JP2017125161A - Refrigerator oil, and composition for refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigerator oil that has improved wear resistance and also has reduced frictional coefficients.SOLUTION: A refrigerator oil according to one embodiment comprises a base oil comprising an oxygen-containing organic compound, a multi-phosphoester compound, and a benzotriazole compound.SELECTED DRAWING: None

Description

  The present invention relates to a refrigerator oil and a composition for a refrigerator using the refrigerator oil.

  The refrigerator has a structure in which a mixture of refrigerant and refrigerator oil (hereinafter also referred to as “composition for refrigerator”) circulates in a closed system, and the refrigerator oil has compatibility with the refrigerant, Stability and lubrication performance are required. In order to easily satisfy these required performances, many refrigerating machine oils containing an oxygen-containing organic compound such as a vinyl ether compound as a main component are used (for example, see Patent Document 1).

On the other hand, as a refrigerant, hydrofluorocarbon (HFC) has recently been used instead of hydrochlorofluorocarbon (HCFC), which has a high environmental load. Among HFCs, saturated hydrofluorocarbons (saturated HFCs) such as R32 (difluoroethane) and R410A (mixture of difluoroethane and pentafluoroethane) are often used.
As a technology to improve the lubrication performance such as compatibility with saturated HFC refrigerants, wear resistance, and seizure resistance, a base oil composed of an oxygen-containing organic compound is added to a phosphorus atom such as tricresyl phosphate (TCP). It is known to add a phosphoric acid ester compound having one (see, for example, Patent Document 2).
It is also known that wear resistance is improved by using a phosphate ester compound having one phosphorus atom such as tricresyl phosphate (TCP) in combination with a benzotriazole-based compound in a lubricating oil composition. (See Patent Documents 3 and 4).

JP-A-6-128578 JP-A-10-130683 JP-A-8-259980 JP 7-126680 A

By the way, in recent years, demands for energy saving are increasing in various refrigerators, and it is required to improve a coefficient of performance (COP). Therefore, refrigeration oil is required to further reduce the coefficient of friction at the sliding portion of the refrigerator in order to improve COP in addition to wear resistance.
However, as shown in Patent Documents 2 to 4, even when a phosphate ester compound having one phosphorus atom, such as TCP, or a benzotriazole-based compound in addition to TCP is blended, the lubricating oil composition is In the sliding portion, it is difficult to sufficiently reduce the friction coefficient while improving the wear resistance.

  The present invention has been made in view of the above problems, and when using a refrigerating machine oil containing an oxygen-containing organic compound as a base oil, it is an object to reduce the friction coefficient while improving wear resistance. And

As a result of intensive studies, the inventors of the present invention include a base oil containing an oxygen-containing organic compound containing both a specific phosphorus compound having at least two phosphorus atoms in one molecule and a benzotriazole compound. As a result, the present inventors have found that the above problems can be solved and completed the present invention. The present invention provides the following refrigerating machine oil, a composition for a refrigerating machine, and a method for producing the refrigerating machine oil.
(1) Refrigerating machine oil containing a base oil containing an oxygen-containing organic compound, a polyphosphate ester compound, and a benzotriazole compound.
(2) A refrigerating machine composition comprising a refrigerant and the refrigerating machine oil described in (1) above.
(3) A method for producing refrigerating machine oil, wherein a refrigerating machine oil is obtained by blending at least a polyphosphate ester compound and a benzotriazole compound with a base oil containing an oxygen-containing organic compound.

  ADVANTAGE OF THE INVENTION According to this invention, the refrigerating machine oil which can reduce a friction coefficient can be provided, making a base phosphorus contain a specific phosphorus type compound and a benzotriazole type compound, making abrasion resistance favorable.

Hereinafter, the present invention will be described using embodiments.
The refrigerating machine oil according to one embodiment of the present invention includes a base oil, a polyphosphate ester compound, and a benzotriazole compound. Hereinafter, each component contained in the refrigerating machine oil will be described in detail.

[Base oil]
The base oil in this embodiment contains an oxygen-containing organic compound. Examples of oxygen-containing organic compounds include synthetic oils containing an ether group, ketone group, ester group, carbonate group, etc. in the molecule, and hetero atoms (sulfur atom, fluorine atom, chlorine atom, silicon atom, nitrogen atom) together with these groups. And synthetic oils containing atoms). More specifically, polyvinyl ethers (PVE), polyoxyalkylene glycols (PAG), poly (oxy) alkylene glycol or a copolymer of its monoether and polyvinyl ether (ECP), and polyol esters (POE) ). An oxygen-containing organic compound may be used individually by 1 type, and may use 2 or more types together.
Among these, at least one selected from polyvinyl ethers (PVE) and polyoxyalkylene glycols (PAG) is preferable, and among these, one or more selected from polyvinyl ethers (PVE) is more preferable. In addition, PVE is a polyphosphate ester compound in which R ⁹ is a group represented by the following general formula (1) and R ⁹ is represented by the general formula (2). When used for a phosphate ester compound, the friction coefficient and wear resistance are easily improved.
The oxygen-containing organic compound is a main component of the refrigerating machine oil, and the oxygen-containing organic compound is preferably contained in an amount of 70 to 99.98% by mass with respect to the total amount of the refrigerating machine oil, and 90 to 99.5% by mass. % Content is more preferable, and it is still more preferable that 93.0-99.3 mass% is contained.

Hereinafter, PVE, PAG, ECP, and POE used as the base oil will be described in more detail.
<Polyvinyl ethers (PVE)>
Polyvinyl ethers (PVE) are polymers having a structural unit derived from vinyl ether, and specifically include polyvinyl compounds having a structural unit represented by the following general formula (A-1).

R ^1a , R ^2a and R ^3a in the general formula (A-1) each independently represent a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, and they may be the same or different from each other. Specific examples of the hydrocarbon group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, various pentyl groups, and various hexyl groups. Groups, various heptyl groups, various octyl groups and other alkyl groups; cyclopentyl groups, cyclohexyl groups, various methylcyclohexyl groups, various ethylcyclohexyl groups, various dimethylcyclohexyl groups and other cycloalkyl groups; phenyl groups, various methylphenyl groups, various ethyl groups An aryl group such as a phenyl group and various dimethylphenyl groups; and an arylalkyl group such as a benzyl group, various phenylethyl groups, and various methylbenzyl groups are exemplified, and an alkyl group is preferable.
R ^1a , R ^2a and R ^3a are more preferably a hydrogen atom or an alkyl group having 3 or less carbon atoms, more preferably a hydrogen atom. In addition, r in general formula (A-1) shows the number of repetitions, The average value is a number of the range of 0-10, However, 0 is preferable.

R ^4a represents a divalent hydrocarbon group having 2 to 10 carbon atoms. Specific examples of the divalent hydrocarbon group having 2 to 10 carbon atoms include an ethylene group, a phenylethylene group, 1, 2-propylene group, 2-phenyl-1,2-propylene group, 1,3-propylene group, various butylene groups, various pentylene groups, various hexylene groups, various heptylene groups, various octylene groups, various nonylene groups, various decylene groups A divalent aliphatic hydrocarbon group such as cyclohexane, methylcyclohexane, ethylcyclohexane, dimethylcyclohexane, propylcyclohexane, and other alicyclic hydrocarbon groups having two bonding sites; various phenylene groups; Divalent aromatic carbonization such as various methylphenylene groups, various ethylphenylene groups, various dimethylphenylene groups, various naphthylenes, etc. A hydrogen group; an alkyl aromatic hydrocarbon group having a monovalent bonding site on each of the alkyl group and the aromatic part of an alkyl aromatic hydrocarbon such as toluene or ethylbenzene; an alkyl of a polyalkyl aromatic hydrocarbon such as xylene or diethylbenzene Examples include alkyl aromatic hydrocarbon groups having a bonding site in the base portion. Among these, an aliphatic hydrocarbon group having 2 to 4 carbon atoms is more preferable. The plurality of R ^4a O may be the same or different.

