U.S. patent application number 12/477795 was filed with the patent office on 2009-12-03 for method of lubricating food processing equipment and related food grade, high temperature lubricants and compositions.
This patent application is currently assigned to Inolex Investment Corporation. Invention is credited to Rocco Burgo, Tyler Housel.
Application Number | 20090298731 12/477795 |
Document ID | / |
Family ID | 41380571 |
Filed Date | 2009-12-03 |
United States Patent
Application |
20090298731 |
Kind Code |
A1 |
Housel; Tyler ; et
al. |
December 3, 2009 |
Method of Lubricating Food Processing Equipment and Related Food
Grade, High Temperature Lubricants and Compositions
Abstract
Methods of lubricating food processing equipment that include
applying a food grade, high temperature lubricant composition to
the food processing equipment are described. The composition
includes a polyol polyester base oil that is a reaction product of
at least one neopentyl polyhydric alcohol and at least one
monocarboxylic acid. Also described are methods of preparing a food
grade, high temperature composition comprising reacting at least
one neopentyl polyhydric alcohol and at least one monocarboxylic
acid. The composition may be a lubricant composition. Additionally,
the invention provides a food grade, high temperature lubricant
composition comprising a polyol polyester base oil that is a
reaction product of at least one neopentyl polyhydric alcohol and
at least one monocarboxylic acid.
Inventors: |
Housel; Tyler; (Lansdale,
PA) ; Burgo; Rocco; (Mullica Hill, NJ) |
Correspondence
Address: |
FLASTER/GREENBERG P.C.;Four Penn Center
1600 John F. Kennedy Boulevard, 2nd Floor
PHILADELPHIA
PA
19103
US
|
Assignee: |
Inolex Investment
Corporation
Wilmington
DE
|
Family ID: |
41380571 |
Appl. No.: |
12/477795 |
Filed: |
June 3, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61058493 |
Jun 3, 2008 |
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Current U.S.
Class: |
508/485 |
Current CPC
Class: |
C10M 2215/223 20130101;
C10M 2201/1056 20130101; C10N 2030/06 20130101; C10N 2050/10
20130101; C10M 2213/0626 20130101; C10N 2020/071 20200501; C10M
2223/047 20130101; C10N 2030/74 20200501; C10M 2207/025 20130101;
C10M 2203/1006 20130101; C10M 2207/044 20130101; C10M 2219/084
20130101; C10M 2223/043 20130101; C10M 105/38 20130101; C10M
2205/0285 20130101; C10N 2030/10 20130101; C10M 2207/024 20130101;
C10M 2207/2835 20130101; C10N 2030/08 20130101; C10M 2207/026
20130101; C10N 2030/62 20200501; C10M 2201/056 20130101; C10M
2219/0445 20130101; C10M 2215/064 20130101; C10M 2215/065 20130101;
C10M 2207/289 20130101; C10N 2010/04 20130101; C10M 169/044
20130101; C10M 169/04 20130101; C10N 2020/069 20200501; C10N
2030/02 20130101; C10M 2207/401 20130101 |
Class at
Publication: |
508/485 |
International
Class: |
C10M 105/38 20060101
C10M105/38 |
Claims
1. A method of lubricating food processing equipment comprising
applying a food grade, high temperature lubricant composition to
the food processing equipment, wherein the composition comprises a
polyol polyester base oil that is a reaction product of at least
one neopentyl polyhydric alcohol and at least one monocarboxylic
acid and the composition is capable of achieving an H1
classification.
2. The method of claim 1, wherein the at least one neopentyl
polyhydric alcohol comprises dipentaerythritol.
3. The method of claim 1, wherein the at least one monocarboxylic
acid contains about 5 to about 12 carbon atoms.
4. The method of claim 1, wherein the polyol polyester base oil is
a reaction product of at least one neopentyl polyhydric alcohol and
at least two monocarboxylic acids that each has a different
structure from the other.
5. The method of claim 4, wherein the first of the at least two
monocarboxylic acids is straight chained and the second of the at
least two monocarboxylic acids is branched.
6. The method of claim 6, wherein the at least one monocarboxylic
acid is chosen from a monocarboxylic acid having about 5 to about
10 carbon atoms and a monocarboxylic acid having about 5 or about 7
carbon atoms.
7. The method of claim 6, wherein the at least one monocarboxylic
acid comprises 3,5,5 trimethyl hexanoic acid.
8. The method of claim 1, wherein the at least one neopentyl
polyhydric alcohol comprises dipentaerythritol, and the at least
one monocarboxylic acid is chosen from pentanoic acid, heptanoic
acid, 3,5,5-trimethyl hexanoic acid and combinations thereof.
9. The method of claim 1, wherein the composition further comprises
one or more of an additive chosen from an antioxidant, an
antioxidant system, a metal passivating agent, a rheology modifier,
a lubricating property modifier and combinations thereof.
10. The method of claim 9, wherein the antioxidant system is chosen
from a system having at least three antioxidants and a system
having at least five antioxidants.
11. The method of claim 9, wherein the antioxidant or the
antioxidant system is present in an amount of about 1% to about 5%
by weight of the total composition.
12. The method of claim 9, wherein the antioxidant system comprises
at least three antioxidants chosen from (a) benzenepropanoic acid,
3,5-bis(1,1-dimethylethyl)-4-hydroxy-,2,2-bis[[3-[3,5-bis(1,1-dimethyleth-
yl)-4-hydroxyphenyl]-1-oxopropoxy]methyl]-1,3-propanediyl ester
(CAS number [6683-19-8]); (b) alkylated phenyl alpha naphthylamine
or N-phenyl-ar-(1,1,3,3,-tetramethylbutyl)-1-naphthalenamine (CAS
number [68259-36-9]); (c) benzenepropanoic acid,
3,5-bis(1,1-dimethyl)-4-hydroxy-,1,6-hexanediyl ester (CAS number
[35074-77-2]); (d) benzenepropanoic acid,
3,5-bis(1,1-dimethylethyl)-4-hydroxy-,thiodi-2,1-ethanediyl ester
(CAS number [41484-35-9]); (e) a mixture containing
1-hydroxy-4-methyl-2,6-di-tert-butylbenzene; (f)
N-phenyl-1-naphthyl amine (CAS number [90-30-2]); (g) a liquid
diphenylamine-based antioxidant) and (h) mixed octylated and
butylated diphenylamine or benzeneamine,-N-phenyl-, reaction
product with 2,4,4-trimethylpentane and 2-methylpropene (CAS number
[184378-08-3]); and (i) liquid dl-alpha tocopherol;
2H-1-Benzopyran-6-ol,
3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-(CAS
number [10191-41-0]).
13. The method of claim 12, wherein the antioxidant system
comprises at least four or at least five antioxidants.
14. The method of claim 12, wherein each of antioxidant (a) to (h),
if chosen for use in the system, is present independently in an
amount of about 0.1% to about 0.5% by weight of the total
composition.
15. The method of claim 12, comprising an additive in an amount of
about 1% or less by weight of the total composition, wherein the
additive is chosen from a lubricating property modifier and a metal
passivating agent.
16. The method of claim 9, wherein the rheology modifier is present
in an amount of about 0.2% to about 60% by weight of the total
composition.
