United States Patent (19) 11 Patent Number: 4,737,159

Phillips (45) Date of Patent: Apr. 12, 1988

54 CORROSION INHIBITOR FOR LIQUID 3,687,644 8/1972 Delafield et al. ....................... 44/56
FUELS 3,704,109 11/1972 Newman et al. ..... ... 44/66
3,707,362 12/1972 Zimmerman et al. ... 44/72
(75) Inventor: Tayman A. Phillips, Pennsville, N.J. 3,720,615 3/1973 Izumi et al. .......... ... 252/33
(73) Assignee: E. I. Du Pont de Nemours and 3,894,849 7/1975 Polss ......... ... 44/66
Company, Wilmington, Del. 3,925,030 12/1975 Garth .... ... 44/56
3,977,994 8/1976 Geiser ... 252/392
21 Appl. No.: 625,912 4,128,403 12/1978 Honnen ......... ... 44/71
4,173,456 11/1979 Scheule et al. ... 44/66
(22) Filed: Jun. 29, 1984 4,185,594 1/1980 Perilstein ................................ 44/53
4,208, 190 6/1980 Malec ...................................... 44/53
(51) Int. Cl." .............................................. COL 01/02 4,214,876 7/1980 Garth et al. ... 44/66
(52) U.S. Cl. ........................................... 44/53; 44/70; 4,242,099 12/1980 Malec ............ ... 44/53
44/71; 44/72; 44/73; 252/390; 252/392; 4,426,208 1/1984 Perilstein .. ... 44/70
252/394; 252/396 4,440,545 4/1984 Weidig ...... ... 44/70
58 Field of Search ................... 44/70, 66, 53,56, 63, 4,448,586 5/1984 Weidig. ... 44/55
44/71, 73; 252/390, 392,394, 396 4,511,367 4/1985 Knapp ..................................... 44/56
56) References Cited Primary Examiner-William R. Dixon, Jr.
U.S. PATENT DOCUMENTS Assistant Examiner-Margaret B. Medley
Attorney, Agent, or Firm-Craig H. Evans
2,181,121 11/1939 Downing ................................ 44/73
2,181,122 11/1939 Downing ............................ 252/403 57 ABSTRACT
2,284,267 5/1942 Downing .... A corrosion inhibitor for use in liquid hydrocarbon
2,657,982 11/1953 Hill et al. ... fuels or gasoline oxygenate blends is disclosed. The
2,667,408 1/1954 Kleinholz ... corrosion inhibitor contains from 35 to 70 wt % of a
2,813,080 1 1/1957 Bartlett ........... 44/73 monoalkenylsuccinic acid wherein the alkenyl group
2,922,708 1/1960 Lindstron et al. ..................... 44/66
2,993,772 7/1961 Stromberg .............................. 44/70 has 8 to 18 carbon atoms, from about 30 to 65 wt % of
3,071,451 1/1963 Schmerling ............................. 44/73 an aliphatic or cycloaliphatic amine containing 2 to 12
3,282,836 11/1966 Miller et al. 44/70 carbon atoms and up to 50 wt % of total solvents con
3,342,570 9/1967 Kautsky ...... 44/69 sisting of aromatic hydrocarbons and alcohols of 1 to 4
3,346,354 10/1967 Kautsky ...... 44/63 carbons per molecule.
3,421,867 1/1969 Heisler et al. The corrosion inhibitor can also be used in inhibited
3,447,918 9/1969 Amick ..................................... 44/70
3,454,381 7/1969 Eckert ..................................... 44/66 alcohol compositions such as those used in gasoline
3,516,806 9/1970 Malec ...... oxygenate blends.
3,560,173 2/1971 Coffey .....
3,561,936 2/1971 Eckert ..................................... 44/58 19 Claims, No Drawings
 1.
4,737,159
2
is substantially free of nitrogen-containing cyclic
CORROSION INHIBITOR FOR LIQUID FUELS groups and is of the formula
BACKGROUND OF THE INVENTION H R
1. Field of the Invention
The present invention relates to a corrosion inhibitor
composition, an inhibitor-solvent concentrate of the wherein R is selected from H and
inhibitor composition in a solvent consisting of aromatic
hydrocarbons and/or alcohols, and concentrates of the 10
inhibitor composition or inhibitor-solvent concentrate O
with detergents, metal deactivators and gasoline antiox R1-C-,
idants. The invention also relates to an inhibited alcohol
containing the inhibitor composition, the inhibitor-sol at least two R groups are
vent concentrate, or concentrates with detergents, 5
metal deactivators and/or gasoline antioxidants. The O
invention further relates to the use of a concentrate of
