JPH0445194A - Lubricating oil for refrigerator using fluorocarbon as refrigerant - Google Patents

Abstract

PURPOSE:To obtain the title lubricating oil consisting of a compound obtained by reacting an alkylene oxide adduct of polyhydric alcohol and polyhydric phenol with an organic chloride and having compatibility enough to 'Fron R-134a(R)' which is a refrigerant (especially at high temperature). CONSTITUTION:The objective lubricating oil consisting of a compound having 300-1,500 average molecular weight and expressed by the formula I and/or formula II (R1 is 4-30C polyhydric alcohol residue or polyhydric phenol compound residue; R2 is 1-20C alkylating agent residue; R3 and R4 are 2-8C alkylene; R5 is 2-20C polyvalent carboxylic acid residue; R6 is 1-20C monovalent carboxylic acid residue; (m), (n), (m') and (n') are integers of 0-50 and are not simultaneously 0; (p) and (q) are integer of 2-6). Furthermore, the compound expressed by formula I is excellent in compatibility with fluorocarbon, heat resistance, viscosity index or resistance to hydrolysis, and the compound expressed by formula II is especially excellent in compatibility with fluorocarbon, fluidity at low temperature, electric characteristics, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lubricating oil (hereinafter referred to as refrigeration machine oil) for a compressor of a refrigeration machine that uses Freon as a refrigerant.

In particular, 1,1,1,2-tetrafluoroethane (hereinafter R-
134a), 1,1 difluoroethane (hereinafter referred to as R-
152a) is used as a refrigerant.

[Prior Art] Currently, fluorocarbons containing chlorine as a constituent element, such as trichloromonofluoroethane (hereinafter referred to as R-
11) and dichlorodifluoromethane (hereinafter referred to as R-1
2) is used.

However, it has become clear that when these fluorocarbons, which contain chlorine as a constituent element, are released into the atmosphere, they contribute to ozone layer depletion and global warming, promoting so-called global environmental pollution and destruction. It has become.

For this reason, a worldwide movement is emerging to suppress the production and consumption of so-called specific fluorocarbons including R-11 and R-12. Accordingly, studies are underway to replace the refrigerant used in household refrigerators, room air conditioners, and car air conditioners with chlorine-free refrigerants, such as R-134a and R-152a. Therefore, there is currently a desire to develop a new refrigeration oil suitable for these refrigerants.

On the other hand, many mineral oil-based and synthetic oil-based oils are known as conventional refrigeration oils, but mineral oil-based oils include R-134a and R-
Synthetic oils are not compatible with 152a, and synthetic oils are being studied as new refrigerating machine oils.

An example of conventionally known synthetic oil is polyether-based synthetic oil, which is described in Oil Chemistry, Vol. 29, No. 9,
pp. 336-343 (I980) and Peterotek, Vol. 8, No. 6, pp. 562-566 (I985)
as outlined in. Examples of patents for synthetic oils include JP-A-57-63395, JP-A-59-117590, JP-A-61-281199, and JP-A-1-2.
59093, JP 1-259094, JP 1-259095, JP 1-271491
JP-A-2-41392, etc.

However, these conventional oils are R-134a and R-152a.
It has become clear that there are drawbacks to using refrigeration oil as a refrigerant. That is, conventional refrigeration oil is particularly R-134.
The compatibility with A and R-152a is insufficient, and there are also problems with lubricity and heat resistance, so at present we have not seen the emergence of a refrigerating machine oil with sufficient performance for practical use. .

[Problems to be Solved by the Invention] The purpose of the present invention is to solve the above-mentioned drawbacks of conventional refrigerating machine oils, such as compatibility with fluorocarbons, lubricity, and heat resistance. As R-134a and R-15
It is an object of the present invention to provide a refrigerating machine oil which has extremely good compatibility when using 2a and has excellent lubricity and heat resistance.

