Metalworking fluid compositions and preparation thereof

Abstract

A metalworking fluid composition comprising an isomerized base oil having consecutive numbers of carbon atoms and less than 10 wt % naphthenic carbon by n-d-M is provided. The metalworking fluid has reduced mist formation, low foaming tendency and excellent air release properties, and excellent wear properties.

1 . A metalworking fluid, which demonstrates resistance to wear comprising:
 a lubricant base oil having consecutive numbers of carbon atoms and less than 10 wt % naphthenic carbon by n-d-M, said base oil further comprising at least 70% of Fischer-Tropsch derived base oils; and   0.10 to 10 wt. %. of at least an additive selected from the group of a metalworking fluid additive package; metal deactivators; corrosion inhibitors; antimicrobial; anticorrosion; extreme pressure agents; antifriction; antirust agents; polymeric substances; anti inflammatory agents; bactericides; antiseptics; antioxidants; chelating agents such as edetic acid salts, and the like; pH regulators; antiwear agents; and mixtures thereof   wherein the metalworking fluid has an average mist accumulation rate of less than 300 mg/mm3 within 30 seconds after start as measured in an aerosol mist formation test.   
     
     
         2 . The metalworking fluid of  claim 1 , wherein the metalworking fluid has an average mist accumulation rate of less than 250 mg/mm3 within 30 seconds as measured in an aerosol mist formation test. 
     
     
         3 . The metalworking fluid of  claim 2 , wherein the metalworking fluid has an average mist accumulation rate of less than 150 mg/mm3 within 30 seconds as measured in an aerosol mist formation test. 
     
     
         4 . The metalworking fluid of  claim 1 , wherein the metalworking fluid has an average mist accumulation rate of less than 150 mg/mm3 within 60 seconds as measured in an aerosol mist formation test. 
     
     
         5 . The metalworking fluid of  claim 1 , wherein the metalworking fluid has a biodegradability of at least 30% as measured according to OECD 301D. 
     
     
         6 . The metalworking fluid of  claim 1 , wherein the lubricating base oil is a Fischer-Tropsch derived base having a kinematic viscosity at 100° C. between 2 mm2/s and 6 mm2/s; a kinematic viscosity at 40° C. between 7 mm2/s and 20 mm2/s; a viscosity index of 120-150; pour point in the range of −20 and −50° C.; molecular weight of 300-500; density in the range of 0.800 to 0.820; paraffinic carbon in the range of 93-97%; naphthenic carbon in the range of 3-7%; Oxidator BN of 30 to 60 hours; and Noack volatility in wt. % of 8 to 60 as measured by ASTM D5800-05 Procedure B. 
     
     
         7 . The metalworking fluid of  claim 1 , wherein the lubricating base oil is a Fischer-Tropsch derived base oil: a kinematic viscosity at 100° C. between 5 mm2/s and 7 mm2/s; a kinematic viscosity at 40° C. between 25 mm2/s and 50 mm2/s; a viscosity index of 140-160; pour point in the range of −15 and −25° C.; molecular weight of 450-550; density in the range of 0.820 to 0.830; paraffinic carbon in the range of 90-95%. 
     
     
         8 . The metalworking fluid of  claim 1 , wherein the lubricant base oil has an average molecular weight between 600 and 1100, and an average degree of branching in the molecules between 6.5 and 10 alkyl branches per 100 carbon atoms. 
     
     
         9 . The metalworking fluid of  claim 1 , wherein the lubricant base oil has a wt. % Noack volatility between 0 and 100. 
     
     
         10 . The metalworking fluid of  claim 1 , wherein the lubricant base oil has an auto-ignition temperature (AIT) greater than an amount defined by: 1.6*(Kinematic Viscosity at 40° C., in mm2/s)+300. 
     
     
         11 . The metalworking fluid of  claim 1 , wherein the lubricant base oil has an auto-ignition temperature (AIT) greater than 329° C. 
     
     
         12 . The metalworking fluid of  claim 1 , wherein the lubricant base oil has a viscosity index greater than 28*Ln(Kinematic Viscosity at 100° C., in mm2/s)+300. 
     
     
         13 . The metalworking fluid of  claim 1 , wherein the lubricant base oil has a ratio of weight percent molecules with monocycloparaffinic functionality to weight percent molecules with multicycloparaffinic functionality of greater than 15. 
     
     
         14 . The metalworking fluid of  claim 1 , wherein the lubricant base oil has a total weight percent of molecules with cycloparaffinic functionality of greater than 10, and a ratio of weight percent molecules with monocycloparaffinic functionality to weight percent molecules with multicycloparaffinic functionality of greater than 15. 
     
     
         15 . The metalworking fluid of  claim 1 , wherein the lubricant base oil has a Kinematic Viscosity at 100° C. of >1.808 mm2/s and a Noack volatility less than an amount calculated by: 1.286+20 (kv100)−1.5+551.8 e−kv100, where kv100 is the kinematic viscosity at 100° C. 
     
     
         16 . The metalworking fluid of  claim 1 , wherein the lubricant base oil comprises greater than 3 weight % molecules with cycloparaffinic functionality and less than 0.30 weight percent aromatics. 
     
     
         17 . The metalworking fluid of  claim 1 , wherein the lubricant base oil is greater than 10 wt. % and less than 70 wt. % total molecules with cycloparaffinic functionality. 
     
     
         18 . The metalworking fluid of  claim 1 , wherein the lubricant base oil has a traction coefficient of less than 0.023 when measured at a kinematic viscosity of 15 mm2/s and at a slide to roll ratio of 40%. 
     
     
         19 . The metal working fluid of  claim 1 , wherein the wear scar diameter is less than 0.75 mm. 
     
     
         20 . A method for lubricating a workpiece in a metalworking operation, the method comprising: supplying to the workpiece a composition comprising a lubricant base oil having consecutive numbers of carbon atoms and less than 10 wt % naphthenic carbon by n-d-M said base oil further comprising at least 70% of Fischer-Tropsch derived base oils; and
 0.10 to 10 wt. %. of at least an additive selected from the group of a metalworking fluid additive package; metal deactivators; corrosion inhibitors; antimicrobial; anticorrosion; extreme pressure agents; antifriction; antirust agents; polymeric substances; anti inflammatory agents; bactericides; antiseptics; antioxidants; chelating agents such as edetic acid salts, and the like; pH regulators; antiwear agents; and mixtures thereof,   wherein the lubricating base oil imparts aerosol control or particulate control to the composition for the composition to have an average mist accumulation rate of less than 300 mg/mm3 within 30 seconds after start as measured in an aerosol mist formation test.   
     
     
         21 . The method of  claim 20 , wherein the metalworking fluid has an average mist accumulation rate of less than 250 mg/mm3 within 30 seconds after start as measured in an aerosol mist formation test. 
     
     
         22 . The method of  claim 20 , wherein metalworking fluid has a biodegradability of at least 30% as measured according to OECD 301D. 
     
     
         23 . The method of  claim 20 , wherein the lubricant base oil is a Fischer-Tropsch derived base oil made from a waxy feed, and having a kinematic viscosity at 100° C. between 2 mm2/s and 3 mm2/S; a kinematic viscosity at 40° C. between 7 mm2/s and 12 mm2/s; a viscosity index of 120-140; pour point in the range of −30 and −50° C.; molecular weight of 300-500; density in the range of 0.800 to 0.820; paraffinic carbon in the range of 93-97%; naphthenic carbon in the range of 3-7%; Oxidator BN of 30 to 60 hours; and Noack volatility in wt. % of 10 to 60 as measured by ASTM D5800-05 Procedure B.