US3762888A

US3762888A - Fuel oil composition containing oil soluble pour depressant polymer and auxiliary flow improving compound

Info

Publication number: US3762888A
Application number: US00090115A
Authority: US
Inventors: A Kober; A Rossi
Original assignee: Exxon Research and Engineering Co
Current assignee: ExxonMobil Technology and Engineering Co
Priority date: 1970-11-16
Filing date: 1970-11-16
Publication date: 1973-10-02
Anticipated expiration: 1990-10-02
Also published as: CA965948A; FR2114718A5; IT940603B; DE2156425C2; JPS5419406B1; GB1364883A; DE2156425A1

Abstract

Cold flow properties of fuel oils are improved by addition thereto of certain oil-soluble, pour point depressant polymers together with non-nitrogen containing, oil-soluble, auxiliary, flow improving compounds.

Description

United States Patent 11 1 Kober et a1.

Oct. 2, 1973 FUEL OIL COMPOSITION CONTAINING OIL-SOLUBLE POUR DEPRESSANT POLYMER AND AUXILIARY FLOW-IMPROVING COMPOUND Appl. No.: 90,115

US. Cl 44/62, 44/66, 44/70, 44/79, 44/80 Int. Cl. C101 1/18, C101 l/2O Field of Search 44/62, 66, 70, 79, 44/80 References Cited UNITED STATES PATENTS 11/1971 Hollyday et a1 44/62 7/1945 Lieber et a1. 44/62 10/1952 Lippincott et a1. 44/62 3,598,552 8/1971 Cohen et a1. 44/62 FOREIGN PATENTS OR APPLICATIONS 676,875 12/1963 Canada 44/62 993,744 6/1965 Great Britain 74/62 933,057 7/1963 Great Britain 44/62 Primary Examiner-Danie1 E. Wyman Assistant Examiner-W. J. Shine Att0rneyPear1man & Schlager and Carl G. Seutter [57] ABSTRACT Cold flow properties of fuel oils are improved by addition thereto of certain oil-soluble, pour point depressant polymers together with non-nitrogen containing, oil-soluble, auxiliary, flow improving compounds.

23 Claims, N0 Drawings FUEL OIL COMPOSITION CONTAINING OIL-SOLUBLE POUR DEPRESSANT POLYMER AND AUXILIARY FLOW-IMPROVING COMPOUND BACKGROUND OF THE INVENTION DESCRIPTION OF THE PRIORART Kerosene, which acts as a solvent for n-paraffin wax, has traditionally been a component of middle distillate" fuel oils. Recently, with the increased demand for kerosens for use in jet fuels, the amount of kerosene used inmiddle distillate fuel oils has decreased. This, in turn, has frequently required the addition of wax crystal modifiers, e.g.;, pour point depressant additives, to the fuel oil to make up for the lackof kerosene.

The more effective of these distillate oil pourdepressants are copolymers of ethylene with various other monomers, e.g. copolymers of ethylene and vinyl esters of lower fatty acids such as vinyl acetate (U.S. Pat. No. 3,048,479); copolymers of ethylene and alkyl acrylate (Canadian Pat. No. 676,985); terpolymers of ethylene with vinyl esters and alkyl fumarates (U.S. Pat. Nos. 3,304,261 and 3,341,309); polymers of ethylene with other lower olefins, or homopolymers of ethylene (British Pat. Nos. 848,777 and 993,744); chlorinated polyethylene (Belgium Pat. No. 707,371 and U.S. Pat. No. 3,337,313); etc.

However, in general, these ethylene backbone pour point depressants, while very effective in lowering the pour point of distillate oil, sometimes have little or no effect on wax crystal size. Wax crystals having large particle sizes ranging from 1 millimeter up to an inch in their larger dimensions may therefore be present in these fuels. These large particles tend to be filtered out by the screens'and other filter equipment normally used on delivery trucks and fuel oil storage systems, with a resulting-plugging of these screens and filters even though the temperature of the oil is substantially above its pour point.

Prior art flow improvers also include the use of naturally occurring waxes or nitrogen compounds. Typical of prior art flow improvers are those shown in U.S. Pat. No. 3,250,599 and U.S. Pat. No. 2,615,799 and U.S. Pat. No. 2,917,375 including mixtures of ethylene-vinyl acetate copolymers or of polymers of esters of acrylates or methacrylates together with microcrystalline waxes or normal paraffins. U.S. Pat. No. 3,444,082 discloses the use of certain nitrogen-containing compounds as does British Pat. No. 1,140,171. Other prior patents'of interest include U.S. Pat. No. 3,166,387, British Pat. No. 1,154,966, etc. It has now been found that materials other than nitrogen-containing materials or naturally occurring compositions can be used to improve the performance of flow improvers.

SUMMARY OF THE INVENTION In accordance with certain of its aspects, the novel fuel oil composition of this invention comprises:

a. a major portion of a middle distillate fuel boiling in the range of 250-750F., and a minor portion of a flow-improving system containing b. asafirst component aneoil-soluble; pour. point de- M). .1 0f

pressant polymer of 1 molecular weight 500-50,000 selected. from the. groupisconsisting ofz an ethylene polymer,

a hydrogenated olefin polymer,

a C olefin polymer,

a halogenated. ethylene polymer, and

a polymer of 3-40 molesrof ethyleneand one-moleof,

a copolymerizable comonomer; selected a from r the group. consisting of i. a. vinyl ester. of a. C perferablyr C monocarboxylic. acid, ii. an ethylenically unsaturatedtesterr /X: C H2 0 wherein X is H, halogen, or alkyl, Y ishalogeniorr -COOR and.R is C ,perferably;C alkyl orlaryl,

iii. an ethylenicallyunsaturated.compound.

wherein R is H or lower alkyl andR is. H orC preferably C t alkyl; and.

iv. aC preferably C olefinhydrocarbon;

c. as a second component a non.-nitrogen-containing, oil-soluble auxiliary flow-improving compound containing at least one. straight-chain (CH polymethylene segment where n is-lO-30. and. a. bulky substituent on said polymethylene: segment selected. from the group consisting of (i) non-polarhydrocarbon moieties substantially free of saturated cyclic hydrocarbons, and (ii) polar moieties containing halogen,.oxy;. gen, sulfur, or phosphorous.

