JPH02180987A - Tetrafluoroethane refrigerator composition - Google Patents

Abstract

PURPOSE:To prepare a refrigerator compsn. wherein two ingredients are highly compatible with each other and which sufficiently functions to prevent the wear, friction and seizure of sliding parts of a compressor, etc., by compounding a specific polyether with tetrafluoroethane. CONSTITUTION:A polyether selected from the group consisting of compds. of formulae I, II and III [wherein R<1> is alkylene; R<2>, R<3> and R<4> are each H or a hydrocarbon group substd. by at least one halogen, and two or more of them are not simultaneously H; X<1> is H, a hydrocarbon group substd. by at least one halogen, or a residue of a monohydroxyl compd. from which OH group is removed, and X<1> and R<2> are not simultaneously H; X<2> is a residue to a dihydroxyl compd. from which two hydroxyl groups are removed; and l, m and n are each such a positive integer that the kinematic viscosities of the compds. of formulae I, II and III are each 10-300cSt at 40 deg.C] and tetrafluoroethane are compounded to give a refrigerator compsn. The resulting compsn., in which said two ingredients are highly compatible with each other, sufficiently functions to prevent the wear, friction and seizure of sliding parts of a compressor, etc.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is directed to a refrigerant, tetrafluoroethane, preferably 1,1,1,2-tetrafluoroethane (R-134
For a), from -20℃ or lower, +
The present invention relates to a composition for a refrigerator consisting of polyether and tetrafluoroethane that are compatible with each other in any ratio within a temperature range of 40° C. or higher.

[Conventional technology] In the refrigeration cycle of refrigerators and car air conditioners, R
-12 (dichlorodifluoromethane) has been used as a good refrigerant. Shigashi R-12 can destroy the ozone layer in the stratosphere and have a negative impact on biological systems, so alternatives are being considered. R-134a is considered to be the most promising substitute for R-12;
Naphthenic mineral oil and paraffinic mineral oil, which are common refrigeration oils for R-12, are not compatible with R-134a. Therefore, naphthenic mineral oil and paraffinic mineral oil cannot be used as refrigeration oil for R-134a. Can not.

Polyether oils having the structures shown in Table 1 are known as substances that are relatively compatible with R-134a.

Regarding (a), for example, Dupont's Re5erc
hDisclosure (174830ct, 197g
)It is described in. Regarding (b), for example, U,
Pat. No. 4.755°316.

[Problems to be Solved by the Invention] However, the polyethers shown in Table 1 do not have sufficient compatibility with R-134a. In other words, in order to demonstrate lubricity, which is the most important role of refrigerating machine oil, R-134a
It must be compatible with R-134a and circulate within the system together with R-134a. <7'), (For example, when the refrigerating machine oil in () has a kinematic viscosity of 100 cst at 40°C, the high temperature critical temperature (see notes in Table 1) is as shown in Table 1. What is sufficient compatibility? It's no big deal.

Table 1 Conventional polyether oil, high critical temperature (*) high critical temperature oil, and R-134a were mixed at a weight ratio of 15:85 and sealed. As the temperature is increased, the temperature at which turbidity or two-layer separation begins is called the high temperature critical temperature. The better the compatibility, the higher the high-temperature critical temperature.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present inventors have made extensive efforts, and as a result, the present inventors have discovered an organic polyether oil in which all or part of the ends of the polyether oil are substituted with at least one halogen atom. It was discovered that esterification with carboxylic acid improves compatibility with R-134a, and the present invention was completed.

That is, the present invention has the following formula: [wherein R1 is an alkylene group, R2, Rs, R- is a hydrocarbon group or hydrogen substituted with at least 1 g of halogen atoms, R2, R', R' may be the same or different (however, two or more selected from R2H" and R' may not be hydrogen at the same time). xl is hydrogen, a hydrocarbon group substituted with at least one halogen atom Or the residue of a monohydroxy compound from which the hydroxyl group has been removed. (However, X'gR'' does not become hydrogen at the same time.) xl 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. ] β, m, fi are the kinematic viscosity of the above compounds
0cst (40"C), which may be the same or different," relates to a tetrafluoroethane-based refrigerator composition comprising at least one polyether selected from the following and tetrafluoroethane. be.

x' in one release (3) is hydrogen, a hydrocarbon group substituted with at least one halogen atom, or a residue of a monohydroxy compound excluding the hydroxyl group. The residue of the monohydroxy compound excluding the hydroxyl group is preferably an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a 2-ethylhexyl group, a nonyl group, or an aryl group such as a phenyl group.

x2 in one-release ■ is preferably a residue from which the hydroxyl group of a dihydroxy compound such as an ethylene glycol residue or a propylene glycol residue has been removed;
3 is preferably a residue from which the hydroxyl group of a trihydroxy compound has been removed, such as a glycerin residue or a trimethylolpropane residue.

