The present invention provides a composition comprising tetrafluoroethane and one or more components selected from R152a and R125 for use as aerosols, as blowing agents, in cleaning or deposition of certain types of lubricants, as a dust off, freeze spray, or tire inflator.

BACKGROUND OF THE INVENTION
Fluorocarbon based fluids have found widespread use in industry for refrigeration, air conditioning, heat pump applications, foam blowing agents, aerosol, and solvents.
Currently, environmentally acceptable fluorocarbon-based compounds are of particular interest because chlorofluorocarbons cause environmental problems like depletion of the earth's protective ozone layer. It has been found that hydrofluorocarbons like 1.1.1.2-tetrafluoroethane (HFC-134a), pentafluoroethane (HFC-125) and 1.1-difluoroethane (HFC-152a) will not adversely affect atmospheric chemistry because their contribution to stratospheric ozone depletion is negligible.
E.P. Pub. No. 0505436A1 provides an azeotrope-like compositions comprising 1,1,1,2-tetrafluoroethane and 1,1-difluoroethane which have a vapor pressure of about 76 psia ± 5 psia at 20°C.
U.S. Pat. No. 5725791 provides an azeotropic composition consisting essentially of about 80-99 weight percent 1,1,2,2-tetrafluoroethane and about 1-20 weight percent 1,1-difluoroethane, wherein the dew point and the bubble point are both about -19.6° C. at 14.7 psia.
The present invention provides a composition comprising tetrafluoroethane and one or more components selected from R152a and R125.
OBJECT OF THE INVENTION
The main object of the present invention is to provide a composition comprising tetrafluoroethane and one or more component selected from R152a and R125 for use as blowing agents, solvents, aerosols for cleaning or deposition of certain types of lubricants, as a dust off, freeze spray or tire inflator.

SUMMARY OF THE INVENTION
The present invention provides a composition comprising of 10% by weight to 90% by weight of R134a and 10% by weight to 90% by weight of R152a.
In an aspect, the present invention provides a composition comprising of 10% by weight to 40% by weight of R134a; and 60% by weight to 90% by weight of R152a.
In another aspect, the present invention provides a composition comprising 45% by weight to 80% by weight of R134a; 15% by weight to 45% by weight of R152a; and 5% by weight to 15% by weight of R125.

