U.S. patent application number 17/342468 was filed with the patent office on 2022-01-06 for azeotrope-like compositions of 1,1,1,2-tetrafluoropropene and 1,1,1,2-tetrafluoroethane.
This patent application is currently assigned to HONEYWELL INTERNATIONAL INC.. The applicant listed for this patent is HONEYWELL INTERNATIONAL INC.. Invention is credited to Ryan Hulse, Hang T. Pham, Christopher J. Seeton, Rajiv R. Singh, Mark W. Spatz, David P. Wilson, Samuel F. Yana Motta.
Application Number | 20220001346 17/342468 |
Document ID | / |
Family ID | |
Filed Date | 2022-01-06 |
United States Patent
Application |
20220001346 |
Kind Code |
A1 |
Seeton; Christopher J. ; et
al. |
January 6, 2022 |
AZEOTROPE-LIKE COMPOSITIONS OF 1,1,1,2-TETRAFLUOROPROPENE AND
1,1,1,2-TETRAFLUOROETHANE
Abstract
Provided are azeotrope-like compositions consisting essentially
of 1,1,1,2-tetrafluoropropene and 1,1,1,2-tetrafluoroethane and
uses thereof, including use in refrigerant compositions,
refrigeration systems, blowing agent compositions, and aerosol
propellants.
Inventors: |
Seeton; Christopher J.;
(East Amherst, NY) ; Pham; Hang T.; (Amherst,
NY) ; Singh; Rajiv R.; (Getzville, NY) ;
Hulse; Ryan; (Getzville, NY) ; Spatz; Mark W.;
(East Amherst, NY) ; Wilson; David P.; (Amherst,
NY) ; Yana Motta; Samuel F.; (East Amherst,
NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HONEYWELL INTERNATIONAL INC. |
Charlotte |
NC |
US |
|
|
Assignee: |
HONEYWELL INTERNATIONAL
INC.
Charlotte
NC
|
Appl. No.: |
17/342468 |
Filed: |
June 8, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15355907 |
Nov 18, 2016 |
11027249 |
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17342468 |
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12542185 |
Aug 17, 2009 |
9546311 |
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15355907 |
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61089986 |
Aug 19, 2008 |
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International
Class: |
B01F 17/00 20060101
B01F017/00; C09K 5/04 20060101 C09K005/04; A61K 8/04 20060101
A61K008/04; A61K 8/70 20060101 A61K008/70; A61Q 19/00 20060101
A61Q019/00; C08J 9/14 20060101 C08J009/14; C09K 3/30 20060101
C09K003/30; C11D 7/50 20060101 C11D007/50; A61K 9/12 20060101
A61K009/12; A61Q 5/06 20060101 A61Q005/06; A61Q 15/00 20060101
A61Q015/00; C09K 3/00 20060101 C09K003/00 |
Claims
1. An azeotrope-like composition consisting essentially of
effective amounts of 1,1,1,2-tetrafluoropropene and
1,1,1,2-tetrafluoroethane to form an azeotrope-like
composition.
2. The azeotrope-like composition of claim 1 which consists
essentially of from greater than zero to about 60 weight percent
1,1,1,2-tetrafluoroethane and from about 40 to less than 100 weight
percent of 1,1,1,2-tetrafluoropropene.
3. The azeotrope-like composition of claim 1 which consists
essentially of from about 10 to about 50 weight percent
1,1,1,2-tetrafluoroethane and from about 50 to less than 90 weight
percent of 1,1,1,2-tetrafluoropropene.
4. The azeotrope-like composition of claim 1 which consists
essentially of from about 20 to about 45 weight percent
1,1,1,2-tetrafluoroethane and from about 55 to about 80 weight
percent of 1,1,1,2-tetrafluoropropene.
5. The azeotrope-like composition of claim 1 having a boiling point
of from about -30.0.degree. C. to about -29.0.degree. C. at a
pressure of about 14.3 psia.
6. A sprayable composition comprising a material to be sprayed and
a propellant comprising an azeotrope-like composition of claim
1.
7. A sprayable composition according to claim 6 wherein the
material to be sprayed comprises a drug, a biologically active
material, a deodorant, a perfume, a hair spray, a cleanser, a wax,
a defluxing agent, a polishing agent, a room freshener, an
insecticide, a cooking oil, or combinations thereof.
8. A refrigerant composition comprising the azeotrope-like
composition of claim 1.
9. A method for cooling an article which comprises condensing a
refrigerant composition of claim 8 and thereafter evaporating said
refrigerant composition in the vicinity of the article to be
cooled.
10. A method for heating an article which comprises condensing a
refrigerant composition of claim 8 in the vicinity of the article
to be heated and thereafter evaporating said refrigerant
composition.