The middle distillate fuel oils which may betreated by the technique of this novel invention may commonly have a fluidity, prior to treatment, of 0-20 percent, say. 0-10 percent typically 5 percent as measuredbyt a standard test herein designated the Enjay Programmed Flue idity Test. This test may be carried out in an hour-glass.- shaped cylindrical device having upper and lower chambers separated by a partition defining a capillary orifice. 40 ml. of oil are poured into the lowerchamber, and the device containing the oil is thenichilledxfroma temperature of 10F. above its ASTM cloud point atu a rate of 4F. per hour, to a temperature of 10F. below. its cloud point. The deviceis inverted, allowingzthenowr cloudy oil to flow by gravity into the empty lower chamber. The volume percent of the oil passing, throughthe orifice in three minutesis note.d..lfthe wax is in large crystals, it of course blocks the orifice and slows the oil flow. Small crystals,.on the other hand; give good flow.

Another test which may be used to determine the: flow properties of a middle distillate is the ColdLFilter' Plugging Point Test CFPPT). Thistest isicarried out by the proceduredescribed in detailin Llournaltof the lnstituteof Petroleum, Volume 52,.Number5130,..lune 1966, pp. 173-1 85. In brief, the Cold Filter Plugging Point Test is carried out with a 45 ml. sampleof theioil to be tested which is cooled in a bath maintained at about -30F. Every 2 drop in temperature, starting from 4F. above the cloud point, the oil is tested with a test device consisting of a pipette to whose lower end is attached an inverted funnel. Stretched across the mouth of the funnel is a 350 mesh screen having-an area of about 0.45 sqaure inch. A vacuum of about 7 of water is applied to the upper end of the pipette by means of a vacuum line while the screen is immersed in the oil sample. Due to the vacuum, oil is drawn across the screen up into the pipette to a mark indicating 20 ml. of oil. The test is repeated with each two degrees drop in temperature until the oil fails to fill the pipette to the aforesaid mark due to clogging of the screen with wax crystals. The results of the test are reported as the operability limit or cold filter plugging point, which is the temperature in F. at which the oil fails to fill the pipette in prescribed time.

The preferred fuel oil compositions which may be treated by the process of this invention may include middle distillate fuels having a boliing point in the range of 250-750F. Commonly, the 10-90 percent boiling range of the middle distillate will fall within the range of 250-750F., eg, 300-700F. Typical of these compositions may be those commonly designated middle dsitillate fuel oil.

The oil-soluble, pour point depressant which may be the first component of the composition or system used in practice of this invention, typically present, per 100 parts of oil, in amount of 0.001 0.5 parts, preferably 0.005 0.3 parts, say 0.02, may be selected from the group consisting of:

an ethylene polymer,

a hydrogenated olefin polymer,

a C olefin polymer,

a halogenated ethylene polymer, and

a polymer of 3-40 moles of ethylene and one mole of a copolymerizable comonomer selected from the group consisting of i. a vinyl ester of monocarboxylic acid,

ii. an ethylenically unsaturated ester a C,. preferably C wherein X is H, halogen, or alkyl, Y is halogen or COOR and R is C preferably C alkyl or aryl,

iii. an ethylenically unsaturated compound R-CCOOR" R-ii-OOOR wherein R is H or lower alkyl and R" is H or C preferably C alkyl; and

iv. a C preferably C olefin hydrocarbon.

When the first component is an olefin polymer, it may preferably be an alpha-olefin polymer; preferably, it may be a polymer of ethylene or a copolymer thereof with one of the compounds listed in Table I:

TABLE 1 propene butent-l pentene-l 3-methyl butene-l hexene-l 3-methyl pentene-l 4-methyl pentene-l heptene-l 3-methyl hexene-l 4-methyl hexene-l S-methyl hexene-l 3-ethyl pentene-l octene-l 3-methyl heptene-l 4-methyl heptene-l S-methyl heptene-l 6-methyl heptene-l 3-ethyl hexene-l 4-ethyl hexene-l 3-propyl hexene-l decene-l Preferred olefin polymer is polyethylene having a molecular weight T4,, of 50010,000, typically 8002,500, say 1,500.

When the first component is a hydrogenated olefin polymer, it may be one obtained by hydrogenation of the olefin polymer. Typically the hydrogenated polymer may include hydrogenated polybutadiene and hydrogenated copolymers of ethylene-butadiene, butadiene-styrene, butadiene-isoprene, ethylene-styrene, butadiene-butene-l, etc. Typically the molecular weight 1T1 may be 50050,000. A preferred illustrative composition may be polybutadiene having a molecular weight of 3,000 which has been hydrogenated.

When the first component is a halogenated olefin polymer, eg a halogenated alpha olefin polymer, it may be one obtained by halogenation (e.g., chlorinating or brominating) the olefin polymer. Typically the so-prepared halogenated alpha olefin polymer may contain 2-30 percent, preferably 5-15 percent, say 10 percent by weight of halogen. A preferred halogenated olefin polymer may be chlorinated polyethylene, typically containing 10-30 percent, say 20 percent by weight of chlorine and characterized by a molecular weight M, of 500-50,000, more specifically 1,500-l5,000, say 5,000.

In the preferred embodiment, the polymer may be a copolymer of an olefin, more preferably ethylene, with a second copolymerizable monomer. Preferably the copolymer may contain 3-40 moles of olefin, say ethylene, and one mole of copolymerizable comonomer and optionally one or more moles of other copolymerizable monomer. The comonomer may, in one embodiment,

be a vinyl ester of a monocarboxylic acid. Typical of such comonomers may be those listed in the following table.

TABLE 11 Vinyl acetate Vinyl propionate Vinyl butyrate Vinyl caproate Vinyl caprylate Vinyl caprate wherein X is H, halogen, alkyl, or aryl, and Y is halogen or --CO0R wherein R is alkyl, preferably C,-C,,, alkyl, morepreferably C -C alkyl or aryl.

When X is H, hydrogen, and Y is -COOR, the comonomer may be an alkyl acrylate, typically as set forth in the following table:

TABLE III Methyl acrylate Isobutyl acrylate Lauryl acrylate C Oxo-alkyl acrylate When X is halogen, e.g. chlorine, and Y is -COOR,

set forth in the following table:

TABLE IV Methyl chloroacrylate Methyl bromoacrylate Ethyl chloroacrylate Isobutyl chloroacrylate When X is alkyl, typically lower alkyl having 1-8 car- 0 bon atoms, e.g., methyl, and Y is COOR, the comonomer may be a methacrylate, typically as set forth in the following table:

TABLE V Methyl methacrylate Ethyl methacrylate Methyl ethacrylate isobutyl methacrylate Lauryl methacrylate is H or alkyl preferably having one to 16 carbon atoms.

