JP2002097486A - Refrigerating machine oil composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a refrigerating machine oil composition which sufficiently meets all required performances such as lubricity, heat/hydrolysis stability, refrigerant compatibility, and electrically insulating properties well in balance when used together with a hydrofluorocarbon(HFC) refrigerant or a natural refrigerant such as carbon dioxide and a hydrocarbon, and enables the improvement of the efficiency of a refrigerating system and the high reliability maintenance. SOLUTION: This refrigerating machine oil composition is obtained by adding a phosphorothionate compound to a base oil containing an alicyclic polycarboxylic ester compound.

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 comprising a base oil containing an alicyclic polycarboxylic acid ester compound and a sulfur-based antiwear agent. It is.

[0002]

2. Description of the Related Art In recent years, from the viewpoints of ozone layer depletion and global warming, the replacement of refrigerant and the efficiency of refrigeration systems have been studied. In the replacement of refrigerant, switching from a chlorine-containing refrigerant such as CFC (chlorofluorocarbon) or HCFC (hydrochlorofluorocarbon) to HFC (hydrofluorocarbon) has been promoted. On the other hand, since HFC refrigerants can also be subject to regulation from the viewpoint of global warming, application of natural refrigerants such as carbon dioxide, ammonia, and hydrocarbons is being studied.

[0003] In response to such a trend of replacing refrigerants,
Development of refrigeration oils for alternative refrigerants is underway. Refrigeration oil requires many properties such as lubricity, refrigerant compatibility, heat / hydrolysis stability, electrical insulation, and low hygroscopicity. Compounds that meet these requirements depending on the type and use of the refrigerant Is selected. For example, as refrigeration oil for HFC,
Oxygen-containing compounds such as esters, ethers, and carbonates that are compatible with the refrigerant, and alkylbenzenes that are inferior in refrigerant compatibility but have excellent lubricity and heat / hydrolysis stability are used.

[0004] Among such refrigerating machine oils,
Polyol esters such as those disclosed in JP-A-3-505602 and JP-A-3-1288991, and JP-A-9-1991.
An ester-based refrigerating machine oil containing an alicyclic polycarboxylic acid ester or the like as disclosed in 221690 is excellent in refrigerant compatibility and has high electric insulation, so that it is widely used as a lubricating oil for hermetic refrigerating machines. Have been.

However, when such an ester-based refrigerating machine oil is used as a refrigerating machine oil for HFC, there is a problem that lubricity is inferior to that of a mineral oil / chlorine-based refrigerant system. For this reason, Japanese Patent Application Laid-Open Nos. Hei 3-243697 and Hei 5-7078
5, JP-A-8-209182, JP-A-9-302373
As disclosed in US Pat. Nos. 6,064,064 and 5,867, adding various extreme pressure agents to ester-based refrigerating machine oils in order to improve the lubricating properties of the refrigerating machine oil has been studied. However, there is a tendency that an extreme pressure agent having a higher extreme pressure effect has a lower chemical stability, and in a conventional ester refrigerating machine oil to which an extreme pressure agent according to an ester-based refrigerating machine oil is added, an extreme pressure agent is used. There is a problem in that sludge generated by the deterioration of the base oil itself or other additives may block the capillary.

As described above, under the current situation where the performance required for refrigerating machine oil is extremely severe, all the required performances such as lubricity, heat / hydrolysis stability, refrigerant compatibility, and electrical insulation are required. Ester refrigerating machine oils satisfying well-balanced conditions have not yet been developed.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and when used together with an HFC refrigerant and a natural refrigerant such as carbon dioxide or hydrocarbon, lubricity and lubrication are not improved. To provide a refrigerating machine oil composition that sufficiently satisfies all required performances such as heat / hydrolysis stability, refrigerant compatibility, and electrical insulation in a well-balanced manner, and can improve the efficiency of a refrigeration system and maintain high reliability. The purpose is to:

[0008]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have formulated a phosphorothioate compound into a base oil containing an alicyclic polycarboxylic acid ester compound. By doing so, it was found that the above object was achieved, and the present invention was completed.

That is, the refrigerator oil composition of the present invention comprises a base oil containing an alicyclic polycarboxylic acid ester compound,
It is characterized by adding a phosphorothionate compound.

The alicyclic polycarboxylic acid ester compound according to the present invention includes [I] an alicyclic ring and the following general formula (1): —COOR (1) A compound in which at least two ester groups represented by the following formulas represent at least two hydrocarbon groups), and at least two of the ester groups are bonded to adjacent carbon atoms on the alicyclic ring: The following compounds (a) to (c): (a) having an alicyclic ring and two or more carboxyl groups,
And an alicyclic polycarboxylic acid or a derivative thereof in which at least two of the carboxyl groups are bonded to adjacent carbon atoms on the alicyclic ring, (b) a compound having two or more hydroxyl groups or a derivative thereof, and (C) A compound obtained by using a compound having one hydroxyl group or a derivative thereof is preferable.

Further, the refrigerator oil composition of the present invention comprises at least one selected from the group consisting of phosphate esters, acidic phosphate esters, amine salts of acidic phosphate esters, chlorinated phosphate esters and phosphite esters. It is preferable to further contain a phosphorus compound and / or an epoxy compound.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail.

The refrigerating machine oil composition of the present invention is characterized in that a phosphorothioate compound is added to a base oil containing an alicyclic polycarboxylic acid ester compound. The cyclic polycarboxylic acid ester compound is an ester of an alicyclic polycarboxylic acid and an alcohol.

The alicyclic polycarboxylic acid is preferably a tetravalent or less polyvalent carboxylic acid,
More preferably, it is a trivalent or less polyvalent carboxylic acid,
Most preferably, it is a divalent dicarboxylic acid. In addition,
In the case of a monovalent alicyclic monocarboxylic acid, the compatibility with the refrigerant and the stability of heat and hydrolysis become insufficient.

A carboxyl group (or an ester group)
Is not particularly limited, but it is preferable that at least two carboxyl groups (or ester groups) are bonded to adjacent carbon atoms on the alicyclic ring. If the carboxyl group (or ester group) is not bonded to adjacent carbon atoms on the alicyclic ring, the resulting refrigerating machine oil tends to have poor heat / hydrolysis stability and lubricity.

Further, any alcohol can be used as the alcohol according to the present invention.
It may be a polyhydric alcohol having at least two hydroxyl groups.

Preferred examples of the alicyclic polycarboxylic acid ester compound according to the present invention include the following 2
Species: [I] alicyclic ring and at least two ester groups represented by the following general formula (1): -COOR (1) (wherein, R represents a hydrocarbon group having 1 to 30 carbon atoms) A compound having at least two of the ester groups bonded to adjacent carbon atoms on the alicyclic ring (hereinafter, referred to as compound [I]); [II] Compounds (a) to (c) below ): (A) having an alicyclic ring and two or more carboxyl groups,
And an alicyclic polycarboxylic acid or a derivative thereof in which at least two of the carboxyl groups are bonded to adjacent carbon atoms on the alicyclic ring, (b) a compound having two or more hydroxyl groups or a derivative thereof, and (C) a compound obtained using a compound having one hydroxyl group or a derivative thereof (hereinafter, referred to as compound [II]).

First, the compound [I] which is the first compound suitable as the alicyclic polycarboxylic acid ester compound according to the present invention will be described.

The alicyclic ring of the compound [I] includes
Examples thereof include a cyclopentane ring, a cyclopentene ring, a cyclohexane ring, a cyclohexene ring, a cycloheptane ring, and a cycloheptene ring, and a cyclohexane ring and a cyclohexene ring are preferred. Furthermore, among these, the cyclohexane ring is more preferable because the viscosity increase is small when used under long-term or severe conditions, and the cyclohexene ring is small in the increase in total acid value when used under long-term or severe conditions. Is more preferable.

The compound [I] has at least two ester groups represented by the above formula (1) together with the above alicyclic ring. When there is only one ester group, the compatibility with the refrigerant and the stability of heat and hydrolysis are insufficient, which is not preferable. On the other hand, the upper limit of the number of ester groups is not particularly limited, but is preferably 4 or less, more preferably 3 or less, and most preferably 2 from the viewpoint of low-temperature fluidity.

In the compound [I], at least two of the ester groups represented by the above formula (1) are
It is necessary that they are bonded to adjacent carbon atoms on the alicyclic ring. When the ester group is not bonded to adjacent carbon atoms on the alicyclic ring, the resulting alicyclic polycarboxylic acid ester compound tends to have insufficient heat / hydrolysis stability and lubricity. It is in.

The configuration of the ester group is not particularly limited, and the orientation of the ester group bonded to adjacent carbon atoms on the alicyclic ring may be either cis or trans. In addition, cis body or tran
The s-isomer may be used alone or as a mixture of both. However, the cis form is preferable from the viewpoint of heat and hydrolysis stability, and the trans form is preferable from the viewpoint of achieving both heat and hydrolysis stability and lubricity. Also,
When a mixture of the cis form and the trans form is used, the molar ratio is preferably 20/80 to 80/20, more preferably 25/75 to 75/25, and further preferably 30.
/ 70 to 70/30. When the molar ratio between the cis-form and the trans-form is within the above range, higher lubricity and higher heat / hydrolysis stability tend to be compatible.

R in the above formula (1) has 1 to 3 carbon atoms.
0, preferably 2 to 24, more preferably 3 to 18 hydrocarbon groups. Examples of the hydrocarbon group include an alkyl group, an alkenyl group, a cycloalkyl group, an alkylcycloalkyl group, an aryl group, an alkylaryl group, and an arylalkyl group. Among them, an alkyl group, a cycloalkyl group and an alkylcycloalkyl group are preferable from the viewpoint of heat and hydrolysis stability.

Such an alkyl group may be a linear or branched one. Specifically, for example, a linear or branched propyl group or a linear Or branched butyl group, straight or branched pentyl group, straight or branched hexyl group, straight or branched heptyl group, straight or branched chain Octyl group, linear or branched nonyl group, linear or branched decyl group, linear or branched undecyl group, linear or branched dodecyl group, linear Or a branched tridecyl group, a linear or branched tetradecyl group,
Examples thereof include a linear or branched pentadecyl group, a linear or branched hexadecyl group, a linear or branched heptadecyl group, and a linear or branched octadecyl group.

Among these alkyl groups, the linear alkyl group is preferably one having 4 or more carbon atoms from the viewpoint of heat and hydrolysis stability, and preferably 18 or less carbon atom from the viewpoint of refrigerant compatibility. . Further, the branched alkyl group preferably has 3 or more carbon atoms from the viewpoint of heat and hydrolysis stability, and has 18 carbon atoms from the viewpoint of refrigerant compatibility.
The following are preferred.

Examples of the cycloalkyl group include a cyclopentyl group, a cyclohexyl group and a cycloheptyl group, and a cyclohexyl group is preferred from the viewpoint of heat and hydrolysis stability. Further, the alkylcycloalkyl group is a group in which an alkyl group is bonded to a cycloalkyl group, and a group in which an alkyl group is bonded to a cyclohexyl group is preferable from the viewpoint of heat and hydrolysis stability. Further, the alkylcycloalkyl group preferably has a total carbon number of 6 or more from the viewpoint of heat and hydrolysis stability, and preferably has a total carbon number of 10 or less from the viewpoint of refrigerant compatibility and low-temperature fluidity.

