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Description  |
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BACKGROUND OF THE INVENTION
The present invention relates to a method of cleaning a surface of a
substrate using hydrochlorofluorocarbons as solvents.
Vapor degreasing and solvent cleaning with fluorocarbon based solvents have
found widespread use in industry for the degreasing and otherwise cleaning
of solid surfaces, especially intricate parts and difficult to remove
soils.
In its simplest form, vapor degreasing or solvent cleaning consists of
exposing a room-temperature object to be cleaned to the vapors of a
boiling solvent. Vapors condensing on the object provide clean distilled
solvent to wash away grease or other contamination. Final evaporation of
solvent from the object leaves behind no residue as would be the case
where the object is simply washed in liquid solvent.
For difficult to remove soils where elevated temperature is necessary to
improve the cleaning action of the solvent, or for large volume assembly
line operations where the cleaning of metal parts and assemblies must be
done efficiently and quickly, the conventional operation of a vapor
degreaser consists of immersing the part to be cleaned in a sump of
boiling solvent which removes the bulk of the soil, thereafter immersing
the part in a sump containing freshly distilled solvent near room
temperature, and finally exposing the part to solvent vapors over the
boiling sump which condense on the cleaned part. In addition, the part can
also be sprayed with distilled solvent before final rinsing.
Vapor degreasers suitable in the above-described operations are well known
in the act. For example, Sherliker et al. in U.S. Pat. No. 3,085,918
disclose such suitable vapor degreasers comprising a boiling sump, a clean
sump, a water separator, and other ancilliary equipment.
Cold cleaning is another application where a number of solvents are used.
In most cold cleaning applications, the soiled part is either immersed in
the fluid or wiped with rags or similar objects soaked in solvents.
Fluorocarbon solvents, such as trichlorotrifluoroethane, have attained
widespread use in recent years as effective, nontoxic, and nonflammable
agents useful in degreasing applications and other solvent cleaning
applications. Trichlorotrifluoroethane has been found to have satisfactory
solvent power for greases, oils, waxes and the like. It has therefore
found widespread use for cleaning electric motors, compressors, heavy
metal parts, delicate precision metal parts, printed circuit boards,
gyroscopes, guidance systems, aerospace and missile hardware, aluminum
parts and the like. Trichlorotrifluoroethane has two isomers:
1,1,2-trichloro-1,2,2-trifluoroethane (known in the art as CFC-113) and
1,1,1-trichloro-2,2,2-trifluoroethane (known in the art as CFC-113a).
Chlorofluorocarbons (CFC) such as 113 are suspected of causing
environmental problems in connection with the ozone layer. In Aug. 1988,
the U.S. Environmental Protection Agency issued its final rules ordering a
freeze on CFC production including CFC-113 at 1986 levels by mid-1989.
Additional 20% and 50% cuts in CFC production are scheduled for 1993 and
1998.
In response to the need for stratospherically safe materials, substitutes
have been developed and continue to be developed. Research Disclosure
14623 (June 1978) reports that 1,1-dichloro-2,2,2-trifluoroethane (known
in the art as HCFC-123) is a useful solvent for degreasing and defluxing
substrates. U.S. Pat. No. 4,465,609 teaches that HCFC-123 is useful as a
heat transfer fluid in heat pumps and thermal engines. In the EPA
"Findings of the Chlorofluorocarbon Chemical Substitutes International
Committee", EPA No. 600/9-88-009 (Apr. 1988), it was reported on pages
C-22 and C-23 that HCFC-123 and 1-fluoro-1,1-dichloroethane (known in the
art as HCFC-141b) have potential as replacements for CFC-113 as cleaning
agents.
A wide variety of consumer parts is produced on an annual basis in the
United States and abroad. Many of these parts have to be cleaned during
various manufacturing stages in order to remove undesirable contaminants.
These parts are produced in tremendous quantities and as a result,
substantial quantities of solvents are used to clean them. It is apparent
that the solvent used must be compatible with the material to be cleaned.
During our analysis of the use of HCFC-123, HCFC-123a, and HCFC-141b as
replacements for CFC-113, we discovered that upon the application of the
aforementioned solvents to certain substrates, the HCFC-123, HCFC-123a,
and HCFC-141b attacked the substrates so as to render the substrates
useless for their intended application. Details of these experiments are
set forth more fully below.
