U.S. patent application number 10/444333 was filed with the patent office on 2004-11-25 for low emission diesel lubricant with improved corrosion protection.
This patent application is currently assigned to Chevron Oronite Company LLC. Invention is credited to Kleijwegt, Peter, Spala, Eugene, Van Dam, Willem, Van Leeuwen, Jeroen.
Application Number | 20040235682 10/444333 |
Document ID | / |
Family ID | 33098025 |
Filed Date | 2004-11-25 |
United States Patent
Application |
20040235682 |
Kind Code |
A1 |
Van Dam, Willem ; et
al. |
November 25, 2004 |
Low emission diesel lubricant with improved corrosion
protection
Abstract
The present invention provides engine lubricants for low
emission diesel engines featuring low levels of ash, sulfur and
phosphorus. Specifically, this invention provides a low emission
diesel lubricant comprising from about 0 wt. % to about 1.2 wt. %
ash; from about 0.1 wt. % to about 0.5 wt. % sulfur; and from about
0.02 wt. % to about 0.1 wt. % phosphorus. Said lubricant may also
comprise a novel unsulfurized, carboxylate-containing additive for
lubricating oils, comprising a mixture of alkaline earth metal
salts (hydrocarbyl phenate/hydrocarbyl salicylate) and a reduced
amount of unreacted hydrocarbyl phenols, in which said hydrocarbyl
salicylate is primarily single-aromatic-ring hydrocarbyl
salicylate. The invention also provides a method for producing said
additive and said LEDL.
Inventors: |
Van Dam, Willem; (Novato,
CA) ; Spala, Eugene; (Fairfield, CA) ;
Kleijwegt, Peter; (Heinenoord, NL) ; Van Leeuwen,
Jeroen; (Barendrecht, NL) |
Correspondence
Address: |
CHEVRON TEXACO CORPORATION
P.O. BOX 6006
SAN RAMON
CA
94583-0806
US
|
Assignee: |
Chevron Oronite Company LLC
Chevron Oronite Technology B.V.
|
Family ID: |
33098025 |
Appl. No.: |
10/444333 |
Filed: |
May 22, 2003 |
Current U.S.
Class: |
508/192 ;
508/506; 508/586 |
Current CPC
Class: |
C10M 2215/28 20130101;
C10N 2030/45 20200501; C10M 2207/142 20130101; C10M 163/00
20130101; C10M 2207/144 20130101; C10N 2060/14 20130101; C10N
2030/04 20130101; C10N 2030/43 20200501; C10M 2215/064 20130101;
C10N 2030/42 20200501; C10N 2030/12 20130101; C10N 2040/252
20200501; C10N 2030/50 20200501 |
Class at
Publication: |
508/192 ;
508/506; 508/586 |
International
Class: |
C10M 141/00 |
Claims
What is claimed is:
1. A low emission diesel lubricant composition comprising: a major
amount of a base oil of lubricating viscosity; a hydroxy-aromatic
surfactant-based detergent-dispersant additive containing less than
40 wt. % free hydrocarbyl phenol; a dispersant; and a wear
inhibitor, wherein said composition contains: from about 0 wt. % to
about 1.2 wt. % ash; from about 0.1 wt. % to about 0.5 wt. %
sulfur; and from about 0.02 wt. % to about 0.1 wt. %
phosphorus.
2. The low emission diesel lubricant composition of claim 1 wherein
said composition further comprises a corrosion inhibitor.
3. The low emission diesel lubricant composition of claim 2 wherein
said additive is unsulfurized.
4. The low emission diesel lubricant composition of claim 3 wherein
said additive is a carboxylate-containing additive.
5. The low emission diesel lubricant composition of claim 4 wherein
said additive further comprises: (a) from 10 to 50% alkaline earth
metal hydrocarbyl phenate; (b) from 15 to 60% alkaline earth metal
single-aromatic-ring hydrocarbyl salicylate; and (c) from 0% to 50%
organic diluent.
6. The low emission diesel lubricant composition of claim 5 wherein
from about 1.8 wt. % to about 5.5 wt. % of said composition
consists of said additive.
7. The low emission diesel lubricant composition of claim 6
wherein: said dispersant is a borated dispersant; and said wear
inhibitor is a metal dithiophosphate.
8. The low emission diesel lubricant composition of claim 7 wherein
said composition contains: from about 1.0 wt. % to about 4.0 wt. %
of said borated dispersant; from about 0.2 wt. % to about 1.1 wt. %
of said wear inhibitor; and from about 0 wt. % to about 0.5 wt. %
of said corrosion inhibitor.
9. The low emission diesel lubricant composition of claim 8
wherein: said dispersant is a succinimide; said wear inhibitor is
zinc dithiophosphate; and said corrosion inhibitor is a neutralized
terephthalic acid.
10. The low emission diesel lubricant composition of claim 9
further comprising: from about 3.0 wt. % to about 8.0 wt. %
non-borated dispersant; from about 0.6 wt. % to about 1.4 wt. %
calcium-sulfonate; from about 0.1 wt. % to about 0.5 wt. %
molybdenum anti-oxidant; from about 0 wt. % to about 1.0 wt. %
phenolic anti-oxidant; from about 0.1 wt. % to about 1.0 wt. %
aminic anti-oxidant; from about 0 wt. % to about 6.0 wt. %
dispersant olefin-copolymer; and from about 0 to about 25 ppm foam
inhibitor.
11. A low emission diesel lubricant composition comprising: a major
amount of a base oil of lubricating viscosity; a hydroxy-aromatic
surfactant-based detergent-dispersant additive containing less than
40 wt. % free hydrocarbyl phenol; a dispersant; and a wear
inhibitor, wherein said composition contains: less than 1.0 wt. %
ash; less than 0.3 wt. % sulfur; and less than 0.08 wt. %
phosphorus.
12. The low emission diesel lubricant composition of claim 11
wherein said composition further comprises a corrosion
inhibitor.
13. The low emission diesel lubricant composition of claim 12
wherein said additive is unsulfurized.
14. The low emission diesel lubricant composition of claim 13
wherein said additive is a carboxylate-containing additive.
15. The low emission diesel lubricant composition of claim 14
wherein said additive further comprises: (a) from 10 to 50%
alkaline earth metal hydrocarbyl phenate; (b) from 15 to 60%
alkaline earth metal single-aromatic-ring hydrocarbyl salicylate;
and (c) from 0% to 50% organic diluent.
16. The low emission diesel lubricant composition of claim 15
wherein from about 1.8 wt. % to about 5.5 wt. % of said composition
consists of said additive.
17. The low emission diesel lubricant composition of claim 16
wherein: said dispersant is a borated dispersant; and said wear
inhibitor is a metal dithiophosphate.
18. The low emission diesel lubricant composition of claim 17
wherein said composition contains: from about 1.0 wt. % to about
4.0 wt. % of said borated dispersant; from about 0.2 wt. % to about
1.1 wt. % of said wear inhibitor; and from about 0 wt. % to about
0.5 wt. % of said corrosion inhibitor.
19. The low emission diesel lubricant composition of claim 18
wherein: said dispersant is a succinimide; said wear inhibitor is
zinc dithiophosphate; and said corrosion inhibitor is a neutralized
terephthalic acid.
20. The low emission diesel lubricant composition of claim 19
further comprising: from about 3.0 wt. % to about 8.0 wt. %
non-borated dispersant; from about 0.6 wt. % to about 1.4 wt. %
calcium-sulfonate; from about 0.1 wt. % to about 0.5 wt. %
molybdenum anti-oxidant; from about 0 wt. % to about 1.0 wt. %
phenolic anti-oxidant; from about 0.1 wt. % to about 1.0 wt. %
aminic anti-oxidant; from about 0 wt. % to about 6.0 wt. %
dispersant olefin-copolymer; and from about 0 to about 25 ppm foam
inhibitor.
21. A low emission diesel lubricant composition comprising: a major
amount of a base oil of lubricating viscosity; a hydroxy-aromatic
surfactant-based detergent-dispersant additive containing less than
40 wt. % free hydrocarbyl phenol; a dispersant; and a wear
inhibitor, wherein said composition contains: from about 0.4 wt. %
to about 1.0 wt. % ash; from about 0.05 wt. % to about 0.3 wt. %
sulfur; and from about 0.02 wt. % to about 0.08 wt. %
phosphorus.
22. The low emission diesel lubricant composition of claim 21
wherein said composition further comprises a corrosion
inhibitor.
23. The low emission diesel lubricant composition of claim 22
wherein said additive is unsulfurized.
24. The low emission diesel lubricant composition of claim 23
wherein said additive is a carboxylate-containing additive.
25. The low emission diesel lubricant composition of claim 24
wherein said additive further comprises: (a) from 10 to 50%
alkaline earth metal hydrocarbyl phenate; (b) from 15 to 60%
alkaline earth metal single-aromatic-ring hydrocarbyl salicylate;
and (c) from 0% to 50% organic diluent.
26. The low emission diesel lubricant composition of claim 25
wherein from about 1.8 wt. % to about 5.5 wt. % of said composition
consists of said additive.
27. The low emission diesel lubricant composition of claim 26
wherein: said dispersant is a borated dispersant; and said wear
inhibitor is a metal dithiophosphate.
28. The low emission diesel lubricant composition of claim 27
wherein said composition contains: from about 1.0 wt. % to about
4.0 wt. % of said borated dispersant; from about 0.2 wt. % to about
1.1 wt. % of said wear inhibitor; and from about 0 wt. % to about
0.5 wt. % of said corrosion inhibitor.
29. The low emission diesel lubricant composition of claim 28
wherein: said dispersant is a succinimide; said wear inhibitor is
zinc dithiophosphate; and said corrosion inhibitor is a neutralized
terephthalic acid.
30. The low emission diesel lubricant composition of claim 29
further comprising: from about 3.0 wt. % to about 8.0 wt. %
non-borated dispersant; from about 0.6 wt. % to about 1.4 wt. %
calcium-sulfonate; from about 0.1 wt. % to about 0.5 wt. %
molybdenum anti-oxidant; from about 0 wt. % to about 1.0 wt. %
phenolic anti-oxidant; from about 0.1 wt. % to about 1.0 wt. %
aminic anti-oxidant; from about 0 wt. % to about 6.0 wt. %
dispersant olefin-copolymer; and from about 0 to about 25 ppm foam
inhibitor.
31. A low emission diesel lubricant composition comprising: a major
amount of a base oil of lubricating viscosity; a hydroxy-aromatic
surfactant-based detergent-dispersant additive containing less than
40 wt. % free hydrocarbyl phenol; a dispersant; and a wear
inhibitor, wherein said composition contains: from about 0.4 wt. %
to about 1.0 wt. % ash; from about 0.05 wt. % to about 0.15 wt. %
sulfur; and from about 0.02 wt. % to about 0.08 wt. %
phosphorus.
32. A low emission diesel lubricant composition comprising: a major
amount of a base oil of lubricating viscosity; a dispersant; a wear
inhibitor; and an effective corrosion inhibiting amount of an
unsulfurized carboxylate-containing additive prepared by a method
comprising: (a) neutralization of hydrocarbyl phenols using an
alkaline earth base in the presence of a promoter, to produce a
hydrocarbyl phenate; (b) carboxylation of the hydrocarbyl phenate
obtained in step (a) using carbon dioxide under carboxylation
conditions sufficient to convert at least 20 mole % of the starting
hydrocarbyl phenols to hydrocarbyl salicylate; and (c) separation
of at least about 10% of thestarting hydrocarbyl phenols from the
product produced in step (b) to produce said additive, wherein said
composition contains: from about 0 wt. % to about 1.2 wt. % ash;
from about 0.1 wt. % to about 0.5 wt. % sulfur; and from about 0.02
wt. % to about 0.1 wt. % phosphorus.
33. The low emission diesel lubricant composition of claim 32,
wherein said hydrocarbyl salicylate comprises single-aromatic-ring
hydrocarbyl salicylate and double-aromatic-ring hydrocarbyl
salicylate wherein the mole ratio of single aromatic-ring
hydrocarbyl salicylate to double-aromatic-ring hydrocarbyl
salicylate is at least 8:1.
34. The low emission diesel lubricant composition of claim 32,
wherein, in said separation step, at least about 30% of the
starting hydrocarbyl phenols is separated from the product produced
in step (b) to produce said additive.
35. The low emission diesel lubricant composition of claim 32,
wherein, in said separation step, up to 55% of the starting
hydrocarbyl phenols is separated from the product produced in step
(b) to produce said additive.
