Title of Invention

TRANSLUCENT LUBRICATING GREASE COMPOSITION

Abstract The lubricating grease composition disclosed herein ,comprises a translucent lithium grease comprising 3to 20 % by weight of a long chain fatty acid and or glycerides of long chain fatty acid, 1-15% of lithium hydroxide, 0-15 % by weight of water and or alcohol / glycols, 0.1 to 10 % by weight of complexing agent, 20-90% by weight of an oil selected from a group consisting of mineral and / or synthetic oils and 0.1 to 10 % of performance additives covering extreme pressure and anti-wear (EP-AW) additives , anti-oxidants, structure modifiers, rust inhibitors, etc. The methods disclosed herein describe the preparation of the translucent lithium grease by an open kettle and a pressure.
Full Text


4. DESCRIPTION
TRANSLUCENT LUBRICATING GREASE COMPOSITION
BACKGROUND OF THE INVENTION
This invention in general relates to the preparation of grease and specifically relates to the process of preparing translucent greases with lithium grease as a major component and additives as other components to meet specific requirements.
Best-emerged combinations in the class of general translucent greases have been observed to exhibit improved properties in appearance, shear and mechanical stability, anti-oxidation, low temperature properties, and longer life.
In the existing methods, metallic soaps, metallic complex soaps, and mixed soaps of Na, Al, Li, K, Ca, and Ba have been reported as thickeners in lubricating grease industry. Calcium base grease is considered to be the oldest known grease since horary past. Lithium base greases have really taken the lead and now have become most widely used greases and control over 70% of total worldwide market.
C.J.Boner in his book "Manufacture and Application of Lubricating Greases", has described different types of soaps as thickener base for greases namely Al, Ca, Na, Li, clay base, pigments, silica, etc. Complex soaps of these thickeners have also been cited with an objective of enhancing the performance of the greases. Many soaps prepared and cited by C.J.Boner have not gained commercial significance, may be due to availability, cost, requisite parameters, etc. For example, Knowles et al. (US Patent No. 2528373) prepared Beryllium soap in naphthenic oil. The resultant grease was a gel type grease, but formation of the soaps for greases is expensive and scarce. Lawrence, in J. of Ind.

Petroleum, Vol. 31, Pg. no. 303, Year 1945, listed the soaps of metals that do not thicken in oil. However some of the thickeners have indeed fetched the market and have their own characteristics, advantages and disadvantages. There are large numbers of patent references on lithium class of greases (US 2397956, US 2417428, US 2614077 US 5391,309, US 3681242, US 3791973, US 4435299, US 444669, US 4582619, and US 4597881). Majority of the references cited in literature delineate the process of preparing lithium base grease, different kinds of additives response of the grease, etc. McLennan in US Patent No. 2417428 described the composition of lithium soap base grease comprising lithium acetate in conjunction with lithium sperm oil soap and lithium stearate soap resulting in smooth, translucent, buttery grease which on cooling leads to the soft, unctuous consistency.
The majority of soap or complex soap thickeners of commercial significance for formulating lubricating greases are either metals derived from alkali or alkaline earth metals. In general, these thickeners are opaque and greases formulated from these thickeners are opaque in nature. However, greases formulated with Al-complex greases have shown some level of transparency, whereas soap base greases from lithium are completely opaque. The reason for their opaqueness is primarily attributed to the crystalline nature of the soap and low level of solvency in the formulating base oil.
In view of the foregoing discussion, there is a need for a translucent lithium base grease with the following properties: high drop point, shining smooth appearance, excellent mechanical and roll stability, good Extreme Pressure and Anti wear (EP-AW) properties, and low temperature characteristics.

SUMMARY OF THE INVENTION
The grease composition disclosed herein addresses the above mentioned need for a translucent lithium base grease with the following properties: high drop point, shining smooth appearance, excellent mechanical and roll stability, good Extreme Pressure and Anti - Wear (EP-AW) properties, and low temperature characteristics.
The lubricating grease composition disclosed herein, comprises lithium soap base grease containing 3-20% by weight of long chain fatty acid and/or glycerides of long chain fatty acid , 1-10% of lithium hydroxide, 0-15 % by weight of water and/or alcohol / glycols, 20-90% by weight of an oil selected from the group consisting of mineral and/or synthetic oils and 0.1 to 10 % of performance additives covering Extreme Pressure and Anti-Wear (EP-AW), anti¬oxidants, structure modifiers, rust inhibitors, etc.
Further, the lubricating grease composition disclosed herein comprises a lithium complex soap base grease that further comprises 3-20% by weight of long chain fatty acid and/or glycerides of long chain fatty, 1-10% of lithium hydroxide, 0-15 % by weight of water and/or alcohol/glycols, 0.1 to 10 % by weight of complexing agent namely , boric acid, salicylic acid, etc., 20-90% by weight of an oil selected from the group consisting of mineral and/or synthetic oils and or blends of mineral, and/or synthetic oils and 0.1 to 10 % of performance additives covering Extreme Pressure and Anti-Wear (EP-AW), anti-oxidants, structure modifiers, rust inhibitors, etc.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGURE 1 illustrates a first method of preparation of a translucent lubricating grease composition.