Illustrative of these, may be those set forth in the following table:

TABLE VI Fumaric acid Maleic acid! Monomethyl fumarate Monobutyl fumarate Monohexyl maleate di-isopropyl maleate di-C Oxo fumarate di-lauryl fumar'ate di-ethyl methylfumarate When the comonomer polymerized with ethylene is an olefin hydrocarbon having more than two carbon atoms, it may be selected from the compounds of Table .1 supra. The preferred of such comonomers may be propylene. The preferred copolymers may be copolymers of ethylene-propylene containing 3-40 moles of ethylene and one mole of propylene, e.g. 5 moles of ethylene and one mole of propylene, having a molecu lar weight M,, of 500-50,000, preferably 1,500-15,000, say 5,000.

the comonomer may be a chloroacrylate, typically as 30 The preferred oil-soluble, first component, pourpoint depressant may be typically selected from the following table:

TABLE VII poly(ethylene/propylene) halogenated poly(ethylene/propylene) poly(ethylene/vinyl acetate) poly(ethylene/vinyl chloride) poly(ethylene/vinylidene chloride) poly(ethylene/isobutyl acrylate) poly(ethylene/methyl methacrylate) poly(ethylene/chloroacrylate) poly(ethylene/dimethyl fumarate) Most preferred is the copolymer of about 5 moles of ethylene with one mole of vinyl acetate having a molecular weight of about M of 2,000.

This oil-soluble pour-point depressant first component may be present in amount of 0001-05 parts, preferably 0.005-0.30 parts, say 0.02 parts per parts of oil.

The second component of the composition added to the middle distillate fuel oil may be a non-nitrogencontaining oil-soluble auxiliary flow-improving compound containing at least one straight chain (CH :polymethylene segment, wherein n is 10-30, and a bulky substituent on said polymethylene segment selected from the group consisting of (l) non-polar hydrocarbon moieties substantially free of saturated cyclic hydrocarbons and (ii) polar moieties containing or including halogen, oxygen, sulfur, or phosphorous.

The second component of the composition may be a hydrocarbon, halohydrocarbon, ester, acid (including anhydride), ether, ketone, etc.

It is a feature of the novel technique of this invention that many of the first components the oil-soluble pour point depressants may frequently contribute only little or marginal improvement in flow properties when used alone in difficult or unresponsive fuels such as some of the commonly available European fuels, e.g., a distillate fuel characterized by a 10 percent boliing point of 384F., a 90 percent boiling point of 643F., an aniline point of 163.5F., a pour point of +F., and a cloud point of 26F. (Fuel C).

Since the second component may normally be one which generally yields little or no flow-improving properties, it is unexpected that it should be able to enhance the flow-improving ability of the first component.

The ability of the combination of this invention to achieve outstanding results in practice of this invention may vary depending upon the particular fuel and the particular combination. The most desirable results may normally be achieved when the fuel is one generally acknowledged to be difficult, i.e., non-responsive to the impact of prior art flow improvers and/or when the flow improver (which may be satisfactory for normal fuels) fails, for some unexplained reason to provide the desired effect in the particular fuel oil.

The second component may be a non-nitrogencontaining, oil-soluble auxiliary flow-improving compound containing at least one (Cl-l polymethylene segment wherein n is -30 and a bulky substituent on said polymethylene segment selected from the group consisting of i non-polar hydrocarbon moieties free of saturated cyclic hydrocarbons, and

ii. polar moieties containing halogen, oxygen, sulfur, or phosphorous.

The second component may contain at least one (CH polymethylene segment wherein n is 10-30, preferably 14-24. Commonly such segments may include those derived from groups such as hexadecyl, octadecyl, pentacosyl, etc.

The molecule may include a bulky substituent, i.e., one which terminates or interrupts the chain (e.g., is positioned between two adjoining chains or is a side chain on a chain). The bulky substituent may be one which has a discontinuity or steric configuration to provide a non-continuous envelope along the molecule. Typically such bulky substituents may include aromatic rings such as phenyl, the double bond, halogen including chloro, bromo, etc., oxygen as in an acid, anhydride, alcphol or ester residue, ethers as in polyoxyethylene moieties, etc.

When the second component is a hydrocarbon, it may typically be one of those in the following table:

TABLE Vlll Phenyl pentadecane 2 l -Dotetracontene Dodecyl toluene Tetradecyl toluene Hexadecyl toluene Octadecyl toluene 2l-Dotetracontyl toluene Chlorowzx toluene condensate C -C internal olefin 19-Octatriacontene When the second component is a halohydrocarbon, it may typically be one of the following:

TABLE IX 21-Bromodotetracontane 2 l -C hlorodotetracontane Chlorowax C alkyl bromide C -56 alkyl chloride 19-chloroctatriacontane When the second component is an ester, it may typically be one of the following:

TABLE X Cholesteryl laurate Cholesteryl myristate Cholesteryl palmitate Cholesteryl erucate Trilaurin Phenyl stearate Sorbitan monopalmitate Sorbitan monostearate Sorbitan tristearate Sorbitol myristate Sorbitol laurate Sorbitol stearate Pentaerythrityl tetrastearate Pentaerythrityl tetralaurate Sorbitan monooleate Sucrose myristate Sucrose laurate Sucrose stearate Sorbitol oleate Benzoate of sorbitan monostearate Tristearin Dibehenyl adipate A particularly preferred class of esters is the sorbitan esters particularly those containing the following structures:

0 T CHOXCBZQA Y 0 oz CHzOA (CH,CH O),,. Typical available compositions may include those having the following designations: sorbitan monostearate; sorbitan tristearate; polyoxyethylene (20) sorbitan tristearate.

When the second component is an acid (including anhydrides), it may typically include the following:

TABLE XI Erucic acid Behenic acid Octadecylsuccinic anhydride (I -C Alkenylsuccinic anhydride l9-octatricontene/maleic anhydride condensate C -C internal olefin*/maleic anhydride condensate Mixtures of C thru C5, internal olefins When the second component is an ether, it may typically be the following:

TABLE XIII Polyoxyethylene (8) stearate Polyoxyethylene (8) laurate Polyoxyethylene (20) stearyl ether Polyoxyethylene (l) stearyl ether Polyoxyethylene (2) stearyl ether Polyoxyethylene (4) lauryl ether Polyoxyethylene (2) oleyl ether Polyoxyethylene (20) sorbitan tristearate Polyoxyethylene (20) sorbitan trioleate Tetrahydrofurfuryl palmitate Polyoxyethylene (20) oleylphenol Polyoxyethylene (6) dodecylphenol Polyethyleneglycol stearate Polyethyleneglycol stearate methyl ether The numbers in parentheses indicate the average number of oxyethylene groups per molecule.