The compound [I] uses an alicyclic polycarboxylic acid or a derivative thereof and a monohydric alcohol (ROH; R represents the same definition as R in the above formula (1)) or a derivative thereof. Thus, it can be obtained by a manufacturing method described later. In this case, as the alcohol component, a monohydric alcohol may be used alone, or a mixture of two or more monohydric alcohols may be used. However, there is not enough heat
It is preferable to use a mixture of two or more monohydric alcohols because hydrolysis stability and lubricity are obtained, and further excellent refrigerant compatibility tends to be obtained. The following combinations: (i) carbon Use of a mixture of at least one alcohol selected from the group consisting of aliphatic alcohols of formulas 1 to 5, and (ii) at least one alcohol selected from the group consisting of aliphatic alcohols having 6 to 18 carbon atoms Is more preferred.

When only one type of the alcohol (i) is used, the resulting alicyclic polycarboxylic acid ester compound has poor heat / hydrolysis stability and tends to have insufficient lubricity. It is in. In addition, when only one kind of the alcohol (ii) is used, the obtained alicyclic polycarboxylic acid ester compound tends to have insufficient refrigerant compatibility.

In the alicyclic polycarboxylic acid ester compound obtained using the alcohol components (i) and (ii), R derived from the aliphatic alcohol (i) is an alkyl group having 1 to 5 carbon atoms. R derived from (ii) is an alkyl group having 6 to 18 carbon atoms.

R derived from the aliphatic alcohol (i)
Specific examples include, for example, a methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group, a linear or branched pentyl group, and the like. Among them, an alkyl group having 3 to 5 carbon atoms is preferable from the viewpoint of heat and hydrolysis stability. Further, it may be straight-chain or branched-chain, but from the viewpoint of achieving both lubricity and heat / hydrolysis stability, it is not necessary to use n-butyl or n-pentyl. In terms of compatibility between refrigerant compatibility and heat / hydrolysis stability, chain alkyl groups are
A branched alkyl group such as an o-butyl group and an iso-pentyl group is preferred.

On the other hand, as R derived from the aliphatic alcohol (ii), specifically, for example, a linear or branched hexyl group, a linear or branched heptyl group, a linear Or a branched octyl group, a straight or branched nonyl group, a straight or branched decyl group, a straight or branched undecyl group, a straight or branched dodecyl Group, linear or branched tridecyl group, linear or branched tetradecyl group, linear or branched pentadecyl group, linear or branched hexadecyl group, linear or Examples thereof include a branched heptadecyl group, a linear or branched octadecyl group, and among them, an alkyl group having 6 to 12 carbon atoms is preferable from the viewpoint of refrigerant compatibility, and an alkyl group having 7 to 9 carbon atoms. Is more preferred. Also,
It may be linear or branched, but from the viewpoint of compatibility between lubricity and refrigerant compatibility, n-
A linear alkyl group such as a heptyl group, an n-octyl group, an n-nonyl group, and an n-decyl group is preferable. From the viewpoint of compatibility between refrigerant compatibility and heat / hydrolysis stability, an iso-heptyl group, Preferred are branched alkyl groups such as -ethylhexyl group and 3,5,5-trimethylhexyl group. Further, an alkyl group having more than 18 carbon atoms is not preferred because it tends to be inferior in refrigerant compatibility and low-temperature fluidity.

The compound [I] according to the present invention is preferably an alicyclic polycarboxylic acid ester compound obtained by using the alcohol of the above-mentioned component (i) and the alcohol of the above-mentioned component (ii). Wherein at least one of the ester groups represented by the above formula (1) present in the same molecule is (i)
An ester in which at least one ester group is a group derived from the component, and at least one is a group derived from the component (ii); All the ester groups represented by the above formula (1) and at least two ester groups represented by the above formula (1) present in the same molecule are represented by (i)
i) a mixture with an ester which is a group derived from the component, and a mixture with

As the preferred compound [I] in the present invention, any of the above-mentioned compounds can be used, but it is more preferable that the compound is from the viewpoint of heat and hydrolysis stability.

In the above case, the content ratio of and is not particularly limited, but is preferably 5% by mass or more based on the total amount of and from the viewpoint of heat and hydrolysis stability. The content is more preferably 10% by mass or more, still more preferably 15% by mass or more, and particularly preferably 20% by mass or more.

In the preferred compound [I] of the present invention, the ratio (molar ratio) of R in the above formula (1) to R derived from the alcohol of the component (i) and R derived from the alcohol of the component (ii). Is not particularly limited, but is more preferably in the range of 1/99 to 99/1 from the viewpoint of simultaneously satisfying all of lubricity, heat / hydrolysis stability, and refrigerant compatibility.

Further, from the viewpoint of giving more importance to compatibility,
The ratio (molar ratio) of R derived from the alcohol of component (i) to R derived from the alcohol of component (ii) is 60/40.
９９99/1, preferably 70/30 ／
It is more preferably in the range of 99/1, and 80/20.
Most preferably, it is in the range of ~ 99/1. In addition, from the viewpoint of placing more importance on heat / hydrolysis stability and lubricity, the above ratio is preferably in the range of 1/99 to 60/40, and more preferably in the range of 1/99 to 50/50. Is more preferable, and most preferably in the range of 1/99 to 40/60.

The compound [I] may have one or more hydrocarbon groups bonded to carbon atoms on the alicyclic ring. As such a hydrocarbon group, an alkyl group is preferable, and a methyl group is particularly preferable in terms of compatibility.

The compound [I] according to the present invention has the above-mentioned structure. Such an ester compound is prepared by converting a predetermined acid component and an alcohol component according to a conventional method, preferably using an inert compound such as nitrogen. It is prepared by esterification while heating in a gas atmosphere in the presence of an esterification catalyst or without a catalyst.

The acid component of the compound [I] is cycloalkane polycarboxylic acid, cycloalkene polycarboxylic acid or an acid anhydride thereof, wherein at least two ester groups are adjacent to each other on the alicyclic ring. Those bonded to carbon atoms are mentioned, and these can be used as one kind or as a mixture of two or more kinds. Specifically, 1,2-
Cyclohexanedicarboxylic acid, 4-cyclohexene-
1,2-dicarboxylic acid, 1-cyclohexene-1,2-
Dicarboxylic acid, 3-methyl-1,2-cyclohexanedicarboxylic acid, 4-methyl-1,2-cyclohexanedicarboxylic acid, 3-methyl-4-cyclohexene-1,2-
Dicarboxylic acid, 4-methyl-4-cyclohexene-1,
Examples thereof include 2-dicarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, and acid anhydrides thereof. this house,
From the viewpoint of suppressing an increase in viscosity during use of the prepared ester compound under long-term or severe conditions,
1,2-cyclohexanedicarboxylic acid, 3-methyl-
1,2-cyclohexanedicarboxylic acid, 4-methyl-
Preferred are 1,2-cyclohexanedicarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid and their acid anhydrides. 2-
Cyclohexanedicarboxylic acid is more preferred. On the other hand, from the viewpoint of suppressing an increase in the total acid value during use under long-term or severe conditions, 4-cyclohexene-1,2 is preferred.
-Dicarboxylic acid, 1-cyclohexene-1,2-dicarboxylic acid, 4-methyl-1,2-cyclohexanedicarboxylic acid, 3-methyl-4-cyclohexene-1,2-dicarboxylic acid, 4-methyl-4-cyclohexene- 1,2-
Dicarboxylic acids and their acid anhydrides are preferable, and among them, 4-cyclohexene-1,2-dicarboxylic acid is more preferable because of its excellent compatibility and heat / hydrolysis stability.

The method for producing the above-mentioned alicyclic polycarboxylic acid and its anhydride is not particularly limited, and those obtained by a conventionally known method can be used. Specifically, for example,
4-cyclohexene-1,2-dicarboxylic acid is obtained by converting butadiene and maleic anhydride to 100
The reaction can be obtained at ℃.

The alcohol component of the compound [I] according to the present invention may be a linear alcohol having 3 to 18 carbon atoms, a branched alcohol having 3 to 18 carbon atoms, or a cycloalcohol having 5 to 10 carbon atoms. Alcohol. Specifically, linear or branched propanol (including n-propanol, 1-methylethanol, etc.) and linear or branched butanol (n-butanol, 1-methylpropanol, 2-methyl Propanol, etc.), linear or branched pentanol (n-pentanol, 1-
Methylbutanol, 2-methylbutanol, 3-methylbutanol, etc.), linear or branched hexanol (n-hexanol, 1-methylpentanol,
-Methylpentanol, 3-methylpentanol, etc.), linear or branched heptanol (n-heptanol, 1-methylhexanol, 2-methylhexanol, 3-methylhexanol, 4-methylhexanol, 5 -Methylhexanol, 2,4-dimethylpentanol, etc.), linear or branched octanol (including n-octanol, 2-ethylhexanol, 1-methylheptanol, 2-methylheptanol, etc.) , Linear or branched nonanol (including n-nonanol, 1-methyloctanol, 3,5,5-trimethylhexanol, 1- (2′-methylpropyl) -3-methylbutanol, etc.), linear Or branched decanol (including n-decanol, iso-decanol, etc.), linear or branched (Including n-undecanol, etc.), linear or branched dodecanol (including n-dodecanol, iso-dodecanol, etc.), linear or branched tridecanol, linear or branched chain (Including n-tetradecanol, iso-tetradecanol, etc.), linear or branched pentadecanol, linear or branched hexadecanol (n-hexadecanol) , Iso-hexadecanol, etc.), linear or branched heptadecanol, linear or branched octadecanol (including n-octadecanol, iso-octadecanol, etc.) , Cyclohexanol, methylcyclohexanol, dimethylcyclohexanol and the like.

In the compound [I] according to the present invention,
As mentioned above, among these alcohol components, (i)
At least one alcohol selected from the group consisting of aliphatic alcohols having 1 to 5 carbon atoms, and (ii) 6 to 5 carbon atoms.
It is preferable to use at least one alcohol selected from the group consisting of 18 aliphatic alcohols. Examples of the alcohol as the component (i) include a linear alcohol having 1 to 5 carbon atoms or a branched alcohol having 3 to 5 carbon atoms. Specifically, for example, methanol, ethanol, n-propanol, n-butanol, n-pentanol, iso-propanol, iso-butanol, sec-butanol, iso-pentanol and the like, among which lubricity and From the viewpoint of compatibility between heat and hydrolysis stability, linear alcohols such as n-butanol and n-pentanol are preferable.
From the viewpoint of compatibility of hydrolysis stability, branched alcohols such as iso-butanol and iso-pentanol are preferred.

On the other hand, the alcohol as the component (ii) may be a straight-chain alcohol having 6 to 18 carbon atoms or a 6-carbon alcohol.
To 18 branched chain alcohols. Specifically, for example, n-hexanol, n-heptanol, n-
Octanol, n-nonanol, n-decanol, n-
Undecanol, n-dodecanol, n-tetradecanol, n-hexadecanol, n-octadecanol,
iso-hexanol, 2-methylhexanol, 1-
Methylheptanol, 2-methylheptanol, iso
-Heptanol, 2-ethylhexanol, 2-octanol, iso-octanol, 3,5,5-trimethylhexanol, iso-decanol, iso-tetradecanol, iso-hexadecanol, iso-octadecanol, 2,6 -Dimethyl-4-heptanol and the like, from the viewpoint of compatibility between lubricity and refrigerant compatibility, n-heptanol, n-octanol, n-nonanol, linear alcohols such as n-decanol are preferred,
From the viewpoint of compatibility between refrigerant compatibility and heat and hydrolysis stability, iso-heptanol, 2-ethylhexanol,
Branched alcohols such as 3,5,5-trimethylhexanol are preferred.

In conducting the esterification reaction using the above-mentioned acid component and alcohol component, the alcohol component is used in an amount of usually 1.0 to 1.5 equivalents, preferably 1.05 to 1. Two equivalents are used.

