DE102009015873A1 - Refrigerator oil composition, useful in refrigerator, in which carbon dioxide is used as refrigerant, comprises synthetic oil in combination with base oil, where the synthetic oil contains a phosphorus compound as phosphate ester - Google Patents

Abstract

Refrigerator oil composition comprises synthetic oil in combination with base oil, where the synthetic oil contains at least a type of phosphorus compound as phosphate ester.

Description

TECHNICAL AREA

The The present invention relates to a refrigerator oil composition, in particular a refrigerator oil composition for a carbon dioxide refrigerant in which a phosphorus-based antifriction agent with a base oil, containing a synthetic oil is mixed.

STATE OF THE ART

In More recently, the replacement of refrigerants and the increase the efficiency of cooling systems due to destruction ozone layer and global warming drawn. A change of chlorine-containing coolants, such as CFCs (chlorofluorocarbons) or HCHFCs (chlorofluorocarbons), to HFCs (fluorocarbons) was promoted. The However, HFC refrigerants are also subject to global restrictions Warming restrictions, which is why the application of natural coolants, such as carbon dioxide, Ammonia or hydrocarbons was considered.

Along with the ongoing trend to replace chlorine-containing refrigerants or HFC refrigerants with natural refrigerants, refrigeration oils have been developed using alternative refrigerants. Since the oil for refrigerators must have various properties such as lubricity, compatibility with the refrigerant, thermal and hydrolytic resistance, and low hygroscopicity, a compound satisfying these requirements is required depending on the type or applications of the refrigerant. For example, in a refrigerating machine in which an HFC refrigerant, namely 1,1,1,2-tetrafluoroethane (R124a), is used as the refrigerant, polyethylene glycol or the like (see FIG. Japanese Laid-Open Publication 8-311472 ) is used as the base oil, or a phosphate ester-based extreme-pressure-resistant agent is compounded to improve the abrasion resistance (see, for example, U.S. Pat. Japanese Patent Publication 2002-97486 ).

A smaller amount of the extreme pressure resistant agent however, reacts with sliding parts, and the abrasion resistance is lower in a chiller, in the carbon dioxide is used as a coolant, as in a refrigerating machine, in the R134a is used when a refrigerator oil with the same extreme pressure resistant agent is mixed on a phosphate ester basis. That's why it's in a chiller in which carbon dioxide is used as a coolant, to develop a refrigerator oil that with a against extreme pressure resistant agents with a higher Abrasion resistance can be mixed as a phosphate ester and the required properties, such as lubricity, compatibility with the coolant, thermal and hydrolysis resistance and low hygroscopicity.

SUMMARY OF THE INVENTION

aim the present invention is the provision of a refrigerator oil, that with a resistant to extreme pressure means with a higher abrasion resistance than a phosphate ester mixed is and the required properties, such as lubricity, Compatibility with the coolant, thermal and hydrolysis resistance and low hygroscopicity in a well-balanced state, in a refrigerating machine, in which carbon dioxide is used as a coolant.

The Inventors of the present application have found that this Goal by mixing a resistant to extreme pressure Based on phosphorous acid ester, an ionic phosphorus-containing liquid, etc., which a higher reactivity than one against extreme Pressure-resistant agent based on phosphate esters and a base oil containing a polyoxyalkylene glycol a polyol ester, etc. can be achieved.

The present invention of this application (hereinafter also referred to as "present Embodiment "refers to a refrigerator oil composition for a refrigerating machine, in which carbon dioxide as Coolant is used, the refrigerator oil composition contains a base oil that is made from a synthetic oil is composed of at least one other phosphorus compound as a phosphate ester.

The refrigerating machine composition of the present invention is blended with an extreme pressure resistant agent having a higher abrasion resistance than a phosphate ester, the oil for a refrigerating machine using carbon dioxide as a refrigerant having the required properties such as Lubri has compatibility with the coolant, thermal and hydrolysis resistance and low hygroscopicity in a well-balanced state.

BRIEF DESCRIPTION OF THE DRAWING

1 Fig. 12 is a drawing explaining a closed HFFR (Radio Frequency Reciprocating Structure) burn test apparatus used for evaluation of the refrigerator oil composition of the present invention.