It is an object of the invention to provide a novel class of solvents for
cleaning substrates.
It is another object of the invention to provide such a novel class of
solvents which are stratospherically safe.
Yet another object of the invention is to provide such solvents which do
not detrimentally attack a variety of substrates which are used in various
industrial processes.
SUMMARY OF THE INVENTION
The objects of the invention are achieved by treating the surface with a
solvent comprising a compound of the formula
CH.sub.a Cl.sub.b F.sub.c (CF.sub.2).sub.d CH.sub.e Cl.sub.f F.sub.g
wherein a+e ranges from 1 to 4, b+f equals 2, c+g ranges from 0 to 3, d is
from 1 to 4, a+b+c-3, and e+f+g=3.
Kyodo News Service, Tokyo, Japan reported on Feb. 6, 1989 that HCFC-225CA
and HCFC-225CB have the properties of CFC-113 as a cleaning agent.
The previously cited EPA paper lists
1,1-dichloro-2,2,3,3,3-pentafluoropropane on page C-37, line 5 as a
potential CFC substitute but reports that a significant amount of
developmental work is needed in toxicological testing, physical property
measurements, and applications testing for such potential substitutes. The
paper does not teach that 1,1-dichloro-2,2,3,3,3-pentafluoropropane is
useful as a solvent. British Patent No. 1,562,026 teaches that
1,1-dichloro-2,2,3,3,3-pentafluoropropane is useful as a blowing agent but
the reference does not teach that
1,1-dichloro-2,2,3,3,3-pentafluoropropane is useful as a solvent. U.S.
Pat. No. 2,838,457 teaches that dichlorotrifluoropropane is a useful
additive for hydraulic oil.
In addition to their usefulness in cleaning applications, the present
solvents are advantageous because they have a low ozone depletion
potential.
The present solvents may be used in liquid form in many applications where
HCFC-123, HCFC-123a and HCFC-141b would be in vapor form. As a result, the
present solvents are easier to contain and minimize solvent losses.
As such, the present invention responds to the need for stratospherically
safe solvents for use in cleaning substrates wherein the substrate is not
detrimentally attacked by the solvent.
Other advantages of the present invention will become apparent from the
following description and appended claims.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The solvents used comprise a compound of the formula
CH.sub.a Cl.sub.b F.sub.c (CF.sub.2).sub.d CH.sub.e Cl.sub.f F.sub.g
wherein a+e ranges from 1 to 4, b+f equals 2, c+g ranges from 0 to 3, d is
from 1 to 4, a+b+c-3, and e+f+g=3.
Illustrative examples of useful solvents include
1,3-dichloro-2,2-difluoropropane; 1,3-dichloro-1,2,2-trifluoropropane;
1,3-dichloro-1,1,2,2-tetrafluoropropane;
1,3-dichloro-1,2,2,3-tetrafluoropropane;
1,3-dichloro-1,1,2,2,3-pentafluoropropane;
1,1-dichloro-2,2-difluoropropane; 1,1-dichloro-2,2,3-trifluoropropane;
1,1-dichloro-2,2,3,3-tetrafluoropropane;
1,1-dichloro-2,2,3,3,3-pentafluoropropane;
1,1-dichloro-1,2,2-trifluoropropane;
1,1-dichloro-1,2,2,3-tetrafluoropropane; and
1,1-dichloro-1,2,2,3,3-pentafluoropropane.
Other examples of useful solvents include
1,4-dichloro-2,2,3,3-tetrafluorobutane;
1,4-dichloro-1,2,2,3,3-pentafluorobutane;
1,4-dichloro-1,1,2,2,3,3-hexafluorobutane;
1,4-dichloro-1,2,2,3,3,4-hexafluorobutane;
1,4-dichloro-1,1,2,2,3,3,4-heptafluorobutane;
1,1-dichloro-2,2,3,3-tetrafluorobutane;
1,1-dichloro-2,2,3,3,4-pentafluorobutane;
1,1-dichloro-2,2,3,3,4,4-hexafluorobutane;
1,1-dichloro-2,2,3,3,4,4,4-heptafluorobutane;
1,1-dichloro-1,2,2,3,3-pentafluorobutane;
1,1-dichloro-1,2,2,3,3,4-hexafluorobutane; and
1,1-dichloro-1,2,2,3,3,4,4-heptafluorobutane.
