JPH09279175A - Ester lubricant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a lubricant suitable for the use in a refrigerant composition containing a fluorohydrocarbon.

SOLUTION: An ester lubricant having improved miscibility with a fluorohydrocarbon refrigerant is produced by compounding an ester oil free from complete miscibility with fluorocarbons with a 2nd ester oil composed of a molecule expressed by formula ROOC-CH₂CH₂-[(ROOC)CHCH₂]_m-C (COOR)₂-[CH₂CH(COOR)]_n-CH₂CH₂COOR [R is a 1-30C alkyl; at least 10% of the R group is a 1-4C alkyl; (m) and (n) are each 0 or a positive integer; the sum of (m) and (n) in the molecule is 0-30].

COPYRIGHT: (C)1997,JPO

Description

Detailed Description of the Invention

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

Many natural and synthetic materials are known to be useful as lubricants, and their utility in particular applications is, for example, their stability and viscosity under the conditions of use, their pour points, and It depends on factors such as their miscibility with the substances to be used with them. Among these known materials 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, automobiles, airplanes, and other vehicles), chlorofluorocarbon cryogens have less ozone-consuming ability. Due to the need to replace with a cryogen, fluorohydrocarbons, especially 1,1,1,2-tetrafluoroethane (R-134, a cryogen reported to have an ozone consumption capacity of 0.
It has become important to find a suitable lubricant for use with a). Mineral oil, which is the refrigeration lubricant that has hitherto been generally selected, cannot be used in this application because of its immiscibility with the refrigeration agent.

It would be desirable to be able to use the above ester oils as lubricants in frozen compositions containing fluorohydrocarbons. However, the criteria for lubricants in such compositions are that the composition is completely miscible with R-134a over the entire temperature range in which the composition is susceptible to exposure in refrigeration equipment (typically in the range of -40 ° C to 70 ° C). Is used, and at least is used in such an amount to give the fluorohydrocarbon / ester oil weight ratio, ie, 4/1, which is generally believed to be the most important for the complete miscibility to be obtained. In many cases, many of these ester oils lack their miscibility.

International patent application WO 93/13188 (Sab
ahi) teaches ester oils that have excellent miscibility with refrigeration agents 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 [In the formula, 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 an oil or a molecule corresponding to 0 or a positive integer such that the sum of m and n in the molecule is 0-30, preferably 0-10.

An ester oil lacking complete miscibility with fluorocarbons will have a fluorohydrocarbon-miscibility improving amount 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 [In the formula, 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] by blending with an ester oil consisting of a molecule corresponding to
It has now been found that greater miscibility with freezing agents comprising fluorohydrocarbons is imparted.

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

Most commonly, the first ester oil is an oily (1) alkyl alkanoates, (2) alkyl diesters of aliphatic and aromatic dicarboxylic acids, and (3) higher fatty acid esters of neopolyols. And mixtures thereof and / or their mixtures with ester oils which are themselves miscible with fluorohydrocarbons, these ester oils being immiscible or partially immiscible with fluorohydrocarbons. Only miscible. 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 this invention.

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

The alkyl diesters may generally have the same or different esterifying groups and are generally for example butyl, pentyl, hexyl, heptyl,
It has a carbon number of 4 such as octyl, isooctyl, 2-ethylhexyl, nonyl, decyl, isodecyl, dodecyl, tetradecyl, hexadecyl, or octadecyl groups.
18, preferably 8-12, and more preferably 8-
Phthalates or adipates, 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 neopolyol is used, it is generally at least one C8-20 alkanoic acid (eg octanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, stearin). Acid or eicosanoic acid) with a neopolyol, such as pentaerythritol, dipentaerythritol, trimethylolethane, trimethylolpropane, neopentyl glycol, or other polyhydric alcohols containing at least one quaternary carbon. Is. However, the present invention provides neopolyols with one or more of the above higher alkanoic acids and one or more of the lower alkanoic acids such as acetic acid, propionic acid, butyric acid,
Miscibility of neopolyol esters that are usually immiscible or only partially miscible with fluorohydrocarbons, including those obtained by esterification with mixtures of pentanoic acid, hexanoic acid, and heptanoic acid Is also useful for improving.

The second ester oil used in a miscibility improving amount is 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 [In the formula, 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]. However, it is preferably m and n in the molecule.
Is an oil having an average of 1-10. As noted above, these second ester oils are disclosed in the Sabahi reference.

In essence, the second ester oil is a compound obtained by reacting a suitable Michael donor and Michael acceptor and then subjecting the product to a post-treatment such as transesterification if desired. It is a mixture. When made directly by the Michael reaction, they are one or more dialkyl malonates selected so that the product contains at least the required number of lower alkyl groups and one or more acrylic acid. 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 Michael acceptor which can be used in the reaction have an alkyl group having 1-3 carbon atoms.
All dialkyl malonates and alkyl acrylates that are 0 are included, but (1) a donor that is sufficiently reactive to allow a reasonably rapid reaction is preferred, and (2) Of course, at least a part of the reaction product 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 are more preferred, those with 1-10 carbon atoms, and most preferred are methyl and / or ethyl groups. However, they are predominantly alkyl groups, ie groups containing one or more atoms other than the carbon and hydrogen of the alkyl group (eg oxygen, sulfur or phosphorus atoms) as heteroatoms. May also be part of the chain or as a substituent (eg, an alkoxy, halo, or cyano group), provided that the minor hydrocarbyl nature of the group is retained. Contains other atoms.

In order to retain the predominant hydrocarbyl nature 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. As these predominant hydrocarbyl groups can be considered to be virtually the same as the alkyl groups to which they best correspond, the term alkyl as used herein refers to the predominant alkyl group as well as these groups in general. It is to be understood to include alkyl groups represented by the term. Examples of such groups are chlorohexyl, bromodecyl, ethoxyoctyl, and cyanononyl.

As in the Sabahi reference, basic initiators (preferably alkali or alkaline earth metal hydroxides, alkoxides, amides or carbonates) and phase transfer catalysts (preferably alkyl ammonium salts, eg The donor and acceptor are added in the presence of chlorinated, brominated, fluorinated, iodinated, sulfuric acid, hydrogensulfate, carbonic acid, and tetraalkylammonium phosphate having an alkyl group having 1 to 20 carbon atoms at a suitable temperature, generally. 0-150 ° C, preferably 20-12
It is generally preferred to produce the Michael product by reacting at 0 ° C, and most preferably 60-110 ° C.

By combining the reactants, the initiator, and the 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 is carried out. 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 for the Michael acceptor to be the last component loaded into the reaction vessel. Is preferable.

Since the reaction generally produces a mixture of products containing different numbers of acceptor moieties per molecule, it can be theoretically obtained by the amount of acceptor used in the reaction mixture. It allows the production of molecules that contain more than the expected number of acceptor moieties. However, in order for the product to contain a substantial amount of the desired product molecule, the reaction mixture must contain at least a stoichiometrically required amount, and preferably a stoichiometric excess of receptor. It is necessary to. Therefore, oils with optimum viscosities generally contain 1-30, preferably 1-10, acceptor / donor moieties with a number of molecules, so that the acceptor / donor in the reaction mixture Body molar ratio is 1-35 / 1, more preferably 1-15 / 1
Is generally preferred. A particularly preferred lubricant of the present invention is an ester oil made to have at least 3 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 acceptors per molecule. It is a mixture of compounds containing moieties. Esters, if desired, of the individual compounds of the mixture or the groups of these compounds (eg the relatively low and relatively high molecular weight moieties) before or in preparation for their end use. They may be separated from each other before being exchanged. However, such separation is often unnecessary and in practice is sometimes undesirable. Some relatively high molecular weight moieties are desired to provide the required viscosity, while some relatively lower molecular weight moieties are desired to increase miscibility with the cryogen with which the oil is used. Products characterized by a broad molecular weight distribution, such as when used in such frozen compositions, 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 Post-treatment of such a Michael product is particularly advantageous in providing a product containing ester groups which will relatively retard the reaction if the ester groups are present in one or more of the Michael reactants. is there. Thus, for example, dimethyl malonate is reacted with methyl acrylate to give the first product and then this product is transesterified with hexanol to dilute the slower reacting dihexyl malonate and methyl acrylate. It is also preferred to produce an oily Michael reaction product to provide an oily second product in which about 1/3 of the functional groups are hexyl esters.

Whether or not transesterification is carried out on the recovered or unrecovered intermediate, one or more containing more carbon per alkyl than the alkyl group to which the intermediate is to be replaced. This is done by contacting the above alcohols and maintaining contact between the reactants at a suitable temperature until the desired transesterification has taken place. The 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, fluorodeca). Nols, dodecanols, hexadecanols, octadecanols, eicosanols, tetracosanols, triacontanols, and mixtures thereof), and up to 30 carbon atoms and also containing heteroatoms such as oxygen, phosphorus, or sulfur Aliphatic alcohols such as ethylthioethanol or ethoxyethanol.