A preferred polyether may have the formula R- (OCH,CH,) ,OH wherein R is stearyl.

When the second component is a ketone, it may commonly be prepared by acylation.

A particularly useful group of products may be those prepared by the Friedel-Craft-type acylation (preferably in the presence of aluminum chloride) of longchain (e.g., containing more than 30 carbon atoms) symmetrical internal olefins with an acyl halide typically Typical of the ketones may be those listed in the following table:

TABLE X111 21 -Dotetracontene/benzoyl chloride 2 1 -Dotetracontene/sebacoyl chloride 2 lDotetracontene/phthaloyl chloride C -C internal olefin/benzoyl chloride l9-Octatriacontene/benzoyl chloride! C -C olefin/benzoyl chloride C C olefin/sebacoyl chloride C olefin/benzoyl chloride C olefin/sebacoyl chloride 1 l Docosene/benzoyl chloride Myristophenon e The specific first and second components and relaw.

tive proportions thereof may vary dependingupon the. properties of the fuel oil. Commonly-the formulation may contain l-99 percent, preferably 4-97 percent, of the first component, the remainder being. the second component.

Thusthe novel fuel oil compositions which may be prepared by the process of this invention may contain the following proportions of ingredients (per 100 parts of oil):

Component Broad Range Preferred First Component 0.00l0.5 0.005-0t3 Second Component 0.00l0.5 0005-03 In the preferred embodiment the first component and the second component may be employed in the form of a concentrate in a diluent-solvent which is soluble in the oil to which the concentrate is to be added. Typically, such concentrates may contain 5 to parts,

preferably 10 to 50 parts, say40 parts of first and see ond components in 0-100 parts of dilient-solvent. This diluent-solvent may be an inert liquid in: which the first and the second components are soluble or dispersible.

Although each of the first and second componentsof the composition may be separately formulated in diluent-solvent, it is preferred that they be formulated as a concentrate in a single diluent-solvent; and in the preferred embodiment, the diluent-solvent may be theoil to which the composition is to be added. Typically, this solvent may be a material such as Solvent 325 Neutral, a light lubricating oil base stock, a vacuum gas oil, a heavy aromatic naphtha, Varsol, kerosene, ora distillate heating oil. Other appropriate solvents will be obvi ous to those skilled in the art.

In the practice of this invention, both the first and the second components may be added to a fuel oil in amount (as a mixture in one diluent-solvent or each in a separate diluent solvent) sufficient to improve the flow properties of the oil. Preferably this amount is about 0.002 to 1.0 parts by weight, typically 0.04 parts by weight per parts of oil.

Practice of the process of this invention in accordance with certain of its aspects, may be effected by adding the first and second components (either sequens tially or simultaneously) to the oil, and mixing, thereby forming a petroleum oil composition. Mixing may be done continuously or batchwise. Typically, such formulations may be prepared by adding the flowimproving:

amount of said flow improvers to a body of the oil at a temperature up to 300F., preferably greater than 100F. When the first and second components are added as a concentrate in diluent-solvent, the preferrd temperature may be 60200F., say F. When :the first and second components are added, without diluent-solvent, the preferred temperature may be -300F., say 200F.

Practice of this invention will be apparent to those skilled in the art from the following examples wherein, as elsewhere in this specification, all parts are parts by weight.

DESCRIPTION OF PREFERRED EMBODIMENT In the examples which follow, the following middle distillate oils (which are either non-responsive or difficultly responsive to prior art flow improvers) were tested:

Fuel A Number 2 Heating Oil. A middle distillate oil having an IBP of 374F., a 10 percent boiling point of 42IF., a 90 percent boiling point of 569F., a final boiling point of 614F., a cloud point of 2F., a pour point of F., an aniline point of l36F., and containing 3.1 percent wax.

Fuel B A middle distillate fuel oil having a -6F. cloud point, a pour point of F., an aniline point of 137F., a 10 percent boiling point of 474F., and a 90 percent boiling point of 556F.

Fuel C A European middle distillate fuel oil having a 10 percent point of 384F., a 90 percent boiling point of 643F., an aniline point of 163.5F., a pour point of +5F., and a cloud point of 26F.

Fuel D A middle distillate fuel oil from a European source having a 10 percent boiling point of 384F., a 90 percent boiling point of 610F., an aniline point of 157F., a pour point of 0F., and a cloud point of 16F.

Fuel E A middle distillate fuel oil from a European source having a 10 percent boiling point of 372F., a 90 percent boiling point of 594F., an aniline point of 150.5F., a pour point of 10F., and a cloud point of +6F.

In each Example of the first series which follows, the middle distillate fuel oil was tested in a control example to determine its flow characteristics by the Enjay Programmed Fluidity Test supra. Typical compositions of this invention containing equal parts by weight of active ingredient of the first and second components were added, in all cases, in the Experimental runs. In further control examples, there was added to the fuel the same total amount of either the first of the second component.

In these Examples, the following middle distillate pour-depressing materials were oil concentrates employed as the first component of the compositions, which concentrates contained the following active ingredients:

I A copolymer of ethylene-vinyl acetate of M,. of about 2,000, containing about 38 percent by weight of vinyl acetate, and containing about 5 moles of ethylene to 1 mole of vinyl acetate.

II- A chlorinated ethylene polymer having a molecular weight M, of about 3500 and a chlorine content of about percent.

III- A polymer consisting essentially of ethylen e and isobutyl acrylate having a molecular weight M of about 3,000 and an isobutyl acrylate content of about 4 percent.

In these Examples, the following were employed as the second component of the compositions:

. Polyoxyethylene (20) sorbitan tristearate. .'Polyoxyethylene (2) stearyl ether.

. Polyoxyethylene (l0) stearyl ether.

. Polyoxyethylene (20) stearyl ether.

. Sorbitan monopalmitate.

. Sorbitan tristearate.

TABLE XIV First Second Total Example Compo- Compo- Cone. Rating nent nent I I 0.10 74 2 l l 0.04 100 3 l 2 0.04 100 4 l 3 0.04 5* Il 0.10 44 6 ll 1 0.10 7 ll 2 0.10 100 8 II 3 0.10 92 9 ll 4 0.10 92 10* Ill 0.10 45 11 000 2 0.10- 78 12 III 3 0.10 100 13 III 4 0.10 93 Control In the above Table the fuel oil was Fuel B.