Further examples of useful solvents include
1,5-dichloro-2,2,3,3,4,4-hexafluoropentane;
1,5-dichloro-1,2,2,3,3,4,4-heptafluoropentane;
1,5-dichloro-1,1,2,2,3,3,4,4-octafluoropentane;
1,5-dichloro-1,2,2,3,3,4,4,5-octafluoropentane;
1,5-dichloro-1,1,2,2,3,3,4,4,5-nonafluoropentane;
1,1-dichloro-2,2,3,3,4,4-hexafluoropentane;
1,1-dichloro-2,2,3,3,4,4,5-heptafluoropentane;
1,1-dichloro-2,2,3,3,4,4,5,5-octafluoropentane;
1,1-dichloro-2,2,3,3,4,4,5,5,5-nonafluoropentane;
1,1-dichloro-1,2,2,3,3,4,4-heptafluoropentane;
1,1-dichloro-1,2,2,3,3,4,4,5-octafluoropentane; and
1,1-dichloro-1,2,2,3,3,4,4,5,5-nonafluoropentane.
Additional examples of useful solvents include
1,6-dichloro-2,2,3,3,4,4,5,5-octafluorohexane;
1,6-dichloro-1,2,2,3,3,4,4,5,5-nonafluorohexane;
1,6-dichloro-1,1,2,2,3,3,4,4,5,5-decafluorohexane;
1,6-dichloro-1,2,2,3,3,4,4,5,5,6-decafluorohexane;
1,6-dichloro-1,1,2,2,3,3,4,4,5,5,6-undecafluorohexane;
1,1-dichloro-2,2,3,3,4,4,5,5-octafluorohexane;
1,1-dichloro-2,2,3,3,4,4,5,5,6-nonafluorohexane;
1,1-dichloro-2,2,3,3,4,4,5,5,6,6-decafluorohexane;
1,1-dichloro-2,2,3,3,4,4,5,5,6,6,6-undecafluorohexane;
1,1-dichloro-1,2,2,3,3,4,4,5,5-nonafluorohexane;
1,1-dichloro-1,2,2,3,3,4,4,5,5,6-decafluorohexane; and
1,1-dichloro-1,2,2,3,3,4,4,5,5,6,6-undecafluorohexane.
The preferred solvents are the aforementioned pentanes, butanes, and
propanes. In a more preferred embodiment, the solvents are
1,1-dichloro-2,2,3,3,3-pentafluoropropane and
1,3-dichloro-1,1,2,2,3-pentafluoropropane. In another more preferred
embodiment, the solvents are the pentanes, butanes, and propanes wherein
c+g ranges from 0 to 2; the most preferred solvent is
1,1-dichloro-1,2,2-trifluoropropane.
These solvents are readily prepared from commercially available materials
by standard and well-known organic syntheses techniques. For example, to
prepare 1,1-dichloro-2,2,3,3,3-pentafluoropropane,
2,2,3,3,3-pentafluoro-1-propanol and p-toluenesulfonate chloride are
reacted together to form 2,2,3,3,3-pentafluoropropyl-p-toluenesulfonate.
Then, N-methylpyrrolidone, lithium chloride, and the
2,2,3,3,3-pentafluoropropyl-p-toluenesulfonate are reacted together to
form 1-chloro-2,2,3,3,3-pentafluoropropane. Chlorine and the
1-chloro-2,2,3,3,3-pentafluoropropane are then reacted together to form
1,1-dichloro-2,2,3,3,3-pentafluoropropane.