36. The low emission diesel lubricant composition of claim 32,
wherein, in said separation, step about 45% to about 50% of the
starting hydrocarbyl phenols is separated from the product produced
in step (b) to produce said additive.
37. The low emission diesel lubricant composition of claim 32,
wherein, in said separation step, said starting hydrocarbyl phenols
are removed by distillation.
38. The low emission diesel lubricant composition of claim 37,
wherein, in said separation step, at least about 30% of the
starting hydrocarbyl phenols is separated from the product produced
in step (b) to produce said additive.
39. The low emission diesel lubricant composition of claim 37,
wherein, in said separation step, up to 55% of the starting
hydrocarbyl phenols is separated from the product produced in step
(b) to produce said additive.
40. The low emission diesel lubricant composition of claim 37,
wherein, in said separation step, about 45% to about 50% of the
starting hydrocarbyl phenols is separated from the product produced
in step (b) to produce said additive.
41. The low emission diesel lubricant composition of claim 37,
wherein said distillation is accomplished via falling film
distillation, wiped film evaporator distillation, or short path
distillation.
42. The low emission diesel lubricant composition of claim 41,
wherein said distillation is carried out at temperatures ranging
from about 150.degree. C. to about 250.degree. C. and at pressures
from about 0.1 to about 4 mbar.
43. The low emission diesel lubricant composition of claim 41,
wherein said distillation is carried out at temperatures ranging
from about 190.degree. C. to about 230.degree. C. and at pressures
from about 0.5 to about 3 mbar.
44. The low emission diesel lubricant composition of claim 41,
wherein said distillation is carried out at temperatures ranging
from about 195.degree. C. to about 225.degree. C., and at a
pressure of about 1 to about 2 mbar.
45. The low emission diesel lubricant composition of claim 32,
wherein an effective viscosity improving amount of organic diluent
is added to said additive.
46. The low emission diesel lubricant composition of claim 32,
wherein, in said neutralization step: (a) said neutralization
operation is carried out in the presence of at least one carboxylic
acid containing from one to four carbon atoms, and in the absence
of alkali base, dialcohol, and monoalcohol; and (b) said
neutralization operation is carried out at a temperature of at
least 200.degree. C.; (c) the pressure is reduced gradually below
atmospheric in order to remove the water of reaction, in the
absence of any solvent that may form an azeotrope with water; (d)
said hydrocarbyl phenols contain up to 85% of linear hydrocarbyl
phenol in mixture with at least 15% of branched hydrocarbyl phenol
in which the branched hydrocarbyl radical contains at least nine
carbon atoms; and (e) the quantities of reagents used correspond to
the following molar ratios: (1) alkaline earth base/hydrocarbyl
phenol of 0.2:1 to 0.7:1; and (2) carboxylic acid/hydrocarbyl
phenol of from 0.01:1 to 0.5:1.
47. The low emission diesel lubricant composition of claim 32
wherein said composition further comprises a corrosion
inhibitor.
48. The low emission diesel lubricant composition of claim 47
wherein from about 1.8 wt. % to about 5.5 wt. % of said lubricant
consists of said additive.
49. The low emission diesel lubricant composition of claim 48
wherein: said dispersant is a borated dispersant; and said wear
inhibitor is a metal dithiophosphate.
50. The low emission diesel lubricant composition of claim 49
wherein said composition contains: from about 1.0 wt. % to about
4.0 wt. % of said borated dispersant; from about 0.2 wt. % to about
1.1 wt. % of said wear inhibitor; and from about 0 wt. % to about
0.5 wt. % of said corrosion inhibitor.
51. The low emission diesel lubricant composition of claim 50
wherein: said dispersant is a succinimide; said wear inhibitor is
zinc dithiophosphate; and said corrosion inhibitor is a neutralized
terephthalic acid.
52. The low emission diesel lubricant composition of claim 51
further comprising: from about 3.0 wt. % to about 8.0 wt. %
non-borated dispersant; from about 0.6 wt. % to about 1.4 wt. %
calcium-sulfonate; from about 0.1 wt. % to about 0.5 wt. %
molybdenum anti-oxidant; from about 0 wt. % to about 1.0 wt. %
phenolic anti-oxidant; from about 0.1 wt. % to about 1.0 wt. %
aminic anti-oxidant; from about 0 wt. % to about 6.0 wt. %
dispersant olefin-copolymer; and from about 0 to about 25 ppm foam
inhibitor.
53. A low emission diesel lubricant composition comprising: a major
amount of a base oil of lubricating viscosity; a dispersant; a wear
inhibitor; and an effective corrosion inhibiting amount of an
unsulfurized carboxylate-containing additive prepared by a method
comprising: (a) neutralization of hydrocarbyl phenols using an
alkaline earth base in the presence of a promoter, to produce a
hydrocarbyl phenate; (b) carboxylation of the hydrocarbyl phenate
obtained in step (a) using carbon dioxide under carboxylation
conditions sufficient to convert at least 20 mole % of the starting
hydrocarbyl phenols to hydrocarbyl salicylate; and (c) separation
of at least about 10% of the starting hydrocarbyl phenols from the
product produced in step (b) to produce said additive, wherein said
composition contains: less than 1.0 wt. % ash; less than 0.3 wt. %
sulfur; and less than 0.08 wt. % phosphorus.
54. The low emission diesel lubricant composition of claim 53
wherein said composition further comprises a corrosion
inhibitor.
55. The low emission diesel lubricant composition of claim 54
wherein from about 1.8 wt. % to about 5.5 wt. % of said lubricant
consists of said additive.
56. The low emission diesel lubricant composition of claim 55
wherein: said dispersant is a borated dispersant; and said wear
inhibitor is a metal dithiophosphate.
57. The low emission diesel lubricant composition of claim 56
wherein said composition contains: from about 1.0 wt. % to about
4.0 wt. % of said borated dispersant; from about 0.2 wt. % to about
1.1 wt. % of said wear inhibitor; and from about 0 wt. % to about
0.5 wt. % of said corrosion inhibitor.
58. The low emission diesel lubricant composition of claim 57
wherein: said dispersant is a succinimide; said wear inhibitor is
zinc dithiophosphate; and said corrosion inhibitor is a neutralized
terephthalic acid.
59. The low emission diesel lubricant composition of claim 58
further comprising: from about 3.0 wt. % to about 8.0 wt. %
non-borated dispersant; from about 0.6 wt. % to about 1.4 wt. %
calcium-sulfonate; from about 0.1 wt. % to about 0.5 wt. %
molybdenum anti-oxidant; from about 0 wt. % to about 1.0 wt. %
phenolic anti-oxidant; from about 0.1 wt. % to about 1.0 wt. %
aminic anti-oxidant; from about 0 wt. % to about 6.0 wt. %
dispersant olefin-copolymer; and from about 0 to about 25 ppm foam
inhibitor.
60. A low emission diesel lubricant composition comprising: a major
amount of a base oil of lubricating viscosity; a dispersant; a wear
inhibitor; and an effective corrosion inhibiting amount of an
unsulfurized carboxylate-containing additive prepared by a method
comprising: (a) neutralization of hydrocarbyl phenols using an
alkaline earth base in the presence of a promoter, to produce a
hydrocarbyl phenate; (b) carboxylation of the hydrocarbyl phenate
obtained in step (a) using carbon dioxide under carboxylation
conditions sufficient to convert at least 20 mole % of the starting
hydrocarbyl phenols to hydrocarbyl salicylate; and (c) separation
of at least about 10% of the starting hydrocarbyl phenols from the
product produced in step (b) to produce said additive, wherein said
composition contains: from about 0.4 wt. % to about 1.0 wt. % ash;
from about 0.05 wt. % to about 0.3 wt. % sulfur; and from about
0.02 wt. % to about 0.08 wt. % phosphorus.
61. The low emission diesel lubricant composition of claim 60
wherein said composition further comprises a corrosion
inhibitor.
62. The low emission diesel lubricant composition of claim 61
wherein from about 1.8 wt. % to about 5.5 wt. % of said lubricant
consists of said additive.
63. The low emission diesel lubricant composition of claim 62
wherein: said dispersant is a borated dispersant; and said wear
inhibitor is a metal dithiophosphate.
64. The low emission diesel lubricant composition of claim 63
wherein said composition contains: from about 1.0 wt. % to about
4.0 wt. % of said borated dispersant; from about 0.2 wt. % to about
1.1 wt. % of said wear inhibitor; and from about 0 wt. % to about
0.5 wt. % of said corrosion inhibitor.
65. The low emission diesel lubricant composition of claim 64
wherein: said dispersant is a succinimide; said wear inhibitor is
zinc dithiophosphate; and said corrosion inhibitor is a neutralized
terephthalic acid.
66. The low emission diesel lubricant composition of claim 65
further comprising: from about 3.0 wt. % to about 8.0 wt. %
non-borated dispersant; from about 0.6 wt. % to about 1.4 wt. %
calcium-sulfonate; from about 0.1 wt. % to about 0.5 wt. %
molybdenum anti-oxidant; from about 0 wt. % to about 1.0 wt. %
phenolic anti-oxidant; from about 0.1 wt. % to about 1.0 wt. %
aminic anti-oxidant; from about 0 wt. % to about 6.0 wt. %
dispersant olefin-copolymer; and from about 0 to about 25 ppm foam
inhibitor.
67. A low emission diesel lubricant composition comprising: a major
amount of a base oil of lubricating viscosity; a dispersant; a wear
inhibitor; and an effective corrosion inhibiting amount of an
unsulfurized carboxylate-containing additive prepared by a method
comprising: (a) neutralization of hydrocarbyl phenols using an
alkaline earth base in the presence of a promoter, to produce a
hydrocarbyl phenate; (b) carboxylation of the hydrocarbyl phenate
obtained in step (a) using carbon dioxide under carboxylation
conditions sufficient to convert at least 20 mole % of the starting
hydrocarbyl phenols to hydrocarbyl salicylate; and (c) separation
of at least about 10% of the starting hydrocarbyl phenols from the
product produced in step (b) to produce said additive, wherein said
composition contains: from about 0.4 wt. % to about 1.0 wt. % ash;
from about 0.05 wt. % to about 0.15 wt. % sulfur; and from about
0.02 wt. % to about 0.08 wt. % phosphorus.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to engine lubricants for low
emission diesel engines equipped with exhaust gas after-treatment
systems that can be sensitive to lubricant constituents. Some of
these types of after-treatment systems are known to be sensitive to
fuel and lubricant constituents. In order to ensure the durability
of these after-treatment systems, lubricants have been developed
that feature low levels of ash, sulfur, and phosphorus. Ash, sulfur
and phosphorus are present in many conventional lubricant additives
such as detergents and zinc-dithiophosphates. To meet the
requirement of maximum ash, sulfur and phosphorus levels, the low
emission diesel lubricant ("LEDL") of the present invention has
been developed using new components and component combinations.
[0002] Known LEDLs, which meet the requirement of maximum ash,
sulfur and phosphorus levels, have been unable to meet minimum
corrosion protection requirements. The new LEDL additive
formulation described in this invention solves the corrosion
problem while maintaining good performance in other areas. The
formulation can be used in a finished oil blended with Group 1, 2,
3, or 4 base stocks or combinations thereof. The finished oil using
this formulation may or may not contain a viscosity modifier, pour
point depressant, and any ester added for solubility.
BACKGROUND OF THE INVENTION
[0003] There have heretofore been efforts to reduce the amount of
sulfur in lubricating oil compositions.
[0004] For example, JP11-181463 teaches a gear oil that contains
(a) 0.5-3 mass % of primary zinc dithiophosphoric acid, (b) 1.2-4
mass % of alkaline earth metal type detergent-dispersant, (c)
1.5-10 mass % of bis type alkenyl succinic acid imide or its
derivative, (d) 0.3-3 mass % of amine salt of phosphate ester (e)
0.05-5 mass % of one or more sulfur compounds, and (f) a base oil
that has less than 0.1 wt-% sulfur.
[0005] In order to further reduce the sulfur content in lubricating
oil compositions, non-sulfur containing detergents may be employed.
The preparation of both sulfur containing and non-sulfur containing
hydrocarbyl phenates and hydrocarbyl salicylates is well known in
the art.
[0006] U.S. Pat. No. 3,036,971 discloses preparing detergent
dispersant additives based on sulfurized alkylphenates of high
basicity alkaline earth metals. These additives are prepared by
sulfurization of an alkylphenol, neutralization of the sulfurized
alkylphenol with an alkaline earth metal base, then
super-alkalization by carbonation of the alkaline earth metal base
dispersed in the sulfurized alkylphenate.