11. A blowing agent comprising an azeotrope-like composition of
claim 1.
12. A foam premix composition comprising a polyol and blowing agent
of claim 11.
13. A foam comprising a plurality of polymeric cells and a
composition contained in at least one of said cells, said
composition comprising a blowing agent of claim 11.
14. A foamable composition comprising the azeotrope-like
composition of claim 1 and at least one thermoset foam
component.
15. The foamable composition of claim 14, wherein said at least one
thermoset component comprises a composition capable of forming a
polyurethane foam, a phenolic foam, or a polyisocyanurate foam.
16. A foamable composition comprising the azeotrope-like
composition of claim 1 and at least one thermoplastic foam
component.
17. The foamable composition of claim 16 wherein said thermoplastic
foam component comprises a polystyrene, polyethylene,
polypropylene, polyethyleneterephthalate, and combinations of
these.
18. A method of recharging a refrigerant system that contains a
refrigerant to be replaced and a lubricant comprising the steps of:
(a) removing the refrigerant to be replaced from the refrigeration
system while retaining a substantial portion of the lubricant in
said system; and (b) introducing to the system a refrigerant
composition of claim 8.
19. A method for modifying a refrigeration apparatus which
refrigeration apparatus comprises a refrigerant and a lubricant,
which refrigerant comprises a chlorofluorocarbon, a
hydrofluorocarbon, a hydrochlorofluorocarbon, a chlorofluorcarbon,
or combinations thereof, and the lubricant comprises a mineral oil,
alkybenezene, polyalphaolefin, polyol ester, polyakylene glycol,
polyvinyl ether, synthetic naphthalene, fluorolubricant or
combinations thereof, the method comprising removing or leaking at
least a portion of the refrigerant from the refrigeration apparatus
and leaving a residue comprising the lubricant, and adding to said
residue the azeotrope-like composition of claim 1.
20. A solvent comprising the azeotrope-like composition of claim 1.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a division of Ser. No. 12/542,185, filed
Aug. 17, 2009, which application claims the benefit of U.S.
Provisional patent application Ser. No. 61/089,986 filed Aug. 19,
2008.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present invention provides azeotrope-like compositions
of 1,1,1,2-tetrafluoropropene (HFO-1234yf) and
1,1,1,2-tetrafluoroethane (HFC-134a), and uses thereof, including
use in refrigerant compositions, refrigeration systems, blowing
agent compositions, and aerosol propellants.
Description of the Related Art
[0003] Fluorocarbon based fluids have found widespread use in
industry in a number of applications, including as refrigerants,
aerosol propellants, blowing agents, heat transfer media, and
gaseous dielectrics. Because of the suspected environmental
problems associated with the use of some of these fluids, including
the relatively high global warming potentials associated therewith,
it is desirable to use fluids having low or even zero ozone
depletion potential, such as hydrofluorocarbons ("HFCs"), and low
global warming potential.
[0004] Thus, the use of fluids that do not contain
chlorofluorocarbons ("CFCs") or hydrochlorofluorocarbons ("HCFCs")
is desirable. The use of alkenes is also desirable due to there
short atmospheric lifetime which results in a relatively low global
warming potential. Additionally, the use of single component fluids
or azeotropic mixtures, which do not fractionate on boiling and
evaporation, is desirable. However, the identification of new,
environmentally-safe, non-fractionating mixtures is complicated due
to the fact that azeotrope formation is not readily predictable.
The industry is continually seeking new fluorocarbon based mixtures
that offer alternatives, and are considered environmentally safer
substitutes for CFCs and HCFCs. Of particular interest are mixtures
containing hydrofluorocarbons, hydrofluorolefins ("HFOs") and other
fluorinated compounds, which have a zero ozone depletion potentials
and low global warming potential. Such mixtures are the subject of
this invention.
[0005] The present invention provides compositions that help to
satisfy the continuing need for alternatives to CFCs and HCFCs.
According to certain embodiments, the present invention provides
azeotrope-like compositions comprising of
1,1,1,2-tetrafluoropropene (HFO-1234yf) and
1,1,1,2-tetrafluoroethane (HFC-134a). The preferred compositions of
the invention tend to exhibit relatively low global warming
potentials ("GWPs"). Accordingly, such compositions can be used to
great advantage in a number of applications, including as
replacements for CFCs, HCFCs, and HFCs (such as HFC-134a) in
refrigerant, aerosol, blowing agents, and other applications. This
azeotrope-like composition can be used as a replacement in systems
already utilizing HFC-134a where a significant reduction in GWP is
desired. Additionally, it has been surprisingly found that
azeotrope-like compositions of HFO-1234yf and HFC-134a can be
formed. Accordingly, the present invention provides methods of
producing an azeotrope-like composition comprising combining
HFO-1234yf and HFC-134a in amounts effective to produce an
azeotrope-like composition. In addition, it has been found that the
azeotrope-like compositions of the present invention exhibit
properties that make that make them advantageous for use as, or in,
refrigerant, aerosol, and blowing agent compositions. Accordingly,
in yet other embodiments, the present invention provides
refrigerant compositions comprising an azeotrope-like composition
of HFO-1234yf and HFC-134a.