FIGURE 2 illustrates a second method of preparation of a translucent lubricating grease composition.
FIGURE 3A illustrates the physico-chemical characteristics of a lithium base grease prepared by an open kettle process.
FIGURE 3B illustrates the physico-chemical characteristics of a lithium complex grease.
FIGURE 3C illustrates the physico-chemical characteristics of a lithium complex grease with synthetic base oil.
FIGURE 3D illustrates the physico-chemical characteristics of a lithium base grease prepared by a pressure kettle process.
DETAILED DESCRIPTION OF THE DRAWINGS
FIGURE 1 illustrates a first method of preparation of a translucent lubricating grease composition in an open kettle process. The first method of preparation of a translucent lubricating grease composition comprises forming a mixture by adding together carboxylic acid or glyceride and mineral oil and /or synthetic oil to an open kettle 101, stirring and heating such a mixture to a temperature of 70 to 100 ° C 102, adding lithium hydroxide in full or partial quantity 103, adding water / and or alcohol or glycols thereto 0-15 % to form a thickened grease product either in full or partial quantity 104, maintaining the temperature of the thickened grease product for a predetermined duration 105, raising the temperature of the thickened grease product to 100 to 170 ° C 106, dehydrating and cooling the thickened grease product 107, and adding the other additives at 140 to 60 ° C 108 and then subjecting the mixture to the step of shearing by colloid mill / homogenizer 109 and/or deaerating the sheared mixture to obtain finished grease 110.

FIGURE 2 illustrates a second method of preparation of a translucent lubricating grease composition in a pressure kettle process. The second method of preparation of a translucent lubricating grease composition comprises providing a cooking vessel fitted with a high torque stirrer 200 of 20-120 rpm. The cooking vessel is charged with 3 to 20% by weight of fatty acid and/or their glycerides, and 10-50% of total oil 201. The charged mixture is vigorously agitated for 1 to 2 hours 202 and water is added as and when needed to propagate the grease forming reaction 203. The temperature of the charged mixture is now raised to 60 to 100° C 204 and is continuously agitated and held at 70 to 120° C for 1 to 2 hours 205, the temperature being raised further very slowly from 120 to 200 ° C, the duration of maintaining at temperature of 120 to 200 ° C is 1-3 hours 206. During the 1-3 hours period, the product gives grease structure and converts to thickened grease. The mixture is further cooled to 100 to 70° C 207, followed by addition of additives 208, and sheared with the help of colloid mill or homogenizer to interact with soap moiety and mineral oil for proper oil-soap bonding 209. The resulting product of NLGI No. 1 to 3 is obtained.
The mineral oils and synthetic oils or mixtures thereof may be used depending upon the particular grease being prepared. The mineral oil used in preparing the greases may be any conventionally refined base stocks derived from paraffinic, naphthenic and mixed base crudes. Synthetic oils that may be used include synthetic hydrocarbon such as polyalphaolefins in different viscosity grades such as PAO-2, PAO-4, PAO-6, PAO-8, PAO-10, PAO-40 and PAO-100.
The Extreme Pressure and Anti-Wear additives (EP-AW), structure modifiers additives and solid lubricants additives are selected from one or more of the following:
a. Extreme Pressure and Anti-Wear additives (EP-AW) additives: Antimony dialkyl dithiocarbamate, sulphurised fat, substituted dimercapto-thiadiazole, Zn dialkyl dithophosphate.

b. Rust inhibitor / metal deactivators: Ca-dinonylnaphthalenesulphonate,
Ba-petroleum sulphonate.
c. Anti-oxidants: Tert-butyl phenol, diphenyl amine derivative, para
cresol.
d. Structure Modifiers: Methacrylate-styrene copolymer, Ethylene-
propylene co-polymers.
In order to describe completely the nature of the lubricating grease disclosed herein, specific examples will be described hereinafter. However, the examples cited below are for the purpose of exemplary illustrations and is intended neither to restrict nor limit the scope of the claims.
Example 1:
The lithium base grease of Example 1 comprises ingredients with proportions as indicated below.