Further, instead of the acid component and the alcohol component, a compound according to the present invention is obtained by a transesterification reaction using a lower alcohol ester of the acid component and / or an acetate ester or a propionate ester of the alcohol component [ I] can also be obtained.

Examples of the esterification catalyst used in the above esterification reaction include Lewis acids such as aluminum derivatives, tin derivatives and titanium derivatives; alkali metal salts such as sodium alkoxide and potassium alkoxide; Examples thereof include sulfonic acids such as toluenesulfonic acid, methanesulfonic acid, and sulfuric acid.
Among them, Lewis acids such as aluminum derivatives, tin derivatives, and titanium derivatives are preferable in consideration of the effect on the thermal and hydrolytic stability of the obtained compound [I], and tin derivatives are particularly preferable in terms of reaction efficiency. preferable.
The amount of the esterification catalyst used is, for example, 0.1 to 1 with respect to the total amount of the raw material acid component and alcohol component.
% By mass.

The reaction temperature in the above esterification reaction is, for example, 150 to 230 ° C., usually 3 to 3 ° C.
The reaction is completed in 0 hours. After completion of the esterification reaction, the excess raw material is distilled off under reduced pressure or normal pressure, and subsequently, a conventional purification method, for example, liquid-liquid extraction, vacuum distillation,
A purified ester compound [I] can be obtained by adsorption purification treatment such as activated carbon treatment.

Next, the compound [II] which is the second compound suitable as the alicyclic polycarboxylic acid ester compound according to the present invention will be described.

The (a) alicyclic polycarboxylic acid or a derivative thereof used as an acid component in the compound [II] according to the present invention needs to have an alicyclic ring and two or more carboxyl groups. (Hereinafter, generically referred to as compound (a) including derivatives of alicyclic polycarboxylic acids). When there is only one carboxyl group, the compatibility with the refrigerant and the heat and heat
Insufficient hydrolytic stability. The upper limit of the number of carboxyl groups is not particularly limited, but is preferably 4 or less, more preferably 3 or less, and most preferably 2. If the number of carboxyl groups exceeds the upper limit, the resulting alicyclic polycarboxylic acid ester compound tends to have insufficient low-temperature fluidity.

Further, at least two of the carboxyl groups of the compound (a) according to the present invention must be bonded to mutually adjacent carbon atoms on the alicyclic ring. When the compound does not have two carboxyl groups bonded to adjacent carbon atoms on the alicyclic ring, the resulting alicyclic polycarboxylic acid ester compound has insufficient heat and hydrolysis stability. There is a tendency.

When the compound (a) according to the present invention is an alicyclic polycarboxylic acid, the configuration of the carboxyl group is not particularly limited, and the carboxyl group bonded to adjacent carbon atoms on the alicyclic ring is not limited. Group orientation is cis, t
Any of the rans bodies may be used. In addition, the cis form or trans form may be used alone or as a mixture of both. However, the cis form is preferable from the viewpoint of heat and hydrolysis stability, and the trans form is preferable from the viewpoint of achieving both heat and hydrolysis stability and lubricity. When a mixture of the cis form and the trans form is used, the molar ratio thereof is preferably 20/80 to 80/2.
0, more preferably 25/75 to 75/25, and still more preferably 30/70 to 70/30. cis body and t
When the molar ratio with the ran form is in the above range, higher lubricity and higher heat / hydrolysis stability tend to be compatible.

The alicyclic polycarboxylic acid according to the present invention includes, among cycloalkane polycarboxylic acids, cycloalkene polycarboxylic acids and the like, at least two carboxyl groups having carbon atoms adjacent to each other on the alicyclic ring. And these may be used alone or in combination.
You may use as a mixture of 2 or more types. As the alicyclic polycarboxylic acid having such a structure, specifically,
1,2-cyclohexanedicarboxylic acid, 4-cyclohexene-1,2-dicarboxylic acid, 1-cyclohexene-
1,2-dicarboxylic acid, 3-methyl-1,2-cyclohexanedicarboxylic acid, 4-methyl-1,2-cyclohexanedicarboxylic acid, 3-methyl-4-cyclohexene-
Disclosed are 1,2-dicarboxylic acid, 4-methyl-4-cyclohexene-1,2-dicarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid. Among these, from the viewpoint of suppressing an increase in viscosity of the obtained alicyclic polycarboxylic acid ester compound when used under long-term or severe conditions, 1,2-cyclohexanedicarboxylic acid, 3-methyl-1, 2-cyclohexanedicarboxylic acid, 4-methyl-1,2-cyclohexanedicarboxylic acid, 1,2,4-
Cyclohexanetricarboxylic acid and 1,2,4,5-cyclohexanetetracarboxylic acid are preferred. On the other hand, from the viewpoint of suppressing an increase in the total acid value when used under long-term or severe conditions, 4-cyclohexene-1,2 is preferred. -Dicarboxylic acid, 1-cyclohexene-1,2-dicarboxylic acid, 4-methyl-1,2-cyclohexanedicarboxylic acid, 3-methyl-4-cyclohexene-1,2-dicarboxylic acid, 4-methyl-4-cyclohexene- 1,2-dicarboxylic acid is preferred.

The compound (a) according to the present invention may be a derivative of an alicyclic polycarboxylic acid such as an acid anhydride, an ester or an acid halide. Examples of the alicyclic polycarboxylic acid derivative used in the present invention include acid anhydrides, esters, acid halides, and the like of the compounds exemplified in the description of the alicyclic polycarboxylic acid.

The method for producing these alicyclic polycarboxylic acids and derivatives thereof is not particularly limited, and those obtained by any method can be used. Specifically, for example, 4-cyclohexene-1,2-dicarboxylic acid can be obtained by reacting butadiene and maleic anhydride at 100 ° C. in a benzene solvent.

The compound (b), which is one of the alcohol components used in the compound [II] of the present invention, needs to have two or more hydroxyl groups.
Examples of such compound (b) include polyhydric alcohols, polyhydric phenols, polyhydric amino alcohols, condensates thereof, and the like, and compounds in which the hydroxyl groups of these compounds are esterified with a lower carboxylic acid such as acetic acid. (Hereinafter, generically referred to as compound (b) including derivatives of compounds having two or more hydroxyl groups). Among these, it is preferable to use a polyhydric alcohol or a condensate thereof, because the compatibility with the refrigerant, the electrical insulation, and the thermal stability tend to be further improved.

The polyhydric alcohol suitably used in the compound [II] according to the present invention preferably has 2 to 2 carbon atoms.
10, more preferably 2 to 8, and the molecule may contain an ether bond. Specific examples of such polyhydric alcohols include, for example, ethylene glycol, propylene glycol, butylene glycol, 1,3-butanediol, 1,4-butanediol, glycerin, neopentyl glycol, trimethylolethane, and trimethylol. Propane, trimethylolbutapan, pentaerythritol, 1,3,5-pentanetriol, sorbitol, sorbitan, isosorbide, sorbitol glycerin condensate, adonitol,
Arabitol, xylitol, mannitol, xylose, arabinose, ribose, rhamnose, glucose, fructose, galactose, mannose, sorbose, cellobiose, maltose, isomaltose, trehalose, sucrose, raffinose, gentianose, melezitose, methylglucoside, and their partial ethers And the like.

The polyhydric alcohol condensate suitably used in the compound [II] according to the present invention is preferably obtained by condensing a polyhydric alcohol having 2 to 10 carbon atoms, more preferably 2 to 8 carbon atoms. It is obtained. From the viewpoints of electrical properties and ease of production, the degree of condensation of the polyhydric alcohol condensate is preferably 2 to 10, and more preferably 2 to 5
It is. As the polyhydric alcohol condensate having such a structure, specifically, for example, diethylene glycol,
Triethylene glycol, tetraethylene glycol,
Pentaethylene glycol, dipropylene glycol,
Tripropylene glycol, tetrapropylene glycol, pentapropylene glycol, dibutylene glycol, tributylene glycol, tetrabutylene glycol, pentabutylene glycol, diglycerin, triglycerin, tetraglycerin, pentaglycerin, di (neopentyl glycol), tri (neoprene) Pentyl glycol), tetra (neopentyl glycol), penta (neopentyl glycol), di (trimethylolethane), tri (trimethylolethane), tetra (trimethylolethane), penta (trimethylolethane),
Di (trimethylolpropane), tri (trimethylolpropane), tetra (trimethylolpropane), penta (trimethylolpropane), di (trimethylolbutane), tri (trimethylolbutane), tetra (trimethylolbutane), penta (Trimethylolbutane), di (pentaerythritol), tri (pentaerythritol), tetra (pentaerythritol), penta (pentaerythritol) and the like.

Compound (b) used as one of the alcohol components in compound [II] of the present invention
May be a derivative whose hydroxyl group is esterified with a lower carboxylic acid as described above. As such a derivative, an acetate or propionate of the compound exemplified in the description of the polyhydric alcohol and the polyhydric alcohol condensate is preferably used.

The compound (c) which is the other of the alcohol components used in the compound [II] according to the present invention needs to have one hydroxyl group. Examples of such a compound (c) include monohydric alcohols, monohydric phenols, monohydric amino alcohols, and compounds in which these hydroxyl groups are esterified with a lower carboxylic acid such as acetic acid (hereinafter, including derivatives). (Compound (c)).

Among these, it is preferable to use a linear monohydric alcohol having 3 to 18 carbon atoms, a branched monohydric alcohol having 3 to 18 carbon atoms, or a monohydric cycloalcohol having 5 to 10 carbon atoms. . Specific examples of such a monohydric alcohol include linear or branched propanol (including n-propanol and 1-methylethanol), and linear or branched butanol (n-butanol). , 1-methylpropanol, 2-methylpropanol, etc.), linear or branched pentanol (n-
Pentanol, 1-methylbutanol, 2-methylbutanol, 3-methylbutanol, etc.), linear or branched hexanol (n-hexanol, 1-methylpentanol, 2-methylpentanol, Methylpentanol, etc.), linear or branched heptanol (n-heptanol, 1-methylhexanol,
2-methylhexanol, 3-methylhexanol, 4
-Methylhexanol, 5-methylhexanol, 2,
4-dimethylpentanol, etc.), linear or branched octanol (including n-octanol, 2-ethylhexanol, 1-methylheptanol, 2-methylheptanol, etc.), linear or branched Chain nonanol (n-nonanol, 1-methyloctanol, 3,5,
5-trimethylhexanol, 1- (2-methylpropyl) -3-methylbutanol, etc.), linear or branched decanol (including n-decanol, iso-decanol, etc.), linear or branched Linear undecanol (including n-undecanol, etc.), linear or branched dodecanol (including n-dodecanol, iso-dodecanol, etc.), linear or branched tridecanol, linear or branched Linear tetradecanol (including n-tetradecanol, iso-tetradecanol, etc.),
Linear or branched pentadecanol, linear or branched hexadecanol (n-hexadecanol, i
so-hexadecanol, etc.), linear or branched heptadecanol, linear or branched octadecanol (including n-octadecanol, iso-octadecanol, etc.), Cyclohexanol, methylcyclohexanol, dimethylcyclohexanol and the like can be mentioned.

Further, as compound (c), one kind of compound may be used alone, or two or more kinds of compounds may be used in combination. However, the use of a mixture of two or more compounds is preferred because sufficient thermal / hydrolytic stability and lubricity, and further excellent refrigerant compatibility tend to be obtained, and the following combinations are preferred: (c-I ) At least one monohydric alcohol selected from the group consisting of aliphatic monohydric alcohols having 1 to 5 carbon atoms, and (c-II) at least one selected from the group consisting of aliphatic monohydric alcohols having 6 to 18 carbon atoms. It is more preferable to use a mixture comprising one kind of monohydric alcohol.