For example, to prepare 1,3-dichloro-1,1,2,2,3-pentafluoropropane,
2,2,3,3-tetrafluoropropanol, tosyl chloride, and water are reacted
together to form 2,2,3,3-tetrafluoropropyl p-toluenesulfonate. Then,
N-methylpyrrolidone, potassium fluoride, and the 2,2,3,3-tetrafluoropropyl
p-toluenesulfonate are reacted together to form
1,1,2,2,3-pentafluoropropane. Then, chlorine and the
1,1,2,2,3-pentafluoropropane are reacted to form
1,1,3-trichloro-1,2,2,3,3-pentafluoropropane. Finally, isopropanol and the
1,1,3-trichloro-1,2,2,3,3-pentafluoropropane are reacted to form
1,3-dichloro-1,1,2,2,3-pentafluoropropane.
For example, to prepare 1,1-dichloro-1,2,2-trifluoropropane, antimony
trifluoride, bromine, and 2,2-dichloropropane are reacted together to form
2,2-difluoropropane. Then, chlorine and the 2,2-difluoropropane are
reacted to form 1,1,1-trichloro-2,2-difluoropropane. Finally, antimony
trifluoride, chlorine, and the 1,1,1-trichloro-2,2-difluoropropane are
reacted to form 1,1-dichloro-1,2,2-trifluoropropane.
For example, to prepare 1,1-dichloro-2,2,3,3,4,4,4-heptafluorobutane,
2,2,3,3,4,4,4-heptafluorobutanol and p-toluenesulfonyl chloride are
reacted to form 2,2,3,3,4,4,4-heptafluorobutyl-p-toluenesulfonate. Then,
N-methylpyrrolidone, lithium chloride, and the
2,2,3,3,4,4,4-heptafluorobutyl-p-toluenesulfonate are reacted to form
1-chloro-2,2,3,3,4,4,4-heptafluorobutane. Finally, chlorine and the
1-chloro-2,2,3,3,4,4,4-heptafluorobutane are reacted to form the
1,1-dichloro-2,2,3,3,4,4,4-heptafluorobutane.
For example, to prepare 1,5-dichloro-1,1,2,2,3,3,4,4,5-nonafluoropentane,
the process for the preparation of
1,3-dichloro-1,1,2,2,3-pentafluoropropane set forth above is followed
except that octafluoropentanol is used as the starting material.
For example, to prepare
1,1-dichloro-2,2,3,3,4,4,5,5,6,6,6-undecafluorohexane, CF.sub.3
(CF.sub.2).sub.4 CH.sub.2 OH is prepared by NaBH.sub.4 or LiAlH.sub.4
reduction of CF.sub.3 (CF.sub.2).sub.4 COOEt or by reduction of CF.sub.3
(CF.sub.2).sub.4 COOH. The alcohol is then converted into the
1,1-dichloro-2,2,3,3,4,4,5,5,6,6,6-undecafluorohexane in the same manner
as described above for the conversion of 2,2,3,3,3-pentafluoropropane into
1,1-dichloro-2,2,3,3,3-pentafluoropropane.
Additives such as rust inhibitors, surfactants, corrosion inhibitors,
decomposition inhibitors, acid scavengers, antioxidants, and emulsifiers
may be added to the solvents in order to obtain additional desired
properties. For example, alcohols can be added which enable the solvents
to be used to remove solder fluxes such as used on printed circuit boards.
The present method removes most contaminants from the surface of a
substrate. For example, the present method removes organic contaminants
such as mineral oils from the surface of a substrate. Under the term
"mineral oils", both petroleum-based and petroleum-derived oils are
included. Lubricants such as engine oil, machine oil, and cutting oil are
examples of petroleum-derived oils.
The present method also removes water from the surface of a substrate. The
method may be used in the single-stage or multi-stage drying of objects.
The present method cleans the surface of inorganic and organic substrates.
Examples of inorganic substrates include metallic substrates, ceramic
substrates, and glass substrates. Examples of organic substrates include
polymeric substrates such as polycarbonate, polystyrene, and
acrylonitrile-butadiene-styrene. The method also cleans the surface of
natural fabrics such as cotton, silk, fur, suede, leather, linen, and
wool. The method also cleans the surface of synthetic fabrics such as
polyester, rayon, acrylics, nylon, and blends thereof, and blends of
synthetic and natural fabrics. It should also be understood that
composites of the foregoing materials may be cleaned by the present
method. The present method is particularly useful in cleaning the surface
of polycarbonate, polystyrene and ABS substrates.
