JPH0393895A - Composition for compression type refrigerator - Google Patents

Abstract

PURPOSE:To obtain the title composition consisting of a fluorine-containing olefin based synthetic oil having a specific viscosity and tetrafluoroethane, having good solubility and stability and capable of preventing friction, abrasion and seizure in sliding part of compressor. CONSTITUTION:The aimed composition obtained by blending (A) a fluorine- containing olefin based synthetic oil having 10-300cst viscosity (at 40 deg.C) and preferably expressed by the formula [R is F, Cl or CF3 (especially Cl)] with (B) tetrafluoroethane at a weight ratio of 1/99-99/1 (preferably 5/95-60/40).

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a composition for compression refrigerators that prevents friction, wear, seizure, etc. in the sliding parts of the compressor used in compression refrigerators. .

[Prior Art] Conventionally, naphthenic mineral oils, paraffinic mineral oils, alkylbenzene-based synthetic oils, and polyα-olefin-based synthetic oils have been known as lubricating oils for fluorocarbon compressors. , used for the purpose of preventing wear and seizure, etc.

The characteristics required for a lubricating oil for a fluorocarbon compressor are that, unlike general lubricating oils, it comes into contact with fluorocarbons as a refrigerant, so it must have good stability against the refrigerant, and it must have excellent solubility with the refrigerant. It is required that the polymer material used as the material, such as packing, not be dissolved.

In contrast to dichlorodifluoromethane (hereinafter referred to as R12), which is conventionally used as a refrigerant, naphthenic mineral oil, which is conventionally used, is used as a refrigerant. Paraffinic mineral oil, alkylbenzene synthetic oil, and polyα-olefin synthetic oil satisfy the above requirements, but environmental problems have been pointed out due to the ozone layer depletion of fully halogenated fluorocarbons. Therefore, there is an urgent need to develop a new refrigerant to replace R12. Tetrafluoroethane, especially 1,1,1,2-tetrafluoroethane (hereinafter referred to as R134a), is considered to be a promising new refrigerant to replace R12, but lubricating oil is indispensable when used as a refrigerant. .

[Problems to be Solved by the Invention] Conventionally known naphthenic mineral oils, paraffinic mineral oils, alkylbenzene synthetic oils, and boly α-olefin synthetic oils do not meet the requirements for lubricating oils for R134a compressors. In terms of the solubility of R134a in lubricating oil, R134a has the disadvantage of not showing any solubility.

If the solubility of Rl34a and lubricating oil is poor, the lubricating oil carried out by droplets from the compressor will separate from the refrigerant in the condenser, evaporator, dryer, piping, etc., resulting in extremely high viscosity. This is undesirable because it causes failure in the return of oil to the compressor, resulting in a decrease in the amount of oil in the compressor, and further causes problems such as friction and abrasion in sliding parts and seizing of the compressor.

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems. The present invention relates to a composition for a type refrigerator.

The fluorine-containing olefin-based synthetic music in the present invention includes:
Those represented by the following general formula (1) are preferred.

R 1 {CF-CF2''}n・' (1) (R is F, Cl, or CF3) The compound (1) has sufficient functions such as preventing friction, wear, and seizure in the sliding parts of the compressor. In order to achieve this, the viscosity is preferably 5 to 300 cst (40° C.), and the molecular weight or value of n in compound (1) is preferably selected such that the viscosity falls within this range. R in the compound (1) is F,
It is selected from Cl or CF3, and 01 is preferable in terms of compatibility with the refrigerant.

The weight ratio of the compound (1) and tetrafluoroethane is l/99 to 99/1, preferably 5/95 to 60/40.
It is.

The composition of the present invention is particularly effective in the application of refrigeration cycles for freezing, refrigeration, and air conditioning in low-temperature to high-activity fields, but it can also be used for various other heat recovery technologies such as Rankine cycle. It is.

The composition of the present invention has excellent thermal stability and does not require a stabilizer under normal usage conditions, but when it is necessary to improve thermal stability due to harsh usage conditions, dimethyl phosphite ．． A small amount of stabilizers such as phosphite compounds such as diisobutyl phosphite and diphenyl phosphite, phosphine sulfide compounds such as triphenoxyphosphine sulfide and trimethylphosphine sulfide, and glycidyl ethers may be added.

Furthermore, the compound (1) of the present invention and a conventionally used naphthenic mineral oil. Can be mixed with paraffinic mineral oil, alkylbenzene synthetic oil, polyα-olefin synthetic oil, fluorine-containing olefin synthetic oil, which is a fluorinated lubricating oil, fluorine-containing silicone oil, etc., or polyalkylene glycol oil having a hydroxyl group, etc. is possible.

Additionally, various additives such as phenol-based or amine-based antioxidants, sulfur- or phosphorus-based extreme pressure additives, silicone-based antifoaming agents, or metal deactivators such as penzotriazole may be added to the composition of the present invention. It may be further added to.

[Example] Using the compounds shown in Tables 1 and 2 below, Rl34a
Solubility and reactivity tests were conducted with

Compound (1) and R134a were sealed in a glass ampoule at a weight ratio of 30/70.
The presence or absence of dissolution and the presence or absence of a two-liquid interface were visually observed. The results are shown in Table 1 along with comparative examples.

Compound (1) in Table 1 and R134a in a weight ratio of 50/50
Typical metal SS 41 and Cu to US316 pressure container
The sample was sealed together with the sample and left in a constant temperature bath at a high temperature of 175°C for 14 days, and the state of deterioration after the test was confirmed. The results are shown in Table 2.

Table 2 [Effects of the Invention] As is clear from the examples, the composition for compression refrigerators of the present invention has good solubility and stability, and prevents friction, wear, and seizure in the sliding parts of the compressor. This is an excellent product that allows you to achieve the following.

Claims (1)

[Claims] (1) A composition for a compression refrigerator comprising a fluorine-containing olefin synthetic oil having a viscosity of 10 to 300 cst (40°C) and tetrafluoroethane.