SUMMARY OF THE INVENTION
[0006] The invention provides an azeotrope-like composition
consisting essentially of effective amounts of
1,1,1,2-tetrafluoropropene and 1,1,1,2-tetrafluoroethane to form an
azeotrope-like composition.
[0007] The invention also provides a method of recharging a
refrigerant system that contains a refrigerant to be replaced and a
lubricant comprising the steps of: (a) removing the refrigerant to
be replaced from the refrigeration system while retaining a
substantial portion of the lubricant in said system; and (b)
introducing to the system a refrigerant composition comprising the
above azeotrope-like composition.
DETAILED DESCRIPTION OF THE INVENTION
[0008] Accordingly, the present invention provides azeotrope-like
compositions comprising 1,1,1,2-tetrafluoropropene (HFO-1234yf) and
1,1,1,2-tetrafluoroethane (HFC-134a), and uses thereof including
use in refrigerant compositions, refrigeration systems, blowing
agent compositions, and aerosol propellants.
[0009] As used herein, the term "azeotrope-like" is intended in its
broad sense to include both compositions that are strictly
azeotropic and compositions that behave like azeotropic mixtures.
From fundamental principles, the thermodynamic state of a fluid is
defined by pressure, temperature, liquid composition, and vapor
composition. An azeotropic mixture is a system of two or more
components in which the liquid composition and vapor composition
are equal at the stated pressure and temperature. In practice, this
means that the components of an azeotropic mixture are
constant-boiling and cannot be separated during a phase change. The
azeotrope-like compositions of the invention may include additional
components that do not form new azeotrope-like systems, or
additional components that are not in the first distillation cut.
The first distillation cut is the first cut taken after the
distillation column displays steady state operation under total
reflux conditions. One way to determine whether the addition of a
component forms a new azeotrope-like system so as to be outside of
this invention is to distill a sample of the composition with the
component under conditions that would be expected to separate a
non-azeotropic mixture into its separate components. If the mixture
containing the additional component is non-azeotrope-like, the
additional component will fractionate from the azeotrope-like
components. If the mixture is azeotrope-like, some finite amount of
a first distillation cut will be obtained that contains all of the
mixture components that is constant boiling or behaves as a single
substance. It follows from this that another characteristic of
azeotrope-like compositions is that there is a range of
compositions containing the same components in varying proportions
that are azeotrope-like or constant boiling. All such compositions
are intended to be covered by the terms "azeotrope-like" and
"constant boiling". As an example, it is well known that at
differing pressures, the composition of a given azeotrope will vary
at least slightly, as does the boiling point of the composition.
Thus, an azeotrope of A and B represents a unique type of
relationship, but with a variable composition depending on
temperature and/or pressure. It follows that, for azeotrope-like
compositions, there is a range of compositions containing the same
components in varying proportions that are azeotrope-like. All such
compositions are intended to be covered by the term azeotrope-like
as used herein. It is well-recognized in the art that it is not
possible to predict the formation of azeotropes. (See, for example,
U.S. Pat. No. 5,648,017 (column 3, lines 64-65) and U.S. Pat. No.
5,182,040 (column 3, lines 62-63), both of which are incorporated
herein by reference). It has been unexpectedly discovered that
HFO-1234yf and HFC-134a form azeotrope-like compositions.
[0010] According to certain preferred embodiments, the
azeotrope-like compositions of the present invention comprise, and
preferably consist essentially of, effective amounts of HFO-1234yf
and HFC-134a. The term "effective amounts" as used herein refers to
the amount of each component which upon combination with the other
component, results in the formation of an azeotrope-like
composition of the present invention. The azeotrope-like
compositions of the present invention can be produced by combining
effective amounts of HFO-1234yf and HFC-134a. Any of a wide variety
of methods known in the art for combining two or more components to
form a composition can be adapted for use in the present methods to
produce an azeotrope-like composition. For example, HFO-1234yf and
HFC-134a can be mixed, blended, or otherwise contacted by hand
and/or by machine, as part of a batch or continuous reaction and/or
process, or via combinations of two or more such steps. In light of
the disclosure herein, those of skill in the art will be readily
able to prepare azeotrope-like compositions according to the
present invention without undue experimentation.
