JPS6019352B2 - Refrigerating machine oil composition - Google Patents

Description

[Detailed description of the invention] The present invention relates to a refrigerating machine oil composition.

More specifically, the present invention relates to a refrigerating machine oil composition that is thermally and chemically stable in the presence of halogen-based cooling fluids and has a high degree of lubricity. Refrigerating machine oil is a lubricating oil used in refrigerators, and of course it requires a high level of lubricity, but since it is used in the presence of special cold soot called halogen compounds, halogen-based refrigerants It is also required to be thermally and chemically stable in the presence of.

Regarding the required properties and test methods for refrigeration oil, see Watanabe (Nisseki Review "9'4"), 146-
160) or Hirasawa (Nisseki Review, 1 [3', 1 spot to 1 total), and the general description is as follows.

'1} Must have an appropriate viscosity as a lubricating oil.

[2) Excellent low temperature performance; low pour point and flock point (wax precipitation temperature). '3}
Low critical melting temperature with cold air.

However, depending on the application, such as high viscosity oil, the critical melting temperature may not be a problem. '4} Excellent in the shield tube test; Even when exposed to high temperatures in the coexistence of halogen-based soot and metals, it does not change color, does not generate precipitates, and does not cause copper plating (Cu plating). That there is no.

(5' Thermal stability, for example, excellent in panel coking test.

Conventionally, mineral oils, especially naphthene-based ones, have been widely used as base oils for refrigeration oils, and these mineral oil-based refrigeration oils are described in, for example, Taruko Sho 40-11940 and JP-A-Sho 4
6-4532, and Megaku Sho 49-47498.

On the other hand, regarding synthetic oils, alkyl aromatic oils, alkylnaphthene oils, polyolefin oils, silicone bottles, etc. are being considered.Refrigerating machine oils based on these synthetic oils include, for example, Tsubaki Kimiaki 49-14107, Hakama Kimiaki 49 -13
483, Tsubaki Kimishō 49-13829 Tsubaki Kimishō 49-1908
4 Tsubaki-ko Sho 51-37647, special public Shou 51-4501, special Seki Sho 48-600, Hakama-batsu Sho 49-34903, tokukai-sho 49
-97351, and Tokkan Sho 51-22971. On the other hand, regarding additives used in refrigerating machine oil, according to the descriptions in the above patent publications and published patent publications, antioxidants of substituted phenols, aromatic amines, and metal salts, sulfur-based, phosphorus-based, organic Metal-based and combination oil improvers, antifoaming agents such as silicone oil, various metal deactivators, and dehydrochlorination agents such as epoxide, as well as halogenated aromatics such as chlorinated biphenyls, Polymethacrylate and the like are known as additives.

However, although conventional refrigeration oils made from known combinations of these base oils and additives satisfy some of the above-mentioned required properties, they do not have excellent performance in all of them, especially in the sealed tube test and No one has yet been developed that achieves sufficient results in actual machine tests.

An object of the present invention is to provide a refrigerating machine oil composition that satisfies all of the required properties {1} to '5' above and has sufficient performance even in actual machine tests.

The composition of the present invention comprises a key oil-based or synthetic oil-based lubricating oil having a viscosity of 20 to 15 ratio St at 37.8°C, and a glycidyl ether type epoxy compound and
A refrigerating machine oil composition comprising 0.1 to 1% by weight of at least one additive selected from the group consisting of epoxidized fatty acid monoesters. For example, the above-mentioned Japanese Patent Laid-Open No. 491-97351 discloses that a dehydrochlorination agent such as epoxide is added to refrigerating machine oil. JP-A-49-97351 discloses an invention in which a branched alkylbenzene having a limited structure is used as a refrigerating machine oil.The feature of this invention is its compatibility with halogen-based refrigerants. However, the invention does not specify what type of dehydrochlorination agent is effective;
Furthermore, the relationship between the type of dehydrochlorination agent and performance other than lacquer properties, or the amount of dehydrochlorination agent added, has not been clarified. In other words, there are many types of epoxides that are generally used as dehydrochlorination agents, such as condensates of epichlorohydrin and bisphenol, epoxy compounds of cyclohexene, epoxidized vegetable oils, and epoxidized fatty acid esters that can be used as vinyl chloride. Among them, epoxy q vegetable oil is particularly widely used (Akiba et al., "Polymer Processing" Extra Issue 9 Epoxy Resin, 259-2). In addition to epoxides, other dehydrochlorination agents such as inorganic acid salts, metal soaps, organic tin compounds, and amino compounds are known, and among them, organic tin compounds are said to be particularly effective. Pinyru chloride, its chemistry and industry -
10, pp. 114-130, Asakura Shoten). In addition, the Tokuko Showa 3
6-8926 has up to 4 or 12 substituents
An example is shown in which a lubricating oil to which 2 parts by weight of an aryl glycide ether having an alkyl group containing 1 or more carbons is used as a diesel engine oil.
Group 6 does not mention the cold soot machine oil that uses halogen cold soot, and furthermore does not disclose anything about the performance of this lubricating oil under the special conditions of the presence of a halogen coolant.