The alcohol 1 of the above component (c-I)
When only the seed is used, the resulting compound tends to have poor heat / hydrolysis stability and insufficient lubricity. In addition, when only one kind of the alcohol (c-II) is used, the obtained compound tends to have insufficient refrigerant compatibility.

The alcohol of the component (c-I) is an aliphatic monohydric alcohol having 1 to 5 carbon atoms, and specifically, for example, a linear alcohol having 1 to 5 carbon atoms or 3 alcohols.
To 5, and more specifically, for example, methanol, ethanol, n-propanol, n-butanol, n-pentanol, iso-propanol, iso-butanol, sec-butanol,
iso-pentanol and the like. Among them, alcohols having 3 to 5 carbon atoms are preferable from the viewpoint of heat and hydrolysis stability. In addition, although it may be linear or branched, n-butanol and n-butanol are preferred from the viewpoint of compatibility between heat / hydrolysis stability and lubricity.
Linear alcohols such as pentanol are preferable, and from the viewpoint of compatibility between refrigerant compatibility and heat / hydrolysis stability, i.
Branched alcohols such as so-butanol and iso-pentanol are preferred.

On the other hand, the alcohol of the component (c-II) is an aliphatic monohydric alcohol having 6 to 18 carbon atoms. ~ 18 branched-chain alcohols,
More specifically, for example, n-hexanol, n-heptanol, n-octanol, n-nonanol, n-decanol, n-undecanol, n-dodecanol, n-
Tetradecanol, n-hexadecanol, n-octadecanol, iso-hexanol, 2-methylhexanol, 1-methylheptanol, 2-methylheptanol, iso-heptanol, 2-ethylhexanol, 2-octanol, iso-octanol, 3,
5,5-trimethylhexanol, iso-decanol, iso-tetradecanol, iso-hexadecanol, iso-octadecanol, 2,6-dimethyl-
4-heptanol and the like. Among them, alcohols having 6 to 12 carbon atoms are preferable from the viewpoint of refrigerant compatibility, and alcohols having 7 to 9 carbon atoms are more preferable. Moreover, although it may be linear or branched, it may be n-heptanol, n-octanol, n-nonanol, n-heptanol from the viewpoint of compatibility between lubricity and refrigerant compatibility. Linear alcohols such as decanol are preferred,
From the viewpoint of compatibility between refrigerant compatibility and heat / hydrolysis stability, iso-heptanol, 2-ethylhexanol,
Branched alcohols such as 3,5,5-trimethylhexanol are preferred. Alcohols having more than 18 carbon atoms are not preferred because they tend to have poor refrigerant compatibility and low-temperature fluidity.

When the above components (cI) and (c-II) are used in combination, the molar ratio of the components (cI) and (c-II) is not particularly limited, but lubricity, heat and Since the hydrolysis stability and the compatibility with the refrigerant tend to be satisfied at the same time, the ratio is preferably in the range of 1:99 to 99: 1. In addition, from the viewpoint of placing more emphasis on refrigerant compatibility, the above ratio is preferably in the range of 60:40 to 99: 1, more preferably in the range of 70:30 to 99: 1, and more preferably 80:40 to 99: 1. Most preferably, it is in the range of 20-99: 1. Furthermore, from the viewpoint of placing more importance on heat / hydrolysis stability and lubricity, the above ratio is 1:
It is preferably in the range of 99-60: 40, 1: 9
It is more preferably in the range of 9 to 50:50, and 1:
Most preferably, it is in the range of 99 to 40:60.

The compound (c) used as an alcohol component in the compound [II] according to the present invention may be a derivative in which a hydroxyl group is esterified with a lower carboxylic acid. As such a derivative, an acetate ester, a propionate ester, or the like of the compound exemplified in the description of the monohydric alcohol is preferably used.

Here, in the compound [II] according to the present invention, the following compounds (a ′), (b ′) and (c ′) are used as the compounds (a), (b) and (c): ') 1,2-cyclohexanedicarboxylic acid, 4-cyclohexene-1,2-dicarboxylic acid, and one selected from the group consisting of acid anhydrides, esters and acid halides thereof, (b') ethylene glycol and propylene glycol , Butylene glycol, glycerin, neopentyl glycol, diethylene glycol, dipropylene glycol, dibutylene glycol, diglycerin,
One selected from the group consisting of dineopentyl glycol and esterified products thereof, and (c ′) n-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, n-nonanol, n −
Decanol, iso-butanol, iso-pentanol, iso-hexanol, iso-heptanol, 2
-Ethylhexanol, 3,5,5-trimethylhexanol, a mixed alcohol of n-butanol and n-hexanol, a mixed alcohol of n-butanol and n-heptanol, a mixed alcohol of n-butanol and n-octanol, n -Mixed alcohol of butanol and n-nonanol, mixed alcohol of n-butanol and n-decanol, mixed alcohol of n-butanol and iso-hexanol, mixed alcohol of n-butanol and iso-heptanol, n-butanol Mixed alcohol of n-butanol and 3,5,5-trimethylhexanol, mixed alcohol of iso-butanol and n-hexanol, mixed alcohol of iso-butanol and n-heptanol , so- mixed alcohols of butanol and n- octanol, iso- butanol and mixed alcohols with n- nonanol, iso- butanol and n-
Mixed alcohol with decanol, mixed alcohol with iso-butanol and iso-hexanol, mixed alcohol with iso-butanol and iso-heptanol,
Mixed alcohol of iso-butanol and 2-ethylhexanol, mixed alcohol of iso-butanol and 3,5,5-trimethylhexanol, mixed alcohol of n-pentanol and n-hexanol, n-pentanol and n- Mixed alcohol with heptanol, mixed alcohol with n-pentanol and n-octanol, n
A mixed alcohol of pentanol and n-nonanol,
Mixed alcohol of n-pentanol and n-decanol, mixed alcohol of n-pentanol and iso-hexanol, mixed alcohol of n-pentanol and iso-heptanol, mixed alcohol of n-pentanol and 2-ethylhexanol Mixed alcohol, mixed alcohol of n-pentanol and 3,5,5-trimethylhexanol, mixed alcohol of iso-pentanol and n-hexanol, mixed alcohol of iso-pentanol and n-heptanol, iso-pen Mixed alcohol of tertanol and n-octanol, mixed alcohol of iso-pentanol and n-nonanol, mixed alcohol of iso-pentanol and n-decanol, mixed alcohol of iso-pentanol and iso-hexanol, iso -Pentano A mixed alcohol of iso-pentanol and 2-ethylhexanol, a mixed alcohol of iso-pentanol and 3,5,5-trimethylhexanol, and esterified products thereof. It is particularly preferable to use one selected one in combination.

In carrying out the esterification reaction using the above-mentioned compounds (a) to (c), the total amount of the compound (b) and the compound (c), which are alcohols, is expressed by (a) alicyclic polyvalent carboxylic acid. It is usually used in an amount of 1.0 to 1.5 equivalents, preferably 1.05 to 1.2 equivalents, per equivalent of the acid or its anhydride.

The molar ratio of the compound (b) to the compound (c) is not particularly limited, but can simultaneously satisfy all of lubricity, heat / hydrolysis stability, and refrigerant compatibility. Due to the tendency, it is preferably in the range of 1:99 to 99: 1. Further, from the viewpoint of giving more importance to compatibility, the above ratio is preferably in the range of 1:99 to 80:20, more preferably in the range of 5:95 to 70:30, and more preferably 10:90. Most preferably, it is in the range of 60:40.

The alicyclic polycarboxylic acid ester compound (II) according to the present invention is preferably prepared by combining the acid component of (a) with the alcohol component of (b) and (c) according to a conventional method. It is prepared by esterification while heating in an inert gas atmosphere such as nitrogen, in the presence of an esterification catalyst or in the absence of a catalyst.

When the lower alcohol ester of the alicyclic polycarboxylic acid is used as the compound (a), or when the acetic acid ester or propionate of the alcohol is used as the compound (b) or (c), And the compound [I] of the present invention by transesterification
I] is also possible.

Examples of the esterification catalyst used in the above esterification reaction include Lewis acids such as aluminum derivatives, tin derivatives and titanium derivatives; alkali metal salts such as sodium alkoxide and potassium alkoxide; Examples thereof include sulfonic acids such as toluenesulfonic acid, methanesulfonic acid, and sulfuric acid.
Among them, Lewis acids such as aluminum derivatives, tin derivatives, and titanium derivatives are preferable in consideration of the influence on the heat and hydrolysis stability of the obtained compound [II], and tin derivatives are particularly preferable in terms of reaction efficiency. preferable.
The amount of the esterification catalyst used is, for example, 0.1 to the total amount of the acid component and the alcohol component as the raw materials.
About 1% by mass.

The reaction temperature in the above esterification reaction is, for example, 150 to 230 ° C., usually 3 to 3 ° C.
The reaction is completed in 0 hours. After completion of the esterification reaction, the excess raw material is distilled off under reduced pressure or normal pressure, and subsequently, a conventional purification method, for example, liquid-liquid extraction, vacuum distillation,
A purified ester compound [II] can be obtained by adsorption purification treatment such as activated carbon treatment.

In the above esterification reaction, for example,
When the polycarboxylic acid used as the compound (a) or the derivative thereof has two carboxyl groups and the compound used as the compound (b) has two hydroxyl groups, the reaction product is as follows: Usually, the following formula (A)
(E): R ² —X—R ¹ —X—R ² (A) R ² —X—R ¹ —X—R ¹ —X—R ² (B)

[0075]

Embedded image

[0076]

Embedded image

R ² —X—R ² (E) (wherein, X represents an alicyclic dicarboxylic acid residue derived from compound (a), and R ¹ represents two alicyclic dicarboxylic acid residues derived from compound (b) R ² represents a residue of a compound having one hydroxyl group derived from the compound (c), and R ² represents a residue of a compound having a hydroxyl group.

The alicyclic dicarboxylic acid residue represented by X in the above formulas (A) to (E) is a cyclopentane ring, cyclopentene ring, cyclohexane ring, cyclohexene ring,
It is a group in which a carboxyl group is bonded to adjacent carbon atoms on an alicyclic ring such as a cycloheptane ring and a cycloheptene ring. As such alicyclic dicarboxylic acid residues,
Groups having a cyclohexane ring and a cyclohexene ring are preferred. Further, among these, a group having a cyclohexane ring is more preferable because the viscosity increase tends to be small during use under long-term or severe conditions, and a group having a cyclohexene ring is more preferable when used under long-term or severe conditions. Is more preferable since the increase in the total acid value tends to be small.

The group represented by R ¹ in the above formulas (A) to (E) is a residue obtained by removing a hydroxyl group from a compound having two hydroxyl groups used as the compound (b).

When a dihydric alcohol is used as the compound (b), R ¹ may contain an ether bond, but preferably has 2 to 10 carbon atoms, more preferably 2 to 8 carbon atoms. . Specific examples of such R ¹ include, for example, ethylene glycol, propylene glycol, butylene glycol, 1,3-butanediol,
Residues obtained by removing hydroxyl groups from compounds such as 1,4-butanediol and neopentyl glycol can be mentioned.

When a condensate of a dihydric alcohol is used as the compound (b), R ¹ has a carbon number of 2 to 10 (more preferably 2 to 8) and a condensation degree of 2 to 10 (more preferably 2 to 10).
It is preferably a residue of the condensate of (5). Specific examples of such R ¹ include, for example, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, pentapropylene glycol, dibutylene glycol, trifluorobutylene Residues obtained by removing hydroxyl groups from compounds such as glycol, tetrabutylene glycol, pentabutylene glycol, di (neopentyl glycol), tri (neopentyl glycol), tetra (neopentyl glycol), and penta (neopentyl glycol) are exemplified. .

