Compositions – Vaporization – or expansion – refrigeration or heat or energy... – With lubricants – or warning – stabilizing or anti-corrosion...
Reexamination Certificate
1999-01-15
2001-10-09
Einsmann, Margaret (Department: 1751)
Compositions
Vaporization, or expansion, refrigeration or heat or energy...
With lubricants, or warning, stabilizing or anti-corrosion...
C252S067000
Reexamination Certificate
active
06299792
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to compositions containing polymeric oil-return agents which solubilize or disperse mineral and synthetic oil lubricants with halogenated hydrocarbon refrigerants, permitting efficient return of lubricants from non-compressor zones back to a compressor zone in a refrigeration system.
BACKGROUND OF THE INVENTION
Mineral oils and alkylbenzenes have been conventionally used as lubricants in chlorofluorocarbon-based (CFC) refrigeration systems. However, the lack of solubility of these lubricants in the replacement, non-ozone depleting, hydrofluorocarbon (HFC) refrigerants has precluded their use and necessitated development and use of alternative lubricants for HFC refrigeration systems based on polyalkylene glycols (PAGs) and polyol esters (POEs). While the PAGs and POEs are suitable lubricants for HFC-based refrigeration systems, they are extremely hygroscopic and can absorb several thousand ppm (parts per million) of water on exposure to moist air. This absorbed moisture leads to problems in the refrigeration system, such as formation of acids which resultant in corrosion of the refrigeration system and formation of intractable sludges. In contrast, mineral oils and alkylbenzenes are much less hygroscopic and have low solubility, less than 100 ppm, for water. Additionally, PAG and POE lubricants are considerably more expensive than the hydrocarbon lubricants, typically on the order of three to six times more expensive. As a consequence, there is a need and an opportunity to resolve this solubility problem so that the refrigeration industry may utilize mineral oil and alkylbenzene lubricants with HFC-based refrigerants.
Hydrochlorofluorocarbon (HCFC) refrigerants are also replacing CFCs, and in instances as mixtures with HFCs. These HCFC-based refrigerant mixtures are less soluble than CFCs in conventional refrigeration lubricants such as mineral oil. A lubricant change from mineral oil to alkylbenzene is often required when the HCFCs or HCFC/HFC mixtures are used to replace pure CFC-based based refrigerants, resulting in more expense to the refrigeration industry. Consequently, there is a need and opportunity to resolve this low solubility problem so that the refrigeration industry may utilize HCFC and HCFC/HFC-based refrigerants with mineral oil lubricants.
The present invention addresses these needs of the refrigeration industry by providing polymeric oil-return agents which create a solution or stabilized dispersion of lubricant oil (dispersed phase) in a HFC- and/or HCFC-based refrigerant (continuous phase), permitting improved lubricant oil transport through a refrigeration system and lubricant oil return back to the refrigeration system compressor from other refrigeration system zones.
SUMMARY OF THE INVENTION
The present invention relates to refrigerant compositions comprising: (a) a halogenated hydrocarbon containing at least one carbon atom and one fluorine atom; (b) an oil selected from the group consisting of mineral oils and synthetic oils; and (c) an effective amount of polymeric oil-return agent, wherein said oil-return agent forms a solution or stabilized dispersion of said halogenated hydrocarbon and said oil, and wherein said oil-return agent comprises less than about 10 weight percent of said refrigerant composition. The polymeric oil-return agents of the present invention solubilize or disperse mineral and synthetic oil lubricants with halogenated hydrocarbon refrigerants. The polymeric oil-return agents, as a small proportion of an overall refrigerant composition, permit efficient return of mineral and synthetic oil lubricants from non-compressor zones back to a compressor zone in a refrigeration system.
DETAILED DESCRIPTION
The present invention relates to refrigerant compositions comprising:
(a) a halogenated hydrocarbon containing at least one carbon atom and one fluorine atom;
(b) an oil selected from the group consisting of mineral oils and synthetic oils; and
(c) an effective amount of polymeric oil-return agent, wherein said oil-return agent forms a solution or stabilized dispersion of said halogenated hydrocarbon and said oil, and wherein said oil-return agent comprises less than about 10 weight percent of said refrigerant composition.
The present invention further relates to compositions, comprising:
(a) a halogenated hydrocarbon containing at least one carbon atom and one fluorine atom; and
(b) an effective amount of polymeric oil-return agent, wherein said oil-return agent forms a solution or a stabilized dispersion of said halogenated hydrocarbon with an oil comprising mineral oils and synthetic oils.
The present invention further relates to lubricant compositions for use with halogenated hydrocarbon refrigerant, comprising:
(a) an oil selected from the group consisting of mineral oils and synthetic oils; and
(b) an effective amount of polymeric oil-return agent, wherein said oil-return agent forms a solution or stabilized dispersion of said oil with a halogenated hydrocarbon refrigerant.
