JP3051673B2 - Ester lubricant - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to ester lubricants, and more particularly to ester oil mixtures useful as refrigeration lubricants.

[0002] Many natural and synthetic substances are known to be useful as lubricants, and their utility in certain applications includes, for example, their stability and viscosity under use conditions, their pour points, and It depends on factors such as their miscibility with the materials to be used with them. Among these known substances are ester oils, such as alkyl alkanoates, alkyl diesters of aliphatic and aromatic dicarboxylic acids, and fatty acid esters of neopolyols.

In refrigeration applications (eg, home or industrial refrigerators, freezers, or air conditioners for buildings, cars, airplanes, and other vehicles), chlorofluorocarbons
Refrigerant (hereinafter, synonymous with refrigerant in this specification)
The term "cryogen" is also used) less ozone than - due to the need to replace with cryogen having a consumption capacity, fluoro hydrocarbons, has been reported to be particularly having a zero ozone consumption capacity 1,1,1,2-
It has become important to find lubricants that are suitable for use with tetrafluoroethane (R-134a). Refrigerating machine oil, which is generally selected until now (following Honmyo
In the detailed description, the term "refrigeration oil"
Lubricants to be used generically, and their synonyms
Mineral oil, which is also used as "refrigerant lubricant" ) cannot be used in this application because of its immiscibility with the refrigerant.

[0004] A refrigerating machine oil composition containing the above ester oil containing fluorohydrocarbons (in the present specification, a refrigerating machine
The term frozen composition is also used as a synonym for oil composition.
That) it is desirable to use as a lubricant in. However, the criteria for lubricants in such compositions are R-1 over the entire temperature range (typically in the range of -40 ° C to 70 ° C) where the composition is subject to exposure in refrigeration equipment.
A weight ratio of fluorohydrocarbon / ester oil that is completely miscible with 34a, and is at least generally believed to be most important with respect to the complete miscibility sought;
That is, when used in an amount that gives 4/1,
Many of these ester oils lack their miscibility.

[0005] International patent application WO 93/13188 (Sab
ahi) teaches ester oils that have excellent miscibility with refrigerants containing R-134a and other fluorohydrocarbons and are useful as lubricants in refrigeration compositions containing them. . These new lubricants _{formula: ROOC-CH 2 CH 2 -} [(ROOC) CHCH 2] m -C
(COOR) _2- [CH ₂ CH (COOR)] _n -CH ₂ CH ₂ C
OOR wherein R represents an alkyl group having 1 to 30 carbon atoms, at least 10% of which is an alkyl group having 1 to 4 carbon atoms;
And m and n each represent 0 or a positive integer such that the sum of m and n in the molecule is 0-30, preferably 0-10.

[0006] Ester oils lacking complete miscibility with fluorocarbons can be used to improve fluorocarbon-miscibility in amounts of the formula ROOC-CH ₂ CH ₂ -[(ROOC) CHCH ₂ ] _m -C
(COOR) _2- [CH ₂ CH (COOR)] _n -CH ₂ CH ₂ C
OOR wherein R represents an alkyl group having 1 to 30 carbon atoms, at least 10% of which is an alkyl group having 1 to 4 carbon atoms;
And each of m and n represents 0 or a positive integer such that the sum of m and n in the molecule is 0 to 30].
It has now been found that greater compatibility with refrigeration agents comprising fluorohydrocarbons is imparted.

[0007] Those freezing agents improved according to the present invention
Miscible ester oils include those that are completely immiscible with the fluorohydrocarbon in any proportion, those that are miscible with the fluorohydrocarbon only when used in very small amounts, and frozen compositions. Those having the desired miscibility only in a part of the temperature range that is likely to be exhibited are included. As mentioned above, these first ester oils of the novel composition are known substances, they are commercially available and sometimes their limited miscibility with fluorohydrocarbons does not harm their use Has been found to be suitable for use in

Most commonly, the first ester oils are oily (1) alkyl alkanoates, (2) alkyl diesters of aliphatic and aromatic dicarboxylic acids, and (3) higher fatty acid esters of neopolyols. And / or mixtures thereof and / or mixtures thereof with ester oils which are themselves miscible with fluorohydrocarbons, the ester oils being immiscible or partially immiscible with the fluorohydrocarbons. Only miscible in nature. However, other ester oils lacking the desired miscibility, such as diol esters and carbonates, can also have their fluorohydrocarbon-miscibility improved by the practice of the present invention.

As is known, alkyl alkanoate oils are compounds in which the alkyl moiety generally has 1-30 carbon atoms, but the alkanoic acid moiety has 1-20 carbon atoms;
In particular, certain alkyl and alkanoic acid moieties which are combined with one another in such compounds are those which render it oily. Typically, the alkyl alkanoates are alkyl groups such as, for example, a hexyl, heptyl, octyl, isooctyl, 2-ethylhexyl, nonyl, decyl, isodecyl, dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, docosyl, tetracosyl, or triacontyl group. Has 6 to 30 carbon atoms, preferably 8 carbon atoms.
-12, and more preferably 8-10. However, when the alkanoic acid moieties contain chains of sufficient length (generally at least 6 carbons) to make the compound oily, they may be, for example, methyl, ethyl, propyl, isopropylbutyl, or pentyl, for example. The compound having a smaller alkyl group may be used. The carbon number of the alkanoic acid portion of these oils is generally 1-20 and includes, for example, formic, acetic, propionic, butyric, pentanoic, hexanoic, heptanoic, octanoic, decanoic, lauric, It may be a myristic, palmitic, stearic, or eicosanoic acid group.

The alkyl diesters may generally have the same or different esterification groups and generally include, for example, butyl, pentyl, hexyl, heptyl,
Octyl, isooctyl, 2-ethylhexyl, nonyl, decyl, isodecyl, dodecyl, tetradecyl, hexadecyl or octadecyl,
18, preferably 8-12, and more preferably 8-
Phthalic acid esters or adipic acid esters, which are alkyl groups of 10. However, other aliphatic and aromatic dicarboxylic acids, such as the corresponding esters of azelaic acid, sebacic acid, isophthalic acid, and terephthalic acid, can also be used.

When a fatty acid ester of a neopolyol is used, it is generally at least one alkanoic acid having 8 to 20 carbon atoms, such as octanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid. Acid or eicosanoic acid) and esters of neopolyols such as pentaerythritol, dipentaerythritol, trimethylolethane, trimethylolpropane, neopentylglycol or other polyhydric alcohols containing at least one quaternary carbon It is. However, the present invention provides that the neopolyol comprises one or more of the above higher alkanoic acids and one or more lower alkanoic acids, such as acetic acid, propionic acid, butyric acid,
Miscibility of neopolyol esters, usually immiscible or only partially miscible with fluorohydrocarbons, including those obtained by esterification with mixtures of pentanoic, hexanoic, and heptanoic acids It is also useful in improving.

The second ester oil used in a miscibility improving amount has the formula ROOC-CH ₂ CH ₂ -[(ROOC) CHCH ₂ ] _m -C
(COOR) _2- [CH ₂ CH (COOR)] _n -CH ₂ CH ₂ C
OOR wherein R represents an alkyl group having 1 to 30 carbon atoms, at least 10% of which is an alkyl group having 1 to 4 carbon atoms;
And m and n each represent 0 or a positive integer such that the sum of m and n in the molecule is 0 to 30]. However, it is preferred that m and n in the molecule
Are oils with an average of 1-10. As noted above, these second ester oils are disclosed in the Sabahi literature.

Essentially, the second ester oil is a compound obtained by reacting a suitable Michael donor and Michael acceptor and then, if desired, subjecting the product to a work-up such as transesterification, or It is a mixture. When produced directly by the Michael reaction, they are prepared by adding one or more dialkyl malonates to one or more acrylic acids, such that the product contains at least the required number of lower alkyl groups. It is synthesized by reacting with alkyl. However, it is also possible to prepare a lubricant by preparing such a Michael product and then subjecting it to a transesterification reaction to replace some of the lower alkyl groups with higher alkyl groups.

The Michael donor and the Michael acceptor which can be used in the reaction include alkyl groups having 1-3 carbon atoms.
All dialkyl malonates and alkyl acrylates that are 0 are included, but (1) those donors that are sufficiently reactive to allow a reasonably rapid reaction are preferred, and (2) Of course, at least a part of the reactants needs to contain an alkyl group having 1 to 4 carbon atoms. The alkyl group in such compounds is preferably a true alkyl group (ie, a saturated aliphatic hydrocarbyl group),
For example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, tetradecyl,
Hexadecyl, octadecyl, eicosyl, docosyl,
Tetracosyl and triacontyl groups, more preferably those having 1 to 10 carbon atoms, and most preferably methyl and / or ethyl groups. However, they are predominantly alkyl groups, ie groups containing one or more atoms (eg oxygen, sulfur or phosphorus atoms) other than carbon and hydrogen of the alkyl group as heteroatoms. And they may be part of a chain or as a substituent (eg, an alkoxy, halo, or cyano group), but with only a small amount such that the predominant hydrocarbyl nature of the group is retained. Contains other atoms.

In order to retain the predominant hydrocarbyl character of the group, the number of heteroatoms or non-hydrocarbyl substituents therein must not exceed 0.3 per carbon atom and preferably Not more than 0.1 per carbon. The term alkyl as used herein refers to the predominant alkyl group as well as to these predominantly alkyl groups, as these predominant hydrocarbyl groups can be considered to be virtually identical to the alkyl groups to which they best correspond. Should be understood to include alkyl groups designated by the term Examples of such groups are chlorohexyl, bromodecyl, ethoxyoctyl, and cyanononyl.

As in Sabahi, basic initiators (preferably hydroxides, alkoxides, amides, or carbonates of alkali or alkaline earth metals) and phase transfer catalysts (preferably alkylammonium salts such as A donor and an acceptor at an appropriate temperature, generally in the presence of chloride, bromide, fluoride, iodide, sulfuric acid, hydrogen sulfate, carbonic acid, and tetraalkylammonium phosphate having an alkyl group having 1-20 carbon atoms. 0-150 ° C, preferably 20-12 ° C
It is generally preferred to produce the Michael product by reacting at 0 ° C, and most preferably at 60-110 ° C.

By combining the reactants, initiator, and catalyst, optionally in the presence of a solvent, and maintaining contact between the reactants at the selected reaction temperature until the desired degree of reaction has occurred, The reaction takes place. In order to obtain better control of the reaction temperature and consequently an improved reaction direction towards the formation of the desired product, it is common to make the Michael acceptor the last component charged into the reaction vessel. Is preferred.

The reaction generally yields a mixture of products containing different numbers of acceptor moieties per molecule, and is theoretically obtained by the amount of acceptor used in the reaction mixture. It allows the production of molecules containing more than a certain number of receptor moieties. However, in order for the product to contain a substantial amount of the desired product molecule, the reaction mixture contains at least the stoichiometrically required amount, and preferably a stoichiometric excess of the receptor. It is necessary to. Therefore, oils having optimal viscosity generally contain an acceptor / donor moiety with a molecular number of 1-30, preferably 1-10, so that the acceptor / donor in the reaction mixture is Body molar ratio is 1-35 / 1, more preferably 1-15 / 1
Is generally preferred. Particularly preferred lubricants of the present invention are ester oils made to have at least three acceptor molecules in at least about 25% of the molecules obtained by the Michael reaction.

The products of the Michael reaction may be liquid or solid, depending on the particular reactants and reactant ratios used, and, as noted above, they typically have different numbers of receptors per molecule. A mixture of compounds containing moieties. If desired, the individual compounds of the mixture or the groups of these compounds (eg the lower and higher molecular weight moieties) can be esterified before their use in their end use or for such use. They may be separated from each other before being exchanged. However, such separation is often unnecessary and in fact sometimes undesirable. Some higher molecular weight moieties are desired to provide the required viscosity, while some lower molecular weight moieties are desired to increase the miscibility of the oil with the refrigerant used therewith. Products that are characterized by a broad molecular weight distribution, such as when used in frozen compositions as described, are advantageous in providing a balance of properties.

To obtain a better balance of properties or properties that are otherwise different from that of the Michael reaction product is to subject the product mixture or one or more of its components to transesterification. Can also be achieved by Such a post-treatment of the Michael product is particularly advantageous in providing a product containing an ester group that relatively slows the reaction if the ester group is present in one or more of the Michael reactants. is there. Thus, for example, dimethyl malonate is reacted with methyl acrylate to give a first product and then this product is transesterified with hexanol to react later dihexyl malonate and methyl acrylate. It is also preferred to produce an oily second product in which about one third of the functional groups are hexyl esters by preparing an oily Michael reaction product.

[0021] Regardless of whether the transesterification is performed on recovered or unrecovered intermediates, one or more containing more carbons per carbon than the alkyl group for which the intermediates are to be exchanged. It does so by contacting the above alcohols and maintaining the contact between the reactants at the appropriate temperature until the desired transesterification has taken place. Most preferred alcohols for use in this reaction are substituted and unsubstituted alkanols having up to 30 carbon atoms (eg, ethanol, chloroethanol, propanol, butanol, hexanol, bromohexanol, heptanol, octanol, decanol, fluorodecanol). Octanol, dodecanol, hexadecanol, octadecanol, eicosanol, tetracosanol, triacontanol, and mixtures thereof), and also contains up to 30 carbon atoms and also contains heteroatoms such as oxygen, phosphorus, or sulfur. Aliphatic alcohols (eg, ethylthioethanol or ethoxyethanol).

The amount of alcohol used in the transesterification reaction depends on the desired degree of transesterification, which is generally a stoichiometric amount or a slight excess over the stoichiometric requirement. Quantity. For example, when the intermediate contains an average of 4 ester groups per molecule and the desired degree of transesterification is 75%, the amount of alcohol added to the intermediate may be 3 moles or a slight excess / Mole intermediate. On the other hand, when the desired degree of transesterification is about 50%, about 2/3 of the alcohol will be added.

As shown in the Sabahi reference, one of the factors that determines the viscosity is the chain length of the alkyl group.
The use of transesterification methods in the manufacture of lubricants is a particularly desirable method for making lubricants with higher viscosities. However, when the alcohol used in this method contains higher alkyl groups, for example alkyls having 6-30 carbon atoms, it is important to avoid substitution of too much lower alkyl groups. Whether the lubricant is produced directly by the Michael reaction or by transesterification of the Michael reaction product, the lubricant must have the desired miscibility with the fluorohydrocarbon cryogen. If so, at least 10%, preferably at least 20%, and more preferably at least 50% of the alkyl groups should contain only 1-4 carbon atoms.

The use of a transesterification reaction after the completion of the Michael reaction allows a wide range of products to be prepared from specific products of the Michael reaction. Transesterification allows reflux and removal of lower alcohol by-products from the reaction mixture in the presence or absence of a basic catalyst without unavoidable loss of one or more higher alcohol reactants from the reaction vessel It is suitably carried out at an elevated temperature such as 50-180 ° C.

The product resulting from the Michael reaction or from the conversion of the Michael reaction product to a transesterified derivative is typically washed with water to remove unreacted materials and catalyst prior to use in their intended use. And, if desired, they may then be further purified by subjecting them to fractional distillation.

