JP2000212584A - Refrigerator oil composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a refrigerator oil composition capable of efficiently carrying out lubrication and improving sealing properties and refrigeration efficiency by including a base oil comprising a refrigerant consisting essentially of carbonic acid gas, and specific polyethers. SOLUTION: This refrigerator oil composition comprises a base oil comprising (A) a refrigerant consisting essentially of carbonic acid gas, and (B) polyethers represented by formula I [R1 is an n-valent group having an aromatic nuclear; R2 is a 2-6C polymethylene, a group having one or more Hs of the polymethylene substituted with a group represented by formula II (R4 is methylene or ethylene; R5 is a 2-6C polymethylene or the like; R6 is H, a 1-10C alkyl or the like; p is 0-80), or the like; R3 is H, a 1-10C alkyl, a 2-10C acyl; n is 1-6; m is a number regulated so that the average value of m×n may be 3-80]. The weight ratio of the components A/B is preferably within the range of (95/5)-(30/70).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a refrigerating machine oil composition, and more particularly, to a refrigerating machine oil composition using a refrigerant containing carbon dioxide as a main component.

[0002]

2. Description of the Related Art Generally, in a compression refrigerating cycle of a refrigerating machine, for example, a compression refrigerating machine comprising a compressor, a condenser, an expansion valve, and an evaporator, a mixed liquid of a refrigerant and a lubricating oil is sealed in a closed system. It has a structure that circulates inside. Conventionally, dichlorodifluoromethane (CFC-12) and chlorodifluoromethane (HCFC-22) are often used as refrigerants in such compression refrigerators, and synthetic oils such as alkylbenzene compounds and various oils are used as lubricating oils. Mineral oils have been used.

However, the above-mentioned CFC-12 and HCFC-2
Since chlorofluorocarbons and hydrochlorofluorocarbons such as No. 2 may cause environmental pollution such as destruction of the ozone layer existing in the stratosphere, regulations on the use thereof have recently become stricter worldwide.

For this reason, switching to hydrofluorocarbon as a new refrigerant has been carried out. 1,1,1,
Hydrofluorocarbons typified by 2-tetrafluoroethane (HFC-134a) do not have a risk of destroying the ozone layer, but have a long life in the atmosphere, and thus may have an effect on global warming.

[0005] In recent years, the use of carbon dioxide as a natural refrigerant having no such problems has been studied. Carbon dioxide is harmless to the environment and is excellent in terms of safety for humans. Furthermore, (1) it is economical because the pressure is close to the optimal level, (2) the pressure ratio is very small compared to conventional refrigerants, and (3) it is compatible with ordinary lubricating oils and structural materials of machines. (4) it is readily available everywhere, and (5) it is very inexpensive because it does not require recovery. It has been conventionally used as a refrigerant for refrigerators and the like.

However, when such a carbon dioxide gas is used as a refrigerant for a refrigerator, if a synthetic oil such as an alkylbenzene-based compound or a base oil such as a mineral oil, which is generally used conventionally, is used, the lubricating performance is insufficient. Therefore, there were problems such as insufficient wear resistance and poor sealing performance, resulting in poor long-term stability. Further, in a system using carbon dioxide gas, R
Since the discharge pressure is higher and the viscosity of the lubricating oil is lower than that of a system using -134a or the like, there is also a problem that the sealing performance of the system is deteriorated and a long-term stable use cannot be performed.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and it is possible to efficiently lubricate a compression refrigeration cycle using a refrigerant containing carbon dioxide as a main component. It is an object of the present invention to provide a refrigerating machine oil composition capable of improving performance and sealability and improving refrigerating efficiency, and a lubrication method using the composition.

[0008]

That is, the present invention is as follows. (1) A refrigerating machine oil composition comprising: (A) a refrigerant mainly containing carbon dioxide gas; and (B) a base oil comprising a polyether represented by the following formula (1). (2) A method for lubricating a compression-type refrigerator, comprising using the above-mentioned refrigerator oil composition.