17. The method of claim 1, wherein the composition has a kinematic
viscosity at 40.degree. C. of about 60 to about 400 centistokes and
a flash point of at least about 270.degree. C.
18. The method of claim 1, wherein application of the composition
to the equipment is accomplished by a process chosen from spraying
and dipping.
19. The method of claim 1, wherein application of the composition
to the equipment is accomplished by a process chosen from brushing,
sponging, wiping, flushing, and irrigating.
20. A method of preparing a food grade high temperature lubricant
comprising reacting at least one neopentyl polyhydric alcohol and
at least one monocarboxylic acid, and the lubricant composition is
capable of achieving an H1 classification.
21. The method of claim 20, wherein the at least one neopentyl
polyhydric alcohol comprises dipentaerythritol.
22. The method of claim 20, wherein the at least one monocarboxylic
acid contains about 5 to about 12 carbon atoms.
23. The method of claim 20, wherein the polyol polyester base oil
is a reaction product of at least one neopentyl polyhydric alcohol
and at least two monocarboxylic acids that each has a different
structure from the other.
24. The method of claim 23, wherein the first of the at least two
monocarboxylic acids is straight chained and the second of the at
least two monocarboxylic acids is branched.
25. The method of claim 23, wherein the at least one monocarboxylic
acid is chosen from a monocarboxylic acid having about 5 to about
10 carbon atoms and a monocarboxylic acid having about 5 or about 7
carbon atoms.
26. The method of claim 20, wherein the at least one monocarboxylic
acid comprises 3,5,5 trimethyl hexanoic acid.
27. The method of claim 20, wherein the at least one neopentyl
polyhydric alcohol comprises dipentaerythritol, and the at least
one monocarboxylic acid is chosen from pentanoic acid, heptanoic
acid, 3,5,5-trimethyl hexanoic acid and combinations thereof.
28. The method of claim 20, wherein the composition further
comprises one or more of an additive chosen from an antioxidant, an
antioxidant system, a rheology modifier, a metal passivating agent,
a lubricating property modifier, and combinations thereof.
29. The method of claim 28, wherein the antioxidant system
comprises at least three different antioxidants.
30. The method of claim 29, wherein the antioxidant system
comprises at least three antioxidants chosen from (a)
benzenepropanoic acid,
3,5-bis(1,1-dimethylethyl)-4-hydroxy-,2,2-bis[[3-[3,5-bis(1,1-dimethyleth-
yl)-4-hydroxyphenyl]-1-oxopropoxy]methyl]-1,3-propanediyl ester
(CAS number [6683-19-8]); (b) alkylated phenyl alpha naphthylamine
or N-phenyl-ar-(1,1,3,3,-tetramethylbutyl)-1-naphthalenamine (CAS
number [68259-36-9]); (c) benzenepropanoic acid,
3,5-bis(1,1-dimethyl)-4-hydroxy-,1,6-hexanediyl ester (CAS number
[35074-77-2]); (d) benzenepropanoic acid,
3,5-bis(1,1-dimethylethyl)-4-hydroxy-,thiodi-2,1-ethanediyl ester
(CAS number [41484-35-9]); (e) a mixture containing
1-hydroxy-4-methyl-2,6-di-tert-butylbenzene; (f)
N-phenyl-1-naphthyl amine (CAS number [90-30-2]); (g) a liquid
diphenylamine-based antioxidant) and (h) mixed octylated and
butylated diphenylamine or benzeneamine,-N-phenyl-, reaction
product with 2,4,4-trimethylpentane and 2-methylpropene (CAS number
[184378-08-3]); and (i) liquid dl-alpha tocopherol;
2H-1-Benzopyran-6-ol,
3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-(CAS
number [10191-41-0]).
31. The method of claim 30, wherein the antioxidant system
comprises at least four or at least five antioxidants.
32. The method of claim 30, wherein each of antioxidant (a) to (h),
if chosen for use in the system, is present independently in an
amount of about 0.1%to about 0.5% by weight of the total
composition.
33. The method of claim 28, wherein the antioxidant or the
antioxidant system is present in an amount of about 1% to about 5%
by weight of the total composition.
34. The method of claim 28, comprising an additive in an amount of
about 1% or less by weight of the total composition, wherein the
additive is chosen from a lubricating property modifier and a metal
passivating agent.
35. The method of claim 28, wherein the rheology modifier is
present in an amount of about 0.2% to about 60% by weight of the
total composition.
36. The method of claim 20, wherein the composition has a kinematic
viscosity at 40.degree. C. of about 60 to about 400 centistokes and
a flash point of at least about 270.degree. C.
37. A food grade, high temperature lubricant composition comprising
a polyol polyester base oil that is a reaction product of at least
one neopentyl polyhydric alcohol and at least one monocarboxylic
acid.
38. The composition of claim 37, further comprising an antioxidant
system comprising at least three antioxidants chosen from (a)
benzenepropanoic acid,
3,5-bis(1,1-dimethylethyl)-4-hydroxy-,2,2-bis[[3-[3,5-bis(1,1-dimet-
hylethyl)-4-hydroxyphenyl]-1-oxopropoxy]methyl]-1,3-propanediyl
ester (CAS number [6683-19-8]); (b) alkylated phenyl alpha
naphthylamine or
N-phenyl-ar-(1,1,3,3,-tetramethylbutyl)-1-naphthalenamine (CAS
number [68259-36-9]); (c) benzenepropanoic acid,
3,5-bis(1,1-dimethyl)-4-hydroxy-,1,6-hexanediyl ester (CAS number
[35074-77-2]); (d) benzenepropanoic acid,
3,5-bis(l,l-dimethylethyl)-4-hydroxy-,thiodi-2,1-ethanediyl ester
(CAS number [41484-35-9]); (e) a mixture containing
1-hydroxy-4-methyl-2,6-di-tert-butylbenzene; (f)
N-phenyl-1-naphthyl amine (CAS number [90-30-2]); (g) a liquid
diphenylamine-based antioxidant) and (h) mixed octylated and
butylated diphenylamine or benzeneamine,-N-phenyl-, reaction
product with 2,4,4-trimethylpentane and 2-methylpropene (CAS number
[184378-08-3]); and (i) liquid dl-alpha tocopherol;
2H-1-Benzopyran-6-ol,
3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-(CAS
number [10191-41-0]).
39. The method of claim 38, wherein the antioxidant system
comprises at least four or at least five antioxidants.
40. The method of claim 38, wherein each of antioxidant (a) to (h),
if chosen for use in the system, is present independently in an
amount of about 0.1% to about 0.5% by weight of the total
composition.
41. The composition of claim 37, wherein the at least one neopentyl
polyhydric alcohol comprises dipentaerythritol.
42. The composition of claim 37, wherein the at least one
monocarboxylic acid comprises 3,5,5 trimethyl hexanoic acid.
43. The composition of claim 37, wherein the at least one neopentyl
polyhydric alcohol comprises dipentaerythritol, and the at least
one monocarboxylic acid is chosen from pentanoic acid, heptanoic
acid, 3,5,5-trimethyl hexanoic acid and combinations thereof.
44. The composition of claim 37, further comprising one or more of
an additive chosen from an antioxidant, an antioxidant system, a
rheology modifier, a metal passivating agent, a lubricating
property modifier, and combinations thereof.
