JPH02132176A - Composition for compression type refrigerator - Google Patents

Abstract

PURPOSE:To obtain the subject composition, consisting of a specific compound and tetrafluoroethane, excellent in solubility and stability and capable of preventing friction, abrasion and seizure in sliding parts of compressors. CONSTITUTION:The objective composition consisting of (A) a compound expressed by formula [X is halogen; R<1> is hydrocarbon; R<2> and R<3> are H or lower alkyl; n is a positive number so as to provide the compound expressed by the formula with 10-300cst viscosity (40 deg.C)] and (B) 1,1,1,2-tetrafluoroethane. Furthermore, the weight of the components (A) to (B) is 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] Naphthenic mineral oils, paraffinic mineral oils, alkylbenzene synthetic oils, and polyα-olefin synthetic oils are known as lubricating oils for compressors. It is used to prevent friction, wear, and seizure.

The characteristics required for lubricating oil for fluorocarbon compressors are as follows:
Unlike general lubricating oil, it involves contact with fluorocarbons as a refrigerant, so it must have good stability against refrigerants, excellent solubility with refrigerants, and high polymer materials such as packing used as materials. It is required that it does not dissolve.

In contrast to dichloromethane (hereinafter referred to as Rl2), which is conventionally used as a refrigerant, conventionally used naphthenic mineral oils, paraffinic mineral oils, alkylbenzene synthetic oils, and polyalpha-olefinic oils are used as refrigerants. Although synthetic oil satisfies the above-mentioned requirements, it has been pointed out that there are environmental problems due to ozone M destruction caused by completely halogenated fluorocarbons, and there is an urgent need to develop a new refrigerant to replace R12. There is. 1,1, as a new refrigerant to replace Rl2.
1.2-Tetrafluroethane (hereinafter referred to as R134a) is considered to be a promising option, but lubricating oil is essential when using it as a refrigerant. [Problems to be Solved by the Invention] Conventionally known naphthenic mineral oils, paraffinic mineral oils, alkylbenzene synthetic oils, and polyα-olefin synthetic oils meet the requirements for lubricating oils for R134a compressors. In terms of the solubility of Rl34a in lubricating oil, Rl34a has the disadvantage of not showing any solubility.

If the solubility of R134a 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 oil return to the compressor, decreases the amount of oil in the compressor, and causes problems such as friction and wear on sliding parts and seizure of the compressor.

On the other hand, polyalkylene glycol oil containing alcoholic hydroxyl groups (OH groups) has been proposed as a lubricating oil that is soluble in R134a (USP 4,755,3
16th grade). However, it is known that substances having alcoholic hydroxyl groups (OH groups) easily react with lower aliphatic halogenated hydrocarbons and decompose. As an example, the reaction between trichlorofluoromethane and methanol is shown below, but it is said that the reaction decomposes and produces aldehydes and ketones.

(,Cl.F+CIl.OH-40IC12F +I4
A similar reaction occurs in the combination of CIIO+l+CIR134a and polyalkylene glycol oil having an alcoholic hydroxyl group. When such decomposition occurs,
Corrosion of equipment due to hydrogen halides produced as a result of decomposition;
This is not preferable because it causes a decrease in lubrication performance.

[Means for Solving the Problems] The present invention solves the above-mentioned problems. As a result of repeated studies on R134a compressor lubricating oil, the present inventors found that alcoholic hydroxyl groups (OH groups) in alkylene glycol oil } was found to be preferable to be improved as shown in Compound (I) below, and the present invention was completed.

[X is a halogen atom, R′ is a hydrocarbon group, R2. R3 is H or a lower alkyl group, n is a positive number such that the viscosity of the above compound (I) is 10 to 300 cst (40°C)] and a compression formula consisting of 1,1,1,2-tetrafluoroethane Composition for refrigerators.

That is, the present invention provides a compressor comprising compound (J) and R134a, which can prevent friction, wear, seizure, etc. in the sliding parts of compressor by using the compound (I) as a lubricating oil for R134a compressor. The present invention relates to a composition for a type refrigerator.

In the present invention, the compound (1) has a viscosity of IO to 300c in order to sufficiently achieve functions such as preventing friction, wear and seizure in the sliding parts of the compressor.
st (40°C), and the compound (I
It is preferable to select the molecular weight or the value of n in ) such that the viscosity falls within this range.

X in the compound (I) is a halogen atom, with chlorine and fluorine being particularly preferred. 1 is a saturated or unsaturated straight or branched hydrocarbon group, preferably an alkyl group having 1 to 10 carbon atoms. R", R3 is I] or a lower alkyl group, R"=R3=1{ethylene oxide, R2=H and R3=(:lh brobylene oxide, R2=It': CI+3 or R2= }
{and Ill3=C. H5 butylene oxide and the like are preferred, with brobylene oxide → noide being particularly preferred. or,
A block or random combination of two or more of these alkylene oxides may be used, and in this case, it is preferable that brobylene oxide is the main component.

The ratio of compound (I) to Rl34a is l/99 to 9.
9/l, preferably 5/95 to 60/40.

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

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 is used. A small amount of stabilizers such as phosphite compounds such as , diisobulphosphite and diphenyl phosphite, phosphine sulfide compounds such as triphenoxyphosphine sulfide and trimethylphosphine sulfide, and glycidyl ethers may be added.

In addition, the compound (1) of the present invention and conventionally used naphthenic mineral oils, paraffinic mineral oils, alkylbenzene synthetic oils, polyα-olefin synthetic oils, and fluorinated polyether oils which are fluorinated lubricating oils. , fluorine-containing silicone oil, and polyalkylene glycol oil having a hydroxyl group.

Additionally, various additives such as phenol-based or amine-based antioxidants, sulfur-based 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 compound (I) shown in Tables 1 and 2 below, R
Solubility and stability studies with 134a were performed. Compound (1) and R1.34a were sealed in a glass ampoule at a weight ratio of 30/70, and the presence or absence of dissolution of compound (1) and R1.34a was determined by visual observation based on the presence or absence of a two-liquid interface. The results are shown in Table 1 along with comparative examples.

The first confirmation was made. The results are shown in Table 2 Table 2: Naphthenic oil manufactured by Nippon Sun Oil Co., Ltd. (cst., at 40°C)
Typical metals SS41 and Cu to S316 pressure-resistant containers
Compound (1). Rl34a,
The state of metal deterioration was confirmed by a relative comparison of the degree of deterioration between the conventionally used Rl2 and Suniso 4GS combinations.
Naphthenic oil manufactured by Nippon Sun Sekiura Co., Ltd. (cst, at 40°C) [Effects of the invention] As is clear from the examples, the composition for compression refrigerators of the present invention has good solubility and stability, This is an excellent product that can prevent friction, wear, and seizure in the sliding parts of the compressor.

Claims (1)

[Claims] 1. General formula ▲ Numerical formulas, chemical formulas, tables, etc. ▼... (I) [X is a halogen atom, R^1 is a hydrocarbon group, R^2, R
^3 is H or lower alkyl group, n is the above compound (I
) has a viscosity of 10 to 300 cst (40°C)]
A composition for a compression refrigerator comprising a compound represented by the formula and 1,1,1,2-tetrafluoroethane.