摘要:
The instant invention is directed to a method for producing a lubricating base stock having a preselected oxidative stability comprising the steps of: (a) separating, into a plurality of fractions based on molecular shape, a hydroisomerized hydrocarbon wax, (b) collecting the fractions of step (a) which have the preselected oxidative stability for use as a lubricating base stock, wherein the fractions to be collected are determined by measuring the oxidative stability of each of said fractions of said plurality of fractions to determine which fractions have said preselected oxidative stability. The invention is also directed to an improved lubricating base oil and a formulated lubricating composition using said lubricating base oil.
摘要:
The instant invention is directed to a process for producing an improved lubricating base stock having a preselected desired oxidation stability comprising the steps of: (a) hydroisomerizing a hydrocarbon wax to obtain a lubricating base stock, (b) irradiating, within the frequency of about 4600 to about 3500 cm.sup.-1 or about 1300 to about 600 cm.sup.-1, said lubricating base stock produced from hydroisomerization of said hydrocarbon wax, (c) measuring the absorption spectrum, within said frequency range of step (b), of said lubricating base stock using FT-IR, (d) converting said absorption spectrum into a number representative of the viscosity index of said lubricating base stock of step (a), (e) comparing the viscosity index produced in step (c) to a preselected viscosity index correlating to a preselected desired oxidative stability for said lubricating base stock of step (a), and then, (f) modifying said hydroisomerization of said hydrocarbon wax to increase the production of lubricating base stock having said preselected desired oxidative stability of step (e).
摘要:
A lubricant which is prepared from at least one synthetic ester composition exhibiting thermal and oxidative stability which comprises the reaction product of 3,5,5-trimethyl-1-hexanol and an acid or anhydride; and a lubricant additive package; whereby the incorporation of an antioxidant in the lubricant additive package for the purpose of maintaining oxidative and thermal stability of the crankcase lubricating oil formulation to at least 20 minutes as measured by HPDSC at 220.degree. C., 3.445 MPa air and 0.5 wt. % dioctyl diphenyl amine can be either reduced or eliminated. The synthetic ester composition preferably exhibits the following additional properties: a metals content of 10 ppm or less metals based on the total synthetic ester composition, an ash content of 15 ppm or less ash based on the total synthetic ester composition, a total acid number of 0.05 mg KOH/g or less, and a volume resistivity of at least about 1.times.10.sup.11 ohm cm.