[0007] French patent 1,563,557 discloses detergent additives based
on sulfurized calcium alkylsalicylates. These additives are
prepared by carboxylation of a potassium alkylphenate, exchange
with calcium chloride, then sulfurization of the calcium
alkylsalicylate obtained with sulfur in the presence of lime, a
carboxylic acid and an alkylene glycol or alkyl ether of alkylene
glycol.
[0008] French patent application 2,625,220 discloses superalkalized
detergent-dispersant additives based on alkylphenates and
alkylsalicylates. These additives are prepared by neutralization of
an alkylphenol with an alkaline earth metal base in the presence of
an acid and a solvent, distillation of the solvent, carboxylation,
sulfurization and superalkalization by sulfur and an alkaline earth
metal base in the presence of glycol and solvent, followed by
carbonation and filtration.
[0009] U.S. Pat. No. 5,808,145 discloses a process that is able to
improve substantially the performance of
alkylphenate/alkylsalicylate additives, particularly in the tests
relating to foaming, compatibility and dispersion in a new oil, and
in the tests of stability towards hydrolysis. This process
comprises neutralization with alkaline earth metal base of a
mixture of linear and branched alkylphenols in the presence of a
carboxylic acid, carboxylation by the action of carbon dioxide of
the alkylphenate, followed by sulfurization and super-alkalization,
then carbonation, distillation, filtration, and degassing in
air.
[0010] European Patent Application Publication No. 0933417
discloses an unsulfurized, alkali metal-free detergent-dispersant
additive, comprising a mixture of alkaline earth metal salts
(alkylphenate/alkylsalicylate) and unreacted alkylphenol. This
additive improves antioxidant properties, high temperature deposit
control, and black sludge control.
[0011] U.S. Pat. Nos. 6,162,770 and 6,262,001 teach an
unsulfurized, alkali metal-free, detergent-dispersant composition
having from 40% to 60% alkylphenol, from 10% to 40% alkaline earth
alkylphenate, and from 20% to 40% alkaline earth
single-aromatic-ring alkylsalicylate, and a process for preparing
the same. This composition may have an alkaline earth
double-aromatic-ring alkylsalicylate as long as the mole ratio of
single-ring alkylsalicylate to double-aromatic-ring alkylsalicylate
is at least 8:1. This composition may be produced by the three-step
process involving neutralization of alkylphenols, carboxylation of
the resulting alkylphenate, and filtration of the product of the
carboxylation step. The detergent-dispersant produced by the method
can be used in an engine lubricating composition to improve
antioxidant properties, high temperature deposit control, and black
sludge control.
[0012] It is desirable to find a low sulfur, ash and phosphorus
lubricant with superior corrosion performance. The LEDL of the
current invention is a low sulfur, ash, and phosphorus lubricant
with superior corrosion performance.
SUMMARY OF THE INVENTION
[0013] The present invention provides a novel low emission diesel
lubricant, or LEDL, comprising low levels of ash, sulfur and
phosphorus. Preferably, said LEDL also contains an unsulfurized,
carboxylate-containing hydroxy-aromatic surfactant-based
detergent-dispersant additive comprising a mixture of alkaline
earth metal salts (hydrocarbyl phenate/hydrocarbyl salicylate) and
a reduced amount of unreacted hydrocarbyl phenols. The present
invention also relates to additive packages, concentrates and
finished oil compositions comprising the same. Most preferably, it
relates to said LEDL in which said hydrocarbyl salicylate is
primarily single-aromatic-ring hydrocarbyl salicylate.
[0014] In a preferred embodiment, the present invention also
relates to a novel LEDL comprising an unsulfurized,
carboxylate-containing hydroxy-aromatic surfactant-based
detergent-dispersant additive for lubricating oils, which additive
comprises a mixture of alkaline earth metal salts (hydrocarbyl
phenate/hydrocarbyl salicylate) and a reduced amount of unreacted
hydrocarbyl phenols, as well as additive packages, concentrates and
finished oil compositions comprising the same. Specifically, said
preferred embodiment relates to an LEDL comprising said
unsulfurized, carboxylate-containing additive containing said
mixture in which said hydrocarbyl salicylate is primarily
single-aromatic-ring hydrocarbyl salicylate. This additive improves
antioxidant properties, high temperature deposit control, BN
retention, corrosion control and black sludge control in
lubricating oils. This invention is also directed, in part, to
methods of preparing and using said novel LEDL.
[0015] The LEDL of the present invention may have, for example, the
following composition: a major amount of a base oil of lubricating
viscosity, a hydroxy-aromatic surfactant-based detergent-dispersant
additive containing less than 40 weight percent ("wt. %") free
hydrocarbyl phenol; a dispersant; a wear inhibitor; and from about
0 wt. % to about 1.2 wt. % ash (as measured by ASTM D874); from
about 0.1 wt. % to about 0.5 wt. % sulfur; and from about 0.02 wt.
% to about 0.1 wt. % phosphorus. Preferably, the LEDL of the
present invention comprise a major amount of a base oil of
lubricating viscosity and from about 0.4 wt. % to about 1.0 wt. %
ash; from about 0.05 wt. % to about 0.3 wt. % sulfur; and from
about 0.02 wt. % to about 0.08 wt. % phosphorus. More preferably,
said LEDL comprises a major amount of a base oil of lubricating
viscosity and less than 1.0 wt. % ash; less than 0.3 wt. % sulfur;
and less than 0.08 wt. % phosphorus. Most preferably, said LEDL
comprises a major amount of a base oil of lubricating viscosity and
from about 0.4 wt. % to about 1.0 wt. % ash; from about 0.05 wt. %
to about 0.15 wt. % sulfur; and from about 0.02 wt. % to about 0.08
wt. % phosphorus.
[0016] In one embodiment, the LEDL also comprises a corrosion
inhibitor. In a preferred embodiment, the hydroxy-aromatic
surfactant-based detergent-dispersant additive is unsulfurized.
Preferably, said additive is a carboxylate-containing additive.
More preferably, said additive comprises from 10 to 50% alkaline
earth metal hydrocarbyl phenate; from 15 to 60% alkaline earth
metal single-aromatic-ring hydrocarbyl salicylate; and from 0% to
50% organic diluent.
[0017] In a preferred embodiment, the LEDL comprises a major amount
of a base oil of lubricating viscosity and from about 0 wt. % to
about 1.2 wt. % ash; from about 0.1 wt. % to about 0.5 wt. %
sulfur; from about 0.02 wt. % to about 0.1 wt. % phosphorus; and
from about 1.8 wt. % to about 5.5 wt. % of an unsulfurized,
carboxylate-containing, hydroxy-aromatic, surfactant-based,
detergent-dispersant additive comprising: (a) less than 40%
hydrocarbyl phenol; (b) from 10 to 50% alkaline earth metal
hydrocarbyl phenate; (c) from 15 to 60% alkaline earth metal
single-aromatic-ring hydrocarbyl salicylate; and (d) from 0% to 50%
organic diluent.
[0018] In another embodiment, said LEDL further comprises from
about 1.0 wt. % to about 4.0 wt. % borated dispersant; from about
0.2 wt. % to about 1.1 wt. % wear inhibitor; and from about 0 wt. %
to about 0.5 wt. % corrosion inhibitor. More preferably, said
dispersant is a succinimide; said wear inhibitor is zinc
dithiophosphate; and said corrosion inhibitor is a neutralized
terephthalic acid. Most preferably, said LEDL also comprises from
about 3.0 wt. % to about 8.0 wt. % non-borated dispersant; from
about 0.6 wt. % to about 1.4 wt. % calcium-sulfonate; from about
0.1 wt. % to about 0.5 wt. % molybdenum anti-oxidant; from about 0
wt. % to about 1.0 wt. % phenolic anti-oxidant; from about 0.1 wt.
% to about 1.0 wt. % aminic anti-oxidant; from about 0 wt. % to
about 6.0 wt. % dispersant olefin-copolymer; and from about 0 to
about 25 ppm foam inhibitor.
[0019] Preferably, the LEDL of the present invention will contain
no sulfur-containing detergent.
[0020] In one embodiment, the hydroxy-aromatic surfactant-based
detergent-dispersant additive comprises from 0 to 35% free
hydrocarbyl phenol; preferably from 0 to 30% free hydrocarbyl
phenol; more preferably from 0 to 20% free hydrocarbyl phenol; most
preferably from 0 to 15% free hydrocarbyl phenol.
[0021] The LEDL of the present invention may advantageously
comprise a major amount of a base oil of lubricating viscosity and
from about 0.4 wt. % to about 1.0 wt. % ash; from about 0.2 wt. %
to about 0.4 wt. % sulfur; from about 0.04 wt. % to about 0.08 wt.
% phosphorus; and from about 2.7 wt. % to about 5.5 wt. % of an
unsulfurized carboxylate-containing additive comprising: (a) less
than 40% hydrocarbyl phenol; (b) from 10 to 50% alkaline earth
metal hydrocarbyl phenate; (c) from 15 to 60% alkaline earth metal
single-aromatic-ring hydrocarbyl salicylate; and (d) from 0% to 50%
organic diluent. Said LEDL may further comprise from about 1.0 wt.
% to about 4.0 wt. % borated dispersant; and from about 0 wt. % to
about 0.5 wt. % corrosion inhibitor. Most preferably, said LEDL
also comprises from about 3.0 wt. % to about 8.0 wt. % non-borated
dispersant; from about 0.6 wt. % to about 1.4 wt. %
calcium-sulfonate; from about 0.2 wt. % to about 1.1 wt. % zinc
dithiophosphate; from about 0.1 wt. % to about 0.5 wt. % molybdenum
anti-oxidant; from about 0 wt. % to about 1.0 wt. % phenolic
anti-oxidant; from about 0.1 wt. % to about 1.0 wt. % aminic
anti-oxidant; from about 0 wt. % to about 6.0 wt. % dispersant
olefin-copolymer; and from about 0 to about 25 ppm foam inhibitor.
Preferably, the sulfur content of said LEDL is from about 0.1 wt. %
to about 0.3 wt. %.
[0022] The present invention also provides a LEDL composition
comprising a major amount of a base oil of lubricating viscosity; a
dispersant; a wear inhibitor; and an effective corrosion inhibiting
amount of an unsulfurized carboxylate-containing hydroxy-aromatic
surfactant-based detergent-dispersant additive prepared by a method
comprising: (a) neutralization of hydrocarbyl phenols using an
alkaline earth base in the presence of a promoter, to produce a
hydrocarbyl phenate; (b) carboxylation of the hydrocarbyl phenate
obtained in step (a) using carbon dioxide under carboxylation
conditions sufficient to convert at least 20 mole % of the starting
hydrocarbyl phenols to hydrocarbyl salicylate; and (c) separation
of at least about 10% of the starting hydrocarbyl phenols from the
product produced in step (b) to produce said additive, wherein said
composition contains: from about 0 wt. % to about 1.2 wt. % ash;
from about 0.1 wt. % to about 0.5 wt. % sulfur; and from about 0.02
wt. % to about 0.1 wt. % phosphorus.
[0023] Preferably, said promoter comprises at least one carboxylic
acid containing from one to four carbon atoms, and said
neutralization step is carried out in the absence of alkali base,
in the absence of dialcohol, and in the absence of monoalcohol. The
neutralization step is followed by carboxylation of the hydrocarbyl
phenate produced in the neutralization step; and separation of the
starting hydrocarbyl phenols from the product of the carboxylation
step.
[0024] In the above described preparation of the unsulfurized
carboxylate-containing hydroxy-aromatic surfactant-based
detergent-dispersant additive, the hydrocarbyl phenols may comprise
linear and/or branched hydrocarbyl constituents. For example, the
hydrocarbyl phenols may be made up entirely of linear hydrocarbyl
phenol, entirely of branched hydrocarbyl phenol, or a mixture of
both. Preferably, the hydrocarbyl phenols contain up to 85% of
linear hydrocarbyl phenol in mixture with at least 15% of branched
hydrocarbyl phenol in which the branched hydrocarbyl radical
contains at least nine carbon atoms. More preferably, the
hydrocarbyl phenols are alkylphenols which contain from 35% to 85%
of linear alkylphenol in mixture with from 15% to 65% of branched
alkylphenol. The ratio of branched versus linear alkylphenol is
given by weight. Preferably, the linear hydrocarbyl radical
contains 12 to 40 carbon atoms, more preferably from 18 to 30
carbon atoms, and, if branched hydrocarbyl phenols are present, the
branched hydrocarbyl radical contains at least 9 carbon atoms,
preferably from 9 to 24 carbon atoms, more preferably 10 to 15
carbon atoms.