[0011] The HFO-1234yf and HFC-134a are present in amounts effective
to produce an azeotrope-like composition. In one embodiment the
HFO-1234yf is present in the azeotrope-like composition in an
amount of from about 40 to less than 100 weight percent, preferably
from about 50 to less than 90 weight percent, and more preferably
from about 55 to about 80 weight percent. In one embodiment the
HFC-134a, is present in the azeotrope-like composition in an amount
of from greater than zero to about 60 weight percent, preferably
from about 10 to about 50 weight percent, and more preferably from
about 20 to about 45 weight percent. Usually the inventive
azeotrope-like compositions have a boiling point of from about
-30.0.degree. C. to about -29.0.degree. C. at a pressure of about
14.3 psia.
[0012] The present compositions have utility in a wide range of
applications. For example, one embodiment of the present invention
relates to blowing agent, as part of a sprayable composition such
as an aerosol composition, as a cleaning composition, and
refrigerant compositions, all comprising the present azeotrope-like
compositions.
[0013] One embodiment of the present invention relates to a blowing
agent comprising one or more azeotrope-like compositions. One
embodiment of the present invention relates to methods of forming
thermoset foams, and preferably polyurethane and polyisocyanurate
foams. The methods generally comprise providing a blowing agent
composition of the present inventions, adding (directly or
indirectly) the blowing agent composition to a foamable
composition, and reacting the foamable composition under the
conditions effective to form a foam or cellular structure, as is
well known in the art. These foams may be open cell or closed cell.
Any of the methods well known in the art, such as those described
in "Polyurethanes Chemistry and Technology," Volumes I and II,
Saunders and Frisch, 1962, John Wiley and Sons, New York, N.Y.,
which is incorporated herein by reference, may be used or adapted
for use in accordance with the foam embodiments of the present
invention. In general, such preferred methods comprise preparing
polyurethane or polyisocyanurate foams by combining an isocyanate,
a polyol or mixture of polyols, a blowing agent or mixture of
blowing agents comprising one or more of the present compositions,
and other materials such as catalysts, surfactants, and optionally,
flame retardants, colorants, or other additives.
[0014] It is convenient in many applications to provide the
components for polyurethane or polyisocyanurate foams in
pre-blended formulations. Most typically, the foam formulation is
pre-blended into two components. The isocyanate and optionally
certain surfactants and blowing agents comprise the first
component, commonly referred to as the "A" component. The polyol or
polyol mixture, surfactant including silicone surfactants,
catalysts including amine catalysts, blowing agents, flame
retardant, and other isocyanate reactive components comprise the
second component, commonly referred to as the "B" component. The
blowing agent comprises the azeotrope-like composition of this
invention and optionally a hydrocarbon, halogenated hydrocarbon,
CO.sub.2 generating material, or combinations thereof. Preferably
the halogenated hydrocarbon comprises a chlorofluorocarbon,
hydrochlorofluorocarbon, hydrofluorocarbon, or combinations
thereof. The blowing agent component is usually present in the
polyol premix composition in an amount of from about 1 wt. % to
about 30 wt. %, by weight of the polyol premix composition. The
polyol component, can be any polyol which reacts in a known fashion
with an isocyanate in preparing a polyurethane or polyisocyanurate
foam. Useful polyols comprise one or more of a sucrose containing
polyol; phenol, a phenol formaldehyde containing polyol; a glucose
containing polyol; a sorbitol containing polyol; a methylglucoside
containing polyol; an aromatic polyester polyol; glycerol; ethylene
glycol; diethylene glycol; propylene glycol; graft copolymers of
polyether polyols with a vinyl polymer; a copolymer of a polyether
polyol with a polyurea; or combinations thereof. The polyol
component is usually present in the polyol premix composition in an
amount of from about 60 wt. % to about 95 wt. %, by weight of the
polyol premix composition. The polyol premix composition next
contains a surfactant component which silicone surfactant and
optionally an additional non-silicone surfactant. The surfactant is
usually present in the polyol premix composition in an mount of
from about 0.5 wt. % to about 5.0 wt. % by weight of the polyol
premix composition. The polyol premix composition next contains a
catalyst which is preferably an amine. Tertiary amines are
preferred. Preferred amines include: N,N-dimethylcyclohexylamine,
dimethlyethanolamine,
N,N,N',N',N'',N''-pentamethyldiethylenetriamine,
1,4-diaza-bicyclo[2.2.2]octane (DABCO), and triethylamine. The
catalyst is usually present in the polyol premix composition in an
amount of from about 0.1 wt. % to about 3.5 wt. % by weight of the
polyol premix composition.
[0015] A foamable composition suitable for forming a polyurethane
or polyisocyanurate foam may be formed by reacting an organic
polyisocyanate and the polyol premix composition described above.