The refrigeration lubricant of the present invention is an ester oil mixture comprising a first ester oil and a miscibility improving amount of a second ester oil, which improves the fluorohydrocarbon miscibility of the first oil. The amount of the second oil required for this depends on the degree of miscibility of the first oil itself with the fluorohydrocarbons. Generally, the component oils are used in a ratio to provide a weight ratio of the second ester oil / first ester oil of at least about 0.05 / 1, and this ratio is most commonly at least 0. .1 / 1. The preferred weight ratio of the second ester oil / first ester oil is 0.5-5.0 / 1, more preferably 1-5 / 1.

As is known, (1) the lubricant used with the refrigeration agent is exposed to the temperature range to which the refrigeration composition is exposed, typically a temperature in the range of -40 ° C to 70 ° C or sometimes higher, generally. (2) suitable viscosities for such lubricants are 1-600 at 40 ° C., preferably 5
−300, and most preferably 10-200 mm ² s
^-1 and (3) it is often desirable that the lubricant have a viscosity index of ≧ 100, but (4) the most desirable viscosity for the lubricant will vary depending on factors such as the particular temperature to which it is exposed. However, lower viscosities are most suitable for lubricants used at relatively low temperatures, while higher viscosities are more suitable for lubricants intended for use at relatively high temperatures. Therefore, certain second ester oils that are optimal for blending with the first ester oil to improve its fluorohydrocarbon miscibility can vary depending on the viscosity desired for the lubricant, and a relatively large number of long oils Oils with side chains, relatively high molecular weight, and relatively broad molecular weight distribution are generally the most sticky.

The fluorohydrocarbon refrigerating agents most advantageously used with the novel lubricant mixture are one or more fluorohydrocarbons, such as difluoromethane (R-3
2) 1,1,2,2,2-pentafluoroethane (R-125),
1,1,2,2-tetrafluoroethane (R-134), 1,1,
It is a refrigerating agent composed of 1,2-tetrafluoroethane (R-134a), 1,1,1-trifluoroethane (R-143a), and 1,1-difluoroethane (R-152a). Alternatively, they may comprise one or more fluorohydrocarbons and one or more other cryogens, such as hydrocarbons such as methane, ethane, propane (R-290), butane, ethylene, and propylene, and Halocarbons and / or
Or halohydrocarbons such as chlorotrifluoromethane, dichlorodifluoromethane, dichlorofluoromethane, chlorodifluoromethane (R-22), 1,2,2-trifluoro-1,1,2-trichloroethane, 1,1-dichloro -2,2,2-trifluoroethane (R-123), 1,1-dichloro-1-fluoroethane, 1-chloro-2,2,2-
Trifluoroethane, 1-chloro-1,2,2,2-tetrafluoroethane (R-124), 1-chloro-1,1,2,2-
It may be a mixture with tetrafluoroethane and dichloromethane. Refrigerant formulations in which these lubricants can be advantageously used include binary mixtures of R-32 with R-125, R-152a, or R-134a, as well as R-125 / R-143a, -290 /
R-134a and R-22 / R-152a binary blends, and for example R-2
2 / R-290 / R-125, R-22 / R-152a / R-124, R-32 / R-125 / R-134
a, and ternary formulations such as R-125 / R-143a / R-134a.

The refrigeration compositions of the present invention typically comprise 0.001-1-1, preferably 0.1-1 parts of novel lubricant per part by weight of cryogen, and are desired. If so, they can also contain additives of the type commonly used in refrigeration lubricants. In addition to epoxies and other dehydrating agents that are sometimes used to prevent refrigeration equipment corrosion due to water in the refrigeration composition, such additives include, for example, oxidation resistance and thermal stability improvers, corrosion inhibitors Agent, metal deactivator, lubricity additive, viscosity index improver,
Pour point and / or coalescence point depressants, detergents, dispersants, foam inhibitors, anti-wear agents, and extreme pressure resistant additives, such as those exemplified in US Pat. No. 5,021,179 (Zehler et al.) , Are included. Zehler As in other literature,
These additives, when used, are generally used in small amounts, generally not more than 8%, preferably not more than 5% of the weight of the lubricant formulation.

