Additive compositions and to fuel oils

Abstract

An additive composition containing a polymer (A) and an anti-static additive (B). The polymer (A) has the following monomer components: (i) one or more compounds of formula (I) ##STR00001##
wherein R.sub.1 is hydrogen or CH.sub.3; and R.sub.2 is a hydrocarbon group having 6 to 30 carbon atoms and is a straight-chain or branched-chain alkyl group, or an aliphatic or aromatic cyclic group;
(ii) one or more compounds of formula (II) ##STR00002##
wherein R.sub.1 has the meaning above and wherein R.sub.3 is hydrogen or C.sub.1-C.sub.22 alkyl; each R.sub.4 is independently hydrogen or C.sub.1-C.sub.22 alkyl; R.sub.5 is hydrogen, a substituted or unsubstituted aliphatic or aromatic cyclic group, or a substituted or unsubstituted straight-chain or branched-chain alkyl group having 1 to 22 carbon atoms; n=0 or an integer from 1 to 22; and m is an integer from 1 to 30; and
(iii) one or more compounds of formula (III) ##STR00003##
wherein R.sub.6, R.sub.7, R.sub.8, R.sub.9 and R.sub.10 are each independently hydrogen, a straight-chain or branched-chain alkyl group having 1 to 20 carbon atoms which may be substituted or unsubstituted, hydroxyl, NH.sub.2, or wherein two or more of R.sub.6, R.sub.7, R.sub.8, R.sub.9 and R.sub.10 may together form an aliphatic or aromatic ring system, which ring system may be substituted or unsubstituted. The anti-static additive (B) is (iv) an olefin polysulfone and (v) a polymeric polyamine reaction product of epichlorohydrin and an aliphatic primary monoamine or an N-aliphatic hydrocarbyl alkylene diamine, or the sulfonic acid salt of the polymeric polyamine reaction product. The weight:weight ratio of the polymer (A) to the anti-static additive (B) in the additive composition is from about 1:1 to about 500:1.

Claims

1. An additive composition comprising a polymer (A) and an anti-static additive (B) wherein polymer (A) comprises the following monomer components: (i) one or more compounds of formula (I); ##STR00007## wherein R.sub.1 is hydrogen or CH.sub.3; and R.sub.2 is a hydrocarbon group having 6 to 30 carbon atoms and is a straight-chain or branched-chain alkyl group, or an aliphatic or aromatic cyclic group; (ii) one or more compounds of formula (II); ##STR00008## wherein R.sub.1 has the meaning above and wherein R.sub.3 is hydrogen or C.sub.1-C.sub.22 alkyl; each R.sub.4 is independently hydrogen or C.sub.1-C.sub.22 alkyl; R.sub.5 is hydrogen, a substituted or unsubstituted aliphatic or aromatic cyclic group, or a substituted or unsubstituted straight-chain or branched-chain alkyl group having 1 to 22 carbon atoms; n=0 or an integer from 1 to 22; and m is an integer from 1 to 30; and (iii) one or more compounds of formula (III); ##STR00009## wherein R.sub.6, R.sub.7, R.sub.8, R.sub.9 and R.sub.10 are each independently hydrogen, a straight-chain or branched-chain alkyl group having 1 to 20 carbon atoms which may be substituted or unsubstituted, hydroxyl, NH.sub.2, or wherein two or more of R.sub.6, R.sub.7, R.sub.8, R.sub.9 and R.sub.10 may together form an aliphatic or aromatic ring system, which ring system may be substituted or unsubstituted; and wherein anti-static additive (B) comprises (iv) an olefin polysulfone and (v) a polymeric polyamine reaction product of epichlorohydrin and an aliphatic primary monoamine or an N-aliphatic hydrocarbyl alkylene diamine, or the sulfonic acid salt of the polymeric polyamine reaction product; and wherein the weight:weight ratio of the polymer (A) to the anti-static additive (B) in the additive composition is from about 1:1 to about 500:1.

