Patent ID: 7972497

Claim:
A process to prepare a heat transfer oil, comprising: a. dewaxing a substantially paraffinic wax feed by hydroisomerization dewaxing using a shape selective intermediate pore size molecular sieve under hydroisomerization conditions including a hydrogen to feed ratio from about 712.4 to about 3562 liter H 2 /liter oil (about 4 to about 20 MSCF/bbl), whereby a lubricating base oil is produced, b. selecting one or more fractions of the lubricating base oil having: i. a pour point less than −9° C., ii. a 50 wt % boiling point greater than 566° C., iii. greater than 10 weight percent and less than 70 weight percent total molecules with cycloparaffinic functionality, wherein the one or more fractions have at least 31.2 wt % 1-unsaturations by FIMS, and iv. a ratio of weight percent molecules with monocycloparaffinic functionality to weight percent molecules with multicycloparaffinic functionality greater than 15; and c. blending the one or more fractions of the lubricating base oil with less than 0.2 wt % antifoam agent to prepare the heat transfer oil of an ISO viscosity grade selected from the group of ISO 10, ISO 15, ISO 22, ISO 46, ISO 68, ISO 100, ISO 150, and ISO 220.