JPH02132179A - 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 the formula [R is hydrocarbon; R<1> is alkylene; R<2> is fluorine- containing 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 ratio 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] Conventionally, naphthenic mineral oil, paraffinic mineral oil, alkylbenzene-based synthetic oil, and poly-α-olefin-based synthetic oil are known as lubricating oils for fluorocarbon compressors. It is used to prevent friction, wear, and seizure.

Characteristics required for lubricating oil for fluorocarbon compressors: Unlike general lubricating oils, since it involves contact with fluorocarbons as a refrigerant, it must have good stability against refrigerants and low solubility with refrigerants. It is required to be of excellent quality and not to dissolve the polymeric materials used as materials, such as packing.

Conventionally, dichloromethane (hereinafter referred to as Rl2) used as a refrigerant is replaced with conventionally used naphthenic mineral oils, paraffinic mineral oils, alkylbenzene synthetic oils, and polyolefin synthetic oils. Although oil satisfies the above-mentioned requirements, it has been pointed out that completely halogenated fluorocarbons pose an environmental problem due to ozone layer depletion, and there is an urgent need to develop a new refrigerant to replace R12. , as a new refrigerant to replace R12,
l, 1. 2-tetrafluorethane (hereinafter Rl34
(referred to as "a") is regarded as a striking force, but when used as a refrigerant, lubricating oil is indispensable.

[Problems to be Solved by the Invention] R134a compressor lubrication nl+ As for the conventionally known naphthene-based mineral oil, baraffin-based mineral oil, alkylbenzene-based synthetic oil, and Boli 101-year-old lefin-based synthetic oil, Regarding one of the requirements, the solubility of R134a in the lubricating oil, it has the disadvantage of not exhibiting 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, decreases the amount of oil in the compressor, and also 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 (0■] groups) has been proposed as a lubricating oil that exhibits solubility with R134a (USP 4,755,
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.

CG11F+(:H30H-ICIICI■P + l
A similar reaction occurs in the combination of IclIO+ IIcIRl34a and polyalkylene glycol oil having an alcoholic hydroxyl group. If such decomposition occurs, the hydrogen halide produced as a result of the decomposition may cause corrosion of equipment, deterioration of lubrication performance, etc., which is undesirable.

[Means for Solving the Problems] The present invention should solve the above-mentioned problems. As a result of repeated inspections of R134a compressor lubricating oil, the present company has found that it is preferable to improve the alcoholic hydroxyl group (0[I group) in alkylene glycol oil as in the following compound (1). This discovery led to the completion of the present invention.

R-(1 {R'-0}., R"... (I) [R is a hydrocarbon group, Rl is an alkylene group, R2 is a fluorine-containing alkyl group, n is -L, the viscosity of the compound (I) is 1.0 ~30
0 c. st (a positive number at 40°C)] That is, the present invention aims to prevent friction, wear, seizure, etc. in the sliding parts of the compressor by using the compound (1) as a lubricating oil for the Rl34a compressor. Compression refrigeration, consisting of compound (1) and Rl34a, is concerned with river compositions.

The compound (N) in the present invention has a viscosity of lO to 300cst in order to sufficiently achieve functions such as friction, wear and seizure prevention in the sliding parts of the compressor.
．． It is preferable that the molecular weight or the value of n in compound (I) is selected such that the viscosity falls within such a viscosity range.

R ii in the compound (1) - saturated or unsaturated linear or branched hydrocarbon group, preferably having 1 carbon number
~lO alkyl group. As R'O, ethylene oxide, brobylene oxide, butylene oxide, etc. are preferable, and brobylene oxide is particularly preferable.

Further, a block or random combination of two or more of these alkylene oxides may be used, and in this case, propylene oxide is preferably used as the main component. R8 is a linear or branched fluorine-containing alkyl group having 1 to 20 carbon atoms, a barfluoroalkyl group in which all the hydrogen atoms of the alkyl group are substituted with fluorine atoms, or a barfluoroalkyl group in which all or some of the hydrogen atoms are fluorine atoms. is a polyfluoroargyl group substituted with a halogen atom such as a chlorine atom.

The weight m ratio of the compound (I) and R134a is 1799-9
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 A small amount of stabilizers such as phosphite compounds such as , diisobutyl phosphite and diphenyl phosphite, phosphine sulfide compounds such as triphenoxyphosphine sulfide and 1-limethylphosphine sulfide, and other glycidyl ethers may be added. In addition, naphthenic mineral oils, paraffinic mineral oils, alkylbenzene synthetic oils, polyα-olefin synthetic oils, fluorinated polyether oils which are fluorinated lubricating oils, which are conventionally used with the compound (I) of the present invention, It can be used in combination with fluorine-containing silicone oil or the like, or 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, R1
Solubility and stability tests were conducted with 34a. Compound (I) and Rl34a were sealed in a glass ampoule at a weight ratio of 30/70, and the presence or absence of dissolution of compound (I) and Rl34a was determined by visual observation based on the presence or absence of an interface between the two liquids. 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 8 Naphthenic oil manufactured by Nippon Sun Oil Co., Ltd.
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 combination of conventionally used Rl2 and Suniso 4GS (naphthenic oil manufactured by Nippon Sun Oil Co., Ltd.) (cst, at 40°C) [Effects of the invention] This book As is clear from the examples, the composition for compression refrigerators of the invention has good solubility and stability, and is an excellent product that can prevent friction, wear, and seizure in the sliding parts of the compressor. be.

Claims (1)

[Claims] 1. General formula▲ Numerical formulas, chemical formulas, tables, etc.▼...(I) [R is a hydrocarbon group, R^1 is an alkylene group, R^2 is a fluorine-containing alkyl group, n is The viscosity of the above compound (I) is 1
A composition for a compression refrigerator comprising a compound represented by a positive number ranging from 0 to 300 cst (40°C) and 1,1,1,2-tetrafluoroethane.