[0030] The frozen composition is generally prepared before use. However, when desired, they may be manufactured in-situ during operation of the refrigeration system. Therefore, instead of pre-compounding, the refrigeration equipment and lubricant may be charged separately, simultaneously or sequentially in any order.

The present invention relates to a method for improving the fluorocarbon-miscibility of the first ester oil. (1) An ester oil which is completely immiscible with the fluorohydrocarbon contains the fluorohydrocarbon even at a high temperature of 70 ° C. (2) ester oils that are generally miscible only at relatively high temperatures to which the frozen composition is subject to exposure, up to -40 ° C or sometimes This is advantageous in that it can be miscible even at lower temperatures.

The following examples are provided to illustrate the present invention and are not intended to be limiting.
Unless stated otherwise, the amounts given in these examples are by weight.

[0033]

EXAMPLE 1 Example 1 of malonic ester / acrylate ester oil (PBE-25)
A production reactor is charged with 15.8 Kg (120 mol) of dimethyl malonate, 158 g (1.2 mol) of potassium carbonate, and 37 g (0.1 mol) of tetrabutylammonium hydrogen sulfate under nitrogen. The reactor was heated to 70 ° C and 2
5.8 Kg (300 mol) of methyl acrylate are added over 6 hours, and the reaction mixture is then heated to 70-80 ° C. for at least 10 hours to give a major amount of 1,3,3,5-
Tetramethyl esters of pentanetetracarboxylic acid, lesser amounts of pentamethyl and higher esters,
In addition, a product mixture containing a small amount of trimethyl ester of 1,1,3-propanetricarboxylic acid is prepared.

22 kg (296 mol) of n-butanol and 30.3 kg (296 mol) of n-hexanol were charged to the reactor and 11 vol.
Heat to 0-120 ° C. After removal of the stoichiometric amount of methanol, the reaction mixture was cooled to room temperature, diluted with toluene, washed with water until neutral, dried by azeotropic removal of water, and the crude was removed under reduced pressure. Heat treatment.

Reduced pressure (1 mmHg) and 200-250
A distillation at 40 ° C. separates a low-viscosity oil having a viscosity of 17 mm ² s ⁻¹ at 40 ° C. (hereinafter PBE-17) and a bottom product called PBE-25. PBE-25
Is a viscosity of 24.8 mm ² · s ⁻¹ at 40 ° C. and 100 ° C.
, A viscosity index of 4.7 mm ² · s ⁻¹ , a viscosity index of 108,
An oil having a total acid number of 0.034 mg KOH / g, a water content of 73 ppm, and complete miscibility with R-134a over a temperature range from -60 ° C to 80 ° C.

Example 2 4 parts of R-134a are combined with 1 part of an ester lubricant consisting of 1 part of Emkarate DTDA (di-tridecyl adipate sold by ICI) or a mixture thereof with PBE-25 of Example 1. This produces several test compositions. Then R-134a while keeping each temperature for 5 minutes at different temperatures
Test the miscibility of each of the / lubricant formulations. Table I shows the proportions of Emkarate DTDA / PBE-25 used in the manufacture of the lubricants and the results of the tests.

[0037]

[Table 1]

Example 3 Example 2 is repeated except that Emkarate DTDA is replaced by Hatcol 2911, an adipate ester of a mixture of 2-ethylhexanol and isodecanol sold by Hatco Chemical Corp. The percentage of Hatcol 2911 / PBE-25 used in the manufacture of the lubricant and the results of the tests are shown in Table II.

