JPS59105091A - Refrigerator oil composition - Google Patents

Abstract

PURPOSE:To provide a lubricating oil composition containing a defoamer which prevents foaming when the composition is used at a low viscosity as refrigerator oil, prepared by adding trifluoropropylmethylpolysiloxane to a base oil consisting of a specified synthetic oil. CONSTITUTION:The lubricating oil composition is prepared by adding 0.1- 30ppm trifluoropropylmethylpolysiloxane to a base synthetic oil consisting of paraffinic, nephthenic or mixed mineral oil and olefin and having a viscosity of 3-15cSt at 40 deg.C. Dimethylpolysiloxane having a viscosity of 1X10<3>-1X10<4>cSt has so far been used as defoamer for refrigerator oil, but as the viscosity of the refrigerator oil is reduced, it becomes highly soluble in the oil and loses its foaming preventive power. The trifluoropropylmethylpolysiloxane shows an excellent foaming preventive effect in a state in which the siloxane molecules are incorporated into the refrigerator oil, as foams disappear through destruction of a part of intermolecular force of a hydrocarbon which constitutes the refrigerator oil.

Description

[Detailed description of the invention] Unexploded [9J reciprocating refrigeration compressor using Freon as refrigerant, i
SAMURAI VC As a refrigerating machine oil for household refrigerators and air conditioners,
When a low viscosity oil is used, an antifoaming agent that prevents the oil from foaming.

Yu JL for refrigerating machine oil, general pink black U diful blade Romethane (
Fluon-12), Monocl:IO Difluor. methane(
Freon-22) Freon refrigerants, represented by A and F7, have a lower temperature, and the higher their power, the weaker their dissolving power becomes. As the temperature decreases, it becomes easier to dissolve the fluorocarbon refrigerant, and even in operation 2, the oil is constantly in contact with the fluorocarbon refrigerant, so the fluorocarbon refrigerant is dissolved in the oil.

When the refrigerator starts up after sleeping, the cold Freon in the refrigerator oil turns into a gaff due to mechanical agitation and temperature rise, and the oil surface (forms violently). This can cause seizure of the metal parts, and in some cases may make abnormal noises or cause the refrigerator to become inoperable.Furthermore, the foaming of oil while the refrigerator is operating is a lubricating surface, which is one of the purposes for which refrigerator oil is used. If left in a lubricated state, it will not function normally and cause metal parts to wear out.
In reciprocating refrigeration compressors, foaming of refrigeration oil interferes with normal operation of the IE.

In recent years, reciprocating refrigeration compressors, especially household refrigerators, are
Low viscosity refrigeration oil is being used for this purpose. Conventionally, dimethylborinoxane having a viscosity of 1×10 3 to 1×10′ cstO at 25° C. has been used as an antifoaming agent for refrigerating machine oil. When the viscosity of the refrigerating machine oil is lowered, its solubility increases, so dimethylborinoxane of the above viscosity dissolves in the oil, and the anti-foaming effect is lost. The anti-foaming function is effective when Nlogilin molecules are mixed in Reishin 4 Iku oil. In other words, destroy some of the hydrocarbon intermolecular forces that make up refrigerating machine oil and eliminate bubbles.

A detailed explanation of the experimental example will be given below. JIS K25
The experiment was conducted using an apparatus according to the No. 18 lubricant foaming test method. The oil temperature was 124° C., and the amount of air blown into the oil was 94 to 99 m17 m1n.

Example Two types of naphthenic mineral oils with different viscosities were prepared, and 5, 10, and 20 ppm of dimethylpolynorocane with different viscosities were blended into the oils, and the foaming property was measured. (1st
Table) Example 1 and 5 ppm of trifluorobrobyl methylvorinoloxin were blended into low viscosity naphthenic mineral oil, and the foaming property was measured. (Table 2) Table 1 Foaming property No. 2 of dimethylpolysiloxane formulation
Table 2. Experimental results on foaming wood containing triflopropyl methylborinoxane. This shows that the lower the viscosity of the dimethylpolynoloxane, the less the effect. When the amount of dimethylpolynorocyan is increased, a precipitate is formed in the oil, which causes clogging of the capillary of the refrigerator.

The inventor of this invention completed the invention after confirming that adding a small amount of low viscosity nitrifluoropropylmethylpolysiloxane to the refrigerating machine oil was effective in preventing foaming of the oil surface.

It should be noted that there is no hindrance to further adding lubricating oil additives, particularly oxidation stabilizers, extreme pressure agents, rust preventives, etc. to the refrigerating machine oil composition of the present invention.

Claims (1)

[Claims] Synthetic oils such as paraffinic, naphthenic, mixed mineral oils, and melefinic oils have a viscosity of 3 to 15 cst at 40°C, and trifluoroprobyl methylborinoxane is blended in an amount of 30 pprn. Characterized by Shi Ling Fro (Iku Yu Il composition).