润滑科技信息平台

Polyester lubricant for working fluids comprising difluoromethane

专利摘要

Mixtures of select neopentyl polyol esters are found to be highly miscible with the refrigerant R-32 over a wide temperature range. Working fluids are provided comprising R-32 and a lubricant containing these select neopentyl polyol esters and having a kinematic viscosity at 40° C. of 32 cSt or higher. Specifically, the lubricant composition of the invention comprises a mixture of alkylcarboxy esters of neopentyl polyols, wherein at least 10 wt % of all neopentyl polyol esters are esters of pentaerythritol oligomers of 4 or more pentaerythritol monomer groups, and wherein a majority of the alkylcarboxylate groups of the alkylcarboxy esters of neopentyl polyols are pentanoyl groups wherein at least 15% of the pentanoyl groups are branched. ......

基本信息

专利类型:
发明专利
申请/专利号:
US13/767058
申请日期:
2013-02-14
专利申请人:
["BENANTI TRAVIS","HESSELL EDWARD T"]
分类号:
["C09K5/04","C10M171/00"]
发明/设计人:
BENANTI, TRAVIS ， HESSELL, EDWARD T.
权利要求: 1. A working fluid for a heat transfer device comprising:i) a hydrofluorocarbon refrigerant comprising difluoromethane (R-32) andii) a polyol ester lubricant composition having a kinematic viscosity at 40° C. of from 32 to 100 cSt and comprising a mixture of C5-10 alkylcarboxy neopentyl polyol esters, said neopentyl polyol esters comprising a mixture of C5-10 alkylcarboxy esters of pentaerythritol, di-pentaerythritol, tri-pentaerythritol and oligomers comprising 4 or more pentaerythritol monomers,wherein at least 10 wt % of all neopentyl polyol esters are esters of oligomers containing 4 or more neopentyl polyol monomer units, andwherein 75 mole % or more of all the C5-10 alkylcarboxy esters of pentaerythritol, di-pentaerythritol, tri-pentaerythritol and oligomers comprising 4 or more pentaerythritol monomers are linear or branched C5 alkylcarboxy esters, and 15-40% of all the C5 alkylcarboxy esters are branched.2. The working fluid according to claim 1 wherein the polyol ester lubricant composition further comprises C5-10 alkylcarboxy esters of neopentyl glycol and/or C5-10 alkylcarboxy esters of trimethylol propane wherein at least 10 wt % of all neopentyl polyol esters are esters of oligomers containing 4 or more neopentyl polyol monomer units, and 50 mole % or more of all the C5-10 alkylcarboxy neopentyl polyol esters are linear or branched C5 alkylcarboxy esters, and 15-40% of all the C5 alkylcarboxy esters are branched.3. The working fluid according to claim 1 wherein the polyol ester lubricant composition comprises:a) from about 30 to about 85 wt % C5-10 alkylcarboxy esters of pentaerythritol,b) from about 1 to about 20 wt % C5-10 alkylcarboxy esters of di-pentaerythritol,c) from about 1 to about 10 wt % C5-10 alkylcarboxy esters of tri-pentaerythritol, andd) from about 10 to about 45 wt % C5-10 alkylcarboxy esters of pentaerythritol oligomers of 4 or more pentaerythritol monomer groupswherein the wt % is based on all neopentyl polyol esters in the lubricant.4. The working fluid according to claim 3 wherein the polyol ester lubricant composition comprises:a) from about 30 to about 55 wt % C5-10 alkylcarboxy esters of pentaerythritol,b) from about 1 to about 20 wt % C5-10 alkylcarboxy esters of di-pentaerythritol,c) from about 1 to about 10 wt % C5-10 alkylcarboxy esters of tri pentaerythritol, andd) from about 25 to about 45 wt % C5-10 alkylcarboxy esters of pentaerythritol oligomers of 4 or more pentaerythritol monomer groups,wherein the wt % is based on all neopentyl polyol esters in the lubricant.5. The working fluid according to claim 3 wherein the polyol ester lubricant composition comprises:(I) from about 50 to about 95% by weight, based on all neopentyl polyol esters in the lubricant composition, a mixture consisting ofa) from about 30 to about 55 wt % C5-10 alkylcarboxy esters of pentaerythritol,b) from about 1 to about 20 wt % C5-10 alkylcarboxy esters of di-pentaerythritol,c) from about 1 to about 10 wt % C5-10 alkylcarboxy esters of tri pentaerythritol, andd) from about 25 to about 45 wt % C5-10 alkylcarboxy esters of pentaerythritol oligomers of 4 or more pentaerythritol monomer groups,wherein the wt % is based on the weight of all esters of pentaerythritol, di-pentaerythritol, tri-pentaerythritol and oligomers comprising 4 or more pentaerythritol monomers,and(II) from about 5 to about 50% by weight, based on all neopentyl polyol esters in the lubricant composition, C5-10 alkylcarboxy esters of neopentyl glycol and/or C5-10 alkylcarboxy esters of trimethylol propane,wherein 50 mole % or more of all the C5-10 alkylcarboxy neopentyl polyol esters are linear or branched C5 alkylcarboxy esters, and 15-40% of all the C5 alkylcarboxy esters are branched.6. The working fluid according to claim 5 wherein the polyol ester lubricant composition comprises(I) from about 60 to about 90% by weight, based on all neopentyl polyol esters in the lubricant composition, of the mixture consisting of a), b), c), and d), and(II) from about 10 to about 40% by weight, based on all neopentyl polyol esters in the lubricant composition, C5-10 alkylcarboxy esters of neopentyl glycol and/or C5-10 alkylcarboxy esters of trimethylol propane.7. The working fluid according to claim 5 wherein from 25 to 60 mol % of all the C5-10 alkylcarboxy neopentyl polyol esters are branched.8. The working fluid according to claim 3 wherein from 25 to 60 mol % of all the C5-10 alkylcarboxy neopentyl polyol esters are branched.9. The working fluid according to claim 1 wherein the polyol ester lubricant has a kinematic viscosity at 40° C. of from 46 to 100 cSt.10. The working fluid according to claim 1 wherein the polyol ester lubricant has a kinematic viscosity at 40° C. of from 68 to 100 cSt.11. The working fluid according to claim 1 wherein the hydrofluorocarbon refrigerant comprises R-32 and less than 15% by weight of the refrigerant is other than R-32 and is selected from other HFC refrigerants, CO2, ammonia and hydrocarbon refrigerants.12. The working fluid according to claim 11 wherein the hydrofluorocarbon refrigerant comprises R-32 and less than 10% by weight of the refrigerant is other than R-32.13. The working fluid according to claim 12 wherein the hydrofluorocarbon refrigerant consists essentially of R-32.14. The working fluid according to claim 1 further comprising in addition to components i) and ii), one or more of a mineral oil, poly-α-olefin, alkylbenzenes, carboxylic acid ester other than the neopentyl polyol ester of component ii), polyether, polyvinyl ether, perfluoropolyether, phosphoric acid ester or mixture thereof.15. The working fluid according to claim 1 further comprising one or more antioxidant, extreme-pressure additive, antiwear additive, friction reducing additive, defoaming agent, profoaming agent, metal deactivator, acid scavenger or mixture thereof.