[0039]

[Table 2]

Example 4 Emkarate DTDA was purchased from Hatcol, a di-2-ethylhexyl adipate sold by Hatco Chemical Corp.
Example 2 is repeated except that the replacement is made in 2908. The percentage of Hatcol 2908 / PBE-25 used in the manufacture of the lubricant and the results of the tests are shown in Table III.

[0041]

[Table 3]

Example 5 Emkarate DTDA was purchased from Hatco Chemical Corp. Hatcol 2906, a di-isooctyl adipate.
Example 2 is repeated except for replacing with. The percentage of Hatcol 2906 / PBE-25 used in the manufacture of the lubricant and the results of the tests are shown in Table IV.

[0043]

[Table 4]

Example 6 Example 2 is repeated except that Emkarate DTDA is replaced by Emkarate 911P, a phthalate of a mixture of nonanol and undecanol. Table V shows the proportions of Emkarate 911P / PBE-25 used in the manufacture of the lubricants and the results of the tests.

[0045]

[Table 5]

Example 7 Emkarate DTDA is a Hatmethyl 2938 trimethylolpropane ester of a mixture of fatty acids having 8-12 carbon atoms.
Example 2 is repeated except for replacing with. The proportion of Hatcol 2938 / PBE-25 used in the manufacture of the lubricant and the results of the tests are shown in Table VI.

[0047]

[Table 6]

Example 8 Example 2 is repeated except that Emkarate DTDA is replaced by a butyrate ester of a mixture of dodecanol and octadecanol, designated Butyrate-1218. The proportions of Butyrate-1218 / PBE-25 used in the manufacture of the lubricant and the results of the tests are shown in Table VII.

[0049]

[Table 7]

Example 9 Example 8 is repeated except that PBE-25 is replaced by the lower viscosity oil PBE-17 listed in Example 1. PBE-17 has a viscosity of 17 mm ² · s ⁻¹ at 40 ° C.,
3.6 mm ² · s ⁻¹ viscosity at 100 ° C., 0.025
mg KOH / g total acid number, 64 ppm water content,
And R-134a over the temperature range of -60 ° C to 80 ° C
It is an oil having complete miscibility with The proportions of Butyrate-1218 / PBE-17 used in the manufacture of the lubricant and the results of the tests are shown in Table VIII.

[0051]

[Table 8]

The main features and aspects of the present invention are as follows.

1. (A) Lack of complete miscibility with fluorocarbons and alkyl alkanoates, alkyl diesters of dicarboxylic acids, neopolyol esters, diol esters, and carbonate esters of C8-20 fatty acids first ester oil comprises at least one ester selected from the group consisting of, and (B) a fluorohydrocarbon - formula ROOC-CH ₂ in an amount to improve the miscibility CH ₂ - [(ROOC) CHCH ₂ ] _m- C
(COOR) _2- [CH ₂ CH (COOR)] _n -CH ₂ CH ₂ C
OOR wherein R represents an alkyl group having 1 to 30 carbon atoms, at least 10% of which is an alkyl group having 1 to 4 carbon atoms;
And each of m and n represents 0 or a positive integer such that the sum of m and n in the molecule is 0-30]. Wherein the fluorohydrocarbon-miscibility improving amount of the second ester oil is sufficient to provide a second ester oil / first ester oil weight ratio of at least about 0.05 / 1. Is a lubricant.

2. The lubricant of claim 1, wherein the ratio is at least 0.1 / 1.

3. (2) wherein the ratio is 0.5-5.0 / 1;
Lubricant.