Further, R ^5a in formula (A-1) represents a hydrocarbon group having 1 to 10 carbon atoms, and specifically, this hydrocarbon group is a methyl group, an ethyl group, an n-propyl group, an isopropyl group. Alkyl groups such as n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, various pentyl groups, various hexyl groups, various heptyl groups, various octyl groups, various nonyl groups and various decyl groups; cyclopentyl group, Cyclohexyl groups, various methyl cyclohexyl groups, various ethyl cyclohexyl groups, various propyl cyclohexyl groups, various dimethyl cyclohexyl groups and other cycloalkyl groups; phenyl groups, various methyl phenyl groups, various ethyl phenyl groups, various dimethyl phenyl groups, various propyl phenyl groups , Various trimethylphenyl groups, various butylphenyl groups, various naphths An aryl group such as a til group; an arylalkyl group such as a benzyl group, various phenylethyl groups, various methylbenzyl groups, various phenylpropyl groups, and various phenylbutyl groups; Among these, a C1-C8 hydrocarbon group is preferable and a C1-C6 alkyl group is more preferable. The alkyl group may be linear, branched or cyclic.

Among the polyvinyl compounds having the structural unit represented by the general formula (A-1), R ^1a , R ^2a and R ^3a are all hydrogen atoms, r is 0, and R ^5a is an ethyl group. A polymer or copolymer containing 50 to 100 mol% of the structural unit and 0 to 50 mol% of a structural unit in which R ^5a is an alkyl group having 3 or 4 carbon atoms is preferable. The proportion of the structural unit in which R ^5a is an ethyl group is 70 to 100 mol%, and the proportion of the structural unit in which R ^5a is an alkyl group having 3 or 4 carbon atoms is preferably 0 to 30 mol%. Preferably, the former is 80 to 95% and the latter is 5 to 20 mol%.
As the alkyl group having 3 or 4 carbon atoms of R ^5a , n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, and tert-butyl group can be used. Is preferred.

  The polyvinyl ether-based compound has a structural unit represented by the general formula (A-1), and the number of repetitions may be appropriately selected according to the desired kinematic viscosity. Moreover, the said polyvinyl ether type compound can be manufactured by superposition | polymerization of a corresponding vinyl ether type monomer. The vinyl ether monomers that can be used here are those represented by the following general formula (A-2).

(In the formula, R ^1a , R ^2a , R ^3a , R ^4a and R ^5a and r are the same as described above.)

  Examples of the vinyl ether monomer include various monomers corresponding to the polyvinyl ether compound, such as vinyl methyl ether, vinyl ethyl ether, vinyl n-propyl ether, vinyl isopropyl ether, vinyl n-butyl ether, vinyl. -Isobutyl ether, vinyl-sec-butyl ether, vinyl-tert-butyl ether, vinyl-n-pentyl ether, vinyl-n-hexyl ether, vinyl-2-methoxyethyl ether, vinyl-2-ethoxyethyl ether, vinyl-2- Methoxy-1-methyl ethyl ether, vinyl-2-methoxy-propyl ether, vinyl-3,6-dioxaheptyl ether, vinyl-3,6,9-trioxadecyl ether, vinyl-1,4-dimethyl-3 6-dioxaheptyl ether, vinyl-1,4,7-trimethyl-3,6,9-trioxadecyl ether, vinyl-2,6-dioxa-4-heptyl ether, vinyl-2,6,9-trioxa -4-decyl ether, 1-methoxypropene, 1-ethoxypropene, 1-n-propoxypropene, 1-isopropoxypropene, 1-n-butoxypropene, 1-isobutoxypropene, 1-sec-butoxypropene, 1 -Tert-butoxypropene, 2-methoxypropene, 2-ethoxypropene, 2-n-propoxypropene, 2-isopropoxypropene, 2-n-butoxypropene, 2-isobutoxypropene, 2-sec-butoxypropene, 2 -Tert-butoxypropene, 1-methoxy-1-butene, 1-ethoxy -1-butene, 1-n-propoxy-1-butene, 1-isopropoxy-1-butene, 1-n-butoxy-1-butene, 1-isobutoxy-1-butene, 1-sec-butoxy-1- Butene, 1-tert-butoxy-1-butene, 2-methoxy-1-butene, 2-ethoxy-1-butene, 2-n-propoxy-1-butene, 2-isopropoxy-1-butene, 2-n -Butoxy-1-butene, 2-isobutoxy-1-butene, 2-sec-butoxy-1-butene, 2-tert-butoxy-1-butene, 2-methoxy-2-butene, 2-ethoxy-2-butene 2-n-propoxy-2-butene, 2-isopropoxy-2-butene, 2-n-butoxy-2-butene, 2-isobutoxy-2-butene, 2-sec-butoxy-2-butene, 2 -Tert-butoxy-2-butene and the like. These vinyl ether monomers can be produced by known methods.

A monovalent group derived from a saturated hydrocarbon, ether, alcohol, ketone, amide, nitrile or the like may be introduced into the terminal portion of the polymer represented by the general formula (A-1) by a known method. Good.
Especially, as a polyvinyl ether type compound, what has the terminal structure of following (1)-(4) is suitable.
(1) One terminal is represented by the following general formula (A-1-i), and the other terminal is represented by the following general formula (A-1-ii)

(Wherein R ^6a , R ^7a and R ^8a each independently represent a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, and they may be the same as or different from each other. R ^9a represents carbon A divalent hydrocarbon group having 2 to 10 carbon atoms, R ^10a is a hydrocarbon group having 1 to 10 carbon atoms, r1 represents a number having an average value of 0 to 10, and when there are a plurality of R ^9a O, a plurality of R ^9a O may be the same or different.)

(Wherein R ^11a , R ^12a and R ^13a each independently represent a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, which may be the same or different from each other, and R ^14a represents carbon A divalent hydrocarbon group having 2 to 10 carbon atoms, R ^15a represents a hydrocarbon group having 1 to 10 carbon atoms, r2 represents a number having an average value of 0 to 10, and when there are a plurality of R ^14a O, a plurality of R ^14a O may be the same or different.)

(2) One end of which is represented by the general formula (A-1-i) and the other end is represented by the general formula (A-1-iii)

(Wherein R ^16a , R ^17a and R ^18a each independently represent a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, and they may be the same as or different from each other. R ^19a and R ^21a each independently represents a divalent hydrocarbon group having 2 to 10 carbon atoms, which may be the same or different from each other, and R ^20a and R ^22a are each independently a carbon atom having 1 to 10 carbon atoms. Represents a hydrogen group, which may be the same or different from each other; r3 and r4 each represent an average value of 0 to 10; they may be the same or different from each other; Further to the plurality of ^{R 19a} O if there are multiple ^{R 19a} O may be the same or different and also the plurality of ^{R 21a} O if there are multiple ^{R 21a} O be the same Even if different Good.)

(3) One end of which is represented by the above general formula (A-1-i) and the remaining end has an olefinically unsaturated bond (4) One end of which is represented by the above general formula (A-1 -i) and the other terminal is represented by the general formula (A-1-iv)

(Wherein R ^23a , R ^24a and R ^25a each represent a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, and they may be the same or different from each other.)

The polyvinyl ether-based mixture may be a mixture of two or more selected from those having the terminal structures (1) to (4). Preferred examples of such a mixture include a mixture of the above (1) and (4), and a mixture of (2) and (3).
It is preferable to select a polymerization degree, a terminal structure, etc. so that a polyvinyl ether type compound may become the viscosity range of the preferable base oil mentioned later. Moreover, a polyvinyl ether type compound may be used individually by 1 type, and may be used in combination of 2 or more type.