[Means for Solving the Problems] The present inventors have conducted intensive research on various mineral oils and synthetic oils in order to solve the above problems. The present invention was found to be effective in achieving the objective, and the present invention was completed.

That is, the present invention provides a household electric refrigerator, a room air conditioner, or a car air conditioner, which has an average molecular weight of 300 to 15 oO and is characterized by being a single compound or a mixture of compounds represented by the following general formulas (I) and (II). Regarding refrigerating machine oil.

R1[O(R3O)m(R4O)nR2]p...
-(I) However, R1: a polyhydric alcohol residue or a polyhydric phenolic compound residue having 4 to 30 carbon atoms.

R2: Monovalent organic chloride residue having 1 to 20 carbon atoms.

R8, R4: Alkylene group having 2 to 8 carbon atoms.

R6: polyhydric carboxylic acid residue having 2 to 2 carbon atoms.

R1: Monovalent carboxylic acid residue having 1 to 2 carbon atoms.

m, n, m, n: Integer from O to 50 (however, m and n
, m and n are never O at the same time, m+n, m'
+n' is an integer from 1 to 5o respectively) p, q: 2 to
It is an integer of 6.

Among the compounds related to the present invention, the compound represented by (I) in the above-mentioned shipyard is obtained by adding an alkylene oxide to a polyhydric alcohol or/and a polyhydric phenolic compound in the presence of an alkali. , can be obtained by reacting an organic chloride using Williamson's reaction. Representative examples of polyhydric alcohols, polyhydric phenolic compounds, organic chlorides, and alkylene oxides used here are shown below.

Typical examples of polyhydric alcohols: neopentyl glycol, penzonorbornacy 3-
6-diol, Spiroglycol, Butanediol,
・Cyclohexane dimetatool, ・1,6-hexanediol, ・Propanediol, ・Salicyl alcohol,
・Decanediol, ・Pinacol, ・2-ethyl-1,
3-hexanediol, 1,4-dichloro-2,3-
Alcohols such as butanediol, 2-methyl-2,4,-bentanediol, glycerin, butanetriol, trimethylolpropane, glyceric acid, pentaerythritol, adonitol, gluconic acid, mannitol, etc. Compounds having two or more OH groups in the molecule can be used alone or in a mixture of two or more.

Front side of polyhydric phenolic compounds: Bisphenol A, biphenyldiol, oxydiphenyl, resoldinol, butylhydroquinone, bromohydroquinone, 4-tert-butylpyrocatechol, dichlorohydroquinone, catechol, naphthalene Diol, ・chlorohydroquinone, ・dihydrogythiacetophenone, ・dihydroxybenzoic acid, hexylresorcinol, ・hydroquinone, hydroxybenzoic acid, ・hydroxy-2-naphthoic acid, ・
Methylhydroquinone, ・Methylresorcinol, ・Phenylpyrocatechol, ・Protocatechuic acid, ・Tetrachlorohydroquinone, ・Tetrachloropyrocatechol,
・Pyrogallol, methylpyrogallol, ・5-sec-
Phenolic compounds such as butylpyrogallol, benzenetetrol, inositol, resorsillic acid, etc.
A compound having two or more H groups or a compound having a carboxyl group in addition to the phenolic ○H group can be used alone or in a mixture of two or more.

Typical examples of organic chlorides include methyl chloride, ethyl chloride, butyl chloride, amyl chloride, isopropyl chloride, hebutane chloride, chlorinated decane, chloromethylbutane, chloromethylpropane, etc. Below, organic chlorides which react with alcoholic OH groups can be used alone or in mixtures.

Typical example of alkylene oxide ・Ethylene oxide, ・Propylene oxide.

Alkylene oxides such as butylene oxide, styrene oxide, etc. can be used alone or in a mixture of two or more.

Furthermore, among the compounds according to the present invention, the compound represented by the general formula (n) is generally prepared by adding an alkylene oxide to a polyvalent carboxylic acid in the presence of an alkali, and then converting the compound into an ester with a monovalent carboxylic acid. It can be obtained by converting still,
A similar compound can be obtained by adding an alkylene oxide to a -valent carboxylic acid in the presence of an alkali, and finally subjecting a polyvalent carboxylic acid to an esterification reaction.