DETAILED DESCRIPTION OF THE INVENTION
In an embodiment, the present invention provides a composition comprising of 10% by weight to 90% by weight of R134a and 10% by weight to 90% by weight of R152a.
In another embodiment, the present invention provides a composition comprising of 10% by weight to 80% by weight of R134a and 10% by weight to 90% by weight of R152a.
In another embodiment, the present invention provides a composition comprising: 10% by weight to 40% by weight of R134a; and 60% by weight to 90% by weight of R152a.
In another embodiment, the present invention provides a composition comprising: 40% by weight to 90% by weight of R134a; and 10% by weight to 60% by weight of R152a.
In another embodiment, the present invention provides a composition comprising: 50% by weight to 80% by weight of R134a; and 20% by weight to 50% by weight of R152a.
In another embodiment, the present invention provides a composition comprising: 60% by weight to 70% by weight of R134a; and 30% by weight to 40% by weight of R152a.
In an embodiment, the present invention provides composition comprising: 15% by weight to 35% by weight of R134a; and 65% by weight to 80% by weight of R152a.
In another embodiment, the present invention provides an azeotropic composition comprising: 25% by weight to 35% by weight of R134a; and 65% by weight to 75% by weight of R152a, wherein the composition has a boiling point in range of -220C to -260C at atmospheric pressure.
In another embodiment, the present invention provides an azeotropic composition comprising: 28% by weight to 32% by weight of R134a; and 68% by weight to 72% by weight of R152a, wherein the composition has a boiling point in range of -230C to -250C at atmospheric pressure.
In another embodiment, the present invention provides an azeotropic composition 1 comprising: 30% by weight of R134a; and 70% by weight of R152a, wherein the composition has a boiling point of -240C at atmospheric pressure.
In another embodiment, the present invention provides an azeotropic composition comprising: 18% by weight to 22% by weight of R134a; and 78% by weight to 82% by weight of R152a, wherein the composition has a boiling point in range of -230C to -250C at atmospheric pressure.
In another embodiment of first aspect, the present invention provides an azeotropic composition 2 comprising: 20% by weight of R134a; and 80% by weight of R152a, wherein the composition has a boiling point of -240C at atmospheric pressure.
In another embodiment, the present invention provides an azeotropic composition comprising: 10% by weight to 12% by weight of R134a; and 88% by weight to 90% by weight of R152a, wherein the composition has a boiling point in range of -230C to -250C at atmospheric pressure.
In another embodiment, the present invention provides an azeotropic composition 3 comprising: 10% by weight of R134a; and 90% by weight of R152a, wherein the composition has a boiling point of -24.50C at atmospheric pressure.
In another embodiment, the present invention provides an azeotropic composition comprising: 38% by weight to 42% by weight of R134a; and 58% by weight 62% by weight of R152a, wherein the composition has a boiling point in range of -240C to -260C at atmospheric pressure.
In another embodiment, the present invention provides an azeotropic composition 4 comprising: 40% by weight of R134a; and 60% by weight of R152a, wherein the composition has a boiling point of -250C at atmospheric pressure.
In another embodiment, the present invention provides a composition comprising of 10% by weight to 90% by weight of R134a and 10% by weight to 90% by weight of R152a, wherein the composition further comprises of 5% by weight to 15% by weight of R125.
In another embodiment, the present invention provides a composition comprising of 20% by weight to 80% by weight of R134a and 10% by weight to 70% by weight of R152a, wherein the composition further comprises of 5% by weight to 15% by weight of R125.
In another embodiment, the present invention provides a composition comprising of 30% by weight to 70% by weight of R134a and 10% by weight to 60% by weight of R152a, wherein the composition further comprises of 5% by weight to 15% by weight of R125.
In another embodiment, the present invention provides a composition comprising of 40% by weight to 60% by weight of R134a and 10% by weight to 50% by weight of R152a, wherein the composition further comprises of 5% by weight to 15% by weight of R125.
In another embodiment, the present invention provides a composition comprising: 45% by weight to 80% by weight of R134a; 15% by weight to 45% by weight of R152a; and 5% by weight to 15% by weight of R125.
In another embodiment, the present invention provides a composition comprising: 55% by weight to 80% by weight of R134a; 15% by weight to 35% by weight of R152a; and 5% by weight to 15% by weight of R125.
In another embodiment, the present invention provides a near azeotropic composition comprising: 65% by weight to 75% by weight of R134a; 15% by weight to 25% by weight of R152a; and 5% by weight to 15% by weight of R125, wherein the composition has a boiling point in range of -240C to -300C at atmospheric pressure.
In another embodiment, the present invention provides a near azeotropic composition comprising: 68% by weight to 72% by weight of R134a; 18% by weight to 22% by weight of R152a; and 8% by weight to 12% by weight of R125, wherein the composition has a boiling point in range of -260C to -300C at atmospheric pressure.
In another embodiment, the present invention provides a near azeotropic composition 5 comprising: 70% by weight of R134a; 20% by weight of R152a; and 10% by weight of R125, wherein the composition has a boiling point of -280C at atmospheric pressure.
In another embodiment, the present invention provides a near azeotropic composition comprising: 58% by weight to 62% by weight of R134a; 28% by weight to 32% by weight of R152a; and 8% by weight to 12% by weight of R125, wherein the composition has a boiling point in range of -250C to -300C at atmospheric pressure.
In an embodiment, the present invention provides a near azeotropic composition 6 comprising: 60% by weight of R134a; 30% by weight of R152a; and 10% by weight of R125, wherein the composition has a boiling point of -270C at atmospheric pressure.
Non-azeotropic composition is a mixture of two or more substances that behaves as a simple mixture rather than a single substance.
As used herein, the term “near azeotrope” 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 state 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 “near azeotrope” compositions behave like azeotropic mixtures, that is, they are constant boiling or essentially constant boiling. In other words, for near azeotrope- compositions, the composition of the vapor formed during boiling or evaporation is identical, or substantially identical, to the original liquid composition. Thus, with boiling or evaporation, the liquid composition changes, if at all, only to a minimal or negligible extent. This is to be contrasted with non-azeotrope-like compositions in which, during boiling or evaporation, the liquid composition changes to a substantial degree. All near azeotrope compositions of the invention within the indicated ranges as well as certain compositions outside these ranges are azeotrope-like.
In another embodiment, the present invention provides azeotropic or near azeotropic compositions comprising 10% by weight to 90% by weight of R134a and 10% by weight to 90% by weight of R152a.
In another embodiment, the present invention provides azeotropic or near azeotropic compositions comprising of 10% by weight to 90% by weight of R134a; 10% by weight to 90% by weight of R152a and 5% by weight to 15% by weight of R125.
In another embodiment, the compositions of the present invention are used in cooling and heating applications, as blowing agent, cleaning solvent, aerosols, refrigerants and heat transfer agents.
In an embodiment, the compositions of the present invention are used in industry for solvent cleaning and solvents in aerosols for the degreasing and otherwise cleaning of solid surfaces, especially intricate parts and difficult to remove soils.
In another embodiment, the compositions of the present inventions are used in aerosol solvent applications of cleaning or deposition of certain types of lubricants, as a dust off, freeze spray or tire inflator.
In another embodiment, the compositions of the present invention are used as industrial aerosol to be employed for anti-rust oil, carburettor cleaning oil, chain lubricant, silicon plastic moulding, zinc coating and solvents.
In another embodiment, the compositions of the present invention are useful as paints, perfumes, etc.
In another embodiment, the compositions of the present invention are useful in domestic products like room fresheners, insecticides sprays and air conditioner coil cleaners etc.
In another embodiment, the composition of the present invention finds widespread use in industry for solvent cleaning and solvents in aerosols for the degreasing and otherwise cleaning of solid surfaces, especially intricate parts and difficult to remove soils.
In another embodiment, the compositions of the present invention are useful as aerosol solvent applications for cleaning or deposition of certain types of lubricants, as a dust off, freeze spray or tire inflator. The compositions of the present invention act to propel and convert user product such as paints, lubricants, fire extinguisher and electrical & instrumentation panel cleaning agents into aerosols.
In another embodiment, the compositions of the present invention are non-inflammable and non-toxic.
In another embodiment, the compositions of the present invention provide a zero ODP substitute to HCFC-141b as solvents and cleaning agents.
In another embodiment, the compositions of the present invention provide a zero ODP substitute to HCFC-141b as aerosols for degreasing or cleaning of solid surfaces, for deposition of certain types of lubricants, and to propel and convert user product such as paints, lubricants.
In another embodiment, the present invention provides aerosol compositions used for degreasing or cleaning of solid surfaces, and for deposition of user products such as lubricants, paints, varnishes or the like.
In another embodiment, the present invention provides compositions having zero ODP to provide environment friendly substitute for HCFC-141b.
In another embodiment, the compositions of the present invention have thermal conductivity comparable to HCFC-141b.
In another embodiment, the compositions of the present inventions may additionally contain a chlorinated hydrocarbon such as dichloromethane.
The various components as used in the present invention are described in the table below.
Table-1
Components Chemical name Chemical formula
R125 Pentafluoroethane CF3CHF2
R134a 1,1,1,2-tetrafluoroethane CH2FCF3
R152a 1,1-difluoroethane CHF2CH3

