers from 1 to 20, the sum (m+n) ranging for 
example from about 9 to 34, and p is an integer from 3 to 30. 
Constituent (B) has preferably a number average molecular weight from 1 000 
to 10 000. 
The copolymers used in the formation of constituent (B) comprise more 
particularly a proportion from 15 to 40% by mole of recurrent units 
derived from .alpha.-olefins, 20-70% by mole of recurrent units derived 
from unsaturated .alpha.,.beta.-dicarboxylic compounds and 15-40% by mole 
of recurrent units derived from alkyl esters of unsaturated monocarboxylic 
acids. 
The linear .alpha.-olefins comprised in the composition of the polymers 
contain for example 16-30 carbon atoms. Mixtures of linear .alpha.-olefins 
of 20-24 carbon atoms, of 24-28 carbon atoms or cuts of about 20% by 
weight of .alpha.-olefins of 28 carbon atoms or less and about 80% by 
weight of .alpha.-olefins of 30 carbon atoms or more, are advantageously 
used. 
The unsaturated .alpha.,.beta.-dicarboxylic compounds comprised in the 
composition of the copolymer are more particularly dicarboxylic acids such 
as maleic acid or alkylmaleic acids, for example methylmaleic (or 
citraconic) acid. 
These compounds may also be alkyl diesters of said dicarboxylic acids, 
particularly methyl, ethyl or propyl diesters, or the anhydrides 
corresponding to said dicarboxylic acids. Anhydrides are preferred, more 
particularly maleic anhydride. 
Alkyl esters of unsaturated monocarboxylic acids are more particularly 
alkyl acrylates and methacrylates, alkyl being in C.sub.4-30 for example, 
butyl, ethylhexyl, decyl, dodecyl, hexadecyl, octadecyl and eicosyl 
acrylates. Acrylates and methacrylates of industrial alcohol cuts 
containing, as an average, 12 carbon atoms (lauryl acrylate and 
methacrylate) or 18 carbon atoms (stearyl acrylate and methacrylate) and 
heavier alcohol cuts, of high content of alcohols having 20-22 carbon 
atoms, may also be mentioned. 
Vinyl esters of saturated aliphatic monocarboxylic acids are more 
particularly those vinyl esters of monocarboxylic acids having 2 to 22 
carbon atoms, such for example as vinyl acetate, propionate, butyrate or 
vinyl stearate. 
The compound with the primary amine group which is condensed with the 
above-described copolymers to form constituent (B) of the additives 
compositions according to the invention, may comply with one of the two 
following general formulas: 
EQU R--Z[(CH.sub.2).sub.n NH].sub.m H (I) 
EQU HO--CH.sub.2 --R"--NH.sub.2 (II) 
In formula (I), 
R is a saturated aliphatic monovalent radical containing 1 to 30 carbon 
atoms; 
Z may be either an oxygen atom or a divalent --NH-- or --NR'-- group, R' 
being a monovalent aliphatic radical, preferably linear, comprising 1 to 
30 carbon atoms and preferentially 12 to 24 carbon atoms, n is an integer 
from 2 to 4, and m is an integer from 1 to 4, or may also be zero, when Z 
is NH. 
The compounds of formula (I), may consist of primary amines of the formula 
R--NH.sub.2 (then, in formula (I), Z is the --NH-- group, and m is zero). 
Preferably, radical R is linear and contains 12 to 24 carbon atoms. 
Specific examples of said amines are: dodecylamine, tetradecylamine, 
hexadecylamine, octadecylamine, eicosylamine and docosylamine. 
Compounds of formula (I) may also consist of polyamines derived from 
saturated aliphatic amines complying with the formula: 
EQU R--NH[(CH.sub.2).sub.n NH].sub.m H 
which corresponds to the general formula (I) wherein Z is the --NH-- group; 
m may range from 1 to 4 and n from 2 to 4, with a preferred value of 3. 