the corrosion inhibitor and a polymerized unsaturated R1-C
aliphatic monocarboxylic acid, alone and together with
detergents, metal deactivators and gasoline antioxidants 20 R is C9-12 saturated or unsaturated aliphatic hydro
in gasoline oxygenate blends. carbyl, n is 2 or 3 and x is 2-6;
Corrosion inhibitors are used in fuels to prevent cor (2) 10 to 30 mg/liter of a metal deactivator such as a
rosion in storage tanks and pipelines. The corrosion condensation product of salicylaldehyde and an
problem in storage and pipeline systems usually stems aliphatic diamine, particularly N,N'-bis(salicyli
from water contamination, but, in the case of gasoline 25 dene-1,2-diaminopropane);
oxygenate blends, also stems from acidic impurities in (3) 80 to 250 mg/liter of a N,N'-di(sec. alkyl)-p-
the oxygenate. Corrosion inhibitors intended for use in phenylenediamine type gasoline antioxidant;
fuel systems must be effective in very small quantities so (4) 35 to 100 mg/liter of at least one polymerized
as to avoid adverse effects such as adding to the gum unsaturated aliphatic monocarboxylic acid having
component of the fuel and so as to to minimize costs. 30 16 to 18 carbons per molecule, particularly a poly
Additionally, the corrosion inhibitor, in the amounts merized tall oil fatty acid such as is commercially
employed, must not emulsify water. available.
2. Prior Art The present invention further relates to the use in
U.S. Pat. No. 3,894,849 discloses gasoline containing 35
gasoline oxygenate blends consisting of the following
an acylated polyalkylene polyamine as a detergent, concentrations (expressed in milligrams of additive per
anticing, antirust agent which also exhibits lower en liter of gasoline) of additives:
gine detergent properties. (1) 40 to 12.5 mg/liter of monoalkenylsuccinic acid
U.S. Pat. No. 4,214,876 discloses a corrosion inhibitor and, an aliphatic or cycloaliphatic amine contain
for hydrocarbon fuels comprising a polymerized unsat ing 2 to 12 carbons and, optionally, a hydrocarbon
urated aliphatic carboxylic acid having about 16-18 solvent consisting of an aromatic hydrocarbon, an
carbon atoms and a monoalkenylsuccinic acid wherein alcohol containing 1 to 4 carbon atoms or mixtures
the alkenyl group contains 8-18 carbon atoms. thereof and, optionally;
U.S. Pat. No. 4,426,208 discloses a corrosion inhibitor (2) 1.7 to 5.0 mg/liter of at least one polymerized
for gasohol comprising at least one polymerized unsatu 45 unsaturated aliphatic monocarboxylic acid having
rated aliphatic carboxylic acid having from about 16 to 16 to 18 carbons per molecule, particularly a poly
18 carbon atoms per molecule and an aliphatic dicar merized tall oil fatty acid such as is commercially
boxylic acid having from 2 to about 10 carbon atoms. available and, optionally;
U.S. Pat. No. 4,440,545 discloses a corrosion inhibitor (3) 0.5 to 1.5 mg/liter of a N,N'-bis(salicylidene
for gasohol comprising a hydrocarbyl succinic acid or 50 polyamine), a condensation product of salicylalde
anhydride having from about 8-30 carbon atoms. hyde and an aliphatic diamine, particularly N,N'-
SUMMARY OF THE INVENTION bis(salicylidene-1,2-diaminopropane) and, option
ally;
The present invention relates to a corrosion inhibitor (4) 5.0 to 17.5 mg/liter of an acylated polyalkylene
for hydrocarbon fuels or hydrocarbon fuels containing 55
one or more alcohols. The corrosion inhibitor com polyamine which is substantially free of nitrogen
prises 35 to 70 wt % of a monoalkenylsuccinic acid in containing cyclic groups and is of the formula
which the alkenyl group contains 8 to 18 carbon atoms,
from 30 to 65 wt % of an aliphatic or cycloaliphatic H R
amine containing 2 to 12 carbon atoms and optionally 60
up to 50 wt % of solvents consisting of aromatic hydro
carbons and alcohols of 1 to 4 carbons. wherein R is selected from H and