The group represented by R ² in the above formulas (A) to (E) is a residue obtained by removing the hydroxyl group from the compound having one hydroxyl group used as the compound (c). R ² preferably has 1 to 30 carbon atoms, more preferably 2 to 24 carbon atoms, and even more preferably 3 to 18 carbon atoms. As such R ² , an alkyl group, an alkenyl group, a cycloalkyl group, an alkylcycloalkyl group,
Examples include an aryl group, an alkylaryl group, an arylalkyl group, and the like. Among these, an alkyl group, a cycloalkyl group or an alkylcycloalkyl group is preferable from the viewpoint of heat and hydrolysis stability.

Among the groups represented by R ² , the alkyl group may be linear or branched. As the alkyl group having 3 to 18 carbon atoms, specifically, for example, a linear or branched propyl group, a linear or branched butyl group, a linear or branched pentyl group, Straight or branched hexyl group, straight or branched heptyl group, straight or branched octyl group,
Straight or branched nonyl group, straight or branched decyl group, straight or branched undecyl group, straight or branched dodecyl group, straight or branched chain Tridecyl group, linear or branched tetradecyl group, linear or branched pentadecyl group, linear or branched hexadecyl group, linear or branched heptadecyl group, A chain or branched octadecyl group may, for example, be mentioned.

Among these alkyl groups, linear alkyl groups are preferably those having 4 or more carbon atoms from the viewpoint of heat and hydrolysis stability, and those having 18 carbon atoms or less from the viewpoint of refrigerant compatibility. preferable. Further, the branched alkyl group has 3 carbon atoms from the viewpoint of heat and hydrolysis stability.
The above is preferable, and the number of carbon atoms is 1 from the viewpoint of refrigerant compatibility.
8 or less are preferred.

Among the groups represented by R ² , examples of the cycloalkyl group include a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group, and a cyclohexyl group is preferable from the viewpoint of heat and hydrolysis stability. . Further, the alkylcycloalkyl group is a group in which an alkyl group is bonded to a cycloalkyl group, and a group in which an alkyl group is bonded to a cyclohexyl group is preferable from the viewpoint of heat and hydrolysis stability. Further, the alkylcycloalkyl group has a total carbon number of 6 from the viewpoint of heat and hydrolysis stability.
Those having the total number of carbon atoms of 10 or less are preferred from the viewpoint of refrigerant compatibility and low-temperature fluidity.

When a mixed alcohol of the above-mentioned monohydric alcohols (cI) and (c-II) is used as the compound (c), R ² in the resulting compounds (A) to (E) is used.
Among them, the alkyl group derived from the component (c-I) has 1 carbon atom.
To 5 alkyl groups, and preferably an alkyl group having 3 to 5 carbon atoms from the viewpoint of heat and hydrolysis stability.

The alkyl group having 1 to 5 carbon atoms derived from the component (cI) may be linear or branched, but from the viewpoint of lubricity. A linear alkyl group is preferably a branched alkyl group from the viewpoint of refrigerant compatibility and heat / hydrolysis stability. As such an alkyl group, specifically, for example, a methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group, a linear or branched And a pentyl group. Among them, n-butyl group and n-butyl group are preferred from the viewpoint of achieving both heat / hydrolysis stability and lubricity.
-Pentyl group is preferable, and iso-butyl group, is is preferable from the viewpoint of compatibility between refrigerant compatibility and heat / hydrolysis stability.
An o-pentyl group is preferred.

On the other hand, R ² in the above formulas (A) to (E)
Among them, the alkyl group derived from the component (c-II) is an alkyl group having 6 to 18 carbon atoms, but from the viewpoint of compatibility, an alkyl group having 6 to 12 carbon atoms is preferable, and an alkyl group having 7 to 9 carbon atoms
Is more preferred. The alkyl group having 6 to 18 carbon atoms may be linear or branched, but from the viewpoint of lubricity, the linear alkyl group is compatible with heat and heat. From the viewpoint of hydrolysis stability, a branched alkyl group is preferable. In addition, carbon number is 1
An alkyl group exceeding 8 is not preferred because it tends to be inferior in refrigerant compatibility and low-temperature fluidity.

Examples of the alkyl group having 6 to 18 carbon atoms derived from the component (c-II) include, for example, a linear or branched hexyl group and a linear or branched hexyl group. Heptyl group, linear or branched octyl group, linear or branched nonyl group, linear or branched decyl group, linear or branched undecyl group, linear Or a branched dodecyl group, a straight or branched tridecyl group, a straight or branched tetradecyl group, a straight or branched pentadecyl group, a straight or branched hexadecyl Group, a linear or branched heptadecyl group, a linear or branched octadecyl group, and the like. An n-nonyl group and an n-decyl group are preferred, and refrigerant compatibility From the standpoint of thermal and hydrolytic stability of incompatible iso- heptyl, 2-ethylhexyl, 3,5,5-trimethyl-hexyl group are preferable.

Further, the compound (c) is a compound (cI)
Of alcohol and alcohol of component (c-II)
If present, the conversion represented by the above formulas (A), (B) and (E)
The compounds are respectively represented by the following: Two general formulas R present in the same molecule^TwoRepresented by
One of the alkyl groups is a group derived from the component (c-I).
And the other ester is a group derived from the component (c-II).
, Two general formulas R present in the same molecule^TwoRepresented by
D. Wherein both ester groups are groups derived from the component (c-I);
And two general formulas R in the same molecule ^TwoIn table
Groups in which both the ester groups are derived from the component (c-II)
A mixture with an ester, and a mixture with an ester.

In the compound [II] of the present invention,
Although any of the above-mentioned embodiments can be used, it is preferable from the viewpoint of heat and hydrolysis stability.

In the above case, the content ratio of and is not particularly limited, but from the viewpoint of heat and hydrolysis stability, may be 5% by mass or more based on the total amount of and. The content is more preferably 10% by mass or more, even more preferably 15% by mass or more, and particularly preferably 20% by mass or more.

[0093] Further, the above formula (A), (B), of R ² of (E), R ² derived from an alcohol of (c-I) component
And although (c-II) ratio of R ² derived from the alcohol component (molar ratio) is not particularly limited, lubricity,
Since there is a tendency that all of the heat / hydrolysis stability and the refrigerant compatibility can be satisfied at the same time, 1:99 to 99:
It is preferably in the range of 1. Furthermore, from the viewpoint of placing more emphasis on refrigerant compatibility, the above ratio is 60:40 to
It is preferably in the range of 99: 1, 70: 30-9
It is more preferably in the range of 9: 1, and 80:20 to
Most preferably, it is in the range of 99: 1. In addition, heat
From the viewpoint of emphasizing hydrolysis stability and lubricity,
The ratio is preferably in the range of 1:99 to 60:40, more preferably in the range of 1:99 to 50:50, and most preferably in the range of 1:99 to 40:60. .

In the compound [II] according to the present invention,
When the compounds obtained in the above esterification reaction are those represented by the above formulas (A) to (E), one of the compounds represented by the above formulas (A) to (D) may be used alone. It may be used as a mixture of two or more of the compounds represented by the above formulas (A) to (E). In addition,
The compound [II] according to the present invention has the above formula (A) to (D)
Wherein none of the compounds represented by the formula (E)
When only the compound represented by the formula is used, the balance between the increase in viscosity and the compatibility with the refrigerant tends to be poor, which is not preferable.

When the compound [II] of the present invention is a mixture of two or more of the compounds represented by the above formulas (A) to (E), the content ratio of each compound is arbitrary,
Although not particularly limited, the content based on the total amount of the mixture is preferably as follows from the viewpoint of balance between refrigerant compatibility and various performances and ease of production. (A): 0 to 100 mol%, preferably 1 to 99 mol
1%, more preferably 5 to 95 mol% (B): 0 to 100 mol%, preferably 1 to 90 mol
1%, more preferably 2 to 80 mol% (C): 0 to 100 mol%, preferably 1 to 99 mol
1%, more preferably 5 to 95 mol% (D): 0 to 100 mol%, preferably 1 to 90 mol%
1%, more preferably 2 to 80 mol% (E): 0 to 90 mol%, preferably 1 to 80 mol%
%, More preferably 5 to 75 mol%.

Here, the compound (a) is used as an acid component, the compound (b) is used as an alcohol component,
The esterification reaction using (c) has been described. The compound [II] according to the present invention has a structure in which the acid component in the molecule is derived from the compound (a), and the structure of the alcohol component. Is the above compound (b) and / or
Alternatively, as long as it is derived from (c), its production method is not limited to the above-mentioned method by esterification. For example, an aromatic polycarboxylic acid is obtained by an esterification reaction between an aromatic polycarboxylic acid having two carboxyl groups at carbon atoms adjacent to each other on an aromatic ring and an alcohol of the compounds (b) and (c). The desired alicyclic polycarboxylic acid ester compound can be obtained by obtaining an ester compound and further subjecting the obtained aromatic polycarboxylic acid ester to hydrogenation treatment (hydrogenation treatment).

Further, the compound [I
In I], it is a matter of course that one or more hydrocarbon groups may be bonded to the carbon atom on the alicyclic ring.
As such a hydrocarbon group, an alkyl group is preferable,
Particularly, a methyl group is preferable from the viewpoint of refrigerant compatibility.

The compound [I] and the compound [II] suitable as the alicyclic polycarboxylic acid ester compound according to the present invention have been described above. However, the refrigerating machine oil composition of the present invention has such an alicyclic polycarboxylic acid ester compound. It contains a polyvalent carboxylic acid ester compound as a base oil. The content of the alicyclic polycarboxylic acid ester compound (preferably, the compound [I] and / or the compound [II] described above) in the refrigerator oil composition of the present invention is not particularly limited. From the viewpoint that the excellent various performances of the carboxylic acid ester compound can be further derived, the content is preferably 5% by mass or more, more preferably 10% by mass or more, more preferably 30% by mass or more based on the total amount of the refrigerator oil composition. More preferably, it is most preferably contained by 50% by mass or more.

Further, in the refrigerating machine oil composition of the present invention,
Such an alicyclic polycarboxylic acid ester compound is used as a main base oil. As the base oil of the refrigerator oil composition of the present invention, an alicyclic polycarboxylic acid ester compound alone may be used alone, but in addition to this, the oil defined in the present invention such as a polyol ester or a complex ester may be used. Oxygen-containing synthetic oils such as esters other than the cyclic polycarboxylic acid ester compounds, polyglycols, polyvinyl ethers, ketones, polyphenyl ethers, silicones, polysiloxanes, and perfluoroethers may be used in combination.

The amount of the synthetic oil containing oxygen is not particularly limited. However, from the viewpoint of improving both the thermal efficiency and the stability of heat and hydrolysis of the refrigerating machine oil, 100 parts by weight of the cycloaliphatic polycarboxylic acid ester compound is mixed with 150 parts by weight of the other synthetic oil containing oxygen. It is preferably at most 1 part by weight.
More preferably, the amount is not more than 00 parts by weight.

The refrigerating machine oil composition of the present invention comprises a base oil containing the alicyclic polycarboxylic acid ester compound and a phosphorothionate compound. Hereinafter, the phosphorothionate compound according to the present invention will be described.

As the phosphorothionate compound according to the present invention, the following general formula (2) (R ³ O) ₃ P = S (2) (wherein R ³ is a hydrocarbon group having 1 to 30 carbon atoms or A phosphorothioate compound represented by a hydrogen atom, and each R ³ may be the same or different, except that all R ³ are hydrogen atoms) is preferably used.

