JPH02132178A - Composition for compression type refrigerator - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

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 oil, paraffin mineral oil, alkylbenzene synthetic oil, and polyα-olefin synthetic oil are conventionally known as lubricating oils for fluorocarbon compressors.
l It is used for the purpose of preventing friction, wear, and seizure in sliding parts.

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.

Conventionally, dichloromethane (hereinafter referred to as Rl2) is used as a refrigerant, while conventionally used naphthenic mineral oils, paraffinic mineral oils, alkylbenzene synthetic oils, and poly-α-olefin synthetic oils are used as refrigerants. Although oil satisfies the above-mentioned requirements, it has been pointed out that completely halogenated fluorocarbons cause environmental problems due to ozone layer depletion, and there is an urgent need to develop a new refrigerant to replace R12. 1{A new refrigerant to replace 12 is 1, l.
, I,2-tetrafluoroethane (hereinafter referred to as RI34a) is used as a refrigerant, but lubricating oil is essential when it is used as a refrigerant.

[Problems to be Solved by the Invention] Regarding R134a compressor lubricating oil, conventionally known naphthenic mineral oil, paraffinic mineral oil, alkylbenzene synthetic oil, and bory α-olefin synthetic oil meet the required conditions. One of the drawbacks of lubricating oil and old 34a is that it does not show solubility.

If Rl34a and lubrication port melt 11 are defective, it will be taken out from the compressor due to entrainment of droplets! ] The lubricating oil is in the condenser,
When separated from the refrigerant in the evaporator, dry A pipe, etc., the viscosity becomes extremely high, resulting in poor return to the compressor, a drop in oil in the compressor, and even sliding. Friction in the department, 77! This is undesirable as it causes problems such as wear and seizure of the compressor.

On the other hand, polyalkylene glycol oil containing alcoholic hydroxyl groups (OI4 groups) has been proposed as a lubricating oil that is soluble in R134a (LISP 4,755
, 316 etc.). However, alcoholic hydroxyl group (OH group)
It is known that substances having the following easily react with lower aliphatic halogenated hydrocarbons and decompose them. As an example, the reaction between trichlorofluoromethane and methanol is shown below, but it is said that the reaction decomposes and produces aldebides and ketones.

CC]. ,F+ CllxOH→Cl{CliF +
IiCIiO+ I! (: IR134a A similar reaction occurs in combination with polyalgylene glycol oil having an alcoholic hydroxyl group. When such decomposition occurs, the hydrogen halide produced as a result of the decomposition causes corrosion of equipment, a decrease in lubrication performance, etc. This is not desirable.

[Means for Solving the Problems] The present invention aims to solve the above-mentioned problems (As a result of repeated studies on lubricating oil for Rl34a compressors, the present inventors have determined that the alcoholic hydroxyl group (ot !base)
The present invention was completed based on the finding in Q5 that it is preferable to improve the compound as shown in the following compound (T).

R-O n'-0: J-C-OR2... (1)
"11 [R is a hydrocarbon group, 1 is an alkylene group, R2 is an alkyl group, n is a viscosity of the above compound (1) is 10 to 300
cst (40°C)] That is, the present invention
34a Compound (I) and old 3 which can prevent friction 1* wear and seizure in the sliding parts of compressed rocks by using the compound (1) as a lubricating oil for compressors
This relates to a compression refrigeration composition consisting of 4a.

The compound (I) in the present invention includes 1 of the compressor.
In order to sufficiently achieve functions such as friction detection, 1" wear and seizure prevention in g-moving parts, the viscosity should be lO~3
It is desirable that the temperature is 00cst (40℃), and the compound (
It is preferable that the molecular weight or the value of n in I) be selected such that the viscosity falls within this range.

R in the compound CI) is a saturated or unsaturated linear or branched hydrocarbon group, preferably having 1 to 10 carbon atoms.
is an alkyl group. As R10, ethylene oxide, brobylene oxide, butylene oxide, etc. are preferable, and brobylene oxide is particularly preferable. Also, these alkylene oxides are 2f! It may be a block or a random combination of combinations of II or more, and in this case it is preferable that the main component is brobylene oxide.
R2 is a linear or branched alkyl group, preferably one having 1 to IO carbon atoms.

The weight ratio of the compound (1) and old 34a is 1/99.9
9/1, 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 , phosphite compounds such as diisopropylphosphite and diphenyl phosphite, phosphine sulfide compounds such as triphenoxyphosphine sulfide and trimethylphosphine sulfide, and other stabilizers such as glycidyl ethers may be added in small amounts.

In addition, naphthenic mineral oils, paraffinic mineral oils, alkylbenzene synthetic oils, poly-α-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.

In addition, various additives such as phenol-based and amine-based antioxidants, sulfur- and phosphorus-based extreme pressure additives, silicone-based antifoaming agents, and metal deactivators such as penzo-1-lyazole may be added to the composition of the present invention. You can also add more to the product.

[Example] Using the compound (I) shown in Tables 1 and 2 below, R1
Solubility and stability tests were conducted with 34a. Compound (I) and I1134a were sealed in a glass ampoule at a weight ratio of 30/70, and the presence or absence of dissolution of compound (1) and Rl34a was determined by observation of meat [11J] depending on the presence or absence of the interface. The results are shown in Table 1 along with comparative examples.

This was confirmed by relative comparison of the degree of deterioration among the combinations shown in Table 1 S. The results are shown in Table 2.
Typical metals SS4 1 and C to S316 pressure containers
Compound (1). R134a
．． The state of metal deterioration was evaluated using conventionally used Rl2 and Suniso 4G naphthenic oil manufactured by Nippon Sun Oil Co., Ltd. (cst, at 40°C) [Effects of the Invention] The composition for compression refrigerators of the present invention is shown in Examples. As is clear from the above, it has good solubility and stability, and is excellent in preventing friction, wear, and seizure in the sliding parts of the compressor.

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 an alkyl group, n is the above compound The viscosity of (I) is 10-30
0 cst (40° C.)] and 1,1,1,2-tetrafluoroethane.