Tractor hydraulic fluid compositions and preparation thereof

Abstract

A tractor hydraulic fluid composition is prepared from an isomerized base oil which: a) the product itself, its fraction, or feed originates from or is produced at some stage by isomerization of a waxy feed from a Fischer-Tropsch process (“Fischer-Tropsch derived base oils”); or b) made from a substantially paraffinic wax feed (“waxy feed”). In one embodiment, the tractor hydraulic fluid composition is characterized as having a reduced level of viscosity modifier in an amount of 0 to 10 wt. %, and a Brookfield viscosity at −35° C. of less than 70,000 mPa.s.

1 . A tractor hydraulic fluid composition comprising (i) a lubricating base oil; (ii) from 0 to 10 wt % of a viscosity modifier; and (iii) 0-10 wt % of at least an additive package; wherein
 the lubricating base oil consists essentially of at least an isomerized base oil having consecutive numbers of carbon atoms and less than 7.5 wt % naphthenie carbon by n-d-M; and   the tractor hydraulic fluid composition has a Brookfield viscosity of less than 70,000 mPa.s at −35° C., and a kinematic viscosity of at least 7.0 mm 2 /s. at 100° C.   
   
   
       2 . The tractor hydraulic fluid composition of  claim 1 , additionally having a viscosity index of greater than 130. 
   
   
       3 . The tractor hydraulic fluid composition of  claim 1 , additionally having a viscosity index of greater than 150. 
   
   
       4 . The tractor hydraulic fluid composition of  claim 1 , comprising from 0.5 to 5 wt %. of a viscosity modifier, 
   
   
       5 . The tractor hydraulic fluid composition of  claim 1 , comprising from 1 to 3 wt %. of a viscosity modifier. 
   
   
       6 . The tractor hydraulic fluid composition of  claim 1 , wherein the lubricating base oil has a kinematic viscosity at 100° C. in the range of 1 and 15 mm 2 /s and a Noack volatility less than an amount defined by the equation: 900×(kinematic viscosity at 100° C.) −2.8 . 
   
   
       7 . The tractor hydraulic fluid composition of  claim 1 , wherein the lubricating base oil additionally includes a Pour Point Reducing Blend Component with 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. 
   
   
       8 . The tractor hydraulic fluid composition of  claim 1 , wherein the lubricating base oil has a traction coefficient less than 0.023, measured at a viscosity of 15 mm 2 /s and a slide to roil ratio of 40%. 
   
   
       9 . The tractor hydraulic fluid composition of  claim 1 , wherein the tractor hydraulic fluid composition has a Brookfield viscosity of less than 50,000 mPa.s at −35° C. 
   
   
       10 . The tractor hydraulic fluid composition of  claim 1 , wherein the tractor hydraulic fluid composition has a Brookfield viscosity of less than 40,000 mPa.s at −35° C. 
   
   
       11 . The tractor hydraulic fluid composition of  claim 1 , wherein the tractor hydraulic fluid composition has a Brookfield viscosity of less than 20,000 mPa.s at −40° C. 
   
   
       12 . The tractor hydraulic fluid composition of  claim 1 , wherein the tractor hydraulic fluid composition comprises at least a pour point depressant selected from the group of polymethacrylates; polyacrylates; polyacrylamides; condensation products of haloparaffin waxes and aromatic compounds; vinyl carboxylate polymers; terpolymers of dialkylfumarates, vinyl esters of fatty acids, and alkyl vinyl ethers; and mixtures thereof. 
   
   
       13 . The tractor hydraulic fluid composition of  claim 1 , wherein the additive package comprises at least an antioxidant selected from the group consisting of phenolies, aromatic amines, compounds containing sulfur and phosphorus, organosulfur compounds, organophosphorus compounds, and mixtures thereof. 
   