Any organic polyisocyanate can be employed in polyurethane or
polyisocyanurate foam synthesis inclusive of aliphatic and aromatic
polyisocyanates. Suitable organic polyisocyanates include
aliphatic, cycloaliphatic, araliphatic, aromatic, and heterocyclic
isocyanates which are well known in the field of polyurethane
chemistry. These are described in, for example, U.S. Pat. Nos.
4,868,224; 3,401,190; 3,454,606; 3,277,138; 3,492,330; 3,001,973;
3,394,164; 3,124,605; and 3,201,372. Preferred as a class are the
aromatic polyisocyanates. Representative organic polyisocyanates
correspond to the formula:
R(NCO)z
[0016] wherein R is a polyvalent organic radical which is either
aliphatic, aralkyl, aromatic or mixtures thereof, and z is an
integer which corresponds to the valence of R and is at least
two.
[0017] Accordingly, polyurethane or polyisocyanurate foams are
readily prepared by bringing together the A and B side components
either by hand mix for small preparations and, preferably, machine
mix techniques to form blocks, slabs, laminates, pour-in-place
panels and other items, spray applied foams, froths, and the like.
Optionally, other ingredients such as fire retardants, colorants,
auxiliary blowing agents, and even other polyols can be added as a
third stream to the mix head or reaction site. Most preferably,
however, they are all incorporated into one B-component as
described above. Conventional flame retardants can also be
incorporated, preferably in amount of not more than about 20
percent by weight of the reactants.
[0018] The present methods and systems also include forming a one
component foam, preferably polyurethane foam, containing a blowing
agent in accordance with the present invention. In certain
preferably embodiments, a portion of the blowing agent is contained
in the foam forming agent, preferably by being dissolved in a foam
forming agent which is liquid at the pressure within the container,
a second portion of the blowing agent is present as a separate gas
phase. In such systems, the contained/dissolved blowing agent
performs, in large part, to cause the expansion of the foam, and
the separate gas phase operates to impart propulsive force to the
foam forming agent. Such one component systems are typically and
preferably packaged in a container, such as an aerosol type can,
and the blowing agent of the present invention thus preferably
provides for expansion of the foam and/or the energy to transport
the foam/foamable material from the package, and preferably both.
In certain embodiments, such systems and methods comprise charging
the package with a fully formulated system (preferably
isocyanate/polyol system) and incorporating a gaseous blowing agent
in accordance with the present invention into the package,
preferably an aerosol type can.
[0019] In addition to the previously described ingredients, other
ingredients such as, dyes, fillers, pigments and the like can be
included in the preparation of the foams. Dispersing agents and
cell stabilizers can be incorporated into the present blends.
Conventional fillers for use herein include, for example, aluminum
silicate, calcium silicate, magnesium silicate, calcium carbonate,
barium sulfate, calcium sulfate, glass fibers, carbon black and
silica. The filler, if used, is normally present in an amount by
weight ranging from about 5 parts to 100 parts per 100 parts of
polyol. A pigment which can be used herein can be any conventional
pigment such as titanium dioxide, zinc oxide, iron oxide, antimony
oxide, chrome green, chrome yellow, iron blue siennas, molybdate
oranges and organic pigments such as para reds, benzidine yellow,
toluidine red, toners and phthalocyanines. The polyurethane or
polyisocyanurate foams produced can vary in density from about 0.5
pounds per cubic foot to about 60 pounds per cubic foot, preferably
from about 1.0 to 20.0 pounds per cubic foot, and most preferably
from about 1.5 to 6.0 pounds per cubic foot. The density obtained
is a function of how much of the blowing agent or blowing agent
mixture disclosed in this invention plus the amount of auxiliary
blowing agent, such as water or other co-blowing agents is present
in the A and/or B components, or alternatively added at the time
the foam is prepared. These foams can be rigid, flexible, or
semi-rigid foams, and can have a closed cell structure, an open
cell structure or a mixture of open and closed cells. These foams
are used in a variety of well known applications, including but not
limited to thermal insulation, cushioning, flotation, packaging,
adhesives, void filling, crafts and decorative, and shock
absorption.
[0020] It is also possible to produce thermoplastic foams using the
compositions of the invention. For example, conventional
polystyrene and polyethylene formulations may be combined with the
compositions in a conventional manner to produce rigid foams
Examples of thermoplastic foam components include polyolefins, such
as for example polystyrene. Other examples of thermoplastic resins
include polyethylene, ethylene copolymers, polypropylene, and
polyethyleneterephthalate. In certain embodiments, the
thermoplastic foamable composition is an extrudable composition. It
is also generally recognized that the thermoplastic foamable
composition may include adjuvants such as nucleating agents, flame
or fire retardant materials, cell modifiers, cell pressure
modifiers, and the like.