Long Chain Fatty acid and/ their glycerides 3-20 %
Lithium Hydroxide 1 -10%
Water 0.0-15 %
Total base oil (Mineral, Synthetic / blends) 75 - 90 %
Effective Li-soap 8-15 %
Additives 0.1-10%
The lithium base grease of Example 1 is prepared by the first method of preparation as described in the detailed description of FIGURE 1. The lithium

base grease thus prepared exhibits physico-chemical characteristics as listed in FIGURE 3A.
The lithium base grease of Example 1 demonstrates high drop point, shining smooth appearance, high mechanical and roll stability, good EP-AW properties.
Example 2:
In Example 2, a lithium complex grease is prepared similar to the lithium base grease of Example 1. However, the lithium complex grease additionally comprises boric acid as a complexing agent. The resultant lithium complex grease exhibits the physico-chemical characteristics as listed in FIGURE 3B
The lithium complex grease of Example 2 demonstrates high drop point and good EP-AW properties. The lithium complex grease of Example 2 indicates improved results in terms of transparency compared to conventional lithium complex grease and possesses high mechanical and roll stability.
Example 3:
Example 3 illustrates the preparation of a lithium complex grease with ingredients as indicated in Example 2. However, the base oil used in Example 3 is synthetic oil, for example polyalphaolefins, and other ingredients such as lithium Hydroxide, boric acid, long chain fatty acid, additives and water remain the same as the lithium complex grease of Example 2.
The lithium complex grease of Example 3 exhibits the physico-chemical characteristics listed in FIGURE 3C. The lithium complex grease of Example 3 demonstrates a high drop point, and EP-AW properties that fulfill the objective of a high temperature, heavy load grease.

Example 4:
Example 4 illustrates the preparation of a lithium base grease with composition as indicated in Example 1. However, the method of grease preparation is changed. The lithium base grease of Example 4 is prepared according to the second method of preparation as described in the detailed description of FIGURE 2, followed by transferring the obtained grease product to a finishing kettle, followed by adding balance oil and desired additives. The lithium base grease obtained by the procedure described above exhibits the physico-chemical properties as listed in FIGURE 3D.
The lithium base grease of Example 4 demonstrates high drop point, high mechanical stability, and significant reduction in process time.


5. CLAIMS
I claim:
1. A lubricating grease composition comprising:
a translucent lithium complex grease comprising:
3 to 20 % by weight of a long chain fatty acid and or glycerides of said long chain fatty acid;
1 to 15% of lithium hydroxide;
0 to 15 % by weight of water and or alcohol / glycols;
0.1 to 10 % by weight of complexing agent, wherein said complexing agent may be one of salicylic acid or boric acid;
20 to 90% by weight of an oil, wherein said oil is selected from a group consisting of mineral and / or synthetic oils; and
0.1 to 10 % of performance additives, wherein said additives are Extreme Pressure and Anti-Wear additives, anti-oxidants, structure modifiers and rust inhibitors.
2. A lubricating greases composition as claimed in claim 1, wherein said
translucent lithium complex grease is prepared by a pressure kettle process.
3. A lubricating grease composition as claimed in claim 1, wherein said mineral
base oil is one of a paraffinic oil, a naphthenic oil, and a combination thereof.

4. A lubricating grease composition as claimed in claim 1, wherein said lithium
complex grease is prepared using synthetic base oil consisting of
polyalphaolefins.
5. A lubricating grease composition as claimed in claim 1, wherein said translucent lithium complex grease is prepared using CI8 long chain fatty acids and 12 hydroxystrearic acid, hydrogenated castor oil.
6. A lubricating grease composition as claimed in claim 1, wherein said translucent lithium complex grease is prepared using extreme pressure, anti-wear, anti-oxidants, rust inhibitor, and structure modifiers.
7. A lubricating grease composition comprising:
a translucent lithium base grease comprising:
3 to 20 % by weight of a long chain fatty acid and or glycerides of said long chain fatty acid;
1 to 15% of lithium hydroxide;
0 to 15 % by weight of water and or alcohol / glycols;
20 to 90% by weight of an oil, wherein said oil is selected from a group consisting of mineral and / or synthetic oils; and
0.1 to 10 % of performance additives, wherein said additives are Extreme Pressure and Anti-Wear (EP-AW) additives, anti¬oxidants, structure modifiers and rust inhibitors.