LONG DESCRIPTION

To a preferred example of the refrigerator oil composition according to the present embodiment the phosphorus compound is at least one compound selected from Group consisting of a metal salt of an inorganic phosphoric acid, an amine salt of an inorganic phosphoric acid, a Esters of phosphorous acid (i.e., a phosphite), a Metal salt of an organic phosphorous acid, a Amine salt of an organic phosphorous acid and a phosphoric ionic liquid selected is. These phosphorus compounds can be combined of two or more, but preferably only one is used.

To another preferred example of the refrigerator oil composition according to the present embodiment the phosphorus compound is at least one compound selected from Group consisting of esters of phosphorous acid, selected is. The esters of phosphorous acid can be combined of two or more, but preferably only one is used.

To Another preferred example of the refrigerator oil composition according to the present embodiment the ester of phosphorous acid is at least one compound, those selected from the group consisting of triphenyl phosphite, trioctyl phosphite, Dibutyl phosphite, triethyl phosphite, tributyl phosphite, tridecyl phosphite, Trilauryl phosphite, diphenyl phosphite and dilauryl phosphite is.

To Another preferred example of the refrigerator oil composition according to the present embodiment the ester of phosphorous acid is at least one compound, those from the group consisting of triphenyl phosphite, trioctyl phosphite and dibutyl phosphite.

Farther These phosphorous acid esters can be combined of two or more, but preferably only one is used.

To Another preferred example of the refrigerator oil composition according to the present embodiment the phosphorus compound is at least one compound selected from Group consisting of phosphorus-containing ionic liquids is selected. The phosphorus-containing ionic liquids are tri-, n-butyl-methylphosphonium dimethyl phosphate, 1-butyl-3-methyl-imidazolium phosphoric acid, Trihexyl (tetradecyl) phosphonium decanoic acid and the like.

To Another preferred example of the refrigerator oil composition according to the present embodiment is the phosphorus-containing ionic liquid tri-n-butyl-methylphosphonium dimethyl phosphate.

To Another preferred example of the refrigerator oil composition according to the present embodiment the content of the phosphorus compound is 0.1 to 3% by weight. A particularly preferred content of the phosphorus compound is 0.3 to 3 wt .-%. Under the content of the phosphorus compound understands the weight% content of the phosphorus compound, based on the total weight of the refrigerator oil composition.

To Another preferred example of the machine oil composition according to the present embodiment The synthetic oil is at least one oil that from the group consisting of polyoxyalkylene glycols and polyol esters selected in combination of two or more, however, preferably as a compound can be used.

The compounds represented by the following general formula (1) are exemplified as polyoxyalkylene glycols. R ¹ -O- (AO) m R ² (1).

R ¹ and R ² independently represent a hydrogen atom or a C ₁ -C ₈ hydrocarbon group. The compound in which both R ¹ and R ^{2 are} methyl groups is preferred. R ¹ and R ² may be the same or different. "A" means a C ₂ -C ₈ alkylene group, preferably a C ₃ alkylene group. "M" means an integer of 1 or more. When "m" is 2 or more, plural "m" may be the same or different.

As the polyol ester, the esters of a diol or polyol having 3 to 20 hydroxyl groups and a C ₆ to C ₂₀ fatty acid are preferably used. Examples of diols include ethylene glycol, neopentyl glycol, 1,3-propanediol, propylene glycol, 1,4-butanediol and the like.

Examples for polyols include trimethylolethane, trimethylolpropane, Trimethylolbutane, pentaerythritol, dipentaerythritol and the like. Examples for fatty acids include caproic acid, enanthic acid, Caprylic acid, pelargonic acid, capric acid, oleic acid, Isopentanoic acid, 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-ethylhexanoic acid, 3,5,5-trimethylhexanoic acid and like ..

According to another preferred example of the refrigerator oil composition according to the present embodiment, the kinematic viscosity of the base oil at a temperature of 100 ° C is 2 to 50 mm ² / s.