On the other hand, US Pat. No. 3,459,660 discloses a refrigerating machine oil containing an organotin compound, but this organotin compound, which is known as a dehydrochlorination agent, alone cannot provide an excellent refrigerating machine oil.

As a result of examining these various dehydrochlorinating agents as additives for refrigerating machine oil, the inventors of the present application found that refrigerating machine oil containing epoxidized vegetable oil, an epoxy compound of cyclohexene, and an inorganic dehydrochlorinating agent was tested in a shield tube test. In contrast, glycidyl ether type epoxy compounds and epoxidized fatty acid compounds cannot exhibit sufficient performance.
It has been found that esters are extremely effective as additives.

In the refrigeration oil composition of the present invention, the additive used is at least one compound selected from the group consisting of '11 glycidyl ester' type epoxy compounds and [2' epoxidized fatty acid monoesters.

Examples of the glycidyl ether type eboxy compound include phenyl or alkyl phenyl glycidyl ether, and a condensate of epichlorohydrin and bisphenol.

The alkyl phenyl glycidyl ether mentioned here is
It has 1 to 8 C4-C,8 alkyl groups, and preferably one has one C5-C,o alkyl group. As the condensate of epichlorohydrin and pisphael, for example, those obtained by condensing bisphenol A and epichlorohydrin in an alkaline solution are preferable, and these are manufactured by Shell Chemical Co., Ltd. , Ciba-Geigy Araldite, Dow DER
It is commercially available under trade names such as Epotak (manufactured by Reichhold), Junox (manufactured by UCC), and Adeka Resin (manufactured by Asahi Denka). As epoxidized fatty acid monoester,
Epoxidized C,2-C2.

Examples include esters of fatty acids and C, to C8 alcohols or phenols and alkylphenols, especially butyl, hexyl, benzyl, cyclohexyl, methoxyethyl, octyl, phenyl, and tert-butyl phenyl esters of epoxystearic acid. These include, for example, Adeka Sizer D-40 manufactured by Adeka Argus,
50.9 rear Adeka Argus Dravex 3.3
, 4.2, Eposizer W-12 manufactured by Dainippon Ink Chemical Co., Ltd.
It is commercially available under trade names such as 1.128.131.180 and Kapotsu 4 manufactured by Kao Soap Co., Ltd. The blending amount of these additives is 0.1 to 1% cloud content based on the total amount of the composition.
, particularly preferably 0.5 to 3% by weight. If the amount is less than this range, the effect of addition will not be sufficient, and if it exceeds this range, there will be no significant improvement in the effect, which is rather unfavorable from an economic standpoint. In the refrigerating machine oil composition of the present invention, the base oil preferably used is 20 to 15 ratio St in 37.800.
lubricating oil, or a mixture thereof, with a viscosity of .

Mineral oil-based lubricating oils include lubricating oil fractions of naphthenic or dewaxed paraffinic mineral oils, or nuclear hydrides of highly aromatic components obtained by cracking petroleum, with a boiling point of 2.
Examples include those having a molecular weight of 50 to 380 oo, and lubricating oil fractions of naphthenic mineral oils are particularly preferred. Synthetic lubricants include linear furkylbenzene, branched alkylbenzene, and polyQ.
Examples include olefin oil, alkylnaphthalene, ester oil, and polyglycol oil. The term "linear alkylbenzene" as used herein refers to one whose main component is straight mirror alkylbenzene, and which has a viscosity of 20 to 15 ratio St at 37.8 oo.For example, it is produced as a by-product as a child alkylate during alkylation of benzene with n-olefin. You can use whatever you want. This virgin alkylate contains about 50% alkylbenzene and about 45% two-ring hydrocarbons, and is preferably subjected to hydrorefining or clay treatment if necessary.
In addition, branched alkylbenzene is a branched alkylbenzene that has a viscosity of 20 to 15 ratio S at 37.8 qo.
For example, those created as heavy alkylates during alkylation of benzene with propylene tetramer can be used. This virgin alkylate contains about 90% alkylbenzene, and is preferably treated with clay if necessary. Poly Q-olefin oil refers to one obtained by homopolymerizing or copolymerizing at least one Q-olefin having 4 to 14 carbon atoms, preferably 8 to 1 carbon atoms, and has a viscosity of 20 to 15 at 37.8°C and a ratio St of 20 to 15. For this purpose, an average molecular weight of 300 to 600 is preferable. As ester oils, esters of dibasic acids and monohydric alcohols, such as di-2-ethylhexyl sebacate, and polyhydric alcohol esters, such as trimethylolpropane tricaprylate, can be used.