8. A lubricating grease composition as claimed in claim 7, wherein said lithium base grease is prepared by an open kettle process.
9. A lubricating grease composition as claimed in claim 7, wherein said lithium base grease is prepared by a pressure kettle process.
10. A lubricating grease composition as claimed in claim 7, wherein said mineral
base oil is one of a paraffinic oil, a naphthenic oil, and a combination thereof.
11. A lubricating grease composition as claimed in claim 7, wherein said translucent lithium base grease is prepared using C18 long chain fatty acids and 12 hydroxystrearic acid, hydrogenated castor oil.
12. A lubricating grease composition as claimed in claim 7, wherein said translucent lithium base greases is prepared using extreme pressure, anti-wear, anti-oxidants, rust inhibitor, and structure modifiers.
13. A first method of preparing a lubricating grease composition, wherein said lubricating grease is one of a translucent lithium complex grease and a translucent lithium base grease, comprising the steps of:
forming a mixture by adding carboxylic acid or glyceride and mineral and/or synthetic oil to an open kettle;
stirring and heating said mixture to a temperature of 70 to 100 ° C;
adding lithium hydroxide in full or partial quantity;
adding water and/or alcohol or glycols thereto 0 to 15 %, to form a thickened grease product either in full or partial quantity;

maintain said temperature of said thickened grease product for a predetermined duration;
raising the temperature of the thickened grease product to 100 to 170 °C;
dehydrating and cooling the thickened grease product;
adding additives, wherein said additives are extreme pressure and anti-wear additives, anti-oxidants, structure modifiers, and rust inhibitors at the temperature 140 to 60 ° C;
subjecting the mixture to shearing by one of a colloid mill and a homogenizer; and
deaerating said sheared mixture to obtain finished grease.
14. A second method of preparing a lubricating grease composition, wherein said lubricating grease is one of a translucent lithium complex grease and a translucent lithium base grease, comprising the steps of:
providing a pressure vessel with a high torque stirrer of 20 to 120 revolutions per minute;
charging said cooking vessel with a mixture of 3 to 20% by weight of a fatty acid and/or glycerides of said fatty acid and 10 to 50% by weight of total oil, wherein said oil is selected from a group consisting of mineral and/or synthetic oils ;
agitating said charged mixture vigorously for 1 to 2 hours;

adding water to said agitated mixture for propagating grease forming reaction;
raising temperature of the agitated mixture to 60 to 100°C;
agitating the mixture continuously and holding the mixture at 70 to 120°Cforlto2hours;
raising temperature very slowly to 120 to 200 ° C, and maintaining at said temperature for 1 to 3 hours;
cooling the mixture to 100 to 70° C;
adding additives, wherein said additives are extreme pressure and Anti-wear additives, anti-oxidants, structure modifiers, and rust inhibitors; and
subjecting the mixture to shearing by one of a colloid mill and a homogenizer.
])

Documents:

1187-CHE-2007 AMENDED PAGES OF SPECIFICATION 26-10-2010.pdf

1187-CHE-2007 AMENDED CLAIMS 26-10-2010.pdf

1187-CHE-2007 EXAMINATION REPORT REPLY RECIEVED 26-10-2010.pdf

1187-CHE-2007 FORM-13 25-06-2007.pdf

1187-che-2007 description(complete).pdf

1187-che-2007 form-13.pdf

1187-che-2007-abstract.pdf

1187-che-2007-assignement.pdf

1187-che-2007-claims.pdf

1187-che-2007-correspondnece-others.pdf

1187-che-2007-description(provisional).pdf

1187-che-2007-drawings.pdf

1187-che-2007-form 1.pdf

1187-che-2007-form 26.pdf

1187-che-2007-form18.pdf


Patent Number 246208
Indian Patent Application Number 1187/CHE/2007
PG Journal Number 08/2011
Publication Date 25-Feb-2011
Grant Date 21-Feb-2011
Date of Filing 08-Jun-2007
Name of Patentee SIDDHARTH PETRO PRODUCTS
Applicant Address PLOT NO 13 SECTOR 3, IMT MANESAR GURGAON 122050 HARYANA
Inventors:
# Inventor's Name Inventor's Address
1 SUDHIR SACHDEVA PLOT NO 13 SECTOR 3, IMT MANESAR GURGAON 122050 HARYANA
PCT International Classification Number C10M129/26
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA