JPH1046174A - Refrigerator oil composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigerator oil compsn. which is suitable to be used with a chlorofluorocarbon substitute and can be used with a conventional refrigerant in a similar way to a refrigerator oil compsn. contg. a silicone-based foam stabilizer by compounding a base oil with an org. fluorine compd. or a fluorinated siloxane compd. SOLUTION: A base oil selected from among synthetic or natural lubricating oils. such as a mineral oil (paraffininc or naphthenic), a POE (polyol ester) oil, a PAG (polyalkylene glycol) oil, and a carbonate oil, is componded with 50-5,000ppm org. fluorine compd. which acts as a foam stabilizer and is a polymer having perfluoroalkyl and/or perfluoroalkylene groups and at least one kind of functional group selected from among ester. alcohol, epoxy, and ketone bonds in the molecule or is compounded with 20-5,000 ppm fluorinated siloxane compd. having fluoroalkyl and/or fluoroalkylene groups in the molecule.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating machine oil composition, and more particularly to a refrigerating machine oil composition which can reduce the operating noise of a compressor, has no problem of blockage of a capillary tube, and has good lubricity. .

[0002]

2. Description of the Related Art A refrigerating machine oil composition is circulated in a compressor such as an electric refrigerator or an air conditioner to lubricate sliding parts together with a refrigerant. This refrigerating machine oil composition is obtained by adding an antiwear agent, an antioxidant, a metal deactivator, a stabilizer (acid scavenger) and the like to a base oil composed of a lubricating oil. It is well known that the operating noise of a compressor can be reduced by appropriately bubbling the internal base oil. Conventionally, in order to adjust the foaming properties of the base oil, a substance called a foam stabilizer or an antifoaming agent (hereinafter referred to as a defoamer) is used. , Generically referred to as foam stabilizers). Silicone compounds such as dimethylsiloxane are used as the foam stabilizer.

On the other hand, Freon-12 and Freon-22, which are conventionally widely used as refrigerants for electric refrigerators and air conditioners, etc.
Due to environmental problems such as depletion of the ozone layer, HFC-based fluorocarbons (for example, HFC-134a) are being replaced with alternative chlorofluorocarbons. PAG (polyalkylene glycol) and P are suitable base oils for these alternative CFCs.
Various synthetic oils such as OE (polyol ester) are used. For example, JP-A-2-102296 discloses that
Polyoxyalkylene glycol having a specific kinematic viscosity, and 1,1, containing polyoxypropylene glycol and at least one of phenol-based, amine-based, phosphorus-based, benzotriazole-based antioxidant, and a phosphorus-based antiwear agent A lubricating oil for a refrigerator using a 1,2-tetrafluoroethane refrigerant is described.
Japanese Patent No. 158693 describes a refrigerating machine oil composition for a fluorinated alkane-based refrigerant containing at least one of dibasic acid ester, fluorinated product, and polyhydric alcohol ester silicon fluoride and a polyglycol compound.

[0004]

However, in electric refrigerators and air conditioners, there has been a problem that the capillary tube is closed and the cooling capacity is reduced. As such a plugging substance, the above-mentioned foam stabilizer component has been detected in addition to a process auxiliary material, an oil degraded product, and the like. Especially,
Conventionally used silicone foam stabilizers are poorly compatible with the alternative fluorocarbons that must be used in the future, and it is fully expected that poor cooling due to blockage of the capillary tube will easily occur. In addition, it is an essential requirement that the operating noise of the compressor be quiet for refrigeration and air conditioning equipment used in ordinary households, especially for home refrigerators and room air conditioners,
In recent years, the demand has been increasing. However, regarding the foam stabilizer added for reducing the operation noise, it is difficult to use the silicon foam stabilizer in a refrigeration / air-conditioning apparatus using an alternative Freon for the above-described reason.

The present invention has been made in view of the above circumstances, and is suitable for use as a substitute for chlorofluorocarbons. An object is to provide a machine oil composition.

[0006]

The above object is achieved by the refrigerating machine oil composition according to the present invention, wherein a base oil is mixed with a fluoride of an organic fluorine compound or a siloxane compound.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the refrigerating machine oil composition according to the present invention will be described in detail. The base oil of the refrigerating machine oil composition of the present invention is not particularly limited, and mineral oils (paraffins, naphthenes), POEs (polyol ester oils), PAGs (polyalkylene glycol oils) conventionally used as this type of base oils ), Carbonate oil, ether oil, fluorine oil, alkylbenzene (hard type, soft type) and PAO (poly-
Typical examples thereof include synthetic or natural lubricating oils such as (α-olefin).