The present method may be used in vapor degreasing, solvent cleaning, cold
cleaning, dewatering, and dry cleaning. In these uses, the object to be
cleaned is immersed in one or more stages in the liquid and/or vaporized
solvent or is sprayed with the liquid solvent. Elevated temperatures,
ultrasonic energy, and/or agitation may be used to intensify the cleaning
effect.
HCFC-243CC may have enhanced stability with aluminum.
The present invention is more fully illustrated by the following
non-limiting Examples.
All Examples were performed in small volume cylindrical containers
(13.times.100 mm) for comparative purposes only. It should be understood
that to maximize cleaning performance, the ratio of the volume of the
solvent to the volume of the work piece to be cleaned should be maximized.
This may be accomplished by using a larger sump. Further improvements in
cleaning performance may be accomplished by using commercial degreasing
equipment and immersing the work piece in a boil sump, followed by a cold
sump, and followed by a vapor rinse.
The term "severely attacked" as used in the results of the Examples means
that the surface was deformed.
The term "cleaned off" as used in the results of the Examples means that no
residue was discerned on the surface of the substrate based on a visual
observation thereof.
The term "essentially removed" as used in the results of the Examples means
that at least 95% of the contaminant was removed from the surface of the
substrate.
EXAMPLES 1-3 AND COMPARATIVES 1-3
Comparatives 1-3 show that HCFC-123, HCFC-123a, and HCFC-141b attack
polystyrene substrates upon cleaning light mineral oil from them while the
present solvents do not.
The compounds used were as follows:
______________________________________
Example Compound
______________________________________
Comparative 1 HCFC-123
Comparative 2 HCFC-123a
Comparative 3 HCFC-141b
Example 1 1,1-dichloro-2,2,3,3,3,-penta-
fluoropropane
Example 2 1,3-dichloro-1,2,2,3,3,-penta-
fluoropropane
Example 3 1,1-dichloro-1,2,2,-trifluoro-
propane
______________________________________
Commercially available HCFC-123, HCFC-123a, and HCFC-141b were used. The
present solvents were prepared according to the aforementioned syntheses.
Strips of polystyrene which measured 0.125".times.0.25".times.2" (0.3175
cm.times.0.635 cm.times.5.08 cm) had coatings of light mineral oil
thereon. The strips were submerged in each of the foregoing solvents at
their boiling points for 10 minutes. Visual observations were made
regarding changes in the appearance of the polystyrene strip. The results
are reported in Table 1 below.
TABLE 1
______________________________________
Example Result
______________________________________
Comp. 1 The polystyrene was severely attacked.
Comp. 2 The polystyrene was severely attacked.
Comp. 3 The polystyrene was severely attacked.
Ex. 1 The light mineal oil was cleaned off
the polystyrene strip. The solvent did
not attack the polystyrene.
Ex. 2 The light mineral oil was cleaned off
the polystyrene strip. The solvent did
not attack the polystyrene.
Ex. 3 The light mineral oil was cleaned off
the polystyrene strip. The solvent did
not attack the polystyrene.
______________________________________
These results indicate that HCFC-123, HCFC-123a, and HCFC-141b are
unsuitable for cleaning polystyrene substrates because they attack the
polymeric material. In contrast, the present solvents of Examples 1,2, and
3 are suitable for cleaning light mineral oil from polystyrene substrates
and they do not attack the polymeric material.
EXAMPLES 4-6 AND COMPARATIVES 4-6
Comparatives 4-6 show that HCFC-123, HCFC-123a, and HCFC-141b attack
polystyrene substrates upon cleaning 20W motor oil from them while the
present solvents do not.
The compounds used were as follows:
______________________________________
Example Compound
______________________________________
Comparative 4 HCFC-123
Comparative 5 HCFC-123a
Comparative 6 HCFC-141b
Example 4 HCFC-225CA
Example 5 HCFC-225CB
Example 6 HCFC-243CC
______________________________________
Strips of polystyrene which measured 0.125".times.0.25".times.2" (0.3175
cm.times.0.635 cm.times.5.08 cm) had light coatings of 20W motor oil
thereon. The strips were submerged in each of the foregoing solvents at
the boiling points for 10 minutes. Visual observations were made regarding
changes in the appearance of the polystyrene. The results are reported in
Table 2 below.