Alternatively, the present invention may be carried out as follows:
In addition to the above-mentioned polyoxyalkylene glycols and polyol esters, as the base oils for the refrigerator oil compositions according to the present invention, for example, the following synthetic oils may be used: alkylbenzenes, alkylnaphthalenes, poly-alpha-olefins, polyvinyl ethers, polyvinyl ether-polyalkylene glycol copolymers, polycarbonates, etc.

additionally to the above-mentioned esters of phosphorous acid For example, the esters of phosphorous acid in the refrigerator oil compositions of the invention tricresyl phosphite, tri (nonylphenyl) phosphite, Tri (2-ethylhexyl) phosphite, triisooctyl phosphite, diphenyl isodecyl phosphite, Tristearyl phosphite, trioleyl phosphite, dipentyl phosphite, dihexyl phosphite, Diheptyl phosphite, dioctyl phosphite, dinonyl phosphite, didecyl phosphite, Diundecyl phosphite, didodecyl phosphite, dioleyl phosphite, dicresyl phosphite, Tripentyl phosphite, trihexyl phosphite, triheptyl phosphite, trinonyl phosphite, Triundecyl phosphite, tridodecyl phosphite, etc.

EXAMPLES

The The present invention is further illustrated by the following examples explained but not limited to this.

EXAMPLES 1-34

The Evaluations of the refrigerator oil compositions according to the invention were performed according to the following procedures

(1) Closed HFRR (Radio Frequency Reciprocation Rig) Abrasion Test.

Using a HFFR (Radio Frequency Reciprocation Rig) Abrasion Test Device (available from PCS Instruments), the test device became 2 in a closed chamber 1 installed as it is in 1 is shown. The abrasion tests were performed using the test device 2 under the following conditions: the load is 2 N; the frequency is 20 Hz; the stroke is 1 mm; the period is 60 minutes; the amount of the test oil is 2 cm ³ ; the temperature of the test oil is 60 °; the test atmosphere is CO ₂ (the CO ₂ from the source of CO ₂ 4 fed and through the rotary pump 5 was released); the pressure of the atmosphere was 0.1 MPa; the ball is a ball made of SUJ2 with a diameter of 6 mm; and the plate 7 is a plate made from SUJ2. Each abrasion test was carried out using the test oil 3 carried out by addition of the phosphorus compounds shown in Table 1 to the base oil, ie polypropylene glycol monomethyl ether, in each case in the amounts of phosphorus compounds shown in Table 1 was prepared. The surface of the plate obtained after the abrasion test 6 was measured by measuring the size, ie a corresponding diameter of one on the surface of the sphere 6 evaluated by the Abrasionstest formed bullet abrasion mark. The corre diameter is the diameter of a circle with the same surface area as the entire surface of the ball abrasion mark.

(2) Chemical stability test

Each test oil 40 in an amount of 40 g, that of the base oil, ie polypropylene glycol monomethyl ether, 0.5% of 2,6-di-tert-butyl-4-methylphenol, 1% Phenylglycidylether and a phosphorus compound in each of Table 1, and adjusted to a water content of 2000 ppm, was poured into a glass bottle. The bottle was placed in a volume of 200 cm ³ together with a Fe / Cu / Al catalyst in a pressure vessel made of SUS, whereupon the container was filled with 8 g CO ₂ and sealed. After a residence time of 90 h at 175 ° C, the presence or absence of an insoluble substance deposit in the test oil 40 was determined.

The Results, d. H. the corresponding diameters of the ball abrasion mark and the chemical stability by evaluation of the Test oils (the refrigerating machine oil compositions), by mixing the phosphorus compounds with the base oil, Propylene glycol monomethyl ether according to the methods indicated above were obtained in the amounts indicated in Table 1 are in Table 1 given.