The organic fluorine compound and siloxane of the present invention
Compound fluoride acts as a foam stabilizer
It is. Preferred organic fluorine compounds include their molecules
A perfluoroalkyl group and / or perfluorinated
Having a low alkylene group and an ester bond in the molecular structure
From alcohol, epoxy and ketone bonds
Having at least one type of functional group selected from the group consisting of
It is a polymer. Specifically, RR as a monomer unit
₁ , R-COO-R₁ , R₁ -COO-R, R-O-R
₁ , R-CO-R₁ , RR₁ -OH, RR_Two And R
_Two -R _Three (Where R is C₁ ~ C₄₀Of the fluoroalkyl
Group, fluoroalkylene group, perfluoroalkyl group or
Represents a perfluoroalkylene group, and R ′ represents C₁ ~ C
₄₀Represents an alkyl group or an alkylene group of_Two Is C₁ 
~ C₄₀The epoxy oxygen with an alkyl or alkylene group of
A group having at least one or more R_Three Is fluoro
Alkyl group, fluoroalkylene group, perfluoroal
Epoxy oxygen with a kill group or a perfluoroalkylene group
Represents a group having at least one or more groups. ) Has the structure
Polymer.

In the above, particularly preferred organic fluorine compounds are shown below.

[0010]

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The degree of polymerization of these organic fluorine compounds is not particularly limited, and may be dimers or trimers. Also, depending on the combination with the base oil, it may not completely dissolve in the base oil, but even if it does not dissolve, the viscosity at -40 ° C is 6,000 [cS
t] or a viscosity at -20 ° C of 2,200 [cS
t] or less, there is no problem in use. If the viscosity is higher than the above-mentioned value, the separated foam stabilizer tends to stay and easily block the capillary tube, which is not preferable.
Since these organic fluorine compounds contain a large amount of fluorine atoms in their skeletons, their affinity with the alternative fluorocarbons, which are also fluorine-based compounds, is much higher than that of silicon-based foam stabilizers.

The refrigerating machine oil composition of the present invention is characterized in that the above-mentioned organic fluorine compound is added to the above-mentioned base oil in an amount of 50 to 5000 p.
pm compounded and completed. Here, when the amount of the organic fluorine compound is less than 50 ppm, the foam regulating action is not exhibited, while
If the amount exceeds ppm, the amount of foam generated is too large and the lubricity may be reduced, which is not preferable.

In the refrigerator oil composition of the present invention, a siloxane compound fluoride may be used as a foam stabilizer. The preferred fluoride of the siloxane compound is a siloxane compound having a fluoroalkyl group and / or a fluoroalkylene group in its molecular structure. Particularly preferred fluoride of the siloxane compound is represented by the following general formula [A]
It is a compound represented by these.

[0014]

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[A] In the formula, R ₄ represents a C ₁ -C ₄₀ alkyl or alkylene group, or a C ₁ -C ₄₀ fluoroalkyl, fluoroalkylene, perfluoroalkyl or perfluoroalkylene group. , R ₅ is C
An alkyl or alkylene group of ₁ to ₄₀ , or C ₁
To a C ₄₀ fluoroalkyl group, a fluoroalkylene group,
R ₆ represents a C _{1 to} C ₄₀ fluoroalkyl group, a fluoroalkylene group, a perfluoroalkyl group or a perfluoroalkylene group; Also, m is 0 to 100
And n represents an integer of 1 to 100. The fluorides of these siloxane compounds have both a foam regulating action and a lubricating action.

The siloxane compound fluoride is preferably blended in an amount of 20 to 5000 ppm based on the base oil. Here, the fluoride of the siloxane compound is 20
When the amount is less than ppm, the foam-regulating action is not exhibited.
If the amount exceeds m, the amount of foam generated is too large, and the lubricity may be reduced, which is not preferable.

The refrigerating machine oil composition of the present invention contains conventionally known additives such as an antiwear agent, an antioxidant, a metal deactivator and a stabilizer (acid scavenger) as long as the effects of the present invention are not impaired. Agent) etc. may be added.

[0018]

The following examples and comparative examples illustrate the refrigerating machine oil composition of the present invention in more detail. However, it goes without saying that the present invention is not limited to this. In the following description, among the organic fluorine compounds used as foam stabilizers, an organic fluorine compound having a base oil solubility is an F-based / soluble type, which is insoluble in the base oil, but is insoluble in the above-mentioned viscosity range. Is referred to as an F-type, low-viscosity, non-dissolving type, and an organic fluorine compound insoluble in base oil and having a viscosity higher than the above viscosity range is referred to as an F-type, high-viscosity, non-dissolving type.

