JPS6115118B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a new rotary refrigerating machine oil, and more specifically to a new lubricating oil composition for use in a rotary compressor of a refrigerating machine. Conventionally, as a lubricating oil for a rotary compressor of a refrigerator, a naphthenic lubricating base oil or a naphthenic liquid paraffin to which various lubricating oil additives such as an extreme pressure agent and an antioxidant have been added has been used. For example, JP-A No. 47-42440 discloses a refrigeration oil consisting of a hydrorefined naphthenic oil component and a dewaxed paraffin component, and this refrigeration oil has good chemical stability and thermal stability. have. However, as compressors have recently become smaller and lighter, the operating temperature has become higher than conventional compressors due to reasons such as low heat dissipation, resulting in problems such as carbon sludge sticking to the discharge port and increased wear on sliding parts. There's a problem. As a result of various studies to solve such problems, the inventors of the present invention have unexpectedly found that highly refined paraffinic mineral oil can be used as a lubricating oil for rotary machines and has an extremely excellent effect as a refrigerating machine oil. I discovered that. That is, according to the present invention, a lubricating oil composition is obtained by adding certain additives to a highly refined paraffinic mineral oil that has an iodination of 1.0 or less and does not contain aromatic components (measured by the NDM method). When the lubricating oil composition is used as a rotary refrigerating machine oil, the heat resistance temperature of the lubricating oil composition is about 100% higher than that of conventional naphthene-based lubricating oil compositions.
The temperature is also increased by 10°C, and the abrasion resistance is also improved. Therefore, the adhesion of carbon sludge in the discharge port and the wear of each sliding part can be significantly suppressed. The highly refined mineral oil used in the lubricating oil composition of the present invention is obtained by, for example, two-stage hydrogenation treatment of a crude lubricating oil fraction obtained by distilling a crude oil such as Arabian Light crude oil or Kuwaiti crude oil at normal pressure and then distilling it under reduced pressure. can get. That is, in the first stage hydrogenation process, the crude lubricating oil fraction is heated at a temperature of 310 to 480°C, a pressure of 105 to 700 Kg/cm ² , and a liquid hourly space velocity (hereinafter abbreviated as LHSV) of 0.1 to 10/hr.
catalytic hydrogenation. The hydrogenation catalyst used at this time consists of one or more metals of Group 1 or Group 3 of the periodic table, or oxides or sulfides of these metals. In particular, it is preferable to use Ni-W sulfide. In the second stage hydrotreating process, the mineral oil hydrotreated in the first stage process is heated to
205~400℃, pressure 70~700Kg/ ^cm2 , LHSV0.1~
Catalytic hydrogenation is carried out at a rate of 10/hr using a catalyst consisting of one or more metals of group 1 or group 3 of the periodic table or oxides or sulfides of these metals. Regarding such two-stage catalytic hydrogenation treatment, for example, Japanese Patent Publications Nos. 33-7383 and 47-
No. 13418, No. 51-15046 or Japanese Patent Application Laid-open No. 1973-
This is disclosed in Publication No. 66606, etc. The lubricating base oil highly refined in this way must have an iodine value of 1.0 or less. Mineral oil that has been highly refined in this way contains extremely few impurities with polar groups, such as nitrogen-containing compounds and sulfur compounds.
It does not contain aromatic components (measured by the NDM method), and not only has a remarkable effect of adding additives, but also has high stability against refrigerants such as Freon. Used in the refrigeration oil of the present invention The analytical values of the highly refined paraffinic lubricating base oil preferred for this purpose are shown in the following table, for example.

【table】

[Table] Phenyl-α-naphthylamine and/or tricresyl phosphate are used as additives to be added to the highly purified paraffinic lubricating base oil of the present invention. The additives according to the invention, phenyl-α-naphthylamine and tricresyl phosphate, alone or in combination, are 0.01 to 10.0% by weight based on the base oil.
Can be added. The refrigerating machine oil of the present invention can also be used by adding a synthetic lubricant, such as an alkylbenzene, to a highly refined paraffinic base oil. The refrigerating machine oil of the present invention will be explained in more detail with reference to the following examples. Example Arabian Light crude oil was distilled at normal pressure and then distilled under reduced pressure to obtain a crude lubricating oil fraction, which was further subjected to two-stage hydrogenation treatment to produce a paraffinic lubricating base oil with an iodine value of 0.2. This base oil contains 0.05% by weight of phenyl-α-naphthylamine and tricresyl phosphate.
Refrigerating machine oil of the present invention was prepared by adding 1.1% by weight. The following test was conducted to compare this refrigerating machine oil with a naphthenic lubricating base oil containing the same additives in the same amount. (1) Falex pin wear test (based on ASTMD 2670-67) Test conditions are as follows. Load: 450lbs Refrigerant (R-22) injection amount: 180ml/min Oil temperature: 130℃±10℃ Test time: 4.5 hours The average wear amount of Faloxpin compared to the refrigeration oil of the present invention and a comparison product using naphthenic lubricating base oil is 20.5, respectively. ±5.8mg and 30.5±7.5mg, which shows that the refrigerating machine oil of the present invention has excellent wear resistance performance. Also, oil amount (T.℃) and seizure load (W.lbs)
Figure 1 shows the results of measuring the changes in the As is clear from FIG. 1, at the operating temperature of the compressor (oil temperature of around 120° C.), the seizure load of the refrigerating machine oil of the present invention is approximately 100 lbs or more greater than that of the comparative product. (2) Bench test The test conditions are as follows. Using 20 compressor RC1.5HP Ambient temperature: 45 to 48℃ Compressor case temperature: 114 to 129℃ Operating time: 210 days The above test was conducted on the refrigeration oil of the present invention and a comparative product, and the wear status of the compressor rollers and vanes was observed. The results of the evaluation are shown in Figure 2. In the figure, the horizontal axis is the number of compressors (%). The evaluation rankings are shown in Table 2.

【table】

[Table] As is clear from Fig. 2, when the refrigerating machine oil of the present invention (Fig. 2-1) was used, the wear of the rollers and vanes was rated A to C, and the comparison product (Fig. 2-1) was rated A to C.
It can be seen that the refrigerating machine oil of the present invention has an extremely excellent effect in suppressing the wear of the compressor sliding parts, compared to the evaluations C to E obtained when using Fig. 2).

[Brief explanation of the drawing]

Figure 1 shows Falex between the refrigeration oil of the present invention and a comparative product.
FIG. 2 is a diagram showing the results of the test, and FIG. 2 is a diagram showing the results of a bench test of the refrigerating machine oil of the present invention and a comparative product.

Claims (1)

[Claims] 1 Paraffinic highly refined lubricating oil base oil with an iodine value of 1.0 or less and containing no aromatic components (measured by the NDM method) obtained through hydrogenation treatment,
Phenyl-α-naphthylamine or/and tricresyl phosphate from 0.01 to base oil
Rotary refrigeration oil containing 10.0% by weight.