The present invention also relates to an inhibited
alcohol of 1 to 4 carbons containing 80 to 250 mg of one O
or more of the corrosion inhibitors noted above per liter 65
of alcohol, and optionally R1-C-,
(1) 100 to 350 mg/liter of a detergent such as a gener
ally liquid, acylated polyalkylene polyamine which at least two R groups are
 4,737,159
3 4.
phenylenediamine and N,N'-di(1,4-dimethylpentyl)-p-
O phenylenediamine.
Rl- The corrosion inhibitor composition and its various
concentrates may be blended in alcohols (to be used in
making gasoline-oxygenate blends) in the following
R is C9-21 saturated or unsaturated aliphatic hydro concentrations (expressed in milligrams of additive per
carbyl, n is 2 or 3 and x is 2-6, and optionally; liter of alcohol);
(5) 4.0 to 12.5 mg/liter of a N,N'-di(sec. alkyl)-p- (1) 80 to 250 mg/liter of the corrosion inhibitor com
phenylenediamine type antioxidant. position of the monoalkenylsuccinic acid, aliphatic
DETAILED DESCRIPTION 10 or cycloaliphatic amine and, optionally, the aro
matic hydrocarbon or alcohol and, optionally;
The monoalkenylsuccinic acids contemplated for use (2) 100 to 350 mg/liter of a generally liquid, acylated
herein are well known in the art. These acids are readily polyalkylene polyamine which is substantially free
prepared by the condensation of an olefin with maleic of nitrogen containing cyclic groups and is of the
anhydride followed by hydrolysis (see U.S. Pat. Nos. 15 formula
2,133,734 and 2,741,597). Suitable monoalkenylsuccinic
acids include octenylsuccinic acid, decenylsuccinic H R
acid, undecenylsuccinic acid, dodecenylsuccinic acid,
pentadecenylsuccinic acid, octadecenylsuccinic acid
and isomers thereof having alkenyl groups of various 20
hydrocarbon structures. The preferred monoalkenyl wherein R is selected from H and
succinic acid is dodecenylsuccinic acid, most preferably
dodecenylsuccinic acid prepared from propylene tetra O
ne.
R1-C-,
The amines useful in the present invention are ali 25
phatic and cycloaliphatic amines (containing 2 to 12 at least two R groups are
carbon atoms) of the formula RR2NR3 where R and
R2 are alkyl or alkylene groups, and R3 is an alkyl group O
or hydrogen. R1 and R2 may be cojoined and may be
hydrocarbons or heterocyclic containing an oxygen or 30 R1-C,
other nitrogen atoms. The preferred amines are N,N-
dimethylcyclohexylamine, morpholine and triethanol R is C9-21 saturated or unsaturated aliphatic hydro
amine. carbyl, n is 2 or 3 and x is 2-6 (U.S. Pat. No.
Optionally, the corrosion inhibitor of the present 3,894,849) and, optionally;
invention contains a solvent consisting of an aromatic 35 (3) 10 to 30 mg/liter of N,N'-bis(salicylidene-polya
hydrocarbon and alcohols of 1 to 4 carbons per mole mine), a condensation product of salicylaldehyde
cule, preferably xylene and methanol. and aliphatic diamines, particularly N,N'-bis(-
The corrosion inhibitor composition may be com - salicylidene-1,2-diaminopropane) and, optionally;
bined with detergents such as a acylated polyalkylene (4) 80 to 250 mg/liter of a N,N'-di(sec. alkyl)-p-
polyamine which is substantially free of nitrogen con phenylenediamine and, optionally;
taining cyclic groups and is of the formula (5) 35 to 100 mg/liter of at least one polymerized
unsaturated aliphatic monocarboxylic acid having
H R 16 to 18 carbons per molecule, particularly a poly
merized tall oil fatty acid such as is commercially
45 available.
The hydrocarbon fuels into which the compositions
wherein R is selected from H and of this invention are incorporated to provide corrosion
inhibiting characteristics are normally liquid hydrocar
O bon fuels boiling in the range of about 20-375 C. and
Rl-C-, 50 include motor gasolines, aviation gasolines, kerosenes,
diesel fuels, and fuel oils. The hydrocarbon fuel compo
at least two R groups are sitions containing the compositions of this invention as
corrosion inhibitors may also contain conventional ad
