[0001] The invention relates to certain non-flammable compositions comprising 1,1,1,3,3-pentafluorobutane
(R365mfc), 1,2-dichloroethylene, ethoxynonafluorobutane (HFE-7200) and a linear C1
to C3 alcohol, to mixtures comprising these non-flammable compositions and to their
use, especially as cleaning and/or drying agents for solid surfaces and for flushing,
especially of refrigeration systems.
[0002] Fully halogenated chlorofluorinated hydrocarbons (CFCs), in particular 1,1,2-trichloro-1,2,2-trifluoroethane
(CFC-113), were widely used as solvents in industry for degreasing and cleaning various
surfaces. In addition to their use in electronics in cleaning soldering, they were
also conventionally used for degreasing metal components or for cleaning mechanical
components of high quality and of high precision. In these various applications, CFC-113
was most often used in combination with other organic solvents, preferably in the
form of azeotropic or pseudo-azeotropic compositions. For example, CFC-113 was used
in combination with trans-1,2-dichloroethylene in compositions formerly known as Freon
® MCA and Freon
® SMT. Such compositions could also be used as cleaning agents in the refrigeration
industry.
[0003] However, CFC-113, as well as other fully halogenated chlorofluoroalkanes, was suspected
of being involved in the destruction of the stratospheric ozone layer.
[0004] Consequently, compositions with reportedly lower ozone-layer destruction potential
were disclosed in
WO 2000/56833 and include compositions of 1,1,1,3,3-pentafluorobutane and 1,1,1,2,3,4,4,5,5,5-decafluoropentane
or nonafluoromethoxybutane with the optional addition of trans-1,2-dichloruethylene
(tDCE), n-propyl bromide (nPB), acetone, methanol, ethanol or isopropanol.
[0005] In applications where the potential of fire is of concern, it is desirable for the
cleaning compositions to be non-flammable in both liquid and vapour phase, during
usage. Accordingly, one of the objectives of the present invention is to provide non-flammable
compositions.
[0006] During usage and/or when discharged to the atmosphere, a composition of a mixture
may change, what might cause the composition remaining or the composition being discharged
to become flammable or to exhibit unacceptable performance. Accordingly, it is another
objective of this invention to provide compositions forming azeotropes or pseudo-azeotropes.
[0007] The HFCs that have been proposed as replacement for CFCs might have not sufficient
solvency for electronics soils such as hydrocarbon or silicon oils and flux residues,
or soils of the refrigeration industry. Accordingly, it is yet another object of the
present invention to provide HFC-based cleaning compositions that exhibit acceptable
solubility for electronics soils notably suited for cleaning printed circuit boards
and/or soils in the refrigeration industry, notably as flushing agents for cleaning
air conditioning systems. One example of a measure of solvency power is the Kauri-butanol
value ("Kb value"). Accordingly, it is yet another objective of the invention to provide
a cleaning composition with an improved Kauri-butanol value.
[0008] Additionally, it is an objective of the present invention to provide compositions
with a low global warming potential (GWP) and/or with a low ozone-depletion potential.
[0009] There is still a need in the electronics and refrigeration industry for compositions
that provide advantageous compositions with regard to the aforementioned problems.
[0010] The compositions of the present invention solve one or more of at least the aforementioned
problems confronting the cleaning and refrigeration industries.
[0011] Consequently, the present invention relates to non-flammable compositions consisting
or consisting essentially of 1,1,1,3,3-pentafluorobutane (R365mfc) in a concentration
of 5-20 wt %, 1,2-dichloroethylene in a concentration of 30-88.9 wt %, ethoxynonafluorobutane
(HFE-7200) in a concentration of 1-40 wt %, and at least one linear C1 to C4 alcohol
in a concentration of 0.1-10 wt %, preferably consisting or consisting essentially
of 1,1,1,3,3-pentafluorobutane (R365mfc) in a concentration of 10-15 wt %, 1,2-dichloroethylene
in a concentration of 70-84.9 wt %, ethoxynonafluorobutane (HFE-7200) in a concentration
of 5-20 wt %, and at least one linear C1 to C4 alcohol in a concentration of 0.1-5
wt %, more preferably consisting or consisting essentially of 1,1,1,3,3-pentafluorobutane
(R365mfc) in a concentration of 10-15 wt %, 1,2-dichloroethylene in a concentration
of 75-79.1 wt %, ethoxynonafluorobutane (HFE-7200) in a concentration of 10-15 wt
%, and at least one linear C1 to C4 alcohol in a concentration of 0.1-5 wt %, even
more preferably consisting or consisting essentially of 1,1,1,3,3-pentafluorobutane
(R365mfc) in a concentration of 12-13 wt %, 1,2-dichloroethylene in a concentration
of 74-76 wt %, ethoxynonafluorobutane (HFE-7200) in a concentration of 10-11 wt %,
and at least one linear C1 to C4 alcohol in a concentration of 1-2 wt %.
