JPH07278583A - Freezer oil composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition good in compatibility with HFC series cooling media, excellent in water adsorbability, having a larger specific gravity than those of the cooling media, not causing the dissolution of the liquid cooling media in the oil composition even on the long period stoppage of a compressor, and enabling the good lubrication of various sliding parts even on their start-up by adding a prescribed amount of a hard alkylbenzene oil to a specific fluorinated hydrocarbon oil. CONSTITUTION:This composition comprises (A) 99.9-50.0wt.% of a fluorinated hydrocarbon oil of the formula (X is O; R is CF2CH2H, CF2CHFCH3; R is CnH2n+1) and (B) and (B) 0.1-50.0wt.% of a hard alkyl benzene. Further, 90.0-20.0wt.% of the component A, 10.0-80. wt.% of the component B, and/or (C) 0.1-2.0wt.% of tricresylphosphite are preferably used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention uses refrigerants 1, 1, 1, 2
-A refrigerating machine oil composition that is compatible with this refrigerant when made into an HFC system such as tetrafluoroethane (hereinafter referred to as R134a).

[0002]

2. Description of the Related Art Refrigerators, vending machines, and compressors for showcases have conventionally used a large amount of dichlorodifluoromethane (hereinafter referred to as R12) as a refrigerant. This R12
Is subject to CFC regulations due to the problem of ozone layer depletion. Then, as an alternative refrigerant of this R12, R134a
The HFC-based refrigerant represented by No. 1 is studied for refrigerators (see, for example, Japanese Patent Application Laid-Open No. 1-271491).

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
134a has poor compatibility with refrigerating machine oils such as currently used mineral oils and alkylbenzene oils, leading to deterioration of oil return to the compressor, suction of separated refrigerant at the time of start-up, and poor lubrication of the compressor. There was a problem.

Therefore, the present inventors have examined a polyol ester oil as a refrigerating machine oil compatible with the refrigerant R134a. However, when this polyol ester oil is used in a compressor, there is a problem in that the sliding member is corroded by the fatty acid generated by decomposition by heat and wear is caused. Further, there is a problem of impairing the durability of the compressor, such that the abrasion powder adversely affects the organic material for insulation such as the magnet wire of the electric element of the compressor.

Further, there is a problem that the polyol ester oil has poor hydrolysis stability and causes hydrolysis to generate sludge such as metal soap.

Further, since the polyol ester oil is lighter in physical properties than the refrigerant, the liquid refrigerant having a high liquid separation temperature lays in the lower layer when the compressor is stopped for a long period of time, and the liquid refrigerant, not the oil, is started at the time of start-up at each sliding portion. However, there is a problem in that lubrication failure is caused by being supplied to the.

Therefore, the present inventors have decided to use HF such as R134a.
After investigating and studying other oils that have good compatibility with C-based refrigerants, as a result of repeated research, we selected fluorine oil and mixed a predetermined amount of hard alkylbenzene oil with this fluorine oil or added a specified amount of a specific additive. By doing so, the compatibility with HFC-based refrigerant is excellent, the water adsorption is excellent, and since the specific gravity is heavier than the refrigerant, the liquid refrigerant does not lie in the oil even when the compressor is stopped for a long time, and at the time of startup. However, they have invented a refrigerating machine oil that can provide good lubrication of each sliding part.

The present invention solves the above problems.
By using fluorine oil as a refrigerating machine oil, it has good compatibility with HFC-based refrigerants and excellent water adsorption properties, and because it has a higher specific gravity than the refrigerant, it constantly retains oil at the bottom of the compressor, improving the lubrication characteristics. The purpose of the present invention is to provide a machine oil composition.

[0009]

According to the present invention, a refrigerating machine oil composition having compatibility with an HFC type refrigerant such as 1,1,1,2-tetrafluoroethane is provided.
The refrigerating machine oil composition is 99.9 to 50.0% by weight, and the fluorine oil represented by the following general formula is 0.1 to 50.0% by weight.
It is a composition that is mixed with the above hard alkylbenzene.