(Examples 01 to 03) Polyol ester
For oils, use F-type, soluble-type organic fluorine compounds [F (CF
_Two) _mCH_Two CH_Two OOCCH = CH_Two 50 ppm
(Example 01), 2,000 ppm (Example 02) and
5,000 ppm (Example 03) added, mixed and refrigerator
An oil composition was prepared.

(Examples 04 to 06) An F type, low viscosity, insoluble type organic fluorine compound [F (CF ₂ ) _m CH ₂ CH ₂ OOC (CF ₂ ) _n F;
m = n = 2] at 50 ppm (Example 04), 2,000
ppm (Example 05) and 5,000 ppm (Example 0)
6) Added and mixed to prepare a refrigerator oil composition.

(Examples 07 to 09) Fluoride of a siloxane compound shown below was added to polyol ester oil in an amount of 20 p.
pm (Example 07), 2,000 ppm (Example 08)
And 5,000 ppm (Example 09) were added and mixed to prepare a refrigerator oil composition.

[0022]

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(Comparative Examples 01 to 04) Polyol ester oil alone (that is, without a foam stabilizer) was used as Comparative Example 01. Further, an F-type, high-viscosity, non-dissolvable type organic fluorine compound [(C ₄ F ₉ CH ₂ CH ₂ OO) is added to the polyol ester oil.
CCHCH ₂ ) _m ] at 50 ppm (Comparative Example 02), 2,
Refrigerating machine oil compositions were prepared by adding and mixing 000 ppm (Comparative Example 03) and 5,000 ppm (Comparative Example 04).

COMPARATIVE EXAMPLES 05-07 Dimethylsiloxane, a silicone-based foam stabilizer, was added to polyol ester oil in an amount of 5%.
0 ppm (Comparative Example 05), 2,000 ppm (Comparative Example 0)
6) and 5,000 ppm (Comparative Example 07) were added and mixed to prepare a refrigerator oil composition.

(Comparative Examples 08-09) Polyol ester
For oils, use F-type, soluble-type organic fluorine compounds [F (CF
_Two) _mCH_Two CH_Two OOCCH = CH_Two 45 ppm
(Comparative Example 08) and 5,500 ppm (Comparative Example 09)
The mixture was added and mixed to prepare a refrigerating machine oil composition.

(Comparative Examples 10 to 11) 15 ppm of the siloxane compound fluoride used in Examples 07 to 09 (Comparative Example 10) and 5,500 p
pm (Comparative Example 11) was added and mixed to prepare a refrigerator oil composition.

Reference Examples 01 and 02 Further, for comparison, refrigeration oil composition (Reference Example 01) was prepared by adding and mixing 10 ppm of dimethylsiloxane, a silicone-based foam stabilizer, to naphthenic mineral oil. And Naphthenic mineral oil alone (that is, no foam stabilizer) was used as Reference Example 02.

The refrigerating machine oil compositions prepared in the above Examples, Comparative Examples and Reference Examples were evaluated as follows. (1) Solubility The solubility of the foam stabilizers used in Examples 01 to 09 and Comparative Examples 02 and 05 was evaluated by the following method. Anti-oil: The base oil was placed in a glass container, various foam stabilizers were weighed and added, and then the state when cooled to -40 ° C was observed. Refrigerant: In accordance with JISK-2211.4.12, the refrigerating machine oil composition and the refrigerant were collected in a test tube, and the state when cooled to −40 ° C. was observed. Oil to refrigerant: In accordance with JISK-2211.4.12, the refrigerator oil composition and the refrigerant were collected in a test tube, and the state when cooled to -40 ° C was observed. Table 1 shows the results.

[0029]

[Table 1]

In Table 1, "x" indicates that turbidity was observed, that is, insoluble, and "o" indicates that the film was transparent, that is, dissolved.

(2) Oil return property The refrigerating machine oil composition prepared in each of Examples 01 to 09 has the following properties.
A 00 hour compressor test was performed to measure the amount of the foam stabilizer before and after the test. Table 2 shows the results.

[0032]

[Table 2]

The amount of the foam stabilizer after the test is desirably 99% or more before the test, and it is understood that the refrigerator oil composition of the present invention has excellent oil return properties.