45. The composition of claim 37 having a kinematic viscosity at
40.degree. C. of about 60 to about 400 centistokes and a flash
point of at least about 270.degree. C.
46. A method of lubricating food processing equipment comprising
applying a food grade, high temperature lubricant composition to
the food processing equipment, wherein the composition comprises a
polyol polyester base oil that is a reaction product of at least
one neopentyl polyhydric alcohol and at least one monocarboxylic
acid.
47. The method of claim 46, wherein the at least one neopentyl
polyhydric alcohol comprises dipentaerythritol.
48. The method of claim 46, wherein the composition further
comprises one or more of an additive chosen from an antioxidant, an
antioxidant system, a metal passivating agent, a rheology modifier,
a lubricating property modifier and combinations thereof.
49. The method of claim 48, wherein the antioxidant system
comprises at least three antioxidants chosen from (a)
benzenepropanoic acid,
3,5-bis(1,1-dimethylethyl)-4-hydroxy-,2,2-bis[[3-[3,5-bis(1,1-dimethyleth-
yl)-4-hydroxyphenyl]-1-oxopropoxy]methyl]-1,3-propanediyl ester
(CAS number [6683-19-8]); (b) alkylated phenyl alpha naphthylamine
or N-phenyl-ar-(1,1,3,3,-tetramethylbutyl)-1-naphthalenamine (CAS
number [68259-36-9]); (c) benzenepropanoic acid,
3,5-bis(1,1-dimethyl)-4-hydroxy-,1,6-hexanediyl ester (CAS number
[35074-77-2]); (d) benzenepropanoic acid,
3,5-bis(1,1-dimethylethyl)-4-hydroxy-,thiodi-2,1-ethanediyl ester
(CAS number [41484-35-9]); (e) a mixture containing
1-hydroxy-4-methyl-2,6-di-tert-butylbenzene; (f)
N-phenyl-1-naphthyl amine (CAS number [90-30-2]); (g) a liquid
diphenylamine-based antioxidant) and (h) mixed octylated and
butylated diphenylamine or benzeneamine,-N-phenyl-, reaction
product with 2,4,4-trimethylpentane and 2-methylpropene (CAS number
[184378-08-3]); and (i) liquid dl-alphatocopherol;
2H-1-Benzopyran-6-ol,
3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-(CAS
number [10191-41-0]).
50. The method of claim 49, wherein the antioxidant system
comprises at least four or at least five antioxidants.
51. The method of claim 48, wherein the antioxidant or the
antioxidant system is present in an amount of about 1%to about 5%
by weight of the total composition.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority under 35 U.S.C.
.sctn.119(e) to pending U.S. Provisional Patent Application No.
61/058,493, filed Jun. 3, 2008, the contents of which are
incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] Food processing includes various heating steps such as
cooking, baking, boiling, roasting, braising, sterilizing, drying,
broiling, steaming, and frying. Industrial equipment is often used
to mix, stir, convey, carry, form, sort, press, chop, cut, fold,
flip, package, or in other ways to handle the food ingredients as
they go through the heating steps. The food ingredients can reach
temperatures of 300.degree. C. or higher for one or more hours.
Often food processing equipment is subject to the same or higher
temperatures, and will be subjected to thousands of heat cycles per
year, requiring lubricants with sustained high temperature
performance.
[0003] Lubricants are necessary for moving parts in food processing
equipment, including those subject to high temperatures. To provide
adequate lubrication throughout the processes, a liquid film of
lubricant must remain between metal parts in rubbing, sliding or
rolling contact. Therefore, the lubricant cannot evaporate or
solidify at the peak processing temperature. Lubricants that can
maintain their structure under extremes of temperature are useful
and essential in many commercial, domestic and industrial food
processing applications.
[0004] Often, however, the conventional lubricants degrade and
become ineffective. The primary mechanisms for degradation at these
high temperatures are oxidative and/or thermal breakdown, and
polymerization. Breakdown, in which scission of the lubricant
molecule occurs, leads to the formation of lower molecular weight
volatile compounds. Evaporation of these compounds can cause
changes in viscosity, oil loss, and the production of excessive
smoke. This can lead to poor lubrication, higher cost, reduced
cleanliness of the plant, poor product quality, and higher exposure
to organic compounds. Polymerization leads to formation of
insoluble gums and varnishes that can build up in the work
environment. Cleaning these deposits requires an increase in
maintenance and generates chemical waste materials for disposal.
Further, production time is lost as machinery is taken out of
service for cleaning.
[0005] Generally, current high temperature lubrication methods
consist of dry lubrication technology such as the application of
suspensions of graphite in a volatile solvent, and liquid
lubrication through the use of more thermally stable organic
lubricants. In dry lubrication, graphite typically builds up over
time, resulting in a loss of lubrication, and requiring significant
time, work and lost production to clean the deposits. Although this
method is still employed, liquid lubrication technology has become
preferred.
[0006] Industrial lubricants generally employ different base oils
depending on the severity of the application. Lower temperature
lubricants generally use base oils consisting of hydrocarbons or
vegetable- or animal-based esters, or mixtures thereof. Synthetic
esters, particularly those based on neopolyol chemistry, provide
significantly better oxidative and thermal stability. For
industrial applications, neopolyol esters are the preferred base
oil when the lubricant must perform for longer times at higher
temperatures. Unfortunately, the neopolyol synthetic esters have
not historically been approved for food processing applications as
none has been identified as a food grade lubricant.
[0007] Because lubricants are used in environments where food is
processed and packaged, toxicity and safety of the material is of
paramount concern. Most industrialized countries, including the
United States, regulate these materials to ensure the safety of
food products. In the United States for example, these substances
are regulated as "food additives" in recognition of the fact that
the substances may be incidentally incorporated into foodstuffs
during the manufacturing process.
[0008] For use as a lubricant approved for incidental contact with
food, the lubricant must only contain substances that are: (i)
generally recognized as safe (GRAS) for use in food, (ii)
specifically identified in the FDA regulations as being safe, or
(iii) approved or sanctioned by the FDA prior to use. See, 21
C.F.R. 178.3570 (2007), the contents of which are incorporated
herein by reference. If a lubricant meets these criteria, it may be
used in lubricating applications where it may incidentally contact
food.
[0009] NSF International (website nsf.org) maintains uniform
standards for products such as incidental food additives and
lubricants and its ratings are relied upon throughout the world by
processers. If the FDA criteria listed above are met for a given
substance, NSF International grants the lubricant composition a
rating of Hi, indicating that the substance is a lubricant suitable
for food contact.
[0010] Many lubricants based on mineral oils, synthetic hydrocarbon
oils or vegetable oils have an NSF International H1 ranking. These
base fluids have relatively poor performance at high temperatures,
either because of inadequate viscosity, excessive evaporation or
formation of solid, non-lubricious deposits. Therefore, a need
exists for a lubricant formulation with superior high temperature
fluidity that can be used to lubricate food processing machinery
that is routinely exposed to high temperatures and which is safe
for food contact.
BRIEF SUMMARY OF THE INVENTION
[0011] The invention provides methods of lubricating food
processing equipment that include applying a food grade, high
temperature lubricant composition to the food processing equipment.