[0021] With respect to thermoplastic foams, the preferred methods
generally comprise introducing a blowing agent in accordance with
the present invention into a thermoplastic material, and then
subjecting the thermoplastic material to conditions effective to
cause foaming. For example, the step of introducing the blowing
agent into the thermoplastic material may comprise introducing the
blowing agent into a screw extruder containing a thermoplastic
polymer, and the step of causing foam may comprise lowering the
pressure on the thermoplastic material and thereby causing
expansion of the blowing agent and contributing to the foaming of
the material. Suitable thermoplastic polymers non-exclusively
include polystyrene, polyethylene, polypropylene, polyethylene
terephthalate, and combinations of these. It will be generally
appreciated by those skilled in the art, especially in view of the
disclosure herein, that the order and manner in which the blowing
agent of the present invention is formed and/or added to the
foamable composition does not generally affect the operability of
the present invention thermoset or thermoplastic foams. It is
contemplated also that in certain embodiments it may be desirable
to utilize the present compositions when in the supercritical or
near supercritical state as a blowing agent.
[0022] The azeotrope-like compositions of this invention may also
be used as refrigerant compositions. The refrigerant compositions
of the present invention may be used in any of a wide variety of
refrigeration systems including air-conditioning, refrigeration,
heat-pump systems, and the like. In certain preferred embodiments,
the compositions of the present invention are used in refrigeration
systems originally designed for use with an HFC refrigerant, such
as, for example, HFC-134a. The preferred compositions of the
present invention tend to exhibit many of the desirable
characteristics of HFC-134a and other HFC-refrigerants, including
non-flammability or low flammability, and a GWP that is as low, or
lower than that of conventional HFC-refrigerants. In addition, the
relatively constant boiling nature of the compositions of the
present invention makes them even more desirable than certain
conventional HFCs for use as refrigerants in many applications.
[0023] In certain embodiments, the compositions of the present
invention may be used to retrofit refrigeration systems containing
a refrigerant which comprises a chlorofluorocarbon, a
hydrofluorocarbon, a hydrochlorofluorocarbon, a chlorofluorcarbon,
or combinations thereof and lubricants conventionally used
therewith. Such as a mineral oil, alkybenezene (AB),
polyalphaolefin (PAO), polyol ester (POE), polyakylene glycol
(PAG), polyvinyl ether (PVE), synthetic naphthalene,
fluorolubricant or combinations thereof. The method comprises
removing or leaking at least a portion of the refrigerant from the
refrigeration apparatus and leaving a residue comprising the
lubricant, and adding to said residue the inventive azeotrope-like
composition. Preferred refrigeration compositions of the present
invention may be used in refrigeration systems containing a
lubricant used conventionally with CFC HCFC, and/or
CFC-refrigerants, such as mineral oils, silicone oils, and the
like, or may be used with other lubricants traditionally used with
such refrigerants. Preferably, the present methods involve
recharging a refrigerant system that contains a refrigerant to be
replaced and a lubricant comprising the steps of (a) removing the
refrigerant to be replaced from the refrigeration system while
retaining a substantial portion of the lubricant in said system;
and (b) introducing to the system a composition of the present
invention. As used herein, the term "substantial portion" refers
generally to a quantity of lubricant which is at least about 50%
(by weight) of the quantity of lubricant contained in the
refrigeration system prior to removal of the refrigerant.
Preferably, the substantial portion of lubricant in the system
according to the present invention is a quantity of at least about
60% of the lubricant contained originally in the refrigeration
system, and more preferably a quantity of at least about 70%. As
used herein the term "refrigeration system" refers generally to any
system or apparatus, or any part or portion of such a system or
apparatus, which employs a refrigerant to provide cooling to one
space thereby heating another. Such refrigeration systems include,
for example, air conditioners including automotive air
conditioning, electric refrigerators, chillers, transport
refrigeration systems, commercial refrigeration systems and the
like. Refrigeration systems may also include heat pump systems
where as the desired benefit is the heating provided by condensing
the refrigerant stream and the cooling portion or evaporator
extracts heat from the surroundings or other energy streams for use
in such heating.
[0024] Any of a wide range of known methods can be used to remove
refrigerants to be replaced from a refrigeration system while
removing less than a major portion of the lubricant contained in
the system. For example, because refrigerants are quite volatile
relative to traditional hydrocarbon-based lubricants, such as
mineral oil, alkybenezene (AB), polyalphaolefins (PAO), polyol
esters (POE), polyakylene glycols (PAG), fluorolubricants and the
like (the boiling points of refrigerants are generally less than
10.degree. C. whereas the boiling points of lubricants are
generally more than 200.degree. C.). In embodiments wherein the
lubricant is a hydrocarbon-based lubricant, the removal step may
readily be performed by pumping refrigerants in the gaseous state
out of a refrigeration system containing liquid state lubricants.
