Lubricating oil composition for refrigerators

Abstract

Provided is a lubricating oil composition for a refrigerator which uses a base oil including as the main component at least one kind of oxygen-containing compounds selected from polyoxyalkylene glycols, polyvinyl ethers, copolymers of poly(oxy)alkylene glycols or monoethers thereof and polyvinyl ethers, polyol esters, and polycarbonates. The lubricating oil composition for a refrigerator is used for a refrigerator that uses, as a refrigerant, a fluorine-containing organic compound, which is a refrigerant applicable to current car air conditioner systems or the like and has a specific polar structure, and has favorable sealing property, a low coefficient of friction factor in a sliding part, and excellent stability as well as excellent compatibility with the refrigerant.

Description

TECHNICAL FIELD[0001]The present invention relates to a lubricating oil composition for a refrigerator. More specifically, the present invention relates to a lubricating oil composition for a refrigerator using, as a refrigerant, a fluorine-containing organic compound containing a specific polar structure. The refrigerant has a low global warming potential and is applicable to, in particular, current car air conditioner systems or the like. The lubricating oil composition for a refrigerator uses a base oil including a specific oxygen-containing compound as a main component.BACKGROUND ART[0002]In general, a compression refrigerator includes at least a compressor, a condenser, an expansion mechanism (such as an expansion valve), and an evaporator, or further includes a drier, and is structured so that a mixed liquid of a refrigerant and lubricating oil (refrigerator oil) circulates in the closed system. In such compression refrigerator, the temperature in the compressor is generally h...

AI Technical Summary

Benefits of technology

[0012]According to the present invention, there can be provided a lubricating oil composition for a refrigerator using, as a refrigerant, a fluorine-containing organic compound containing a specific polar structure. The refrigerant has a low global warming potential and is applicable to, in particular, current car air conditioner systems or the like. The lubricating oil composition for a refrigerator has favorable sealing property, a low coefficient of friction in a sliding part, and excellent stability as well as excellent compatibility with the refrigerant.

Problems solved by technology

In such compression refrigerator, the temperature in the compressor is generally high, and the temperature in the condenser is generally low, though such general theory is not applicable to a certain kind of such compression refrigerator.

The occurrence of the phase separation during the operation of the refrigerator adversely affects the lifetime or efficiency of the refrigerator to a remarkable extent.

For example, when the phase separation of the refrigerant and the lubricating oil occurs in the compressor portion, a movable part is insufficiently lubricated, with the result that baking or the like occurs to shorten the lifetime of the refrigerator remarkably.

On the other hand, when the phase separation occurs in the evaporator, the lubricating oil having a high viscosity is present, with the result that the efficiency of heat exchange reduces.

However, such compounds each contain chlorine that is responsible for environmental issues, so investigation has been conducted on a chlorine-free alternative refrigerant such as a hydrofluorocarbon (HFC).

The carbon dioxide requires high pressure, and hence cannot be used in the current car air conditioner system.

Images