The composition comprises a polyol polyester base oil that is a
reaction product of at least one neopentyl polyhydric alcohol and
at least one monocarboxylic acid.
[0012] Also provided are methods of preparing a food grade, high
temperature composition comprising reacting at least one neopentyl
polyhydric alcohol and at least one monocarboxylic acid. The
composition may be a lubricant composition.
[0013] Additionally, the invention provides a food grade, high
temperature lubricant composition comprising a polyol polyester
base oil that is a reaction product of at least one neopentyl
polyhydric alcohol and at least one monocarboxylic acid.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The invention provides (i) methods of lubricating food
processing equipment using a food grade, high temperature lubricant
composition, (ii) methods of preparing a food grade, high
temperature composition that may be a lubricant, and (iii) a food
grade, high temperature lubricant composition for use on food
processing equipment. Each incorporates a base oil that is a
reaction product of at least one neopentyl polyhydric alcohol and
at least one monocarboxylic acid. The process, lubricant
compositions, and methods have in common a high temperature, food
grade composition that exhibits desirable viscosity,
viscosity-temperature behavior, oxidation resistance, flash point,
anti-wear behavior, and friction reduction when used in food
processing applications and is sufficiently safe to be considered
food grade and/or achieve an HI rating under the NSF International
system.
[0015] Methods of processing foods using processing equipment that
has been lubricated with a high temperature, food grade lubricant
composition that includes a polyol polyester base oil that is a
reaction product of at least one neopentyl polyhydric alcohol and
at least one monocarboxylic acid are also disclosed.
[0016] By "food grade" it is meant a composition or lubricant that
meets the criteria set forth by the United States Food and Drug
Administration for foods additives and/or lubricants with
incidental food contact, for example, as set out in 37 C.F.R.
.sctn.178.3570 (2007), the contents of which are incorporated
herein by reference, and/or which meet the criteria to achieve an
"H1" classification from NSF International or an equivalent rating
or classification from a counterpart standards setting body.
[0017] By "high temperature" lubricant it is meant compositions
that can be exposed to temperatures of about 250.degree. C. to
300.degree. C. or greater for short duration exposure of less than
one minute to exposures of several weeks without undergoing
substantial degradation, such as oxidative breakdown, thermal
breakdown and/or polymerization.
[0018] The invention provides a food grade, high temperature
composition that can be used in and around food processing and
preparing activities and incorporated incidentally into processed
foods.
[0019] The composition includes a polyol polyester base oil ("base
oil") that is a reaction product of at least one neopentyl
polyhydric alcohol and at least one monocarboxylic acid. Properties
of these polyol polyesters such as viscosity, viscosity-temperature
behavior, oxidation resistance, evaporation loss, hydrolytic
stability, and flash point can be modified by selection of the
polyol and monocarboxylic acids used to prepare the base oil,
and/or by the manufacturing process employed. One of ordinary skill
in the art may make such modifications as desired, depending on the
end use of the product.
[0020] The neopentyl polyhydric polyol may have any suitable number
of hydroxyl groups. It may be preferred that the neopentyl
polyhydric polyol has about 3 to about 12 or about 4 to about 8
hydroxyl groups. Commercially available polyols of this type are,
for example, trimethylolpropane, trimethylolethane,
pentaerythritol, dipentaerythritol, tripentaerythritol, and
tetrapentaerythritol. Preferred polyols may be dipentaerythritol,
monopentaerythritol and trimethylolpropane or combinations thereof,
although tripentaerythritol, and tetrapentaerythritol may be
utilized.
[0021] The selected neopentyl polyhydric alcohol is reacted with at
least one monocarboxylic acid. More than one may be combined; it
may be desirable that at least two, three, four, or five
monocarboxylic acids are used. Each monocarboxylic acid may have a
structure different from the other(s), differing either in type
and/or number of chemical constituents that make up the structure
or in the arrangement of the constituents relative to one another
(e.g., branched chains versus straight chains). The monocarboxylic
acid(s) may be straight chain (linear) or branched chain (or any
combination of these). It may be preferred that the monocarboxylic
acid(s) (branched or straight chain) contain about 2 to about 20
carbon atoms, about 5 to about 12 carbon atoms, or about 5 to about
10 carbon atoms. In some circumstances, shorter chain length linear
carboxylic acids may be preferred because thermal stability may
decrease as carbon chain length increases.
[0022] Examples of linear monocarboxylic acids that may be used
include pentanoic acid, decanoic acid, hexanoic acid, heptanoic
acid, octanoic acid and nonanoic acid. Branched chain
monocarboxylic acids may also be used, either alone or in
combination with the linear or straight chained monocarboxylic
acids. For example, one may increase the amount of branched chain
monocarboxylic acids to modify (raise) the viscosity of the end
composition. Branched chain monocarboxylic acids that may be
suitable include, without limitation, 2-ethylhexanoic acid and
3,5,5-trimethylhexanoic acid (isononanoic acid).
[0023] In an embodiment, the base oil is prepared from the reaction
of at least one neopentyl polyhydric alcohol that includes
dipentaerythritol and at least one monocarboxylic acid that is
pentanoic acid, heptanoic acid, 3,5,5-trimethyl hexanoic acid
and/or any combination of these.
[0024] In addition to the base oil described above, the composition
may include one or more additional additives to modify the thermal,
chemical, aesthetic, or other properties of the composition. Any
additive may be used as long as the nature of the substance, and/or
the amount used does not substantially affect the food grade status
of the finished composition. For example, any additive that meets
the FDA criteria set out in its regulations as a food additive that
is safe for incidental contact with food may be used. Thus, all
GRAS foodstuff and food additive materials and materials rated H1
or HX-1 by NSF International may be included, as well as those
materials specifically set forth by the FDA as safe for use in food
or as food additives (direct or incidental contact) including:
aluminum stearoyl benzoyl hydroxide;
N,N-Bis(2-ethylhexyl)-ar-methyl-1H-benzotriazole-1-methanamine;
BHT; BAH,
alpha-butyl-omega-hydroxypoly(oxyethylene)poly(oxypropylene
produced by random condensation of a 1:1 mixture by weight of
ethylene oxide and propylene oxide with butanol; castor oil;
alpha-butyl-omega-hydroxypoly(oxyethylene)poly(oxypropylene);
dialkyldimethylammonium aluminum; dimethylpolysiloxane;
di(n-octyl)phosphate; disodium decanedioate; disodium EDTA;
ethoxylated resin phosphate ester mixtures consisting of:
poly(methylene-p-tert-butyl-phenoxy)poly-(oxyethylene) mixture of
dihydrogen phosphate and monohydrogen phosphate esters,
poly(methylene-p-nonylphenoxy)poly(oxyethylene) mixture of
dihydrogen phosphate and monohydrogen phosphate esters and
n-tridecyl alcohol mixture of dihydrogen phosphate and monohydrogen
phosphate esters; fatty acids derived from animal or vegetable
sources, and the hydrogenated forms of such fatty acids;
2-(8-Heptadecenyl)-4,5-dihydro-1H-imidazole-1-ethanol;
hexamethylenebis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate)1;
alpha-hydro-omega-hydroxypoly(oxyethylene)poly(oxypropylene); 1
2-hydroxystearic acid; isopropyl oleate; magnesium ricinoleate;
mineral oils; petrolatum; N-methyl-N-(1-oxo-9-octadecenyl)glycine;
N-phenylbenzenamine; phenyl-alpha-and/or phenyl-beta-naphthylamine;
phosphoric acid, mono- and dihexyl esters, compounds with
tetramethylnonylamines and alkylamines; phosphoric acid, mono- and
diisooctyl esters, reacted with tert-alkyl and (C--C) primary
amines; phosphorothioic acid, O,O,O-triphenyl ester, tert-butyl
derivatives; polyurea; polybutene; polyethylene; polyisobutylene;
sodium nitrite;
tetrakis[methylene(3,5-di-tert-butyl-4-hydroxyhydro-cinnamate)]methane;
thiodiethylenebis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate);
tri[2(or 4)-C-branched alkylphenyl]phosphorothioate; triphenyl
phosphorothionate; tris(2,4-di-tert-butylphenyl)phosphate;
thiodiethylenebis(3,5-di-tert-butyl-4-hydroxy-hydro-cinnamate; and
zinc sulfide.