Preferably, radical R is linear and contains 12-24 carbon atoms Specific 
compounds are: N-dodecyl-1,3-diamino propane, N-tetradecyl 1,3-diamino 
propane. N-hexadecyl 1,3-diamino propane, N-octadecyl 1,3-diamino propane, 
N-eicosyl 1,3-diamino propane, N-docosyl 1,3-diamino propane, 
N-hexadecyldipropylene triamine, N-octadecyl dipropylene triamine, 
N-eicosyldipropylene triamine and N-docosyldipropylene triamine. 
The compounds of formula (I) may also consist of polyamines complying with 
the formula: 
##STR2## 
corresponding to the general formula (I) where Z represents --NR'-- and 
where R and R', identical or different, are each an alkyl radical having 1 
to 24 and preferably 8 to 24 carbon atoms, R and R' having together 
preferably from 16 to 32 carbon atoms; the value of n is from 2 to 4 and 
the value of m from 1 to 4. 
Examples of specific compounds are: N,N-diethyl 1,2-diamino ethane, 
N,N-diisopropyl 1,2-diamino ethane, N,N-dibutyl 1,2-diamino ethane, 
N,N-diethyl 1,4-diamino butane, N,N-dimethyl 1,3-diamino propane, 
N,N-diethyl 1,3-diamino propane, N,N-dioctyl 1,3-diamino propane, 
N,N-didecyl 1,3-diamino propane, N,N-didodecyl 1,3-diamino propane, 
N,N-ditetradecyl 1,3-diamino propane, N,N-dihexadecyl 1,3-diamino propane, 
N,N-dioctadecyl 1,3-diamino propane, N,N-diodecyldipropylenetriamine, 
N,N-ditetradecyldipropylenetriamine, N,N-dihexadecyldipropylenetriamine 
and N,N-dioctadecyldipropylenetriamine. 
Finally, the compounds of formula (I) may consist of ether-amines, more 
particularly those complying with the formula: 
EQU R--O[(CH.sub.2).sub.n NH].sub.m H 
which corresponds to the general formula (I) wherein Z is an oxygen atom; 
preferably radical R is linear and contains 12-24 carbon atoms, m is an 
integer from 1 to 4, and n an integer from 2 to 4, preferably 2 or 3. 
Specific examples of ether-amines are: 2-methoxy ethylamine, 3-methoxy 
propylamine, 4-methoxy butylamine, 3-ethoxy propylamine, 3-octyloxy 
propylamine, 3-decyloxy propylamine, 3-hexadecyloxy propylamine, 
3-eicosyloxy propylamine, 3-docosyloxy propylamine, N-(3-octyloxy 
propyl)1,3-diamino propane, N-(3-decyloxy propyl) 1,3-diamino propane, 
(2,4,6-trimethyl decyl)3-oxy propylamine and N-[2,4,6-trimethyl decyl) 
3-oxypropyl]1,3-diamino propane. 
The compound with primary amine group involved in the manufacture of 
constituent (B) of the additives compositions according to the invention 
may also consist of an aminoalcohol of formula (II): 
EQU HO--CH.sub.2 --R"--NH.sub.2 (II) 
wherein R" is a linear or branched, saturated divalent aliphatic radical, 
preferably linear, containing 1 to 18 carbon atoms. 
Specific examples are: monoethanolamine, 1-amino 3-propanol, 1-amino 
4-butanol, 1-amino 5-pentanol, 1-amino 6-hexanol, 1-amino 7-heptanol, 
1-amino 8-octanol, 1-amino 10-decanol, 1-amino 11-undecanol, 1-amino 
13-tridecanol, 1-amino 14-tetradecanol, 1-amino 16-hexadecanol, 2-amino 
2-methyl 1-propanol, 2-amino 1-butanol and 2-amino 1-pentanol. 
It must be understood that constituent (B) may consist of one or more 
compounds complying with formula (I) and/or one or more compounds 
complying with formula (II). 