Representative examples of the polyvalent carboxylic acid, -valent carboxylic acid, and alkylene oxide used to obtain the compound represented by the general formula (II) are shown below.

Representative polycarboxylic acids: acetylene dicarboxylic acid, terephthalic acid, hydroxyphthalic acid, camphoric acid, adipic acid, azelaic acid, cyclohexic acid dicarboxylic acid, fumaric acid,
Succinic acid (or succinic anhydride), glutaric acid, malonic acid, methylcaptosuccinic acid, methylphthalic acid,
Maleic acid (or maleic anhydride), ・1,2,3.6
'-Tetrahydrophthalic acid, pimelic acid, sebacic acid, lactic acid, salicylic acid, chlorosalicylic acid, bromosalicylic acid, dichlorosalicylic acid, malic acid,
Citric acid, mucic acid, shikimic acid, pyromellitic acid,
Compounds having two or more carboxyl groups, such as tartaric acid and oxalic acid, or compounds having a phenolic OH group or an alcoholic OH group in addition to the carboxyl group, may be used alone or in a mixture of two or more.

Typical examples of monovalent carboxylic acids: Acetic acid, Adamantane acetic acid, Naphthalene acetic acid, Monochloroacetic acid, Ethoxyacetic acid, Diphenylacetic acid,
Dichloroacetic acid, bromoacetic acid, benzoic acid, bromobenzoic acid, hexylbenzoic acid, benzoic acid, butoxybenzoic acid, butylbenzoic acid, chlorobenzoic acid, dichlorobenzoic acid, dimethoxybenzoic acid, methoxybenzoic acid Acid, ・Ethoxybenzoic acid, ・Hexyloxybenzoic acid, valeric acid, ・Behenic acid, ・Quinolinecarboxylic acid, Proline,
・Acetic acid, ・Cyclohexylbutyric acid, ・Bromobutyric acid, ・Flomo-3-methylacetic acid, ・Heptafluorobutyric acid, ・Phenylbutyric acid, ・Propionic acid, ・Bromopropionic acid, ・3
-chloro-2,2'-dimethylpropionic acid, ・chloropropionic acid, ・mercaptopropionic acid, ・pentafluoropropionic acid, ・bromohexadecanoic acid, ・bromoundecanoic acid, ・undecanoic acid, ・heptanoic acid, hexic acid,・Lauric acid, ・Levulinic acid, ・2-methylhexic acid, ・Myristic acid, ・Nonanoic acid, octanoic acid, ・Palmitic acid, ・Anisthane, anthracenecarboxylic acid,
・Butylcyclohexanecarboxylic acid, ・Cumic acid, ・Cyclohexanecarboxylic acid, ・Decanoic acid, ・2-ethylhexanoic acid, ・Heptadecanoic acid, ・Naphthoic acid, ・Hydratropic acid, ・Toluic acid, ・Pivalic acid, ・Propylcyclohexane Compounds having one carboxyl group such as carboxylic acid, picric acid, pipecolic acid, etc. can be used alone or in a mixture of two or more.

Typical examples of alkylene oxides include ethylene oxide, propylene oxide, butylene oxide, and styrene oxide, which can be used alone or in a mixture of two or more.

The refrigerating machine oil according to the present invention has the general formula (I) or (I
The compound represented by I) may be used alone or as a mixture thereof. Therefore, the compounds represented by the general formulas (I) and (II) can be synthesized separately and used by mixing them in a blending ratio that suits the desired performance.

In addition, from the standpoint of increasing productivity, general formulas (I) and (I
It is also possible to carry out mixtures of compounds of I) in the synthesis stage.

