JP2000017282A - Refrigerator oil composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a refrigerator oil compsn. which is thermally stable, has high electrical insulation properties, low moisture absorption properties, and a high compatibility with a hydrofluorocarbon refrigerant, and exhibits very high abrasion inhibition effects by compounding a phosphorothionate compd. into a refrigerator oil comprising a polyether. SOLUTION: A polyether represented by the formula: R1-[X-OR4]s is used. In the formula, R1 is an s-valent group having an arom. ring; X is a divalent group comprising, on average, q -OR2- groups and r -OR3- groups [wherein R2 is an ethylene group optionally having a methyl or ethyl group; R3 is an ethylene group having a 1-4C alkoxymethyl group; and (q) and r are each 0 or higher provided (q+r)×s is 3-80]; R4 is 1-10C alkyl; and (s) is 1-6. Pref., the phosphorothionate compd. is one represented by the formula: (RO)n(OH)3-nP= S (wherein R is an org. group; and (n) is 1-3) and is compounded in an amt. of 0.05-10 pts.wt. based on 100 pts.wt. polyether.

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 used for a compression type refrigerating machine such as an air conditioner and an electric refrigerator. Specifically, hydrofluorocarbons such as 1,1,1,2-tetrafluoroethane (hereinafter, referred to as HFC-134a), difluoromethane (hereinafter, referred to as HFC-32), and pentafluoroethane (hereinafter, referred to as HFC-125) The present invention relates to a refrigerating machine oil composition containing a polyether having excellent compatibility with a refrigerant (hereinafter, referred to as an HFC-based refrigerant), being thermally and chemically stable, and having excellent wear resistance.

[0002]

2. Description of the Related Art Conventionally, dichlorodifluoromethane (hereinafter referred to as "CFC-12") has been mainly used as a refrigerant for refrigerators for car air conditioners and refrigerators, and chlorodifluoromethane (hereinafter referred to as "HCFC-22") has been mainly used for room air conditioners. HFC-134a, which has been used as a refrigerant for refrigeration equipment, can be substituted for chlorine-containing refrigerants such as CFC-12 and HCFC-22 from the standpoint of protecting the ozone layer.
HFC-based refrigerants such as HFC-32 and HFC-125 have been developed.

[0003] HFC-based refrigerants include CFC-12 and CFC-2.
2 and has almost no compatibility with lubricating oils such as naphthenic mineral oils and alkylbenzenes which have been generally used as a refrigerating machine oil, so that two-layer separation occurs in the operating temperature range of the refrigerating machine. When two-layer separation occurs, oil return deteriorates, lubricating oil adheres to the inner wall of the heat exchanger, resulting in a poor heat exchange rate, poor lubrication, and foaming at start-up. Becomes Therefore, the conventional refrigerating machine oil cannot be used as a refrigerating machine oil under these new refrigerant atmospheres.

As a refrigerating machine oil that can be used together with an HFC-based refrigerant such as HFC-134a, a polyether-based oil (Japanese Patent Publication No. 4-78674, Japanese Patent Application Laid-Open Nos.
-102296, JP-A-3-109492, etc., polyester-based oils (Tokuhei 3-502472, Tokuhyo Hei 3-5)
05602, JP-A-3-88892, JP-A-3-217
494, JP-A-5-25484, JP-A-5-17926
8) and carbonate-based oils (JP-A-3-217)
495, JP-A-4-18490, JP-A-4-6389
3, JP-A-5-32588, JP-A-5-32992, JP-A-5-186784, JP-A-6-87791, etc.).

[0005]

Since these refrigerating machine oils proposed so far have higher polarity than naphthenic mineral oil and alkylbenzene, HFCs such as HFC-134a are used.
The compatibility with the system refrigerant is certainly good. However, the conventional working fluids of CFC-12 / mineral oil system and CFC
-22 / Compared to the mineral oil system, the polarity of both the refrigerant and the refrigerating machine oil is high, and water is easily contained.

[0006] Therefore, these refrigerating machine oils are HFC-
There are disadvantages such as poor thermal stability in the presence of an HFC-based refrigerant such as 134a, and hydrolysis of a polyethylene terephthalate film or the like which is a coil coating material for a compressor motor. In particular, polyester-based oils themselves hydrolyze to form carboxylic acids, which have the problem of corroding metals and causing metal wear. In addition, carbonate-based oils have a problem that non-condensable carbon dioxide is generated by hydrolysis.