[0012] The term "linear C1 to C4 alcohol" is intended to denote a compound including at
least on hydroxyl group attached to a non-branched alkyl chain. Very suitable examples
include methanol, ethanol, n-propanol, n-butanol and mixtures thereof. Methanol, ethanol,
and n-propanol are preferred, ethanol is especially preferred. Another C1 to C4 alcohol
is isobutanol.
[0013] Unless specified otherwise, the weight percentages in the present specification are
all relative to the total weight of the composition.
[0014] The term "flammable" is meant to denote any flammability determined according to
any applicable standard, and is preferably as defined in DIN/EN/ISO 13736.
[0015] The term "consisting essentially of" as used herein is intended to denote a composition
comprising the components as specified as well as other components in trace amounts
wherein the presence of the other components does not change the essential characteristics
of the specified subject matter.
[0016] HFE-7200 is commercially available from 3M and consists of the two isomers (CF
3)
2CFCF
2OC
2H
5 (CAS No. 163702-06-5) and CF
3CF
2CF
2CF
2OC
2H
5 (CAS No. 15 163702-05-4).
[0017] 1,2-Dichloroethylene exists in two isomeric forms, cis-1,2-dichloroethylene and trans-1,2-dichloroethylene.
For the purposes of the present invention, 1,2-dichloroethylene is understood to mean,
without distinction, one or the other isomer or a mixture of these. In a preferred
embodiment, the 1,2-dichloroethylene consists essentially of trans-1,2-dichloroethylene.
[0018] In another preferred embodiment, the compositions of the present invention are azeotropic
or pseudo-azeotropic. An azeotrope as used herein is a specific system containing
at least two components in which, at a given temperature and a given pressure, the
composition in the liquid phase is equal to the composition in the vapour phase. A
pseudo-azeotrope as used herein is a specific system containing at least two components
in which, at a given temperature and a given pressure, the composition in the liquid
phase is substantially equal to the composition in the vapour phase. In practice,
their composition remains substantially constant in solvent cleaning operations, as
well as in operations for recovering spent solvents by distillation.
[0019] In another preferred embodiment, the non-flammable compositions have a GWP of < 500,
preferably < 350, more preferably < 250, most preferably < 150. The Global Warming
Potential (GWP) as used herein is determined using the 100-yr ITH, IPCC2001 method.
[0020] The invention also relates to mixtures comprising the inventive non-flammable compositions
as described above and further comprising at least one propellant.
[0021] The propellant assists in the delivery of the composition to the point of use. Representative
propellants comprise air, nitrogen, carbon dioxide, difluoromethane, trifluoromethane,
fluorinated ethanes, especially 1,1-difluoroethane, 1,1,1-trifluoroethane, 1,1,2-trifluoroethane,
1,1,1,2-tetrafluoroethane, 1,1,2,2-tetrafluoroethane, and pentafluoroethane. The propellant
may be included in the composition in an amount of > 0, preferably equal to or more
than 5 parts, more preferably equal to or more than 10 parts by weight per 100 parts
by weight of the composition according to the invention. Preferably, the amount of
the propellant is equal to or less than 40 parts, preferably equal to or less than
30 parts by weight per 100 parts by weight of composition according to the invention.
Mixtures wherein the propellant is comprised in an amount of 1 to 25 parts per 100
parts of the composition according to the invention are especially suitable for flushing.
[0022] The mixture can further comprise a stabilizer. The stabilizer can be present in an
amount of up to or equal to 5 wt %, preferably up to or equal to 2 wt %, more preferably
up to or equal to 0.5 wt % relative to the total weight of the mixture. The stabilizer
is intended to stabilize the components of the composition against undesired side
reactions during storage, transportation or use. Examples of suitable stabilizers
are epoxides, unsaturated hydrocarbons, nitroalkanes, diketones, brominated compounds,
and other alcohols than the linear C1 to C4 alcohols according to the invention.
[0023] The compositions according to the invention can be used in the same applications
and according to the same techniques as the prior compositions based on CFC-113.
[0024] The compositions can be used, for example, as cleaning agents in general, especially
as surface cleaning agent, e.g. for cleaning parts, for example, precision parts,
made of plastics or inorganic material. The term "cleaning" includes, for example,
cleaning textiles, degreasing in general, for example, degreasing animal hides, surface
cleaning, for example cleaning, especially degreasing of metal, glass, or ceramics
parts; for example, cleaning of optical lenses, cleaning of electronic devices, e.g.
printed circuit boards contaminated by a pickling flux and residues from this flux,
or cleaning solid chemicals insoluble in the composition. Solid objects can be desiccated
to remove the water adsorbed at the surface of solid objects.