For example, in Example 1, presence in the base oil (Fuel B used as base oil in Examples l-l3) of 0.10 parts, per 100 parts of base oil, of first component I gives a rating of 74 when measured by the Enjay Programmed Fluidity Test supra, i.e., in the test time, 74 percent of the fuel passed through the orifice. The original fuel oil is rated at 0-20.

Unexpectedly it is found that use of 0.04 parts total of first component I and second component 1 gives a rating of 100 i.e., although the total amount of additive employed is only 40 percent of that employed in Example I, the amount of oil passing through the orifice in test time is 100 percent in contrast to 74 percent of Example 1.

Although not set forth in the Table, it may be noted that use of 0.04 parts of second component 1 (and 0 parts of first component I) will yield an unsatisfactory rating.

Similarly, comparison of Control Example 5 with experimental Examples 6-9 reveals that the flow properties may be more than doubled by practice of the instant invention. A comparison of control Example 10 with experimental Examples 1 l-l3 reveals similar outstanding improvements.

. In the following series of Examples, the flow properties of Fuels C, D, and E were tested by the CFPP Test noted supra. In each example, the toal amount of added first and second component was 0.015 parts per 100 parts of Fuel. The test rating was determined as the temperature (F.) at which the oil no longer flows.

TABLE XV First Second Example Compo- Compo- Fuel Rating F.

nent nent 14 I C 20 15 l S C 6 16 I 6 C l2 17 I l C 14 18 I 3 C 10 19 l 4 C 16 20 l D 10 21 I 5 D 2 22 I 6 D 4 23 I l D 2 24 I 2 D 4 25 I 3 D 0 26 I 4 D 6 27 I E 2 28 l 5 E 8 29 I 6 E 4 30 I l E 4 31 1 2 E 6 32 l 3 E 12 33 l 4 E 8 34 Ill D 2 35 Ill 4 D 2 36 III E 4 37 Ill 5 E 8 38 Ill 6 E 8 39' Ill 1 E -l 40 ll] 2 E -8 41 Ill 3 E 8 42 Ill 4 E 8 Rating of Oils with No Additive Oil Rating C 26 D 12 E 6 *Control From the above table it may be apparent that the novel technique of this invention permits attainment of unexpected results. Base Oil C has a rating (with neither first nor second component being present) of 26F. In Example 14, presence in the base oil (Oil C) of 0.015 parts of first component per 100 parts of base oil yielded a rating of 20. Addition of the same total amount (of a 50-50 mixture by weight) of First Component l and Second Component (q.v. Example 15) desirably decreased the rating to 6F.

Comparable improvement may be observed by comparing, e.g., control Examples and 27 with the experimental Examples immediately following each.

It will be apparent to those skilled in the art that varying results may be achieved with respect to different of the difficult" fuels by use of selected combinations of additives. Because of the peculiar, widely-varying, and totally unexpected nature of the difficult fuels, it is not always possible to predict few degree of improvement attained; and in some instances the improvement attained with certain combination may be greater. For

instance, where it is less it may be found that other combinations may yield improvement with the fuel; and the combination may be effective in improving another fuel. For example, combination [-4 appears to yield little improvement with Fuels C and D (Examples 19 and 26); but yield significant improvement with Fuel E (Example 33). Those skilled in the art will appreciate this factor and will readily be able to determine from a fee simple observations which combinations will be most effective for particular fuels. Thus it is unexpected that the novel invention permits attainment of markedly improved ratings in oils which are non-responsive to a given first component additive alone. It will also be apparent that some of these combinations may be more effective than certain other combinations.

In each of the second series of Examples which follows, the middle distillate fuel oil was tested in a control example to determine its flow characteristics by the Enjay Programmed Fluidity Test supra. Typical compositions of this invention containing equal parts by weight of active ingredient of the first and second components were added in the Experimental runs. In a first control example (Example 43), there was added to the fuel the same total amount of only the first component.

In these examples, the following pour point depressant concentrate material containing the following active ingredient was employed as the first component of the compositions:

I A copolyrner of ethylene-vinyl acetate of M, of about 2,000, containing about 38 percent by weight of vinyl acetate, and pontaining about 5 moles of ethylene to one mole of vinyl acetate.

In the following Table there are tabulated for each Example, the second component (employed in a 5050 percent mixture by weight of a total weight of additive per 100 parts of oil with the noted first compo nent), and the rating. The rating :is given, based upon the results of the Enjay Programmed Fluidity Test supra. For the tests which are passes, the rating is given in terms of percent.

TABLE XVI Total Weight of Ex. Second Component First and Second Component 0.04 0.02 43 None 100 50 44 21-Dotetracontene 98 45 Dotetracontance 40 40 46 2l-Dotetracontyl toluene 9.0 47 C internal olefin 98 48 l9-octatriacontene 100 49 ZLbromodotetracontance 100 100 50 21-chlorodotetracontance -tm 100 51 C secondary alkyl chloride t n 98 52 tristearin tn I00 53 sorbitan monopalmitate 98 98 54 sorbitan monostearate 92 98 55 sorbitan tristearate 100 98 56 sorbitol stearate 100 100 57 sorbitan monostearate benzoate 98 73 58 octadecyl succinic anhydride 84 59 polyoxyethylene(20) stearyl ether 77 60 polyoxyethylene( l0) stearyl ether 98 61 polyoxyethylene(20) sorbitan tristearate 98 98 62 polyethylene glycol stearate 80 63 polyethylene gylcol stearate methyl ether tn 64 2l-dotetracontene/benzoyl chloride 100 85 65 2ldotetracontenelsebacoyl chloride l00 C internal olefin/benzoyl chloride tn 92 Control From the above table it may be apparent that the novel technique of this invention permits attainment of unexpected results.

For example, in Example 43, presence in the base oil Fuel A of 0.04 parts per 100 parts of base oil, of first component I alone gives a rating of 100 when measured by The Enjay Programmed Fluidity Test supra, i.e., in the test time, 100 percent of the fuel passed through the orifice. (The original fuel oil would be rated at 0-20.). When the concentration of component I was 0.02 parts, the base oil failed the test, i.e., less than about 75 percent passed through the orifice. Testing of Fuel A with second component (B) alone at high con centrations (even up to 0.1 percent) does not give a pass rating. For example, the component of Example 64 gives an 0 rating in the test at 0.1 concentration when used alone.