R ³ in the general formula (2) represents a hydrocarbon group having 1 to 30 carbon atoms or a hydrogen atom, wherein R ³ is a linear or branched alkyl group having 1 to 24 carbon atoms, A linear or branched alkenyl group having 2 to 24 carbon atoms, a cycloalkyl group or an alkylcycloalkyl group having 5 to 13 carbon atoms, an aryl group or an alkylaryl group having 6 to 18 carbon atoms, 7 to 19 carbon atoms Is preferably any of the above arylalkyl groups.

As the alkyl group having 1 to 24 carbon atoms, which is preferable as R ³ , methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s
an ec-butyl group, a tert-butyl group, a linear or branched pentyl group, a linear or branched hexyl group,
Straight or branched heptyl group, straight or branched octyl group, straight or branched nonyl group, straight or branched decyl group, straight or branched chain Linear undecyl group, linear or branched dodecyl group, linear or branched tridecyl group, linear or branched tetradecyl group, linear or branched pentadecyl group, Linear or branched hexadecyl group, linear or branched heptadecyl group, linear or branched octadecyl group, linear or branched nonadecyl group, linear or branched chain Icosyl group, linear or branched henicosyl group, linear or branched docosyl group, linear or branched tricosyl group, linear or branched tetracosyl group and the like. Can be

Also, R ³ preferably has 2 to 24 carbon atoms.
Examples of the alkenyl group include a vinyl group, a propenyl group, an isopropenyl group, a linear or branched butenyl group, a butadienyl group, a linear or branched pentenyl group, a linear or branched hexenyl group. Group, linear or branched heptenyl group, linear or branched octenyl group,
A linear or branched nonenyl group, a linear or branched decenyl group, a linear or branched undecenyl group,
Straight or branched dodecenyl group, straight or branched tridecenyl group, straight or branched tetradecenyl group, straight or branched pentadecenyl group, straight or branched chain Hexadecenyl group, linear or branched heptadecenyl group, linear or branched octadecenyl group (such as oleyl group), linear or branched nonadecenyl group, linear or branched chain Icosenyl group, a linear or branched henicocenyl group, a linear or branched docosenyl group, a linear or branched tricosenyl group, a linear or branched tetracosenyl group, and the like. Can be

Further, R ³ preferably has 5 to 1 carbon atoms.
Examples of the cycloalkyl group 3 include a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group. Examples of the alkylcycloalkyl group having 5 to 13 carbon atoms which is preferable as R ³ include a methylcyclopentyl group (including all substituted isomers), a dimethylcyclopentyl group (including all substituted isomers), and an ethylcyclopentyl group (including all substituted isomers). ), A linear or branched propylcyclopentyl group (including all substituted isomers), an ethylmethylcyclopentyl group (including all substituted isomers), a trimethylcyclopentyl group (including all substituted isomers) Isomer), diethylcyclopentyl group (including all substituted isomers), ethyldimethylcyclopentyl group (including all substituted isomers), linear or branched propylmethylcyclopentyl group (including all substituted isomers) Propylethylcyclopentyl group (including all substituted isomers) D), di- (linear or branched) propylcyclopentyl group (including all substituted isomers), linear or branched propylethylmethylcyclopentyl group (including all substituted isomers) , Methylcyclohexyl group (including all substituted isomers), dimethylcyclohexyl group (including all substituted isomers), ethylcyclohexyl group (including all substituted isomers), linear or branched propylcyclohexyl Group (including all substituted isomers), ethylmethylcyclohexyl group (including all substituted isomers), trimethylcyclohexyl group (including all substituted isomers), diethylcyclohexyl group (including all substituted isomers) , An ethyldimethylcyclohexyl group (including all substituted isomers), a linear or branched propylmethylcyclohexyl group ( All substituted isomers), linear or branched propylethylcyclohexyl group (including all substituted isomers), di-
(Linear or branched) propylcyclohexyl group (including all substituted isomers), linear or branched propylethylmethylcyclohexyl group (including all substituted isomers), methylcycloheptyl group (Including all substituted isomers), dimethylcycloheptyl group (including all substituted isomers), ethylcycloheptyl group (including all substituted isomers), linear or branched propylcycloheptyl group (Including all substituted isomers), ethylmethylcycloheptyl group (including all substituted isomers), trimethylcycloheptyl group (including all substituted isomers), and diethylcycloheptyl group (including all substituted isomers). ), Ethyldimethylcycloheptyl group (including all substituted isomers), linear or branched propylmethylcycloheptyl group (including all substituted isomers) Propylethylcycloheptyl group (including all substituted isomers), di- (linear or branched) propylcycloheptyl group (including all substituted isomers) Propylethylmethylcycloheptyl group (including all substituted isomers) and the like.

Further, R ³ preferably has 6 to 1 carbon atoms.
Examples of the aryl group 8 include a phenyl group and a naphthyl group. Also, R ³ preferably has 6 to 18 carbon atoms.
Examples of the alkylaryl group include a tolyl group (including all substituted isomers), a xylyl group (including all substituted isomers), an ethylphenyl group (including all substituted isomers),
Linear or branched propylphenyl group (including all substituted isomers), ethylmethylphenyl group (including all substituted isomers), trimethylphenyl group (including all substituted isomers), linear Linear or branched butylphenyl group (including all substituted isomers), linear or branched propylmethylphenyl group (including all substituted isomers),
Diethylphenyl group (including all substituted isomers), ethyldimethylphenyl group (including all substituted isomers), tetramethylphenyl group (including all substituted isomers), linear or branched pentyl Phenyl group (including all substituted isomers), linear or branched hexylphenyl group (including all substituted isomers), linear or branched heptylphenyl group (including all substituted isomers) ), A linear or branched octylphenyl group (including all substituted isomers), a linear or branched nonylphenyl group (including all substituted isomers), a linear or branched Branched decylphenyl group (including all substituted isomers), linear or branched undecylphenyl group (including all substituted isomers), linear or branched dodecylphenyl group (All substituted isomers No), and the like.

Further, R ³ preferably has 7 to 1 carbon atoms.
Examples of the arylalkyl group 9 include a benzyl group, a methylbenzyl group (including all substituted isomers), a dimethylbenzyl group (including all substituted isomers), a phenethyl group, and a methylphenethyl group (including all substituted isomers). Dimethylphenethyl group (including all substituted isomers).

As the phosphorothionate compound according to the present invention, among the compounds represented by the above general formula (2), those in which R ³ is a linear or branched alkyl group having 1 to 18 carbon atoms. And a linear or branched alkenyl group having 2 to 18 carbon atoms, and more preferably an aryl group or an alkylaryl group having 6 to 18 carbon atoms.

Specific examples of the phosphorothionate compound represented by the general formula (2) include tributyl phosphorothionate, tripentyl phosphorothionate, trihexyl phosphorothionate, and the like.
Triheptyl phosphorothionate, trioctyl phosphorothionate, trinonyl phosphorothionate, tridecyl phosphorothionate, triundecyl phosphorothionate, tridodecyl phosphorothionate, tritridecyl phosphorothionate, Tritetradecyl phosphorothionate, tripentadecyl phosphorothionate, trihexadecyl phosphorothionate, triheptadecyl phosphorothionate, trioctadecyl phosphorothionate, trioleyl phosphorothionate, triphenyl phosphorothione Thionate, tricresyl phosphorothionate, trixylenyl phosphorothionate,
Cresyl diphenyl phosphorothionate, xylenyl diphenyl phosphorothionate, tris (n-propylphenyl) phosphorothionate, tris (isopropylphenyl) phosphorothionate, tris (n-butylphenyl) phosphorothionate , Tris (isobutylphenyl) phosphorothionate, tris (s-butylphenyl) phosphorothionate,
Tris (t-butylphenyl) phosphorothionate and the like can be mentioned.

The amount of the phosphorothionate compound used in the present invention is not particularly limited, but from the viewpoint of lubricity, is preferably at least 0.05% by mass, more preferably at least 0.05% by mass, based on the total amount of the composition. It is at least 0.1% by mass, more preferably at least 0.5% by mass. Also,
From the viewpoint of heat and hydrolysis stability, preferably 10% by mass
Or less, more preferably 8% by mass or less, still more preferably 5% by mass or less.

The refrigerating machine oil composition of the present invention is obtained by blending the above-mentioned phosphorothionate compound with a base oil containing the above-mentioned alicyclic polycarboxylic acid ester compound. It contains synthetic oil containing oxygen. The refrigerator oil composition of the present invention can be suitably used in a state in which additives other than the above-mentioned phosphorothionate compound are not added, but may be used in a form in which various additives are blended as necessary. it can. Hereinafter, additives other than the phosphorothionate compound will be described.

In order to further improve the wear resistance and load bearing capacity of the refrigerator oil composition of the present invention, phosphate esters, acidic phosphate esters, amine salts of acidic phosphate esters, chlorinated phosphate esters, It is preferable to mix at least one phosphorus compound selected from the group consisting of acid esters. These phosphorus compounds are esters of phosphoric acid or phosphorous acid with alkanols or polyether alcohols or derivatives thereof.

Specifically, for example, phosphate esters include tributyl phosphate, tripentyl phosphate, trihexyl phosphate, triheptyl phosphate, trioctyl phosphate, trinonyl phosphate, tridecyl phosphate, triundecyl phosphate, and tridodecyl phosphate. , Tritridecyl phosphate, tritetradecyl phosphate, tripentadecyl phosphate, trihexadecyl phosphate, triheptadecyl phosphate, trioctadecyl phosphate, trioleyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl Phosphates, xylenyl diphenyl phosphate, etc .; Butyl acid phosphate,
Monopentyl acid phosphate, monohexyl acid phosphate, monoheptyl acid phosphate, monooctyl acid phosphate, monononyl acid phosphate, monodecyl acid phosphate, monoundecyl acid phosphate, monododecyl acid phosphate, monotridecyl acid tetracarbonate Acid phosphate, monopentadecyl acid phosphate, monohexadecyl acid phosphate, monoheptadecyl acid phosphate, monooctadecyl acid phosphate,
Monooleyl acid phosphate, dibutyl acid phosphate, dipentyl acid phosphate, dihexyl acid phosphate, diheptyl acid phosphate, dioctyl acid phosphate, dinonyl acid phosphate, didecyl acid phosphate, diundecyl acid phosphate, didodecyl acid, didodecyl acid , Ditetradecyl acid phosphate, dipentadecyl acid phosphate, dihexadecyl acid phosphate, diheptadecyl acid phosphate, dioctadecyl acid phosphate, dioleyl acid phosphate, etc .; Ester methylamine, ethylamine, propyl alcohol Butylamine, pentylamine, hexylamine, heptylamine, octylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, trimethylamine, triethylamine, tripropylamine, tripropylamine Salts with amines such as butylamine, tripentylamine, trihexylamine, triheptylamine, and trioctylamine; chlorinated phosphates include tris-dichloropropyl phosphate, tris-chloroethyl phosphate, tris-chlorophenyl phosphate, Polyoxyalkylene bis [di (chloroalkyl)] phosphate; phosphites such as dibutyl phosphite and dipentyl phosphite; , Dihexyl phosphite, diheptyl phosphite, dioctyl phosphite, dinonyl phosphite, didecyl phosphite, diundecyl phosphite, didodecyl phosphite, dioleyl phosphite, diphenyl phosphite, dicresyl phosphite, tributyl phosphite Phyte, tripentyl phosphite, trihexyl phosphite, triheptyl phosphite, trioctyl phosphite, trinonyl phosphite, tridecyl phosphite, triundecyl phosphite, tridodecyl phosphite, trioleyl phosphite, triphenyl Phosphite, tricresyl phosphite, and the like. Also, a mixture of these can be used.

