JPH02180986A - 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 OH group, and two or more of them are not simultaneously H; X<1> is H, a hydrocarbon group substd. by at least one OH group, 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 of 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 1] The present invention provides 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. However, 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,
Paraffinic mineral oil cannot be used.

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

Regarding (a), for example, Du pant's Re5ea
rchDisclosure(174830ct, 19
78). Regarding (b), for example, U
, S. 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. The refrigerating machine oil in (7') and (4) is, for example, 40°C.
When the kinematic viscosity at is 100 cst, the high critical temperature (
(see notes in Table 1) are as shown in Table 1, and the compatibility cannot be said to be sufficient.

Table 1 Conventional polyether oil and high temperature critical temperature (ladder high temperature critical temperature: Oil and R-134a are mixed at a weight ratio of 15:85 and sealed. As the temperature is increased, cloudiness or two-layer separation begins. The temperature 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 made extensive efforts, and as a result, they replaced all or part of the ends of polyether oil with an organic compound having at least one hydroxyl group. It was discovered that esterification with carboxylic acid improves compatibility with R-134a, and the present invention was completed.

That is, the present invention provides: (1) Or hydrogen, R", R3, R' may be the same or different. (However, two or more selected from R2H", R' will not be hydrogen at the same time.) XI is hydrogen, at least one A hydrocarbon group substituted with a hydroxyl group or a residue of a monohydroxy compound excluding the hydroxyl group. (However, XI and R2 do not become hydrogen at the same time.) 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.

Q, m, and n are the kinematic viscosity of the above compounds (■ to ■) of 10 to 300.
cst (40°C), which may be the same or different.] This relates to a tetrafluoroethane-based refrigerator composition comprising at least one polyether selected from the following and tetrafluoroethane. be.

XI in one shot ■ is hydrogen, at least 1 g
A hydrocarbon group substituted with a hydroxyl group or a residue of a monohydroxy compound from which the hydroxyl group has been removed. The residues of the monohydroxy compound excluding the hydroxyl group include methyl group,
Preferred are alkyl groups such as ethyl group, propyl group, butyl group, 2-ethylhexyl group, and nonyl group, and aryl groups such as phenyl group.

As X2 in one release (2), a residue or group from which the hydroxyl group of a dihydroxy compound such as an ethylene glycol residue or a propylene glycol residue has been removed is preferable, and as X3 in one release (2), a glycerin residue or a trimethylolpropane residue is preferable. Preferred are residues from which the hydroxyl group of a trihydroxy compound such as a group has been removed.

R1 in one release ■ to ■ is an alkylene group such as an ethylene group, a propylene group, a butylene group, a tetramethylene group, etc., and these may be used alone or together in a random or block form. When doing so, it is preferable to have a propylene group as the main component.-Release■~
R' in (2) may be the same or different.

-R'', R3, and R' in the injections ■ to ■ are at least 1
A hydrocarbon group or hydrogen substituted with hydroxyl groups, which may be the same or different. Specifically, it is a hydroxyalkyl group such as a hydroxymethyl group, a hydroxyethyl group, or a hydroxybutyl group. however,
xl and R2 cannot become hydrogen at the same time. Also, R”,
Two or more selected from R'' and R' cannot become hydrogen at the same time.

Usually, when synthesizing compounds represented by -injection ■, ■, ■, the corresponding initiators are υtl, respectively.
The number of IJ11 active hydrogen groups is 1.
It is 2.3.

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.
When trying to obtain a compound in the range of st (40 °C) to 200 cst (40 °C), the numbers of ρ, m, n, i.e.,
The number of moles of alkylene oxide added is undesirable because it becomes too small and the lubricating performance deteriorates.

In order to sufficiently achieve functions such as friction, wear and seizure prevention in the sliding parts of compressors etc. as refrigerating machine oil, the compounds represented by the above-mentioned -Release ■ to ■ have a kinematic viscosity of 10 to 300 cst ( 40°C), preferably 12
~200 cst (4(1'c)) is desirable, and the molecular weight at -release ■~■ or 2.m
, n are preferably selected to provide such a viscosity range. The values of β, m, and n are approximately 3 to 60,
Preferably it is 6 to 30, and may be the same or different.

The weight ratio of the compounds represented by the above-mentioned -Release ■ to ■ and R134a is l/99 to 99/1, 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 the general formulas (■) to (■) of the present invention and conventionally used naphthenic mineral oils, paraffinic mineral oils,
It 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 possible.

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] 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.

[Effects of the Invention] The composition of the present invention has high compatibility between tetrafluoroethane and polyether oil, and reduces friction in sliding parts of compressors and the like.
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 hydroxyl group or hydrogen, and R^2, R^3, and R^4 may be the same or different. (However, R^2, R^3,
Two or more selected from R^4 cannot become hydrogen at the same time. ) X^1 is hydrogen, a hydrocarbon group substituted with at least one hydroxyl group, 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.