TABLE 2
______________________________________
Example Result
______________________________________
Comp. 4 The polystyrene was severely attacked.
Comp. 5 The polystyrene was severely attacked.
Comp. 6 The polystyrene was severely attacked.
Ex. 4 The 20W motor oil was essentially
removed from the polystyrene strip.
The solvent did not attack the
polystyrene.
Ex. 5 The 20W motor oil was essentially
removed from the polystyrene strip.
The solvent did not attack the
polystyrene.
Ex. 6 The 20W motor oil was cleaned off the
polystyrene strip. The solvent did not
attack the polystyrene.
______________________________________
These results also indicate that HCFC-123, HCFC-123a and HCFC-141b are
unsuitable for cleaning polystyrene substrates because they attack the
polymeric material. In contrast, the present solvents of Examples 4, 5 and
6 are suitable for cleaning 20W motor oil from polystyrene substrates and
they do not attack the polymeric material.
EXAMPLES 7-9 AND COMPARATIVES 7-9
Comparatives 7-9 show that HCFC-123, HCFC-123a, and HCFC-141b attack
polycarbonate substrates upon cleaning light mineral oil from them while
the present solvents do not.
The compounds used were as follows:
______________________________________
Example Compound
______________________________________
Comparative 7 HCFC-123
Comparative 8 HCFC-123a
Comparative 9 HCFC-141b
Example 7 1,1-dichloro-2,2,3,3,3-penta-
fluoropropane
Example 8 1,3-dichloro-1,2,2,3,3-penta-
fluoropropane
Example 9 1,1-dichloro-1,2,2-trifluor-
propane
______________________________________
Strips of polycarbonate which measured 0.125".times.0.25".times.2" (0.3175
cm.times.0.635 cm.times.5.08 cm) had coatings of light mineral oil
thereon. The strips were submerged in each of the foregoing solvents at
their boiling points for 10 minutes. Visual observations were made
regarding changes in the appearance of the polycarbonate. The results are
listed in Table 3 below.
TABLE 3
______________________________________
Example Result
______________________________________
Comp. 7 The polycarbonate surface turned cloudy.
Comp. 8 The polycarbonate was attacked and the
surface turned cloudy.
Comp. 9 The polycarbonate turned cloudy with
some streaking
Ex. 7 The light mineral oil was essentially
removed from the polycarbonate strip.
The solvent did not attack the
polycarbonate.
Ex. 8 The light mineral oil was essentially
removed from the polycarbonate strip.
The solvent did not attack the
polycarbonate.
Ex. 9 The light mineral oil was essentially
removed from the polycarbonate strip.
The solvent did not attack the
polycarbonate.
______________________________________
These results indicate that HCFC-123, HCFC-123a, and HCFC-141b are
unsuitable for cleaning polycarbonate substrates because they attack the
polymeric material. In contrast, the present solvents of Examples 7, 8 and
9 are suitable for essentially removing light mineral oil from
polycarbonate substrates and they do not attack the polymeric material.
EXAMPLES 10-12 AND COMPARATIVES 10-12
Comparatives 10-12 show that HCFC-123, HCFC-123a and HCFC-141b attack
polycarbonate substrates upon cleaning 20W motor oil from them while the
present solvents do not.
The compounds used were as follows:
______________________________________
Example Compound
______________________________________
Comparative 10 HCFC-123
Comparative 11 HCFC-123a
Comparative 12 HCFC-141b
Example 10 HCFC-225CA
Example 11 HCFC-225CB
Example 12 HCFC-243CC
______________________________________
Strips of polycarbonate which measured 0.125".times.0.25".times.2" (0.3175
cm.times.0.635 cm.times.5.08 cm) had coatings of 20W motor oil thereon.
The strips were submerged in each of the foregoing solvents at their
boiling points for 10 minutes. Visual observations were made regarding
changes in the appearance of the polycarbonate. The results are reported
in Table 4 below.