[0010]

[Chemical 4]

According to the structure of claim 2, 1, 1,
A refrigerating machine oil composition that is compatible with an HFC-based refrigerant such as 1,2-tetrafluoroethane, wherein the refrigerating machine oil composition is 99.9 to 99.0% by weight of a fluorine oil represented by the following general formula. , 0.1 to 1.0% by weight of tricresyl phosphate (TCP).

[0012]

[Chemical 5]

Further, according to the structure of claim 3, 1, 1,
A refrigerating machine oil composition that is compatible with an HFC-based refrigerant such as 1,2-tetrafluoroethane, the refrigerating machine oil composition being 90.0 to 20.0% by weight of a fluorine oil represented by the following general formula. The composition is a mixture of 10.0 to 80.0% by weight of hard alkylbenzene and 0.1 to 2.0% by weight of tricresyl phosphate (TCP).

[0014]

[Chemical 6]

[0015]

The present invention is constructed as described above,
The fluorine oil, which is the base oil, has good compatibility with HFC-based refrigerants, excellent water adsorption, and has a higher specific gravity than the refrigerant, so liquid refrigerant does not lie in the oil even when the compressor is stopped for a long time. Thus, it is possible to provide refrigerating machine oil that can perform good lubrication on each sliding portion even at the time of startup.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in the drawings.

FIG. 1 is a vertical sectional view of a rotary compressor. FIG. 2 is a sectional view of the rotary compressor of FIG. 1 taken along line AA. 1 and 2, 1 is a closed container,
In this container, the electric element 2 is housed on the upper side, and the rotary compression element 3 driven by the electric element is housed on the lower side. The electric element 2 includes a stator 5 having a winding 4 insulated by an organic material and a rotor 6 provided inside the stator 5.
It consists of and. The rotary compression element 3 is a cylinder 7,
A roller 10 that rotates along the inner wall of the cylinder 7 by the eccentric portion 9 of the rotating shaft 8 and a spring 11 that is pressed against the peripheral surface of the roller 7 and divides the cylinder 7 into a suction side and a discharge side. And a lower bearing 14 that seals the opening of the cylinder 7 and that pivotally supports the rotating shaft 8.

The upper bearing 13 is provided with a discharge hole 15 which communicates with the discharge side of the cylinder 7. Further, a discharge valve 16 that opens and closes the discharge hole 15 and a discharge muffler 17 that covers the discharge valve are attached to the upper bearing 13.

The rollers 10 and the vanes 12 are each made of an iron-based material such as steel or casting.

At the bottom of the closed container 1, 90.0-2
0.0% by weight of a fluorine oil represented by the following general formula and 1
Refrigerating machine oil 18 composed by mixing with 0.0 to 80.0% by weight of hard alkylbenzene is enclosed.

[0021]

[Chemical 7]

Further, as described in claim 2, 0.1 to 1.0% by weight of tricresyl phosphate (TCP) is added to the above-mentioned fluorine oil as needed.

Further, as described in claim 3, the above-mentioned three kinds of substances can be mixed in the following compositions, if necessary.
That is, 90.0 to 20.0% by weight of fluorine oil represented by the following general formula, 10.0 to 80.0% by weight of hard alkylbenzene, and 0.1 to 2.0% by weight of tricresylphosphine. The composition is mixed with fate (TCP).

Fluorine oil is limited to the range of 90.0 to 20.0% by weight. If it is less than 20.0% by weight, there is a possibility that oil may not be rehydrated.
This is because there is a problem that sludge is generated when the content is more than the weight percent.

The hard alkylbenzene oil is 10.
It is limited to the range of 0 to 80.0% by weight.

If it is less than 10.0% by weight, there is a problem that sludge is generated, and if it is more than 80% by weight, there is a problem that oil cannot be returned.

Further, TCP is limited to the range of 0.1 to 2.0% by weight.

If it is less than 0.1% by weight, there is a problem that lubricity is insufficient, and if it is more than 2.0% by weight, there is a problem that stability of refrigerating machine oil is impaired.

Further, the phosphoric acid triester contained in the fluorine oil is tricresyl phosphate or tri-3.
-Butylphenyl phosphate and the like.

The oil 18 lubricates the sliding surface between the vane 12 and the roller 10 which is the sliding member of the rotary compression element 3.