When these phosphorus compounds are blended in the refrigerator oil composition of the present invention, the blending amount is not particularly limited, but is usually based on the total amount of the refrigerator oil composition (based on the total amount of the base oil and all the blended additives). It is desirable to mix the phosphorus compound in such an amount that its content becomes 0.01 to 5.0% by mass, more preferably 0.02 to 3.0% by mass.

Further, in the refrigerating machine oil composition of the present invention,
In order to further improve the thermal and hydrolytic stability, (1) phenyl glycidyl ether type epoxy compound (2) alkyl glycidyl ether type epoxy compound (3) glycidyl ester type epoxy compound (4) allyl oxirane compound (5) alkyl It is preferable to mix at least one epoxy compound selected from the group consisting of oxirane compounds (6) alicyclic epoxy compounds (7) epoxidized fatty acid monoesters and (8) epoxidized vegetable oils.

(1) Examples of the phenylglycidyl ether type epoxy compound include phenylglycidyl ether and alkylphenylglycidyl ether. The alkylphenyl glycidyl ether referred to herein includes those having 1 to 3 alkyl groups having 1 to 13 carbon atoms, among which those having one alkyl group having 4 to 10 carbon atoms, for example, n-butylphenyl glycidyl Ether, i-butylphenyl glycidyl ether,
sec-butylphenyl glycidyl ether, tert
-Butylphenyl glycidyl ether, pentyl phenyl glycidyl ether, hexyl phenyl glycidyl ether, heptyl phenyl glycidyl ether, octyl phenyl glycidyl ether, nonyl phenyl glycidyl ether, decyl phenyl glycidyl ether and the like can be exemplified as preferable ones.

(2) Specific examples of the alkyl glycidyl ether type epoxy compound include decyl glycidyl ether, undecyl glycidyl ether, dodecyl glycidyl ether, tridecyl glycidyl ether, tetradecyl glycidyl ether, 2-ethylhexyl glycidyl ether, neoethyl Pentyl glycol diglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether, 1,6-hexanediol diglycidyl ether,
Examples thereof include sorbitol polyglycidyl ether, polyalkylene glycol monoglycidyl ether, and polyalkylene glycol diglycidyl ether.

(3) As the glycidyl ester type epoxy compound, specifically, the following general formula (3):

[0120]

Embedded image (Wherein, R ⁴ represents a hydrocarbon group having 1 to 18 carbon atoms).

In the above formula (3), R ⁴ represents a hydrocarbon group having 1 to 18 carbon atoms.
C1-C18 alkyl group, C2-C18 alkenyl group, C5-C7 cycloalkyl group, C6-C6
Examples thereof include an alkylcycloalkyl group having 18 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkylaryl group having 7 to 18 carbon atoms, and an arylalkyl group having 7 to 18 carbon atoms. Among them, alkyl groups having 5 to 15 carbon atoms, 2 to 15 carbon atoms
And an alkylphenyl group having an alkyl group having 1 to 4 carbon atoms is preferable.

Among the glycidyl ester type epoxy compounds, preferred are, for example, glycidyl-2,2-dimethyloctanoate, glycidyl benzoate, glycidyl-tert-butyl benzoate, glycidyl acrylate, glycidyl methacrylate and the like. Can be illustrated.

(4) As the allyloxirane compound,
Specifically, 1,2-epoxystyrene, alkyl-
1,2-epoxystyrene and the like can be exemplified.

(5) Specific examples of the alkyloxirane compound include 1,2-epoxybutane, 1,2-epoxypentane, 1,2-epoxyhexane, and 1,2-epoxyhexane.
Epoxy heptane, 1,2-epoxyoctane, 1,2
-Epoxynonane, 1,2-epoxydecane, 1,2-
Epoxy undecane, 1,2-epoxide decan, 1,
2-epoxytridecane, 1,2-epoxytetradecane, 1,2-epoxypentadecane, 1,2-epoxyhexadecane, 1,2-epoxyheptadecane, 1,
Examples thereof include 1,2-epoxyoctadecane, 2-epoxynonadecane, and 1,2-epoxyicosane.

(6) As the alicyclic epoxy compound, the following general formula (4):

[0126]

Embedded image And a compound in which carbon atoms constituting an epoxy group directly constitute an alicyclic ring.

As the alicyclic epoxy compound, specifically, for example, 1,2-epoxycyclohexane, 1,2-epoxy
Epoxycyclopentane, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, bis (3,4-epoxycyclohexylmethyl) adipate, exo-2,3-epoxynorbornane, bis (3,4-epoxy- 6-methylcyclohexylmethyl) adipate, 2- (7-oxabicyclo [4.1.0] hept-3-yl) -spiro (1,3-
Dioxane-5,3 '-[7] oxabicyclo [4.
1.0] heptane, 4- (1'-methylepoxyethyl) -1,2-epoxy-2-methylcyclohexane,
4-epoxyethyl-1,2-epoxycyclohexane and the like can be exemplified.

(7) As the epoxidized fatty acid monoester, specifically, epoxidized C12-20
A fatty acid and an alcohol or phenol having 1 to 8 carbon atoms,
Examples thereof include esters with alkylphenols. Especially the butyl, hexyl, benzyl of epoxy stearic acid,
Cyclohexyl, methoxyethyl, octyl, phenyl and butylphenyl esters are preferably used.

(8) Specific examples of the epoxidized vegetable oil include epoxy compounds of vegetable oils such as soybean oil, linseed oil, and cottonseed oil.

Among these epoxy compounds, heat and hydrolysis stability can be further improved.
Phenyl glycidyl ether type epoxy compounds, glycidyl ester type epoxy compounds, alicyclic epoxy compounds, and epoxidized fatty acid monoesters are preferred, and glycidyl ester type epoxy compounds and alicyclic epoxy compounds are more preferred.

When these epoxy compounds are blended in the refrigerator oil composition of the present invention, the blending amount is not particularly limited, but is usually based on the total amount of the refrigerator oil composition (based on the total amount of the base oil and all the blended additives). It is desirable to mix an epoxy compound in such an amount that its content is 0.1 to 5.0% by mass, more preferably 0.2 to 2.0% by mass.

It is needless to say that two or more of the above phosphorus compounds and epoxy compounds may be used in combination.

In order to further enhance the performance of the refrigerating machine oil composition of the present invention, if necessary, conventionally known refrigerating machine oil additives such as di-tert-butyl-p-cresol, bisphenol A and the like may be used. Phenolic antioxidants, phenyl-α-naphthylamine, N,
Amine-based antioxidants such as N-di (2-naphthyl) -p-phenylenediamine; wear inhibitors such as zinc dithiophosphate; extreme pressure agents such as chlorinated paraffins and sulfur compounds; oily agents such as fatty acids; It is also possible to add additives such as an antifoaming agent such as a system, a metal deactivator such as benzotriazole, a viscosity index improver, a pour point depressant and a detergent / dispersant alone or in combination of several kinds. The total blending amount of these additives is not particularly limited, but is preferably 1 based on the total amount of the refrigerator oil composition (based on the total amount of the base oil and all the blending additives).
0 mass% or less, more preferably 5 mass% or less.

The kinematic viscosity of the refrigerator oil composition of the present invention is not particularly limited, but the kinematic viscosity at 40 ° C. is preferably from 3 to 3.
500mm ² / s, more preferably 4~400mm ² /
s, most preferably from 5 to 300 mm ² / s. The kinematic viscosity at 100 ° C. is preferably 1
~50mm ² / s, more preferably 1.5~40mm ² /
s, most preferably ² to 30 mm ² / s.

The volume resistivity of the refrigerating machine oil composition of the present invention is not particularly limited, but is preferably 1.0 × 10 ¹¹ Ω.
Cm or more, more preferably 1.0 × 10 ¹² Ω · cm or more, and most preferably 1.0 × 10 ¹³ Ω · cm or more. In particular, when used for hermetic refrigerators, high electrical insulation tends to be required. The volume resistivity referred to here is a value [Ω · c at 25 ° C. measured in accordance with JIS C 2101 “Test method for electrical insulating oil”.
m].

The water content of the refrigerating machine oil composition of the present invention is not particularly limited, but is preferably 200 ppm or less, more preferably 100 ppm, based on the total amount of the refrigerating machine oil composition.
pm or less, most preferably 50 ppm or less. Especially when used for hermetic refrigerators, from the viewpoint of heat / hydrolysis stability of oil and its effect on electrical insulation,
It is required that the water content is low.

Further, the total acid value of the refrigerator oil composition of the present invention is not particularly limited, but is preferably 0.1 to prevent corrosion to metals used in the refrigerator or piping.
mgKOH / g or less, more preferably 0.05 mgKO
H / g or less. The total acid value referred to herein is JIS K2501 "Petroleum products and lubricating oil-
Neutralization value test method] [mgKOH /
g].

Further, the ash content of the refrigerating machine oil composition of the present invention is not particularly limited, but is preferably 100 ppm or less in order to enhance the heat and hydrolysis stability of the refrigerating machine oil composition of the present invention and suppress the generation of sludge and the like. , More preferably 50
ppm or less. In the present invention, the ash means a value [ppm] measured in accordance with JIS K 2272 “Test method for ash and sulfated ash of crude oil and petroleum products”.

The refrigerant used in the refrigerator using the refrigerator oil composition of the present invention is HFC refrigerant, fluorine-containing ether-based refrigerant such as perfluoroethers, non-fluorine-containing ether-based refrigerant such as dimethyl ether, and carbon dioxide or hydrocarbon. And the like, and these may be used alone or as a mixture of two or more.

Examples of the HFC refrigerant include hydrofluorocarbons having 1 to 3 carbon atoms, preferably 1 to 2 carbon atoms. Specifically, for example, difluoromethane (HFC-3
2), trifluoromethane (HFC-23), pentafluoroethane (HFC-125), 1,1,2,2-tetrafluoroethane (HFC-134), 1,1,1,
2-tetrafluoroethane (HFC-134a), 1,
1,1-trifluoroethane (HFC-143a),
H such as 1,1-difluoroethane (HFC-152a)
FC, or a mixture of two or more thereof.
These refrigerants are appropriately selected depending on the application and required performance. For example, HFC-32 alone; HFC-23 alone; HF
C-134a alone; HFC-125 alone; HFC-13
4a / HFC-32 = 60-80% by mass / 40-20% by mass of a mixture; HFC-32 / HFC-125 = 40-
70% by mass / 60 to 30% by mass of a mixture; HFC-12
5 / HFC-143a = 40-60 mass% / 60-40
HFC-134a / HFC-32 / H
FC-125 = mixture of 60% by mass / 30% by mass / 10% by mass; HFC-134a / HFC-32 / HFC-1
25 = 40 to 70% by mass / 15 to 35% by mass / 5 to 40
HFC-125 / HFC-134a /
HFC-143a = 35 to 55% by mass / 1 to 15% by mass
/ 40 to 60% by mass of a mixture or the like is a preferred example. More specifically, HFC-134a / HFC
-32 = 70/30% by weight mixture; HFC-32 / H
FC-125 = 60/40% by mass mixture; HFC-3
2 / HFC-125 = 50/50 mass% mixture (R4
10A); HFC-32 / HFC-125 = 45/55
% By weight mixture (R410B); HFC-125 / HF
C-143a = 50/50 mass% mixture (R507
C); HFC-32 / HFC-125 / HFC-134
a = 30/10/60% by mass mixture; HFC-32 /
HFC-125 / HFC-134a = 23/25/52
% By weight of a mixture (R407C); HFC-32 / HFC
-125 / HFC-134a = 25/15/60% by mass
Mixture (R407E); HFC-125 / HFC-1
34a / HFC-143a = 44/4/52% by mass of a mixture (R404A). Natural refrigerants include carbon dioxide and hydrocarbons. Here, as the hydrocarbon refrigerant, 25 ° C., 1
A gas at atmospheric pressure is preferably used. Specifically, it is an alkane, cycloalkane, alkene or a mixture thereof having 1 to 5, preferably 1 to 4 carbon atoms. Specific examples include methane, ethylene, ethane, propylene, propane, cyclopropane, butane, isobutane, cyclobutane, methylcyclopropane, and a mixture of two or more of these. Among these, propane, butane, isobutane or a mixture thereof is preferred.