Unexpectedly it'is found (e.g., Example 47) that use of 0.04 parts total of first component I and second component gives a ratng of 98 i.e. although the total amount of active first component employed is the same as the concentration at which it failed in Example 43. The amount of oil pssing through the orifice in test time is 98 percent in contrast to less than 50 percent of Example 43. Therefore, although the second component is inactive alone, it does unexpectedly yield improved results.

Similarly, comparison of Control Example 43 with e.g., experimental Examples 49,50, 56 61, 63, etc. reveals that the flow properties may be substantially increased by practice of the instant invention. It has also been found, for example that use of lesser amounts (e.g., 0.01 parts total of first component and the second component of Example 50) yields a rating of 100 in The Enjay Programmed Fluidity Test. This indicates that improvement of at least fourfold is achieved.

It will be apparent that the specific nature of the various distillate fuels may vary widely in terms of wax content, etc. and therefore in response to flow inprovers. It will be found that certain combinations of additives may be more effective in certain oils than other oils.

For example, the combination of first component (I) with second component (2) may be found, as noted in Table XIV to permit attainment of outstanding results in Fuel B (which is generally considered a difficultly responsive fuel) whereas the same combination in the same concentration may be found to give a lesser result when used in Fuel A (which is considered to be more responsive to flow improvers than is Fuel B).

In this instance, the novel invention permits attainment of improvement, the amount of improvement depending for example upon whether the oil is, e.g., a heating oil or a diesel 'oil. In the case of a heating oil, it may be found that the Fludiity Test is significant, whereas as with a diesel fuel, it may be found that a CFPP test is significant i.e., the determinative test for a given oil may depend upon whether the problems most frequently associated with the oil arise because the oil is to be passed through a small tube (as in the case of a heating oil) or through a screen (as in the case of a diesel oil).

It will be apparent that practice of this novel invention permits fullest realization of the flow improving properties of the first component pour depressant compositions. These compositions may be readily available or they may be prepared by desired techniques, which are known in the art.

While as previously indicated, it is only necessary that the oil-soluble flow-improving compound have a C to C straight-chain group and a bulky substituent as previously specified, particularly preferred are those compounds having a total of 12 to 200 carbon atoms, preferably 30-l25 carbon atoms, which contains at least one of said C to C straight-chain groups and which include:

1. Alkyl aromatics including those having 1 to 4 alkyl groups each of which is a C,-C alkyl and one of which is a C -C: alkyl, per aromatic nucleus which can have 1 to 3 rings such as benzene, naphthalene, anthracene, etc.

2. Halohydrocarbons with l to 4 halogens per molecule, which hydrocarbons can be straightor branchedchain, aliphatic, alkaryl, etc., including the alkyl aromatics of (1) supra and the acids of (3) infra.

3. Acids and their anhydrides, having 1 to 3 carboxylic groups, which may be aliphatic, aryl, alkaryl, cycloaliphatic groups, etc.

4. Esters such as those of acids such as (3) above and preferably of C to C fatty acids, preferably straightchain and saturated, with alcohols having 1 to 6 hydroxy groups of which at least one hydroxy group has been esterified, and which alcohol contains one to 30 carbon atoms which may be straightor branchedchain aliphatic, aryl, alkaryl, etc. Particularly, useful alcohols include the sorbitols, mannitols, etc., including their mono-dehydrated forms such as sorbitan, etc.

5. Polyethers or alkoxylated materials wherein l to 30 alkoxy groups of two to 26 carbon atoms such as ethylene oxide, propylene oxide, docosanyl alpha olefin oxide, are attached to another moiety, e.g. the acids of (3) above or the alcohols of (4), i.e., C alcohols with 1-6 hydrogen groups.

6. Unsaturated aliphatic hydrocarbons containing 1 to 4 ethylenically unsaturated bonds.

7. Derivatized compounds of (6) above wherein a further reaction is carried out at l or more of said un- 5 saturated bonds including:

a. Acylation with acyl halides wherein the unsaturated aliphatic hydrocarbon of (6) is reached with l to 4 moles of an acyl halide ll R-C-Cl wherein R is a C, to C hydrocarbon group, including straightor branched-chain aliphatics, aromatics, 15 alkyl aromatics, etc.

b. Halogenation or hydrohalogenation particularly chlorination and bromination, to yield derivatives of the above wherein the halogen or hydrogen halide, e.g., HCl, is added to at least one of the ethylenically unsaturated double bonds. (8) A saturated C alkanol derivative, e.g. esters of acids of (3); and polyethers of the alkoxy materials of (5).

Generally speaking, the polymeric pour depressant,

i.e., the first component, is relatively expensive while the second component may be less expensive. As previously shown, the combination of the first and second component frequently gives a performance advantage, particularly in fuel oils which normally give a poor response to the polymeric pour depressant per se. in ad- 30 dition, the combination also frequently will give an economic advantage, even in oils which are very responsive to the polymeric flow improver, by simply permitting the substitution of a part of the expensive polymeric first component with less expensive second component while still obtaining the desired performance. In addition, yet another advantage is obtained by simply placing another tool in the hands of the additive formulator for tailoring the additive composition to obtain the optimum, economic performance for a particular fuel oil, or class of fuel oils.

' Although this invention has been illustrated by reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made which clearly fall within the scope of this invention.

What is claimed is:

1. A fuel oil composition comprising a. a major portion of a middle distillate fuel boiling in the range 250750F. and a flow improving amount of a flow-improving system containing:

b. as a first component, in the range of about 0.005 to 0.3 parts, per 100 parts of oil, of an oil-soluble, pour p021} depressant polymer having a molecular weight M,, in the range of about 500-50,000 selected from the group consisting of:

1. chlorinated ethylene polymer,

2. copolymer comprising 3-40 molar proportions of ethylene and a molar proportion of a copolymerizable comonomer selected from the group consisting of:

i. a vinyl ester of a C monocarboxylic acid,

and ii. an ethylenically unsaturated ester wherein X is H, or C, to C alkyl and Y is -COOR wherein R is a C alkyl group, and

c. as a secondcomponent, in the range .of about 0.005 to 0.3 parts, per 100 parts of oil, of a non-nitrogen-containing oil-soluble auxiliary flowimproving compound having a total of 12 to 200 carbon atoms, containing at least one straight chain (CH polymethylene segment wherein n is 10-30 and a bulky substituent on said polymethylcne segment, said compound being selected from the group consisting of:

1. alkyl aromatics having 1 to 4 alkyl groups, each in the C, to C range, per aromatic nucleus,