TABLE 4
______________________________________
Example Result
______________________________________
Comp. 10 The polycarbonate surface turned cloudy.
Comp. 11 The polycarbonate surface was attacked
and turned cloudy.
Comp. 12 The polycarbonate turned cloudy with
some streaking.
Ex. 10 The 20W motor oil was essentially
removed from the polycarbonate strip.
The solvent did not attack the
polycarbonate.
Ex. 11 The 20W motor oil was essentially
removed from the polycarbonate strip.
The solvent did not attack the
polycarbonate.
Ex. 12 The 20W motor oil was cleaned off the
polycarbonate strip. The solvent did
not attack the polycarbonate.
______________________________________
These results indicate that HCFC-123, HCFC-123a, and HCFC-141b are
unsuitable for cleaning polycarbonate substrates because they attack the
polymeric material. In contrast, the present solvents of Examples 10, 11
and 12 are suitable for essentially removing 20W motor oil from
polycarbonate substrates and they do not attack the polymeric material.
EXAMPLES 13-40
The present method described in Examples 1-3 is used to clean the following
contaminants from the following substrates by using the listed solvents.
Substantially the same results are obtained, that is to say, the
contaminants are removed from the substrates without the substrates being
attacked.
__________________________________________________________________________
Ex. Solvent Contaminant
Substrate
__________________________________________________________________________
13 1,3-dichloro-2,2-difluoropropane
engine oil
metal
14 1,3-dichloro-1,2,2-trifluoropropane
machine oil
ceramic
15 1,1-dichloro-2,2-difluoropropane
cutting oil
glass
16 1,1-dichloro-2,2,3,3-tetrafluoropropane
water glass
17 1,4-dichloro-2,2,3,3-tetrafluorobutane
engine oil
cotton
18 1,4-dichloro-1,2,2,3,3-pentafluorobutane
machine oil
wool
19 1,4-dichloro-1,1,2,2,3,3-hexafluorobutane
cutting oil
metal
20 1,4-dichloro-1,1,2,2,3,3,4-heptafluoro-
water ceramic
butane
21 1,1-dichloro-2,2,3,3,-tetrafluorobutane
engine oil
glass
22 1,1-dichloro-2,2,3,3,4-pentafluorobutane
machine oil
cotton
23 1,1-dichloro-2,2,3,3,4,4-hexafluorobutane
cutting oil
wool
24 1,1-dichloro-2,2,3,3,4,4,4,-heptafluoro-
water metal
butane
25 1,5-dichloro-2,2,3,3,4,4-hexafluoropentane
engine oil
ceramic
26 1,5-dichloro-1,2,2,3,3,4,4-heptafluoro-
machine oil
glass
pentane
27 1,5-dichloro-1,1,2,2,3,3,4,4-octafluoro-
cutting oil
cotton
pentane
28 1,5-dichloro-1,1,2,2,3,3,4,4,5-nonafluoro-
cutting oil
wool
pentane
29 1,1-dichloro-2,2,3,3,4,4,-hexafluoropentane
engine oil
wool
30 1,1-dichloro-2,2,3,3,4,4,5-heptafluoro-
machine oil
metal
pentane
31 1,1-dichloro-2,2,3,3,4,4,5,5-octafluoro-
cutting oil
ceramic
pentane
32 1,1-dichloro-2,2,3,3,4,4,5,5,5-nonafluoro-
engine oil
metal
pentane
33 1,6-dichloro-2,2,3,3,4,4,5,5-octafluoro-
machine oil
ceramic
hexane
34 1,6-dichloro-1,2,2,3,3,4,4,5,5-hexafluoro-
cutting oil
glass
hexane
35 1,6-dichloro-1,2,2,3,3,4,4,5,5,6-deca-
water glass
fluorohexane
36 1,6-dichloro-1,1,2,2,3,3,4,4,5,5,6-undeca-
engine oil
cotton
fluorohexane
37 1,1-dichloro-2,2,3,3,4,4,5,5-octafluoro-
machine oil
wool
hexane
38 1,1-dichloro-1,2,2,3,3,4,4,5,5-nonafluoro-
cutting oil
metal
hexane
39 1,1-dichloro-1,2,2,3,3,4,4,5,5,6-deca-
water ceramic
fluorohexane
40 1,1,-dichloro-1,2,2,3,3,4,4,5,5,6,6-undeca-
engine oil
glass
fluorohexane
__________________________________________________________________________
EXAMPLES 41-43 AND COMPARATIVES 41-43
Comparatives 41-43 show that HCFC-123, HCFC-123a and HCFC-141b attack ABS
substrates upon cleaning light mineral oil from them while the present
solvents do not.