R ¹ -[(OR ² ) _m -OR ³ ] _n (1) wherein R ¹ is an n-valent group having an aromatic nucleus, and R ² is ² carbon atoms.
Or a group in which at least one of hydrogen atoms of the polymethylene group has been substituted with an alkyl group having 1 to 20 carbon atoms, or at least one of hydrogen atoms of the polymethylene group has the following formula: A group substituted with a group represented by (2),
R ³ represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an acyl group having 2 to 10 carbon atoms. n is an integer of 1 to 6, and m is a number such that the average value of m × n is 3 to 80.

[0010] _{^{-R 4 - (OR 5) p}} -OR 6 ··· (2) provided that, R ⁴ is a methylene group or an ethylene group, R ⁵ is a hydrogen atom polymethylene group or said polymethylene group having 2 to 6 carbon atoms R ⁶ represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an acyl group having 2 to 10 carbon atoms. p is 0-8
It is an integer of 0.

[0011]

DETAILED DESCRIPTION OF THE INVENTION (A) used in the present invention
The main component of the refrigerant is carbon dioxide. Although only carbon dioxide can be used, hydrocarbons, R-
Hydrofluorocarbons (or hydrochlorofluorocarbons) such as 134a, ethers and the like may be used in combination. When using carbon dioxide and other compounds together,
The proportion of carbon dioxide in the total refrigerant is preferably 50 to 100% by weight, particularly preferably 80 to 100% by weight. It is preferable to use 100% by weight, that is, only carbon dioxide gas as the refrigerant.

Further, as the base oil (B), the following formula (1)
The polyether derivative represented by is used. R ¹ -[(OR ² ) _m -OR ³ ] _n (1) where R ¹ is an n-valent group having an aromatic nucleus, and R ² is ² carbon atoms.
Or a group in which at least one hydrogen atom of the polymethylene group is substituted with an alkyl group having 1 to 20 carbon atoms, or at least one hydrogen atom of the polymethylene group is represented by the following formula (2): R ³ represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a group having 2 to 1 carbon atoms.
And 0 represents an acyl group. n is an integer of 1 to 6, and m is m
X is a number such that the average value of n is 3 to 80.

[0013] _{^{-R 4 - (OR 5) p}} -OR 6 ··· (2) provided that, R ⁴ is a methylene group or an ethylene group, R ⁵ is a hydrogen atom polymethylene group or said polymethylene group having 2 to 6 carbon atoms R ⁶ represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an acyl group having 2 to 10 carbon atoms. p is 0-8
It is an integer of 0.

In the present invention, R ¹ of the polyether represented by the formula (1) is an n-valent group having an aromatic nucleus. n is an integer of 1 to 6;
An integer of 2 is preferred.

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, and includes a phenyl group, a biphenylyl group, a naphthyl group, or a group having an alkyl group portion. . 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.

Examples of the divalent to hexavalent group having an aromatic nucleus include a residue obtained by removing 1 to 5 hydrogen atoms of an aryl group or an aralkyl group, 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. Desirable 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 number of carbon atoms of these aryl groups and aralkyl groups is preferably 14 or less from the viewpoint of compatibility with hydrocarbons. If the number of carbon atoms is larger than 14, the compatibility with hydrocarbon refrigerants is not sufficiently reduced, and the expected effect is not obtained. No longer available. Preferred aryl groups have 6 to 12 carbon atoms, and preferred aralkyl groups have 7 to 12 carbon atoms.

R ² in the formula (1) is a polymethylene group having 2 to 6 carbon atoms, a group in which at least one hydrogen atom of the polymethylene group is substituted by an alkyl group having 1 to 20 carbon atoms, or A group in which at least one hydrogen atom of the group is substituted with a group represented by the following formula (2).

[0023] _{^{-R 4 - (OR 5) p}} -OR 6 ··· (2) provided that, R ⁴ is a methylene group or an ethylene group, R ⁵ is a hydrogen atom polymethylene group or said polymethylene group having 2 to 6 carbon atoms R ⁶ represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an acyl group having 2 to 10 carbon atoms. p is 0-8
It is an integer of 0.