4. The lubricant of the above item 3, wherein the ratio is 1-5 / 1.

5. The sum of m and n in the molecule is 1-
10. The lubricant according to 1 above, which is 10.

6. The above 5), wherein at least 20% of the alkyl groups of the second ester oil contain 1-4 carbon atoms.
Lubricant.

7. (A) Lack of complete miscibility with fluorocarbons as refrigeration lubricants, and alkyl alkanoates, alkyl diesters of dicarboxylic acids, and neodies of C8-20 fatty acids A first ester oil comprising at least one ester selected from the group consisting of polyol esters, diol esters, and carbonate esters; and (B) a fluorohydrocarbon-miscible amount of a formula. _{ROOC-CH 2 CH 2 - [} (ROOC) CHCH 2] m -C
(COOR) _2- [CH ₂ CH (COOR)] _n -CH ₂ CH ₂ C
OOR wherein R represents an alkyl group having 1 to 30 carbon atoms, at least 10% of which is an alkyl group having 1 to 4 carbon atoms;
And each of m and n represents 0 or a positive integer such that the sum of m and n in the molecule is 0-30]. The fluorohydrocarbon-miscibility improving amount of the second ester oil is sufficient to provide a weight ratio of the second ester oil / first ester oil of at least about 0.05 / 1. A frozen composition comprising a lubricant.

8. The composition of claim 7, wherein the ratio is at least 0.1 / 1.

9. The ratio is 1-5 / 1, at least 20% of the alkyl groups of the second ester oil contain 1-4 carbon atoms, and the sum of m and n in the molecule averages 1-10 8. The composition according to 8 above.

10. 1,1,
The composition according to any one of the above 7-9, which is 1,2-tetrafluoroethane.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kenneth Karl Rilgier 48942 Midland Utd Point Rain Number 2 1607 in Michigan, USA 1607 (72) Inventor Mahmoud Sabahi 70810 Button Rougeille Shadwalk Drive, Louisiana, USA 851 (56) References Table 7-507048 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C10M 105/36-105/46 C10N 40:30

Claims (2)

(57) [Claims] 1. (A) Alkyl alkanoates, alkyl diesters of dicarboxylic acids, fatty acids having 8 to 20 carbon atoms which lack complete miscibility with fluorocarbons in the range of -40 ° C. to 70 ° C. A first ester oil comprising at least one ester selected from the group consisting of neopolyol esters, diol esters, and carbonates, and (B) a fluorohydrocarbon-miscible-improving amount. of formula _{ROOC-CH 2 CH 2 - [} (ROOC) CHCH 2] m -
_{C (COOR) 2 - [CH} 2 CH (COOR)] n -CH 2 C
H ₂ COOR wherein R represents an alkyl group having 1 to 30 carbon atoms, at least 10% of which is an alkyl group having 1 to 4 carbon atoms;
And each of m and n represents 0 or a positive integer such that the sum of m and n in the molecule is 0-30]. there are, the fluorohydrocarbon - lubrication second ester oil in an amount to improve the miscibility is sufficient to provide a weight ratio of at least 1/1 of the second ester oil / first ester oil Agent. 2. Fluorohydrocarbon refrigerants and (A) as refrigeration oils which lack complete miscibility with fluorocarbons in the range of -40 ° C. to 70 ° C. and have alkyl diesters of alkyl alkanoates and dicarboxylic acids. , A first ester oil comprising at least one ester selected from the group consisting of neopolyol esters, diol esters, and carbonates of fatty acids having 8 to 20 carbon atoms; and (B) fluorohydrocarbon - amount of a compound of formula _{ROOC-CH 2 CH} 2 to improve the miscibility _{- [(ROOC) CHCH 2]} m -
_{C (COOR) 2 - [CH} 2 CH (COOR)] n -CH 2 C
H ₂ COOR wherein R represents an alkyl group having 1 to 30 carbon atoms, at least 10% of which is an alkyl group having 1 to 4 carbon atoms;
And each of m and n represents 0 or a positive integer such that the sum of m and n in the molecule is 0-30]. A lubricant wherein the fluorohydrocarbon-miscibility improving amount of the second ester oil is sufficient to provide a weight ratio of at least 1 : 1 second ester oil / first ester oil A refrigerating machine oil composition comprising: