JPH02286780A - Composition for compression refrigerating machine - Google Patents

Abstract

PURPOSE:To prevent the wear, friction, and seizure of sliding parts of a compressor by compounding a polyalkylene glycol and/or alkylarom. synthetic oil having a specified viscosity and tetrafluoromonochloroethane. CONSTITUTION:The title composition comprises a polyalkylene glycol in which pref. at least 60wt.% of alkylene oxides is propylene oxide and which has at least one OH group and a viscosity at 40 deg.C of 10-300cSt and/or alkylarom. synthetic oil comprising mono or dicyclic alkylarom. compd. pref. having one or two 6-40C linear or branched alkyl groups and a viscosity at 40 deg.C of 10-300cSt (A); tetrafluoromonochloroethane (B) in a wt. ratio of A to B of (1:99)-(99:1) pref. (5:95)-(60:40); and if necessary a stabilizer, antioxidant, extereme- pressure additive, antifoamer, metal deactivator, etc.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a composition for a compression refrigerator that prevents wear, friction, and seizure in the sliding parts of a compressor used in a compression refrigerator. .

[Prior Art] Naphthenic mineral oil, paraffinic mineral oil 1, and poly-α-olefin synthetic oil are conventionally known as lubricating oils for fluorocarbon compressors, and these oils reduce wear and friction in compressor sliding parts. It is also used for purposes such as preventing burn-in.

The characteristics required for lubricating oil for fluorocarbon compressors are as follows:
Unlike general lubricating oil, it involves contact with fluorocarbons as a refrigerant, so it must have good stability against refrigerants, excellent solubility with refrigerants, and polymeric materials such as packing materials used as materials. It is required that the material not be dissolved.

Dichlorodifluoromethane (hereinafter referred to as R12) has been conventionally used as a refrigerant and a working medium for heat pumps.
Regarding dichlorotetrafluoroethane (hereinafter referred to as R114), conventionally used mineral oils satisfy the above requirements, but due to the ozone layer depletion of completely halogenated CFCs, Environmental problems have been pointed out, and there is an urgent need to develop a new chilled tofu to replace R114. 1.1 as a new refrigerant to replace R114.
2.2-tetrafluoro-1-chloroethane (hereinafter referred to as R
124) and 1.1.1.2-titrafluoro-2-chloroethane (hereinafter referred to as 124a) are considered to be promising, but when used as a refrigerant, lubrication that meets the above requirements by 2 to 1 is required. Oil becomes essential.

[Problems to be Solved by the Invention] As lubricating oils for R124 and R124a compressors, conventionally known naphthenic mineral oils and paraffinic mineral oils meet the requirements of lubricating oils and R124 and R12
Regarding the solubility of 4a, it has the disadvantage of not exhibiting sufficient solubility.

If the solubility of R124 and R124a and lubricating oil is poor, the lubricating oil carried out by droplets from the compressor will separate from the refrigerant in the condenser, evaporator, dryer, piping, etc., resulting in extremely high viscosity. This results in poor return of oil to the compressor, resulting in a decrease in the amount of oil in the compressor, and further causes problems such as wear, friction, and seizing of the compressor in sliding parts, which is undesirable.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides R124 and R]
, 24a As a result of repeated studies on lubricating oils for compressors, the present inventors have found that polyalkylene glycols containing at least one hydroxyl group (hereinafter simply referred to as glycol oil) and alkyl aromatic synthetic oils are preferable. heading,
The present invention has now been completed.

That is, the present invention provides compounds and compounds that can prevent wear, friction, seizure, etc. in the sliding parts of compressors by using the glycol oil and alkyl aromatic synthetic oil as lubricating oils for R124 and R124a compressors. R1
The present invention relates to a composition for a compression refrigerator consisting of R124a and R124a.

In the present invention, the glycol oil has a viscosity of 10 to 300c in order to sufficiently achieve functions such as friction, wear and seizure prevention in the sliding parts of the compressor.
St (40° C.) is desirable, and the molecular weight of the compound is desirably selected such that the viscosity falls within this range. Examples of the glycol oil are shown below.

■Xl-0-(R’O) 1-R2 You can leave it on.

Xl is hydrogen, an alkyl group, or a residue of a monohydroxy compound from which the hydroxyl group has been removed.

X2 is the residue of a dihydroxy compound from which the hydroxyl group has been removed.

X3 is the residue of the trihydroxy compound from which the hydroxyl group has been removed. ko ■'X'-0-(RIO)l-C-R2 [wherein, R
1 is an alkylene group; R2, R3, 1 and 14 are alkyl groups, acyl groups, or hydrogen; R2, R3, and 4 may be the same or different. (However, at least one selected from R2, R3, and R4 is hydrogen.) 1, m, and n represent the kinematic viscosity of the above compounds ■ to ■ from 1O to 300 cSt (40°C)
are positive numbers, which may be the same or different [wherein, R1 is an alkylene group, R2, R3, and RA are a hydrocarbon group substituted with at least one hydroxyl group, and a hydrocarbon group substituted with at least one halogen atom. Hydrogen group or hydrogen, R2, R3
, R4 may be the same or different. (However, R2,
At least one selected from R3 and R4 is hydrogen. ) 1, m, n are the kinematic viscosity of the above compounds ■' to ■' is 10
It is a positive number of ~300 cSt (40°C), and may be the same or different.

