Lubricating oil and uses thereof

Abstract

Herein disclosed is a lubricant oil or lubricant for the compressor of a refrigeration system which operates with a refrigerant comprising at least one component of the hydrocarbon (HC) group of refrigerants, (a) whereby the lubricant consists of at least 85 weight % of alkylbenzene having an average molecular weight of ≧160 g/mol and exhibiting a viscosity of 2.2-3.0 centistokes (cSt) at 40 deg C.; optionally wherein the alkylbenzene consists of at least 85 wt % of linear (straight chain) alkylbenzene, having an average molecular weight of ≧160 g/mol and exhibiting a viscosity of 2.2-3.0 centistokes (cSt) at 40 deg C.; (b) or alternatively whereby the lubricant consists of at least 85 weight % of alkylbenzene having an average molecular weight of ≧190 g/mol and having a viscosity of 2.5-3.5 cSt at 40 deg C.; optionally wherein the alkylbenzene consists of at least 85 wt % of linear (straight chain) alkylbenzene, having an average molecular weight of ≧190 g/mol and exhibiting a viscosity of 2.5-3.5 centistokes (cSt) at 40 deg C.

What is claimed is: 
     
         1 . A lubricant for the compressor of a refrigeration system which operates with a refrigerant comprising at least one component of the hydrocarbon (HC) group of refrigerants,
 (a) wherein the lubricant consists of at least 85 weight % of alkylbenzene having an average molecular weight of ≧160 g/mol and exhibiting a viscosity of 2.2-3.0 centistokes (cSt) at 40 deg C.; or alternatively   (b) wherein the lubricant consists of at least 85 weight % of alkylbenzene having an average molecular weight of ≧190 g/mol and having a viscosity of 2.5-3.5 cSt at 40 deg C.; or alternatively   (c) a combination of lubricant (a) and lubricant (b).   
     
     
         2 . The lubricant of  claim 1 (a) wherein the alkylbenzene consists of at least 85 wt % of linear (straight chain) alkylbenzene, having an average molecular weight of ≧160 g/mol and exhibiting a viscosity of 2.2-3.0 centistokes (cSt) at 40 deg C.; or alternatively
 the lubricant of  claim 1 (b) wherein the alkylbenzene consists of at least 85 wt % of linear (straight chain) alkylbenzene, having an average molecular weight of ≧190 g/mol and having a viscosity of 2.5-3.5 cSt at 40 deg C. 
 
     
     
         3 . The lubricant of  claim 1 , wherein the total number of carbon atoms in the alkylbenzene is in the range of 12-18, or alternatively in the range of 13-17, or alternatively in the range of 14-16. 
     
     
         4 . The lubricant of  claim 3  wherein the alkylbenzene alkyl chain consists entirely of a single alkyl chain length. 
     
     
         5 . The lubricant of  claim 4  wherein the alkylbenzene alkyl chain is 100 wt % C8, or C9, or C10, or greater than 50 wt % a single carbon number alkyl chain in the range of C8-C10 and less than 50 wt % other carbon numbers in the same range. 
     
     
         6 . The lubricant of  claim 1  wherein the number of alkyl groups in the alkylbenzene is 1-2. 
     
     
         7 . The lubricant of  claim 1  wherein the lubricant is
 a majority distillate component containing at least 95 weight % of linear alkylbenzene having an average molecular weight of ≧160 g/mol and exhibiting a viscosity of 2.2-3.0 centistokes (cSt) at 40 deg C., or alternatively 
 a majority distillate component of at least 95 weight % of linear alkylbenzene having an average molecular weight of ≧190 g/mol and having also a viscosity of 2.5-3.5 cSt at 40 deg C. 
 
     
     
         8 . The lubricant of  claim 1  wherein the refrigerant utilized in the refrigerant system comprises at least the refrigerant R600a or R290. 
     
     
         9 . A lubricant composition containing the lubricant of  claim 1  and up to 5 weight % of additives selected from those that provide improved antiwear properties, extreme pressure resistance, oxidation stability, corrosion inhibition, antifoaming, suppressant of pourpoint, improvement of viscosity index, and reduction of acid content. 
     
     
         10 . The lubricant of  claim 1 , wherein the lubricant demonstrates a kinematic viscosity at 40 deg C. of 2.2-3.5 cSt and exhibits full miscibility with refrigerant R600a or R290 over the entire temperature range of +60 deg C. to −60 deg C. 
     
     
         11 . The lubricant of  claim 10 , wherein the lubricant demonstrates a flashpoint of at least 112 deg C. 
     
     
         12 . The lubricant of  claim 1 , wherein the lubricant demonstrates a pourpoint of at least −40 deg C. or a dielectric strength of at least 25 kV. 
     
     
         13 . A method of using the lubricant of  claim 1 . 
     
     
         14 . The method of  claim 13  utilized in a refrigeration system's compressor. 
     
     
         15 . A method of using the lubricant composition of  claim 9 . 
     
     
         16 . The method of  claim 15  utilized in a refrigeration system's compressor. 
     
     
         17 . A compressor charged with the lubricant of  claim 1 . 
     
     
         18 . A compressor charged with the lubricant composition of  claim 9 . 
     
     
         19 . A refrigeration system comprising the lubricant of  claim 1  and a refrigerant selected from one component of the hydrocarbon class of refrigerants. 
     
     
         20 . A refrigeration system comprising the lubricant composition of  claim 9  and a refrigerant selected from one component of the hydrocarbon class of refrigerants.