Among the polyvinyl compounds having the structural unit represented by the general formula (A-1), in particular, one terminal is represented by the general formula (A-1-i) and the remaining terminal is represented by the general formula (A). What is represented by A-1-ii) is preferable.
Among these, in formula (A-1-i) and formula (A-1-ii), R ^6a , R ^7a , R ^8a , R ^11a , R ^12a and R ^13a are hydrogen atoms, and any of r1 and r2 Is more preferably 0, and R ^10a and R ^15a are more preferably alkyl groups having 1 to 4 carbon atoms.

<Polyoxyalkylene glycols (PAG)>
As polyoxyalkylene glycol (PAG), the compound represented by the following general formula (B-1) is mentioned. In addition, when PAG is contained in base oil, the PAG may be used alone or in combination of two or more.
R ^1b -[(OR ^2b ) _m -OR ^3b ] _n (B-1)
(In the formula, R ^1b is a hydrogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, an acyl group having 2 to 10 carbon atoms, a hydrocarbon group having 1 to 10 carbon atoms having 2 to 6 bonding parts, or An oxygen-containing hydrocarbon group having 1 to 10 carbon atoms, R ^2b is an alkylene group having 2 to 4 carbon atoms, R ^3b is a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, an acyl group having 2 to 10 carbon atoms, or carbon (The oxygen-containing hydrocarbon group of formula 1 to 10, n is an integer of 1 to 6, and m is a number with an average value of m × n of 6 to 80.)

In the general formula (B-1), the monovalent hydrocarbon group having 1 to 10 carbon atoms in each of R ^1b and R ^3b may be linear, branched, or cyclic. The hydrocarbon group is preferably an alkyl group, and specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, various butyl groups, various pentyl groups, various hexyl groups, various heptyl groups, various octyl groups, Various nonyl groups, various decyl groups, cyclopentyl groups, cyclohexyl groups and the like can be mentioned. The monovalent hydrocarbon group has good compatibility with the refrigerant when the number of carbon atoms is 10 or less. From such a viewpoint, the carbon number of the monovalent hydrocarbon group is more preferably 1 to 4.
Moreover, the hydrocarbon group part which the C2-C10 acyl group in each of R ^{< 1b>} and R ^<3b > has may be any of linear, branched or cyclic. The hydrocarbon group portion of the acyl group is preferably an alkyl group, and specific examples thereof include those having 1 to 9 carbon atoms among the alkyl groups that can be selected as the aforementioned R ^1b and R ^3b . When the carbon number of the acyl group is 10 or less, compatibility with the refrigerant is improved. A preferable acyl group has 2 to 4 carbon atoms.
When R ^1b and R ^3b are both hydrocarbon groups or acyl groups, R ^1b and R ^3b may be the same or different from each other.

Further, when n is 2 or more, a plurality of R ^{3b in} one molecule may be the same or different.
When R ^1b is a hydrocarbon group having 1 to 10 carbon atoms having 2 to 6 bonding sites, the hydrocarbon group may be chain-like or cyclic. The hydrocarbon group having two bonding sites is preferably an aliphatic hydrocarbon group, for example, ethylene group, propylene group, butylene group, pentylene group, hexylene group, heptylene group, octylene group, nonylene group, decylene group, cyclopentylene group. Examples thereof include a len group and a cyclohexylene group. Examples of other hydrocarbon groups include residues obtained by removing hydroxyl groups from bisphenols such as biphenol, bisphenol F, and bisphenol A. Further, the hydrocarbon group having 3 to 6 binding sites is preferably an aliphatic hydrocarbon group, for example, trimethylolpropane, glycerin, pentaerythritol, sorbitol, 1,2,3-trihydroxycyclohexane, 1,3,3. Examples thereof include a residue obtained by removing a hydroxyl group from a polyhydric alcohol such as 5-trihydroxycyclohexane.
The compatibility with a refrigerant | coolant becomes favorable because carbon number of this aliphatic hydrocarbon group shall be 10 or less. The preferred carbon number of the aliphatic hydrocarbon group is 2-6.

Furthermore, as the oxygen-containing hydrocarbon group having 1 to 10 carbon atoms in each of R ^1b and R ^3b , a chain aliphatic group having an ether bond, a cyclic aliphatic group (for example, a tetrahydrofurfuryl group), and the like Can be mentioned.
At least one of R ^1b and R ^3b is preferably an alkyl group, particularly an alkyl group having 1 to 4 carbon atoms.

R ^2b in the general formula (B-1) is an alkylene group having 2 to 4 carbon atoms, and examples of the oxyalkylene group of the repeating unit include an oxyethylene group, an oxypropylene group, and an oxybutylene group. The oxyalkylene groups in one molecule may be the same, or two or more oxyalkylene groups may be contained, but those containing at least an oxypropylene unit in one molecule are preferable. More preferably, it contains 50 mol% or more of oxypropylene units.
N in the general formula (B-1) is an integer of 1 to 6, and is determined according to the number of R ^1b binding sites. For example, when R ^1b is an alkyl group or an acyl group, n is 1, and when R ^1b is an aliphatic hydrocarbon group having 2, 3, 4, 5, and 6 binding sites, n is 2, 3 respectively. , 4, 5 and 6. Moreover, m is a number with an average value of m × n being 6-80. When the average value is 80 or less, the compatibility is improved. N is preferably an integer of 1 to 3, more preferably 1. However, the average value of m × n is preferably set as appropriate so as to be within a preferable viscosity range of the base oil described later.
The polyoxyalkylene glycol represented by the general formula (B-1) includes a polyoxyalkylene glycol having a hydroxyl group at the terminal, and the content of the hydroxyl group is 50 mol with respect to all terminal groups. %, It can be used preferably even if it is contained.

<Poly (oxy) alkylene glycol or a copolymer of its monoether and polyvinyl ether (ECP)>
In the refrigerating machine oil of the present embodiment, the copolymer of poly (oxy) alkylene glycol or its monoether and polyvinyl ether that can be used as a base oil is represented by the following general formula (C-1). And copolymers represented by general formula (C-2) (hereinafter referred to as polyvinyl ether copolymer I and polyvinyl ether copolymer II), respectively. Poly (oxy) alkylene glycol refers to both polyalkylene glycol and polyoxyalkylene glycol.

R ^1c , R ^2c and R ^3c in the general formula (C-1) each independently represent a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, which may be the same or different from each other, and R ^5c is A divalent hydrocarbon group having 2 to 4 carbon atoms, R ^6c is an aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, an aromatic hydrocarbon group having 1 to 20 carbon atoms, and 2 to 20 carbon atoms An acyl group or an oxygen-containing hydrocarbon group having 2 to 50 carbon atoms, R ^4c represents a hydrocarbon group having 1 to 10 carbon atoms, and when there are a plurality of R ^{1c to} R ^6c , they may be the same or different. Good.
Here, the hydrocarbon group having 1 to 8 carbon atoms of R ^{1c to} R ^3c is specifically a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec- Alkyl groups such as butyl group, tert-butyl group, various pentyl groups, various hexyl groups, various heptyl groups, various octyl groups; cyclopentyl group, cyclohexyl group, various methylcyclohexyl groups, various ethylcyclohexyl groups, various dimethylcyclohexyl groups, etc. A cycloalkyl group; an aryl group such as various dimethylphenyl groups; and an arylalkyl group such as a benzyl group, various phenylethyl groups, and various methylbenzyl groups. In addition, as each of these ^R1c , ^R2c, and ^R3c, a hydrogen atom is especially preferable.

On the other hand, specific examples of the divalent hydrocarbon group having 2 to 4 carbon atoms represented by R ^5c include divalent alkylene groups such as a methylene group, an ethylene group, various propylene groups, and various butylene groups.
Incidentally, v in the general formula ^(C-1), represents a repeating number of ^{R 5c} O, the average value thereof is 1 to 50, preferably 1 to 20, more preferably 1 to 10, particularly preferably from 1 to 5 The number of ranges. When R ^{5c O} there is a plurality, the plurality of R ^{5c O} may be the same or different. v may be the same for each structural unit, or may be different.
W is 1 to 50, preferably 1 to 10, more preferably 1 to 2, particularly preferably 1, u is 0 to 50, preferably 2 to 25, more preferably 5 to 15, When there are a plurality of w and u, each of them may be block or random.