Such removal can be achieved in any of a number of ways known in
the art, including, the use of a refrigerant recovery system, such
as the recovery system manufactured by Robinair of Ohio.
Alternatively, a cooled, evacuated refrigerant container can be
attached to the low pressure side of a refrigeration system such
that the gaseous refrigerant is drawn into the evacuated container
and removed. Moreover, a compressor may be attached to a
refrigeration system to pump the refrigerant from the system to an
evacuated container. In light of the above disclosure, those of
ordinary skill in the art will be readily able to remove the system
refrigerant charge without removing the majority of the lubricant
and charging with the disclosed azeotrope-like blend of HFC-134a
and HFO-1234yf according to the present invention.
[0025] Another way for which refrigerant may be removed from the
system is in the case of leaks, hose permeation or system failure
in which an operator does not play an active part in the
refrigerant removal, but rather the nature of the system seal,
materials of construction, or operating conditions cause
refrigerant removal. In this case if an operator "tops off" a
system where as the full refrigerant charge has not yet been
removed. This is common practice in automotive air conditioning
systems where the user experiences decreased performance and a
service shops or the home user themselves recharge the system,
pulling either HFO-1234yf into a system originally designed
HFC-134a or pulling HFC-134a into a system originally designed for
HFO-1234yf. This would constitute a partial charge, but would allow
for azeotrope-like blend of HFC-134a and HFO-1234yf according to
the present invention. Any of a wide range of methods for
introducing the present refrigerant compositions to a refrigeration
system can be used in the present invention. For example, one
method comprises attaching a refrigerant container to the
low-pressure side of a refrigeration system and turning on the
refrigeration system compressor to pull the refrigerant into the
system. In such embodiments, the refrigerant container may be
placed on a scale such that the amount of refrigerant composition
entering the system can be monitored. When a desired amount of
refrigerant composition has been introduced into the system,
charging is stopped. Alternatively, a wide range of charging tools,
known to those of skill in the art, is commercially available.
Accordingly, in light of the above disclosure, those of skill in
the art will be readily able to introduce the refrigerant
compositions of the present invention into refrigeration systems
according to the present invention without undue
experimentation.
[0026] According to certain other embodiments, the present
invention provides refrigeration systems comprising a refrigerant
of the present invention and methods of producing heating or
cooling by condensing and/or evaporating a composition of the
present invention. In certain preferred embodiments, the methods
for cooling an article according to the present invention comprise
condensing a refrigerant composition comprising an azeotrope-like
composition of the present invention and thereafter evaporating
said refrigerant composition in the vicinity of the article to be
cooled. Certain preferred methods for heating an article comprise
condensing a refrigerant composition comprising an azeotrope-like
composition of the present invention in the vicinity of the article
to be heated and thereafter evaporating said refrigerant
composition. In light of the disclosure herein, those of skill in
the art will be readily able to heat and cool articles according to
the present inventions without undue experimentation.
[0027] In another embodiment, the azeotrope-like compositions of
this invention may be used as propellants in sprayable
compositions, either alone or in combination with known
propellants. The propellant composition comprises, more preferably
consists essentially of, and, even more preferably, consists of the
azeotrope-like compositions of the invention. The active ingredient
to be sprayed together with inert ingredients, solvents, and other
materials may also be present in the sprayable mixture. Preferably,
the sprayable composition is an aerosol. Suitable active materials
to be sprayed include, without limitation, cosmetic materials such
as a deodorant, a perfume, and a hair spray; cleansers, a wax, a
defluxing agent, a polishing agent a room freshener, an
insecticide, a cooking oil, as well as a drug or other biologically
active material including medicinal materials such as anti-asthma
and anti-halitosis medications, or combinations of any of the
foregoing. Other uses of the present azeotrope-like compositions
include use as solvents, cleaning agents, and the like. Those
skilled in the art will be readily able to adapt the present
compositions for use in such applications without undue
experimentation.
EXAMPLES
[0028] The following non-limiting examples serve to illustrate the
invention.
Example 1
[0029] An ebulliometer consisting of vacuum jacketed tube with a
condenser on top which is further equipped with a Quartz
Thermometer is used. About 17.41 g of HFO-1234yf is charged to the
ebulliometer and then HFC-134a is added in small, measured
increments. Temperature depression is observed when HFC-134a is
added to HFO-1234yf, indicating a binary minimum boiling azeotrope
is formed. From greater than about 0 to about 60 weight percent
HFC-134a, the boiling point of the composition stays below or
around the boiling point of HFO-1234yf. The normal boiling
temperature of HFC-134a is about -26.3.degree. C. The binary
mixtures shown in Table 1 show the boiling point of the
compositions did not go above the boiling point of HFO-1234yf. The
compositions exhibit azeotrope and/or azeotrope-like properties
over this range.