The preparation of constituents (B) of the additive compositions according 
to the invention is generally performed in two steps: first the 
preparation of terpolymers, followed with the condensation thereon of the 
compound of formula (I) and/or (II). 
The terpolymers may be prepared, in a first step, according to conventional 
methods of radical polymerization, for example in the presence of an 
initiator of the azobiisobutyronitrile or peroxide type, in solution in a 
hydrocarbon solvent, such for example as: cyclohexane, isooctane, 
dodecane, benzene, toluene, xylene, diisopropylbenzene, tetrahydrofuran or 
dioxane. 
The use of hydrocarbon cuts of relatively high boiling point, such as 
kerosene or a gas-oil, is advantageous. The amount of solvent will 
generally be such that the concentration by weight of dry material ranges 
from 25 to 70% and is preferably about 60%. 
The copolymerization reaction is the presence of the radical initiator is 
conducted at a temperature of 70.degree.-200.degree. C., preferably 
80.degree.-130.degree. C. In the operating conditions, the reaction may 
last from 2 to 14 hours. A copolymer solution is obtained as viscous 
liquid a light yellow color. 
Then, in a second step, the compound of formula (I) or (II) is condensed on 
the copolymer formed in the first step, according to any usual method. 
Generally, the compound of formula (I) or (II) is added to the copolymer 
solution, obtained as above described, in a molar proportion corresponding 
substantially to the proportion of diacid, diester, or unsaturated 
anhydride involved in the manufacture of the copolymer. This proportion 
may, for example, range from 0.9 to 1.1 mole of compound (I) or (II) per 
mole of dicarboxylic compound. It is also possible to use compound (I) or 
(II) in a much lower proportion, which may be as low as, for example, 0.5 
mole per mole of dicarboxylic compound involved in the copolymer. 
The reaction is conducted by heating the mixture at a temperature from 
75.degree. to 130.degree. C., preferably from 80.degree. to 100.degree. 
C., the reaction time being from about 1 to 6 hours, generally 2 hours 
being sufficient. 
The reaction of products of formula (I) or (II) on recurrent units (b) of 
the copolymer, gives rise to imides (succinimides) groups, this reaction 
being accompanied with the formation of water or alcohol, depending on the 
nature of the dicarboxylic functions of (b) (diacid, anhydride or 
diester). The volatile products formed may be, if so desired, driven away 
outside the reaction mixture by means of an inert gas such, for example, 
as nitrogen or by azeotropic distillation with the selected solvent. 
Another particular mode of synthesis of constituents (B) of the additive 
compositions according to the invention may consist, sometimes, in the 
radical copolymerization of one or more alkyl esters of unsaturated 
monocarboxylic acids or vinyl ester of saturated monocarboxlyic acid, with 
a mixture of .alpha.-olefins and N-substituted maleimides, the latter 
being obtained by previously reacting compounds of formula (I) or (II) 
with maleic anhydride or one of its above-mentioned derivatives. 
As above-mentioned, the additive compositions of the invention, comprising 
at least one constituent (A) and at least one constituent (B) such as 
precedingly defined, are used particularly to improve the cold 
filterability properties of oil middle distillates with respect to which 
each of constituents (A) and (B), considered separately, has but a very 
reduced effect. It thus seems that each of the constituents (A) and (B) 
has an effective synergism action on the properties of the other, the 
mechanism of which is not very clear. 
Generally, this action appears substantial when the ratio between the 
amounts by weight of constituents (A) and (B) ranges from 1/20 to 20/1 
and, preferentially, from 1/5 to 5/1. 
In order to obtain a clear improvement in the cold filterability properties 
of the gas-oil cuts considered in this invention, the combinations of 
additives (A) and (B) are generally added to these gas-oil cuts at total 
concentrations by weight ranging from 20 to 2000 ppm and, more 
particularly from 50 to 500 ppm. In the gas-oil formulations according to 
the invention, it is possible to add constituents (A) and (B) directly to 
the gas-oil by a mere mixing operation. 