[0025] Accordingly, the present invention also relates to method of use of the non-flammable
compositions or the mixtures as described above as cleaning agents, preferably as
precision cleaning agents, or as degreasing agents. Preferably, the non-flammable
composition or the mixture is in the vapour phase during the cleaning. Especially
preferred is a method of use as a cleaning agent or as a degreasing agent for printed
circuit boards contaminated by a pickling flux and residues from this flux or as desiccating
agent for removing water adsorbed at the surface of solid objects. Alternatively,
they also can be used as mold-release agents or for defluxing electronic components
and for degreasing metals.
[0026] Also preferably, the propellant-containing mixtures are used for flushing of refrigeration
equipment. The interior surface of compression refrigeration equipment, for example,
used for climatisation of rooms, space for storing goods, or automobiles (mobile air
conditioning, MAC) sometimes needs cleaning from residues, for example, when the refrigerant
has to be changed, or had evaporated because of a leakage or has to be removed for
repair. The residue be located in lines or other parts of the apparatus, e.g. in the
compressor. The residue comprises refrigerant, compressor lubricant, e.g. mineral
oil, naphthenes or polyol ethers, metal particles or rust. By contact with the composition
according to the present invention, the inner surface of the equipment is recovered
substantially free of residue. The way of contacting is not critical. The composition
preferably is flushed in liquid phase through the equipment. The vapour pressure of
the propellant moves the composition through the equipment.
[0027] Accordingly, the present invention also relates to a method of use of the non-flammable
compositions as described above and preferably the mixtures as described above for
cleaning of interior surfaces of refrigeration equipment, especially by flushing the
refrigeration equipment. More preferably the refrigeration equipment is an air-conditioner.
[0028] The non-flammable compositions and the mixture of the present invention can even
can be applied as blowing agents for preparing plastic foams or for spraying liquids
or as refrigerants.
[0029] The compositions, with or without a propellant, can be prepared in a very simple
manner by mixing the constituents. Constituents which are gaseous at ambient pressure
and temperature can be added in liquid form under pressure or by adding them to the
other constituents under condensation.
[0030] The invention advantageously provides compositions which are non-flammable, despite
their content of 1,2-dichloroethylene and the linear C1 to C4 alcohols, which per
se are flammable.
[0031] The examples below, without implied limitation, illustrate the invention in a more
detailed way.
Examples
Example 1 : Preparation of a quaternary composition
[0032] Trans-1,2-dichoroethylene is mixed with 1,1,1,3,3-pentafluorobutane, ethoxynonafluorobutane
(HFE-7200) and ethanol in a weight ratio of 70:15:10:5. Flammability test with the
composition of example 1 :
[0033] The flammability test is performed according to DIN/EN/ISO 13736 in a closed cup
of 75 ml inner volume. The cup also comprises a stirrer and a probe to determine the
temperature of the liquid to be tested, and means to rise the temperature. In the
lid of the cup, a device is contained which allows to direct a test flame to the surface
of the liquid the combustibility of which has to be determined. The apparatus used
had a thermo detector which responds to fast rise of the measured temperature (indicating
that a flame occurred).
[0034] The stirrer rotated slowly (about 30 rpm). The liquid in the cup is slowly warmed
up. Whenever the temperature rose by 0.5°C, the test flame is ignited and it was checked
if the thermo sensor responded. The tested composition is non-flammable.
Example 2 : Use of the composition of example I for vapour degreasing
[0035] Metal parts can be greased on the surface to protect them against corrosion. Adhering
grease can also be caused by the application of drawing wax, drawing grease or drawing
oil during shaping the metal parts. The step of cleaning high-precision metal parts
is performed in a vapour degreaser.
[0036] A vapour immersion unit which has two solvent-filled sumps can be applied. A boil
cleaning tank comprises a solvent mixture which, additional to a higher-boiling solvent
component additionally comprises the non-flammable composition described above. A
rinsing tank only comprises the non-flammable composition described above.
[0037] The metal parts are assembled in a basket and immersed into the boil cleaning tank
to dissolve adhering grease. They are then removed and immersed into the rinsing tank
wherein adhering solvent mixture from the boil cleaning tank is rinsed. The parts
then are covered with the lower-boiling composition of the rinsing tank. The basket
is then removed from the rinsing tank and kept in the gas space above tanks. The solvent
adhering on the surface of the metal parts passes into the vapour phase. Near the
top of the vapour degreaser are three sets of cooled coils where the vapour condenses
before it can escape from the unit. The condensed vapour flows back to a clean condensate
tank and can be reused. A part of the vapour is fed to a drying unit to remove water
from it. The degreased dry metal parts can then be removed from the vapour degreaser.