[0025] Preferably, the alkaline earth base is selected from the
group consisting of calcium oxide, calcium hydroxide, magnesium
oxide, and mixtures thereof.
[0026] Preferably, the carboxylic acid is a mixture of formic acid
and acetic acid, more preferably a 50/50 by weight mixture of
formic and acetic acid.
[0027] Preferably, the neutralization step is carried out at a
temperature of at least 200.degree. C., more preferably at least
215.degree. C. The pressure is reduced gradually below atmospheric
in order to remove the water of reaction, in the absence of any
solvent that may form an azeotrope with water. Preferably, the
quantities of reagents used correspond to the following molar
ratios:
[0028] (1) alkaline earth base/alkylphenol of from 0.2:1 to 0.7:1,
more preferably from 0.3:1 to 0.5:1; and
[0029] (2) carboxylic acid/alkylphenol of from 0.01:1 to 0.5:1,
more preferably from 0.03:1 to 0.15:1.
[0030] In one embodiment, the neutralization step is carried out at
a temperature of at least 240.degree. C. with a gradual reduction
in pressure below atmospheric so as to reach a pressure of no more
than 7,000 Pa (70 mbars) at 240.degree. C.
[0031] The hydrocarbyl phenate obtained in the neutralization step
is carboxylated in order to convert at least 20 mole % of the
starting hydrocarbyl phenols to hydrocarbyl salicylate using carbon
dioxide under carboxylation conditions. Preferably, at least 22
mole % of the starting hydrocarbyl phenols is converted, and this
conversion occurs at a temperature between 180.degree. C. and
240.degree. C., under a pressure within the range of from above
atmospheric pressure to 15.times.10.sup.5 Pa (15 bars) for a period
of one to eight hours.
[0032] More preferably, the starting hydrocarbyl phenols are
alkylphenols and at least 25 mole % of the starting alkylphenols is
converted to alkylsalicylate using carbon dioxide at a temperature
equal to or greater than 200.degree. C., under a pressure of
4.times.10.sup.5 Pa (4 bars).
[0033] The hydrocarbyl salicylate produced in the carboxylation
step carboxylation step may comprise both single-aromatic-ring
hydrocarbyl salicylate and double-aromatic-ring hydrocarbyl
salicylate. Preferably, the mole ratio of single-aromatic-ring
hydrocarbyl salicylate to double-aromatic-ring hydrocarbyl
salicylate is at least 8:1.
[0034] Preferably, the product of the carboxylation step is then
filtered to remove any sediment formed in the carboxylation
step.
[0035] The product of the carboxylation step is then subjected to a
separation procedure such as solvent extraction, distillation,
membrane filtration, and the like wherein at least about 10% of the
starting hydrocarbyl phenols are separated from the product of the
carboxylation step. Preferably, at least about 30% up to about 55%
of the starting hydrocarbyl phenols are separated. More preferably,
at least about 45% to about 50% of the starting hydrocarbyl phenols
are separated from the product of the carboxylation step.
[0036] Once the starting hydrocarbyl phenols are separated from the
product of the carboxylation step, said hydrocarbyl phenols may
advantageously be recycled to be used as starting materials in the
process of the present invention or in any other process.
[0037] Preferably, the separation step is performed via
distillation, more preferably via falling film distillation or
short path distillation, most preferably via wiped film evaporator
distillation. Said distillation is carried out at a temperature of
from about 150.degree. C. to about 250.degree. C. and at a pressure
of about 0.1 to about 4 mbar; more preferably from about
190.degree. C. to about 230.degree. C. and at about 0.5 to about 3
mbar; most preferably from about 195.degree. C. to about
225.degree. C. and at a pressure of about 1 to about 2 mbar.
[0038] Prior to its addition to the LEDL composition of the present
invention, the unsulfurized, carboxylate-containing
hydroxy-aromatic surfactant-based detergent-dispersant additive may
advantageously be blended with an effective viscosity improving
amount of organic diluent. Preferably, enough diluent is added so
that said diluent makes up from about 10% to about 80% by weight of
the blended product. More preferably, said diluent makes up from
about 20% to about 50% by weight of the blended product. Suitable
diluents include Group 1 or Group 2 base oils such as 100N base
oil; organic solvents such as pentane, heptane, benzene, toluene
and the like; and other suitable organic compounds such as
hydrocarbyl phenols which may advantageously be recycled from the
distillation step of the present invention.
[0039] The unsulfurized, carboxylate-containing hydroxy-aromatic
surfactant-based detergent-dispersant additive produced by the
above described method has the following composition:
[0040] (a) less than 40% hydrocarbyl phenol,
[0041] (b) 10% to 50% alkaline earth metal hydrocarbyl phenate,
[0042] (c) 15% to 60% alkaline earth metal single-aromatic-ring
hydrocarbyl salicylate, and
[0043] (d) 0% to 50% organic diluent.
[0044] Said unsulfurized, carboxylate-containing hydroxy-aromatic
surfactant-based detergent-dispersant additive may also comprise an
alkaline earth metal double-aromatic-ring hydrocarbyl salicylate,
but the mole ratio of single-aromatic-ring hydrocarbyl salicylate
to double-aromatic-ring hydrocarbyl salicylate will be at least
8:1.
[0045] The LEDL of the present invention may be used as an engine
lubricating oil composition containing a major part of lubricating
oil, a hydroxy-aromatic surfactant-based detergent-dispersant
additive and preferably at least one other additive. Examples of
other additives that may be used include metal-containing
detergents; ashless dispersants; borated and non-borated
dispersants, including ethylene carbonate treated dispersants; low
overbased ("LOB"), medium overbased ("MOB"), high overbased ("HOB")
and high-high overbased ("HHOB") calcium sulfonates; oxidation
inhibitors, rust inhibitors, demulsifiers, extreme pressure agents,
friction modifiers, multifunctional additives, viscosity index
improvers, pour point depressants, and foam inhibitors.
[0046] In automotive applications, the high temperature deposit
control performance, corrosion control and oxidation inhibition
performance of a lubricating oil can be improved by adding to the
lubricating oil an effective amount of the LEDL composition of the
present invention. Accordingly, the corrosion protection in any
internal combustion engine may be improved by contacting said
engine with the LEDL of the current invention.
DETAILED DESCRIPTION OF THE INVENTION
[0047] In its broadest aspect, the present invention provides a
LEDL composition comprising low levels of ash, sulfur and
phosphorus. Advantageously, said LEDL may contain an unsulfurized,
carboxylate-containing hydroxy-aromatic surfactant-based
detergent-dispersant additive comprising hydrocarbyl phenol,
alkaline earth metal hydrocarbyl phenate, and alkaline earth metal
single-aromatic-ring hydrocarbyl salicylate useful for improving BN
retention, corrosion performance, bulk oxidation, high temperature
deposit control, black sludge control, thermal oxidation stability,
and other properties of a lubricating oil.
[0048] Prior to discussing the invention in further detail, the
following terms will be defined:
Definitions
[0049] As used herein the following terms have the following
meanings unless expressly stated to the contrary:
[0050] The term "hydrocarbyl" means an alkyl or alkenyl group.
[0051] The term "metal" means alkali metals, alkaline earth metals,
or mixtures thereof.
[0052] The term "alkaline earth metal" means calcium, barium,
magnesium, strontium, or mixtures thereof.
[0053] The term "salicylate" means a metal salt of a salicylic
acid.
[0054] The term "alkaline earth metal single-aromatic-ring
hydrocarbyl salicylate" means an alkaline earth metal salt of a
hydrocarbyl salicylic acid, wherein there is only one hydrocarbyl
salicylic anion per each alkaline earth metal base cation.
[0055] The term "alkaline earth metal single-aromatic-ring
alkylsalicylate" means an alkaline earth metal single-aromatic-ring
hydrocarbyl salicylate wherein the hydrocarbyl group is an alkyl
group.
[0056] The term "alkaline earth metal double-aromatic-ring
hydrocarbyl salicylate" means an alkaline earth metal salt of a
hydrocarbyl salicylic acid, wherein there are two hydrocarbyl
salicylic anions per each alkaline earth metal base cation.
[0057] The term "alkaline earth metal double-aromatic-ring
alkylsalicylate" means an alkaline earth metal double-aromatic-ring
hydrocarbyl salicylate wherein the hydrocarbyl groups are alkyl
groups.
[0058] The term "hydrocarbyl phenol" means a phenol having one or
more hydrocarbyl substituents; at least one of which has a
sufficient number of carbon atoms to impart oil solubility to the
phenol.
[0059] The term "alkylphenol" means a phenol having one or more
alkyl substituents, wherein at least one of the alkyl substituents
has a sufficient number of carbon atoms to impart oil solubility to
the phenol.
[0060] The term "phenate" means a metal salt of a phenol.
[0061] The term "hydrocarbyl phenate" means a metal salt of a
hydrocarbyl phenol.
[0062] The term "alkaline earth metal hydrocarbyl phenate" means an
alkaline earth metal salt of a hydrocarbyl phenol.
[0063] The term "alkaline earth metal alkylphenate" means an
alkaline earth metal salt of an alkylphenol.
[0064] The term "phenate-stearate" means a phenate that has been
treated with stearic acid or anhydride or salt thereof.
[0065] The term "long-chain carboxylic acid" means a carboxylic
acid having an alkyl group having an average carbon number of from
13 to 28. The alkyl group may be linear, branched, or mixtures
thereof.
[0066] The term "carboxy-stearate" means an alkaline earth metal
single-aromatic-ring hydrocarbyl salicylate that has been treated
with a long-chain carboxylic acid, anhydride or salt thereof.
[0067] The term "major amount" means at least about 40% by
weight.
[0068] The term "unsulfurized" means containing less than 0.1 wt %
sulfur.
[0069] The term "Base Number" or "BN" refers to the amount of base
equivalent to milligrams of KOH in one gram of sample. Thus, higher
BN numbers reflect more alkaline products, and therefore a greater
alkalinity reserve. The BN of a sample can be determined by ASTM
Test No. D2896 or any other equivalent procedure.
[0070] Unless otherwise specified, all percentages are in weight
percent. 1
[0071] Preparation of an Unsulfurized Carboxylate-Containing
Hydroxy-Aromatic Surfactant-Based Detergent-Dispersant Additive
[0072] A. Neutralization Step
[0073] In the first step, hydrocarbyl phenols are neutralized in
the presence of a promoter. In one embodiment, said hydrocarbyl
phenols are neutralized using an alkaline earth metal base in the
presence of at least one C.sub.1 to C.sub.4 carboxylic acid.
Preferably, this reaction is carried out in the absence of alkali
base, and in the absence of dialcohol or monoalcohol.
[0074] The hydrocarbyl phenols may contain up to 100% linear
hydrocarbyl groups, up to 100% branched hydrocarbyl groups, or both
linear and branched hydrocarbyl groups. Preferably, the linear
hydrocarbyl group, if present, is alkyl, and the linear alkyl
radical contains 12 to 40 carbon atoms, more preferably 18 to 30
carbon atoms. The branched hydrocarbyl radical, if present, is
preferably alkyl and contains at least nine carbon atoms,
preferably 9 to 24 carbon atoms, more preferably 10 to 15 carbon
atoms. In one embodiment, the hydrocarbyl phenols contain up to 85%
of linear hydrocarbyl phenol (preferably at least 35% linear
hydrocarbyl phenol) in mixture with at least 15% of branched
hydrocarbyl phenol.
[0075] The use of an alkylphenol containing at least 35% of
long-chain linear alkylphenol (from 18 to 30 carbon atoms) is
particularly attractive because a long linear alkyl chain promotes
the compatibility and solubility of the additives in lubricating
oils. However, the presence of relatively heavy linear alkyl
radicals in the alkylphenols can make the latter less reactive than
branched alkylphenols, hence the need to use harsher reaction
conditions to bring about their neutralization by an alkaline earth
metal base.
[0076] Branched alkylphenols can be obtained by reaction of phenol
with a branched olefin, generally originating from propylene. They
consist of a mixture of monosubstituted isomers, the great majority
of the substituents being in the para position, very few being in
the ortho position, and hardly any in the meta position. That makes
them relatively more reactive towards an alkaline earth metal base,
since the phenol function is practically devoid of steric
hindrance.
