Gelling agent for calcium sulfonate greases
A calcium sulfonate grease is formed from a base oil of lubricating viscosity, an oil-soluble overbased calcium sulfonate or precursors therefor, a conversion acid, water, and a gelling agent, which is selected from branched aliphatic diols with at least eight carbons, and mixtures thereof.
1 . A calcium sulfonate grease formed from a base oil of lubricating viscosity, an oil-soluble overbased calcium sulfonate or precursors therefor, a conversion acid, and a gelling agent, which is selected from branched aliphatic diols with at least eight carbons and mixtures thereof.
2 . The calcium sulfonate grease of claim 1 , wherein the gelling agent is selected from branched aliphatic diols with eight to ten carbons.
3 . The calcium sulfonate grease of claim 1 , wherein the gelling agent is selected from branched aliphatic diols with eight carbons, branched aliphatic diols with nine carbons, and mixtures thereof.
4 . The calcium sulfonate grease of claim 1 , wherein the gelling agent comprises at least one of the group consisting of 2-ethyl-1,3-hexanediol, 2-butyl-2-ethyl-propanediol, 2,5-dimethyl-2,5-hexanediol, and combinations thereof.
5 . The calcium sulfonate grease of claim 1 , wherein the gelling agent is at least 0.5 wt. % of a total weight of the base oil, the oil-soluble overbased calcium sulfonate or precursors therefor, the conversion acid, and the gelling agent.
6 . The calcium sulfonate grease of claim 1 , wherein the oil-soluble overbased calcium sulfonate has a total base number (TBN) of at least 300 mg KOH/g eq, as measured according to ASTM D2896.
7 . The calcium sulfonate grease of claim 1 , wherein the oil-soluble overbased calcium sulfonate comprises a calcium salt of a sulfonic acid selected from alkyl sulfonic acids, aryl sulfonic acids, alkyl aryl sulfonic acids and mixtures thereof.
8 . The calcium sulfonate grease of claim 1 , wherein the oil-soluble overbased calcium sulfonate comprises a calcium salt of a sulfonic acid comprising at least 10 aliphatic carbon atoms.
9 . The calcium sulfonate grease of claim 1 , wherein the oil-soluble overbased calcium sulfonate is at least 3 wt. % of a total weight of the base oil, the oil-soluble overbased calcium sulfonate or precursors therefor, the conversion acid, and the gelling agent.
10 . The calcium sulfonate grease of claim 1 , wherein the conversion acid is selected from an alkylbenzene sulfonic acid with an aliphatic chain of between 8 and 36 carbon atoms, a succinic acid with an aliphatic chain of between 8 and 36 carbon atoms, a succinic acid with an alkyl or alkenyl group on the C2 or C3 of the succinic acid with an aliphatic chain of between 8 and 36 carbon atoms, and mixtures thereof.
11 . The calcium sulfonate grease of claim 1 , wherein the conversion acid is at least 1 wt. % of a total weight of the base oil, the oil-soluble overbased calcium sulfonate or precursors therefor, the conversion acid, and the gelling agent.
12 . The calcium sulfonate grease of claim 1 , wherein the base oil of lubricating viscosity is at least 40 wt. % of a total weight of the base oil, the oil-soluble overbased calcium sulfonate or precursors therefor, the conversion acid, and the gelling agent.
13 . The calcium sulfonate grease of claim 1 , wherein the calcium sulfonate grease is further formed from water, wherein the water is added at 2-25 parts by weight, based on a total weight of the base oil, the oil-soluble overbased calcium sulfonate or precursors therefore, the conversion acid, and the gelling agent.
14 . The calcium sulfonate grease of claim 1 , wherein the calcium sulfonate grease is a calcium sulfonate complex grease and wherein the calcium sulfonate complex grease is further prepared from at least one of a complexing agent and a saponification agent.
15 . The calcium sulfonate complex grease of claim 14 , wherein the complexing agent is selected from the group consisting of a long chain carboxylic acid or calcium salt thereof, a short chain carboxylic acid or calcium salt thereof, boric acid, salts thereof, and organic boron compounds, phosphoric acid, sulfonic acid and mixtures thereof.
16 . The calcium sulfonate complex grease of claim 14 , wherein the saponification agent is selected from the group consisting of calcium oxide calcium hydroxide, calcium carbonate, and mixtures thereof.
17 . A method for lubricating a device comprising applying the calcium sulfonate grease of claim 1 to the device.
18 . A method of forming a calcium sulfonate grease comprising:
combining a base oil of lubricating viscosity, an oil-soluble overbased calcium sulfonate or precursors therefor, a conversion acid, a gelling agent, and water to form a mixture, wherein the gelling agent is selected from branched aliphatic diols with at least eight carbons, and mixtures thereof; and
heating the mixture to a gelation temperature at which the mixture forms a gel.
19 . The method of claim 18 , further comprising incorporating at least one of a complexing agent and a saponification agent into the gel to form a calcium sulfonate complex grease.
20 . A formulation for forming a calcium sulfonate grease comprising:
3-20 wt. % of an overbased calcium sulfonate;
1-12 wt. % of a conversion acid;
2.5-6 wt. % of a gelling agent, which is selected from branched aliphatic diols with at least eight carbons and mixtures thereof;
2-25 wt. % of water; and
at least 30 wt. % of a base oil.