O
ditives such as antiknock compounds, antioxidants,
l 55 metal deactivators, other corrosion inhibitors, antistatic
Rl-C, agents, anticing agents, detergents, dispersants, thermal
stabilizers, dyes and the like.
R is C9-21 saturated or unsaturated aliphatic hydro The hydrocarbon fuel may also contain small propor
carbyl, n is 2 or 3 and x is 2-6, preferably wherein n is tions, e.g., 1 to 10 vol%, of one or more octane-boost
2, x is 4 and R' is C17 (see U.S. Pat. No. 3,894,849); metal 60 ing and fuel-extending oxygenates such as a C1-C4 alco
deactivators such as N,N'-bis(salicylidene-polyamines), hol, exemplified by methanol, ethanol, isopropyl alco
condensation products of salicylaldehyde and aliphatic hol, n-butanol and tertiary-butyl alcohol and/or a terti
diamines, particularly 1,2-diaminopropane which yields ary-alkyl alkyl ether, exemplified by tertiary-butyl
N,N'-bis(salicylidene-1,2-diaminopropane) (see U.S. methyl ether and tertiary-amyl methyl ether.
Pat. Nos. 2,181,121, 2,181,122, 2,284,267, 2,813,080 and 65 The hydrocarbon fuel/oxygenate blends sometimes
3,071,451); and gasoline antioxidants such as N,N'-di contain corrosive, e.g., acidic byproducts of the pro
sec. alkyl)-p-phenylenediamine, particularly N,N'-di(- cesses used to make the oxygenate component. Some
sec. butyl)-p-phenylenediamine, N,N'-di(isopropyl)-p- times the blends, although initially free of corrosive
 5
4,737,159
6
components, develop acidity in storage, particularly xylene is prepared. This is identified as corrosion inhibi
over extended periods of time. The corrosion inhibitor tor C.
compositions of the invention are especially effective in Antirust Evaluation
such corrosive fuel blends. They function by substan
tially different mechanisms when performing as a corro Antirust performances of the compositions of this
sion inhibitor in these gasoline oxygenate blends than invention were determined according to NACE (Na
when in fuel oil where water bottoms are the primary tional Association of Corrosion Engineers) Standard
problem. As an inhibitor in fuel oil water bottoms, the TM-01-72, "Antirust Properties of Petroleum Products
amine component forms a polar salt with the organic Pipeline Cargoes'. The test method is essentially the
acid inhibitor and acts to transport the inhibitor into the 10 ASTM D665 method modified to determine antirust
water phase. As an inhibitor in gasoline-oxygenate properties of gasolines and distillate fuels in movement
blend systems, the amine component acts by neutraliz through product pipelines. The method involves in
ing acidic impurities in the oxygenate, thus allowing the mersing a cylindrical steel specimen in the test fuel,
organic acid inhibitor to be effective. 15
which is stirred 4 hours at 38 C. Distilled water is
The compositions of the invention incorporated into added to the test fuel after the first half hour. The an
hydrocarbon fuels in the range of about 0.0002-0.002 tirust rating is based on the portion of the test specimen
percent by weight (0.5-5 pounds per thousand barrels, that has changed after the 4 hours and is expressed using
ptb) provide satisfactory corrosion-inhibiting proper the following rating scale:
ties. Concentrations higher than about 0.002% can be 20
used but do not appear to provide further benefits. The Rating Proportion of Test Surface Rusted
prefered concentration range is about 0.0003-0.002 per
cent by weight (0.75-5 ptb), the more preferred range is A
B++
None
about 0.0006-0.0018 percent by weight (1.5-4.5 ptb). Less than 0.1% (2 or 3 spots of no
more than 1 mm diameter)
The corrosion-inhibitor compositions of the inven 25 Less than 5%
tion can be added to the hydrocarbon fuels by any
means known in the art for incorporating small quanti
ties of additives into hydrocarbon fuels. The compo
nents can be added separately or they can be combined
D-
E
5-25%
25-50%
50-75%
75-100%