Furthermore, R ^6c in formula (C-1) preferably represents an alkyl group having 1 to 10 carbon atoms, an acyl group having 2 to 10 carbon atoms, or an oxygen-containing hydrocarbon group having 2 to 50 carbon atoms.
Specific examples of the alkyl group having 1 to 10 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, and various pentyl groups. Group, various hexyl groups, various heptyl groups, various octyl groups, various nonyl groups, various decyl groups, cyclopentyl groups, cyclohexyl groups, various methylcyclohexyl groups, various ethylcyclohexyl groups, various propylcyclohexyl groups, various dimethylcyclohexyl groups, etc. .
Examples of the acyl group having 2 to 10 carbon atoms include acetyl group, propionyl group, butyryl group, isobutyryl group, valeryl group, isovaleryl group, piperoyl group, benzoyl group, and toluoyl group.
Further, specific examples of the oxygen-containing hydrocarbon group having 2 to 50 carbon atoms include methoxymethyl group, methoxyethyl group, methoxypropyl group, 1,1-bismethoxypropyl group, 1,2-bismethoxypropyl group, ethoxy A propyl group, a (2-methoxyethoxy) propyl group, a (1-methyl-2-methoxy) propyl group and the like can be preferably exemplified.

In the general formula (C-1), the hydrocarbon group having 1 to 10 carbon atoms represented by R ^4c specifically includes a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, Alkyl groups such as isobutyl group, various pentyl groups, various hexyl groups, various heptyl groups, various octyl groups, various nonyl groups, various decyl groups; cyclopentyl group, cyclohexyl group, various methylcyclohexyl groups, various ethylcyclohexyl groups, various propylcyclohexyl groups Groups, cycloalkyl groups such as various dimethylcyclohexyl groups; phenyl groups, various methylphenyl groups, various ethylphenyl groups, various dimethylphenyl groups, various propylphenyl groups, various trimethylphenyl groups, various butylphenyl groups, various naphthyl groups, etc. Aryl group; benzyl group, various phenylethyl groups, An arylalkyl group such as various methylbenzyl groups, various phenylpropyl groups, and various phenylbutyl groups is shown.
By making the polyvinyl ether copolymer I having the structural unit represented by the general formula (C-1) into a copolymer, lubricity, insulation, hygroscopicity and the like are improved while satisfying compatibility. be able to.

On the other hand, in the polyvinyl ether copolymer II represented by the general formula (C-2), R ^{1c to} R ^5c and v are the same as described above. R ^4c and R ^5c may be the same or different when there are a plurality of R ^4c and R ^5c . x and y each represent a number from 1 to 50, and when there are a plurality of x and y, each may be a block or random. X ^c and Y ^c each independently represent a hydrogen atom, a hydroxyl group, or a hydrocarbon group having 1 to 20 carbon atoms.
In addition, it is preferable that the repeating numbers u, w, x, and y in the general formulas (C-1) and (C-2) are appropriately selected so as to have a desired viscosity described later. Moreover, about the manufacturing method of polyvinyl ether type | system | group copolymers I and II, what is necessary is just a method by which it is obtained, and there is no restriction | limiting in particular.

One end of the vinyl ether copolymer I represented by the general formula (C-1) is represented by the following general formula (C-3) or (C-4), and the remaining ends are the following: It can be set as the polyvinyl ether type copolymer I which has a structure represented by general formula (C-5) or general formula (C-6).

(In (C-3) and (C-4) above, R ^{1c to} R ^6c and v are the same as described above.)

(In (C-5) and (C-6) above, R ^{1c to} R ^6c and v are the same as described above.)

<Polyol esters (POE)>
In the refrigerating machine oil, as a polyol ester that can be used as a base oil, an ester of a diol or a polyol having 3 to 20 hydroxyl groups and a fatty acid having 1 to 24 carbon atoms is preferably used. Here, as the diol, for example, ethylene glycol, 1,3-propanediol, propylene glycol, 1,4-butanediol, 1,2-butanediol, 2-methyl-1,3-propanediol, 1,5- Pentanediol, neopentylglycol, 1,6-hexanediol, 2-ethyl-2-methyl-1,3-propanediol, 1,7-heptanediol, 2-methyl-2-propyl-1,3-propanediol 2,2-diethyl-1,3-propanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, etc. Can be mentioned. Examples of the polyol include trimethylolethane, trimethylolpropane, trimethylolbutane, di- (trimethylolpropane), tri- (trimethylolpropane), pentaerythritol, di- (pentaerythritol), and tri- (pentaerythritol). Glycerin, polyglycerin (glycerin 2-20 mer), 1,3,5-pentanetriol, sorbitol, sorbitan, sorbitol glycerin condensate, polyvalent alcohols such as adonitol, arabitol, xylitol, mannitol, xylose, arabinose, Ribose, rhamnose, glucose, fructose, galactose, mannose, sorbose, cellobiose, maltose, isomaltose, trehalose, sucrose, raffinose, gen Anosu, saccharides such as Merenjitosu, and their partially etherified products and methyl glucosides (glycosides) and the like. Among these, as the polyol, neopentyl glycol, trimethylol ethane, trimethylol propane, trimethylol butane, di- (trimethylol propane), tri- (trimethylol propane), pentaerythritol, di- (pentaerythritol), tri Hindered alcohols such as-(pentaerythritol) are preferred.

As the fatty acid, the number of carbon atoms is not particularly limited, but those having 1 to 24 carbon atoms are usually used. Among the fatty acids having 1 to 24 carbon atoms, those having 3 or more carbon atoms are preferable, those having 4 or more carbon atoms are more preferable, and those having 5 or more carbon atoms are even more preferable from the viewpoint of lubricity. Moreover, from a compatible point with a refrigerant | coolant, a C18 or less thing is preferable, a C12 or less thing is more preferable, and a C9 or less thing is still more preferable.
Moreover, any of a linear fatty acid and a branched fatty acid may be sufficient, a linear fatty acid is preferable from the point of lubricity, and a branched fatty acid is preferable from the point of hydrolysis stability. Furthermore, either a saturated fatty acid or an unsaturated fatty acid may be used.

Examples of fatty acids include isobutyric acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid , Linear or branched ones such as nonadecanoic acid, icosanoic acid and oleic acid, or so-called neoacids in which the α carbon atom is quaternary. More specifically, isobutyric acid, valeric acid (n-pentanoic acid), caproic acid (n-hexanoic acid), enanthic acid (n-heptanoic acid), caprylic acid (n-octanoic acid), pelargonic acid (n- Nonanoic acid), capric acid (n-decanoic acid), oleic acid (cis-9-octadecenoic acid), isopentanoic acid (3-methylbutanoic acid), 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-ethylhexanoic acid 3,5,5-trimethylhexanoic acid and the like are preferable.
The polyol ester may be a partial ester remaining without all the hydroxyl groups of the polyol being esterified, or may be a complete ester in which all the hydroxyl groups are esterified, or a partial ester and a complete ester. A complete ester is preferable.

  Among these polyol esters, since they are more excellent in hydrolysis stability, neopentyl glycol, trimethylol ethane, trimethylol propane, trimethylol butane, di- (trimethylol propane), tri- (trimethylol propane), pentaerythritol. More preferred are esters of hindered alcohols such as di- (pentaerythritol), tri- (pentaerythritol), and even more preferred are esters of neopentyl glycol, trimethylol ethane, trimethylol propane, trimethylol butane and pentaerythritol, The ester of pentaerythritol is most preferred because it is particularly excellent in compatibility with the refrigerant and hydrolytic stability.