As the polyglycol oil, polyalkylene glycol and its mono- or dialkyl ether can be used, and polyethylene-propylene glycol, polypropylene glycol, or C,
~C4 ethers are preferred. A particularly preferred polyglycol oil is polypropylene glycol monobutyl ether. Among these synthetic lubricating oils, linear and branched alkylbenzenes are particularly preferred.

In the refrigerating machine oil composition of the present invention, a particularly preferred base oil has a viscosity of 20 to 15 ratio St at 37.8 qo.

It is at least one selected from the group consisting of naphthenic mineral oil, linear alkylbenzene, and branched alkylbenzene, and a mixture can of course be used. In the present invention, a more preferable composition is a mineral oil-based or synthetic oil-based lubricating oil having a viscosity of 20 to 15 ratio St at 37.8 qo, a glycidyl ether type epoxy compound, and a '21 epoxy compound. At least one additive selected from the group consisting of fatty acid monoesters.
1 to 10% by weight, and [C' formula (wherein R is C, ~C20 alkyl group, n is 0 to 2
) A penzotriazole metal deactivator represented by 0.
001 to 0.05% by weight.

This is a refrigerating machine oil composition for a refrigerating machine that uses a halogen-based refrigerant. It is known that a metal deactivator is added to refrigerating machine oil, and for example, the above-mentioned Japanese Patent Laid-Open No. 49-97351 describes alizarin, quinizarin, Schiff's base (azomethine), alkyl sulfide, zinc-dithiocarbamate, and merka. Ptidebenzothiazoles are disclosed.

Many types of such metal deactivators are known, but the present inventors found that bewazotriazole type ones are effective, and in particular, the glycidyl ether type adpoxy compounds mentioned above. It was discovered that when used in combination with epoxidized fatty acid monoester, it exhibited excellent performance in various tests including the shield tube test. In the refrigeration oil composition of the present invention, the metal deactivator used is penzotriazole and its alkyl derivative represented by the following formula.

(In the formula, R is an alkyl group of C, ~C2o, and n is not 0.) A preferred metal deactivator is a metal deactivator in which R is an alkyl group of C, ~C, o, and n is 0 to 2. Particularly preferred are compounds of the formula, among which penzotriazole, methylbenzotriazole, dimethylbenzotriazole and ethylbenzotriazole.

The amount of metal deactivator added is 0.0 based on the total amount of the composition.
01 to 0.05% by weight, particularly 0.005 to 0.02% by weight.

If the amount added is less than this range, the addition effect will not be sufficient, and if it exceeds this range, there will be no significant effect.
From an economic standpoint, this is actually undesirable. In the refrigerating machine oil composition of the present invention, conventionally known refrigerating machine oil additives,
For example, it is also possible to add antioxidants, oiliness improvers and antifoaming agents.

The refrigerating machine oil composition of the present invention is effective for refrigerating machines that use halogen cold soot.

The halogen-based cold soot referred to here is nonflammable cold soot in which hydrocarbons are replaced with chlorine or fluorine, and a representative example is Freon, which is commercially available from DuPont in the United States under the trade name Freon. Freon 11, 12, 13, 22, 1
Examples include 13114, 50, and 502, and among these, the refrigerating machine oil of the present invention is effective for refrigerators using Freon 12 or 22. Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

The base oil and additives used are as follows. (
Direct mirror alkylbenzene: Quantitative alkylate created when benzene is alkylated with n-olefin (weight of alkylbenzene 5%, total amount of alkylindane and alkyltetralin is 10% by weight, alkylhydroacenaphthene is about 8% by weight, about 4% by weight alkylnaphthalene, and the remainder polycyclic aromatic compounds.

) is hydrorefined using a nickel-molybdenum catalyst and then treated with white clay. 2matsu St @37.8 0.

Branched alkylbenzene: a young alkylate produced when benzene is alkylated with propylene tetramer (alkylbenzene 8a% by weight, total amount of alkylindanes and alkyltetralins is 1% by weight, and the remainder is polycyclic aromatic) Consists of compounds.

) treated with Hakushi. 4 Father St @37. is 0. Naphthenic mineral oil: Refined product.