R ² is an ethylene group, a group in which at least one hydrogen atom of the ethylene group is substituted by an alkyl group having 1 to 20 carbon atoms, and at least one hydrogen atom of the ethylene group is represented by the formula (2). And a group substituted with a group such as a trimethylene group, a tetramethylene group, or a pentamethylene group. R ² is a group in which at least one hydrogen atom of an ethylene group is substituted by an alkyl group having 1 to 20 carbon atoms (hereinafter, referred to as R ²¹ ), and at least one hydrogen atom of the ethylene group is represented by the formula (2). It represented has been substituted with group (hereinafter referred to as R ^22), or an ethylene group is particularly preferred.

The substituent for R ²¹ has 1 to 1 carbon atoms.
An alkyl group of 4 is preferable, and an alkyl group having 1 to 2 carbon atoms, that is, a methyl group or an ethyl group is particularly preferable. R
^{As 21} , an ethylene group having a methyl group or an ethylene group having an ethyl group is preferable. More specifically, methylethylene group (propylene group), ethylethylene group; 1,1-dimethylethylene group; 1,2-dimethylethylene group; n-propylethylene group; isopropylethylene group; 1-ethyl-1-methyl Examples include an ethylene group. In the formula (2), R ⁴ is a methylene group or an ethylene group, and a methylene group is preferable.

R ⁵ is preferably an ethylene group, a group in which at least one hydrogen atom of the ethylene group has been substituted by an alkyl group having 1 to 20 carbon atoms, a trimethylene group, a tetramethylene group or a pentamethylene group. R ⁵ is the same group as R ²¹ above,
Alternatively, an ethylene group is particularly preferred.

Specific examples of R ⁵ include a methylethylene group (propylene group), an ethylethylene group; a 1,1-dimethylethylene group; a 1,2-dimethylethylene group; an n-propylethylene group; Examples thereof include an ethyl-1-methylethylene group and an ethylene group.

R ⁶ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an acyl group having 2 to 10 carbon atoms,
Preferred is an alkyl group having 4 to 4 carbon atoms or an acyl group having 2 to 4 carbon atoms. p is an integer of 0 to 80, preferably 0 to 50, and particularly preferably 0 to 10. Most preferably, it is 0.

R ²² is (methoxymethyl) ethylene, (ethoxymethyl) ethylene, (propoxymethyl) ethylene, (butoxymethyl) ethylene,
-Methoxymethyl-2-methylethylene group, 1,2-bis (methoxymethyl) ethylene group; (methoxyethyl)
Ethylene group; (ethoxyethyl) ethylene group; 1,1-
Bis (ethoxyethyl) ethylene group; 2-methoxy-
1,3-propylene group and the like.

It is particularly preferred that (OR ² ) in one molecule comprises a combination of an oxyethylene group, (OR ²¹ ) and (OR ²² ). The oxyethylene group is preferably formed by opening the ring of ethylene oxide.

(OR ²¹ ) is preferably formed by ring-opening an alkylene oxide. As the alkylene oxide, propylene oxide, 1,2-butylene oxide,
Examples thereof include 2,3-butylene oxide and isobutylene oxide.

Examples of (OR ²² ) include those formed by ring-opening alkyl glycidyl ethers such as methyl glycidyl ether, ethyl glycidyl ether, propyl glycidyl ether and butyl glycidyl ether. In addition, epihalohydrin and H (OR ⁵ ) _p -OR ⁶
And those formed by ring-opening a reaction product with a polyether monool represented by

(OR ² ) may be one kind selected from these, or two or more kinds selected from these.
In the case of two or more kinds, the bonds thereof may be block-like or random-like. (OR ² ) preferably has an oxypropylene group as essential from the viewpoint of viscosity characteristics.

R ^{3 in the} formula (1) is a hydrogen atom, having 1 to 1 carbon atoms.
It is an alkyl group having 0 or an acyl group having 2 to 10 carbon atoms. The alkyl group having 1 to 10 carbon atoms is linear, branched,
Any of a ring shape may be sufficient. Specific examples of the alkyl group include
Methyl group, ethyl group, n-propyl group, isopropyl group, butyl group, pentyl group, hexyl group, heptyl group,
Octyl, nonyl, decyl, cyclopentyl,
And a cyclohexyl group.