The refrigerant that flows into the cylinder 7 of the rotary compression element 3 and is compressed by the cooperation of the roller 10 and the vane 12 is R134a which is compatible with the oil 18 of the mixed oil whose base oil is fluorine oil. Has been formed.

Reference numeral 19 is a suction pipe attached to the closed container 1 to guide the refrigerant to the suction side of the cylinder 7. Reference numeral 20 is attached to the upper wall of the closed container 1 and is compressed by the rotary compression element 3 via the electric element 2. A discharge pipe for discharging the refrigerant to the outside of the closed container 1.

In the refrigerating machine oil composition used in the rotary compressor thus constructed, the refrigerant R134a flowing from the suction pipe 19 to the suction side in the cylinder 7 is the roller 10
Is compressed by the cooperation of the vane 12 with the vane 12 and is discharged through the discharge hole 15 into the discharge muffler 17 by opening the discharge valve 16.
The refrigerant in the discharge muffler passes through the electric element 2 and the discharge pipe 2
It is discharged from 0 to the outside of the closed container 1. And oil 18
Is supplied to the sliding surfaces of sliding members such as the rollers 10 and the vanes 12 of the rotary compression element 3 to perform lubrication. Further, the refrigerant compressed in the cylinder 7 is prevented from leaking to the low pressure side.

The appropriate amount of phosphoric acid triester contained in the fluorinated oil is determined, and if it is less than 0.1% by weight, the effect of suppressing the thermal decomposition of the fluorinated oil is small.
In the above, the corrosive wear and the organic material for insulating the winding 4 of the electric element 2 are adversely affected. Examples 1 to 8 and Comparative Examples 1 to 5 Example 1: 100 wt% Fluorine oil which is a base oil represented by the following general formula, to which 1.0 wt% of tricresyl phosphate (TCP) is added. .

Example 2 A base oil was prepared by mixing 20% by weight of hard alkylbenzene with 80% by weight of a fluorine oil represented by the following general formula.

Example 3: 80% by weight of a fluorine oil represented by the following general formula was mixed with 20% by weight of a hard alkylbenzene to prepare a base oil, and 1.0% by weight of tricresylphosphate was added to the base oil. Fate (TCP) added.

Example 4: 100% by weight A fluorine oil as a base oil represented by the following general formula, to which 0.1% by weight of tricresyl phosphate (TCP) was added.

Example 5: A base oil was prepared by mixing 5% by weight of a hard alkylbenzene with 95% by weight of a fluorine oil represented by the following general formula.

Example 6 50% by weight of a fluorine oil represented by the following general formula and 50% by weight of a hard alkylbenzene were mixed to prepare a base oil.

Example 7: 90 wt% Fluorine oil represented by the following general formula was mixed with 10 wt% of hard alkyl benzene to form a base oil, and then 0.1 wt% of tricresyl phosphate (TCP). ) Is added.

Example 8: 20% by weight 20% by weight of fluorine oil represented by the following general formula was mixed with 80% by weight of hard alkylben to form a base oil, and 2% by weight of tricresyl phosphate (TCP) was added. What was added.

Comparative Example 1: 100% by weight One using only the fluorine oil represented by the following general formula.

Comparative Example 2: Only 100% by weight of mineral oil was used.

Comparative Example 3: 100% by weight of mineral oil as a base oil to which 1.0% by weight of tricresyl phosphate (TCP) was added.

COMPARATIVE EXAMPLE 4 Only 100% by weight of polyale ester oil was used.

Comparative Example 5: 100% by weight of polyaile ester oil to which 1.0% by weight of tricresyl phosphate (TCP) was added.

[0047]

[Chemical 8]

Here, the performance was evaluated with the Amsler type abrasion tester of the method shown in FIG. 3, and the results are shown in Table 1.

[0049]

[Table 1]

Reference numeral 21 is a fixed piece corresponding to a vane, and the tip of this fixed piece is formed by a curved surface having a radius of 4.7 mm.
It receives a load L of kg. Reference numeral 22 denotes a rotating piece corresponding to a roller. This rotating piece has a diameter of 45 mm, and is an oil 23 of a mixed oil (Examples 1 to 8 and Comparative Examples 1 to 5) using fluorine oil as a base oil at a pressure contact portion with the fixed piece 21. Is supplied at a rate of 400 rpm and is rotated at a rate of 400 rpm for 20 hours.

