Patent ID: 7875458

Claim:
A method for determining, in real time, the suitability of basestock oils for use as the basestocks in the production of fully formulated lubricating oils meeting product low temperature viscometric properties, which method comprises: (a) selecting at least one low temperature viscometric property of the fully formulated lubricating oil selected from mini-rotary viscometer (MRV) viscosity, yield stress, Brookfield viscosity, cold cranking simulator (CCS) and pour point, (b) producing a training set by: (1) securing a sample of dewaxed basestock oil; (2) heating the basestock oil sample for a time and to a temperature sufficient to melt all the wax in the sample; (3) agitating the heated sample to insure homogeneity; (4) cooling the oil in a sample cell equipped with heating and cooling means and instrumented for the measurement of reflection of light or transmittance of light generated by a source, said cooling being to a selected target temperature in the range of between about 20° C. above the base oil specification pour point and about 5° C. below the base oil specification pour point; (4a) waiting for the sample and test cell to stabilize; (5) measuring the signal of scattered/reflected light off of or transmitted light through the sample at the temperature of step 4 after the stabilization period to secure a first intensity reading; (6) holding the sample at the target temperature of step 4 for from 1 minutes to 3 hours; (7) measuring the signal of scattered/reflected or transmitted light at the end of the hold time of step 6 to secure a second intensity reading and measuring any change in signal intensity (delta intensity of signal) between the first signal and the second signal reading; (8) formulating an oil product using the basestock and measuring the selected low temperature viscometric property or properties of step (a) associated with product quality; (9) repeating steps 1-8with one or more additional samples of the same or different dewaxed base stock oils using different target temperatures between 20° C. above and 5° C. below the specification pour point, as needed, until a relationship is observed between the delta intensity of signal and the selected low temperature formulated oil viscometric property or properties of choice; (10) correlating the delta intensity of signal to the selected low temperature viscometric property or properties; (c) subjecting a base oil to steps 1-8; (d) comparing the delta intensity of signal of the base oil of step (c) with the correlation data base to predict whether a formulated lubricating oil possessing the selected low temperature viscometric property or properties can be made using said base oil.