[0077] On the other hand, linear alkylphenols can be obtained by
reaction of phenol with a linear olefin, generally originating from
ethylene. They consist of a mixture of monosubstituted isomers in
which the proportion of linear alkyl substituents in the ortho,
para, and meta positions is more uniformly distributed. This makes
them less reactive towards an alkaline earth metal base since the
phenol function is less accessible due to considerable steric
hindrance, due to the presence of closer and generally heavier
alkyl substituents. Of course, linear alkylphenols may contain
alkyl substituents with some branching which increases the amount
of para substituents and, resultantly, increases the relative
reactivity towards alkaline earth metal bases.
[0078] The alkaline earth metal bases that can be used for carrying
out this step include the oxides or hydroxides of calcium,
magnesium, barium, or strontium, and particularly of calcium oxide,
calcium hydroxide, magnesium oxide, and mixtures thereof. In one
embodiment, slaked lime (calcium hydroxide) is preferred.
[0079] The promoter used in this step can be any material that
enhances neutralization. For example, the promoter may be a
polyhydric alcohol, dialcohol, monoalcohol, ethylene glycol or any
carboxylic acid. Preferably, a carboxylic acid is used. More
preferably, C.sub.1 to C.sub.4-carboxylic acids are used in this
step including, for example, formic, acetic, propionic and butyric
acid, and may be used alone or in mixture. Preferably, a mixture of
acids is used, most preferably a formic acid/acetic acid mixture.
The molar ratio of formic acid/acetic acid should be from 0.2:1 to
100:1, preferably between 0.5:1 and 4:1, and most preferably 1:1.
The carboxylic acids act as transfer agents, assisting the transfer
of the alkaline earth metal bases from a mineral reagent to an
organic reagent.
[0080] The neutralization operation is carried out at a temperature
of at least 200.degree. C., preferably at least 215.degree. C., and
more preferably at least 240.degree. C. The pressure is reduced
gradually below atmospheric in order to distill off the water of
reaction. Accordingly the neutralization should be conducted in the
absence of any solvent that may form an azeotrope with water.
Preferably, the pressure is reduced to no more than 7,000 Pa (70
mbars).
[0081] The quantities of reagents used should correspond to the
following molar ratios:
[0082] (1) alkaline earth metal base/hydrocarbyl phenol of 0.2:1 to
0.7:1, preferably 0.3:1 to 0.5:1; and
[0083] (2) carboxylic acid/hydrocarbyl phenol of 0.01:1 to 0.5:1,
preferably from 0.03:1 to 0.15:1.
[0084] Preferably, at the end of this neutralization step the
hydrocarbyl phenate obtained is kept for a period not exceeding
fifteen hours at a temperature of at least 215.degree. C. and at an
absolute pressure of between 5,000 and 10.sup.5 Pa (between 0.05
and 1.0 bar). More preferably, at the end of this neutralization
step the hydrocarbyl phenate obtained is kept for between two and
six hours at an absolute pressure of between 10,000 and 20,000 Pa
(between 0.1 and 0.2 bar).
[0085] By providing that operations are carried out at a
sufficiently high temperature and that the pressure in the reactor
is reduced gradually below atmospheric, the neutralization reaction
is carried out without the need to add a solvent that forms an
azeotrope with the water formed during this reaction.
[0086] B. Carboxylation Step
[0087] The carboxylation step is conducted by simply bubbling
carbon dioxide into the reaction medium originating from the
preceding neutralization step and is continued until at least 20
mole % of the starting hydrocarbyl phenols is converted to
hydrocarbyl salicylate (measured as salicylic acid by
potentiometric determination). It must take place under pressure in
order to avoid any decarboxylation of the alkylsalicylate that
forms.
[0088] Preferably, at least 22 mole % of the starting hydrocarbyl
phenols is converted to hydrocarbyl salicylate using carbon dioxide
at a temperature of between 180.degree. C. and 240.degree. C.,
under a pressure within the range of from above atmospheric
pressure to 15.times.10.sup.5 Pa (15 bars) for a period of one to
eight hours.
[0089] According to one variant, at least 25 mole % of the starting
hydrocarbyl phenols is converted to hydrocarbyl salicylate using
carbon dioxide at a temperature equal to or greater than
200.degree. C. under a pressure of 4.times.10.sup.5 Pa (4
bars).
[0090] C. Filtration Step
[0091] The product of the carboxylation step may advantageously be
filtered. The purpose of the filtration step is to remove
sediments, and particularly crystalline calcium carbonate, which
might have been formed during the preceding steps, and which may
cause plugging of filters installed in lubricating oil
circuits.
[0092] D. Separation Step
[0093] At least 10% of the starting hydrocarbyl phenol is separated
form the product of the carboxylation step. Preferably, the
separation is accomplished using distillation. More preferably, the
distillation is carried out in a wiped film evaporator at a
temperature of from about 150.degree. C. to about 250.degree. C.
and at a pressure of about 0.1 to about 4 mbar; more preferably
from about 190.degree. C. to about 230.degree. C. and at about 0.5
to about 3 mbar; most preferably from about 195.degree. C. to about
225.degree. C. and at a pressure of about 1 to about 2 mbar. At
least 10% of the starting hydrocarbyl phenol is separated. More
preferably, at least 30% of the starting hydrocarbyl phenol is
separated. Most preferably, up to 55% of the starting hydrocarbyl
phenol is separated. The separated hydrocarbyl phenol may then be
recycled to be used as starting materials in the novel process or
in any other process.
[0094] Unsulfurized, Carboxylate-Containing Hydroxy-Aromatic
Surfactant-Based Detergent-Dispersant Additve
[0095] The unsulfurized, carboxylate-containing hydroxy-aromatic
surfactant-based detergent-dispersant additive formed by the above
process can be characterized by its unique composition, with much
more alkaline earth metal single-aromatic-ring hydrocarbyl
salicylate and less hydrocarbyl phenol than produced by other
routes. When the hydrocarbyl group is an alkyl group, the
unsulfurized, carboxylate-containing additive has the following
composition;
[0096] (a) less than 40% alkylphenol,
[0097] (b) from 10% to 50% alkaline earth metal alkylphenate,
and
[0098] (c) from 15% to 60% alkaline earth metal
single-aromatic-ring alkylsalicylate.
[0099] Unlike alkaline earth metal alkylsalicylates produced by
other processes, this unsulfurized, carboxylate-containing additive
composition can be characterized by having only minor amounts of an
alkaline earth metal double-aromatic-ring alkylsalicylates. The
mole ratio of single-aromatic-ring alkylsalicylate to
double-aromatic-ring alkylsalicylate is at least 8:1.
[0100] Characterization of the Product by Infrared Spectrometry
[0101] Out-of-aromatic-ring-plane C--H bending vibrations were used
to characterize the unsulfurized carboxylate-containing
hydroxy-aromatic surfactant-based detergent-dispersant additive
employed in the present invention.
[0102] Infrared spectra of aromatic rings show strong out-of-plane
C--H bending transmittance band in the 675-870 cm.sup.-1 region,
the exact frequency depending upon the number and location of
substituents. For ortho-disubstituted compounds, transmittance band
occurs at 735-770 cm.sup.-1. For para-disubstituted compounds,
transmittance band occurs at 810-840 cm.sup.-1.
[0103] Infrared spectra of reference chemical structures relevant
to the present invention indicate that the out-of-plane C--H
bending transmittance band occurs at 750.+-.3 cm.sup.-1 for
ortho-alkylphenols, at 760.+-.2 cm.sup.-1 for salicylic acid, and
at 832.+-.3 cm.sup.-1 for para-alkylphenols.
[0104] Alkaline earth alkylphenates known in the art have infrared
out-of-plane C--H bending transmittance bands at 750.+-.3 cm.sup.-1
and at 832.+-.3 cm.sup.-1. Alkaline earth alkylsalicylates known in
the art have infrared out-of-plane C--H bending transmittance bands
at 763.+-.3 cm.sup.-1 and at 832.+-.3 cm.sup.-1.
[0105] The unsulfurized carboxylate-containing hydroxy-aromatic
surfactant-based detergent-dispersant additive employed in the
present invention shows essentially no out-of-plane C--H bending
vibration at 763+3 cm.sup.-1, even though there is other evidence
that alkylsalicylate is present. This particular characteristic has
not been fully explained. However, it may be hypothesized that the
particular structure of the single aromatic ring alkylsalicylate
prevents in some way this out-of-plane C--H bending vibration. In
this structure, the carboxylic acid function is engaged in a cyclic
structure, and thus may generate increased steric hindrance in the
vicinity of the aromatic ring, limiting the free motion of the
neighbor hydrogen atom. This hypothesis is supported by the fact
that the infrared spectrum of the acidified product (in which the
carboxylic acid function is no longer engaged in a cyclic structure
and thus can rotate) has an out-of-plane C--H transmittance band at
763.+-.3 cm.sup.-1.
[0106] The unsulfurized carboxylate-containing hydroxy-aromatic
surfactant-based detergent-dispersant additive employed in the
present invention can thus be characterized by having a ratio of
infrared transmittance band of out-of-plane C--H bending at about
763.+-.3 cm.sup.-1 to out-of-plane C--H bending at 832.+-.3
cm.sup.-1 of less than 0.1:1.
[0107] The unsulfurized, carboxylate-containing hydroxy-aromatic
surfactant-based detergent-dispersant additive formed by the
abovemethod, being non-sulfurized, would provide improved high
temperature deposit control performance over sulfurized products
while meeting the low sulfur requirements for LEDLs. Being
alkali-metal free, this additive can be employed as a
detergent-dispersant in applications, such as marine engine oils,
where the presence of alkali metals have proven to have harmful
effects.
[0108] Hydroxy-Aromatic Surfactant-Based Detergent-Dispersant
Additives
[0109] Hydroxy-aromatic surfactant-based detergent-dispersant
additives are well known in the art. Examples of such additives
include phenates, phenate-carboxylates, salicylates,
carboxy-stearates, and the unsulfurized carboxylate-containing
additive described above.
[0110] Preparation of Phenates
[0111] The phenates which may be used in the present invention are
typically hydrocarbyl substituted phenates in which the hydrocarbyl
substituent or substituents of the phenate are preferably one or
more alkyl group, either branched or unbranched. Suitable alkyl
groups contain from 4 to 50, preferably from 9 to 28 carbon atoms.
Particularly suitable alkyl groups are C.sub.12 groups derivable
from propylene tetramer. The hydrocarbyl substituted phenates are
typically sulfurized.
[0112] According to one preferred embodiment of the present
invention, overbased sulfurized alkylphenates of alkaline earth
metals are prepared by neutralizing a sulfurized alkylphenol with
an alkaline earth base in the presence of a dilution oil, a glycol,
and halide ions, the glycol being present in the form of a mixture
with an alcohol having a boiling point above 150.degree. C.,
removing alcohol, glycol, water, and sediment, carbonating the
reaction medium with CO.sub.2 in the presence of halide ions, and
again removing alcohol, glycol, water, and sediment.
[0113] In another preferred embodiment, an overbased, sulfurized
hydrocarbyl phenate is prepared by a process comprising the steps
of:
[0114] (a) neutralizing a sulfurized alkylphenol with an alkaline
earth base in the presence of a dilution oil, a glycol, and halide
ions, the glycol being present in the form of a mixture with an
alcohol having a boiling point above 150.degree. C.;
[0115] (b) removing alcohol, glycol, and water from the medium,
preferably by distillation;
[0116] (c) removing sediment from the medium, preferably by
filtration;
[0117] (d) carbonating the resultant medium with CO.sub.2 in the
presence of halide ions; and
[0118] (e) removing alcohol, glycol, and water from the medium,
preferably by distillation.
[0119] The alkaline earth bases useful in the above process include
the oxides and hydroxides of barium, strontium, and calcium,
particularly lime. Alcohols with a boiling point above 150.degree.
C. useful in the process include alcohols of C.sub.6 to C.sub.14
such as ethylhexanol, oxoalcohol, decylalcohol, tridecylalcohol;
alkoxyalcohols such as 2-butoxyethanol, 2-butoxypropanol; and
methyl ethers of dipropylene glycol. The amines useful in the
process include polyaminoalkanes, preferably polyaminoethanes,
particularly ethylenediamine, and aminoethers, particularly
tris(3-oxa-6-amino-hexyl)amine. The glycols useful in the process
include alkylene glycols, particularly ethylene glycol. The halide
ions employed in the process are preferably Cl.sup.- ions which may
be added in the form of ammonium chloride or metal chlorides such
as calcium chloride or zinc chloride.
[0120] The dilution oils suitable for use in the above process
include naphthenic oils and mixed oils and preferably paraffinic
oils such as neutral 100 oil. The quantity of dilution oil used is
such that the amount of oil in the final product constitutes from
about 25% to about 65% by weight of the final product, preferably
from about 30% to about 50%.
