Engine oil lubricant compostions and methods for making same with steel corrosion protection

Abstract

Provided is a low sulfated ash engine oil lubricant composition containing organic friction modifiers with improved fuel economy and corrosion resistance. The lubricant composition includes one or more metal free corrosion inhibitors having an organic acid group and/or one or more organo metallic naphthalene molecules having a ASTM D2896 total base number less than 3 mg KOH/g. The resulting lubricant composition improves ASTM D6557 corrosion protection for low sulfated ash engine oils containing organic friction modifiers, while maintaining exceptional fuel economy performance.

What is claimed is: 
     
         1 . An engine oil lubricant composition, comprising:
 about 40 wt % to about 90 wt % of at least one base oil;   about 0.1 wt % to about 5 wt % of an organic friction modifier;   about 1 wt % to about 6 wt % of at least one detergent comprising magnesium or calcium;   about 0.01 wt % to about 1 wt % of a corrosion inhibitor having at least one organic acid moiety or organic salt thereof;   wherein the engine oil lubricant composition has a sulfated ash content of 0.5 wt % or less, and an HTHS (ASTM D4683) of less than or equal to 3.7 cP at 150° C.   
     
     
         2 . The lubricant composition of  claim 1 , wherein the composition comprises 0.1 wt % to about 1.0 wt % of an organic friction modifier. 
     
     
         3 . The lubricant composition of  claim 1 , wherein the organic friction modifier is an alkyl or alkylene glyceride ester. 
     
     
         4 . The lubricant composition of  claim 1 , wherein the at least one detergent comprises magnesium or calcium sulfonate or a mixture thereof. 
     
     
         5 . The lubricating engine oil of  claim 1 , wherein the corrosion inhibitor having a naphthenate, naphthalene sulfonate, or at least one organic acid or organic salt moiety improves the ball rust test (ASTM D6557) average gray value (AGV) by at least 25%. 
     
     
         6 . The lubricating engine oil of  claim 1 , wherein the corrosion inhibitor having a naphthenate, naphthalene sulfonate, or at least one organic acid or organic salt moiety improves the ball rust test (ASTM D6557) average gray value (AGV) by at least 50%. 
     
     
         7 . The lubricating engine oil of  claim 1 , wherein the corrosion inhibitor having a naphthenate, naphthalene sulfonate, or at least one organic acid or organic salt moiety improves the ball rust test (ASTM D6557) average gray value (AGV) by at least 100%. 
     
     
         8 . The lubricating engine oil of  claim 1 , wherein the corrosion inhibitor having at least one organic acid or organic salt of an alkyl or alkylene substituted naphthenate or naphthalene sulfonate moiety. 
     
     
         9 . The lubricating engine oil of  claim 1 , wherein the corrosion inhibitor is zinc naphthenate. 
     
     
         10 . The lubricating engine oil of  claim 1 , wherein the corrosion inhibitor is the barium salt of dinonyl, naphthylenesulfonic acid. 
     
     
         11 . The lubricating engine oil of  claim 1 , wherein the corrosion inhibitor is calcium dinonylnaphthalene sulfonate. 
     
     
         12 . The lubricating engine oil of  claim 1 , wherein the corrosion inhibitor is zinc dinonylnaphthalene sulfonate. 
     
     
         13 . The lubricating engine oil of  claim 1 , wherein the corrosion inhibitor having at least one organic acid or organic salt of a carboxylate moiety. 
     
     
         14 . The lubricating engine oil of  claim 1 , wherein the corrosion inhibitor is the imidazoline reaction product of oleic acid and amino-ethyl 2-ethylhexyl amine plus free oleic acid. 
     
     
         15 . The lubricating engine oil of  claim 1 , wherein the corrosion inhibitor is a sixteen carbon chain alkylated succinic anhydride reacted with 1,3 propane diol. 
     
     
         16 . The lubricating engine oil of  claim 1 , wherein the corrosion inhibitor having at least one organic salt moiety with a counter ion from the alkali, alkaline earth, transition metal, metalloid, or post transition metal groups. 
     
     
         17 . The lubricating engine oil of  claim 1 , wherein the corrosion inhibitor having at least one organic salt moiety with a calcium, magnesium, lithium, sodium, barium, zinc, or copper counter ion. 
     
     
         18 . An engine oil lubricant composition, comprising:
 about 40 wt % to about 90 wt % of at least one base oil;   about 0.1 wt % to about 5 wt % of an organic friction modifier;   about 1 wt % to about 6 wt % of at least one detergent comprising magnesium or calcium;   about 0.01 wt % to about 1 wt % of a corrosion inhibitor comprising an organo-metallic naphthalene compound;   wherein the engine oil lubricant composition has a sulfated ash content of 0.5 wt % or less, and an HTHS (ASTM D4683) of less than or equal to 3.7 cP at 150° C.   
     
     
         19 . The lubricating engine oil of  claim 18 , wherein the corrosion inhibitor having at least one organic acid or organic salt of an alkyl or alkylene substituted naphthenate or naphthalene sulfonate moiety. 
     
     
         20 . The lubricating engine oil of  claim 18 , wherein the corrosion inhibitor is selected from zinc naphthenate, the barium salt of dinonylnaphthylenesulfonic acid, calcium dinonylnaphthalene sulfonate, and zinc dinonylnaphthalene sulfonate.