  Specific examples of preferred polyol esters include neopentyl glycol and isobutyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, oleic acid, isopentanoic acid, 2-methylhexanoic acid and 2-ethylpentane. Acid, 2-ethylhexanoic acid, 3,5,5-trimethylhexanoic acid selected from one or two or more fatty acid diesters, trimethylolethane and isobutyric acid, valeric acid, caproic acid, enanthic acid, capryl One or two selected from acids, pelargonic acid, capric acid, oleic acid, isopentanoic acid, 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-ethylhexanoic acid, 3,5,5-trimethylhexanoic acid Triesters with the above fatty acids, trimethylolpropane and isobutyric acid, valeric acid, capron , Enanthic acid, caprylic acid, pelargonic acid, capric acid, oleic acid, isopentanoic acid, 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-ethylhexanoic acid, 3,5,5-trimethylhexanoic acid Triesters with one or more fatty acids, trimethylolbutane and isobutyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, oleic acid, isopentanoic acid, 2-methylhexanoic acid, Triesters with one or more fatty acids selected from 2-ethylpentanoic acid, 2-ethylhexanoic acid, 3,5,5-trimethylhexanoic acid, pentaerythritol and isobutyric acid, valeric acid, caproic acid, Enanthic acid, caprylic acid, pelargonic acid, capric acid, oleic acid, isopentanoic acid, 2-methyl San acid, 2-ethyl pentanoic acid, 2-ethylhexanoic acid, 3,5,5 tetraester of one or two or more fatty acids selected from the trimethylhexanoic acid.

  The ester with two or more fatty acids may be a mixture of two or more of one kind of fatty acid and a polyol. Two or more kinds of mixed fatty acid and an ester of a polyol, particularly an ester of a mixed fatty acid and a polyol Excellent low temperature characteristics and compatibility with refrigerants.

The oxygen-containing organic compound contained in the refrigerating machine oil preferably has a 100 ° C. kinematic viscosity of 1 to 30 mm ² / s. When the kinematic viscosity is 1 mm ² / s or more, good lubrication performance is exhibited and the sealing performance is improved. Moreover, if it is 30 mm < ² > / s or less, it is excellent in compatibility with a refrigerant | coolant and refrigerator oil, and energy saving property becomes favorable. From the above viewpoint, the 100 ° C. kinematic viscosity of the oxygen-containing organic compound is more preferably ^{2 to 20} mm ² / s, and further preferably 3 to 15 mm ² / s.
The base oil may consist of only the oxygen-containing organic compound, but in addition to the oxygen-containing organic compound, mineral oil, synthetic oil other than the oxygen-containing organic compound, or these may be used as long as the object of the present invention is not impaired. Both of them may be contained. The base oil other than the oxygen-containing organic compound is preferably less than 10% by mass, more preferably less than 5% by mass, and more preferably less than 1% by mass with respect to the total amount of refrigerating machine oil. preferable. Like the base oil also oxygen-containing organic compound other than the oxygen-containing organic compound, 100 ° C. kinematic viscosity is preferably 1 to 30 mm ² / s, more preferably 2 to 20 mm ² / s, more preferably 3 to 15 mm ² / s.

[Polyphosphate compounds]
The polyphosphate ester compound contained in the refrigerating machine oil of this embodiment is a phosphate ester compound having at least two phosphate skeletons in one molecule. The polyphosphate ester compound is specifically a compound represented by the following general formula (1).

(However, in the formula (1), n represents an integer of 1 to ^10, R 1 to R ⁸ each independently represent a hydrogen atom or an alkyl group having a carbon number of 1 to 20, R ⁹ is 2 carbon atoms Represents a divalent hydrocarbon group of ˜20.)
The refrigerating machine oil of the present embodiment contains the above-mentioned polyphosphate ester compound and a benzotriazole compound described later, thereby reducing the coefficient of friction in the sliding portion of the refrigerator and improving the wear resistance. It becomes possible.
In addition, a polyphosphate ester type compound may be used individually by 1 type, and may use 2 or more types together.

In general formula (1), the alkyl group in R ^{1 to} R ⁸ may be linear, branched or cyclic, and is a methyl group, ethyl group, n-propyl group, isopropyl group, various butyl groups, or various pentyl groups. Group, various hexyl groups, various heptyl groups, various octyl groups, various nonyl groups, various decyl groups, various undecyl groups, various dodecyl groups, various tridecyl groups, various tetradecyl groups, various pentadecyl groups, various hexadecyl groups, various heptadecyl groups, Examples include various octadecyl groups.
R ^{1 to} R ⁸ are preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or a methyl group, and most preferably a hydrogen atom.

R ⁹ in the general formula (1) is preferably an alkylene group, an arylene group, or a hydrocarbon group composed of an arylene group and an alkylene group, and preferably includes an arylene group. Here, when R ⁹ is an alkylene group, the alkylene group is, for example, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group, a nonylene group, a decylene group, an undecylene group, A dodecylene group, a tetradecylene group, a hexadecylene group, an octadecylene group, an icosalen group, etc. are mentioned, These may be linear or various branched ones. The alkylene group may be a cyclic alkylene group such as a cyclopropylene group, a cyclobutylene group, a cyclopentylene group, a cyclohexylene group, a cycloheptylene group, a cyclooctylene group, a dicyclopentylene group, or a tricyclopentylene group. Good.

The arylene group may be either substituted or unsubstituted, and specific examples include a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted biphenyl group, The arylene group is preferably unsubstituted. Of these, a phenylene group is preferred.
Further, when R ⁹ is composed of an arylene group and an alkylene group, the arylene group is the same as described above, and examples of the alkylene group include linear, branched, or cyclic alkylene groups having 1 to 14 carbon atoms. For example, a methylene group or the same as described above can be used. Further, it is preferably a linear or branched alkylene group having 1 to 5 carbon atoms, specifically, various ethylene groups such as methylene group, 1,1-ethylene, 1,2-ethylene, Examples include various propylene groups such as 3-propylene, 1,2-propylene, and 2,2-propylene, various butylene groups, and various pentylene groups. Among these, 2,2-propylene group (—C (CH ₃ ) ₂ -) Is more preferable.
Moreover, in General formula (1), 1-8 are preferable and n may be a single-piece | unit which consists of specific 1 type, and n may be a mixture which consists of 2 or more types. n is more preferably 1 to 3, and n is particularly preferably 1 among them. By reducing n, the molecular weight is reduced, so that the solubility in the base oil can be easily increased, and the friction coefficient can be easily reduced.

Further, suitable specific examples of R ⁹ is preferably a group represented by the following general formula (2) to (4), the general formula (2) or more preferably a group represented by (3), The group represented by the general formula (2) is more preferable. In addition, although general formula (2) may be any of ortho form, meta form and para form, meta form is preferred.

Specific examples of preferable polyphosphate ester compounds include compounds represented by the following general formulas (5) and (6). In these, the compound shown by the following general formula (5) is more preferable.

In Formula (5), n represents an integer of 1 to 10, preferably 1 to 8, and more preferably 1 to 5. In addition, the polyphosphate ester compound represented by the general formula (5) exhibits the effect of improving the wear resistance and reducing the friction coefficient when the base oil contains PVE as the oxygen-containing organic compound. When n is 1 to 3, particularly when n is 1, the effect is easily exhibited.

The content of the polyphosphate ester compound is preferably 0.01 to 5.0 mass% with respect to the total amount of the refrigerating machine oil. In this embodiment, by containing 0.01 mass% or more of the polyphosphate ester compound, the friction coefficient in the sliding portion is effectively reduced while maintaining the stability and wear resistance of the refrigeration oil well. It is possible to make it. Moreover, by setting it as 5.0 mass% or less, it becomes easy to dissolve a polyphosphate ester-type compound in base oil, and it becomes easy to exhibit the effect according to content.
In order to effectively reduce the coefficient of friction in the sliding portion while taking into account the stability and wear resistance of the refrigerating machine oil, the content of the polyphosphate ester compound is 0.5 to 5. 0 mass% is more preferable, 1.0-5.0 mass% is further more preferable, and 1.0-3.0 mass% is especially preferable.