Further, since the compressor motor is built in the compressor, good electrical insulation is required. However, a polyether-based lubricating oil which is excellent in that it does not hydrolyze has a conventional volume resistivity. At about 10 ¹¹ Ω / cm, it could not be said that there was good electrical insulation.

On the other hand, polyether oils having low hygroscopicity and good electrical insulation properties are disclosed in JP-A-4-15295.
It has been proposed in JP-A-4-39394, JP-A-4-130188 and JP-A-6-330062. However, this polyether-based oil did not sufficiently satisfy all of the properties of compatibility with the HFC-based refrigerant, low hygroscopicity, high electric insulation, and abrasion suppressing effect.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a heat stable, high electrical insulation, low moisture absorption, HFC
An object of the present invention is to provide a refrigerating machine oil composition which has good compatibility with a refrigerant and has a particularly high effect of suppressing abrasion.

[0010]

The present invention is a refrigerating machine oil composition comprising polyethers represented by the following general formula (1) and phosphorothioates. R ^1- [X-OR ⁴ ] _s (1) wherein R ¹ is an s-valent group having an aromatic nucleus, and X is an average of q -OR ² -and an average of r -OR ^3-. R ² is an ethylene group optionally having a methyl group or an ethyl group, R ³ is an ethylene group having an alkoxymethyl group having 1 to 4 carbon atoms in the alkoxy group, and R ⁴ is a carbon atom Shows the alkyl groups of Formulas 1 to 10. s is an integer of 1 to 6, q is 0 to 6, r is 0.5 or more, and (q + r) × s is a number that is 3 to 80.

In the present invention, R ¹ of the polyether represented by the general formula (1) is an s-valent group having an aromatic nucleus.
s is an integer of 1 to 6, and s is preferably an integer of 1 to 2 from the viewpoint of easy availability of raw materials. Examples of the monovalent group having an aromatic nucleus include an aryl group and an aralkyl group.

An aryl group is a residue obtained by removing one hydrogen atom directly bonded to an aromatic nucleus from an aromatic hydrocarbon, such as a phenyl group, a biphenylyl group or a naphthyl group, or a group having an alkyl group portion. Is mentioned. An aralkyl group is a group in which a hydrogen atom of an alkyl group is substituted with an aryl group. In other words, an aralkyl group is a group in which an aryl group is bonded to one bond of an alkylene group.

As the divalent to hexavalent group having an aromatic nucleus, a residue obtained by removing 1 to 5 hydrogen atoms of an aryl group or an aralkyl group, or bisphenol A, bisphenol F,
Examples thereof include a residue of a bisphenol such as bisphenol S from which a hydroxyl group has been removed.

The hydrogen atom which is removed from the aryl group or the aralkyl group by 1 to 5 as described above is a hydrogen atom directly bonded to an aromatic nucleus, or a hydrogen atom bonded to an alkyl group or an alkylene group directly bonded to an aromatic nucleus. Either or both.

Preferred R ¹ is a monovalent group having an aromatic nucleus, particularly an aryl group, and more preferably a phenyl group or a naphthyl group having an alkyl group.

The alkyl group of the phenyl or naphthyl group having an alkyl group may be linear, branched or cyclic. The following are preferred as the phenyl group or naphthyl group having an alkyl group portion.

Methylphenyl, ethylphenyl, propylphenyl, butylphenyl, pentylphenyl, hexylphenyl, heptylphenyl, octylphenyl, nonylphenyl, decylphenyl, dodecylphenyl, dimethylphenyl , Diethylphenyl group, dipropylphenyl group, dibutylphenyl group, dipentylphenyl group, dihexylphenyl group,
Diheptylphenyl group, dioctylphenyl group, dinonylphenyl group, didecylphenyl group, didodecylphenyl group, methylnaphthyl group, ethylnaphthyl group, dimethylnaphthyl group, diethylnaphthyl group and the like.

The alkylene group of the aralkyl group may be linear, branched or cyclic. The following are preferred as the aralkyl group. Benzyl, phenylethyl, phenylpropyl, phenylbutyl, phenylpentyl, phenylhexyl, phenylheptyl, phenyloctyl, phenylnonyl, phenyldecyl, phenyldodecyl, methylbenzyl, naphthylmethyl Such.