The refrigerating machine oil composition of the present invention is usually present in a refrigerating machine in the form of a refrigerating machine fluid composition mixed with the above-described refrigerant. The mixing ratio of the refrigerating machine oil and the refrigerant in the fluid composition is not particularly limited,
Refrigeration oil is preferably 1 to 5 parts per 100 parts by weight of the refrigerant.
00 parts by weight, more preferably 2 to 400 parts by weight.

The refrigerating machine oil composition of the present invention can be used as a lubricating oil for a refrigerant compressor of any refrigerating machine due to its excellent electrical properties and low hygroscopicity. Specific examples of refrigerators used include room air conditioners, package air conditioners,
Refrigerators, automotive air conditioners, dehumidifiers, freezers, freezing and refrigerated warehouses, vending machines, showcases, and cooling devices for chemical plants and the like. Further, the refrigerator oil composition of the present invention is particularly preferably used for a refrigerator having a hermetic compressor. Furthermore, the refrigerating machine oil of the present invention can be used for any type of compressor such as a reciprocating type, a rotary type, and a centrifugal type.

The structure of a refrigerating cycle in which the refrigerating machine oil composition of the present invention can be suitably used is typically as follows.
Examples include a compressor, a condenser, an expansion mechanism, an evaporator, and, if necessary, a dryer.

As the compressor, a motor consisting of a rotor and a stator in a sealed container for storing refrigerating machine oil, a rotating shaft fitted to the rotor, and connected to the motor via the rotating shaft. The high pressure refrigerant gas discharged from the compressor portion is stored in the closed container, and the high pressure refrigerant gas discharged from the compressor portion is stored in the closed container. A motor, a rotating shaft fitted to the rotor, and a compressor unit connected to the motor via the rotating shaft. The high-pressure refrigerant gas discharged from the compressor unit is sealed. Examples thereof include a low-pressure container type compressor that is directly discharged to the outside of the container.

Examples of the insulating film which is a material of the electrical insulation system of the motor section include a crystalline plastic film having a glass transition point of 50 ° C. or higher, specifically, for example, polyethylene terephthalate, polybutylene terephthalate, polyphenylene sulfide, polyether ether ketone,
Polyethylene naphthalate, polyamide imide, at least one insulating film selected from the group of polyimides, or a composite film in which a resin layer with a high glass transition temperature is coated on a film with a low glass transition temperature, deteriorates the tensile strength properties and electrical insulation properties The phenomenon hardly occurs, and it is preferably used. Further, as the magnet wire used in the motor part, enamel coating having a glass transition temperature of 120 ° C. or higher, for example, polyester, polyesterimide,
A single layer such as polyamide and polyamideimide, or a layer having an enamel coating in which a layer having a low glass transition temperature is formed as a lower layer and a layer having a higher glass transition temperature is formed as an upper layer is preferably used. Examples of the composite-coated enameled wire include a polyesterimide in a lower layer and a polyamideimide in an upper layer (AI / EI), and a polyester in a lower layer and a polyamideimide in an upper layer (AI / PE). .

[0146] The desiccant to be filled in the dryer is as follows: a pore diameter of 3.3 Å or less, a carbon dioxide gas partial pressure of 25 ° C.
Synthetic zeolites composed of silicic acid and alkali metal aluminate having a carbon dioxide absorption capacity at 50 mmHg of 1.0% or less are preferably used. Specifically, for example, trade names XH-9, XH- manufactured by Union Showa Co., Ltd.
10, XH-11 and XH-600.

[0147]

EXAMPLES Hereinafter, the content of the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

Examples 1 to 8 and Comparative Examples 1 to 7 The base oils and additives used in Examples and Comparative Examples are as follows. These were blended as shown in Tables 1 and 2, and
To 8 and Comparative Examples 1 to 7 were prepared. Tables 1 and 2 show properties (kinematic viscosities at 40 ° C. and 100 ° C., total acid value) of the obtained sample oils. [Base oil] Base oil 1 : 4-cyclohexene-1,2-dicarboxylic acid,
Esters obtained from iso-butanol and 2-ethylhexanol (ester 1: 40% by mass, ester 2: 8% by mass, ester 3: 52% by mass) In addition, cyclohexenedicarboxylic acid esters 1 to 3 in base oil 1 Is as follows.

[0149]

Embedded image

Ester 1 R ^* : iso-butyl group, R
^** : 2-ethylhexyl group ester 2 R ^* : iso-butyl group, R ^** : iso-
Butyl group ester 3 R ^* : 2-ethylhexyl group, R ^** : 2-
Ethylhexyl group. Base oil 2 : 1,2-cyclohexanedicarboxylic acid, iso
Ester obtained from butanol and 2-ethylhexanol (ester 4: 38% by mass, ester 5:12
Mass%, ester 6: 50 mass%) base oil 3 : 1,2-cyclohexanedicarboxylic acid, iso
Esters obtained from butanol and 3,5,5-trimethylhexanol (ester 5: 18% by mass, ester 7: 56% by mass, ester 8: 26% by mass) The cyclohexanedicarboxylic acid in the base oils 2 and 3 Acid esters 4 to 8 are as follows.

[0151]

Embedded image

Ester 4 R ^* : iso-butyl group, R
^** : 2-ethylhexyl group ester 5 R ^* : iso-butyl group, R ^** : iso-
Butyl group ester 6 R ^* : 2-ethylhexyl group, R ^** : 2-
Ethylhexyl group ester 7 R ^* : iso-butyl group, R ^** : 3,5
5-trimethylhexyl group Ester 8 R ^* : 3,5,5-trimethylhexyl group, R ^** : 3,5,5-trimethylhexyl group. Base oil 4 : 1,2-cyclohexanedicarboxylic acid (compound (a)), dipropylene glycol (compound (b)),
iso-butanol (compound (c-I)) and 3,5,
An ester obtained by blending 5-trimethylhexanol (compound (c-II)) in a molar ratio of 100: 15: 35: 35 and obtaining an esterification reaction.

The obtained alicyclic polycarboxylic acid ester contains the compounds represented by the above formulas (A) to (E), and the composition is as follows. In addition,
E (c-I, c-I) is a compound (E) wherein two R ² are both alkyl groups derived from the (c-I) component;
-I, c-II), one of the two R ² of the compound (E) is an alkyl group derived from the component (c-I), and the other is (c-II).
-II) an alkyl group derived from the component, E (c-I
I, c-II) is a compound (E) in which both R ² are (c
-II) an alkyl group derived from the component.

Compound (A) 12 mol% Compound (B) 7 mol% Compound (C) 21 mol% Compound (D) 2 mol% Compound (E (c-I, c-I)) 11 mol% Compound (E) (C-I, c-II)) 26 mol% Compound (E (c-II, c-II)) 21 mol%. Base oil 5 : ester of pentaerythritol and n-heptanoic acid. [Additives] Additive 1 : Triphenylphosphorothionate Additive 2 : tricresyl phosphate Additive 3 : zinc 2-diethylhexyldithiophosphate.

Next, the following tests were performed on the above sample oils. (Compatibility Test with Refrigerant) Based on JIS-K-2211 “Refrigeration oil” “Compatibility test method with refrigerant”, HFC
1 g of each sample oil is blended with 29 g of the 134a refrigerant, and whether the refrigerant and the sample oil are mutually dissolved at 0 ° C.
It was observed whether it was separated or clouded. Tables 1 and 2 show the obtained results. (Heat / Hydrolysis Stability Test) Moisture content is 500ppm
90 g of the sample oil adjusted to an autoclave is weighed into an autoclave,
After enclosing 10 g of FC134a refrigerant and a catalyst (each wire of iron, copper, and aluminum), the mixture was heated to 130 ° C., and 100 hours later, the total acid value of the sample oil was measured. Tables 1 and 2 show the obtained results.
Shown in (Lubricity test) According to ASTM D 3233, H
After a break-in operation was performed for 5 minutes under a load of 250 lb under the conditions of a flow rate of FC134a refrigerant of 10 L / h and a temperature of the sample oil of 50 ° C., the seizure load was measured. Tables 1 and 2 show the obtained results.

[0156]

[Table 1]

[0157]

[Table 2]

As is clear from the results shown in Tables 1 and 2, the sample oils of Examples 1 to 8 which are the refrigerating machine oil compositions of the present invention were obtained in Comparative Examples 1 to 4 containing no phosphorothionate compound. Compared to the sample oils of Nos. 6 and 7 and the sample oil of Comparative Example 5 which did not contain an alicyclic polycarboxylic acid ester compound as a base oil, when used with an HFC refrigerant, lubricity, heat and
All the performances of hydrolysis stability and refrigerant compatibility were excellent in a well-balanced manner.

[0159]

As described above, according to the refrigerating machine oil composition of the present invention, when used together with an HFC refrigerant and a natural refrigerant such as carbon dioxide or hydrocarbon, lubricating properties are improved.
All required performances such as heat / hydrolysis stability, refrigerant compatibility, and electrical insulation can be sufficiently satisfied in a well-balanced manner, and it is possible to achieve improvement in efficiency of the refrigeration system and maintenance of high reliability.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) C10M 129/70 C10M 129/70 137/02 137/02 137/04 137/04 137/08 137/08 137 / 10 137/10 Z // C10N 30:00 C10N 30:00 Z 30:08 30:08 40:30 40:30 (72) Inventor Katsuya Takigawa 8 Chidoricho, Naka-ku, Yokohama-shi, Kanagawa Pref. F-term in the Lubricants Department, Lubricants Department (Reference) 4H104 BB09C BB30C BB32C BB33A BB34A BH02C BH03C BH05C BH06C LA04 LA20 PA20

Claims (5)

[Claims] 1. A refrigerating machine oil composition comprising a base oil containing an alicyclic polycarboxylic acid ester compound and a phosphorothionate compound added thereto. 2. The alicyclic polycarboxylic acid ester compound comprises an alicyclic ring and the following general formula (1): —COOR (1) (wherein R represents a hydrocarbon group having 1 to 30 carbon atoms). Is a compound having at least two ester groups represented by the following formulas, and at least two of the ester groups are bonded to mutually adjacent carbon atoms on the alicyclic ring:
The refrigerating machine oil composition according to claim 1. 3. The alicyclic polycarboxylic acid ester compound has the following compounds (a) to (c): (a) having an alicyclic ring and two or more carboxyl groups;
And an alicyclic polycarboxylic acid or a derivative thereof in which at least two of the carboxyl groups are bonded to adjacent carbon atoms on the alicyclic ring, (b) a compound having two or more hydroxyl groups or a derivative thereof, and (C) The refrigerating machine oil composition according to claim 1, which is a compound obtained by using a compound having one hydroxyl group or a derivative thereof. 4. A phosphoric acid ester, an acidic phosphoric acid ester,
4. The method according to claim 1, further comprising at least one phosphorus compound selected from the group consisting of an amine salt of an acidic phosphate ester, a chlorinated phosphate ester and a phosphite ester. The refrigerator oil composition according to claim 1. 5. The refrigerator oil composition according to claim 1, further comprising an epoxy compound.