However, it is often advantageous to introduce them as previously prepared 
"mother solutions": these mother-solutions may be either two separate 
solutions in the same solvent or in two different solvents, or a solution 
of the two constituents. The one or more solvents may consist for example 
of aromatic solvents such for example as toluene, xylenes, 
di-isopropylbenzene or of an oil cut of aromatic type within the desired 
distillation range. 
The "mother-solutions" may contain for example 20-60% by weight of 
additives. 
Moreover, it is observed, as a remarkable feature, that the additive 
compositions of the invention, which are efficient, in contrast to the 
conventional additives, in wide cuts, i.e. those having for example a 
distillation range from 160.degree. to 370.degree. C. and more, on the one 
hand are still efficient when used in a "narrow" cut, having for example a 
distillation range from 225.degree. to 360.degree. C. and more, i.e. a 
wide cut from which the light (kerosene) fraction has been removed, and, 
on the other hand, simultaneously inhibit the settling of n-paraffins in 
doped gas-oils at rest, although the considered n-paraffins are the 
heavier n-paraffins of the crude distillable fraction. 
This result is the more surprising as it is the light fraction which has a 
very favorable influence on the filterability temperature and on the 
parrafins solvation. 
The compositions of the invention hence provide for a considerable 
improvement in the cold filterability properties of oil middle 
distillates, whereby gas-oil and fuels from distillates cuts of higher 
final boiling point can be used, which represents an obvious economical 
advantage.

EXAMPLES 
The following examples illustrate the invention but must not be considered 
in any way as limiting the scope thereof. 
In the examples, the gas-oil cuts are those specified in Table I; they are 
characterized by the ASTM-D-1160 distillation Standard; their density is 
also indicated in Table I. One of them is a "narrow", one other a wide cut 
and the others are intermediary cuts. They are designed by references G1, 
. . . G6. 
Concentrations of components (A) and (B) of the additives are in 
proportions by weight of pure products expressed in parts per million 
(ppm), being it understood that the compositions may be used in dilute 
state. 
Determinations of filterability limit temperature (F.L.T.) are conducted 
according to the European standard EN 116 of August 1981. 
TABLE I 
______________________________________ 
DISTALLATION ASTM D 1160 
distilled 
DENSITY 
GAS OIL Initial point 
final point 
volume at 15.degree. C. in 
CUT No in .degree.C. 
in .degree.C. 
at 350.degree. C., % 
kg/l 
______________________________________ 
G.sub.1 184 385 85 0.8527 
G.sub.2 205 375 90 0.8486 
G.sub.3 225 384 82 0.8502 
(narrow 
cut) 
G.sub.4 184 368 93 0.8439 
G.sub.5 205 415 83 0.8507 
G.sub.6 160 378 90 0.8380 
(wide cut) 
______________________________________ 
EXAMPLE 1 
In this example, additives compositions have been used in four gas-oil cuts 
G.sub.1, G.sub.2, G.sub.3 and G.sub.4. 
As constituents (A), two ethylene polymers A.sub.1 and A.sub.2 have been 
used, which have the following characteristics: 
______________________________________ 
A.sub.1 
A.sub.2 
______________________________________ 
Average molecular weight 
2725 3000 
Branching rate 9 11 
(number of CH.sub.3 per 100 carbon atoms) 
______________________________________ 
Constituent (B) was a condensation product of a terpolymer with a fatty 
amine, which will be called B.sub.1. The terpolymer is one molar 
equivalent of a C.sub.20-24 .alpha.-olefins cut of M.sub.n =295 
comprising, by moles, about 1% of C.sub.18 olefin, 49% of C.sub.20 
olefins, 42% of C.sub.22 olefins and 8% of C.sub.24 olefins, of one molar 
equivalent of an alcohols methacrylate cut whose composition is the 
following by weight: 2% of C.sub.14, 15% of C.sub.16, 30% of C.sub.18, 14% 
of C.sub.20, and 3% of C.sub.22, called stearyl methacrylate (SMA) of 
M.sub.n =326, and of one mole of maleic anhydride, this terpolymer being 
prepared by stirring and heating at 130.degree. C. for 4 hours, in 250 ml 
of a solvent consisting of an oil cut distilling between 120.degree. and 
250.degree. C. and with a continuous introduction, during 4 hours, of 
about 0.003 mole per double bond of benzoyl peroxide diluted with a small 
amount of solvent. 