As a result, the wear condition represented by the wear width of the fixed piece and the outer dimension of the rotary piece was within the allowable range in all Examples and Comparative Examples, but the sludge amount in the oil after the test was compared. Example 1 is 14.7 mg / 400, Comparative Example 4 is 30.2 m
g / 400, which exceeds the allowable amount,
It can be understood that in the case of ~ 8, the amount is suppressed to 10.0 mg / 400 or less. In particular, in Example 3, excellent results were obtained in both the wear condition and the sludge amount.

The reason for this is that the fluorine oil, which is the base oil, improves the compatibility with the HFC refrigerant and improves the water adsorption, or the addition of hard alkylbenzene to the fluorine oil, which is the base oil, is safe. This is due to the improved wear resistance and the improved wear resistance of TCP.

In addition, since the specific gravity of the fluorine oil is heavier than that of the refrigerant such as HFC, the liquid refrigerant does not lie in the oil even when the compressor is stopped for a long time, and the good lubrication of each sliding portion is achieved even when the compressor is started. It is possible to provide refrigerating machine oil. That is, since the specific gravity of the fluorine oil is heavier than that of the refrigerant such as HFC, the oil in the closed container 1 is separated into two layers in the order of the fluorine oil rich layer and the HFC refrigerant rich layer from the bottom, and the lower layer serving as the suction portion for lubrication is Fluorine oil is stored, so there is no bad lubrication.

However, if the hard alkylbenzene is mixed in an amount of more than 20% by weight, the above-mentioned two-layer separation is likely to occur, so it is desirable to keep it at 20% by weight or less.

Further, it can be seen from Table 1 that the sliding surface between the fixed piece 21 and the rotary piece 22 is excellent in wear resistance when lubricated with fluorine oil containing tricresyl phosphate, which is the reason for this. Is the thermal decomposition of the fluorocarbon oil due to the sliding friction heat on the sliding surface between the rotating piece 22 and the fixed piece 21 to accelerate the deterioration of the conventional oil contained in the tricresyl phosphate or to corrode the metal. This is considered to be because the impurities such as diesters and monoesters are contained in a certain amount and are suppressed, and corrosion is prevented.

[0056]

As described above, according to the present invention, the fluorine oil, which is the base oil, has good compatibility with the HFC-based refrigerant and excellent water adsorption property, and the specific gravity is heavier than the refrigerant. It is possible to provide refrigerating machine oil in which the liquid refrigerant does not lie in the oil even when stopped and the sliding parts can be satisfactorily lubricated even at the start.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a rotary compressor showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the rotary compressor of the present invention.

FIG. 3 is a plan view of an Amsler type tester.

[Explanation of symbols]

 1 Airtight container 3 Rotating compression element 10 Roller 12 Vane 18 Oil

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location C10N 40:30 (72) Inventor Yasuki Takahashi 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Within Yo Denki Co., Ltd.

Claims (3)

[Claims] 1. A refrigerating machine oil composition compatible with an HFC-based refrigerant such as 1,1,1,2-tetrafluoroethane, wherein the refrigerating machine oil composition comprises 99.9 to 50.0% by weight. A refrigerating machine oil composition comprising a mixture of fluorine oil represented by the following general formula and 0.1 to 50.0% by weight of hard alkylbenzene. [Chemical 1] 2. A refrigerating machine oil composition which is compatible with an HFC-based refrigerant such as 1,1,1,2-tetrafluoroethane, wherein the refrigerating machine oil composition comprises 99.9 to 99.0% by weight. A refrigerating machine oil composition comprising a mixture of fluorine oil represented by the following general formula and 0.1 to 1.0% by weight of tricresyl phosphate (TCP). [Chemical 2] 3. A refrigerating machine oil composition compatible with an HFC-based refrigerant such as 1,1,1,2-tetrafluoroethane, wherein the refrigerating machine oil composition comprises 90.0 to 20.0% by weight. Fluorine oil represented by the following general formula and 10.0 to 80.0
A refrigerating machine oil composition comprising a mixture of wt% hard alkylbenzene and 0.1 to 2.0 wt% of tricresyl phosphate (TCP). [Chemical 3]