Xl is hydrogen, a hydrocarbon group substituted with at least one halogen atom, or a residue of a monohydroxy compound excluding the hydroxyl group.

X2 is the residue of the dihydroxy compound from which the hydroxyl group has been removed.

X3 is the residue of the trihydroxy compound from which the hydroxyl group has been removed. ] Furthermore, it is desirable that the n:j glycol oil contains 60 wt% or more of propylene oxide in the alkylene oxide.

The alkyl aromatic synthetic oil has a viscosity of lO to 300 cSt in order to sufficiently achieve functions such as friction, wear and seizure prevention in the sliding parts of the compressor.
(40℃), and it is desirable to select a molecular weight of the compound such that the viscosity range is within this range. A monocyclic or bicyclic alkyl aromatic compound containing these compounds is preferred.

Further, the glycol oil and the alkyl aromatic synthetic oil may be mixed in a ratio of 1/99 to 99/1, and especially when stability of the lubricating oil is required, the alkyl aromatic synthetic oil may be mixed. A composition with a large mixing ratio of oil is preferable, whereas a composition with a large mixing ratio of glycol oil is preferable if, on the other hand, it is desired to suppress changes in viscosity due to temperature changes of the lubricating oil. Further, the glycol oil and the alkyl aromatic synthetic oil 11'
The weight ratio of the glycol oil, alkyl aromatic synthetic oil mixture, and tetrafluoromonochloroethane is 1/99 to 99/1, preferably 5795 to 60/4.
[It is 1.

The compound tetrafluoromonochloroethane in the present invention has two types of compounds, R124 and R124a, due to differences in structure, but in the present invention, since their properties are similar, they may be used in combination with jlj, - and R124a. .

The composition of the present invention is effective in applications such as refrigeration cycles for freezing, refrigeration, and air conditioning in low- to high-temperature fields, and heat pump cycles for hot water supply. It can also be used for various heat recovery techniques.

The composition of the present invention has excellent stability and does not require a stabilizer under normal usage conditions, but when it is necessary to improve stability due to harsh usage conditions, tricresicyl phosphate can be used. , butyl dicresyl phosphate, di(n
- Phosphate compounds such as (butyl) cresyl phosphate, phosphite compounds such as dimethylphosphite, diisopropyl phosphite, diphenyl phosphite, or thiophosphite compounds, or triphenoxyphosphine sulfide, trinotylphosphine sulfide, etc. phosphine sulfide compounds,
In addition, a small amount of about 1 part by weight of stabilizers such as glycidyl ethers, phenolic antioxidants, amine antioxidants, etc. may be added to 100 parts by weight of the working medium. Furthermore, it is possible to mix and use the glycol oil of the present invention with conventionally used naphthenic mineral oils, paraffinic mineral oils, poly-α-olefin synthetic oils, and the like.

In addition, the composition of the present invention can be used to treat various types of bridging agents such as phenol-based and amine-based antioxidants, sulfur- and phosphorus-based extreme pressure additives, silicone-based antifoaming agents, and metal deactivators such as benzotriazole. It may be further added to.

Furthermore, the refrigerants R124 and 124a of the present invention are made into a non-azeotropic mixed medium to improve efficiency using the Lorentz effect, and to improve solubility with lubricating oils and polymeric materials. It is also possible to use it in combination with hydrogen, hydrocarbons, etc.

[Example] Glycol oils shown in Tables 1 and 2 below (Example 1 is the one in which xl is an alkyl group and R2 is hydrogen in the above formula (■), Examples 2 and 3 are those in which R2, R
3 is hydrogen. ), alkyl aromatic synthetic oil (
Example 4 used Barrel Freeze 26S manufactured by Matsuzai Oil Co., Ltd., and Example 5 used Barrel Freeze 32S manufactured by Matsuzai Oil Co., Ltd.
Solubility and stability testing with R124 was performed.

Oil and R124 were sealed in a glass ampoule at a weight ratio of 30/70, and the presence or absence of dissolution of the oil and R124 was visually determined based on the presence or absence of an interface between the two liquids. The results are shown in Table 1 together with a comparative example (mineral oil Suniso 4GS manufactured by Nippon Sun Oil Co., Ltd.).

Oil and R124 were sealed at a weight ratio of 50,150 in a 5US316 pressure-resistant container together with typical metals SS41 and Cu, and the temperature was kept constant at 41! The deterioration status of oil, R124 and metal after the test was confirmed by a relative comparison of the degree of deterioration in the combination of conventionally used R114 and Suniso 4GS. . Combined with the results,
Shown in the table.

Table 1-1 Table 1-2 [Effects of the Invention] As is clear from the Examples, the composition for compression refrigerators of the present invention has good solubility and stability. This is an excellent product that can prevent friction, wear, and seizure.

Claims (1)

[Claims] 1. has at least one hydroxyl group, and has 10 to 300
A composition for a compression refrigerator comprising at least one polyalkylene glycol having a viscosity of cSt (40°C) or an alkyl aromatic synthetic oil having a viscosity of 10 to 300 cSt (40°C) and tetrafluoromonochloroethane. 2. The composition for a compression refrigerator according to claim 1, which contains 60 wt% or more of propylene oxide in the alkylene oxide of the polyalkylene glycol. 3. The compression refrigerator according to claim 1, wherein the alkyl aromatic synthetic oil is a monocyclic or bicyclic alkyl aromatic compound containing 1 to 2 linear or branched alkyl groups having 6 to 40 carbon atoms. Composition for use.