The number average molecular weight of the terpolymer is 2470. 
The fatty amine is a cut of primary amines whose alkyl chains comprise, in 
approximate molar proportions: 1% of C.sub.14, 28% of C.sub.16 and 71% of 
C.sub.18. It is used in a proportion of one molar equivalent. The 
condensation of the amine on the terpolymer is performed by heating at 
90.degree. C. for 2 hours. The obtained solution, adjusted to 50% by 
weight of dry material, forms the mother solution of B.sub.1. 
The filterability limit temperature of each of the gas-oil cuts without 
additives or with the additives indicated in Table II hereinafter, have 
been determined (the F.L.T. are in .degree.C.). 
TABLE II 
______________________________________ 
Test gas-oil cut G.sub.1 cut 
G.sub.2 cut 
G.sub.3 cut 
G.sub.4 cut 
______________________________________ 
1 a without additive 
+2 +1 +7 -1 
1 b 100 ppm of A.sub.1 
-3 -3 0 -4 
1 c 100 ppm of A.sub.2 
-2 -3 +1 -6 
1 d 100 ppm of B.sub.1 
+1 0 +3 0 
1 e 50 ppm of A.sub.1 + 
-8 -10 -7 -17 
50 ppm of B.sub.1 
1 f 50 ppm of A.sub.2 + 
-7 -12 -6 -15 
50 ppm of B.sub.1 
______________________________________ 
These values of filterability limit temperature for each of the treated 
gas-oil cuts show that the decreases obtained with mixtures A.sub.1 
+B.sub.1 according to the invention are very substantially higher than the 
values to be expected (synergism effect). 
EXAMPLE 2 
In this example, the proportions of the mixture of the two constituents 
A.sub.1 and B.sub.1 described in example 1 are varied. The gas-oil is the 
C.sub.4 cut whose characteristics are given in Table I. 
The total concentration of additives A.sub.1 +B.sub.1 in the gas-oil is 100 
ppm. 
Table III gives the determined F.L.T. values for the various tests; also 
the values obtained for the C.sub.4 gas-oil cut of example 1 are reported 
(tests 2a, 2b, 2g, 2d, corresponding to tests 1a, 1b, 1d and 1e, 
respectively). 
TABLE III 
______________________________________ 
Constituent Constituent 
Test A.sub.1 (ppm) B.sub.1 (ppm) 
FLT (.degree.C.) 
______________________________________ 
2 a 0 0 -1 
2 b 100 0 -4 
2 c 70 30 -18 
2 d 50 50 -17 
2 e 40 60 -15 
2 f 25 75 -10 
2 g 0 100 0 
______________________________________ 
The synergic effect of constituents A.sub.1 and B.sub.1 appear obviously 
from these results. 
EXAMPLE 3 
The gas-oil G.sub.1 described in Table I is used in this example. The 
additive is a mixture of compound A.sub.2 and compound B.sub.1, such as 
described in example 1, used in a proportion by weight A.sub.2 /B.sub.1 
=75/25. 
In this example, the total additive concentration is varied. Table IV 
indicates the results obtained for the FLT. 
TABLE IV 
______________________________________ 
Tests 3a 3b 3c 
______________________________________ 
Additives concentra- 
0 100 200 
tion (ppm) 
F.L.T. (.degree.C.) 
