Working fluid composition for refrigerating machine

Claim 2

A working fluid composition for refrigerating machine comprising: a hydrofluorocarbon and a refrigeration oil prepared by adding a compound having an epoxycyclohexyl group and/or a compound having an epoxycyclopentyl group to an ester formed between a neopentylpolyol and a saturated branched aliphatic monocarboxylic acid having a carbon number of 7 to 9 in a ratio of 0.05 to 2.0 parts by weight to 100 parts by weight of the ester.

Claim 3

A working fluid composition for refrigerating machine comprising: a hydrofluorocarbon and a refrigeration oil prepared by adding a compound having an epoxycyclohexyl group and/or a compound having an epoxycyclopentyl group to an ester formed between a neopentylpolyol and a saturated branched aliphatic monocarboxylic acid having a carbon number of 7 to 9 in a ratio of 0.05 to 2.0 parts by weight to 100 parts by weight of the ester and adding at least one compound selected from the group consisting of a triaryl phosphate and/or a triaryl phosphite in a ratio of 0.1 to 5.0 parts by weight, a benzotriazole and/or a benzotriazole derivative in a ratio of 0.001 to 0.1 parts by weight and a metal deactivator capable of chelating in a ratio of 0.001 to 2.0 parts by weight to 100 parts by weight of the ester.

Claim 4

A working fluid composition for refrigerating machine according to claims 1, 2 or 3, wherein said ester is formed between trihydric and higher polyhydric neopentylpolyol and a carboxylic acid containing a saturated branched aliphatic monocarboxylic acid and wherein at least 70% by weight of the acid used to form esters has a carbon number of 7 to 9 and wherein at least 25% by weight of the acid used to form esters is 2-methylhexanoic acid.

Claim 5

A working fluid composition for refrigerating machine according to claims 1, 2 or 3, wherein said ester is formed between dihydric neopentylpolyol and a carboxylic acid containing 2-methylhexanoic acid at not less than 70% by weight of the total carboxylic acid content.

Claim 6

A working fluid composition for refrigerating machine according to claim 4, wherein said saturated branched aliphatic monocarboxylic acid is 2-methylhexanoic acid alone.

Claim 7

A working fluid composition for refrigerating machine according to claim 4, wherein said saturated branched aliphatic monocarboxylic acid is a mixed acid comprising 2-methylhexanoic acid and at least one acid selected from the group consisting of 2-ethylhexanoic acid, 3,5-dimethylhexanoic acid and 3,5,5-trimethylhexanoic acid.

Claim 8

A working fluid composition for refrigerating machine according to claim 4, wherein said trihydric and higher polyhydric neopentylpolyol is trimethylolpropane and/or pentaerythritol.

Claim 9

A working fluid composition for refrigerating machine according to claim 5, wherein said dihydric neopentylpolyol is neopentyl glycol.

Claim 10

A working fluid composition for refrigerating machine according to claims 1, 2 or 3, wherein said ester is formed between 2-methylhexanoic acid and trimethylolpropane and/or pentaerythritol.

Claim 11

A working fluid composition for refrigerating machine according to claims 1, 2 or 3, wherein said ester is formed between 2-methylhexanoic acid and neopentyl glycol.

Claim 12

A working fluid composition for refrigerating machine according to claims 1, 2 or 3, wherein the hydroxyl value of the ester is 1 to 50 mg KOH/g.

Claim 13

A working fluid composition for use in a refrigeration cycle comprising: a hydrofluorocarbon; and an ester composition, wherein said ester composition comprises an ester formed by condensing a neopentylpolyol and a saturated branched aliphatic monocarboxylic acid having a carbon number of 7 to 9.

Claim 14

A process of refrigeration comprising subjecting a working fluid to a refrigeration cycle, wherein the working fluid is the working fluid of claim 13.

Claim 15

In a process for refrigeration utilizing a working fluid that is subjected to repeated refrigeration cycles, the improvement for which comprises using the working fluid of claim 13 as the working fluid.

Claim 16

Use of a composition comprising: a hydrofluorocarbon and an ester formed between a neopentylpolyol and a saturated branched aliphatic monocarboxylic acid having a carbon number of 7 to 9, as a working fluid composition for refrigerating machine.