2. halogenated hydrocarbons having 1 to 4 halogens per molecule,

3. acids and their anhydrides having 1 to 3 carboxylic groups,

4. esters of C to C fatty acids with C, to C alcohols having 1 to 6 hydroxy groups wherein at least one hydroxy group has been esterified,

5. polyethers containing 1 to 30 alkoxy groups of two to 26 carbon atoms attached to said acids of (3) above or to said C, to C alcohol of (4) above,

6. unsaturated aliphatic hydrocarbons containing 1 to 4 ethylenically unsaturated bonds,

7. derivatized compounds of (6) above wherein a further reaction at one or more of said unsaturated bonds is carried out by:

a. acylation with 1 .to 4 moles of acyl halide of the formula:

where R is a C, to C hydrocarbon group, and

b. halogenation and hydrodehalogenation, 8. saturated C to C alkanol esters of said acids of (3), and 9. polyethers of the alkoxy materials of 2. A fuel oil composition according to claim 1, wherein said first component is chlorinated polyethylene containing about 10 to 30 percent chlorine and having a ill in the range of about 1500 to 15,000.

3. A fuel oil composition according to claim 1, wherein said first component is said copolymer comprising ethylene and vinyl ester of said monocarboxylic acid.

4. A fuel oil composition according to claim 3, wherein said vinyl ester is a vinyl ester of a C, to C monocarboxylic acid.

5. A fuel oil composition according to claim 4, wherein said ester is vinyl acetate.

6. A fuel oil composition according to claim 1, wherein said first component is said copolymer of ethylene and said ethylenically unsaturated ester.

7. A fuel oil composition according to claim 6, wherein said first component is said copolymer comprising ethylene and alkyl acrylate wherein said alkyl group contains two to eight carbon atoms.

8. A fuel oil composition according to claim 7,

9. A fuel oil composition according to claim 1, wherein said second component is an alkyl aromatic having from 1 to 4 alkyl groups, each in the C, to C range, per aromatic nucleus.

10. A fuel oil composition according to claim 1, wherein said second component is a halogenated hydrocarbon having l to 4 halogens per molecule.

11. A fuel oil composition according, to claim 1, wherein said second component is an acid or anhydride having 1 to 3 carboxylic groups.

12. A fuel oil composition according to claim 1, wherein said second component is an ester of C to C fatty acid with C, to C alcohol having 1 to 6 hydroxy groups wherein at least one hydroxy group has been esterified.

13. A fuel oil composition according to claim 1, wherein said second component is polyether.

14. A fuel oil composition according to claim 1, wherein said second component is an unsaturated aliphatic hydrocarbon containing 1 to 4 ethylenically unsaturated bonds.

15. A fuel oil composition according to claim 1, wherein said second component is one of said derivatized compounds.

16. A fuel oil composition according to claim 1, wherein said second component is a C, to C alkanol ester of an acid or anhydride having 1 to 3 carboxylic groups.

17. A fuel oil according to claim 1, wherein said first component is said polymer of 3 to 40 moles of ethylene and said copolymerizable monomer and said second component is an ester of C, to C fatty acid with C, to C alcohol having 1 to 6 hydroxy groups wherein at least one hydroxy group has been esterified.

18. A fuel oil according to claim 17, wherein said copolymerizable monomer is either vinyl acetate or isobutyl acrylate, and said second component is alkoxylated with 1 to 30 alkoxy groups selected from the group consisting of ethylene oxide and propylene oxide.

19. A fuel oil according to claim 18, wherein said second component is a sorbitan ester of stearic or .palmitic acid ethoxylated with ethylene oxide.

20. A composition adapted to be used as a flow improver comprising 0-100 parts of inert diluent-solvent and 10-70 parts of a mixture of:

a. as a first component, an oil-solible, pour point depressant polymer having a molecular weight if; in the range of about 500-50,000 selected from the group consisting of:

1. chlorinated ethylene polymer,

i. a vinyl ester of a C monocarboxylic acid,

and ii. an ethylenically unsaturated ester wherein X is H, or C, to C alkyl and Y is COOR wherein R is a C,.,,, alkyl group, and

b. as a second component, a non-nitrogen-containing oil-soluble auxiliary flow-improving compound having a total of 12 to 200 carbonatoms, containing at least one striaght chain (CH polymethylene segment wherein n is 10-30 and a bulky substituent on said polymethylene segment, said compound being selected from the group consisting of:

1. alkyl aromatics having 1 to 4 alkyl groups, each in the C to C range, per aromatic nucleus,

2. halogenated hydrocarbons having I to 4 halogens per molecule,

3. acids and their anhydrides having 1 to 3 carboxylic groups,

4. esters of C to C fatty acids with C to C alcohols having 1 to 6 hydroxy groups wherein at least one hydroxy group has been esterified,

5. polyethers containing 1 to 30 alkoxy groups of two. to 26 carbon atoms attached to said acids of (3) above or to said C to C alcohol of (4) above,

a. acylation with l to 4 moles of acyl halide of the formula:

W Et yl-Cl 21. A composition according to claim 20, wherein said first component is said polymer of 3 to 40 moles of ethylene and said copolymerizable monomer and said second component is an ester of C to C fatty acid with C to C alcohol having 1 to 6 hydroxy groups wherein at least one hydroxy group has been esterified.

22. A composition according to claim 21, wherein said copolymerizable monomer is either vinyl acetate or isobutyl acrylate, and said second component is alkoxylated with 1 to 30 alkoxy groups selected from the group consisting of ethylene oxide and propylene oxide.

23. A composition according to claim 22, wherein said second component is a sorbitan ester of stearic or palmitic acid ethoxylated with ethylene oxide.

UNITED STATES PATENT OFFICE QERTIFICATE OF CORRECTION Q PATENT NO. 3,762,888

DATED October 2, 1973 INVENTOMS) Alfred E. Kober and Albert Rossi H is certified that error appears in the ab0veidentified patent and that said Letters Patent a are hereby corrected as shown below:

Column 14, Table XVI, line 10, transfer heading "First and Second Component" from left side of table to right side below "Total Weight of"; in same Table XVI in Ex. 45, 49 and 50 "contance" should read contane-; in Ex. 50 delete "-tm" and transfer the numeral "100" to extreme right column; in Ex. 51 delete "t n" and transfer "98" under column heading "0.04"; in Ex. 52 delete "tn" and transfer "100" under column heading "0.04"; in Ex. 63, second line, indent "methyl ether", delete "tn" and transfer "100" to the column headed "0.04"; in Ex. 66, delete "tn" and transfer "92" to the column headed "0.04".