[Benzotriazole compounds]
Examples of the benzotriazole compounds contained in the refrigerating machine oil include benzotriazole and benzotriazole derivatives.
The benzotriazole is specifically 1,2,3-benzotriazole represented by the general formula (7). Moreover, as a derivative | guide_body of benzotriazole, the alkyl benzotriazole represented by the following general formula (8), the aminoalkyl benzotriazole represented by General formula (9), etc. are mentioned.

In formula (8), R ¹¹ is a linear or branched alkyl group having 1 to 4 carbon atoms, and a is an integer of 1 to 3. When there are a plurality of R ^{11 s} , they may be the same or different. Specific examples of R ¹¹ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group.
R ¹¹ preferably represents a methyl group or an ethyl group, and a is preferably 1 or 2, and more preferably 1.

In the general formula (9), R ¹² is a linear or branched alkyl group having 1 to 4 carbon atoms, b is an integer of 0 to 3, R ¹³ is a methylene group or ethylene group, R ¹⁴ and R ¹⁵ each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 18 carbon atoms. When there are a plurality of R ^{12 s} , they may be the same or different. R ¹⁴ and R ¹⁵ may be the same as or different from each other.
Examples of the alkyl group for R ¹² include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. Examples of the alkyl group for R ¹⁴ and R ¹⁵ include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, various pentyl groups, and various types. Hexyl group, various heptyl groups, various octyl groups, various nonyl groups, various decyl groups, various undecyl groups, various dodecyl groups, various tridecyl groups, various tetradecyl groups, various pentadecyl groups, various hexadecyl groups, various heptadecyl groups, various octadecyl groups And the like.
R ¹² is preferably a methyl group or an ethyl group, R ¹⁴ and R ¹⁵ are preferably linear or branched alkyl groups having 1 to 12 carbon atoms, and b is preferably a number of 0 or 1.

As a compound represented by the formula (9), R ¹² is a methyl group, b is 0 or 1, R ¹³ is a methylene group or an ethylene group, and R ¹⁴ and R ¹⁵ are linear or branched. A branched alkyl group having 1 to 12 carbon atoms such as dialkylaminoalkylbenzotriazole, dialkylaminoalkyltolyltriazole, or a mixture thereof is preferable, and among them, those having 4 to 12 carbon atoms in R ¹⁴ and R ¹⁵ are more preferable. preferable.
In addition, a benzotriazole type compound may be used individually by 1 type, and may use 2 or more types together.
Specific examples of preferred benzotriazole compounds include 1,2,3-benzotriazole, methylbenzotriazole, 1- [N, N-bis (2-ethylhexyl) aminomethyl] methylbenzotriazole, and the like.

  The content of the benzotriazole-based compound is preferably 0.01% by mass or more based on the total amount of refrigerating machine oil. In the present embodiment, the friction coefficient can be reduced while improving the wear resistance by using the polyphosphate ester compound in combination with the content of 0.01% by mass or more. In order to appropriately obtain these effects, the content of the benzotriazole-based compound is more preferably 0.01 to 1.00% by mass, and further preferably 0.02 to 1.00% by mass. .

[Other additives]
The refrigerating machine oil according to the present embodiment includes, in addition to the polyphosphate ester compound and the benzotriazole compound, an antioxidant, an acid scavenger, an antifoaming agent, an extreme pressure agent, an oil agent, an oxygen scavenger, Any one or more of various additives such as metal deactivators and rust inhibitors may be contained, and among these, any of antioxidants, acid scavengers, and antifoaming agents It is preferable to contain 1 type (s) or 2 or more types. The additives other than the polyphosphate ester compound and the benzotriazole compound are preferably contained in an amount of 15% by mass or less, more preferably 0 to 5% by mass with respect to the total amount of the refrigerating machine oil.
Antioxidants include 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,2′-methylenebis (4-methyl-6-tert). -Butylphenol) and other amine-based antioxidants such as phenyl-α-naphthylamine and N, N′-di-phenyl-p-phenylenediamine are preferred, and phenolic antioxidants are preferred. Content of antioxidant is 0.01-5 mass% normally with respect to refrigeration oil whole quantity from points, such as an effect and economical efficiency, Preferably it is 0.05-3 mass%.

Examples of the acid scavenger include epoxy compounds such as phenyl glycidyl ether, alkyl glycidyl ether, alkylene glycol glycidyl ether, cyclohexene oxide, α-olefin oxide, and epoxidized soybean oil. Of these, phenyl glycidyl ether, alkyl glycidyl ether, alkylene glycol glycidyl ether, cyclohexene oxide, and α-olefin oxide are preferable in terms of compatibility.
The alkyl group of the alkyl glycidyl ether and the alkylene group of the alkylene glycol glycidyl ether may have a branch, and the number of carbon atoms is usually from 3 to 30, preferably from 4 to 24, particularly preferably from 6 to 16. is there. The α-olefin oxide generally has a total carbon number of 4 to 50, preferably 4 to 24, particularly 6 to 16. In the present embodiment, one type of acid scavenger may be used, or two or more types may be used in combination. Moreover, the content is 0.005-5 mass% normally with respect to refrigerating machine oil whole quantity from the point of the effect and suppression of sludge generation | occurrence | production, Preferably it is 0.05-3 mass%.
In this embodiment, the stability of refrigerating machine oil can be improved by containing an acid scavenger.
Moreover, as an antifoamer, a silicone type antifoamer, a fluorinated silicone type antifoamer, etc. can be mentioned, for example. The content of the antifoaming agent is usually 0.005 to 2% by mass, preferably 0.01 to 1% by mass with respect to the total amount of the refrigerating machine oil.

Examples of extreme pressure agents include phosphorous extreme pressure agents such as phosphate esters, acid phosphate esters, phosphite esters, acid phosphite esters, and amine salts thereof.
These phosphorus-based extreme pressure agents have one phosphorus atom in the molecule, and include tricresyl phosphate, trithiophenyl phosphate, tri (nonylphenyl) phosphite, dioleyl hydrogen phosphite, 2-ethylhexyl. Examples thereof include diphenyl phosphite.

Moreover, as an extreme pressure agent, the metal salt of carboxylic acid is mentioned. The metal salt of a carboxylic acid here is preferably a carboxylic acid having 3 to 60 carbon atoms, more preferably a metal salt of a fatty acid having 3 to 30 carbon atoms, particularly 12 to 30 carbon atoms. Moreover, the metal salt of the dimer acid and trimer acid of the said fatty acid, and C3-C30 dicarboxylic acid can be mentioned. Among these, a metal salt of a fatty acid having 12 to 30 carbon atoms and a dicarboxylic acid having 3 to 30 carbon atoms is particularly preferable.
On the other hand, as the metal constituting the metal salt, an alkali metal or an alkaline earth metal is preferable, and an alkali metal is particularly optimal.
Furthermore, examples of extreme pressure agents other than the above include sulfur-based extreme pressure agents such as sulfurized fats and oils, sulfurized fatty acids, sulfurized esters, sulfurized olefins, dihydrocarbyl polysulfides, thiocarbamates, thioterpenes, and dialkylthiodipropionates. be able to.
The content of the extreme pressure agent is usually 0.001 to 5% by mass, particularly preferably 0.005 to 3% by mass, based on the total amount of refrigerating machine oil, from the viewpoint of lubricity and stability.
One of these extreme pressure agents may be used alone, or two or more thereof may be used in combination.