Example 3 : Preparation of a mixture comprising a stabilizer and a propellant
[0038] 15 wt % 1,1,1,3,3-pentafluorobutane (R365mfc), 70 wt % 1,2-trans-dichloroethylene
which comprises about 0.5 wt % isopropanol as stabilizer, and 10 wt % ethoxynonafluorobutane
(HFE-7200) and 5 wt % ethanol are mixed. This basic composition is filled into a container,
and 10 parts 1,1,1,2-tetrafluoroethane are condensed into the container.
Example 4 : Flushing MAC apparatus using the composition of the present invention
[0039] The mixture of example 3 is applied in a method for flushing a mobile air conditioning
apparatus.
[0040] The refrigerant is removed beforehand. A storage tank containing the composition
is connected to the apparatus, and respective valves are opened. The composition is
flushed through the lines and parts of the apparatus including the compressor. Residual
oil and solids are removed during the treatment. The composition after leaving the
apparatus is collected in a tank and can be conditioned for reuse by distillation.
The flushed apparatus is clean and degreased and can be refilled with refrigerating
agent.
[0041] The inventive compositions show an improved solvent strength, especially for inorganic
and /or polar organic impurities. This is a benefit especially for removing solder-,
brazing-, inorganic impurities as well as for the use in water displacement equipment.
[0042] Surprisingly, it has been found that inventive mixtures also show azeotropic behaviour.
1. A non-flammable composition consisting or consisting essentially of
(a) 1,1,1,3,3-pentafluorobutane (R365mfc) in a concentration of 5-20 wt %,
(b) 1,2-dichloroethylene in a concentration of 30-88.9 wt %,
(c) ethoxynonafluorobutane (HFE-7200) in a concentration of 1-40 wt %, and
(d) at least one linear C1 to C4 alcohol in a concentration of 0.1-10 wt %.
2. The non-flammable composition of claim 1 consisting or consisting essentially of
(a) 1,1,1,3,3-pentafluorobutane (R365mfc) in a concentration of 10-15 wt %,
(b) 1,2-dichloroethylene in a concentration of 70-84.9 wt %,
(c) ethoxynonafluorobutane (HFE-7200) in a concentration of 5-20 wt %, and
(d) at least one linear C1 to C4 alcohol in a concentration of 0.1-5 wt %.
3. The non-flammable composition of claim 2 consisting or consisting essentially of
(a) 1,1,1,3,3-pentafluorobutane (R365mfc) in a concentration of 10-15 wt %,
(b) 1,2-dichloroethylene in a concentration of 75-79.1 wt %,
(c) ethoxynonafluorobutane (HFE-7200) in a concentration of 10-15 wt %, and
(d) at least one linear C1 to C4 alcohol in a concentration of 0.1-5 wt %.
4. The non-flammable composition of claim 3 consisting or consisting essentially of
(a) 1,1,1,3,3-pentafluorobutane (R365mfc) in a concentration of 12-13 wt %,
(b) 1,2-dichloroethylene in a concentration of 74-76 wt %,
(c) ethoxynonafluorobutane (HFE-7200) in a concentration of 10-11 wt %, and
(d) at least one linear C1 to C4 alcohol in a concentration of 1-2 wt %.
5. The non-flammable composition of any one of claims 1 to 4 wherein the linear C1 to
C4 alcohol is methanol, ethanol or propanol, preferably the linear C1 to C4 alcohol
is ethanol.
6. The non-flammable composition of any one of claims 1 to 5 which is azeotropic.
7. The non-flammable composition of any one of claims 1 to 5 which is pseudo-azeotropic.
8. The non-flammable composition of any one of claims 1 to 7 which has a GWP of < 500,
preferably < 350, more preferably < 250, most preferably < 150.
9. A mixture comprising the non-flammable composition of any one of claims 1 to 8 and
further comprising at least one propellant.
10. The mixture of claim 9 wherein the propellant is comprised in an amount of 1 to 25
parts per 100 parts of the non-flammable composition.
11. A method of use of the non-flammable composition of any one of claims 1 to 8 or the
mixture of any one of the claims 9 to 11 as a cleaning agent, preferably as precision
cleaning agent, or as degreasing agent.
12. The method of use of claim 11, wherein the non-flammable composition is in the vapour
phase.
13. The method of use of any one of claims 11 to 12 as a cleaning agent or as a degreasing
agent for printed circuit boards contaminated by a pickling flux and residues from
this flux or as desiccating agent for removing water adsorbed at the surface of solid
objects.
14. A method of use of the non-flammable composition of any one of the claims 1 to 8 or
the mixture of any one of the claims 9 to 10 for cleaning of interior surfaces of
refrigeration equipment, especially by flushing the refrigeration equipment.