and added together. It is convenient to utilize the pres 30

ent compositions as concentrates, that is, as concen Ordinarily a rating of B+ or B is adequate to control
trated solutions in suitable solvents. When used as a corrosion in active pipeline, although a rating of A is
concentrate, the additive composition will contain obviously more desirable.
about 50-85% by weight, of a combination of the com Corrosion inhibitor A is tested in gasohol formed of
ponents and about 15-50% by weight of a solvent. The 35 90 volume percent RE-117B Ref. Gasoline which is
preferred concentrate will have about 55-80% by commercially available, having the following proper
weight of the combination and about 20-45% by weight ties:
of solvent. The most preferred concentrate will have
about 55-75% by weight of the combination and about ASTM D 287 Gravity API 60 F 62.8
25-45% of solvent. ASTM D 287 Density lb/gal 60 F 6.06
Suitable solvents are normally liquid organic com ASTM D 323 Reid Vapor Pressure, lb 12.6
pounds boiling in the hydrocarbon fuel boiling range, ASTM D 86 Distillation, F
particularly hydrocarbons and alcohols, and include Initial Boiling Point 79
50%. Recovered 206
hexane, cyclohexane, heptane, octane, isooctane, ben End Point 400
Zene, toluene, xylene, methanol, ethanol, propanol, bu 45
tanol, gasolines, jet fuels, fuel oils and the like. Mixtures
of solvents can also be used. The preferred solvent is a and 10 volume percent 200 proof ethanol denatured by
mixture of lower alcohols and aromatic hydrocarbons. 5% UL Gasoline. The results are reported in Table I.
EXAMPLES TABLE I
50
Concentration NACE
Example 1 Additive lb/1000 bbl Rust Rating
A solution containing 56.7 wt % "Acintol' FA-7002 Control 0 E 95
which is a polymerized tall oil fatty acid, 13.3 wt % A.
A
0.5
1.0
C 30
B20
dodecenylsuccinic acid and 30 wt % mixed xylenes. 55 A 2.0 A0
One part of N,N-dimethylcyclohexylamine is added to
three parts of the solution prepared above to form cor
rosion inhibitor A. Corrosion inhibitors A, B and C are tested in RE
117B Reference Gasoline and the results are reported in
Example 2 60
Table II.
A solution containing 22.8 wt % dodecenylsuccinic TABLE II
acid, 36.3 wt % triethanolamine, 25.5 wt % methanol Concentration NACE
and 15.4 wt % xylene is prepared. This is identified as Additive b/1000 bbl Rust Rating
corrosion inhibitor B. Control O E85
65 A 1 B 15
Example 3 B B 4
A solution of 38.3 wt % dodecenylsuccinic acid, 18.9 C 1 A0
wt % morpholine, 22.5 wt % methanol and 20.3 wt %
 4,737,159
7
Corrosion inhibitors are tested in a difficult to treat
Diesel Fuel P82-30 which is commercially available, O
having the following properties: R1-C,
ASTM D 287 Gravity API 60 F 36 R is C9-21 saturated or unsaturated aliphatic hydro
ASTM D 287 Density ib/gal 60 F 7.2.2
carbyl, n is 2 or 3 and x is 2-6, wherein the ratio of the
ASTM D 86 Distiilation, F
Initial Boiling Point 370
composition of (i) to the composition of claim 2 is from
50%. Recovered 43 about 0.53:1 to 1.4:1.
End Point 666 O 9. The composition of claim 8 wherein, in composi
tion (i), n is 2, x is 4 and R' is C17.
The results are reported in Table III. 10. A composition comprising the composition of
claim 2 and (i) a composition of a N,N'-di(sec. alkyl)-p-
TABLE III phenylenediamine, wherein the ratio of the composition
Concentration NACE 5 of (i) to the composition of claim 2 is from about 0.42:1
Additive b/000 bbl Rust Rating to 2.0:1.
Control E90
D 50
11. The composition of claim 10 wherein composition
B20 (i) is of the group N,N'-di(sec. butyl)-p-phenylenedia
B20 mine, N,N'-di(isopropyl)-p-phenylenediamine, or N,N'-
