Refrigeration working fluid compositions
OwnerRichard Henry Schlosberg, David Wayne Turner +2inventors
InventorsRichard Henry Schlosberg, David Wayne Turner, Shlomo Antika, Martin Anthony Krevalis JR.
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Abstract
There are disclosed refrigeration working fluid compositions comprising tetrafluoroethane refrigerants and certain polyol esters of C7-C10 branched alkanoic acids or mixtures of such branched acids with linear C7-C10 monoalkanoic acids. The polyols are mono-, di- or technical grade pentaerythritol or trimethylolpropane; the esters exhibit suitable viscosity ranges and miscibility with refrigerants over a broad compositional range. The acids have a defined average effective carbon chain length and a certain degree of methyl branching for polyols other than trimethylolpropane.
Claims17
A refrigeration working fluid comprising about 5-55 parts by weight of a synthetic ester lubricant and about 95-45 parts by weight of a tetrafluoroethane refrigerant, the ester having a viscosity range of from about 26 cSt. to 114 cSt. at 40° C. and the working fluid having a miscibility value of −20° C. or less, where the ester is prepared by reacting monopentaerythritol with (a) a branched C7 -C10 alkyl monocarboxylic acid or (b) a mixture of up to 73% by weight of a linear C7-C10 alkyl monocarboxylic acid and 27% by weight or more of a branched C7-C10 alkyl monocarboxylic acid, said branched acid containing 50% or more of branched methyl groups based on the total number of branched alkyl groups in the acid molecule and said branched acid or acid mixture having an average effective carbon chain length equal to or less than 6.2.
A. refrigeration working fluid comprising about 5-55 parts by weight of a synthetic ester lubricant and about 95-45 parts by weight of a tetrafluoroethane refrigerant, the ester having a viscosity range of from about 27 cSt. to 130 cSt. at 40° C., and the working fluid having a miscibility value of −20° C. or less, wherein the ester is prepared by reacting technical grade pentaerythritol with (a) a branched C7-C10 alkyl monocarboxylic acid or (b) a mixture of up to 67% by weight of a linear C7-C10 alkyl monocarboxylic acid and 33% by weight or more of a branched C7-C10 monocarboxylic acid, said branched acid containing 50% or more of branched methyl groups based on the total number of branched alkyl groups in the acid molecule and said branched acid or acid mixture having an average effective carbon chain length equal to or less than 6.0, and said technical grade pentaerythritol containing 85-92% by weight monopentaerythritol, 14-7% by weight dipentaerythritol and up to 2% by weight tripentaerythritol.
A refrigeration working fluid comprising about 5-55 parts by weight of a synthetic ester lubricant and about 95-45 parts by weight of a tetrafluoroethane refrigerant, the ester having a viscosity range of from about 10 cSt. to 55 cSt. at 40° C. and the working fluid having a miscibility value of −20° C. or less, wherein the ester is prepared by reacting trimethylolpropane with (a) a branched C7-C10 alkyl monocarboxylic acid and (b) a mixture of up to 85% by weight of a linear C7-C10 alkyl monocarboxylic acid and 15% or more of a branched C7-C10 alkyl monocarboxylic acid, and said branched acid or acid mixture having an effective carbon chain length equal to or less than 7.0.
A refrigeration working fluid composition comprising about 5-55 parts by weight of a synthetic ester lubricant and about 95-45 parts by weight of a tetrafluoroethane refrigerant, the ester having a viscosity of from 80 cSt. to 120 cSt. at 40° C. and the working fluid having a miscibility value of −15° C. or less, where the ester is prepared by reacting dipentaerythritol with (a) a branched C7-C10 alkyl monocarboxylic acid or (b) a mixture of 90% by weight or more of a branched C7-C10 alkyl monocarboxylic acid and up to 10% by weight of a linear C7-C10 alkyl monocarboxylic acid, said branched acid containing 50% or more branched methyl groups based on the total number of branched alkyl groups in the acid molecule and said branched acid or acid mixture having an average effective carbon chain length equal to or less than 5.7.
Refrigeration working fluid comprising about 5-55 parts by weight of a synthetic ester lubricant and 95-45 parts by weight of a tetrafluoroethane refrigerant, the lubricant being a mixture of two or more esters of the group consisting of:
- a) esters of monopentaerythritol with (i) a branched C7-C10 alkyl monocarboxylic acid or (ii) a mixture of up to 73 wt % of a linear C7-C10 alkyl monocarboxylic acid and 27 wt % of a branched C7-C10 monocarboxylic acid, said branched acid having an average effective carbon chain length equal to or less than 6.2,
- b) esters of technical grade pentaerythritol with (i) a branched C7-C10 alkyl monocarboxylic or (ii) a mixture of up to 67 wt % of a linear C7-C10 alkyl monocarboxylic acid and 33 wt % or more of a branched C7-C10 alkyl monocarboxylic acid, said branched acid having an average effective carbon chain length equal to or less than 6.0,
- c) esters of trimethylolpropane with (i) a branched C7-C10 alkyl monocarboxylic acid or (ii) a mixture of up to 85 wt % of a linear C7-C10 alkyl monocarboxylic acid and 15 wt % or more of a branched C7-C10 alkyl monocarboxylic acid, the branched acid having an average effective carbon chain length equal to or less than 7.0, and
- d) esters of dipentaerythritol with (i) a branched C7-C10 alkyl monocarboxylic acid or (ii) a mixture of up to 10 wt % of a linear C7-C10 alkyl monocarboxylic acid and 90 wt % or more of a branched C7-C10 alkyl monocarboxylic acid, the branched acid having an average effective carbon chain length equal to or less than 5.7,
- with the proviso that said branched acid contains 50% or more methyl branches, based on the total alkyl branches in the acid molecule, when said mixture contains said pentaerythritol, technical grade pentaerythritol or dipentaerythritol esters, and said working fluid has a miscibility value of −20° C. or lower for said mixtures containing only monopentaerythritol, technical grade pentaerythritol and trimethylolpropane esters and a miscibility value of −15° C. or lower when said mixtures contain dipentaerythritol, and the viscosity of said ester mixture is from 10 cSt. to 130 cSt. at 40° C.
Dependencies are inferred from the claim text.