[0121] The process outlined above is more fully described in U.S.
Pat. No. 4,514,313, which is incorporated by reference into this
application.
[0122] Preparation of Phenate-Carboxylates
[0123] The phenate-carboxylates which may be used in the present
invention are typically hydrocarbyl substituted
phenate-carboxylates in which the hydrocarbyl substituent or
substituents of the phenate are preferably one or more alkyl group,
either branched or unbranched. Suitable alkyl groups contain from 4
to 50, preferably from 9 to 28 carbon atoms. Particularly suitable
alkyl groups are C.sub.12 groups derivable from propylene tetramer.
The hydrocarbyl substituted phenate-carboxylates may be sulfurized
or unsulfurized.
[0124] The overbased hydrocarbyl phenate-carboxylate is prepared
from an overbased hydrocarbyl phenate which has been treated,
either before, during, or subsequent to overbasing, with a
long-chain carboxylic acid (preferably stearic acid), anhydride or
salt thereof. That process comprises contacting a mixture of a
hydrocarbyl phenate, at least one solvent, metal hydroxide, aqueous
metal chloride, and an alkyl polyhydric alcohol containing from one
to five carbon atoms, with carbon dioxide under overbasing reaction
conditions. Using an aqueous metal chloride, instead of a solid
metal chloride, reduces the viscosity of the product. Preferably,
the metals are alkaline earth metals, most preferably calcium.
Preferably, the alkyl polyhydric alcohol is ethylene glycol.
[0125] In a preferred embodiment, the overbased hydrocarbyl
phenate-carboxylate is produced by overbasing a hydrocarbyl phenate
and treating the phenate (before, during, or after overbasing) with
a long-chain carboxylic acid (preferably stearic acid), anhydride
or salt thereof.
[0126] In the overbasing step, a mixture comprising hydrocarbyl
phenate (which can be sulfurized or unsulfurized), at least one
solvent, metal hydroxide, aqueous metal chloride, and an alkyl
polyhydric alcohol containing from one to five carbon atoms is
reacted with carbon dioxide under overbasing reaction conditions.
Overbasing reaction conditions include temperatures of from 250 to
375.degree. F. at approximately atmospheric pressure.
[0127] Preferably, the overbased hydrocarbyl phenate is a
sulfurized alkylphenate. Preferably, the metal is an alkaline earth
metal, more preferably calcium. Preferably, the alkyl polyhydric
alcohol is ethylene glycol.
[0128] The carboxylate treatment (treatment with long-chain
carboxylic acid, anhydride, or salt thereof) can occur before,
during, or after the overbasing step. It is unimportant when the
treatment with long-chain carboxylic acid, anhydride, or salt
thereof occurs relative to the overbasing step.
[0129] The phenate can be sulfurized or unsulfurized. Preferably,
the phenate is sulfurized. If the phenate is sulfurized, the
sulfurization step can occur anytime prior to overbasing. More
preferably, the phenate is sulfurized before the overbasing step
but after the carboxylate treatment.
[0130] The process outlined above is more fully described in U.S.
Pat. No. 5,942,476, which is incorporated by reference into this
application.
[0131] Preparation of Salicylates
[0132] The preparation of salicylates is well known in the art.
Preferred salicylates which may be used in the present invention
include medium and high overbased salicylates including salts of
polyvalent or monovalent metals, more preferably monovalent, most
preferably calcium. As used herein, medium overbased (MOB) is meant
to include salicylates with a TBN of about 31 to 170. High
overbased (HOB) is meant to include salicylates with a TBN from
about 171 to 400. High-high overbased (HHOB) is meant to include
salicylates with a TBN over 400.
[0133] In one embodiment, salicylates may be prepared, for
instance, starting from phenol, ortho-alkylphenol, or
para-alkylphenol, by alkylation, carboxylation and salt formation.
The alkylating agent preferably chosen is an olefin or a mixture of
olefins with more than 12 carbon atoms to the molecule.
Acid-activated clays are suitable catalysts for the alkylation of
phenol and ortho- and para-alkylphenol. The amount of catalyst
employed-is, in general, 1-10 wt %, in particular, 3-7 wt %,
referred to the sum of the amounts by weight of alkylating agent
and phenol to be alkylated. The alkylation may be carried out at
temperatures between 100 and 250.degree. C., in particular, between
125 and 225.degree. C.
[0134] The alkylphenols prepared via the phenol or ortho- or
para-alkylphenol route may be converted into the corresponding
alkylsalicylic acids by techniques well known in the art. For
instance, the alkylphenols are converted with the aid of an
alcoholic caustic solution into the corresponding alkylphenates and
the latter are treated with CO.sub.2 at about 140.degree. C. and a
pressure of 10 to 30 atmospheres. From the alkylsalicylates so
obtained, the alkylsalicylic acids may be liberated with the aid
of, for example, 30% sulfuric acid.
[0135] For the preparation of overbased salicylates, the
alkylsalicylic acids may be treated with an excess amount of a
metal compound, for instance, calcium in the form of
Ca(OH).sub.2.
[0136] For example, the alkylsalicylic acids may be treated with 4
equivalents of calcium in the form of Ca(OH).sub.2 with
introduction of 1.6 equivalents of CO.sub.2.
[0137] The preparation of medium and overbased salicylates is more
fully described in U.S. Pat. No. 4,810,398, and GB Patents
1,146,925; 790,473; and 786,167, which are incorporated by
reference into this application.
[0138] Preparation of Carboxy-Stearates
[0139] The carboxy-stearates which may be used in the present
invention are typically alkaline earth metal single-aromatic-ring
hydrocarbyl salicylates that have been treated with a long-chain
carboxylic acid, anhydride or salt thereof.
[0140] The carboxy-stearate is prepared from a mixture of alkaline
earth metal single-aromatic-ring salicylate, at least one solvent,
and alkaline earth metal hydroxide. The mixture is overbased by
contacting the mixture with carbon dioxide in the presence of an
alkyl polyhydric alcohol, wherein the alkyl group of the alcohol
has from one to five carbon atoms. One such useful alkyl polyhydric
alcohol is ethylene glycol.
[0141] The process outlined above is more fully described in U.S.
Pat. No. 6,348,438, which is incorporated by reference into this
application.
[0142] Base Oil of Lubricating Viscosity
[0143] The base oil of lubricating viscosity used in such
compositions may be mineral oil or synthetic oils of viscosity
suitable for use in the crankcase of an internal combustion engine.
Crankcase base oils ordinarily have a viscosity of about 1300 cSt
at 0.degree. F. (-18.degree. C.) to 3 cSt at 210.degree. F.
(99.degree. C.). The base oils may be derived from synthetic or
natural sources. Mineral oil for use as the base oil in this
invention includes paraffinic, naphthenic and other oils that are
ordinarily used in lubricating oil compositions. Synthetic oils
include both hydrocarbon synthetic oils and synthetic esters.
Useful synthetic hydrocarbon oils include liquid polymers of alpha
olefins having the proper viscosity. Especially useful are the
hydrogenated liquid Qligomers of C.sub.6 to C.sub.12 alpha olefins
such as 1-decene trimer. Likewise, alkyl benzenes of proper
viscosity, such as didodecyl benzene, can be used. Useful synthetic
esters include the esters of monocarboxylic acids and
polycarboxylic acids, as well as mono-hydroxy alkanols and polyols.
Typical examples are didodecyl adipate, penta-erythritol
tetracaproate, di-2-ethylhexyl adipate, dilaurylsebacate, and the
like. Complex esters prepared from mixtures of mono and
dicarboxylic acids and mono and dihydroxy alkanols can also be
used.
[0144] Blends of mineral oils with synthetic oils are also useful.
For example, blends of 10 to 25% hydrogenated 1-decene trimer with
75 to 90% 150 SUS (100.degree. F.) mineral oil make excellent
lubricating oil bases.
[0145] The LEDL of the present invention can be added to Group 1,
2, 3, or 4 base stocks or combinations thereof.
[0146] Detergents
[0147] The LEDL of the present invention has been found to provide
improved bulk oxidation and corrosion control performance when
contacted with an internal combustion engine. Embodiments of the
LEDL may contain detergents.
[0148] Detergents help control varnish, ring zone deposits, and
rust by keeping insoluble particles in colloidal suspension.
Metal-containing (or ash-forming detergents) function both as
detergents to control deposits, and as acid neutralizers or rust
inhibitors, thereby reducing wear and corrosion and extending
engine life. Detergents generally comprise a polar head with a long
hydrophobic tail; with the polar head comprising a metal salt of an
acidic organic compound. The salts may contain a substantially
stoichiometric amount of the metal in which case they are usually
described as normal or neutral salts, and would typically have a
total base number (as measured by ASTM D2896) of from 0 to 10. It
is possible to include large amounts of a metal base by reacting an
excess of a metal compound such as an oxide or hydroxide with an
acidic gas such as carbon dioxide to form an overbased detergent.
Such overbased detergents may have a total base number of about 15
to 30 (low overbased ("LOB")); 31 to 170 (medium overbased ("MOB));
171 to 400 (high overbased ("MOB")); or above 400 (high-high
overbased ("HHOB)).
[0149] Dispersants
[0150] The LEDLs of this invention may comprise one or more
dispersants including nitrogen containing dispersants of the type
generally represented by succinimides (e.g., polyisobutylene
succinic acid/anhydride (PIBSA)-polyamine having a PIBSA molecular
weight of about 700 to 2500). The dispersants may be borated or
non-borated, ashless or ash containing. Lubricating oils of this
invention may comprise about 1 wt. % to about 12 wt. % or more
dispersants.
[0151] Preferred dispersants for this invention comprise one or
more dispersants having an average molecular weight (mw) of about
1000 to about 10,000. Dispersants prepared from polyisobutylene
(PIB) having a mw of about 1000 to about 5000 are such preferred
dispersants.
[0152] A preferred dispersant of this invention may be a one or
more succinimides. The term "succinimide" is understood in the art
to include many of the amide, imide, etc. species that are also
formed by the reaction of a succinic anhydride with an amine and is
so used herein. The predominant product, however, is succinimide
and this term has been generally accepted as meaning the product of
a reaction of an alkenyl- or alkyl-substituted succinic acid or
anhydride with a polyamine. Alkenyl or alkyl succinimides are
disclosed in numerous references and are well known in the art.
Certain fundamental types of succinimides and related materials
encompassed by the term of art "succinimide" are taught in U.S.
Pat. Nos. 2,992,708; 3,018,250; 3,018,291; 3,024,237; 3,100,673;
3,172,892; 3,219,666; 3,272,746; 3,361,673; 3,381,022; 3,912,764;
4,234,435; 4,612,132; 4,747,965; 5,112,507; 5,241,003; 5,266,186;
5,286,799; 5,319,030; 5,334,321; 5,356,552; 5,716,912, the
disclosures of which are hereby incorporated by reference.
[0153] This invention may comprise one or more succinimides, which
may be either a mono, poly, or bis-succinimide. This invention may
comprise lubricating oil involving one or more succinimide
dispersants that have or have not been post treated.
[0154] Borated dispersants useful in the present invention may be
derived from the reaction product of a polyisobutenylsuccinic
anhydride with a polyamine. Preferably, the borated dispersant is
derived from polybutenes having a molecular weight of from 1200 to
1400, most preferably about 1300.
[0155] Ethylene carbonate treated, or EC-treated, dispersants
useful in the present invention may be derived from the reaction
product of a polyisobutenylsuccinic anhydride with a polyamine. The
polyisobutene has a number average molecular weight (M.sub.n) of at
least 1800. Preferably, the EC-treated dispersant is a polybutene
succinimide derived from polybutenes having a molecular weight of
from 2000 to 2400. A prefered EC treated succinimide of this
invention is described in U.S. Pat. Nos. 5,334,321 and
5,356,552.
[0156] Corrosion Inhibitors
[0157] Corrosion inhibitors which may advantageously be used in the
LEDL of this invention are, for example, succinimide salts of one
or more aromatic dicarboxylic acids, and dispersed aromatic
dicarboxylic acid corrosion inhibitors. Preferred aromatic
dicarboxylic acids may comprise one or more terephthalic acids.
[0158] Certain corrosion inhibitors, including dispersed aromatic
dicarboxylic acid corrosion inhibitors, are described, for example,
in U.S. Pat. Nos. 3,287,271; 3,692,681; and 3,374,174, all of which
are incorporated herein in their entirety.