R'eL in one release Φ ~ In this case, it is preferable that the main component is a propylene group. −Release ■～
R1 in (2) may be the same or different.

-R'', R'', and R' in the injection Φ~■ are at least 1
a hydrocarbon group or hydrogen substituted with halogen atoms, such as fluorine, chlorine, bromine or a combination thereof;
These may be the same or different, and specifically are halogenated alkyl groups such as trifluoromethyl group, trichloromethyl group, difluoromethyl group, monofluoromethyl group, and trifluoroethyl group. However, XI and R2
cannot be hydrogen at the same time, and R'', R'', R'
Two or more selected from cannot become hydrogen at the same time.

Usually, when synthesizing the compounds represented by -injection (1), (2), and (2), the number of active hydrogen groups in the corresponding initiators is 1 and 2.3, respectively.

Using an initiator with the number of active hydrogen groups of 4 or more, the kinematic viscosity is 12c, which is the general kinematic viscosity of refrigeration oil for car air conditioners and refrigerators.
st (40°C) to 200cst (40°C), the number of β, m, and n, that is, the number of added moles of alkylene oxide, is small (too much,
This is not preferable because the lubrication performance deteriorates.

In order to fully achieve the functions of friction, wear and seizure prevention in the sliding parts of compressors, etc. as refrigerating machine oil, the compounds represented by the above-mentioned -releases 1 to 2 have a kinematic viscosity of lO to 300cst. (40°C), preferably 1
It is desirable to have a molecular weight of 2 to 200 cst (40°C), and the molecular weight or Q, m, n
It is preferable to select a value such that the viscosity falls within this range.12. The values of m and n are approximately 3 to 60, preferably 6 to 30, and may be the same or different.

The weight ratio of the compounds represented by -Release ■ to ■ and R134a is 1/99 to 99/l, preferably 5/95 to 60.
/40. R134a may contain a small amount of 1,1,2,2-tetrafluoroethane (R134). -Release Compounds ① to ① can be used alone or as a mixture thereof.

The composition of the present invention is particularly effective in refrigeration cycle applications for freezing, refrigeration, and air conditioning in the low to high temperature fields, but can also be used in various other heat recovery technologies such as Rankine cycles. be.

The composition of the present invention has excellent thermal stability and does not require a stabilizer under normal usage conditions, but when it is necessary to improve thermal stability due to harsh usage conditions, dimethyl phosphite , phosphite compounds such as diisopropyl phosphite and diphenyl phosphite, phosphine sulfide compounds such as triphenoxyphosphine sulfide and trimethylphosphine sulfide, and other stabilizers such as glycidyl ethers may be added in small amounts.
In addition, the compounds represented by ■ to ■ of the present invention and conventionally used naphthenic mineral oils, paraffinic mineral oils,
Can be mixed with alkylbenzene-based synthetic oil, poly-α-olefin-based synthetic oil, perfluoropolyether oil which is a fluorinated lubricating oil, fluorine-containing silicone oil, or polyether oil other than the polyether oil of the present invention. It is.

Additionally, various additives such as phenol-based or amine-based antioxidants, sulfur- or phosphorus-based extreme pressure additives, silicone-based antifoaming agents, or metal deactivators such as benzotriazole may be added to the composition of the present invention. It may be further added.

[Example J Examples 1 to 5, Comparative Examples 1 to 5 Structure of oil used in Examples 1 to 5 and Comparative Examples 1 to 5, R-
Table 2 shows the results of compatibility with 134a, hygroscopicity, and kinematic viscosity at 40°C.

[Effect of the invention 1] The composition of the present invention has high compatibility between tetrafluoroethane and polyether oil (friction in sliding parts of compressors, etc.).
Functions such as wear and seizure prevention can be fully demonstrated.

Claims (1)

[Claims] 1. The following general formula [1] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [2] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [3] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [In the formula, R^1 is an alkylene group, R^2, R^3, R^
4 is a hydrocarbon group substituted with at least one halogen atom or hydrogen, and R^2, R^3, and R^4 may be the same or different. (However, R^2, R^3, R
Two or more selected from ^4 cannot become hydrogen at the same time. ) X^1 is hydrogen, a hydrocarbon group substituted with at least one halogen atom, or a residue of a monohydroxy compound excluding the hydroxyl group. (However, X^1 and R^2 do not become hydrogen at the same time.) X^2 is the residue of a dihydroxy compound from which the hydroxyl group has been removed. X^3 is the residue of the trihydroxy compound from which the hydroxyl group has been removed. ] l, m, n are the kinematic viscosity of the above compounds [1] to [3] of 10
It is a positive number that is ~300cst (40°C), and may be the same or different. ] A tetrafluoroethane-based refrigerator composition comprising at least one polyether selected from the following and tetrafluoroethane.