+2 -15 -18 
______________________________________ 
EXAMPLE 4 
By way of comparison, three gas-oils G.sub.3 (narrow cut), G.sub.4 and 
G.sub.5 have been treated with three additives 1, 2 and 3 at a 
concentration of 50 ppm. 
Additives 1 and 2 correspond to conventional additives of the trade. 
Additive 3 corresponds to the composition of the additive according to the 
invention, as described in example 3. 
The FLT values are given in the following table V (in .degree.C.) 
TABLE V 
______________________________________ 
Test Additives G.sub.3 gas-oil 
G.sub.4 gas oil 
G.sub.5 gas oil 
______________________________________ 
4 a without +7 -1 +1 
4 b 1 0 -8 -4 
4 c 2 +2 -8 -8 
4 d 3 -2 -10 -7 
______________________________________ 
As a whole, the results are better with additive 3 according to the 
invention than with additives 1 and 2 of the trade. 
EXAMPLE 5 
Three test tubes of 100 cc are filled with the cut G.sub.5. 
In the first test tube, no additive is introduced. In the second test tube 
100 ppm of the conventional additive of the trade are introduced. 
In the third test tube, 100 ppm of the additive composition as described in 
example 3 are introduced. 
The three test tubes are tightly sealed and maintained at rest in cold 
storage at -10.degree. C. for one week. After one week, the settling rate 
of the precipitated paraffins is that given in the following table: 
TABLE VI 
______________________________________ 
Test tube no 2 Test tube no 3 
Test tube no 1 
(conventional additive 
(+ additive of the 
(without additive 
of the trade) invention) 
Test 5 a Test 5 b Test 5 c 
______________________________________ 
50% 95% 15% 
______________________________________ 
It appears that the action of the conventional additive speeds up the 
settling of the paraffins of the considered gas-oil as compared with the 
same non-doped gas-oil, whereas the additive compositon according to the 
invention delays it substantially. 
EXAMPLES 6 TO 11 
In these examples, the nature of constituent (B) used in admixture with 
constituent A.sub.1, described in example 1, is varied. 
Table VII indicates the selective compositions for constituents (B). 
TABLE VII 
______________________________________ 
unsaturated ester Product 
.alpha.- 
.alpha., .beta.-dicar- 
of un- condensed 
Ref olefins boxylic saturated on the terpo- 
(B) cut compound acid --M.sub.n 
lymer 
______________________________________ 
B.sub.2 
C.sub.30.sup.+ 
Maleic anhyd. 
SMA 2820 butylamine 
B.sub.3 
C.sub.24-28 
" EHA 2540 ether-amine 
B.sub.4 
C.sub.24-28 
" EHA 3200 Primary and 
secondary diamine 
B.sub.5 
C.sub.24-28 
" EHA 4450 ethanolamine 
B.sub.6 
C.sub.15-20 
" SMA 4300 primary and 
tertiary diamine 
______________________________________ 
The terpolymer is formed of a molar equivalent of each of the three 
unsaturated compounds: .alpha.-olefins, maleic anhydride, ester of 
unsaturated acid. On this terpolymer is condensed a molar equivalent of 
the compound with primary amine group. 
The .alpha.-olefins cuts may be defined by their average molecular weight 
and their content in their different constituents: 
the C.sub.30 +cut, of average molecular weight 420, comprises approximately 
22% of C.sub.28 and lower .alpha.-olefins, 78% of C.sub.30 and higher 
.alpha.-olefins. 
the C.sub.24-28 cut, of average molecular weight 364, comprises 1% of 
C.sub.22 .alpha.-olefins, 30% of C.sub.24 .alpha.-olefins, 39% of C.sub.26 
.alpha.-olefins, 20% of C.sub.28 .alpha.-olefins, 10% of C.sub.30 and 
higher .alpha.-olefins. 
the C.sub.15 -C.sub.20 cut, of average molecular weight 244, contains even 
and odd .alpha.-olefins, in proportion of 1% of C.sub.14, 17% of C.sub.15, 
18% of C.sub.16, 17% of C.sub.17, 17% of C.sub.18, 15% of C.sub.19, 12% 
and C.sub.20 and 3% of C.sub.21. 