The carbon number of the aryl group and the aralkyl group is preferably 14 or less from the viewpoint of compatibility with the HFC-based refrigerant.
The compatibility with the C-based refrigerant decreases, and phase separation occurs. Preferred aryl groups have 6 to 12 carbon atoms, and preferred aralkyl groups have 7 to 12 carbon atoms.

X in the general formula (1) is an average of q -OR ²
- the average r pieces of -OR ³ - is a divalent group comprising a. The average q is the number of polyethers 1 represented by the general formula (1).
It means the number obtained by dividing the total number of —OR ² — in the molecule by the number of s-valent groups. Similarly, the average r means the number obtained by dividing the total number of —OR ³ — in one molecule of the polyether represented by the general formula (1) by the number of s-valent groups. further,
q and r are 0 or more, and (q + r) × s is a number from 3 to 80.

-OR ² -and -OR ^3-in X are adjacent R ¹ and R ² , R ¹ and R ³ , R ² and R ³ , R ³ and R ⁴ ,
And R ² and R ⁴ are, for example, R ^1- [OR ² -OR ³ -O
R ⁴ ] _s and R ^1- [OR ³ -OR ² -OR ⁴ ] _s are all connected so as to be connected by an ether bond.
Similarly, when two or more —OR ² — in X are adjacent, adjacent R ² and R ² are connected by an ether bond. 2 in X
The same applies to the case where two or more -OR ³ -are adjacent to each other.

R ² in the general formula (1) is an ethylene group optionally having a methyl group or an ethyl group, that is, an ethylene group, an ethylene group having a methyl group, or an ethylene group having an ethyl group. is there. -Of repeating unit
As OR ² —, an oxyethylene group [—OCH ₂ CH
_2- ], an oxypropylene group [-OCH ₂ CH (C
H ₃₎ -], it includes oxy-1,2-butylene group. —OR ² — in one molecule may be one kind selected from an oxyethylene group, an oxypropylene group and an oxy-1,2-butylene group, or may contain two or more kinds selected from these. . Here, the oxy-1,2-butylene group refers to “—OCH ₂ CH (C ₂ H ₅ ) —”, “—
_{OCH (CH 3) CH (CH} 3) - "or" -OCH
₂ C (CH _{3) 2} - means ".

As the repeating unit —OR ² —, those having an essential oxypropylene group are preferable from the viewpoint of viscosity characteristics and volume resistivity. In the case of polyethers, to improve the volume resistivity, an oxyethylene group,
A higher content of the oxy-1,2-butylene group than the oxypropylene group is more effective. However, since the compatibility with the HFC-based refrigerant is reduced, -OR ²
The content of the oxy-1,2-butylene group in the total weight of-is preferably 70% by weight or less.

The oxyethylene group and the oxypropylene group are formed by opening the ring of ethylene oxide and propylene oxide, respectively. An oxy-1,2-butylene group is formed by opening 1,2-butylene oxide, 2,3-butylene oxide or isobutylene oxide. The oxy-1,2-butylene group in one molecule may be one obtained from the same butylene oxide alone or an oxyalkylene group obtained from two or more kinds of butylene oxide.

R ³ in the general formula (1) is an ethylene group having an alkoxymethyl group having 1 to 4 carbon atoms in the alkoxy group, and the repeating unit —OR ³ — is oxy (methoxymethyl) ethylene. Group, oxy (ethoxymethyl) ethylene group, oxy (propoxymethyl) ethylene group, oxy (butoxymethyl) ethylene group, and may be one type selected from these, or two or more types selected from these. . In the case of two or more kinds, the bonds thereof may be block-like or random-like. Where-
When OR ³ — is represented by a general formula, [—OCH ₂ CH (CH ₂ O
_{C n H 2n + 1) -} , n is the integer of 1 to 4].

As the —OR ³ — of the repeating unit, those containing an oxy (methoxymethyl) ethylene group or an oxy (ethoxymethyl) ethylene group are preferable from the viewpoint of compatibility with the HFC-based refrigerant and viscosity characteristics. Further, in order to improve the volume resistivity, it is more effective that the content of the oxy (butoxymethyl) ethylene group is higher than the content of the oxy (methoxymethyl) ethylene group. However, since the compatibility with the HFC-based refrigerant is reduced, the -OR in one molecule is reduced.
The content of the oxy (butoxymethyl) ethylene group in the total weight of ^3- is preferably 70% by weight or less.