2. An additive composition according to claim 1 wherein R.sub.3 and each R.sub.4 are hydrogen.

3. An additive composition according to claim 1 wherein n=1.

4. An additive composition according to claim 1 wherein R.sub.2 is a straight-chain alkyl group having 12 to 18 carbon atoms.

5. An additive composition according to claim 1 wherein R.sub.1 in formula (I) and in formula (II) is CH.sub.3.

6. An additive composition according to claim 1 wherein R.sub.6, R.sub.7, R.sub.8, R.sub.9 and R.sub.10 are each hydrogen.

7. An additive composition according to claim 1 additionally comprising an organic liquid.

8. A fuel oil composition comprising a major amount of a fuel oil and a minor amount of an additive composition according to claim 1.

9. A fuel oil composition according to claim 8 wherein the additive composition is present in the fuel oil in an amount of between 5 and 1000 parts per million by weight based on the weight of the fuel oil (wppm).

10. A fuel oil composition according to claim 9 wherein the additive composition is present in the fuel oil in an amount of between 5 and 500 wppm.

11. A fuel oil composition according to claim 10 wherein the additive composition is present in the fuel oil in an amount of between 5 and 200 wppm.

12. A method of increasing the electrical conductivity of a fuel oil, wherein the fuel oil contains an anti-static additive (B) as defined in claim 1, the method comprising the addition of a polymer (A) as defined in claim 1 to the fuel oil; wherein the weight:weight ratio of the polymer (A) to the anti-static additive (B) in the fuel oil is from about 1:1 to about 500:1.

Description

REPRESENTATIVE SYNTHESIS EXAMPLES

(1) To a clean, dry Schlenk tube equipped with a magnetic stirrer was added lauryl methacrylate (9.4 g), styrene (1.6 g) and a polyethylene glycol methacrylate (7.0 g) where the polyethylene glycol segment had a molecular weight of around 500 (PEGMA500) together with AIBN (0.1 g) and butanone (40 ml). The resulting mixture was freeze-thaw degassed three times and then the tube was filled with nitrogen. The tube was then placed in a preheated aluminium heating block atop a magnetic stirrer/hotplate and a catalyst complex, CoBF (1 ml of a 1.310.sup.3 mol dm.sup.3 solution) was added by syringe. The reaction mixture was left stirring at 80 C. for 4 hours under positive nitrogen pressure to obtain the polymer.

(2) For polymer A7 below, a polyethylene glycol methacrylate where the polyethylene glycol segment had a molecular weight of around 360 (PEGMA360) was used.

(3) The same procedure was used to produce HEMA-containing polymers by substituting the polyethylene glycol methacrylate with hydroxyethyl methacrylate.

(4) The following table details examples of polymers (A) which were synthesised as described above.

(5) TABLE-US-00001 Polymer Percentage composition (mole %) (A) formula (II) C12MA styrene Mn A1 46.sup.(PEGMA500) 48 6 24,500 3.6 A2 29.sup.(PEGMA500) 47 24 12,900 2.3 A3 26.sup.(PEGMA500) 52 22 10,700 1.9 A4 28.sup.(PEGMA500) 51 21 12,500 2.2 A5 21.sup.(PEGMA500) 56 23 33,800 2.8 A6 25.sup.(PEGMA500) 38 37 18,800 2.8 A7 26.sup.(PEGMA360) 18 56 17,900 3.4 A8 37.sup.(HEMA) 44 19 9,500 1.6

(6) In the table, PEGMA500 is polyethylene glycol methacrylate monomer where the polyethylene glycol segment has a molecular weight of around 500, PEGMA360 is polyethylene glycol methacrylate monomer where the polyethylene glycol segment has a molecular weight of around 360 and HEMA is hydroxyethyl methacrylate. These are examples of compounds of formula (II). C12MA is n-dodecylmethacrylate (or lauryl methacrylate) which is a compound of formula (I); and styrene is styrene, which is a compound of formula (III).

(7) The polymers were tested for electrical conductivity in combination with an anti-static additive (B): B1: Stadis 450 obtained from Innospec Inc.