For example, a mixture of polyhydric alcohol and polyhydric carboxylic acid in the desired ratio is used as a starting material, alkylene oxide is added to this in the presence of an alkali, further esterified with monohydric carboxylic acid, and finally organic chloride is added. The desired refrigerating machine oil can be obtained by carrying out the etherification.

In this case, it is important to keep the alkylene oxide addition temperature low in the initial stage, preferably at 90 to 120°C. If the reaction temperature here is set to 130° C. or higher, an esterification reaction between the polyhydric alcohol and the polyhydric carboxylic acid will occur, and the desired compound may not be obtained, so care must be taken.

The refrigerating machine oil according to the present invention has the above general formulas (I) and (I1).
Although the compounds represented by can be used alone, they may be mixed in order to impart particularly desired properties.

The compound represented by general formula (I) has excellent compatibility with fluorocarbons, heat resistance, viscosity index, or hydrolysis resistance, and the compound represented by general formula (II) has excellent compatibility with fluorocarbons, It has particularly excellent low-temperature fluidity and electrical properties.

When blending the compounds represented by general formulas (I) and (II), it is important that the effect of the blending is substantially observed. Therefore, although the blending ratio is not fixed, (I)
Compound / Compound (■) = 90-10/10-90 (
wt ratio) is - boat fishing.

(Production Example) Although the method for producing the refrigerating machine oil according to the present invention is not limited to a specific production method, the method for producing the refrigerating machine oil according to the present invention, which was used as a test oil in the Examples, will be described below.

Production Example-1 Production side for the compound of general formula (I) 800m1 equipped with a stirrer, alkylene oxide inlet, raw material inlet, N2 gas inlet, thermometer, pressure gauge, and heater.
2. Add 40g of glycerin and 0.0g of caustic potassium to an autoclave.
8 gr, and the air inside the autoclave was sufficiently replaced with N2 gas while maintaining the autoclave at room temperature.

Thereafter, the temperature inside the system was raised to 140°C, and then ribropylene oxide (277g) was introduced through the inlet over a period of about 2.5 hours, and the mixture was further aged at 135 to 140°C for about 2 hours.

During this time, the pressure inside the system was 1.5 to 7 Kg/cm''.Next, the temperature was lowered to 30'C, sealed with N2 gas, and caustic soda (55 g) was poured into the system while avoiding air intrusion. After charging, the temperature was raised to 130° C. again, and butyl chloride (30 g) was introduced from the inlet over a period of about 8 hours.

The liquid obtained here (490 g) was filtered and by-produced sodium chloride (88 g r) was separated and removed to obtain a refrigerating machine oil (383 g) according to the present invention.

Production example-2 - Production example of the compound of Funagura (II) Production example-1
Manufactured using the same autoclave. Prepare adipic acid (I, 10gr) and caustic potash (I, 2gr), keep the air at room temperature, and keep the air inside the autoclave sufficiently N! Replaced with gas.

After that, the inside of the system was heated to 130°C, and propylene oxide (340g) was introduced into it over a period of about 4 hours, and further,
It was aged for about 2 hours at the same temperature. During this time, the pressure in the system is 1.5~
8.1Kg/cm".

Next, after returning the inside of the system to atmospheric pressure, benzoic acid (I84gr.
) and caustic potash (2gr) and raise the system temperature to 180'.
The temperature was increased to c. During the reaction, N2 gas (3Q/min) was blown into the reactor to promote dehydration.

The obtained liquid (593gr) was filtered to remove insoluble phosphates to obtain a refrigerating machine oil according to the present invention.

Manufacturing example-3 It was produced using the same autoclave as Production Example-1.

Glycerin (32,3g r), adipic acid (57,6
(g r) and caustic potash (I, 5 g r) were charged, and the air in the autoclave was sufficiently replaced with N and gas while maintaining the autoclave at room temperature.

Thereafter, the temperature inside the system was raised to 105° C., and ribropylene oxide (I50 g) was introduced through the inlet over a period of about 5 hours. At this stage, most of the adipic acid is in a state where propylene oxide has been added, so the temperature inside the system is set to 135.
No reaction between glycerin and adipic acid occurs even if the temperature is raised to ℃.

