Lubricant oil composition for compression refrigerator

Abstract

It is to provide a lubricating oil composition for a compression refrigerator, which is excellent in the thermal/chemical stability even when used in a compression refrigerator that uses a saturated fluorinated hydrocarbon refrigerant having a lower global warming potential and a fewer carbon atoms, by including in a base oil an organic compound having a double bond in a molecule, which is at least one kind selected from an organic compound having at least two non-conjugated double bonds in the molecule, a terpene compound having a double bond in the molecule, and C 12 to C 30 aliphatic unsaturated hydrocarbon having one double bond in the molecule.

1 . A lubricating oil composition, comprising:
 a base oil; and   an organic compound having a double bond, which is at least one kind selected from the group consisting of an organic compound having at least two non-conjugated double bonds, a terpene compound having a double bond, and a C 12  to C 30  aliphatic unsaturated hydrocarbon having one double bond,   wherein the lubricating oil composition is suitable for a compression refrigerator and   the compression refrigerator comprises a refrigerant comprising a C 1  to C 3  saturated fluorinated hydrocarbon.   
     
     
         2 . The lubricating oil composition according to  claim 1 , wherein the organic compound having a double bond has, as an organic compound having at least two non-conjugated double bonds, a 1,4-diene structure. 
     
     
         3 . The lubricating oil composition according to  claim 1 , wherein the organic compound having a double bond has. as an organic compound having at least two non-conjugated double bonds, a bridged cyclic structure. 
     
     
         4 . The lubricating oil composition according to  claim 1 , wherein the organic compound having a double bond, as a terpene compound, is a pinene compound. 
     
     
         5 . The lubricating oil composition according to  claim 1 , wherein the lubricating oil composition comprises the organic compound having a double bond in an amount of from 0.1% by mass to 10% by mass or less based on a total amount of the lubricating oil composition. 
     
     
         6 . The lubricating oil composition according to  claim 1 , wherein the C 1  to C 3  saturated fluorinated hydrocarbon is difluoromethane. 
     
     
         7 . The lubricating oil composition according to  claim 1 , wherein the refrigerant is a mixture of difluoromethane and pentafluoroethane, or a mixture of difluoromethane, pentafluoroethane, and 1,1,1,2 tetrafluoroethane. 
     
     
         8 . The lubricating oil composition according to  claim 7 , wherein the refrigerant comprises difluoromethane in an amount of 20% by mass or more. 
     
     
         9 . The lubricating oil composition according to  claim 1 , wherein the base oil comprises at least one selected from the group consisting of a polyoxyalkylene glycol, a polyvinyl ether, a copolymer of a polyoxyalkylene glycol and a polyvinyl ether, a copolymer of a polyoxyalkylene glycol monoether and a polyvinyl ether, a polyol ester and a polycarbonate as a main component. 
     
     
         10 . The lubricating oil composition according to  claim 1 , wherein the base oil has a kinematic viscosity of from 1 mm 2 /s to 50 mm 2 /s at 100° C. 
     
     
         11 . The lubricating oil composition according to  claim 1 , wherein the base oil has a number average molecular weight of from 300 to 3000. 
     
     
         12 . The lubricating oil composition according to  claim 1 , wherein the base oil has a viscosity index of 60 or more. 
     
     
         13 . The lubricating oil composition according to  claim 1 , further comprising:
 at least one additive selected from the group consisting of an extreme pressure agent, an oiliness agent, an antioxidant, an acid scavenger, a metal deactivator, and an antifoaming agent.   
     
     
         14 . The lubricating oil composition according to  claim 1 , wherein the compression refrigerator comprises a sliding part comprising an engineering plastic, an organic coating film, or an inorganic coating film. 
     
     
         15 . The lubricating oil composition according to  claim 14 ,
 wherein the sliding part comprises, as an organic coating film, a polytetrafluoroethylene coating film, a polyimide coating film, a polyamideimide coating film, a thermosetting insulating film, or any combination thereof,   wherein if the sliding member comprises the thermosetting insulating film, the thermosetting insulating film is obtained from a resin coating material comprising a resin base material and a crosslinking agent and   if the sliding member comprises the thermosetting insulating film, the resin base material comprising a polyhydroxy ether resin and a polysulfonic resin.   
     
     
         16 . The lubricating oil composition according to  claim 14 , wherein the sliding part comprises, as an inorganic coating film, a graphite film, a diamond-like carbon film, a tin film, a chromium film, a nickel film, a molybdenum film, or any combination thereof. 
     
     
         17 . The lubricating oil composition according to  claim 1 , wherein the lubricating oil composition is suitable for a car air conditioner, an electric car air conditioner, a gas heat pump, an air conditioner, a refrigerator, an automatic vending machine, a show case, a hot-water supply system, a freezing and heating system, or any combination thereof. 
     
     
         18 . The lubricating oil composition according to  claim 17 , wherein the lubricating oil composition is suitable for the hot-water supply system having a moisture content of 300 ppm by mass or less and a residual air partial pressure of 10 kPa or less. 
     
     
         19 . The lubricating oil composition according to  claim 17 , wherein the lubricating oil composition is suitable for the freezing and heating system having a moisture content of 300 ppm by mass or less and a residual air partial pressure of 10 kPa or less.