(3) Foamability The refrigerator oil compositions prepared in Examples 01 to 09, Comparative Examples 08 to 11 and Reference Example 01, polyol ester oil alone (Comparative Example 01) and naphthenic mineral oil alone (Reference Example 02)
For the refrigerant HF according to JIS K-2518.
C-134a (however, Reference Examples 01 and 02 are CFC-1
The foaming property was evaluated by measuring the foaming amount when blowing 2). Table 3 shows the results.

[0035]

[Table 3]

The foamability of the refrigerating machine oil is practically 60 to 7
It is desirable that the amount is 100 ml or more at 0 ° C., and Table 3 shows that the refrigerating machine oil composition of the present invention has excellent foamability.

(4) Stability Regarding the refrigerating machine oil compositions prepared in Examples 01 to 09,
Based on JIS K-2211.4.9, the chemical stability when HFC-134a was used as a refrigerant was evaluated. Table 4 shows the results.

[0038]

[Table 4]

Table 4 shows that the refrigerating machine oil composition of the present invention is excellent in hue, total acid value and stability against metals, and is extremely chemically stable.

(5) Sound Absorbing Sound The refrigerating machine oil compositions prepared in Examples 01 to 09, Comparative Examples 08, Comparative Examples 10, and Reference Example 01 and naphthenic mineral oil alone (Reference Example 02) produced noise during compressor operation. (1 kH _Z) was measured to evaluate the sound deadening qualities by the amount of change operating noise. Table 5 shows the results.

[0041]

[Table 5]

The refrigerator compressor generated sound of (1kH _Z)
In practice, it is desirable that the fluctuation amount is 5 dB or less, preferably 2 dB or less. Table 5 shows that the refrigerating machine oil composition of the present invention has good sound deadening properties.

(6) Capillary flow rate retention The refrigerating machine oil compositions prepared in Examples 01 to 09, Comparative Examples 02 to 07 and Reference Example 01 were subjected to a compressor test for 2,000 hours, and the capillary flow rate retention after the test was performed. Was measured to evaluate the difficulty of blocking the capillary tube. Table 6 shows the results.

[0044]

[Table 6]

It is desirable that the refrigerating machine oil used in the refrigerator of the electric refrigerator has a capillary flow rate retention of 90% or more in practical use. From Table 6, the refrigerating machine oil composition of the present invention has an excellent capillary flow rate retention. It shows that it shows.

(7) Lubricity Examples 01 to 03, Examples 07 to 09 and Comparative Example 09,
For the refrigerator oil composition prepared in Comparative Example 11, 2,0
The compressor test was performed for 00 hours, and the amount of wear on the sliding portion was measured to evaluate the lubricity. Table 7 shows the results.

[0047]

[Table 7]

When the abrasion loss was equal to or less than that of the refrigerating machine oil containing no foam stabilizer (Comparative Example 01), it was judged as acceptable (indicated by “○” in the table). As is clear from Table 7, the refrigerator oil composition of the present invention does not show a decrease in lubricity due to the foam stabilizer. Further, in the above (3) evaluation of foaming property, Comparative Example 09 showing the highest foaming amount at all measurement temperatures.
And the refrigerating machine oil composition of Comparative Example 11 is inferior in lubricity, and therefore, there is a certain correlation between the foaming amount and the lubricating property, and the refrigerating machine oil composition of the present invention satisfies both of them. You can see that.

From the above Examples and Comparative Examples, the refrigerating machine oil composition of the present invention shows that the compounded fluoride of the organic fluorine compound and the siloxane compound shows high solubility in both the CFC substitute and the base oil. In the evaluation items (1) and (2), excellent evaluation results equivalent to or higher than the case of using the conventional silicone-based foam stabilizer were shown, and it was confirmed that they were preferable as refrigerating machine oils for CFC substitutes and conventional refrigerants.

[0050]

As described above, according to the present invention,
It is suitable as a substitute for CFCs, and can be used with conventional refrigerants as well as a refrigerating machine oil composition containing a silicon-based foam stabilizer, can reduce compressor operating noise of refrigeration equipment, and has no capillary tube blockage. Thus, it is possible to provide a refrigerator oil composition having good lubricity.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C10N 40:30 (72) Inventor Tohru Matsuo 3-4 Kojimachi, Chiyoda-ku, Tokyo Nippon San Oil Co., Ltd. In company

Claims (1)

[Claims] 1. A refrigerating machine oil composition comprising a base oil mixed with a fluoride of an organic fluorine compound or a siloxane compound.