Examples of the oxy (alkoxymethyl) ethylene group include those formed by ring-opening alkyl glycidyl ethers such as methyl glycidyl ether, ethyl glycidyl ether, propyl glycidyl ether, and butyl glycidyl ether. The oxy (alkoxymethyl) ethylene group in one molecule may be obtained from the same alkyl glycidyl ether alone, or may be an oxy (alkoxymethyl) ethylene group obtained from two or more alkyl glycidyl ethers. In the case of two or more kinds, the bonds thereof may be block-like or random-like.

In X in the general formula (1), the bond between -OR ² -and -OR ^3- may be block-shaped or random.

R ^{4 in the} general formula (1) is an alkyl group having 1 to 10 carbon atoms. The alkyl group having 1 to 10 carbon atoms may be linear, branched, or cyclic. Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group,
Isopropyl group, butyl group, pentyl group, hexyl group,
Examples include a heptyl group, an octyl group, a nonyl group, a decyl group, a cyclopentyl group, and a cyclohexyl group. HF
From the viewpoint of compatibility with the C-based refrigerant, R ⁴ is preferably an alkyl group having 1 to ⁴ carbon atoms.

In the general formula (1), s is an integer of 1 to 6, and when s is 2 or more, a plurality of Xs in one molecule may be the same or different. q and r are numbers of 0 or more, and (q + r) × s is 3 to 80. q is 0
And the general formula (1) -OR a polyether in a molecule, represented by ² - that does not exist, and r is 0, the general formula (1) in polyether molecule in represented To -OR ^3-
Does not exist. q is preferably from 0 to 6,
r is preferably 0.5 or more.

If the value of (q + r) × s exceeds 80, the object of the present invention cannot be sufficiently achieved from the viewpoint of kinematic viscosity. A preferred value of (q + r) × s is 3 to 40, and a more preferred value of (q + r) × s is 3 to 15. From the viewpoint of solubility, more preferred q is from 0 to 5, and more preferred q is q.
Is 1-4. From the viewpoint of kinematic viscosity, more preferred r is 0.5 to 10, and more preferred r is 1 to 7.

The polyether represented by the general formula (1) used in the present invention can be synthesized by various methods. For example, when the polyether has —OR ² —, the following method may be used.

An alkylene oxide and an alkyl glycidyl ether are added to a compound represented by the general formula R ¹ (OH) _s (wherein R ¹ is an s-valent group having an aromatic nucleus, and s is an integer of 1 to 6). A polyether obtained by the above method is converted into an alcoholate with an alkali, and then reacted with an alkyl monohalide to effect etherification. Examples of the alkyl monohalide include chloride, bromide and iodide of an alkyl group having 1 to 10 carbon atoms.

By simultaneously adding the alkylene oxide and the alkyl glycidyl ether to the compound represented by the above general formula R ¹ (OH) _s , -OR ² -and -OR
A bond having a random OR ³ — bond is obtained, and a bond having a block bond between —OR ² — and —OR ³ — is obtained by separately adding an alkylene oxide and an alkyl glycidyl ether.

100 ° C. of the polyethers in the present invention
Is preferably 1 to 100 cSt, and 2 to 30 cSt.
St is more preferred. The kinematic viscosity at 40 ° C. is 1 to
10,000 cSt is preferable, and 5 to 1000 cSt is more preferable. A particularly preferred kinematic viscosity at 40 ° C. is 5 to 5
00cSt. Further, the two-layer separation temperature at a low temperature with the HFC-based refrigerant is preferably 0 ° C or lower, more preferably -10 ° C or lower.

In the present invention, the polyethers preferably have an acid value of 0.1 mg KOH / g or less and a water content of 200 ppm or less.

The refrigerator oil composition of the present invention contains phosphorothionates. As the phosphorothionate, a compound represented by the general formula (RO) _n (OH) _3-n P = S [R is a monovalent organic group and n is 1, 2, or 3] is preferable. More preferred phosphorothionates are alkyl phosphorothionates and aryl phosphorothionates.