[0159] One embodiment of the dispersed aromatic dicarboxylic acid
corrosion inhibitor may be synthesized by reacting about 1100 to
about 1500, preferably about 1300 molecular weight polyisobutenyl
succinic anhydride (PIBSA) with one or more polyamines, preferably
one or more heavy polyamines (HPA) at an amine/PIBSA CMR of about
0.4 to about 0.6, preferably about 0.45. This produces a reaction
product that may then be reacted with terephthalic acid.
[0160] Another embodiment of the dispersed aromatic dicarboxylic
acid corrosion inhibitor of this invention may be synthesized as
follows. One or more PIBSAs may be reacted with one or more
polyamines to produce one or more succinimides by heating the
mixture, with or without diluent, at a temperature of from about
110.degree. C. to about 200.degree. C., preferably about
150.degree. C. to about 170.degree. C., for 1 to 20 hours. Heating
for about 3 to about 6 hours is preferred. Reactants may be mixed
and then heated or heating may occur while the reactants are being
mixed. During the heating period, water of the reaction may be
removed by any means known in the art. Any PIBSA may be used. This
includes thermal PIBSA made from conventional PIB or high
reactivity PIB, chlorination PIBSA, a mixture of thermal and
chlorination PIBSA, sulfonic acid catalyzed PIBSA, PolyPIBSA, or
Terpolymer PIBSA. A mixture of PIBSA and a copolymer may also be
used. An amine/PIBSA charge mole ratio (CMR) of about 0.4 to 0.6
may be used. A preferred CMR may be about 0.4 to about 0.5. After
heating, the reaction mixture may be cooled to about 110.degree. C.
to about 150.degree. C., preferably about 130.degree. C. to about
135.degree. C. Terephthalic acid may then be added. About 2% to
about 5% terephthalic acid, preferably about 2.5% to about 3.5% by
weight, based on the succinimide weight may be used. This mixture
may then be heated for about 1 to about 10 hours, preferably about
2 to about 4 hours. The mixture may then be filtered. Another
embodiment of this invention may comprise one or more corrosion
inhibitors synthesized by reacting 1000 molecular weight
polyisobutenesuccinic anhydride (PIBSA) with tetraethylenepentamine
(TEPA) using an amine/PIBSA charge mole ratio (CMR) of 0.71. This
produces a reaction product, which may then be reacted with
terephthalic acid to form a dispersed aromatic dicarboxylic acid
corrosion inhibitor.
[0161] The preparation of said corrosion inhibitors is further
described, for example, in U.S. patent application Ser. No.
10/367,432, filed Feb. 14, 2003, which is incorporated herein in
its entirety.
[0162] Wear Inhibitors
[0163] Traditional wear inhibitors may be used in this invention.
As their name implies, these agents reduce wear of moving metallic
parts. Examples of such agents include, but are not limited to
phosphates, phosphites, carbamates, esters, sulfur containing
compounds, and molybdenum complexes. The LEDL of this invention may
comprise one or more wear inhibitors such metal dithiophospates and
metal dithiocarbamates or mixtures thereof. A preferred wear
inhibitor for use in this invention comprises zinc
dithiophosphate.
[0164] Other Additive Components
[0165] The following additive components are examples of some
components that can be favorably employed in the present invention.
These examples of additives are provided to illustrate the present
invention, but they are not intended to limit it:
[0166] (1) Ashiess dispersants: alkenyl succinimides, alkenyl
succinimides modified with other organic compounds, and alkenyl
succinimides modified with boric acid, alkenyl succinic ester;
EC-treated dispersants.
[0167] (2) Oxidation inhibitors:
[0168] (a) Phenol type oxidation inhibitors: 4,4'-methylene bis
(2,6-di-tert-butylphenol), 4,4'-bis(2,6-di-tert-butylphenol),
4,4'-bis(2-methyl-6-tert-butylphenol), 2,2'-methylene
bis(4-methyl-6-tert-butyl-phenol),
4,4'-butylidenebis(3-methyl-6-tert-but- ylphenol),
4,4'-isopropyl-idenebis(2,6-di-tert-butylphenol),
2,2'-methylene-bis(4-methyl-6-nonylphenol),
2,2'-isobutylidene-bis(4,6dim- ethyl-phenol), 2,2'-methylenebis
(4-methyl-6-cyclohexylphenol), 2,6-di-tert-butyl4-methyl-phenol,
2,6-di-tert-butyl4-ethylphenol, 2,4-dimethyl-6-tert-butyl-phenol,
2,6-di-tert-4-(N,N'-dimethyl-aminomethy- lphenol),
4,4'-thiobis(2-methyl-6-tert-butylphenol),
2,2'-thiobis(4-methyl-6-tert-butylphenol),
bis(3-methyl4-hydroxy-5-tert-b- utylbenzylysulfide, and bis
(3,5-di-tert-butyl4-hydroxybenzyl).
[0169] (b) Diphenylamine type oxidation inhibitor: alkylated
diphenylamine, phenyl-.alpha.-naphthylamine, and
alkylated.alpha.-naphthy- lamine.
[0170] (c) Other types: metal dithiocarbamate (e.g., zinc
dithiocarbamate), molybdenum oxysulfide succinimide complexes, and
methylenebis (dibutyl-dithiocarbamate).
[0171] (3) Rust inhibitors (Anti-rust agents)
[0172] (a) Nonionic polyoxyethylene surface active agents:
polyoxyethylene lauryl ether, polyoxyethylene higher alcohol ether,
polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl
ether, polyoxyethylene octyl stearyl ether, polyoxyethylene oleyl
ether, polyoxyethylene sorbitol monostearate, polyoxyethylene
sorbitol mono-oleate, and polyethylene glycol monooleate.
[0173] (b) Other compounds: stearic acid and other fatty acids,
dicarboxilic acids, metal soaps, fatty acid amine salts, metal
salts of heavy sulfonic acid, partial carboxylic acid ester of
polyhydric alcohol, and phosphoric ester.
[0174] (4) Demulsifiers: addition product of alkylphenol and
ethyleneoxide, poloxyethylene alkyl ether, and polyoxyethylene
sorbitan ester.
[0175] (5) Extreme pressure agents (EP agents): zinc
dialkyldithiophosphate (aryl zinc, primary alkyl, and secondary
alkyl type), sulfurized oils, diphenyl sulfide, methyl
trichlorostearate, chlorinated naphthalene,
fluoroalkylpolysiloxane, and lead naphthenate.
[0176] (6) Friction modifiers: fatty alcohol, fatty acid, amine,
borated ester, and other esters.
[0177] (7) Multifunctional additives: sulfurized oxymolybdenum
dithiocarbamate, sulfurized oxymolybdenum organo phosphoro
dithioate, oxymolybdenum monoglyceride, oxymolybdenum diethylate
amide, amine-molybdenum complex compound, and sulfur-containing
molybdenym complex compound.
[0178] (8) Viscosity index improvers: polymethacrylate type
polymers, ethylene-propylene copolymers, styrene-isoprene
copolymers, hydrated styrene-isoprene copolymers, polyisobutylene,
and dispersant type viscosity index improvers.
[0179] (9) Pour point depressants: polymethyl methacrylate.
[0180] (10) Foam Inhibitors: alkyl methacrylate polymers and
dimethyl silicone polymers.
[0181] (11) Metal detergents: sulfurized or unsulfurized alkyl or
alkenyl phenates, alkyl or alkenyl aromatic sulfonates, calcium
sulfonates, sulfurized or unsulfurized metal salts of multi-hydroxy
alkyl or alkenyl aromatic compounds, alkyl or alkenyl hydroxy
aromatic sulfonates, sulfurized or unsulfurized alkyl or alkenyl
naphthenates, metal salts of alkanoic acids, metal salts of an
alkyl or alkenyl multiacid, and chemical and physical mixtures
thereof.
[0182] Low Emission Diesel Lubricating Oil Composition
[0183] The LEDL of the present invention is useful for its improved
detergency over other engine lubricating oil compositions. Such a
lubricating oil composition comprises a major part of a base oil of
lubricating viscosity and from about 0 wt. % to about 1.2 wt. %
ash; from about 0.1 wt. % to about 0.5 wt. % sulfur; and from about
0.02 wt. % to about 0.1 wt. % phosphorus. Said LEDLs provide
improved detergency while at the same time providing compatibility
with exhaust gas after-treatment systems.
[0184] In one embodiment, the LEDL would contain:
[0185] (a) a major part of a base oil of lubricating viscosity;
[0186] (b) 0% to 1.2 wt. % ash;
[0187] (c) 0.05% to 0.5 wt. % sulfur;
[0188] (d) 0.02% to 0.1 wt. % phosphorus;
[0189] (e) 1% to 12% of at least one dispersant;
[0190] (f) 0.5% to 1.1% of at least one zinc dithiophosphate;
[0191] (g) 0% to 2.5% of at least one oxidation inhibitor;
[0192] (h) 0% to 1% of at least one foam inhibitor;
[0193] (i) 0% to 10% of at least one viscosity index improver;
and
[0194] (j) 0% to 0.5% corrosion inhibitor.
[0195] In another embodiment, the LEDL of the present invention
would contain the above components and from about 1.8% to about 5.5
wt % of the unsulfurized, carboxylate-containing hydroxy-aromatic
surfactant-based detergent-dispersant additive of the present
invention. It has been found that LEDLs containing said additive
provide superior corrosion protection to LEDLs containing
commercially available salicylates at constant ash, sulfur and
phosphorus levels.
[0196] It has been found that LEDLs of the instant invention may be
prepared such that they contain very low sulfur. Very low sulfur is
defined to mean about 0.05 wt. % to about 0.3 wt. % sulfur.
Surprisingly, very low sulfur LEDLs prepared according to the
instant invention provide superior corrosion protection when used
in an internal combustion engine.
[0197] In a further embodiment, the LEDL is produced by blending a
mixture of the above components. The LEDL produced by that method
might have a slightly different composition than the initial
mixture, because the components may interact. The components can be
blended in any order and can be blended as combinations of
components.
EXAMPLES
[0198] The invention will be further illustrated by following
examples, which set forth particularly advantageous method
embodiments. While the Examples are provided to illustrate the
present invention, they are not intended to limit it.
Example 1
[0199] Preparation of the Unsulfurized, Carboxylate-Containing
Hydroxy-Aromatic Surfactant-Based Detergent-Dispersant Additive
[0200] An intermediate product was prepared according to the
procedure given in U.S. Pat. No. 6,162,770, Example 1. Said
procedure is reproduced here:
[0201] A. Neutralization
[0202] A charge of 875 g of branched dodecylphenol (DDP) having a
molecular mass of 270, (i.e. 3.24 moles) and 875 g of linear
alkylphenol having a molecular mass of about 390 (i.e. 2.24 moles)
was placed in a four-necked 4 liter glass reactor above which was a
heat-insulated Vigreux fractionating column. The isomeric molar
repartition of para versus ortho alkylphenol was:
[0203] DDP: 89% para and 5.5% ortho
[0204] Linear alkylphenol: 39% para and 53% ortho.
[0205] The agitator was started up and the reaction mixture was
heated to 65.degree. C., at which temperature 158 grams of slaked
lime Ca(OH).sub.2 (i.e. 2.135 moles) and 19 g of a mixture (50/50
by weight) of formic acid and acetic acid were added.
[0206] The reaction medium underwent further heating to 120.degree.
C. at which temperature the reactor was placed under a nitrogen
atmosphere, then heated up to 165.degree. C. and then the nitrogen
introduction was stopped. Distillation of water commenced at this
temperature.
[0207] The temperature was increased to 240.degree. C. and the
pressure was reduced gradually below atmospheric until an absolute
pressure of 5,000 Pa (50 mbars) was obtained.
[0208] The reaction mixture was kept for five hours under the
preceding conditions. The reaction mixture was allowed to cool to
180.degree. C., then the vacuum was broken under a nitrogen
atmosphere and a sample was taken for analysis.
[0209] The total quantity of distillate obtained was about 120
cm.sup.3; demixing took place in the lower phase (66 cm.sup.3 being
water).
[0210] B. Carboxylation
[0211] The product obtained in Step (A) was transferred to a
3.6-liter autoclave and heated to 180.degree. C.
[0212] At this temperature, scavenging of the reactor with carbon
dioxide (CO.sub.2) was commenced and continued for ten minutes. The
amount of CO.sub.2 used in this step was in the order of 20
grams.
[0213] After the temperature had been raised to 200.degree. C., the
autoclave was closed, leaving a very small leak, and the
introduction of CO.sub.2 was continued so as to maintain a pressure
of 3.5.times.10.sup.5 Pa (3.5 bars) for 5 hours at 200.degree. C.
The amount of CO.sub.2 introduced was in the order of 50 grams.
