Patent ID: 7641786

Claim:
A process for predicting the Mini Rotary Viscometer (MRV) properties of formulated oils based on paraffin distribution which comprises: (a) injecting a basestock sample into a first column of a 2-dimensional gas chromatograph, said first column being coated with a non-polar material to separate the basestock sample into a series of first dimension sample components having a first set of retention times; (b) injecting the separated first dimension sample components from step (a) into a second column coated with a semi-polar material to further separate the separated first dimension sample components into second dimension sample components having a second set of retention times; (c) subjecting the first and second sets of retention times to qualitative analysis to identify iso-paraffin components or groupings thereof and to quantitative analysis to identify the quantity of the iso-paraffin components having carbon numbers in the lubricant basestock range; (d) grouping the iso-paraffin components into x groupings where x is a number from 0 to 3 for each identified individual lube paraffins in the carbon number range from 16 to 505; (e) selecting a lower carbon number n and an upper carbon number m; (f) identifying a first, second and third iso-paraffin group A, B and C for each individual carbon number over the range from n to m; (g) calculating an isoparaffin Index by the formula: Isoparaffin ⁢ ⁢ Index = ∑ L = n m ⁢ ( IP A ) L ∑ L = n m ⁢ ( IP B ) L + ∑ L = n m ⁢ ( IP C ) L and; (h) comparing the calculated Isoparaffin Index to the Isoparaffin Index calculated for standard samples of known MRV wherein the standard samples Isoparaffin Index is a value of about 0.8 or less.