The alkyl phosphorothionates include trimethyl phosphorothionate, triethyl phosphorothionate, tributyl phosphorothionate,
Trioctyl phosphorothionate, tridecyl phosphorothionate, trilauryl phosphorothionate and the like are preferred. As the arylphosphorothionates, triphenylphosphorothionate and the like are preferable.

The phosphorothionates may be used alone or in combination of two or more. The mixing ratio of the phosphorothionates in the refrigerator oil composition of the present invention is as follows:
The amount is preferably 0.05 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the polyether represented by the general formula (1). If the compounding ratio is too small, the abrasion resistance does not improve, and if it is too large, the effect corresponding to the increase in the compounding amount cannot be obtained.

It is preferable to add a phosphate ester to the refrigerator oil composition of the present invention since the abrasion resistance is further improved.

Examples of the phosphoric acid esters include trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tributoxyethyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, and diphenyl orthoxenil. Lephosphate, octyl diphenyl phosphate,
Examples include phenylisopropylphenyl phosphate, diphenylisopropylphenyl phosphate, tris (isopropylphenyl) phosphate, tris (chloroethyl) phosphate, and trisdichloropropylphosphate.

Of these, tricresyl phosphate, phenylisopropylphenyl phosphate, diphenylisopropylphenyl phosphate, and tris (isopropylphenyl) phosphate are preferred.

The above phosphoric esters may be used alone or in combination of two or more.

The mixing ratio of the phosphoric acid ester is preferably 0.1 to 30 parts by weight, more preferably 0.5 to 20 parts by weight, based on 100 parts by weight of the polyether oil. If the compounding ratio is too small, the abrasion resistance does not improve, and if it is too large, the effect corresponding to the increase in the compounding amount cannot be obtained.

Since the effect of suppressing the formation of sludge due to the deterioration of the polyether oil is further improved, it is preferable to incorporate an epoxy compound into the refrigerator oil composition of the present invention.

Epoxy compounds include phenyl glycidyl ether, alkylphenyl glycidyl ether, 1,2-epoxyalkane, vinylcyclohexene dioxide and the like. Among them, 1,2-epoxyalkane and vinylcyclohexene dioxide are preferred.

Examples of the alkyl phenyl glycidyl ether include butyl phenyl glycidyl ether, pentyl phenyl glycidyl ether, hexyl phenyl glycidyl ether, heptyl phenyl glycidyl ether, octyl phenyl glycidyl ether, nonyl phenyl glycidyl ether, and decyl phenyl glycidyl ether.

As the 1,2-epoxyalkane,
2-epoxyhexane, 1,2-epoxyheptane,
Examples thereof include 1,2-epoxyoctane and 1,2-epoxydecane.

The above epoxy compounds may be used alone or in combination of two or more.

The mixing ratio of the epoxy compounds is preferably from 0.01 to 10 parts by weight, more preferably from 0.05 to 5 parts by weight, per 100 parts by weight of the polyether oil. If the compounding ratio is too small, the effect of suppressing the formation of sludge will not be improved, and if too large, the effect corresponding to the increase in the compounding amount will not be obtained and the compatibility with the polyether oil will decrease.

The refrigerating machine oil composition of the present invention contains mineral oil, poly-α-olefin oil, alkylbenzene oil, polyol ester oil, and polyether oil other than the polyether oil of the present invention as long as the compatibility with the HFC refrigerant is not impaired. A polyether oil, a perfluoropolyether oil, a fluorinated silicone oil, a phosphate oil, and the like may be mixed. The mixing ratio is 1 to 30 with respect to 100 parts by weight of the refrigerating machine oil in the present invention.
0 parts by weight is preferable, and 10 to 100 parts by weight is more preferable.

The refrigerating machine oil composition of the present invention contains an antioxidant, a metal deactivator, and an antioxidant which are usually used as additives for the refrigerating machine oil within a range satisfying the performance of the refrigerating machine oil aimed at by the present invention. A foaming agent can be used in combination.

Examples of the antioxidant include hindered phenol-based, amine-based, and sulfur-based antioxidants.
6-di-t-butyl-4-methylphenol, 4, 4 '
-Methylenebis (2,6-di-t-butylphenol), 2,2'-thiobis (4-methyl-6-t-butylphenol), trimethyldihydroquinone, p,
p'-dioctyldiphenylamine, 3,7-dioctylphenothiazine, alkylphenothiazine-1-carboxylate, phenyl-2-naphthylamine, 2,6
-Di-t-butyl-2-dimethyl-p-cresol, 5
-Ethyl-10,10'diphenylphenazaline, alkyl disulfide and the like can be used.

Examples of the metal deactivator include alizanin, chilizanine, benzotriazole, oil-soluble benzotriazole, mercaptobenzotriazole and the like.
Examples of the antifoaming agent include dimethylpolysiloxane, fluorinated aliphatic hydrocarbon, and perfluoropolyether.

The refrigerating machine oil composition of the present invention contains various HFs.
C type refrigerants can be used alone or in combination. The ratio of the refrigerating machine oil to the HFC-based refrigerant in the refrigerating machine oil composition of the present invention is not particularly limited.

The HFC-based refrigerant used in the present invention includes HFC-32, HFC-125 and HFC-134.
a, 1,1,1-trifluoroethane (hereinafter, HFC-
143a), 1,1-difluoroethane and 1,1,2,2-tetrafluoroethane, or a mixture of two or more thereof.

As the mixture, in particular, HFC-32, HF
A mixture of C-125 and HFC-134a,
Preferred is 125, a mixture of HFC-134a and HFC-143a, a mixture of HFC-125 and HFC-143a or a mixture of HFC-32 and HFC-125.

[0058]

EXAMPLES Examples 1 to 3 are synthesis examples of various polyethers. Examples 4 to 11 are working examples, and examples 12 to 15 are comparative examples.

Example 1 150 parts of p-tert-butylphenol and 2.5 parts of potassium hydroxide were charged into a reactor.
After stirring and mixing at 80 ° C. for 30 minutes, the temperature was raised to 120 ° C., and dehydration was performed under reduced pressure for 3 hours. After the dehydration, 696 parts of propylene oxide (hereinafter referred to as PO) was supplied to the reactor over 5 hours while maintaining the temperature at 110 ° C. The internal pressure of the reactor rises to a maximum of about 5 atm with the supply of PO,
The internal pressure decreased with the progress of the reaction. After aging for 2 hours after the completion of PO supply, and after confirming that the internal pressure is constant,
Degas for 1 hour at 20 ° C.

After the reactor was returned to normal pressure, an inorganic acid equivalent to the amount of potassium in the reactor was added for neutralization while stirring was continued, and 2 parts of synthetic magnesium silicate was added as an adsorbent.
The mixture was heated to 120 ° C., stirred for 30 minutes, dehydrated under reduced pressure for 3 hours, filtered under pressure, and subjected to a hydroxyl value of 70.0 mg KO.
829 parts of a raw material polyoxyalkylene glycol having an H / g of 40 ° C. and a kinematic viscosity of 70.3 cSt were obtained.

Of the raw materials, 642 parts of the raw material polyoxyalkylene glycol and 52.1 parts of potassium hydroxide were charged into a reactor, and the mixture was stirred and mixed at 80 ° C. for 30 minutes. Dehydrated. After dehydration, replace with nitrogen
After sufficiently removing oxygen in the reactor, 46.8 parts of methyl chloride was supplied to the reactor over 5 hours while maintaining the temperature at 70 ° C. The internal pressure of the reactor increased with the supply of methyl chloride, but decreased with the progress of the reaction. After completion of the supply of methyl chloride, the mixture was aged for 3 hours, and after confirming that the internal pressure was constant, degassing was performed at 120 ° C. under reduced pressure for 1 hour.

After the reactor was returned to normal pressure, 400 parts of water was added to the reactor while stirring was continued, the mixture was stirred at 80 ° C., the aqueous layer was removed, and 3.2 parts of phosphoric acid was added to the remaining oil layer. And neutralized, and 6.5 parts of synthetic magnesium silicate was added as an adsorbent. After stirring at 120 ° C. for 30 minutes, the mixture was dehydrated under reduced pressure for 3 hours, followed by pressure filtration, and a kinematic viscosity at 40 ° C. of 43.0 c.
St polyether (hereinafter referred to as polyether-1)
I got

The hydroxyl value of polyether-1 is 3.83 m
gKOH / g, and it was confirmed that 95% of the raw material polyoxyalkylene glycol was converted to terminally methylated polyoxyalkylene glycol.

Example 2 150 parts of p-tert-butylphenol and 2.5 parts of potassium hydroxide were charged into a reactor.
After stirring and mixing at 80 ° C. for 30 minutes, the temperature was raised to 120 ° C., and dehydration was performed under reduced pressure for 3 hours. After dehydration, 178 parts of propylene oxide (hereinafter referred to as PO) was supplied to the reactor over 2 hours while maintaining the temperature at 110 ° C. The internal pressure of the reactor rises to a maximum of about 3 atm with the supply of PO,
The internal pressure decreased as the reaction progressed. After completion of PO supply, the mixture was aged for 2 hours, and after confirming that the internal pressure was constant, 308 parts of methyl glycidyl ether was continuously supplied over 2 hours. Since the internal pressure hardly changes before and after the supply, the reaction is continued for 3 hours after the end of the supply, and then the pressure is reduced to 120 ° C.
For 2 hours.

After the reactor was returned to normal pressure, an inorganic acid equivalent to the amount of potassium in the reactor was added for neutralization while stirring was continued, and 2 parts of synthetic magnesium silicate was added as an adsorbent.
The temperature was raised to 120 ° C., and the mixture was stirred for 30 minutes, dehydrated under reduced pressure for 3 hours, continuously filtered under pressure, and subjected to a hydroxyl value of 88.5 mg KO.
710 parts of a raw material polyoxyalkylene glycol having an H / g of 40 ° C. and a kinematic viscosity of 108 cSt were obtained.

646 parts of the raw material polyoxyalkylene glycol and 84.1 parts of potassium hydroxide are charged into the reactor, and the mixture is stirred and mixed at 80 ° C. for 30 minutes. Dehydrated. After dehydration, replace with nitrogen
After sufficiently removing oxygen in the reactor, 65.7 parts of methyl chloride was supplied to the reactor over 5 hours while maintaining the temperature at 70 ° C. The internal pressure of the reactor increased with the supply of methyl chloride, but decreased as the reaction proceeded. After completion of the supply of methyl chloride, the mixture was aged for 5 hours, and after confirming that the internal pressure was constant, degassing was performed at 120 ° C. under reduced pressure for 1 hour.

After the reactor was returned to normal pressure, 400 parts of water was added to the reactor while stirring was continued, and the mixture was stirred at 80 ° C. After removing the aqueous layer, 26 parts of phosphoric acid was added to the remaining oil layer. After neutralization, 6.5 parts of synthetic magnesium silicate was added as an adsorbent. After stirring at 120 ° C. for 30 minutes, the mixture was dehydrated under reduced pressure for 3 hours, followed by pressure filtration, and a kinematic viscosity at 40 ° C. of 62.7 cS
Thus, a polyether of t (hereinafter, referred to as polyether-2) was obtained.

The hydroxyl value of polyether-2 is 1.44 m
gKOH / g, and it was confirmed that 98.7% of the raw material polyoxyalkylene glycol was converted to terminally methylated polyoxyalkylene glycol.

Example 3 206 parts of octylphenol and 2.5 parts of potassium hydroxide were charged into a reactor and heated at 80 ° C. for 30 minutes.
After stirring and mixing for minutes, the mixture was heated to 120 ° C. and dehydrated under reduced pressure for 3 hours. After the dehydration, 696 parts of PO was supplied to the reactor over 5 hours while maintaining the temperature at 110 ° C. The internal pressure of the reactor rises to a maximum of about 5 atm with the supply of PO,
The internal pressure decreased with the progress of the reaction. After aging for 2 hours after the completion of PO supply, and after confirming that the internal pressure is constant,
Degas for 1 hour at 20 ° C.

After the reactor was returned to normal pressure, an inorganic acid equivalent to the amount of potassium in the reactor was added to neutralize while continuing to stir, and 2 parts of synthetic magnesium silicate was added as an adsorbent.
After the temperature was raised to 120 ° C., and the mixture was stirred for 30 minutes, it was dehydrated under reduced pressure for 3 hours, and then subjected to pressure filtration.
827 parts of a raw material polyoxyalkylene glycol having a kinematic viscosity of 70 cSt were obtained.

640 parts of the raw material polyoxyalkylene glycol and 52.1 parts of potassium hydroxide are charged into the reactor, and the mixture is stirred and mixed at 80 ° C. for 30 minutes. Dehydrated. After dehydration, replace with nitrogen
After sufficiently removing oxygen in the reactor, 46.8 parts of methyl chloride was supplied to the reactor over 5 hours while maintaining the temperature at 70 ° C. The internal pressure of the reactor increased with the supply of methyl chloride, but decreased with the progress of the reaction. After completion of the supply of methyl chloride, the mixture was aged for 3 hours, and after confirming that the internal pressure was constant, degassing was performed at 120 ° C. under reduced pressure for 1 hour.

After the reactor was returned to normal pressure, 400 parts of water was added to the reactor while stirring was continued, the mixture was stirred at 80 ° C., the aqueous layer was removed, and 3.2 parts of phosphoric acid was added to the remaining oil layer. And neutralized, and 6.5 parts of synthetic magnesium silicate was added as an adsorbent. After stirring at 120 ° C. for 30 minutes, the mixture was dehydrated under reduced pressure for 3 hours, followed by pressure filtration, and a kinematic viscosity at 40 ° C. of 42 cSt.
(Hereinafter, referred to as polyether-3) was obtained.

The polyether-3 has a hydroxyl value of 3.83 m.
gKOH / g, and it was confirmed that 95% of the raw material polyoxyalkylene glycol was converted to terminally methylated polyoxyalkylene glycol. Table 1 shows the structures of the polyethers 1-3.

[0074]

[Table 1]

[Examples 4 to 15] In a HFC-134a refrigerant atmosphere, a steel ring and a steel block were used as test materials, and the wear amount of the steel block surface was measured by a Falex test (ASTMD 2714). The test condition was a test temperature of 100
C., test time: 1 hour, ambient gas pressure: 600 KPa. In addition, the test result was shown by the relative value when the abrasion loss which used HCFC-22 as a refrigerant | coolant and naphthenic oil as a refrigerating machine oil was 1.0 [abrasion test].

In an atmosphere of HFC-134a refrigerant,
The chemical stability test was performed by the shield tube test method. The shield tube test method uses a refrigerant in a glass container,
Approximately 1 cc of each refrigerating machine oil and Fe, Cu, and Al wires are sealed, heated, and maintained at 175 ° C. for 14 days to check whether the refrigerating machine oil has discolored or formed sludge. Presence].

The degree of discoloration of the refrigerating machine oil was evaluated by observing the degree of discoloration of the refrigerating machine oil after completion of the test, and was evaluated as ○ when no discoloration was observed, Δ when slightly changed, and X when considerably discolored.

The following abbreviations are used in Tables 2 and 3. TPPT: triphenylphosphorothionate TOPT: trioctylphosphorothionate VCHO: vinylcyclohexene dioxide TCP: tricresyl phosphate

[0079]

[Table 2]

[0080]

[Table 3]

[0081]

Industrial Applicability The refrigerating machine oil composition of the present invention has the advantages of a refrigerating machine oil comprising a specific polyether, which has the advantages of electrical insulation,
Shows excellent abrasion resistance, thermal and chemical stability while maintaining features such as compatibility with HFC refrigerants and low moisture absorption.
In order to suppress the generation of sludge, any type of compressor, such as a reciprocating type, a scroll type, and a rotary type, can be sufficiently used.

Continued on the front page F term (reference) 4H104 BB09C BB45A BB46A BH03C BH06C LA03 LA13 LA14 LA20 PA20

Claims (4)

[Claims] 1. A refrigerating machine oil composition comprising a refrigerating machine oil comprising a polyether represented by the following general formula (1) and a phosphorothionate. R ^1- [X-OR ⁴ ] _s (1) wherein R ¹ is an s-valent group having an aromatic nucleus, and X is an average of q -OR ² -and an average of r -OR ^3-. R ² is an ethylene group optionally having a methyl group or an ethyl group, R ³ is an ethylene group having an alkoxymethyl group having 1 to 4 carbon atoms in the alkoxy group, and R ⁴ is a carbon atom Shows the alkyl groups of Formulas 1 to 10. s is an integer of 1 to 6, q and r are 0 or more, and (q + r) × s is 3 to
The number is 80. 2. The refrigerator oil composition according to claim 1, wherein the phosphorothionates are alkyl phosphorothionates or aryl phosphorothionates. 3. The refrigerating machine oil composition according to claim 1, which contains a phosphate ester or an epoxy compound. 4. The refrigerating machine oil composition according to claim 1, further comprising a hydrofluorocarbon-based refrigerant.