The esters of unsaturated acids are methacrylates or acrylates: the SMA cut 
has been described in example 1. 
EHA designates 2-ethyl hexyl acrylate. 
The compounds with primary amine group are: 
for constituent B.sub.3, the N[(2,4,6-trimethyl 
decyl)3-oxy-1propyl)]1,3-diamino propane. 
for constituent B.sub.4, the N-alkyl 1,3 diamino propane whose alkyl chains 
contain about 1% of C.sub.14, 5% of C.sub.16, 42% of C.sub.18, 12% of 
C.sub.20, 40% of C.sub.22. 
for constituent B.sub.6, the N,N-didodecyl 1,3 diamino propane. 
The manufacture of constituents B has been described in example 1. 
Constituents A and B have been tested alone and as mixtures in three 
proportions 75/25, 50/50, 25/75, in the three gas-oil cuts G.sub.1, 
G.sub.4, G.sub.6 (wide). 
The measured filterability limit temperatures are given in table VIII. 
TABLE VIII 
__________________________________________________________________________ 
No No FLT (.degree.C.) 
EXAMPLE 
TEST 
COMPOSITION G.sub.1 
G.sub.4 
G.sub.6 
__________________________________________________________________________ 
6 6a without additive 
+2 -1 +2 
6b 100 
ppm 
A.sub.1 -3 -5 -5 
6c 100 
ppm 
B.sub.2 -1 -2 -3 
6d 100 
ppm 
B.sub.3 0 -2 -3 
6e 100 
ppm 
B.sub.4 0 -3 -4 
6f 100 
ppm 
B.sub.5 0 -1 -3 
6g 100 
ppm 
B.sub.6 -1 -3 -4 
7 7a 75 ppm 
A.sub.1 + 25 ppm 
B.sub.2 
-6 -10 -11 
7b 50 ppm 
A.sub.1 + 50 ppm 
B.sub.2 
-6 -10 -10 
7c 25 ppm 
A.sub.1 + 75 ppm 
B.sub.2 
-4 -7 -6 
8 8a 75 ppm 
A.sub.1 + 25 ppm 
B.sub.3 
- 6 -7 -9 
8b 50 ppm 
A.sub.1 + 50 ppm 
B.sub.3 
-5 -7 -8 
8c 25 ppm 
A.sub.1 + 75 ppm 
B.sub.3 
-3 -5 -5 
9 9a 75 ppm 
A.sub.1 + 25 ppm 
B.sub.4 
-5 -8 -8 
9b 50 ppm 
A.sub.1 + 50 ppm 
B.sub.4 
-5 -8 -7 
9c 25 ppm 
A.sub.1 + 75 ppm 
B.sub.4 
-3 -6 -5 
10 10a 75 ppm 
A.sub.1 + 25 ppm 
B.sub.5 
-6 -9 -10 
10b 50 ppm 
A.sub.1 + 50 ppm 
B.sub.5 
-6 -8 -9 
10c 25 ppm 
A.sub.1 + 75 ppm 
B.sub.5 
-4 -5 -6 
11 11a 75 ppm 
A.sub.1 + 25 ppm 
B.sub.6 
-6 -13 -13 
11b 50 ppm 
A.sub.1 + 50 ppm 
B.sub.6 
-5 -11 -11 
11c 25 ppm 
A.sub.1 + 75 ppm 
B.sub.6 
-3 -7 -8 
__________________________________________________________________________ 
All the values of the filterability limit temperatures show a more or less 
substantial synergism effect according to the nature of constituent (B). 
It appears that the best results correspond to a proportion of ethylene 
polymer (A.sub.1) closer to 75% than to 50%.