The compounds used were as follows:
______________________________________
Example Compound
______________________________________
Comparative 41 HCFC-123
Comparative 42 HCFC-123a
Comparative 43 HCFC-141b
Example 41 HCFC-225CA
Example 42 HCFC-225CB
Example 43 HCFC-243CC
______________________________________
Strips of acrylonitrile-butadiene-styrene which measured
0.125".times.0.25".times.2" (0.3175 cm.times.0.635 cm.times.5.08 cm) had
coatings of light mineral oil thereon. The strips were submerged in each
of the foregoing solvents at their boiling points for 10 minutes. One side
of the ABS used was smooth while the other side was stippled. Visual
observations were made regarding changes in the appearance of the ABS. The
results are reported in Table 5 below.
TABLE 5
______________________________________
Example Result
______________________________________
Comp. 41 The solvent severely attacked the ABS.
Comp. 42 The solvent severely attacked the ABS.
Comp. 43 The solvent removed most of the
stippling.
Ex. 41 The light mineral oil was essentially
removed from the ABS strip. The
solvent did not attack the ABS.
Ex. 42 The light mineral oil was essentially
removed from the ABS strip. The solvent
did not attack the ABS.
Ex. 43 The light mineral oil was essentially
removed from the ABS strip. The
solvent did not attack the ABS.
______________________________________
These results indicate that HCFC-123, HCFC-123a, and HCFC-141b are
unsuitable for cleaning ABS substrates because they attack the polymeric
material. In contrast, the present solvents of Examples 41, 42, and 43 are
suitable for essentially removing light mineral oil from ABS and they do
not attack the polymeric material.
EXAMPLES 44-46 AND COMPARATIVES 44-46
Comparatives 44-46 show that HCFC-123, HCFC-123a, and HCFC-141b attack ABS
substrates upon cleaning 20W motor oil from them while the present
solvents do not.
The compounds used were as follows.
______________________________________
Example Compound
______________________________________
Comp. 44 HCFC-123
Comp. 45 HCFC-123a
Comp. 46 HCFC-141b
Ex. 44 HCFC-225CA
Ex. 45 HCFC-225CB
Ex. 46 HCFC-243CC
______________________________________
Strips of acrylonitrile-butadiene-styrene which measured
0.125".times.0.25".times.2" (0.3175 cm.times.0.635 cm.times.5.08 cm) had
coatings of 20W motor oil thereon. The strips were submerged in each of
the foregoing solvents at their boiling points for 10 minutes. One side of
the ABS used was smooth while the other side was stippled. Visual
observations were made regarding changes in the appearance of the ABS. The
results are report in Table 6 below.
TABLE 6
______________________________________
Example Result
______________________________________
Comp. 44 The solvent severely attacked the ABS.
Comp. 45 The solvent severely attacked the
ABS.
Comp. 46 The solvent removed most of the
stippling
Ex. 44 The 20W motor oil was essentially
removed from the ABS strip. The
solvent did not attack the ABS.
Ex. 45 The 20W motor oil was cleaned from
the ABS strip. The solvent did not
attack the ABS.
Ex. 46 The 20W motor oil was essentially
removed from the ABS strip. The
solvent did not attack the ABS.
______________________________________
These results indicate that HCFC-123, HCFC-123a, and HCFC-141b are
unsuitable for cleaning ABS substrates because they attack the polymeric
material. In contrast, the present solvents of Examples 44, 45, and 46 are
suitable for essentially removing 20W motor oil from ABS and they do not
attack the polymeric material.
Having described the invention in detail and by reference to preferred
embodiments thereof, it will be apparent that modifications and variations
are possible without departing from the scope of the invention defined in
the appended claims.
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