Lubricating oil for refrigerator

A lubricating oil for a refrigerator using a hydrofluorocarbon refrigerant, the oil comprising an ester of dipentareythritol or tripentaerythritol with an aliphatic monobasic acid having 3 to 7 carbon atoms, or mixtures thereof, and an organic carboxylic acid ester having viscosity different from that of said ester, or a polymer selected from polyalkyl-methacrylate, polyester or neopentylglycol with a fatty acid, the oil having a viscosity at 100.degree. C. in the range of 7 to 30 mm.sup.2 /s.

A lubricating oil for a refrigerator using a hydrofluorocarbon refrigerant, the oil comprising a sulfur type anti-wear agent and an ester of dipentaerythritol or tripentaerythritol with an aliphatic monobasic acid having 3 to 7 carbon atoms, or mixtures thereof, the oil having a viscosity at 100.degree. C. in the range of 7 to 30 mm.sup.2 /s.

A lubricating oil for a refrigerator using a hydrofluorocarbon refrigerant, the oil comprising an ester of an aliphatic monohydric alcohol with an aromatic dibasic acid, or mixtures thereof, the oil having a viscosity at 100.degree. C. in the range of 2 to 30 mm.sup.2 /s.

A lubricating oil for a refrigerator using hydrofluorocarbon refrigerant, the oil comprising an ester of an aliphatic monohydric alcohol with an aromatic dibasic acid, or mixtures thereof, and an organic carboxylic acid ester having viscosity different from that of said ester, or a polymer selected from polyalkyl-methacrylate, polyalkyleneglycol and a polyester of neopentylglycol with a fatty acid, the oil having a viscosity at 100.degree. C. in the range of 2 to 30 mm.sup.2 /s.

A lubricating oil for a refrigerator using a hydrofluorocarbon refrigerant, the oil comprising of a sulfur type anti-wear agent and an ester of an aliphatic monohydric alcohol with an aromatic dibasic acid, or mixtures thereof, the oil having a viscosity at 100.degree. C. in the range of 2 to 30 mm.sup.2 /s.

A lubricating oil for a refrigerator using a hydrofluorocarbon refrigerant, the oil comprising a complex ester of an aliphatic polyhydric alcohol with a polybasic acid selected from aliphatic dibasic acids, aromatic dibasic acids, aromatic tribasic acids, aromatic tetrabasic acids and aliphatic monobasic acids having 3 to 12 carbon atoms, or mixtures thereof, the oil having viscosity at 100.degree. C. in the range of 2 to 30 mm.sup.2 /s.

A lubricating oil for a refrigerator using a hydrofluorocarbon refrigerant, the oil comprising a complex ester of an aliphatic polyhydric alcohol with a polybasic acid selected from aliphatic dibasic acids, aromatic dibasic acids, aromatic tribasic acids, aromatic tetrabasic acids and aliphatic monobasic acids having 3 to 12 carbon atoms, or mixtures thereof, and an organic carboxylic acid ester having viscosity different from that of the complex ester, or a polymer selected from polyalkylmethacrylate, polyalkyleneglycol and a polyester of neopentylglycol with a fatty acid, the oil having a viscosity at 100.degree. C. in the range of 2 to 30 mm.sup.2 /s.

A lubricating oil for a refrigerator using a hydrofluorocarbon refrigerant, the oil comprising a complex ester of an aliphatic polyhydric alcohol with a polybasic acid selected from aliphatic dibasic acids, aromatic dibasic acids, aromatic tribasic acids, aromatic tetrabasic acids and aliphatic monobasic acids having 3 to 12 carbon atoms, or mixtures thereof, and a sulfur type anti-wear agent, the oil having viscosity at 100.degree. C. in the range of 2 to 30 mm.sup.2 /s.

A lubricating oil for a refrigerator using a hydrofluorocarbon refrigerant, the oil consisting of an ester of a polyoxyalkyleneglycol, the oil consisting of an ester of a polyoxyalkyleneglycol monoether with a dicarboxylic acid given by the following general formula (A), or mixtures thereof, or an ester of a polyoxyalkylene addition derivative of trimethylolalkane given by the following general formula (B), or mixtures thereof, the oil having a viscosity at 100.degree. C. in the range of 2 to 30 mm.sup.2 /s, wherein general formula (A) is:

• ##STR4## where R.sup.1 or R.sup.5 each represents an alkyl group having 1 to 8 carbon atoms, and these may be identical to or different from each other, R.sup.2 or R.sup.4 each represents an alkylene group having 2 to 6 carbon atoms, R.sup.3 represents an alkylene group or aromatic ring having 2 to 8 carbon atoms and m or n represents an integer of 2 or more, and general formula (B) is:
• ##STR5## where R.sup.1 represent an alkyl group having 1 to 8 carbon atoms, R.sup.2, R.sup.3 or R.sup.4 each represents an alkylene group having 2 to 6 carbon atoms, R.sup.5, R.sup.6 or R.sup.7 each is an acyl group having 3 to 10 carbon atoms, and these may be identical to or different from each other, and p, q or r is an integer of 1 or more.

A lubricating oil for a refrigerator using a hydrofluorocarbon refrigerant, the oil consisting of an ester of polyoxy alkyleneglycol monoether with a carboxylic acid given by the following general formula (A), or mixtures thereof, or an ester of polyoxyalkylene addition derivative of trimethylolalkane given by the following general formula (B), or mixtures thereof, and a sulfur type anti-wear agent, the oil having viscosity at 100.degree. C. in the range of 2 to 30 mm.sup.2 /s, wherein general formula (A) is:

• ##STR8## where R.sup.1 or R.sup.5 each represents an alkyl group having 1 to 8 carbon atoms, and these may be identical to or different from each other, R.sup.2 or R.sup.4 each represents an alkylene 2 group having 2 to 6 carbon atoms, R.sup.3 represents an alkylene group or aromatic ring having 2 to 8 carbon atoms, and m or n represents an integer of 2 or more, and general formula (B) is:
• ##STR9## where R.sup.1 represent an alkyl group having 1 to 8 carbon atoms, R.sup.2, R.sup.3 or R.sup.4 each represents an alkylene group having 2 to 6 carbon atoms, R.sup.5, R.sup.6 or R.sup.7 each is an acyl group having 3 to 10 carbon atoms, and these may be identical to or different from each other, and p, q or r is an integer of 1 or more.