After the autoclave had been cooled to 165.degree. C., the pressure
was restored to atmospheric and the reactor was then purged with
nitrogen.
[0214] A total quantity of 1,912 grams of product was recovered
prior to filtration. The product was then filtered.
[0215] The above procedure was scaled up to a 6000 gallon reactor
and used to prepare the intermediate product. The intermediate
product was then subjected to the additional step of distillation
outlined below.
[0216] Analytical results for the intermediate product from the
6000 gallon batch were as follows:
1 TBN 116 mg KOH/gm Calcium 4.1 wt % Salicylic Acid Index (SAI) 40
mg KOH/gm
[0217] SAI is a measure of the quantity of alkylsalicylate formed
in the detergent-dispersant. It was determined by acidification of
the product by a strong acid (hydrochloric acid) in the presence of
diethyl ether, followed by a potentiometric titration on the
organic fraction (tetra n-butyl ammonium hydroxide was used as a
titration agent). Results are expressed in equivalent mg KOH per
gram of product (Base Number unit).
[0218] C. Distillation:
[0219] The intermediate product was fed at a rate of 70 kg/hr to a
wiped film evaporator (WFE) which had a surface area of 0.39
m.sup.2. The WFE had an internal condenser and entrainment
separator along with a hot oil jacket. The hot oil temperature in
the jacket was about 250.degree. C. The pressure within the WFE was
1.3 mbar. The feed temperature to the WFE was 135.degree. C. Final
product temperature exiting the WFE was 222.degree. C. The product
was cooled to less than 100.degree. C. before diluting with 100N
base oil. Approximately 47.5% (by weight) of the feed to the WFE
was collected as distillate. The amount of distillate collected may
vary from 10% up to about 55% by weight of the feed to the WFE.
Depending upon the level of distillation, enough organic diluent is
then added to the distilled product to give a manageable viscosity.
As the weight percentage of feed collected as distillate increases,
the amount of diluent needed to be added to the distilled product
in order to give a manageable viscosity increases.
[0220] Analytical results for the distilled product were as
follows:
2 TBN 174 mg KOH/gm Ca 6.09 wt % Salicylic Acid Index (SAI) 58
Viscosity at 100.degree. C. 705 cSt Oil Content (by mass balance)
21.5 wt %
[0221] It is well known in the art that salicylate structures are
thermally unstable. As the distilled material had a comparable
Salicylic Acid Index to calcium ratio as the feedstock, no
decomposition of the salicylate structure occurred even though the
feed was exposed to relatively high temperatures. No decomposition
occurred as the residence time in the WFE is relatively short. The
distillate appearance was clear and slightly yellow which is
comparable to the appearance of the starting hydrocarbyl phenols
introduced in the neutralization step. The TBN content of the
distillate was essentially zero indicating than none of the
feedstock to the distillation step carried over into the
distillate. The distillate was analyzed by gas chromatography and
found to contain approximately 61% branched hydrocarbyl phenol, 39%
linear hydrocarbyl phenol, and 6% 100N base oil.
Example 2
[0222] The pre-distillation product prepared according to Example 1
was distilled under various conditions in the WFE described above.
Typical results for other distillation conditions are shown in
Table 1.
3 TABLE 1 1 2 WFE Conditions: Feed Rate (kg/hr) 122 86 Pressure
(mbar) 1.44 1.5 Hot Oil Temp (.degree. C.) 235 254 Product
Temperature 205 222 Exiting Evaporator (.degree. C.) Amount of
Distillate (wt %).sup.1 30 43 Oil in Final Product (wt %) 0 14.5
Product Analytical Results TBN (mg KOH/gm) 166 174 Ca (wt %) 5.92
6.2 SAI (mg KOH/gm) 57 59 Viscosity @ 100.degree. C. 226 575 (cSt)
Compostion of Distillate Branched Alkylphenol 76 64 (wt %) Linear
Alkylphenol 15 27 (wt %) 100 N Base Oil (wt %) 9 9 .sup.1Based on
WFE Feed Rate
Example 3
[0223] Example 1 was repeated except for the following changes:
[0224] a) The WFE had a surface area of 0.78 m.sup.2
[0225] b) The feed rate to the WFE was about 135 kg/hr
[0226] c) The final distilled product was diluted with about 36 wt
% 100N oil to produce a product with a manageable viscosity.
Similar to Example 1, about 46% (based on weight) of the feed to
the evaporator was collected as distillate.
[0227] Analytical results for this product are as follows:
4 TBN 138 mg KOH/gm Calcium 4.96 wt % SAI 47 mg KOH/gm
[0228] Dialysis was performed on about 15 gm of product from
Example 3 using a Soxhlet extraction apparatus (pentane solvent)
and a Latex membrane condom for about 24 hours to afford a
dialysate fraction (the material that passes through the membrane)
and a residue fraction (the material left in the latex membrane
bag).
[0229] The dialysate fraction from the dialysis procedure was
separated into two fractions using silica gel chromatography
(0.2-0.25 gm on two Silica Gel Cartridges--Waters Part No. 051900)
first using 12 ml of hexane to yield Fraction 1 followed by
reversing the Cartridges and flushing with 12 ml of 80:20 Ethyl
Acetate: Ethanol to afford Fraction 2. Fraction 1 was comprised of
diluent oil and Fraction 2 was comprised of free alkylphenols.
[0230] The Fraction 2 obtained from the chromatographic separation
procedure was analyzed using supercritical chromatography (SFC) to
determine the amount of branched alkylphenol and linear alkylphenol
present. Quantification was performed using a calibration curve of
known mixtures of branched and linear alkylphenol.
[0231] % SA was determined on the dialysis residue fraction by
acidification of the product by a strong acid (hydrochloric acid)
in the presence of diethyl ether, followed by a potentiometric
titration on the organic fraction (tetra n-butyl ammonium hydroxide
was used as a titration agent). This method separates and
quantifies the alkyl salicylic acid and the remaining alkylphenol
(non-carboxylated alkylphenate). Results were expressed in
equivalent mg KOH per gram of product (Base Number unit). % SA was
then determined by using the following equation:
% SA=100*(Alkylsalicylic acid/(Alkylphenol+Alkylsalicylic
acid))
[0232] % Ca in the residue was determined by classical X Ray
spectrometry.
5 Dialysis results are as follows: Dialysate 51.1 wt % of starting
sample weight Residue 48.9 wt % of starting sample weight Dialysate
Composition: Dodecylphenol 1.0 wt % Linear Alkylphenol 26.7 wt %
100 N Base Oil 72.3 wt % Residue Composition: Calcium 9.3 wt % TBN
259 mg KOH/gm SAI 78 mg KOH/gm % SA 50
[0233] The following composition of the product produced in Example
3 was calculated from the composition of the dialysate and residue
fractions:
6 Total Alkylphenol Content 14.1 wt % Oil 36.9 wt % Single Aromatic
Ring Alkylsalicylate 24.5 wt % Calcium Alkylphenate 24.5 wt %
[0234] Procedures for Performance Tests
[0235] The following Section describes Performance Test Methods
referred to in these examples.
[0236] Corrosion Control (ASTM D6594-01)
[0237] This is a standard test method for evaluation of
corrosiveness of diesel engine oil at 135.degree. C. This test
method is used to test diesel engine lubricants to determine their
tendency to corrode various metals, specifically alloys of lead and
copper commonly used in cam followers and bearings. Four metal
specimens of copper, lead, tin, and phosphor bronze are immersed in
a measured amount of engine oil. The oil, at an elevated
temperature, is blown with air for a period of time. When the test
is completed, the copper specimen and the stressed oil are examined
to detect corrosion and corrosion products, respectively.
Examples Showing Performance Advantages
[0238] The following Examples illustrate performance advantages
demonstrated by the LEDLs of the present invention.
Example 4
[0239] Automotive Performance
[0240] The lubrication oil formulations used in the present example
were designed for Low Emission Diesel Lubricants (LEDL) intended
for use in Low Emission Diesel Engines and had the following
compositions:
7 Baseline Formulation A A B B C C Sulfated Ash, % 0.95 0.95 1.0
1.0 1.0 1.0 Sulfur, % 0.10 0.10 0.12 0.12 0.10 0.10 Phosphorus, %
0.05 0.05 0.05 0.05 0.05 0.05 Borated Dispersant Y Y Y Y Y Y
Non-Borated Dispersant Y Y Y Y Y Y LOB Ca-Sulfonate N N Y Y N N LOB
Salicylate N N N N Y Y Commercially Available 4.5 N 4.5 N 4.5 N
Salicylate, wt % Unsulfurized Carboxylate- N 5.0 N 5.0 N 5.0
Containing additive prepared according to Example 1, wt % Secondary
ZnDTP Y Y Y Y Y Y Diphenylamine Anti-Oxidant Y Y Y Y Y Y Molybdenum
Anti-Oxidant Y Y Y Y Y Y Foam Inhibitor Y Y Y Y Y Y Olefin
Co-polymer Viscosity Y Y Y Y Y Y Index Improver Base Oil 1 Y Y Y Y
Y Y Base Oil 2 Y Y Y Y Y Y HTCBT Pb, ppm 118 60 140 74 230 108
[0241] Three pairs of LEDL formulations, each pair with the same
levels of ash, sulfur and phosphorus, were prepared. For each pair
of formulations, an LEDL containing the unsulfurized,
carboxylate-containing hydroxy-aromatic surfactant-based
detergent-dispersant additive employed in the present invention was
compared to an LEDL containing a commercially available salicylate
for corrosion performance. In each case, the LEDL of the present
invention containing the carboxylate-containing additive displayed
superior corrosion control performance. Surprisingly, even at very
low sulfur levels, acceptable performance was obtained.
Example 5
[0242] Automotive Performance
[0243] The lubrication oil formulations used in the present example
were designed for Low Emission Diesel Lubricants (LEDL) intended
for use in Low Emission Diesel Engines and had the following
compositions:
8 Description A B C D E Sulfated Ash, % 0.54 0.86 0.47 0.68 0.90
Sulfur, % 0.18 0.18 0.12 0.12 0.12 Phosphorus, % 0.08 0.08 0.05
0.05 0.05 Borated Dispersant Y Y Y Y Y Non-Borated Dispersant Y Y Y
Y Y Co-Detergent Y Y Y Y Y Unsulfurized Carboxylate-Containing 2.0
3.9 1.9 3.2 4.4 additive prepared according to Example 1, wt %
Secondary ZnDTP, wt % 1.04 1.04 0.66 0.66 0.66 Diphenylamine
Anti-Oxidant Y Y Y Y Y Phenolic Anti-Oxidant Y Y Y Y Y Molybdenum
Anti-Oxidant Y Y Y Y Y Corrosion Inhibitor Y Y Y Y Y Foam Inhibitor
Y Y Y Y Y OCP VII Y Y Y Y Y Base Oil 1 Y Y Y Y Y Base Oil 2 Y Y Y Y
Y HTCBT Pb, ppm 73 48 62 79 75
[0244] For each LEDL, covering a range of sulfur, phosphorus and
ash levels, the LEDL displayed superior corrosion control
performance. Said performance is not degraded by decreasing the wt.
% ZnDTP. Even at very low sulfur levels, the LEDL of the present
invention displayed superior corrosion control performance.
Example 6
[0245] Preperation of Very Low Sulfur LEDL
[0246] 3.2 mmol of ZnDTP is combined with the following
components:
[0247] from 1 wt. % to 4 wt. % borated dispersant;
[0248] from 3 wt. % to 8 wt. % non-borated dispersant;
[0249] from 4 to 8 mmol LOB Ca-Sulfonate;
[0250] from 0 wt. % to 0.5 wt. % corrosion inhibitor;
[0251] from 0.1 wt. % to 0.5 wt. % molybdenum anti-oxidant;
[0252] from 0 wt. % to 1 wt. % phenolic anti-oxidant;
[0253] from 0.1 wt. % to 1 wt. % aminic anti-oxidant;
[0254] from 0 wt. % to 6 wt. % olefin-copolymer viscosity index
improver;
[0255] from 0 to 25 ppm foam inhibitor; and
[0256] from 1.8 wt. % to 5.5 wt. % unsulfurized
carboxylate-containing hydroxy-aromatic su rfactant-based
detergent-dispersant, to produce a LEDL containing 0.02 wt. %
phosphorus and 0.06 wt. % sulfur.
[0257] While the present invention has been described with
reference to specific embodiments, this application is intended to
cover those various changes and substitutions that may be made by
those skilled in the art without departing from the spirit and
scope of the appended claims.
* * * * *