Examples of oil-based agents include aliphatic saturated and unsaturated monocarboxylic acids such as stearic acid and oleic acid, polymerized fatty acids such as dimer acid and hydrogenated dimer acid, hydroxy fatty acids such as ricinoleic acid and 12-hydroxystearic acid, lauryl Aliphatic saturated and unsaturated monoalcohols such as alcohol, oleyl alcohol, aliphatic saturated and unsaturated monoamines such as stearylamine and oleylamine, aliphatic saturated and unsaturated monocarboxylic amides such as lauric acid amide and oleic acid amide, glycerin And partial esters of polyhydric alcohols such as sorbitol and aliphatic saturated or unsaturated monocarboxylic acids.
These may be used individually by 1 type and may be used in combination of 2 or more type. Moreover, the content is 0.01-10 mass% normally with respect to refrigerating machine oil whole quantity, Preferably it selects in the range of 0.1-5 mass%.

Examples of the oxygen scavenger include 4,4′-thiobis (3-methyl-6-tert-butylphenol), diphenyl sulfide, dioctyl diphenyl sulfide, dialkyl diphenylene sulfide, benzothiophene, dibenzothiophene, phenothiazine, benzothiapyran, thiapyran, thianthrene, Examples thereof include sulfur-containing aromatic compounds such as dibenzothiapyran and diphenylene disulfide, aliphatic unsaturated compounds such as various olefins, dienes and trienes, and terpenes having a double bond.
Examples of the metal deactivator include N- [N, N′-dialkyl (C3-C12 alkyl group) aminomethyl] triazole.
Examples of the rust preventive include metal sulfonates, aliphatic amines, organic phosphites, organic phosphates, organic sulfonates, organic phosphates, alkenyl succinates, polyhydric alcohol esters, and the like. be able to.
The refrigerating machine oil according to the present embodiment can further contain other known various additives as long as the object of the present invention is not impaired.

[Refrigerant]
The refrigerating machine oil according to the present embodiment is used in a refrigerant environment, and specifically is used in a refrigerating machine after being mixed with a refrigerant. That is, in this embodiment, it uses for a refrigerator with the form of the composition for refrigerators containing refrigerator oil and a refrigerant | coolant. In the composition for a refrigerator, the amount of refrigerant and refrigerator oil used is preferably in the range of 99/1 to 10/90, more preferably 95/5 to 30/70, in terms of mass ratio of refrigerant / refrigerant oil. When this mass ratio is within the above range, the refrigerating capacity and lubricity in the refrigerator can be made appropriate.
Examples of the refrigerant to be used include one or two or more kinds selected from fluorinated hydrocarbons, natural refrigerants such as carbon dioxide, hydrocarbons, and ammonia.

<Fluorohydrocarbon>
Examples of the fluorinated hydrocarbon include a saturated fluorinated hydrocarbon compound (saturated HFC) and an unsaturated fluorinated hydrocarbon compound (HFO).
The saturated fluorinated hydrocarbon compound is usually a fluoride of an alkane having 1 to 4 carbon atoms, preferably a fluoride of an alkane having 1 to 3 carbon atoms, and an alkane having 1 to 2 carbon atoms (methane or ethane). Fluoride is more preferred. Specific methane or ethane fluorides include trifluoromethane (R23), difluoromethane (R32), 1,1-difluoroethane (R152a), 1,1,1-trifluoroethane (R143a), 1,1, 2-trifluoroethane (R143), 1,1,1,2-tetrafluoroethane (R134a), 1,1,2,2-tetrafluoroethane (R134), 1,1,1,2,2-penta Fluoroethane (R125) can be mentioned, among which difluoromethane and 1,1,1,2,2-pentafluoroethane are preferable.
These saturated fluorinated hydrocarbon compounds may be used alone or in combination of two or more. Here, as an example in the case of using 2 or more types in combination, 2 mixed refrigerants in which 2 or more types of saturated fluorinated hydrocarbon compounds having 1 to 3 carbon atoms are mixed and 2 or 2 saturated fluorinated hydrocarbon compounds having 1 to 2 carbon atoms are used. The mixed refrigerant which mixed the seed | species or more is mentioned.
Specific examples of the mixed refrigerant include a mixture of R32 and R125 (R410A), a mixture of R125, R143a and R134a (R404A), a mixture of R32, R125 and R134a (R407A, R407C, R407E, etc.), and a mixture of R125 and R143a ( R507A) and the like.

The unsaturated fluorinated hydrocarbon compound has a carbon-carbon double bond, such as a linear or branched chain olefin having 2 to 6 carbon atoms or a fluorinated product of a cyclic olefin having 4 to 6 carbon atoms. Can be mentioned.
More specifically, ethylene introduced with 1 to 3 fluorine atoms, propene introduced with 1 to 5 fluorine atoms, butene introduced with 1 to 7 fluorine atoms, 1 to 9 Pentene introduced with fluorine atoms, hexene introduced with 1 to 11 fluorine atoms, cyclobutene introduced with 1 to 5 fluorine atoms, cyclopentene introduced with 1 to 7 fluorine atoms, 1 to 9 And cyclohexene introduced with one fluorine atom.
Among these unsaturated fluorinated hydrocarbon compounds, propene fluoride is preferable, propene having 3 to 5 fluorine atoms introduced is more preferable, and propene having 4 fluorine atoms introduced is most preferable. Specifically, 1,3,3,3-tetrafluoropropene (HFO1234ze) and 2,3,3,3-tetrafluoropropene (HFO1234yf) are preferable compounds.
These unsaturated fluorinated hydrocarbon compounds may be used alone or in combination of two or more, or may be used in combination with a refrigerant other than the unsaturated fluorinated hydrocarbon compound. . Here, a mixed refrigerant of a saturated fluorinated hydrocarbon compound and an unsaturated fluorinated hydrocarbon compound can be given as an example of a case where the refrigerant is used in combination with a refrigerant other than the unsaturated fluorinated hydrocarbon compound. Specific examples of the mixed refrigerant include a mixed refrigerant of R-32, HFO1234ze, and R152a (AC5, the mixing ratio is 13.23: 76.20: 9.96).

<Natural refrigerant>
Examples of natural refrigerants include carbon dioxide (carbon dioxide), hydrocarbons such as propane, n-butane, isobutane, 2-methylbutane, n-pentane, cyclopentane, isobutane, and normal butane, and ammonia. 1 type may be used independently, 2 or more types may be used in combination, and it may combine with refrigerants other than a natural system refrigerant. Here, as an example in the case of using it in combination with refrigerants other than natural refrigerants, a mixed refrigerant with a saturated fluorinated hydrocarbon compound, an unsaturated fluorinated hydrocarbon compound, or both of these can be mentioned. Specific examples of the mixed refrigerant include a mixed refrigerant of carbon dioxide, HFO1234ze, and R134a (AC6, blending ratio is 5.15: 79.02: 15.41).
In the present embodiment, among these refrigerants, fluorinated hydrocarbons are preferable, and saturated fluorinated hydrocarbon compounds are more preferable. The refrigerant may be a mixture of a saturated fluorinated hydrocarbon compound and another refrigerant, but is preferably composed of only a saturated fluorinated hydrocarbon compound. Among them, R32, R125, and a mixture of these, R410A is more preferable, and it is particularly preferable that the refrigerant includes R32. In this case, the ratio of R32 in the total refrigerant is preferably 50% by mass or more based on the total amount of the refrigerant, 70 mass% or more is more preferable, and a refrigerant of R32 alone is most preferable.

[refrigerator]
The refrigerating machine oil or the refrigerating machine composition according to the present embodiment is used by filling the inside of the refrigerating machine. Here, the refrigerator is a compressor, a condenser, an expansion mechanism (such as an expansion valve) and an evaporator, or a refrigeration cycle having a configuration in which a compressor, a condenser, an expansion mechanism, a dryer and an evaporator are essential. Have. The refrigerating machine oil is used for lubricating a sliding portion provided in, for example, a compressor.
The sliding part of the refrigerator is preferably between metal and metal, and examples of the metal of the sliding part include iron and steel materials. The refrigerating machine oil of the present embodiment can reduce the friction coefficient while improving the wear resistance between iron and steel materials.
The refrigerating machine oil and the refrigerating machine composition more specifically include various refrigerators such as a car air conditioner, a gas heat pump (GHP), an air conditioner, a refrigerator, a vending machine, a showcase, a water heater, and a floor heater. It can be used in systems, hot water supply systems, and heating systems.