Halogenated hydrocarbons of the present invention contain at least one carbon atom and one fluorine atom. Of particular utility are halogenated hydrocarbons having 1-6 carbon atoms containing at least one fluorine atom, optionally containing chlorine and oxygen atoms, and having a normal boiling point of from −90° C. to 80° C. By normal boiling point is meant the temperature at which a liquid composition's vapor pressure is equal to one atmosphere. These halogenated hydrocarbons may be represented by the general formula C
w
F
2w+2−x−y
H
x
Cl
y
O
z
, wherein w is 1−6, x is 1−9, y is 0-3, and z is 0−2. Preferred of the halogenated hydrocarbons are those in which w is 1−6, x is 1−5, y is 0−1, and z is 0−1. Such halogenated hydrocarbons are commercial products available from a number of sources such as E. I. du Pont de Nemours & Co., Fluoroproducts, Wilmington, Del., 19898, USA, or are available from custom synthesis companies such as PCR Inc., P.O. Box 1466, Gainesville, Fla., 32602, USA, and additionally by synthetic processes disclosed in art such as The Journal of Fluorine Chemistry, or Chemistry of Organic Fluorine Compounds, edited by Milos Hudlicky, published by The MacMillan Company, New York, N.Y., 1962. Examples are: CCl
2
F
2
(CFC-12), CHCl
2
F (HCFC-21), CHClF
2
(HCFC-22), CHF
3
(HFC-23), CH
2
ClF (HCFC-31), CH
2
F
2
(HFC-32), CH
3
F (HFC-41), CHCl
2
CF3 (HCFC-123), CHClFCClF
2
(HCFC-123a), CHCIFCF
3
(HCFC-124), CHF
2
CCIF
2
(HCFC-124a), CHF
2
CF
3
(HFC-125), CH
2
ClCF
3
(HCFC-133a), CHF
2
CHF
2
(HFC-134), CH
2
FCF
3
(HFC-134a), CClF
2
CH
3
(HCFC-142b), CHF
2
CH
2
F (HFC-143), CF
3
CH
3
(HFC-143a), CHCIFCH
3
(HCFC-151a), CHF
2
CH
3
(HFC-152a), CHF
2
CCl
2
CF
3
(HCFC-225aa), CHCIFCCIFCF
3
(HCFC-225ba), CHF
2
CClFCClF
2
(HCFC-225bb), CHCI
2
CF
2
CF
3
(HCFC-225ca), CHCIFCF
2
CCIF
2
(HCFC-225cb), CHF
2
CF
2
CCl
2
F (HCFC-225cc), CClF
2
CHClCF
3
(HCFC-225da), CClF
2
CHFCCIF
2
(HCFC-225ea), CF
3
CHFCCl
2
F (HCFC-225eb), CHF
2
CCIFCF
3
(HCFC-226ba), CHClFCF
2
CF
3
(HCFC-226ca), CHF
2
CF
2
CCIF
2
(HCFC-226cb), CF
3
CHClCF
3
(HCFC-226da), CClF
2
CHFCF
3
(HCFC-226ea), CHF
2
CF
2
CF
3
(HFC-227ca), CF
3
CFHCF
3
(HFC-227ea), CHF
2
CClFCHF
2
(HCFC-235ba), CH
2
FCCIFCF
3
(HCFC-235bb), CHCIFCF
2
CHF
2
(HCFC-235ca), CH
2
ClCF
2
CF
3
(HCFC-235cb), CH
2
FCF
2
CCIF
2
(HCFC-235cc), CHF
2
CHCICF
3
(HCFC-235da), CHCIFCHFCF
3
(HCFC-235ea), CHF
2
CHFCCIF
2
(HCFC-235eb), CClF
2
CH
2
CF
3
(HCFC-235fa), CHFCF
2
CHF
2
(HFC-236ca), CH
2
FCF
2
CF
3
(HFC-236cb), CIF
2
CHFCF
3
(HFC-236ea), CF
3
CH
2
CF
3
(HFC-236fa), CH
2
FCF
2
CHF
2
(HFC-245ca), CH
3
CF
2
CF
3
(HFC-245cb), CHF
2
CHFCHF
2
(HFC-245ea), CH
2
FCHFCF
3
(HFC-245eb), CHF
2
CH
2
CF
3
(HFC-245fa), CH
2
FCF
2
CH
2
F (HFC-254ca), CH
2
CF
2
CHF
2
(HFC254cb), CH
2
FCHFCHF
2
(C-254ea), CH
3
CHFCF
3
(HFC-254eb), CHF
2
CH
2
CHF
2
(BFC-254fa), CH
2
FCH
2
CF
3
(HFC-254fb), CH
3
CF
2
CH
3
(HFC272ca), CH
3
CHFCH
2
F (HFC-272ea), CH
2
FCH
2
CH
2
F (HFC-272fa), CH
3
Feiring Andrew Edward
Lin Lois Lo-I
Minor Barbara Haviland
Shealy Glenn Scott
Spauschus Ann Hosley
E. I. Du Pont de Nemours and Company
Einsmann Margaret
Spauschus Ann Hosley
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