TABLE-US-00001 TABLE 1 HFO-1234yf/HFC-134a Compositions at 14.3
psia T (.degree. C.) Wt. % HFO-1234yf Wt. % HFC-134a -28.97 100.0
0.00 -29.13 97.81 2.19 -29.63 89.83 10.17 -29.66 86.27 13.73 -29.86
75.89 24.11 -29.91 71.29 28.71 -29.92 65.16 34.84 -29.91 60.68
39.32 -29.81 56.27 43.73 -29.67 52.71 47.29 -29.38 47.10 52.90
-29.16 43.38 56.62
Example 2
[0030] An azeotrope-like composition (50/50 by mass) of HFO-1234yf
and HFC-134a was charged into an instrumented automotive air
condition system and tested under the conditions typical for normal
operation. The conditions are specified in a Society of Automotive
Engineers (SAE) Standard J2765 as conditions experienced during
operation of a motor vehicle. The system was evaluated at
conditions representing full load cooling for ambient temperatures
of 35, 45 and 50.degree. C. as to exclude compressor cycling and
system control influence of the results. Table 2 illustrates
results from such testing. Lower discharge temperatures and higher
suction pressures make this azeotrope-like blend attractive in
refrigeration and heat pump operation. The lower discharge
temperature adds robustness in thermal stability of system
lubricants, materials and the refrigerant itself. The higher
suction pressure competes against the higher discharge pressure of
the mixtures; however, this allows for further heat exchanger
optimization to achieve energy usage savings.
TABLE-US-00002 TABLE 2 Results of MAC testing with azeotrope-like
compositions of HFO-1234yf and HFC-134a Condition* I45 M45 H45 I50
I35 M35 H35 Discharge Blend 79.8 90.47 103.4 88.4 74.6 87.9 101.1
Temperature, HFC-134a Alone 89.7 105.7 121.0 97.2 82.6 99.3 113.5
.degree. C. HFO-1234yf 80.2 93.0 105.4 87.6 73.8 88.4 101.5 Alone
Discharge Blend 1.94 2.02 1.99 2.21 1.65 1.73 1.71 Pressure,
HFC-134a Alone 1.91 1.92 1.90 2.20 1.60 1.63 1.63 MPa HFO-1234yf
1.82 1.87 1.86 2.06 1.53 1.59 1.89 Alone Evaporation Blend 9.4 2.4
-0.2 13.1 10.5 2.6 -0.1 Temperature, HFC-134a Alone 9.3 2.5 0.9
12.9 10.7 3.8 2.0 .degree. C. HFO-1234yf 10.0 3.9 2.2 13.0 10.8 4.5
3.0 Alone Suction Blend 432 316 275 487 446 314 272 Pressure,
HFC-134a Alone 383 267 235 434 403 277 238 kPa HFO-1234yf 404 294
258 446 411 293 253 Alone System Blend 4.13 6.47 8.16 4.40 5.10
7.51 9.55 Cooling HFC-134a Alone 4.26 6.67 8.22 4.51 5.12 7.97 9.71
Capacity, HFO-1234yf 4.26 6.59 8.25 4.42 4.97 7.68 9.52 kW Alone
System Blend 2.1 1.3 1.1 2.0 2.9 1.7 1.4 Efficiency, HFC-134a Alone
2.3 1.5 1.1 2.2 3.1 1.8 1.4 COP HFO-1234yf 2.2 1.4 1.1 2.1 3.0 1.7
1.3 (kW/kW) Alone *Condition are specified by SAE Standard J2765
wherein: I35 = automobile idling at 35.degree. C. ambient
temperature. I45 = automobile idling at 45.degree. C. ambient
temperature. I50 = automobile idling at 50.degree. C. ambient
temperature. M35 = automobile at medium speeds of 35-45 mph at
35.degree. C. ambient temperature. M45 = automobile at medium
speeds of 35-45 mph at 45.degree. C. ambient temperature. H35 =
automobile at high speeds of 65-80 mph at 35.degree. C. ambient
temperature. H45 = automobile at high speeds of 65-80 mph at
45.degree. C. ambient temperature. The compositions are HFC-134a
Alone, HFO-1234yf Alone and 50/50 by mass blends of HFC-134a and
HFO-1234yf.
[0031] While the present invention has been particularly shown and
described with reference to preferred embodiments, it will be
readily appreciated by those of ordinary skill in the art that
various changes and modifications may be made without departing
from the spirit and scope of the invention. It is intended that the
claims be interpreted to cover the disclosed embodiment, those
alternatives which have been discussed above and all equivalents
thereto.
* * * * *