The various properties of the compositions of present invention are tabulated below.
Table-2
Phase Parameters Composition
1 2 3
Vapor Phase Temperature
(°C) 25 25 25
Liquid Phase Pressure
(bar) 6.0174 5.9919 5.9747
Vapor Phase Pressure
(bar) 6.0144 5.9907 5.9744
Liquid Phase Density
(kg/m3) 970.82 945.62 921.88
Vapor Phase Density
(kg/m3) 20.918 20.015 19.203
Liquid Phase Volume
(m3/kg) 0.00103 0.001058 0.001085
Vapor Phase Volume
(m3/kg) 0.047806 0.049962 0.052075
Liquid Phase Int. Energy
(kJ/kg) 240.81 241.6 242.35
Vapor Phase Int. Energy
(kJ/kg) 462.91 472.33 481.62
Liquid Phase Enthalpy
(kJ/kg) 241.43 242.23 243
Vapor Phase Enthalpy
(kJ/kg) 491.67 502.26 512.73
Liquid Phase Entropy
(kJ/kg-K) 1.1439 1.1467 1.1493
Vapor Phase Entropy
(kJ/kg-K) 1.9832 2.0188 2.054
Liquid Phase Cv
(kJ/kg-K) 1.0871 1.1052 1.1221
Vapor Phase Cv
(kJ/kg-K) 0.9521 0.96542 0.97823
Liquid Phase Cp
(kJ/kg-K) 1.702 1.7358 1.7685
Vapor Phase Cp
(kJ/kg-K) 1.1977 1.217 1.2356
Liquid Cp/Cv
1.5656 1.5705 1.576
Phase Vapor Phase Cp/Cv
1.2579 1.2606 1.2631
Liquid Phase Molar Mass
73.865 71.063 68.465
Vapor Phase Molar Mass
73.865 71.063 68.465
Liquid Phase Thermal Conductivity
(mW/m-K) 93.569 95.118 96.619
Vapor Phase Thermal Conductivity
(mW/m-K) 14.684 14.75 14.807
Liquid Phase Viscosity
(uPa-s) 168.42 166.35 164.56
Vapor Phase Viscosity
(uPa-s) 10.685 10.493 10.296
ODP 0 0 0

