JPS62146996A - Refrigerator oil composition - Google Patents

Abstract

PURPOSE:To obtain the titled compsn. having excellent extreme pressure properties and useful for use as an extreme-pressure additive in a refrigeration compressor which uses a flon gas as a refrigerant, by blending a mineral oil and/or a base oil comprised of a synthetic oil with a particular compd. CONSTITUTION:A mineral oil (A) (e.g., naphthene mineral oil) and/or a base oil comprised of a synthetic oil (e.g., alpha-olefin) is blended with 5vol% or less of at least one compd. selected from among a perfluoroalkyl polyether of the formula (wherein n is 10-60) and its derivative having a carboxyl group, a hydroxyl group, etc., and, if necessary, other lubricating additives.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention primarily relates to the lubricity of a rotary refrigeration compressor using Freon as a refrigerant.

Recently, the type of refrigeration compressor has changed from a reciprocating type to a rotary type, a screw type, and a scroll type, and has also become tighter. For this reason, the clearances of the metal sliding parts are becoming increasingly finer, the refrigerant compression pressure is increasing, and the requirements regarding the lubricity of the refrigerating machine oil are becoming more severe.

Mineral oils and synthetic oils, especially alkylbenzenes, α-olefins, glycols, and esters, have some advantages and disadvantages, but they are insufficient in terms of lubricity for the rotary refrigeration compressors mentioned above, and cannot be improved with additives. I have no choice but to. Currently, sulfur compounds and phosphorus compounds are generally used as extreme pressure additives. Both sulfur and phosphorus compounds are mild as extreme pressure agents and do not fully satisfy lubricity. Sulfur compounds tend to produce corrosive substances when they deteriorate, and phosphorus compounds can cause hydrolysis, so they are not the best extreme pressure additives for refrigeration oil. Furthermore, if a metal compound with a large extreme pressure effect is used, it may cause accidents such as capillary tube choke in the refrigeration system, so it cannot be used.

The inventor of the present invention considered whether a fluorine compound could be used as an extreme pressure agent for refrigerating machine oil. Commonly commercially available fluorine compounds include fluorinated fluoropolyether + CF2-CF2-0 + n4 fluorinated ethylene oligomer (-CF2-CF2 +).Extreme pressure properties were measured by adding fluorinated fluoride, but the extreme pressure effect was not found. Although the tetrafluoroethylene oligomer exhibited excellent extreme pressure properties, it is a solid fine powder with poor flexibility and can cause capillary tube choke in refrigeration systems.

Perfluoroalkyl polyether is generally CFB
It has a structure where n=10 to 60.

Examples will be specifically described below.

Examples Naphthene mineral oil (VG82), α-olefin (VG60
) Single substance and α-olefin (VG60) perfluoroalkyl polyether carboxylic acid CF8C
The seizure load of the refrigerating machine oil containing 0.25 VO (1% F8) was measured using a Falex tester.The measurement was carried out at room temperature at 800 rpm.
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Fig.) Results of Farex seizing load test Pressing load (kli) The seizing load of α-olefin (VG60) alone was 580 kQ, and the addition of a small amount was very effective. Furthermore, this compound is a fluorine compound similar to fluorocarbon refrigerant, and when used in a refrigeration system, there is no problem with reactivity with refrigeration oil, refrigerant, and other organic substances.

Here, the inventors discovered that adding a small amount of perfluoroalkyl polyether and its derivatives to the refrigerating machine oil base oil had an effect on extreme pressure properties, and completed the present invention.

There is no hindrance to further adding lubricating oil additives to this.

Patent Applicant Nishi-Nippon Trading Co., Ltd. Procedural Amendment Document Showa Chizuki Sono 7 Director General of the Japan Patent Office Tono Giden L. 2 &ah%# Nao Mukan M 3 Relationship with the case of the person making the amendment Patent request 1, 5 Target of correction (9-sided rib diagram - sacrifice 'J# rt
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mouth and mouth Pressing load (kg)

Claims (1)

[Claims] Mineral oil, synthetic oil, or a mixture of both oils is used as the base oil, and at least 5% by volume of perfluoroalkyl polyether and at least one of its derivatives having a carboxyl group, hydroxyl group, etc. is blended based on the total amount. Refrigerating machine oil composition.