[0025] Suitable optional additives may include
aesthetic/organoleptic agents, one or more antioxidants (or an
antioxidant system), rheology modifiers, metal passivating agents,
dry lubricants (such as graphite), other liquid lubricants,
lubricating property modifiers (additives for improving one or more
lubricating properties) and combinations of one or more of these
additives.
[0026] Aesthetic/organoleptic agents include any that modify the
taste, smell, color, or other aesthetic or organoleptic qualities
of the composition, including agents that disguise or reduce the
perception of undesirable qualities and agents which may serve as
indicators, e.g., an agent that turns color or hue to indicate that
the lubricant composition must be replaced. Examples include
colorants, fragrances, flavorants, and odor reducers.
[0027] Additives that act as antioxidants may be any capable of
slowing or preventing the oxidation of one or more components in
the composition. Suitable antioxidants may include, but are not
limited to, diaromatic amines, phenolics, thiophenolics, phosphites
and combinations thereof. Commercial examples include: [0028] (i)
IRGANOX.RTM. 1010 (benzenepropanoic acid,
3,5-bis(1,1-dimethylethyl)-4-hydroxy-,2,2-bis[[3-[3,5-bis(1,1-dimethyleth-
yl)-4-hydroxyphenyl]-1-oxopropoxy]methyl]-1,3-propanediyl ester,
CAS number [6683-19-8]); [0029] (ii) IRGANOX.RTM. L06 (alkylated
phenyl alpha naphthylamine or
N-phenyl-ar-(1,1,3,3,-tetramethylbutyl)-1-naphthalenamine, CAS
number [68259-36-9]); [0030] (iii) IRGANOX.RTM. L01 (di-octylated
diphenylamine), [0031] (iv) IRGANOX.RTM. L57 (a mixture of
alkylated diphenylamines); [0032] (v) IRGANOX.RTM. L150 (a mixture
of aminic and high molecular weight phenolic antioxidants); [0033]
(vi) IRGANOX.RTM. L64 (a mixture of mono- and dialkyl butyl/octyl
diphenylamines); [0034] (vii) IRGANOX.RTM. 1035 (a mixture
containing thiodiethylene bis
(3,5-di-tert-butyl-4-hydroxyhydrocinnamate); [0035] (viii)
IRGANOX.RTM. L101 (a mixture containing tetrakis
[methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl) propionato]methane);
[0036] (ix) IRGANOX.RTM. L109 (benzenepropanoic acid,
3,5-bis(1,1-dimethyl)-4-hydroxy-,1,6-hexanediyl ester, CAS number
[35074-77-2]); [0037] (x) IRGANOX.RTM. 1L115 (benzenepropanoic
acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-,thiodi-2,1-ethanediyl
ester, CAS number [41484-35-9]); [0038] (xi) IRGANOX.RTM. E201
(liquid dl-alpha tocopherol; 2H-1-Benzopyran-6-ol,
3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-, CAS
number [10191-41-0]); and [0039] (xii) IRGAFOS.RTM. 168 (a mixture
containing tris(2,4-di-tert-butylphenyl)phosphate); all from Ciba
Specialty Chemicals, Basel, Switzerland.
[0040] Also included may be the antioxidants: [0041] (i)
ADDITIN.RTM. RC7130 (N-phenyl-1-naphthyl amine, CAS number
[90-30-2]) from Rhein Chemie Corporation, Chardon, Ohio); [0042]
(ii) NA-LUBE.RTM. AO142 (a liquid diphenylamine-based antioxidant)
(from King Industries, Norwalk, Conn., United States); [0043] (iii)
VANLUBE.RTM. 961 (mixed octylated and butylated diphenylamine or
benzeneamine,-N-phenyl-, reaction product with
2,4,4-trimethylpentane and 2-methylpropene, CAS number
[184378-08-3]); and [0044] (iv) VANLUBE.RTM. PCX (a mixture
containing 1-hydroxy-4-methyl-2,6-di-tert-butylbenzene); each from
R. T. Vanderbilt, Norwalk, Conn., United States.
[0045] Each antioxidant may be included in the composition alone,
or one or more of the antioxidants can be combined into an
antioxidant system. The antioxidant(s) may be present in any
desired amount as long as the amounts and/or type of antioxidants
selected do not substantially affect the food grade property of the
composition. In some embodiments, the antioxidant system preferably
includes at least three antioxidants, at least four or at least
five antioxidants. Additionally, the antioxidant system may include
other substances that function to stabilize or otherwise maintain
the antioxidant(s). In a preferred embodiment, the antioxidant
system (e.g., sum total of all) is present at a level of about 0.5%
to about 4% by weight of the final composition or alternatively
about 1% to about 5% by weight of the composition.
[0046] In an embodiment, the composition contains an antioxidant
system containing at least three, at least four or at least five
antioxidants chosen from: (a) benzenepropanoic acid,
3,5-bis(1,1-dimethylethyl)-4-hydroxy-,2,2-bis[[3-[3,5-bis(1,1-dimethyleth-
yl)-4-hydroxyphenyl]-1-oxopropoxy]methyl]-1,3-propanediyl ester
(CAS number [6683-19-8]); (b) alkylated phenyl alpha naphthylamine
or N-phenyl-ar-(1,1,3,3,-tetramethylbutyl)-1-naphthalenamine (CAS
number [68259-36-9]); (c) benzenepropanoic acid,
3,5-bis(l,1-dimethyl)-4-hydroxy-,1,6-hexanediyl ester (CAS number
[35074-77-2]); (d) benzenepropanoic acid,
3,5-bis(1,1-dimethylethyl)-4-hydroxy-,thiodi-2, 1-ethanediyl ester
(CAS number [41484-35-9]); (e) a mixture containing
1-hydroxy-4-methyl-2,6-di-tert-butylbenzene; (f)
N-phenyl-1-naphthyl amine (CAS number [90-30-2]); (g) a liquid
diphenylamine-based antioxidant) and (h) mixed octylated and
butylated diphenylamine or benzeneamine,-N-phenyl-, reaction
product with 2,4,4-trimethylpentane and 2-methylpropene (CAS number
[184378-08-3]); and (i) liquid dl-alpha tocopherol;
2H-1-Benzopyran-6-ol,
3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-(CAS
number [10191-41-0]). In an embodiment, the antioxidants (a) to (h)
(i.e., all but the tocopherol), above, if selected to be included
in the system, may be present independently in an amount of about
0.1 weight % to about 0.5 weight %, each.