   
       14 . The tractor hydraulic fluid composition of  claim 1 , wherein the viscosity modifier is selected from the group of: ethylene-propylene copolymers; styrene-isoprene copolymers; hydrated styrene-isoprene copolymers; poly alkyl (meth) acrylates; functionalized poly alkyl (meth) acrylates; a polyisobutylene having a weight average molecular weight ranging from 700 to 2,500; a graft copolymer comprising a polymer backbone which has been grafted by reacting the polymer backbone with a reactant comprising N-p-diphenylamine,1,2,3,6-tetrahydrophthalimide; 4-anilinophenyl methacrylamide; 4-anilinophenyl maleimide; 4-anilinophenyl itaconamide; an acrylate or methacrylate ester of 4-hydroxydiphenylamine; a reaction product of p-aminodiphenylamine or p-alkylaminodiphenylamine with glycidyl methacrylate; a reaction product of p-aminodiphenylamine with isobutyraldehyde, a derivative of p-hydroxydiphenylamine; a derivative of phenothiazine; a vinylogous derivative of diphenylamine; and mixtures thereof. 
   
   
       15 . The tractor hydraulic fluid composition of  claim 14 , wherein the viscosity modifier is selected from the group consisting of ethylene-propylene copolymers; styrene-isoprene copolymers; hydrated styrene-isoprene copolymers; poly alkyl (meth) acrylates; functionalized poly alkyl (meth) acrylates; and mixtures thereof. 
   
   
       16 . The tractor hydraulic fluid composition of  claim 1 , wherein the additive package comprises at least a metal detergent selected from an oil-soluble neutral or overbased salt of alkali or alkaline earth metal made from one or more of: (1) a sulfonic acid, (2) a carboxylic acid, (3) a salicylic acid, (4) an alkyl phenol, (5) a sulfurized alkyl phenol, (6) an organic phosphorus acid characterized by at least one direct carbon-to-phosphorus linkage; and (7) mixtures thereof. 
   
   
       17 . The tractor hydraulic fluid composition of  claim 1 , wherein the isomerized base oil is a Fischer-Tropsch derived base oil. 
   
   
       18 . The tractor hydraulic fluid composition of  claim 1 , wherein the isomerized base oil is made from a substantially paraffinic wax feed. 
   
   
       19 . The tractor hydraulic fluid composition of  claim 1 , wherein the additive package comprises a Universal Tractor Transmission Oil (UTTO) additive package. 
   
   
       20 . The tractor hydraulic fluid composition of  claim 1 , wherein the additive package comprises a Super Tractor Oil Universal (STOU) additive package. 
   
   
       21 . A method for producing a tractor hydraulic fluid composition having a Brookfield viscosity of less than 70,000 cP at −35° C., and a kinematic viscosity of at least 7.0 mm 2 /s at 100° C., the method comprising blending (i) a lubricating base oil having consecutive numbers of carbon atoms and less than 7.5: wt % naphthenie carbon by n-d-M; with (ii) from 0 to 10 wt % of a viscosity modifier; and (iii) 0-10 wt % of at least an additive package. 
   
   
       22 . A method for producing a tractor hydraulic fluid composition of  claim 21 , wherein the lubricating base oil has less than 5 wt % naphthenie carbon. 
   
   
       23 . The method for producing a tractor hydraulic fluid composition of  claim 21 , wherein the lubricating base oil has a viscosity index greater than 130. 
   
   
       24 . The method for producing a tractor hydraulic fluid composition of  claim 21 , wherein the lubricating base oil is Fischer-Tropsch derived. 
   
   
       25 . A process for lubricating equipment, comprising:
 supplying to a fluid reservoir of an off-highway mobile equipment a tractor hydraulic fluid composition comprising (i) a lubricating base oil; (ii) from 0 to 10 wt % of a viscosity modifier; and (iii) 0-10 wt % of at least an additive package; wherein   the lubricating base oil consists essentially of at least an isomerized base oil having consecutive numbers of carbon atoms and less than 7.5 wt % naphthenie carbon by n-d-M; and   the tractor hydraulic fluid composition has a Brookfield viscosity of less than 70,000 mPa.s at −35° C., and a kinematic viscosity of at least 7.0 mm 2 /s, at 100° C.