(8) Electrical conductivity was measured using an Emcee Digital Conductivity Meter (Model 1152). Measurements were made in diesel fuel compositions containing the amounts of (A) and (B) detailed in the table below. The diesel fuel had a sulphur content of <10 ppm by weight and an inherent electrical conductivity of ca. 5 pS.sup.1.

(9) TABLE-US-00002 Anti-static additive Electrical Example Polymer (A) (B) conductivity/pS.sup.1 1 A1 (5 wppm) None 52 2 A1 (50 wppm) None 122 3 A1 (100 wppm) None 145 4 A2 (100 wppm) None 92 5 A3 (100 wppm) None 210 6 A4 (100 wppm) None 194 7 A5 (100 wppm) None 90 8 A6 (100 wppm) None 206 9 A7 (100 wppm) None 95 10 A8 (100 wppm) None 33 11 None B1 (0.5 wppm) 84 12 None B1 (1.0 wppm) 179 13 None B1 (3.0 wppm) 542 14 A1 (5 wppm) B1 (0.5 wppm) 377 15 A1 (50 wppm) B1 (0.5 wppm) 535 16 A1 (100 wppm) B1 (0.5 wppm) 713 17 A2 (50 wppm) B1 (0.5 wppm) 563 18 A2 (100 wppm) B1 (0.5 wppm) 748 19 A3 (50 wppm) B1 (0.5 wppm) 629 20 A3 (100 wppm) B1 (0.5 wppm) 1033 21 A4 (50 wppm) B1 (0.5 wppm) 627 22 A4 (100 wppm) B1 (0.5 wppm) 939 23 A5 (50 wppm) B1 (0.5 wppm) 436 24 A5 (100 wppm) B1 (0.5 wppm) 646 25 A6 (50 wppm) B1 (0.5 wppm) 625 26 A6 (100 wppm) B1 (0.5 wppm) 944 27 A7 (50 wppm) B1 (0.5 wppm) 517 28 A7 (100 wppm) B1 (0.5 wppm) 609 29 A8 (50 wppm) B1 (0.5 wppm) 165 30 A8 (100 wppm) B1 (0.5 wppm) 187 31 A1 (5 wppm) B1 (1.0 wppm) 585 32 A1 (50 wppm) B1 (1.0 wppm) 1045 33 A1 (100 wppm) B1 (1.0 wppm) 1172 34 A1 (5 wppm) B1 (3.0 wppm) 995 35 A8 (100 wppm) B1 (3.0 wppm) 892

(10) As can be seen in the table above, all polymers (A) tested were able to provide the diesel fuel with improvements in electrical conductivity when used alone (Examples 1-10). As would be expected, the anti-static additive B1 also provided the diesel fuel with improvements in electrical conductivity when used alone. However, the combined effect of the polymers (A) and the anti-static additive was, in all cases, greatly in excess of that which would be predicted from the individual contributions of each material taken alone. This synergistic behaviour allows a lower amount of the anti-static additive to be used to provide the same or better electrical conductivity. For example, the electrical conductivity attributable to 3.0 wppm of B1 can be achieved using only 0.5 wppm of B1 if combined with 50 wppm of A1 (c.f. Ex 13 & Ex 15); or combined with 50 wppm of A2 (c.f. Ex 13 & Ex 17); or combined with 50 wppm of A3 (c.f. Ex 13 & Ex 19); or combined with 50 wppm of A4 (c.f. Ex 13 & Ex 21); or combined with 100 wppm of A5 (c.f. Ex 13 & Ex 24); or combined with 50 wppm of A6 (c.f. Ex 13 & Ex 25). The amount of expensive B1 can thus be reduced by a factor of 6. As another example, the electrical conductivity attributable to 3.0 wppm of B1 can be achieved using only 1.0 wppm of B1 if combined with just 5 wppm of A1 (c.f. Ex 13 & Ex 31). So a three-fold reduction in the amount of B1 needed can be gained through the use of a very small amount of A1.