[0047] One or more additives that serve as rheology modifiers, such
as grease thickeners, food grade greases, and rheologically
modified oils may be included. Suitable rheological modifier can
include additives that are used to improve the adhesion of the
lubricant to metal parts, or impart some rheological advantage to
the lubricant. Some commercial examples are BARAGEL.RTM. 3000,
BENTONE.RTM. 34, NYKON.RTM. 77 (from Elementis Specialties
Hightstown, N.J., United States), FLUORO.RTM. FG, MICROFLON.RTM.
1433FG, MICROFLON.RTM. 1437FG, (from Shamrock Technologies, Newark,
N.J., United States), V-421, V-422, V-425, V-498, V-584 (Functional
Products), TPC.RTM. Polyisobutylene 1105 and other grades (from
Texas Petrochemicals, Houston, Tex., United States), Fumed Silica
HDK.RTM.H15, HDK.RTM.18, HDK.RTM.T40 (from Wacker Chemical
Corporation, Adrian, Mich., United States), Boron Nitride Powder
Grade AC6003 and other BN grades (from Momentive Performance
Materials, Strongville, Ohio, United States), Tackifier FG,
Calciplex FG 1605, FG 1606, FG1607, FG1608 (OMG), INSTA-GREASE.RTM.
and Tri-XL-LV.RTM. (from Chattem Chemicals, Chattanooga, Tenn.,
United States).
[0048] The selected rheology modifiers may be present in any
amount; in an embodiment it is preferred that the rheology modifier
is present in an amount of about 0.2% to about 20%, or to about 60%
by weight of the total composition or about 4% to about 11% of the
total composition.
[0049] In some embodiments, the composition may include one or more
metal passivating agents ("MPA"). Any substance that renders a
metal less active may be incorporated into the composition as an
MPA and can include corrosion inhibitors, metal deactivators, or
ion sequesterants. The MPA can include but is not limited to
triazoles, imidazolines, sarcosines, benzotriazole derivatives, and
amine phosphates. Commercial examples include IRGAMET.RTM. 39,
IRGACOR.RTM. DSS G, Amine O, SARKOSYL.RTM. O (Ciba), COBRATEC.RTM.
122 (PMC Specialties, Cincinnati, Ohio, United States), CUVAN.RTM.
303, VANLUBE.RTM. 9123 (Vanderbilt), CI-426, CI-426EP, CI-429 and
CI-498 (from Functional Products, Macedonia, Ohio, United
States)
[0050] Any amount of MPA may be included. In one embodiment, the
MPA is present in an amount of about 0.01% to about 5% by weight of
the final composition or, for example, the MPA is present in an
amount of about 0.05% to about 1% by weight of the final
composition or less than 1% of the total composition by weight.
[0051] The composition may include one or more lubricating property
modifier, i.e., any agent for improving lubricity. The modifier may
include pressure/antiwear agents and friction modifiers. At least
one such modifier may be present, for example, in an amount of
about 0.05% to about 3% by weight of the final composition. In a
preferred embodiment, the modifier is present at a level from about
0.1%to about 2% by weight of the final composition. The modifier
may include but is not limited to amines, amine phosphates,
phosphates, thiophosphates, phosphorothionates and combinations
thereof. Commercial examples include IRGALUBE.RTM. TPPT,
IRGALUBE.RTM. 232, IRGALUBE.RTM. 349, IRGALUBE.RTM. 211 (Ciba), and
ADDITIN.RTM. RC3760 Liq 396D (Rhein Chemie), FRIC-SHUN.RTM. FG 1505
and FG 1506 (from OMG Americas, Westlake, Ohio), NA-LUBE.RTM.
KR-015FG (King), LUBEBOND.RTM. (from Nowear Technologies,
Scottsdale, Ariz., United States), FLUORO(.RTM. FG (from Shamrock
Technologies, Newark, N.J., United States), SYNALOX.RTM. 40-D
series Lubricants (from Dow Chemical Company, Midland, Mich.,
United States), ACHESON.RTM. FGA 1820 and ACHESON.RTM. FGA 1810
(from Acheson Colloids, Port Huron, Mich., United States). The
modifier may be present in an amount of about 1% or less by weight
of the total composition.
[0052] Any or all of these additives may be present in the
composition as long as the additive, either individually or
combined, does not substantially affect the food grade properties
of the composition, e.g., it does not render a composition deemed
to be food grade under the FDA regulations and/or the NSF
International rating system to be a non-food grade composition. In
some embodiments, one may select and combine the additives to
optimize the high temperature performance of the finished lubricant
or composition. It may be preferred that the composition contains
mixtures of three or more additives or up to about five
additives.
[0053] The kinematic viscosity and/or the flash point of the
composition will vary, as is understood by a person of skill in the
art, depending on the specific ingredients used in the composition.
However, in an embodiment, the composition has a kinematic
viscosity at 40.degree. C. of about 60 to about 400 centistokes
and/or a flash point of at least about 270.degree. C.
[0054] Food processing equipment may be treated with the food
grade, high temperature lubricant composition of the invention.
Such equipment can include any used to cook, prepare, process, or
package any food or any element that comes in direct contact with
food, including, for example, beverages, baked goods, dairy
products, pre-prepared frozen or shelf stable foods, canned foods,
packed meats, vegetables, fruits, and pastas, processed nuts,
candies or other confections. Such equipment may include, for
example, devices and machinery used in processes of cooking,
baking, boiling, roasting, braising, sterilizing, drying, broiling,
steaming, and frying, chopping, mixing, stirring, conveying,
pressing, carrying, forming, sorting, cutting, folding, flipping,
packaging, or handling the food ingredients under heat. Examples
include ovens, conveyor belts, mixers, tanks, vats, grills, heated
surfaces, presses, molds, pans, pots, curd presses, fermentation
tanks, food handling implements and utensils, sorters, fruit
washers, dishwashers, and the like. Additionally, the equipment to
which the lubricant is applied may be any that is used to process
products placed in close contact with mammalian tissues, even
though the products are necessarily ingested. For example, such
equipment may include equipment used in the manufacture of
pharmaceuticals, vitamins, contact lenses, dermal patches, soaps,
shampoos, oral care products, medical devices, bandages, diapers,
medical implements and the like.
[0055] The food grade, high temperature lubricant may be applied to
the equipment by any means. In an embodiment the application of the
composition to the equipment may include spraying, dipping,
brushing, wiping, sponging, flushing or irrigating. The application
may be accomplished manually or may be an automated process.
EXAMPLES
[0056] In each of the examples included herein, kinematic viscosity
was tested using ASTM official method number D-445-97 (1997) (ASTM
International, West Conshohocken, Pa., United States), viscosity
index (VI) was determined using ASTM D-2270, flash point was
determined using ASTM D-92, and evaporation loss using ASTM D-972.