Examples of the acyl group having 2 to 10 carbon atoms include residues of aliphatic carboxylic acids such as acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, capric acid and cyclohexanecarboxylic acid. From the viewpoint of compatibility with hydrocarbons, R ³ is preferably a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an acyl group having 2 to 4 carbon atoms.

N in the formula (1) is an integer of 1 to 6,
Is 2 or more, two or more [(OR ² ) _m —O
R ³ ] may be the same or different. n
Is a number from 1 to 6 and mxn is from 3 to 80. mxn
Exceeds 80, the object of the present invention cannot be sufficiently achieved from the viewpoint of kinematic viscosity. A preferred value of m × n is 3 to 40, and a more preferred value of m × n is 3 to 15.

The polyether represented by the formula (1) used in the present invention can be synthesized by various methods. The polyether represented by the formula (1) wherein R ³ is a hydrogen atom is represented by the formula R ¹
It is obtained by adding an alkylene oxide and / or an alkyl glycidyl ether to a compound represented by (OH) _n (wherein R ¹ is an n-valent group having an aromatic nucleus, and n is an integer of 1 to 6). The polyethers of the formula (1) wherein R ³ is an alkyl group having 1 to 10 carbon atoms are represented by the formula R ¹ (OH) _n (wherein R ¹ is an n-valent group having an aromatic nucleus, and n is 1 to 1) Integer of 6.)
A polyether obtained by adding an alkylene oxide and / or an alkyl glycidyl ether to the compound represented by the formula (1) is alcoholated with an alkali, and then reacted with an alkyl monohalide to effect etherification. As the alkyl monohalide, a compound having 1 carbon atom
And a chloride, bromide or iodide of an alkyl group of 10 to 10.

The polyethers in which R ³ is an acyl group having 2 to 10 carbon atoms can be obtained by the method represented by the formula R ¹ -[(OR ² )
_m- OH] A method of reacting a hydroxyl group of a polyether represented by _n with an aliphatic carboxylic acid having 2 to 10 carbon atoms, or a reactive derivative thereof such as an acid anhydride, an acid halide or an ester thereof, or After converting the hydroxyl group of the ether or its derivative to a sulfonic ester or halide,
This can be obtained by a method of reacting the carboxylic acid or a salt thereof, or the like.

By simultaneously adding the alkylene oxide and the alkyl glycidyl ether to the compound represented by the above formula R ¹ (OH) _n , (OR ²¹ ) and (O
Binding of R ²²⁾ include the random form is obtained, as by performing the addition of alkylene oxide and an alkyl glycidyl ether separately from the (OR ²¹⁾ coupling the block-shaped (OR ²²⁾ is obtained.

Specific examples of the aliphatic carboxylic acid include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, capric acid, and cyclohexanecarboxylic acid. When esterification is performed using the aliphatic carboxylic acid or acid anhydride, or when esterification is performed by transesterification using the ester of the aliphatic carboxylic acid, sulfuric acid or p-
An acid catalyst such as toluenesulfonic acid is used. on the other hand,
When esterification is performed using an acid halide, amines and alkalis are used as the dehydrohalogenating agent.

The kinematic viscosity of the polyethers at 40 ° C. in the present invention is preferably from 1 to 10,000 mm ² / s,
1000 mm ² / s is more preferred. 5-500mm ²
/ S is particularly preferred, and 5 to 150 mm ² / s is most preferred.

The polyethers used in the present invention preferably have an acid value of 1 mgKOH / g or less. 5 water
It is preferably at most 00 ppm, particularly preferably at most 200 ppm. In order to remove impurities, contaminants, and moisture that affect thermal stability, those treated with distillation, filtration, an adsorbent, and a dehydrating agent are preferable.

In the refrigerating machine oil composition of the present invention, one kind of the polyethers may be used alone or two or more kinds may be used in combination. In the present invention, the amounts of the (A) refrigerant and (B) base oil used are 99% by weight in the ratio (A) / (B).
/ 1 to 10/90.

If the amount of (A) is less than the above range, the refrigerating capacity may be reduced, and if it is more than the above range, the lubricating performance may be undesirably reduced. From such a viewpoint, the weight ratio of (A) / (B) is more preferably in the range of 95/5 to 30/70.