Table-3
Phase Parameters Compositions
4 5 6
Vapor Phase Temperature
(°C) 25
25 25
Liquid Phase Pressure
(bar) 6.0532
6.922 6.7943
Vapor Phase Pressure
(bar) 6.0473
6.619 6.4976
Liquid Phase Density
(kg/m3) 997.66
1128.4 1093.1
Vapor Phase Density
(kg/m3) 21.929
29.42 27.449
Liquid Phase Volume
(m3/kg) 0.001002
0.000886 0.00091487
Vapor Phase Volume
(m3/kg) 0.045602
0.03399 0.036431
Liquid Phase Int. Energy
(kJ/kg) 239.99
228.52 236.89
Vapor Phase Int. Energy
(kJ/kg) 453.35
404.46 417.35
Liquid Phase Enthalpy
(kJ/kg) 240.59
229.04 237.51
Vapor Phase Enthalpy
(kJ/kg) 480.93
426.97 441.02
Liquid Phase Entropy
(kJ/kg-K) 1.141
1.1017 1.1302
Vapor Phase Entropy
(kJ/kg-K) 1.9471
1.7785 1.8143
Liquid Phase Cv
(kJ/kg-K) 1.0676
0.95737 0.9893
Vapor Phase Cv
(kJ/kg-K) 0.93819
0.85215 0.88502
Liquid Phase Cp
(kJ/kg-K) 1.667
1.4834 1.5433
Vapor Phase Cp
(kJ/kg-K) 1.1775
1.0466 1.1025
Liquid Cp/Cv
1.5614
1.5494 1.56
Phase Vapor Phase Cp/Cv
1.2551
1.2282 1.2458
Liquid Phase Molar Mass
76.898
93.268 88.844
Vapor Phase Molar Mass
76.898
93.268 88.844
Liquid Phase Thermal Conductivity
(mW/m-K) 91.971
85.39 85.221
Vapor Phase Thermal Conductivity
(mW/m-K) 14.609
13.727 14.395
Liquid Phase Viscosity
(uPa-s) 170.81
181.69 177.55
Vapor Phase Viscosity
(uPa-s) 10.872
11.669 11.514
ODP 0 0 0

R152a and R125 are commercially available or may be prepared by methods known in the art.
Tetrafluoroethane is commercially available or may be prepared by methods know in the art, such as by the hydrogenation of 1,1-dichloro-1,2,2,2-tetrafluoroethane (i.e., CCI2FCF3 or CFC-114a) to 1,1 ,1,2-tetrafluoroethane.
It is against this and other backgrounds, which shall be filed in a detailed manner in complete specifications, in due course, the present invention is brought out and explained in following non-limiting examples.
It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention and specific examples provided herein without departing from the spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention that come within the scope of any claims and their equivalents.

EXAMPLE
The compositions of the present invention were prepared by adding different components in increasing order of vapour pressure and were analyzed using ASPEN.

WE CLAIM:

1. A composition comprising 10% by weight to 90% by weight of R134a and 10% by weight to 90% by weight of R152a.
2. The composition as claimed in claim 1, further comprises 5% by weight to 15% by weight of R125.
3. The composition as claimed in claim 1, comprising 10% by weight to 40% by weight of R134a and 60% by weight to 90% by weight of R152a.
4. The composition as claimed in claim 1, comprising 45% by weight to 80% by weight of R134a; 15% by weight to 45% by weight of R152a; and 5% by weight to 15% by weight of R125.
5. The compositions as claimed in any of the preceding claims are used as blowing agent, cleaning solvent, aerosols, refrigerants, and heat transfer agents.
6. The aerosol composition as claimed in any of the preceding claims are used for degreasing or cleaning of solid surfaces, and for deposition of user products such as lubricants, paints, varnishes, or the like.
7. The compositions as claimed in any of the preceding claims have thermal conductivity comparable to the thermal conductivity of foams of HCFC-141b.

8. The composition as claimed in any of the preceding claims have zero ODP and provide environment friendly substitute for HCFC-141b.