Frictional and antiwear properties were determined using the
four-ball method under ASTM D-4172 and the Falex method under ASTM
D-2670. Oxidation resistance was measured under ASTM D-4636 and
ASTM D-2272. The contents of each of these ASTMs are available from
ASTM International, West Conshohoken, Pa., United States and are
well known to a person of skill in the art.
[0057] Other test methods used were the "hot plate test" and the
"oven pan test". These tests allow for rapid screening of additive
systems and show distinct differences in evaporation loss and
deposit formation at high temperature.
Hot Plate Test
[0058] Data for the hot plate test results were collected as
follows: 1.+-.0.05 grams of each sample is weighed into an aluminum
dish and subsequently placed on a hot plate for 15 minutes at a
heat setting of 6.25. The sample is reweighed to determine
evaporative weight loss, and the level of deposits is visually
ranked on a scale of 1 (no deposits) through 10 (very heavy
deposits). Finally, each aluminum dish is held at an angle of 105
degrees from the horizontal, and the sample is allowed to drain for
10 minutes. The pan is weighed again to determine the residue in
the pan and (by difference) the amount of liquid that flowed out
(liquid fraction). Each sample is tested at least twice and
averages are reported. A good high temperature lubricant will have
low weight loss, deposits and residue. The major proportion of a
good lubricant will be recorded as the liquid fraction.
Oven Pan Test
[0059] Data for the oven plan test results were collected as
follows:
[0060] The oven pan test is similar to the hot plate test, but it
uses a forced air oven to heat the samples. Twelve lubricant
samples are covered and placed in the oven together. The test
typically runs for 4 to 24 hours at 260.degree. C. although other
times and temperatures can also be used. In the oven pan test, the
initial sample weight is 2.+-.0.05 grams.
Example 1
Preparation of Base Oil
[0061] A synthetic neopolyol ester base oil was prepared by
combining the materials of Table 2 in a batch reactor fitted with a
mechanical stirrer, inert gas sparge, vapor column, condenser, and
distillate receiver to form a reaction mixture.
TABLE-US-00001 TABLE 1 Reaction Material Amount (gms)
dipentaerythritol 798 pentanoic acid 410 heptanoic acid 1642 3,5,5
trimethylhexanoic acid 651
[0062] Pressure in the reactor was controlled by attaching a vacuum
pump to the system. To the reaction mixture, about 0.5 parts per
100 parts (pphp) activated charcoal, 0.005 pphp sodium
hypophosphite and 0.01 pphp of a tin based catalyst were added. The
mixture was heated to from about 180.degree. C. to about
250.degree. C. Pressure was slowly reduced until sufficient
conversion was obtained. The crude ester was further purified by
steam distillation and filtration. The result was a light yellow
liquid possessing the following properties (Table 2):
TABLE-US-00002 TABLE 2 Property Test Method Used Result Kinematic
Viscosity @ 40.degree. C., cSt ASTM D-445 71 Kinematic Viscosity @
100.degree. C., cSt ASTM D-445 10 Acid Value ASTM D-3242 0.019
Flash Point, .degree. C. ASTM D-92 289
Preparation of Base Oil
Example 2
[0063] A synthetic neopolyol ester base oil was prepared by
combining the materials of Table 3 in a batch reactor fitted with a
mechanical stirrer, inert gas sparge, vapor column, condenser, and
distillate receiver to form a reaction mixture.
TABLE-US-00003 TABLE 3 Reaction Material Amount (gms)
Dipentaerythritol 412 pentanoic acid 38 heptanoic acid 38 3,5,5
trimethylhexanoic acid 1613
[0064] Pressure in the reactor was controllable by attaching a
vacuum pump to the system. To the reaction mixture, about 0.5 parts
per 100 parts (pphp) activated charcoal, 0.005 pphp sodium
hypophosphite and 0.01 pphp of a tin based catalyst were added and
the mixture was heated to from about 180.degree. C. to about
250.degree. C. Pressure was slowly reduced until sufficient
conversion was obtained. The crude ester was further purified by
steam distillation and filtration. The result was a light yellow
liquid possessing the following properties (Table 4):
TABLE-US-00004 TABLE 4 Property Test Method Result Kinematic
Viscosity@40.degree. C., cSt ASTM D-445 338 Kinematic Viscosity @
100.degree. C., cSt ASTM D-445 23 Acid Value ASTM D-3242 0.015
Flash Point, .degree. C. ASTM D-92 307
Example 3
Stabilized Lubricant Examples
[0065] An experiment was designed and carried out to determine the
relative benefits of five different food grade antioxidants in the
base oils listed in examples above. The antioxidants included were
Vanlube 961, IRGANOX.RTM. 1010, IRGANOX.RTM. L115, IRGANOX.RTM.
E201 and Vanlube PCX. Base oils of examples 1 and 2 were blended to
achieve a mixture having a 220 cst kinematic viscosity (at
40.degree. C.), and then heated to 80-90.degree. C. in a stirred
vessel. Antioxidants were added and everything was mixed until a
clear solution was obtained. The formulations of compositions 1-17
as well as the hot plate test results (15 minute duration) are
shown below in Table 5.
TABLE-US-00005 TABLE 5 IRGANOX .RTM. IRGANOX .RTM. IRGANOX .RTM.
Vanlube Weight Liquid Percent Composition Vanlube 961 1010 L115
E201 PCX Loss Fraction Residue Deposit 1 0.50 0.50 0.50 0.50 0.50
22.9% 59.5% 17.6% 4.0 2 -- 0.50 0.50 0.50 -- 24.1% 57.0% 18.9% 4.0
3 0.50 0.50 0.50 -- -- 27.1% 53.6% 19.3% 4.5 4 0.50 0.50 -- 0.50 --
27.8% 53.0% 19.2% 4.5 5 0.50 -- 0.50 0.50 -- 29.8% 49.4% 20.8% 4.5
6 0.50 0.50 -- -- 0.50 32.5% 47.2% 20.3% 5.0 7 -- 0.50 0.50 -- 0.50
35.1% 43.2% 21.7% 5.0 8 0.25 0.25 0.25 0.25 0.25 36.0% 42.6% 21.4%
5.5 9 -- 0.50 -- 0.50 0.50 37.8% 40.6% 21.6% 5.5 10 -- -- 0.50 0.50
0.50 39.6% 36.9% 23.5% 6.0 11 0.50 -- -- 0.50 0.50 43.6% 33.5%
22.9% 6.5 12 0.50 -- 0.50 -- 0.50 44.0% 32.9% 23.1% 7.0 13 -- 0.50
-- -- -- 45.1% 31.0% 23.9% 6.5 14 0.50 -- -- -- -- 45.9% 28.8%
25.3% 6.5 15 -- -- 0.50 -- -- 46.7% 26.0% 27.3% 7.5 16 -- -- --
0.50 -- 47.6% 27.5% 24.9% 7.5 17 -- -- -- -- 0.50 51.1% 22.7% 26.2%
8.0
[0066] This data demonstrates that formulations with one
antioxidant perform at a level different from those containing at
least three antioxidants.
Example 5
Preparation and Evaluation of a Lubricant Composition
[0067] A food grade, high temperature lubricant was prepared by
mixing the ingredients in Table 6:
TABLE-US-00006 TABLE 6 Ingredient Amount (gms) Base oil of Example
1 450 Base oil of Example 2 1289 IRGANOX .RTM. L06 9 VANLUBE .RTM.