B+ 3 di(1,4-dimethylpentyl)-p-phenylenediamine.
A0
AO
12. A composition comprising the corrosion inhibitor
composition of claim 1, composition (i) of claim 8, com
position (i) of claim 10 and (i) a composition of N,N'-
I claim: 25 bis(salicylidene-polyamine), wherein the ratio of the
1. A corrosion inhibitor composition for liquid hydro composition (i) of claim 8 to the composition (i) of claim
carbon fuels containing 1.0 to 10 volume percent of one 10 to the composition (i) of this claim to the composi
or more alcohols comprising, by weight, tion of claim 1 is from about 0.53:0.42:0.08:1 to
(a) about 35% to 70% of at least one monoalkenylsuc 14:20:0.25:1.
cinic acid in which the alkenyl group has 8 to 18 30 13. An inhibited alcohol composition for use in mak
carbons; and w ing gasoline-oxygenate blends containing an alcohol of
(b) about 30% to 65% of an aliphatic or cycloali 1 to 4 carbon atoms and about 80 to 250 mg of the
phatic amine containing 2 to 12 carbon atoms in a composition of claim 1 per liter of alcohol.
hydrocarbon solvent consisting of an aromatic 14. The inhibited alcohol composition of claim 13
hydrocarbon, an alcohol containing 1 to 4 carbon 35 wherein the alcohol is methanol.
atoms, or mixture thereof, the ratio of the hydro 15. An inhibited alcohol composition comprising the
carbon solvent to the total of (a) and (b) being composition of claim 13 and from about 35 to 100 mg of
about 15:85 to 50:50.
2. The composition of claim 1 wherein the amine is
a composition of at least one polymerized unsaturated
selected from the group consisting of N,N-dimethylcy aliphatic monocarboxylic acid having 16 to 18 carbon
clohexylamine, morpholine or triethanolamine. atoms per liter of alcohol.
3. The composition of claim 2 wherein the monoalk 16. The inhibited alcohol composition of claim 15
enylsuccinic acid is dodecenylsuccinic acid. wherein the polymerized unsaturated aliphatic mono
4. The composition of claim 3 wherein the amine is carboxylic acid is a polymerized tall oil fatty acid.
triethanolamine. 45 17. A gasoline oxygenate blend containing about 4 to
5. The composition of claim 3 wherein the amine is line. 12.5 mg of the composition of claim 1 per liter of gaso
morpholine.
6. The composition of claim 3 wherein the amine is part18.ofA the gasoline oxygenate blend containing about one
composition of claim 15 or 16 to 20 parts
N,N-dimethylcyclohexylamine. 50 gasoline.
7. The composition of claim 2 wherein the solvent is 19. A composition comprising
a mixture of methanol and xylene.
8. A composition comprising the composition of (a) the corrosion inhibitor of claim 1;
claim 2 and (i) a composition which is generally liquid, (b) a composition which is generally liquid, acylated
acylated polyalkylene polyamine which is substantially 5 polyalkylene polyamine which is substantially free
free of nitrogen containing cyclic groups and is of the of nitrogen containing cyclic groups and is of the
formula formula

H R

R1-C-N-(CHN).H 60

wherein R is selected from H and wherein R is selected from H and

O
65
Rl-C-, R1-C,
at least two R groups are at least two R groups are
 4,737,159
9 10
of N,N'-di(sec. butyl)-p-phenylenediamine, N,N'-
O di(isopropyl)-p-phenylenediamine, and N,N'-
R- di(1,4-dimethylpentyl)-p-phenylenediamine; and
5 (d) a composition of N,N'-bis(salicylidene-1,2,-
and R is C17 saturated or unsaturated aliphatic hy- diaminopropane wherein the ratio of b:c:d:a is from
drocarbyl; about 0.53:0.42:0.08:1 to about 1.4:2.0:0.25:1.
(c) a composition selected from the group consisting k . . k at

10

15

20

25

30

35

40

45

50

55

60

65