JP7093570B2 - Refrigerant composition - Google Patents

Description

The present invention relates to a composition for a refrigerant used as a refrigerating machine oil.

Generally, refrigerating machine oil is used as a lubricating oil for a refrigerant compressor in refrigerating and air-conditioning equipment such as air conditioners, refrigerators, car air conditioners, industrial refrigerators, and showcases. Since this refrigerating machine oil circulates in the refrigerating and air-conditioning equipment while mixing with the refrigerant, performance that matches the characteristics of the refrigerant is required. As such a refrigerating machine oil, for example, a refrigerating machine oil containing alkylbenzene as a base oil is known (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 10-24651

However, since the above-mentioned refrigerating machine oil has poor compatibility with the ultra-low temperature refrigerant, the oil does not return well in the refrigerating and air-conditioning equipment, and as the operating temperature of the refrigerating and air-conditioning equipment decreases, clogging occurs and the temperature does not decrease. Therefore, it has become a big problem as a refrigerating and air-conditioning device. As the refrigerant for ultra-low temperature, R-13 having a boiling point of -81.5 ° C, R-14 having a boiling point of -128.0 ° C, R-23 having a boiling point of -82.0 ° C, and R- having a boiling point of -78.3 ° C. 41, R-116 with a boiling point of -78.1 ° C, R-503 with a boiling point of -87.8 ° C, R-508A with a boiling point of -87.6 ° C, and R-508B with a boiling point of -87.6 ° C. As described above, the ultra-low temperature refrigerant has an extremely low boiling point and is excellent in cooling capacity.

Therefore, in view of the above problems, the present invention provides a composition for a refrigerant having high compatibility, low temperature characteristics, chemical stability as a refrigerating machine oil, lubricity, and electrical characteristics. The purpose is.

The above object of the present invention is achieved by the following means.

That is, the composition for a refrigerant according to claim 1 has a boiling point of -181.5 ° C., R-13, a boiling point of -128.0 ° C., R-14, a boiling point of -82.0 ° C., R-23, and a boiling point of −78. R-41 at 3 ° C, R-116 at boiling point-78.1 ° C, R-503 at boiling point-87.8 ° C, R-508A at boiling point-87.6 ° C, R-508B at boiling point-87.6 ° C. The following general formula (1) obtained by further reacting an intermediate obtained by reacting a monocarbonate with a dihydric alcohol as a refrigerating machine oil used for an ultra-low temperature refrigerant composed of any of the above with a monovalent alcohol. It is characterized by containing a polycarbonate compound represented by (1) as a base oil .

In the formula (1), R ¹ and R ³ are independently linear or branched hydrocarbon groups having 1 to 30 carbon atoms, or hydrocarbon groups containing an aromatic ring or an alicyclic bond. .. R ² is a linear or branched divalent hydrocarbon group having 1 to 12 carbon atoms, or a divalent hydrocarbon group containing an aromatic ring or an alicyclic bond, and a is an integer of 1 to 16. ..

Further, the invention of claim 2 is characterized in that, as the refrigerating machine oil, at least one kind of composition different from the above-mentioned claim 1 is contained.

Further, the invention of claim 3 is at least one selected from extreme pressure agents, oily agents, antioxidants, acid scavengers and defoamers in the composition for refrigerant according to claim 1 or 2. It is characterized by containing the additive of.

According to the present invention, it is possible to provide a composition for a refrigerant having high compatibility, low temperature characteristics, chemical stability as a refrigerating machine oil, lubricity, and electrical characteristics.

The composition for a refrigerant according to the present invention contains one or more of the carbonate compounds represented by the above general formula (1) as refrigerating machine oil.

In the formula (1), R ¹ and R ³ are independently linear or branched hydrocarbon groups having 1 to 30 carbon atoms, or hydrocarbon groups containing an aromatic ring or an alicyclic bond. .. R ² is a linear or branched divalent hydrocarbon group having 1 to 12 carbon atoms, or a divalent hydrocarbon group containing an aromatic ring or an alicyclic bond, and a is an integer of 1 to 16. ..

Examples of such a carbonate compound include dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate, diisopropyl carbonate, dibutyl carbonate, dicyclohexyl carbonate and the like.

By the way, the composition for a refrigerant according to the present invention contains at least one kind of composition different from the above-mentioned carbonate compound. That is, the composition for a refrigerant according to the present invention uses an intermediate obtained by reacting a carbonate compound and a dihydric alcohol as described above, and a polycarbonate compound obtained by further reacting with a monohydric alcohol as a base oil. It is used as a refrigerating machine oil contained. Thereby, it is possible to provide a composition for a refrigerant having high compatibility, low temperature characteristics, chemical stability as a refrigerating machine oil, lubricity, and electrical characteristics.