Comparative Example 1

The results obtained by evaluating the test oil consisting of the base oil, propylene glycol Monomethxlether, but without Phhosphorverbindung, in the manner indicated above, are given in Table 1. Table 1 No phosphorus compound Diameter of the abrasion mark (μm) stability kind Content (% by weight) Example 1 triphenyl 0.001 145 no deposition Ex. 2 triphenyl 0.01 106 ne deposition Example 3 triphenyl 0.1 79 no deposition Example 4 triphenyl 0.3 77 no deposition Example 5 triphenyl 1 71 no deposition Example 6 triphenyl 3 69 no deposition Example 7 triphenyl 10 68 low deposition Ex. 8 triphenyl 20 68 deposition Ex. 9 trioctyl 0.001 144 no deposition Ex. 10 trioctyl 0.01 104 no deposition Ex. 11 trioctyl 0.1 81 no deposition Ex. 12 trioctyl 0.3 74 no deposition Ex. 13 trioctyl 3 72 no deposition Ex. 14 trioctyl 10 71 low deposition Ex. 15 trioctyl 20 71 deposition Ex. 16 dibutyl 0.001 165 no deposition Ex. 17 dibutyl 0.01 117 no deposition Ex. 18 dibutyl 0.1 92 no deposition Ex. 19 dibutyl 0.3 87 no deposition Ex. 20 dibutyl 3 73 no deposition Example 21 dibutyl 10 71 low deposition Ex. 22 dibutyl 20 69 deposition Ex. 23 triethylphosphite 1 79 no deposition Ex. 24 tributyl 3 78 no deposition Example 25 tridecyl 1 76 no deposition Ex. 26 trilaurylphosphite 3 80 no deposition Ex. 27 diphenyl 1 81 no deposition Ex. 28 dilauryl 3 70 no deposition Ex. 29 Tri-n-butyl-methylphosphonium dimethylphosphate 0.001 150 no deposition Ex. 30 Tri-n-butyl-methylphosphonium dimethylphosphate 0.01 108 no deposition Ex. 31 Tri-n-butyl-methylphosphonium dimethylphosphate 0.1 84 no deposition Ex. 32 Tri-n-butyl-methylphosphonium dimethylphosphate 0.3 79 no deposition Ex. 33 Tri-n-butyl-methylphosphonium dimethylphosphate 1 82 no deposition Ex. 34 Tri-n-butyl-methylphosphonium dimethylphosphate 3 98 no deposition V. Example 1 no - 157 no deposition

table 1 shows that the refrigerating machine oil compositions according to the invention, the other phosphorus compounds as phosphate esters in amounts of 0.1 to 3 wt .-%, in the chemical stability test show no deposits of insoluble substance and in the HFRR test only small ball abrasion marks with a corresponding Diameter of less than 100 microns on the surface show the ball, and thus are very stable.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - JP 8-311472 [0003]
• - JP 2002-97486 [0003]

Claims (10)

Refrigerator oil composition for a chiller, in the carbon dioxide as Coolant is used, wherein the refrigerator oil composition a base oil composed of a synthetic oil contains, which is at least one kind of another phosphorus compound as a phosphate ester. Refrigerator oil composition according to claim 1, wherein the phosphorus compound comprises at least one compound, selected from the group consisting of a metal salt an inorganic phosphoric acid, an amine salt of a inorganic phosphoric acid, an ester of phosphorous Acid, a metal salt of an organic phosphorous Acid, an amine salt of an organic phosphorous acid and a phosphorus-containing ionic liquid. Refrigerating machine oil composition according to claim 2, wherein the phosphorus compound comprises at least one compound, selected from the group consisting of esters of phosphorous Acid, is. Refrigerator oil composition according to claim 3, wherein the phosphorous acid ester at least one ester selected from the group consisting from triphenyl phosphite, trioctyl phosphite, dibutyl phosphite, triethyl phosphite, Tributyl phosphite, tridecyl phosphite, trilauryl phosphite, diphenyl phosphite and dilauryl phosphite. Refrigerator oil composition according to claim 3, wherein the phosphorous acid ester at least one ester selected from the group consisting from triphenyl phosphite, trioctyl phosphite, and diphenyl phosphite. Refrigerator oil composition according to claim 1, wherein the phosphorus compound comprises at least one compound, selected from the group consisting of phosphorus-containing ionic liquids, is. Refrigerator oil composition according to claim 6, wherein the phosphorus-containing ionic liquid is tri-, n-butyl-methylphosphonium dimethyl phosphate. Refrigerator oil composition according to any one of claims 1 to 7, wherein the content of the Phosphorus compound 0.1 to 3 wt .-% is. Refrigerator oil composition according to any one of claims 1 to 8, wherein the synthetic oil at least one oil selected from the group consisting of polyoxyalkylene glycols and polyesters. The refrigerator oil composition according to any one of claims 1 to 9, wherein the kinematic viscosity of the base oil at a temperature of 100 ° C is 2 to 50 mm ² / s. is.