The refrigerator oil composition of the present invention may contain various known additives such as tricresyl phosphate (TC
Extreme pressure agents such as phosphoric acid esters such as P) and phosphites such as trisnonylphenyl phosphite; phenolic and amine antioxidants; stabilizers such as phenylglycidyl ether, cyclohexene oxide and epoxidized soybean oil A copper deactivator such as benzotriazole or a derivative thereof; and an antifoaming agent such as silicone oil or fluorinated silicone oil. Further, load-bearing additives, chlorine scavengers, detergents / dispersants, viscosity index improvers, oil agents, rust inhibitors, corrosion inhibitors, pour point depressants and the like can be added as required. These additives are usually contained in the composition of the present invention in an amount of 0.5 to 10% by weight.

The refrigerating machine oil composition of the present invention can be used as a lubricating oil for various refrigerating machines. In particular, the present invention can be applied to a compression refrigeration cycle of a compression refrigeration machine.
It can be preferably applied to a normal compression refrigeration cycle including an evaporator. That is, the present invention is a lubricating method for a compression-type refrigerator characterized by using the above-mentioned refrigerator oil composition.

[0047]

Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the examples. “Parts” indicates “parts by weight”. Various polyethers were synthesized in Examples 1 to 7, and the performance of the refrigerating machine oil was evaluated by the following method (Examples). Further, in Example 8, the performance was similarly evaluated with respect to a naphthenic mineral oil suniso 4GS (hereinafter, referred to as S oil) manufactured by Nippon Sun Oil (Comparative Example). The results are shown in Table 1 together with the kinematic viscosity (mm ² / s) of each sample oil.

(1) Dissolution amount of carbon dioxide gas Carbon dioxide gas was blown into 100 g of sample oil under a pressurized condition of 50 kg / cm ² , and the dissolved amount (% by weight) of carbon dioxide gas in the oil was measured.

(2) Falex Seizure Test (Lubricity Test) In accordance with ASTM D-3233-73, a Falex seizure load (Lbs) was measured for each sample oil to evaluate lubricity.

(3) Shield tube test (heat and chemical stability test) Fe, Cu, and Al wires were put in a glass tube, and the ratio of carbon dioxide / sample oil / water was 0.5 g / 4 g / 0.02 g. The sample was filled and sealed. After holding at 175 ° C. for 14 days, the oil appearance,
The metal appearance, total acid value (mgKOH / g) and the presence or absence of sludge formation were observed.

(Example 1) 108 parts of m-cresol and 2.5 parts of potassium hydroxide were charged into a reactor and heated at 80 ° C.
After stirring and mixing at for 30 minutes, the temperature was raised to 120 ° C., and dehydration was performed under reduced pressure for 3 hours. After the dehydration, 116 parts of propylene oxide (hereinafter, referred to as PO) and 264 parts of ethylene oxide (hereinafter, referred to as EO) were simultaneously fed over 5 hours while maintaining the temperature at 110 ° C. After completion of the feed of PO and EO, the mixture was aged for 2 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, 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, and then filtered under pressure to obtain a polymer having a hydroxyl value (OHV) of 115.4 and a kinematic viscosity of 68 mm ² / s at 40 ° C. Oxyalkylene monool (hereinafter, polyether-
478 parts).

In the formula (1), R ¹ = 3-methylphenyl group, R ² = propylene group / ethylene group (molar ratio of propylene group to ethylene group = 2.0 / 6.0), R ³ = hydrogen atom , M = 8.0 and n = 1.

Example 2 Polyether-1 obtained in Example 1
Was charged into a reactor and stirred and mixed at 80 ° C. for 30 minutes, then heated to 120 ° C. and dehydrated under reduced pressure for 3 hours. After dehydration, the atmosphere in the reactor was replaced with nitrogen three times to sufficiently remove oxygen from the reactor, and then 26.5 parts of methyl chloride was fed to the reactor over 5 hours while maintaining the temperature at 70 ° C. After completion of methyl chloride feed, the mixture was aged, and after confirming that the internal pressure was constant, the pressure was reduced to 120 ° C.
For 1 hour.