Examples of this dihydric alcohol include 3-methyl-1,5-pentanediol, 1,3-propanezyl, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,7-. Heptangyl, 1,8-octanediol, 2-ethyl-1,6-hexanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 1,3-cyclohexanediol, 2,2'-bis- (4-Hydroxycyclohexyl) -propane, p-xylenediol, p-tetrachloroxylenediol, 1,4-dimethylolcyclohexane, (3 (4), 8 (9) -bis- (hydroxymethyl) -tricyclode Examples thereof include candimethylol, bis-hydroxymethyltetrachloride, di (2-hydroxyethyl) dimethyl hydantin, diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, polytetramethylene glycol and the like.

The monovalent alcohols include 3-methyl-1-butanol, 2-ethyl-1hexanol, 3-methyl-1-hexanol, 5-methyl-1-hexanol, methanol, ethanol, 1-propanol and 2-propanol. , 1-butanol, 2-butanol, 2-methyl-1-propanol, 2-methyl-2-propanol, 1-pentanol, 2-pentanol, 3-pentanol, 3-methyl-1-butanol, 1- Hexanol, 2-hexanol, 3-hexanol, 2-methyl-1-pentanol, 2-ethyl-butanol, 1-heptanol, 2-heptanol, 3-heptanol, 2-methyl-1-hexanol, 2-ethyl-1 -Pentanol, 1-octanol, 2-octanol, 3-octanol, 2-methyl-1-heptanol, 1-nonanol, 2-nonanol, 3-nonanol, 2-methyl-1-octanol, 2-ethyl-1- Examples thereof include heptanol, 1-decanol, 2-decanol, 3-decanol, 2-methyl-1-nonanol, 2-ethyl-1-octanol and the like.

As a synthetic method for further reacting the intermediate obtained by reacting the carbonate compound with the dihydric alcohol as described above with the monohydric alcohol, a conventionally known method can be used, for example, a special case. It is a method as described in Kaisho 62-187725.

On the other hand, it is also possible to include at least one additive selected from extreme pressure agents, oily agents, antioxidants, acid scavengers and defoaming agents in the above-mentioned refrigerant composition. Even if such an additive is included, the composition for a refrigerant according to the present invention has high compatibility, low temperature characteristics, chemical stability as a refrigerating machine oil, lubricity, and electricity. It has characteristics.

Hereinafter, the present invention will be specifically described with reference to Examples.

<Composition for Refrigerant (Examples 1 to 12)>
In Example 1, a refrigerating machine oil obtained by reacting an intermediate obtained by reacting dimethyl carbonate with 3-methyl-1,5-pentanezyl and further reacting with 3-methyl-1-butanol. As a carbonate oil was synthesized.

In Example 2, a refrigerating machine oil obtained by reacting an intermediate obtained by reacting dimethyl carbonate with 3-methyl-1,5-pentanezyl and further reacting with 2-ethyl-1-hexanol. As a carbonate oil was synthesized.

In Example 3, an intermediate obtained by reacting dimethyl carbonate with 3-methyl-1,5-pentanezyl was further added with 3-methyl-1-butanol and 2-ethyl-1-hexanol. Carbonate oil was synthesized as the refrigerating machine oil obtained by reacting with the mixture.

As Example 4, a carbonated oil was prepared by mixing the carbonated oils of Example 1, Example 2 and Example 3 at a ratio of 1: 1: 1.

In Example 5, an intermediate obtained by reacting dimethyl carbonate with 3-methyl-1,5-pentanezyl was further added with 3-methyl-1-hexanol and 5-methyl-1-hexanol. Carbonate oil was synthesized as the refrigerating machine oil obtained by reacting with the mixture.

In Example 6, an antioxidant (2,6-di-tert-butyl-p-cresol (BHT)) was added to the carbonate oil of Example 4, and an extreme pressure agent (tricresol) was added. 0.5 wt% phosphate (TCP), 0.5 wt% extreme pressure agent (triphenylphosphate (TPP)), and acid supplement (3', 4'-epoxycyclohexylmethyl 3,4 epoxycyclohexane). It was prepared by adding 0.5 wt% of carboxylate) and 0.002 wt% of antifoaming agent (dimethylsiloxane).

As Example 7, a mixture of the carbonate oil of Example 5 and the polyol ester oil was prepared so that the carbonate oil / polyol ester oil = 80 vol% / 20 vol%.

As Example 8, 0.1 wt% of an antioxidant (2,6-di-tert-butyl-p-cresol (BHT)) was added to the carbonate oil of Example 4.

As Example 9, 0.5 wt% of an extreme pressure agent (tricredil phosphate (TCP)) was added to the carbonate oil of Example 4 to prepare the oil.

As Example 10, 0.5 wt% of an extreme pressure agent (triphenyl phosphate (TPP)) was added to the carbonate oil of Example 4.

