Fluorinated polyacrylate antifoam components for lubricating compositions
There is disclosed an antifoam component for a mechanical device which includes a fluorinated poly(acrylate) copolymer. The antifoam component has improved foam performance and thermal stability in finished fluids, such as driveline fluids.
1. A method of improving the foam reduction performance of a lubricating composition in the presence of silicone-based form-in-place gasket material, said method comprising:
adding an antifoam component to a form a lubricating composition, wherein said lubricating composition comprises:
a) an oil of lubricating viscosity selected from the group consisting of a Group II oil, a group II+ oil having a viscosity index greater than or equal to 110 and less than 120, Group III oil, a Group IV oil, a Group V, or mixtures thereof; and
b) said antifoam component comprising a poly(acrylate) copolymer including:
(i) from about 50 wt % up to about 72 wt % of an acrylate monomer having C 4 to C 8 alkyl esters of acrylic acid;
(ii) from about 10 wt % up to about 31 wt % of an acrylate comonomer having C 2 to C 3 alkyl esters of acrylic acid; and
(iii) from about 7.0 wt % up to 20 wt % of a fluorinated (meth)acrylate monomer selected from the group consisting of 2,2,2-trifluoroethyl (meth)acrylate, 1,1,1,3,3,-hexafluoroisopropyl (meth)acrylate, octafluoropentyl (meth)acrylate, heptadecafluoroundecyl (meth)acrylate, tridecafluorooctyl (meth)acrylate, or 2,2,3,4,4,4-hexaflurobutyl (meth)acrylate;
the antifoam component having a M w of at least 45,000 Daltons.
2. The lubricating composition of claim 1 , wherein the acrylate monomer (i) is present in an amount of about 54 wt % to about 72 wt %, and the acrylate comonomer (ii) is present in an amount of about 31 wt % to about 23 wt %.
3. The lubricating composition of claim 1 , wherein the acrylate monomer (i) comprises 2-ethylhexyl acrylate.
4. The lubricating composition of claim 1 , wherein the comonomer (ii) comprises ethyl acrylate or propyl acrylate.
5. The lubricating composition of claim 1 , wherein the acrylate monomer (i) is 2-ethylhexyl acrylate and the acrylate comonomer (ii) is ethyl acrylate.
6. The lubricating composition of claim 1 , wherein the antifoam component has a M w of from about 45,000 Da to about 80,000 Da.
7. The lubricating composition of claim 1 , wherein the antifoam component is present in the lubricating composition in an amount of at least 10 ppm.
8. The lubricating composition of claim 1 further comprising at least one further additive selected from the group consisting of dispersants, viscosity modifiers, supplemental friction modifiers, detergents, antioxidants, seal swell agents, and anti-wear agents.
9. A method of lubricating a mechanical device comprising supplying to the mechanical device the lubricating composition of claim 1 .
10. The method of claim 9 wherein the mechanical device comprises a driveline device.
11. The method of claim 10 wherein the driveline device comprises an axle, a gear, a gearbox or a transmission.
12. The method of claim 9 wherein the mechanical device comprises an internal combustion engine.
13. The method of claim 9 , wherein the mechanical device comprises a hydraulic system, a turbine system, a circulating oil system, a refrigeration lubricant system, or an industrial gear.