11 Sha St @37. is 0.

<Additives> Glycidyl ether A: Phenyl glycidyl ether B: Nonyl phenyl glycidyl ether/C: Pisphenol A epichlorohydrin condensate (Epon 812 manufactured by Shell) Epoxidized fatty acid monoester: Octyl epoxy stearate (Adeka Argus) Dravex 3.2) Epoxidized vegetable oil: Soybean oil ester (Adekasizer ○-13 fertilizer, manufactured by Adeka Argus) Epoxy compound of cyclohexene: 1.2 Epoxycyclohexene butyl tin maleate: (Stanclair T-157, manufactured by Nippon Interstub) Metal deactivator> Penzotriazole Zn dithiocarbamate: (Vanlube AZ manufactured by Panderbilt) Mercaptobenzothiazole: (Vanluv 601 manufactured by Panderbilt) <Test method and required properties as refrigerating machine oil> Seal tube test: Oil and An equivalent amount of alkyl refrigerant (R-12 or R-22) is sealed together with a catalyst (iron or iron-copper) in a glass tube, and the degree of discoloration is measured after heating at 175 oo for a predetermined time.

Change when dark brown is 8 and colorless is 0 It is preferable that the chromaticity is 4 or less. Delicious.

Also, check the condition of precipitates or Cu plating. Attend the event.

Pour point: Preferably -22.5q0 or less.

Flock point: Oil 1 ship volume % and cold butterfly (R-12 or
R-22) A mixture of 9% by volume is cooled and the maximum temperature at which the wax component precipitates is measured.

It is preferable that it is -30 oo or less.

Critical melting temperature: Cool mixtures of oil and media (R-12 or R-22) at various mixing ratios, and measure the temperature at which two-layer separation begins, and take the highest value.

Thermal stability: JIS standards for turbine oil applied mutatis mutandis. Passed if there is no sludge precipitation in 170oo x 24 hours.

Actual machine test: A commercially available refrigerator was operated continuously for 150 feeding hours. After operation, the refrigerator was disassembled and the state of the Cu plating was observed.

Examples 1 to 5 and Comparative Examples 1 to 7 Examples 1 to 5 are refrigerating machine oil compositions according to the present invention, in which glycidyl ether or epoxidized fatty acid monoester is blended with various base oils.

All showed excellent performance in various tests including the shield tube test. Comparative Example 1 uses naphthenic mineral oil as an additive, and has a large blue color in the shield tube test.

Comparative Examples 2 to 4 are compositions in which various dehydrochlorination agents such as epoxidized vegetable oil, cyclohexene epoxy compound, or dibutyltin maleate are blended into naphthenic iron kettles, and these compositions are superior to additive-free oils in the shield tube test. Although it does, the oil deteriorates over time,
Cannot withstand long-term use. Comparative Example 5 is a composition containing only penzotriazole, but the metal deactivator alone has almost no effect.

Comparative Examples 6 to 7 are compositions in which metal deactivators such as Zn dithiocarbamate, mercapto, and benzothiazole are added to the composition of Example 3. It tends to impair the performance in the machine oil shield tube test and cannot be used effectively.

Examples 6 to 11 Examples 6 to 9 are compositions in which glycidyl ether or epoxidized fatty acid monoester is blended as an additive with branched alkylbenzene, and penzotriazole is further blended as a metal deactivator. It showed excellent performance in various tests including the shield tube test.

Examples 10 to 11 were compositions in which glycidyl ether or epoxidized fatty acid monoester was blended as an additive to branched alkylbenzene, and exhibited performances second to those of Examples 4 to 8.

Claims (1)

[Scope of Claims] 1 (A) A mineral oil-based or synthetic oil-based lubricating oil having a viscosity of 20 to 150 cSt at 37.8°C, and (
B) For refrigerators using halogen-based refrigerants, comprising 0.1 to 10% by weight of at least one additive selected from the group consisting of (1) glycidyl ether type epoxy compounds and (2) epoxidized fatty acid monoesters. Refrigerating machine oil composition. 2 (A) Mineral or synthetic lubricating oil having a viscosity of 20 to 150 cSt at 37.8°C, (B)
(1) Glycidyl ether type epoxy compound and (2
) 0.1 to 10% by weight of at least one additive selected from the group consisting of epoxidized fatty acid monoesters, and (C) Formula ▲ Numerical formula, chemical formula, table, etc. Alkyl group, n is 0
A refrigerating machine oil composition for a refrigerating machine using a halogen-based refrigerant, comprising 0.001 to 0.05% by weight of a benzotriazole metal deactivator represented by 2).