Signed and Sealed this eleventh a O [SEAL] I) y F May 1976 Q Arrest.

IjUlH C. Mrs-SON C. MARSHALL DANN Hrs/mg ()jflttf ('ummissr'mu'r oj'lau'nrs and Trademarks O

Claims

2. copolymer comprising 3-40 molar proportions of ethylene and a molar proportion of a copolymerizable comonomer selected from the group consisting of: i. a vinyl ester of a C1-17 monocarboxylic acid, and ii. an ethylenically unsaturated ester
2. halogenated hydrocarbons having 1 to 4 halogens per molecule,
2. A fuel oil composition according to claim 1, wherein said first component is chlorinated polyethylene containing about 10 to 30 percent chlorine and having a Mn in the range of about 1500 to 15,000.
2. copolymer comprising 3-40 molar proportions of ethylene and a molar proportion of a copolymerizable comonomer selected from the group consisting of: i. a vinyl ester of a C1-17 monocarboxylic acid, and ii. an ethylenically unsaturated ester
2. halogenated hydrocarbons having 1 to 4 halogens per molecule,
3. acids and their anhydrides having 1 to 3 carboxylIc groups,
3. A fuel oil composition according to claim 1, wherein said first component is said copolymer comprising ethylene and vinyl ester of said monocarboxylic acid.
3. acids and their anhydrides having 1 to 3 carboxylic groups,
4. esters of C2 to C26 fatty acids with C1 to C30 alcohols having 1 to 6 hydroxy groups wherein at least one hydroxy group has been esterified,
4. A fuel oil composition according to claim 3, wherein said vinyl ester is a vinyl ester of a C2 to C9 monocarboxylic acid.
4. esters of C2 to C26 fatty acids with C1 to C30 alcohols having 1 to 6 hydroxy groups wherein at least one hydroxy group has been esterified,
5. polyethers containing 1 to 30 alkoxy groups of two to 26 carbon atoms attached to said acids of (3) above or to said C1 to C30 alcohol of (4) above,
5. A fuel oil composition according to claim 4, wherein said ester is vinyl acetate.
5. polyethers containing 1 to 30 alkoxy groups of two to 26 carbon atoms attached to said acids of (3) above or to said C1 to C30 alcohol of (4) above,
6. unsaturated aliphatic hydrocarbons containing 1 to 4 ethylenically unsaturated bonds,
6. A fuel oil composition according to claim 1, wherein said first component is said copolymer of ethylene and said ethylenically unsaturated ester.
6. unsaturated aliphatic hydrocarbons containing 1 to 4 ethylenically unsaturated bonds,
7. derivatized compounds of (6) above wherein a further reaction at one or more of said unsaturated bonds is carried out by: a. acylation with 1 to 4 moles of acyl halide of the formula:
7. A fuel oil composition according to claim 6, wherein said first coMponent is said copolymer comprising ethylene and alkyl acrylate wherein said alkyl group contains two to eight carbon atoms.
7. derivatized compounds of (6) above wherein a further reaction at one or more of said unsaturated bonds is carried out by: a. acylation with 1 to 4 moles of acyl halide of the formula:
8. A fuel oil composition according to claim 7, wherein said ester is a copolymer comprising ethylene and isobutyl acrylate having a molecular weight in the range of about 1,500 to 15,000.
8. saturated C10 to C26 alkanol esters of said acids of (3), and
8. saturated C10 to C26 alkanol esters of said acids of (3), and
9. polyethers of the alkoxy materials of (5).
9. polyethers of the alkoxy materials of (5), wherein said mixture contains about 4 to 97 percent of said first component with the remainder of said mixture being said second component.
9. A fuel oil composition according to claim 1, wherein said second component is an alkyl aromatic having from 1 to 4 alkyl groups, each in the C1 to C30 range, per aromatic nucleus.
10. A fuel oil composition according to claim 1, wherein said second component is a halogenated hydrocarbon having 1 to 4 halogens per molecule.
11. A fuel oil composition according to claim 1, wherein said second component is an acid or anhydride having 1 to 3 carboxylic groups.
12. A fuel oil composition according to claim 1, wherein said second component is an ester of C2 to C26 fatty acid with C1 to C30 alcohol having 1 to 6 hydroxy groups wherein at least one hydroxy group has been esterified.
13. A fuel oil composition according to claim 1, wherein said second component is polyether.
14. A fuel oil composition according to claim 1, wherein said second component is an unsaturated aliphatic hydrocarbon containing 1 to 4 ethylenically unsaturated bonds.
15. A fuel oil composition according to claim 1, wherein said second component is one of said derivatized compounds.
16. A fuel oil composition according to claim 1, wherein said second component is a C10 to C26 alkanol ester of an acid or anhydride having 1 to 3 carboxylic groups.
17. A fuel oil according to claim 1, wherein said first component is said polymer of 3 to 40 moles of ethylene and said copolymerizable monomer and said second component is an ester of C2 to C26 fatty acid with C1 to C30 alcohol having 1 to 6 hydroxy groups wherein at least one hydroxy group has been esterified.
18. A fuel oil according to claim 17, wherein said copolymerizable monomer is either vinyl acetate or isobutyl acrylate, and said second component is alkoxylated with 1 to 30 alkoxy groups selected from the group consisting of ethylene oxide and propylene oxide.
19. A fuel oil according to claim 18, wherein said second component is a sorbitan ester of stearic or palmitic acid ethoxylated with ethylene oxide.
20. A composition adapted to be used as a flow improver comprising 0-100 parts of inert diluent-solvent and 10-70 parts of a mixture of: a. as a first component, an oil-solible, pour point depressant polymer having a molecular weight Mn in the range of about 500-50,000 selected from the group consisting of:
21. A composition according to claim 20, wherein said first component is said polymer of 3 to 40 moles of ethylene and said copolymerizable monomer and said second component is an ester of C2 to C26 fatty acid with C1 to C30 alcohol having 1 to 6 hydroxy groups wherein at least one hydroxy group has been esterified.
22. A composition according to claim 21, wherein said copolymerizable monomer is either vinyl acetate or isobutyl acrylate, and said second component is alkoxylated with 1 to 30 alkoxy groups selected from the group consisting of ethylene oxide and propylene oxide.
23. A composition according to claim 22, wherein said second component is a sorbitan ester of stearic or palmitic acid ethoxylated with ethylene oxide.