Henkel Corporation

Cognis Corporation

National Distillers and Chemical Corporation

Cognis IP Management Gmbh

Nicholas E Schnur

Eugene R Zehler

Bruce J Beimesch

Clarence J Hughes, Jr

A method of improving performance of refrigerant systems such as refrigerators and air conditioners that utilize a refrigerant working fluid. The working fluid consists essentially of a heat transfer fluid and a lubricant that is miscible and is otherwise compatible with the heat transfer fluid at all operating temperatures of the refrigerant system. The method is directed particularly to chlorine-free fluoro-group organic fluids and more particularly to hydrofluorocarbon heat transfer fluids. The preferred lubricants comprise polyol ester basestocks and compounded polyol esters that are highly miscible with such hydrofluorocarbon heat transfer fluids.

Method of improving performance of refrigerant systems

A high quality lubricant for hermetically sealed domestic air conditioner and refrigerator compressors, especially those using chlorine free hydrofluorocarbon refrigerant working fluids, is provided by mixed esters of hindered polyols, most desirably pentaerythritol, with a mixture of carboxylic acids including at least some iso-pentanoic acid along with either or both of iso-nonanoic acid and dibasic acids such as adipic.

Polyol ester lubricants for hermetically sealed refrigerating compressors

An ester blend, including an ester having neopentylglycol and a source of 2-ethylhexanoic acid as its reactive components and an ester having pentaerythritol and a source of 2-ethylhexanoic acid as its reactive components, is especially effective as a lubricant for chlorine-free fluorocarbon refrigerant heat transfer fluids, particularly Refrigerant 134a (1,1,1,2-tetrafluoroethane).

Blended polyol ester lubricants for refrigerant heat transfer fluids

A high quality lubricant for compressors operated during at least part of their compression cycle at temperatures above normal human comfort temperatures, such as most automotive air conditioners, especially those using chlorine free hydro-fluorocarbon refrigerant working fluids, is provided by mixed esters of hindered polyols, most desirably pentaerythritol, with a mixture of carboxylic acids including at least some iso-pentanoic acid along with one or more of iso-nonanoic acid, isooctanoic acid, and dibasic acids such as adipic. When the mixture includes about 7% adipic and amounts of branched C and C monobasic acids in a ratio of at least 0.75:1.00, the esters formed have excellent solubility for paraffinic and naphthenic mineral oils and are therefore especially well suited for lubricating vehicle air conditioners formerly containing chlorine containing heat transfer fluids and mineral oil lubricants.

Polyol ester lubricants, especially those compatible with mineral oils, for refrigerating compressors operating at high temperatures

A high quality lubricant for compressors operated during at least part of their compression cycle at temperatures above and below normal human comfort temperatures, especially those using chlorine free hydrofluorocarbon refrigerant working fluids, is provided by mixed esters of hindered polyols, most desirably pentaerythritol, with a mixture of carboxylic acids including iso-pentanoic acid, trimethylhexanoic acid, and preferably n-pentanoic acid.

Polyol ester lubricants for refrigerator compressors operating at high temperatures

A high quality lubricant for heavy duty service air conditioner and refrigerator compressors, especially those using chlorine free hydrofluorocarbon refrigerant working fluids, is provided by mixed esters of hindered polyols, most desirably di-pentaerythritol, usually mixed with some pentaerythritol, with a mixture of carboxylic acids including at least some of each of iso-pentanoic acid and iso-nonanoic acid.

Polyol ester lubricants for refrigerating compressors operating at high temperature

A high quality lubricant for hermetically sealed domestic air conditioner and refrigerator compressors, especially those using chlorine free hydrofluorocarbon refrigerant working fluids, is provided by mixed esters of hindered polyols, most desirably pentaerythritol, with a mixture of carboxylic acids including at least some isopentanoic acid along with either or both of iso-nonanoic acid and dibasic acids such as adipic.

A two-step process comprising as a first step draining a refrigerant heat transfer fluid made of molecules containing at least one chlorine atom per molecule and mineral oil lubricant dissolved therein from an unflushable compressor and associated piping in a vehicle air conditioner, thereby leaving a mineral oil residue. The second step comprises replacing the refrigerant heat transfer fluid in all parts of the vehicle air conditioner designed to contain such fluid with a replacement heat transfer fluid. The replacement fluid consists essentially of 1,1,1,2-tetrafluorethane and a composition of matter suitable for serving as the lubricant or lubricant base stock. The composition of matter is capable of forming a soluble clear solution with a mineral oil residue in a weight ratio of mineral oil to composition of at least 25:100 and forming a single phase with 1,1,1,2-tetrafluoroethane between &minus;55&deg; C. and &plus;71&deg; C. The composition of matter is a liquid having a viscosity between 45 and 220 centistokes at 40&deg; C. and consisting essentially of a mixture of polyol esters derived primarily from pentaerythritol and an acid mixture comprising isopentanoic acid, branched acids of eight and/or nine carbon atoms and adipic acid.

Polyol ester lubricants for refrigerating compressors operating at high

The electrical resistivity of hindered polyol ester lubricants can be raised to very high levels by treating the lubricants with activated alumina, preferably after the acid values of the lubricants treated have already been reduced to low levels by conventional refining with alkali or other acid scavengers.

Increasing the electrical resistivity of ester lubricants, especially

From not more than three blending stocks, it is possible to prepare a wide variety of mixtures of esters of hindered polyhydric alcohols that are especially valuable lubricants for chlorine-free fluorocarbon refrigerant heat transfer fluids, particularly Refrigerant 134a (1,1,1,2-tetrafluoroethane).

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Cincinnati, OH, United States of America

Nicholas E Schnur