Lubricating oil composition for refrigerators

Abstract

Provided is a lubricating oil composition for a refrigerator which uses a base oil including as the main component at least one kind of oxygen-containing compounds selected from polyoxyalkylene glycols, polyvinyl ethers, copolymers of poly(oxy)alkylene glycols or monoethers thereof and polyvinyl ethers, polyol esters, and polycarbonates. The lubricating oil composition for a refrigerator is used for a refrigerator that uses, as a refrigerant, a fluorine-containing organic compound, which is a refrigerant applicable to current car air conditioner systems or the like and has a specific polar structure, and has favorable sealing property, a low coefficient of friction factor in a sliding part, and excellent stability as well as excellent compatibility with the refrigerant.

1 . A lubricating oil composition for a refrigerator, the refrigerator using a refrigerant comprising at least one kind of fluorine-containing organic compounds selected from compounds represented by the following molecular formula (A) or including a combination of the fluorine-containing organic compound and a saturated fluorinated hydrocarbon compound,
   C p O q F f R s   (A)   
     where: R represents Cl, Br, I, or H; p represents an integer of 1 to 6, q represents an integer of 0 to 2, r represents an integer of 1 to 14, and s represents an integer of 0 to 13; and provided that, when q represents 0, p represents 2 to 6 and one or more carbon-carbon unsaturated bonds are included in the molecule, wherein the composition comprises a base oil including as a main component at least one kind of oxygen-containing compound selected from polyoxyalkylene glycols, polyvinyl ethers, copolymers of poly(oxy)alkylene glycols or monoethers thereof and polyvinyl ethers, polyol esters, and polycarbonates. 
   
   
       2 . A lubricating oil composition for a refrigerator, the refrigerator using a refrigerant comprising at least one kind of fluorine-containing organic compounds selected from a fluorinated ether compound, a fluorinated alcohol compound, and a fluorinated ketone compound, or including a combination of the fluorine-containing organic compound and a saturated fluorinated hydrocarbon compound, wherein the composition comprises a base oil including as a main component at least one kind of oxygen-containing compound selected from polyoxyalkylene glycols, polyvinyl ethers, copolymers of poly(oxy)alkylene glycols or monoethers thereof and polyvinyl ethers, polyol esters, and polycarbonates. 
   
   
       3 . The lubricating oil composition for a refrigerator according to  claim 1 , wherein the base oil has a kinematic viscosity of 2 to 50 mm 2 /s at 100° C. 
   
   
       4 . The lubricating oil composition for a refrigerator according to  claim 1 , wherein the base oil has a number average molecular weight of 500 or more. 
   
   
       5 . The lubricating oil composition for a refrigerator according to  claim 1 , wherein the base oil has a flash point of 150° C. or higher. 
   
   
       6 . The refrigerator oil composition for a refrigerator according to  claim 1 , further comprising at least one kind of an additive selected from an extreme pressure agent, an oiliness agent, an antioxidant, an acid scavenger, and an anti-foaming agent. 
   
   
       7 . The lubricating oil composition for a refrigerator according to  claim 1 , wherein the fluorine-containing organic compound in the refrigerant is a fluorinated dimethyl ether. 
   
   
       8 . The lubricating oil composition for a refrigerator according to  claim 1 , wherein the fluorine-containing organic compound in the refrigerant is a fluorinated methyl alcohol. 
   
   
       9 . The lubricating oil composition for a refrigerator according to  claim 1 , wherein the fluorine-containing organic compound in the refrigerant is a fluorinated acetone. 
   
   
       10 . The lubricating oil composition for a refrigerator according to  claim 1 , wherein the saturated fluorinated hydrocarbon compound in the refrigerant is at least one kind selected from 1,1-difluoroethane, trifluoroethane, tetrafluoroethane, and pentafluoroethane. 
   
   
       11 . The lubricating oil composition for a refrigerator according to  claim 1 , wherein a sliding part in a refrigerator is formed of an engineering plastic or includes an organic coating film or an inorganic coating film. 
   
   
       12 . The lubricating oil composition for a refrigerator according to  claim 11 , wherein the organic coating film is a polytetrafluoroethylene coating film, a polyimide coating film, or a polyamideimide coating film. 
   
   
       13 . The lubricating oil composition for a refrigerator according to  claim 11 , wherein the inorganic coating film is a graphite film, a diamond-like carbon film, a tin film, a chromium film, a nickel film, or a molybdenum film. 
   
   
       14 . The lubricating oil composition for a refrigerator according to  claim 1 , which is used in a car air conditioner, an electrically-driven car air conditioner, a gas heat pump, an air conditioner, a cold storage, various hot-water supply systems for a vending machine or a showcase, or a refrigerating and heating system. 
   
   
       15 . The lubricating oil composition for a refrigerator according to  claim 14 , wherein the water content in such a system is 300 mass ppm or less and a residual air content in the system is 10 kPa or less.