As Example 11, 0.5 wt% of an acid supplement (3', 4'-epoxycyclohexylmethyl 3,4 epoxycyclohexanecarboxylate) was added to the carbonate oil of Example 4.

As Example 12, a defoaming agent (dimethylsiloxane) added in an amount of 0.002 wt% to the carbonate oil of Example 4 was prepared.

<Composition for Refrigerant (Comparative Examples 1 to 4)>
Comparative Example 1 uses a polyol ester oil as the refrigerating machine oil, Comparative Example 2 uses polyvinyl ether oil as the refrigerating machine oil, and Comparative Example 3 uses a naphthenic mineral oil as the refrigerating machine oil. As Comparative Example 4, alkylbenzene oil was used as the refrigerating machine oil.

<Test items>
The tests shown in Table 1 below were carried out for Examples 1 to 12 and Comparative Examples 1 to 4.

<Test item (compatibility)>
Among the above test items, the compatibility was tested by using the refrigerant R-23 as the test conditions, setting the refrigerating machine oil / refrigerant mixing ratio to 55/45 (wt%), and setting the temperature to −40 ° C.

<Test items (low temperature characteristics)>
Among the above test items, the low temperature characteristics are as follows: (1) Refrigerating machine oil prepared with a predetermined amount of water and the refrigerant are weighed in a test tube (shield tube) and sealed, and (2) the test tube is kept at the specified temperature. After cooling to, and allowing to stand for 24 hours, (3) after standing, the separated state and fluidity of the solution were observed, and the compatibility between the refrigerating machine oil and the refrigerant was evaluated. The evaluation method was 〇: good, ×: bad.

As the test conditions, the refrigerant R-23 was used, the refrigerating machine oil / refrigerant mixing ratio was 50/50 (wt%), the water content was 50 mg / kg (ppm) or less, and the temperature was −80 ° C..

<Test items (Farex load-bearing test)>
Among the above test items, in the Farex load-bearing test, after performing a Narashi operation at 1112N for 5 minutes, the load was applied by an automatic weighting device manufactured by FALEX, and the load generated by seizure was defined as the seizure load.

<Test items (chemical stability)>
Among the above test items, for chemical stability, (1) a refrigerating machine oil prepared to have a predetermined amount of water, a refrigerant, and a metal catalyst are sealed in a test tube and heated at 175 ° C. for 14 days. 2) After heating, the stability of the refrigerating machine oil and the influence of the metal were confirmed, and the chemical stability of the refrigerating machine oil and the refrigerant was evaluated. The evaluation method was 〇: good, ×: bad.

As the test conditions, the refrigerant R-23 is used, Fe, Cu, and Al having a diameter of 1.6 mm and a length of 50 mm are used as the metal catalyst, and the refrigerating machine oil / refrigerant mixing ratio is 1.0 g / 0.1 g. , The test was carried out with a water content of 50 mg / kg (ppm) or less.

<Test results>
Table 2 shows the test results of the above test method.

As is clear from the results shown in Table 2 above, the composition for a refrigerant according to the present invention has high compatibility, low temperature characteristics, chemical stability as a refrigerating machine oil, and lubricity. In addition, it was found to have electrical characteristics.

Further, according to the composition for a refrigerant according to the present invention, even if an additive is added, it has high compatibility and low temperature characteristics, and further, has chemical stability as a refrigerating machine oil, lubricity, and lubricity. It turned out to have electrical characteristics.

Claims (3)

Boiling point -81.5 ° C. R-13, Boiling point -128.0 ° C. R-14, Boiling point -82.0 ° C. R-23, Boiling point -78.3 ° C. R-41, Boiling point -78.1 ° C. R-116, boiling point -87.8 ° C. R-503, boiling point -87.6 ° C. R-508A, boiling point -87.6 ° C. R-508B. As a machine oil , an intermediate obtained by reacting a monocarbonate with a dihydric alcohol is further contained as a base oil, and a polycarbonate compound represented by the following general formula (1) obtained by reacting with the monovalent alcohol is contained as a base oil. A composition for a refrigerant characterized by becoming .

[In the formula (1), R ¹ and R ³ are independently linear or branched hydrocarbon groups having 1 to 30 carbon atoms, or hydrocarbon groups containing an aromatic ring or an alicyclic bond. be. R ² is a linear or branched divalent hydrocarbon group having 1 to 12 carbon atoms, or a divalent hydrocarbon group containing an aromatic ring or an alicyclic bond, and a is an integer of 1 to 16. .. ] A composition for a refrigerant, which comprises at least one composition different from that of claim 1 as a refrigerating machine oil. The composition for a refrigerant according to claim 1 or 2, which comprises at least one additive selected from an extreme pressure agent, an oily agent, an antioxidant, an acid scavenger and an antifoaming agent.