The amount of alcohol used in the transesterification reaction depends on the degree of transesterification desired, which amount is generally in a slight stoichiometric amount or slightly in excess of the stoichiometric requirement. Is the amount. 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 is 3 moles or a slight excess of moles. Must be / mol 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 viscosity is the chain length of the alkyl group,
The use of transesterification processes in the production of lubricants is a particularly desirable method for producing lubricants with higher viscosities. However, when the alcohol used in this method contains a higher alkyl group, such as an alkyl having 6 to 30 carbon atoms, it is important to avoid substitution of too much lower alkyl group. Whether the lubricant is produced directly by the Michael reaction or by transesterification of the Michael reaction product, the lubricant has 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 transesterification reactions after the completion of the Michael reaction allows a wide range of products to be produced from specific products of the Michael reaction. Transesterification allows the 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. 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 catalysts prior to their use in their intended use. And may be further purified by subsequent fractional distillation if desired.

The refrigeration lubricant of the present invention is an ester oil mixture containing 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 second oil needed to do so will vary depending on the degree of fluorohydrocarbon miscibility of the first oil itself. Generally, the component oils are used in proportions 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. It is 1/1. The preferred weight ratio of second ester oil / first ester oil is 0.5-5.0 / 1, more preferably 1-5 / 1.

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

The fluorohydrocarbon refrigeration agents most advantageously used with the novel lubricant mixtures 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 freezing agent composed of 1,2-tetrafluoroethane (R-134a), 1,1,1-trifluoroethane (R-143a), and 1,1-difluoroethane (R-152a). Alternatively, they may be one or more fluorohydrocarbons and one or more other refrigerating agents such as hydrocarbons such as methane, ethane, propane (R-290), butane, ethylene and propylene, and Halocarbons and /
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 may be used to advantage include binary mixtures of R-32 and R-125, R-152a, or R-134a, as well as R-125 / R-143a, R-125a. -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 composition of the present invention typically comprises 0.001-1, preferably 0.1-1 part of the new lubricant per part by weight of the refrigeration agent, and is 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 corrosion of refrigeration equipment by water in frozen compositions, such additives include, for example, oxidation resistance and heat stability improvers, corrosion inhibitors. Agent, metal deactivator, lubricity additive, viscosity index improver,
Pour point and / or freezing point depressants, detergents, dispersants, antifoams, 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,
When used, these additives are generally used in small amounts, generally not more than 8%, preferably not more than 5% by weight of the lubricant formulation.

Frozen compositions are generally manufactured prior to use. However, if desired, they may be manufactured in situ during operation of the refrigeration system. Therefore, instead of pre-compounding, the refrigerating agent and the lubricant may be charged to the refrigerating apparatus separately, simultaneously or sequentially in either order.

The present invention provides that the fluorohydrocarbon-miscibility of the first ester oil is (1) an ester oil that is completely immiscible with the fluorohydrocarbon, even though it has a high temperature of 70 ° C. Ester oils that are improved to the extent that they can actually be used as lubricants in frozen compositions and (2) are generally miscible only at relatively high temperatures to which the frozen compositions are exposed to -40 ° C or sometimes It is advantageous in that it can be miscible at lower temperatures.

The following examples are given to illustrate the present invention and are not intended to limit it.
Unless otherwise noted, the amounts listed in these examples are by weight.

[0033]

Example 1 Example 1 of malonic ester / acrylic ester oil (PBE-25)
A manufacturing reaction vessel is charged under nitrogen 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 hydrogensulfate. Heat the reactor to 70 ° C., 2
5.8 Kg (300 mol) of methyl acrylate was added over 6 hours and then the reaction mixture was heated to 70-80 ° C for at least 10 hours to give a major amount of 1,3,3,5-.
Tetramethyl ester of pentane tetracarboxylic acid, lower amounts of pentamethyl and higher esters,
And a product mixture containing a small amount of the 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 the volatiles were collected at the top 11
Heat to 0-120 ° C. After removing 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 product under reduced pressure. Heat treatment.

Reduced pressure (1 mmHg) and 200-250
Distillation at ℃ separates a low viscosity oil having a viscosity of 17 mm ² · s ^-1 at 40 ℃ (hereinafter referred to as PBE-17) and a bottom product called PBE-25. PBE-25
Is a viscosity of 24.8 mm ² · s ^-1 at 40 ° C, 100 ° C
Viscosity of 4.7 mm ² · s ⁻¹ , 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 of -60 ° C to 80 ° C.