[Method for producing refrigerating machine oil]
The manufacturing method of the refrigerating machine oil which concerns on one Embodiment of this invention mix | blends at least the said polyphosphate ester type compound and a benzotriazole type compound with the base oil containing the above-mentioned oxygen-containing organic compound, and manufactures refrigerating machine oil. It is. Moreover, in this method, you may mix | blend any 1 type (s) or 2 or more types of the above-mentioned various additives other than a polyphosphate ester type compound and a benzotriazole type compound. Since the detailed description of the base oil, the polyphosphate ester compound, the benzotriazole compound, and various additives is the same as described above, the description thereof is omitted.

  EXAMPLES The present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. The properties of the base oil, the characteristics of the refrigerator oil and the composition for the refrigerator were determined according to the following procedure.

(1) Kinematic viscosity Measured using a glass capillary viscometer according to JIS K2283: 2000.
(2) Lubricity test Using a hermetically sealed block-on-ring friction tester (LFW-1), in the R32 (difluoromethane) refrigerant environment, the friction coefficient of the sliding part of each refrigerator composition, and The ring wear amount was measured under the following conditions.
Ring: FC250 Block: SKH51 Rotation speed: 1000rpm
Familiarization: Load 300N x 1min Load: 500N Time: 30min Oil temperature: 80 ° C
Refrigerant pressure: 0.4 MPa

Examples 1-16, Comparative Examples 1-16
Each example shown in Table 1 and the refrigerating machine oil of the comparative example and the composition for a refrigerating machine using the refrigerating machine oil were prepared, and a lubricity test was performed. The results are shown in Table 1.

* In each of the examples and comparative examples, the base oil and additives are as follows.
[Base oil]
PVE: copolymer of ethyl vinyl ether and isobutyl vinyl ether (molar ratio 9: 1, 100 ° C. kinematic viscosity 7.8 mm ² / s), both ends are represented by general formula (A-1-i) and general formula (A- 1-ii), R ^{6a to} R ^8a , R ^{11a to} R ^13a are hydrogen atoms, r1 and r2 are both 0, and R ^10a and R ^15a are an ethyl group or an isobutyl group. It is.
PAG: Polyoxypropylene glycol (100 ° C. kinematic viscosity 9.8 mm ² / s)
ECP: Polypropylene glycol (PPG) / polyethyl vinyl ether (PEV) copolymer (PPG / PEV molar ratio 5/5, 100 ° C. kinematic viscosity 11.2 mm ² / s)
POE: pentaerythritol octanoic acid (C8 acid) nonanoic acid (C9 acid) ester (C8 acid / C9 acid molar ratio 1 / 1.1, 100 ° C. kinematic viscosity 8.6 mm ² / s)
[Additive]
Polyphosphate ester compound 1: Compound in which n is a mixture of 1 to 3 in the above general formula (5) Polyphosphate ester compound 2: Compound in which n is a mixture of 1 to 8 in the above general formula (5) Polyphosphate ester compound 3: Compound represented by the above general formula (6) Polyphosphate ester compound 4: Compound represented by the above general formula (1), wherein R ¹ , R ³ , R ⁵ , R ⁷ is a hydrogen atom, R ² , R ⁴ , R ⁶ and R ⁸ are alkyl groups having 1 to 20 carbon atoms, R ⁹ is a divalent hydrocarbon group having 2 to 20 carbon atoms, and n is 1 to 8 A compound that is a mixture.
Benzotriazole compound 1: 1,2,3-benzotriazole benzotriazole compound 2: methylbenzotriazole benzotriazole compound 3: 1- [N, N-bis (2-ethylhexyl) aminomethyl] methylbenzotriazole antioxidant Agent: 2,6-di-tert-butyl-4-methylphenol (DBPC)
Acid scavenger: 2-ethylhexyl glycidyl ether antifoaming agent: silicone-based antifoaming agent

As is apparent from the results of the lubricity tests of Examples 1 to 16, the friction coefficient in the sliding portion of the refrigerator is lowered by including both the polyphosphate ester compound and the benzotriazole compound in the refrigerator oil. it can. Further, as is clear from the fact that the ring wear amount is small, the wear resistance is also good.
On the other hand, as shown in Comparative Examples 1 to 16, in the case where the refrigerating machine oil does not contain either one or both of the polyphosphate ester compound and the benzotriazole compound, the wear resistance and the friction coefficient are reduced. Both could not be made good.

Claims (13)

  A refrigerating machine oil comprising a base oil containing an oxygen-containing organic compound, a polyphosphate ester compound, and a benzotriazole compound.   The refrigerating machine oil according to claim 1, wherein the content of the polyphosphate ester compound is 0.01 to 5.0 mass% with respect to the total amount of the refrigerating machine oil.   The refrigerating machine oil according to claim 1 or 2, wherein the content of the benzotriazole-based compound is 0.01% by mass or more based on the total amount of the refrigerating machine oil.   The oxygen-containing organic compound is at least one selected from the group consisting of polyvinyl ethers, polyoxyalkylene glycols, poly (oxy) alkylene glycols, copolymers of monoethers thereof and polyvinyl ethers, and polyol esters. The refrigerating machine oil according to any one of claims 1 to 3. The refrigerating machine oil according to any one of claims 1 to 4, wherein the polyphosphate ester compound is a compound represented by the following general formula (1).


(However, in the formula (1), n represents an integer of 1 to ^10, R 1 to R ⁸ each independently represent a hydrogen atom or an alkyl group having a carbon number of 1 to 20, R ⁹ is 2 carbon atoms 20 represents a divalent hydrocarbon group.) The refrigerating machine oil according to claim 5, wherein R ⁹ in the general formula (1) contains an arylene group. The refrigerating machine oil according to claim 5 or 6, wherein R ⁹ in the general formula (1) is any one of the following general formula (2) and general formula (3).
The refrigerating machine oil according to any one of claims 1 to 7, wherein the polyphosphate compound is at least one selected from the group consisting of compounds represented by the following general formulas (5) and (6). .

(However, in Formula (5), n represents an integer of 1 to 10.)
The refrigerating machine oil according to any one of claims 1 to 8, wherein the benzotriazole-based compound is at least one selected from the group consisting of compounds represented by the following general formulas (7) to (9). .

(In the formula (8), R ¹¹ is a linear or branched alkyl group having 1 to 4 carbon atoms, and a is an integer of 1 to 3. When there are a plurality of R ¹¹ , they may be the same as each other. In formula (9), R ¹² is a linear or branched alkyl group having 1 to 4 carbon atoms, b is an integer of 0 to 3, and R ¹³ is a methylene group or an ethylene group. , R ¹⁴ and R ¹⁵ each independently represent a hydrogen atom or a linear or branched alkyl group having 1 to 18 carbon atoms.)   The composition for refrigerators containing a refrigerant | coolant and the refrigerator oil as described in any one of Claims 1-9.   The composition for refrigerators of Claim 10 in which the said refrigerant | coolant contains the 1 type (s) or 2 or more types selected from the group which consists of a fluorinated hydrocarbon, a carbon dioxide, a hydrocarbon, and ammonia.   The composition for a refrigerator according to claim 10 or 11, wherein the refrigerant contains a saturated fluorinated hydrocarbon compound.   A method for producing refrigerating machine oil, wherein a refrigerating machine oil is obtained by blending at least a polyphosphate ester compound and a benzotriazole compound with a base oil containing an oxygen-containing organic compound.