961 9 IRGANOX .RTM. 1010 9 IRGANOX .RTM. E201 18 IRGANOX .RTM. L115
9 IRGALUBE .RTM. 349 1.8 IRGALUBE .RTM. TPPT 3.6 CUVAN .RTM. 303
(corrosion 1.8 inhibitor)
[0068] Two high performing, non-food grade high temperature
lubricants were also evaluated as comparative examples:
LEXOLUBE.RTM. POE 220HT OCL and LEXOLUBE.RTM. CPE 220 OCL, both
from Inolex Chemical Company, Philadelphia, Pa. All three
lubricants were evaluated and the test results are shown in Table
7.
TABLE-US-00007 TABLE 7 Example 5 Lexolube .RTM. Lexolube .RTM.
Property Test Method Lubricant POE 220HT OCL CPE-220 OCL Kinematic
Viscosity@40.degree. C., cSt ASTM D-445 227 226 236 Kinematic
Viscosity @ 100.degree. C., ASTM D-445 19 19 27 cSt Flash Point,
.degree. C. ASTM D-92 321 308 310 Weight loss 4 hrs at 260.degree.
C. Oven pan test 3% 3% 3% Weight loss 20 hrs at 260.degree. C. Oven
pan test 41% 51% 23% Liquid fraction 20 hrs at 260.degree. C. Oven
pan test 28% 3% 0 Residue 20 hrs at 260.degree. C. Oven pan test
32% 46% 77% Evaporation Loss, %, 6.5 hrs at ASTM D-972 2 1.7 2
204.degree. C. Four-Ball Wear, 100.degree. C., 40 kg ASTM D- 0.48
0.48 0.45 load, 1200 rpm, one hour, mm 4172 Rotating Bomb Oxidation
Test ASTM D- 1034 1180 605 (RBOT), at 150.degree. C., min. 2272
[0069] The results demonstrate that the lubricant composition of
the invention provides overall greater stability in high
temperature tests than either comparative industrial lubricant.
Therefore, it is suitable for use in high temperature applications
and for obtaining the NSF International H1 ranking.
Example 6
Preparation and Evaluation of Food Grade Lubricant Grease
[0070] A food grade, high temperature lubricant grease having a
National Grease Lubricating Institute (NGLI) rating of 2 was
prepared. About two gallons of the lubricating composition of
Example 1 was charged to a laboratory scale stainless steel grease
mixer. Under continuous agitation, PTFE powder was slowly added; as
the amount of PTFE was increased, the grease became firmer. When
the amount of PTFE added was approximately 50% by weight of the
total composition, the grease had reached the consistency of NGLI
rating 2. Mixing was continued for an additional 30 minutes to
ensure homogeneity.
[0071] To evaluate the performance characteristics of the lubricant
grease composition, several commercial high temperature food grade
greases were obtained. Many of these products made commercial
claims to perform at temperatures between 300.degree. F. and
700.degree. F. Details of the sixteen comparative greases (CG) are
shown in Table 8.
TABLE-US-00008 TABLE 8 Comparative food grade grease samples Claim
Max ID NLGI # Oil Thickener Temperature CG01 2 Petroleum Al complex
500.degree. F. CG02 1 Petroleum Al complex 500.degree. F. CG03 2
Petroleum Al Complex 375.degree. F. CG04 2 Petroleum Aluminum
300.degree. F. CG05 2 Polyalphaolefin PTFE 400.degree. F. CG06 2
Polyalphaolefin Silica 700.degree. F. CG07 2 Polyalphaolefin
Silica/PTFE 650.degree. F. CG08 2 Vegetable Oil Al complex
500.degree. F. CG09 2 Polyalphaolefin PTFE 600.degree. F. CG10 2
Petroleum Ca Sulfonate 300.degree. F. CG11 2 Polyalphaolefin Ca
Sulfonate 360.degree. F. CG12 2 Petroleum Ca Sulfonate 360.degree.
F. CG13 2 Polyalphaolefin Al complex N/a CG14 2 Vegetable Oil Al
complex N/a CG15 2 Petroleum Ca Sulfonate N/a CG16 2
Polyalphaolefin Ca complex N/a
[0072] All of the commercial grease samples were compared to the
lubricant grease composition of the invention using the oven pan
test using cover pans to capture vapor deposits. Three tests were
performed at increasingly higher temperatures. The conditions were
20 hours at 400.degree. F. (204.degree. C.), 20 hours at
450.degree. F. (232.degree. C.) and 20 hours at 550.degree. F.
(288.degree. C.).
TABLE-US-00009 TABLE 9 Pan test conditions: 400.degree. F.
(204.degree. C.), 20 hours Weight Vapor Deposit ID Thickener
Stability Skinning Loss (mg) CG01 Liquid None 14% 0.7 CG02 Liquid
None 14% 0.4 CG03 Liquid None 11% 1.2 CG04 Liquid None 6% 0.8 CG05
No drop Slight skin 44% 1.2 CG06 No drop None 8% 1 CG07 No drop
None 8% 1.1 CG08 Liquid, polymerized Yes 11% 0.7 CG09 No drop, some
None 4% 0.4 bleed CG10 Liquid None 13% 0 CG11 No drop None 2% 0
CG12 No drop None 2% 0.3 CG13 Liquid None 9% 0.4 CG14 Liquid,
polymerized Yes 7% 0 CG15 No drop None 2% 0.4 CG16 No drop Slight
skin 6% 1.3 Lubrication No drop None 0% 0.1 Composition of the
Invention
[0073] The samples that did not survive at 400.degree. F. were not
tested at high temperatures.
TABLE-US-00010 TABLE 10 Pan test conditions: 450.degree. F.
(232.degree. C.), 20 hours Vapor Weight Deposit ID Thickener
Stability Skinning Loss (mg) CG05 No drop, shrunk Heavy skin 55%
2.4 CG10 Liquid None 23% 1.9 CG07 No drop Heavy skin 14% 1.8 CG16
No drop Heavy skin 11% 1.3 CG15 Sagged None 5% 1.5 CG09 No drop,
heavy bleed Slight skin 8% 0.5 CG12 No drop, some bleed Slight skin
5% 0.5 CG11 No drop None 5% 0.3 Lubrication No drop None 2% 0.1
Composition of the Invention
TABLE-US-00011 TABLE 11 Pan test conditions: 500.degree. F.
(260.degree. C.), 20 hours Vapor Weight Deposit ID Thickener
Stability Skinning Loss (mg) CG06 No drop, heavy deposit Solid 35%
27.2 CG07 No drop, heavy deposit Heavy skin 23% 17.7 CG16 No drop,
heavy bleed Heavy skin 15% 9.3 CG15 No drop, some bleed Heavy skin
12% 7.1 CG12 No drop, some bleed Heavy skin 11% 6.9 CG09 No drop,
heavy bleed Solid 16% 6.5 CG11 No drop, some bleed Heavy skin 11%
4.0 Lubrication No drop, some bleed No skin 10% 3.9 Composition of
the Invention
[0074] At all temperatures, the grease of the invention had the
lowest evaporation and vapor deposit. It also gave no skinning. By
all three measures, it showed better performance at high
temperature than the commercial high temperature food grade greases
tested.
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