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

[0037]

[Table 1]

Example 3 Example 2 is repeated except that the Emkarate DTDA is replaced with Hatcol 2911, an adipic ester of a mixture of 2-ethylhexanol and isodecanol sold by Hatco Chemical Corp. The proportion 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 is di-2-ethylhexyl adipate sold by Hatco Chemical Corp. Hatcol.
Example 2 is repeated except that 2908 is substituted. The proportion 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 Emcolate DTDA is a di-isooctyl adipate sold by Hatco Chemical Corp. Hatcol 2906.
Example 2 is repeated except that it is replaced with. The proportion 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 with Emkarate 911P, which is the phthalate ester of the mixture of nonanol and undecanol. The percentage of Emkarate 911P / PBE-25 used in the manufacture of the lubricant and the results of the tests are shown in Table V.

[0045]

[Table 5]

Example 7 Emkarate DTDA is a trimethylolpropane ester of a mixture of fatty acids having 8 to 12 carbon atoms, Hatcol 2938.
Example 2 is repeated except that it is replaced 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 the Emkarate DTDA is replaced with the butyrate ester of a mixture of dodecanol and octadecanol called Butyrate-1218. The ratio 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 with PBE-17, the lower viscosity oil listed in Example 1. PBE-17 has a viscosity of 17 mm ² · s ^-1 at 40 ° C,
Viscosity of 3.6 mm ² · s ^-1 at 100 ° C, 0.025
a total acid number of mg KOH / g, a water content of 64 ppm,
And R-134a over the temperature range of -60 ℃ to 80 ℃
It is an oil that is completely miscible with. The ratio 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 of C 8-20 fatty acids, diol esters, and carbonates 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 [In the formula, 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], which is a lubricant containing a second ester oil consisting of a molecule corresponding to Wherein 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. Is a lubricant.

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

3. The above 2 in which the ratio is 0.5-5.0 / 1.
Lubricant.

4. The lubricant according to 3 above, wherein the ratio is 1-5 / 1.

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

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

7. Fluorohydrocarbon freezing agents, as well as lacking complete miscibility with (A) fluorocarbons as refrigerating lubricants, and alkyl alkanoates, alkyl diesters of dicarboxylic acids, neo of fatty acids of 8-20 carbon atoms A first ester oil comprising at least one ester selected from the group consisting of polyol esters, diol esters, and carbonic acid esters, and (B) a fluorohydrocarbon-miscible improving formula. _{ROOC-CH 2 CH 2 - [} (ROOC) CHCH 2] m -C
_{(COOR) 2 - [CH 2} CH (COOR)] n -CH 2 CH 2 C
OOR [In the formula, 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], which is a lubricant containing a second ester oil consisting of a molecule corresponding to And 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 7 above, 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 is on average 1-10. The composition of 8 above.

10. Fluorohydrocarbon freezing agent is 1, 1,
The composition according to any of 7-9 above, which is 1,2-tetrafluoroethane.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kenneth Karl Lillier 48642 Midland Woods Point Rain Number 2 1607 (72) Inventor Mamoud Sabahi 70810 United States Louisiana United States Baton Rouge Yuya Cyad Walk Drive 851

Claims (2)

[Claims] 1. (A) Lack of complete miscibility with fluorocarbons and alkyl alkanoates, alkyl diesters of dicarboxylic acids, neopolyol esters of C 8-20 fatty acids, diol esters , And a first ester oil comprising at least one ester selected from the group consisting of carbonates, and (B) a fluorohydrocarbon-miscible improving amount 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 [In the formula, 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], which is a lubricant containing a second ester oil consisting of a molecule corresponding to Wherein 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. Is a lubricant. 2. Lack of complete miscibility with fluorohydrocarbon refrigerating agents and (A) fluorocarbons as refrigerating lubricants and alkyl alkanoates, alkyl diesters of dicarboxylic acids, 8-20 carbon atoms. A first ester oil comprising at least one ester selected from the group consisting of neopolyol esters of fatty acids, diol esters, and carbonic acid esters, and (B) fluorohydrocarbon-miscibility the amount of formula ROOC-CH ₂ CH ₂ to improve _{- [(ROOC) CHCH 2]} m -C
_{(COOR) 2 - [CH 2} CH (COOR)] n -CH 2 CH 2 C
OOR [In the formula, 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], which is a lubricant containing a second ester oil consisting of a molecule corresponding to And 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.