After the reactor was returned to normal pressure, 200 parts of water was added to the reactor while stirring was continued. After stirring, the aqueous layer was removed and 2.1 parts of phosphoric acid was added to the remaining oil layer. Then, 4.2 parts of synthetic magnesium silicate was added as an adsorbent. 1
After stirring at 20 ° C. for 30 minutes, the mixture was dehydrated under reduced pressure for 3 hours, followed by pressure filtration to obtain a polyether having a kinematic viscosity of 29 mm ² / s at 40 ° C. (hereinafter referred to as polyether-2).

In the formula (1), R ¹ = 3-methylphenyl group, R ² = propylene group / ethylene group (molar ratio of propylene group to ethylene group = 2.0 / 6.0), R ³ = methyl group , M = 8.0 and n = 1.

Example 3 A reactor was charged with 206 parts of octylphenol and 2.5 parts of potassium hydroxide.
After stirring and mixing at 30 ° C. for 30 minutes, the mixture was heated to 120 ° C. and dehydrated under reduced pressure for 3 hours. After dehydration, 529 parts of PO were fed over 5 hours while maintaining the temperature at 110 ° C. After completion of the PO feed, the mixture was aged for 2 hours, and after confirming that the internal pressure was constant, deaeration was performed at 120 ° C. under reduced pressure for 1 hour.

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, and continuously subjected to pressure filtration, and 717 parts of polyoxyalkylene monool (hereinafter referred to as polyether-3) having an OHV of 78.0 was added. Obtained. In the formula (1), R ¹ = octylphenyl group, R ² = propylene group, R ³ = hydrogen atom,
It was a polyether where m = 8.8 and n = 1.

Example 4 Polyether-3 obtained in Example 3
Was charged into a reactor and stirred and mixed at 80 ° C. for 30 minutes, then heated to 120 ° C. and dehydrated under reduced pressure for 3 hours. After dehydration, the atmosphere in the reactor was replaced with nitrogen three times to sufficiently remove oxygen from the reactor, and 16.8 parts of methyl chloride was fed to the reactor over 5 hours while maintaining the temperature at 70 ° C. After completion of the methyl chloride feed, the mixture was aged, and after confirming that the internal pressure was constant, the pressure was reduced to 120 ° C.
For 1 hour.

After the reactor was returned to normal pressure, 150 parts of water was added to the reactor while stirring, and after stirring, the aqueous layer was removed and 1.2 parts of phosphoric acid was added to the remaining oil layer. And 2.3 parts of synthetic magnesium silicate was added as an adsorbent. 1
After stirring at 20 ° C. for 30 minutes, the mixture was dehydrated under reduced pressure for 3 hours, followed by filtration under pressure to obtain a polyether having a kinematic viscosity of 54 mm ² / s at 40 ° C. (hereinafter referred to as polyether-4). In the formula (1), the polyether represented by R ¹ = octylphenyl group, R ² = propyl group, R ³ = methyl group, m = 8.8, and n = 1.

Example 5 Polyether-3 obtained in Example 3
Were charged into a reactor, and 230 parts of
The mixture was heated to 40 ° C. and reacted while distilling off acetic acid as a by-product. After reacting at 140 ° C. for 3 hours, deacetic acid and deaeration were performed under reduced pressure. As a result, 241 parts of an acetic acid ester of polyether-3 (hereinafter referred to as polyether-5) having a kinematic viscosity at 40 ° C of 69 mm ² / s was obtained. In the formula (1), R ¹ = octylphenyl group, R ² = propyl group, R ³ = acetyl group, m
= 8.8, n = 1.

Example 6 pt-butylphenol 150
And 2.5 parts of potassium hydroxide were charged into the reactor and stirred and mixed at 80 ° C. for 30 minutes, then heated to 120 ° C. and dehydrated under reduced pressure for 3 hours. After dehydration, 178 parts of PO was fed into the reactor over 2 hours while maintaining the temperature at 110 ° C. Subsequently, methyl glycidyl ether 308
The part was fed over 2 hours. After the feed was completed, the reaction was continued for 3 hours, followed by degassing at 120 ° C for 2 hours under reduced pressure.

After the reactor was returned to normal pressure, an inorganic acid in an amount equivalent to the amount of potassium in the reactor was neutralized 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.
As a result, 623 parts of a polyoxyalkylene monool (hereinafter referred to as polyether-6) having a kinematic viscosity of 108 mm ² / s at 40 ° C. and H / g was obtained.

In the formula (1), R ¹ = 4-t-butylphenyl group, R ² = propylene group / (methoxymethyl)
Ethylene group (molar ratio of propylene group to (methoxymethyl) ethylene group = 3.0 / 3.5), R ³ = hydrogen atom, m
= 6.5, n = 1.

Example 7 Polyether-6 obtained in Example 6
Was charged into a reactor and stirred and mixed at 80 ° C. for 30 minutes, then heated to 120 ° C. and dehydrated under reduced pressure for 3 hours. After dehydration, the atmosphere in the reactor was replaced with nitrogen and oxygen in the reactor was sufficiently removed, and 29.6 parts of methyl chloride was fed over 5 hours while maintaining the temperature at 70 ° C. After completion of the methyl chloride feed, the mixture was aged, and after confirming that the internal pressure was constant, degassing was performed at 120 ° C. under reduced pressure for 1 hour.

After returning the reactor to normal pressure, stirring was continued.
175 parts of water was added to the reactor and stirred at 80 ° C.
11.5 parts of phosphoric acid was added to the remaining oil layer except the water layer.
Neutralize and 6.5 g of synthetic magnesium silicate as adsorbent
Added. After stirring at 120 ° C for 30 minutes, the pressure was reduced for 3 hours.
Dehydration, followed by pressure filtration, kinematic viscosity at 40 ℃ 63mm
^Two/ S of polyether (polyether-7) was obtained.

In the formula (1), R ¹ = 4-t-butylphenyl group, R ² = propylene group / (methoxymethyl)
Ethylene group (molar ratio of propylene group to (methoxymethyl) ethylene group = 3.0 / 3.5), R ³ = methyl group, m
= 6.5, n = 1.

[0068]

[Table 1]

[0069]

According to the present invention, it is possible to provide a refrigerating machine oil composition which is excellent in lubricating performance in a carbon dioxide gas atmosphere as a refrigerant and has a high sealing property.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C10N 30:06 40:30

Claims (5)

[Claims] 1. A refrigerating machine oil composition comprising: (A) a refrigerant mainly containing carbon dioxide gas; and (B) a base oil comprising a polyether represented by the following formula (1). R ¹ -[(OR ² ) _m -OR ³ ] _n (1) where R ¹ is an n-valent group having an aromatic nucleus, and R ² is ² carbon atoms.
Or a group in which at least one hydrogen atom of the polymethylene group is substituted with an alkyl group having 1 to 20 carbon atoms, or at least one hydrogen atom of the polymethylene group is represented by the following formula (2): R ³ represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a group having 2 to 1 carbon atoms.
And 0 represents an acyl group. n is an integer of 1 to 6, and m is m
X is a number such that the average value of n is 3 to 80. —R ⁴ — (OR ⁵ ) _p —OR ⁶ (2) where R ⁴ is a methylene group or an ethylene group, and R ⁵ is a polymethylene group having 2 to 6 carbon atoms or one hydrogen atom of the polymethylene group. The above is a group substituted with an alkyl group having 1 to 20 carbon atoms, and R ⁶ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an acyl group having 2 to 10 carbon atoms. p is 0-8
It is an integer of 0. 2. In the formula (1), R ¹ is a residue obtained by removing 1 to 5 hydrogen atoms of an aryl group, 1 hydrogen atom of an aralkyl group.
The refrigerating machine oil composition according to claim 1, wherein the residue is an aryl group or an aralkyl group excluding -5. 3. The refrigerating machine oil composition according to claim 1, wherein R ³ in the formula (1) is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an acyl group having 2 to 4 carbon atoms. 4. A polyether having a kinematic viscosity at 40 ° C. of 5 to 5.
The refrigerating machine oil composition according to claim 1, 2 or 3, wherein the composition is 1,000 mm ² / s. 5. A method for lubricating a compression type refrigerator, comprising using the refrigerator oil composition according to any one of claims 1 to 4.