Therefore, propylene oxide (250 g) was further introduced over a period of about 2 hours while the temperature inside the system was maintained at 135° C., and the mixture was incubated at that temperature for about 2 hours. The pressure during this time is 2.1 to 9.
4 K g/cm”. Then benzoic acid (
96.4g r) and caustic potash (4gr) were added while sealing with N2 gas, and the temperature inside the system was raised to 180°C.
Furthermore, in order to promote the dehydration reaction, N, gas (2.7Q/m
in) was injected. This esterification reaction was carried out under atmospheric pressure and took about 7 hours. Next, the temperature inside the system was lowered to 35°C, and caustic soda (46 g r) was added while sealing with N gas.
was added, the temperature was raised to 130°C, and butyl chloride (I00gr) was introduced from the inlet over a period of about 6 hours. The obtained liquid (694gr) was filtered and the by-produced sodium chloride component (75gr) was separated and removed to obtain a refrigerating machine oil (606gr) according to the present invention.

In addition, Production Examples (4 to 15) were produced using the same autoclave as Production Examples (I to 3) and by the same production method.

Table 1 shows the raw materials and product properties of the refrigerating machine oils obtained in Production Examples (I-15).

(Example) The effects of the refrigerating machine oil according to the present invention will be specifically explained using the refrigerating machine oil produced in the production examples (I to 15) shown in Table 1 as test oils.

Compatibility: In order to measure the compatibility between the refrigeration oil and refrigerant according to the present invention, 1 gr of sample oil and 1 gr of refrigerant (R-134a) are sealed in a glass tube and cooled and heated to a temperature at which two-phase separation occurs. (two-phase separation temperature) was measured.

Blow in lubricating refrigerant (R-134a) (60m Q/m
in), the Farex seizure load was measured while keeping the atmosphere constant.

In order to evaluate the chemical stability at high temperatures, test oil 1 was used.
．． After sealing 5gr and metal M (iron, copper, aluminum) in a glass tube, the hue was measured after testing at 175°C for 10 days. At the same time, the presence or absence of sludge generation was confirmed.

The results of each of the above tests are shown in Table 2.

[Effects of the Invention] As explained above, the refrigerating machine oil according to the present invention has sufficient compatibility with Freon R-134a, which is a refrigerant, and has excellent compatibility particularly at high temperatures. Judging from this point of view, it turned out to be a very well-balanced refrigeration oil.

Therefore, the product of the present invention has been found to be effective as a refrigerating machine oil that uses new fluorocarbons such as R-134a as a refrigerant, and is also effective in reducing the use of regulated fluorocarbons, which are attracting worldwide attention. It also has a large contribution to make.

Patent applicant: Toho Chemical Industry Co., Ltd.

Claims (1)

[Scope of Claims] A lubricating oil for refrigerators using fluorocarbons as a refrigerant, characterized by having an average molecular weight of 300 to 1,500 and being a compound represented by the following general formulas (I) and (II), either alone or as a mixture. . R_1[O(R_3O)m(R_4O)nR_2]p・
...(I)▲There are mathematical formulas, chemical formulas, tables, etc.▼...
(II) However, R_1: a polyhydric alcohol residue or a polyhydric phenolic compound residue having 4 to 30 carbon atoms. R_2: Monovalent organic chloride residue having 1 to 20 carbon atoms. R_3, R_4: Alkylene group having 2 to 8 carbon atoms. R_5: polyhydric carboxylic acid residue having 2 to 20 carbon atoms. R_6: Monovalent carboxylic acid residue having 1 to 20 carbon atoms. m, n, m', n': An integer from 0 to 50 (however, m, n, m
' and n' are never 0 at the same time, m+n, m'+
n' is an integer from 1 to 50, respectively) p, q: 2 to 6
is an integer.