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Патент USA US3070644

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3,070,634
Patented Dec. 25, 1962
1
2
form and methylchloroform containing speci?ed addi
tives:
3,070,634
STABILIZATION 0F METHYLCHLOROFORM
Donald E. Hardies, and Blaine 0. Pray, Wadsworth, Ohio,
assignors, by mesne assignments, to Pittsburgh Plate
5
Glass Company
No Drawing. Filed Mar. 1, 1960, Ser. No. 12,090
2 Claims. (Cl. 260-6525)
Table
Additive Concentration,
Percent by Weight
Compo
This invention deals with methylchloroform. It espe~
cially concerns providing methylchloroform which is pro 10
sition
tetra-
hydro-
tected against decomposition, degradation and corrosive
Test Results
2-rnethyl
t-butano13-butyn
furan
2-01
action on metals.
Methylchloroform,
1,1,1-trichloroethane, is a nor
A
_
_
Failure—Pron'pt
of industrial solvent applications. It is useful for clean
ing metal articles contaminated with greases, oils and the
into
B ...... __
0.5
__________________ __
in
30
0.
their alloys with trace amounts of water present, the de
Failure~Prompt evolution
of gas; Solvent blackens
aft?r several hours.
________ __
o.
Failure—Prompt evolution
of gas; Sohent blackens
after about one hour.
It may be used as a vapor phase
degreasing solvent. In these applications, methylchloro 25
After 24 hours, only slight
corrosion; Solvent is free
from tarry matter and but
form’s corrosiveness and/or instability is a serious deter
Realization of its full potential as a vapor de
pressant depends upon minimizing its corrosive action
evolution
Do:
composition of methylchloroform is especially pro
nounced.
Methylchloroform is also a useful vapor pressure de
Failure-Prompt
of gas; Solvent blackens
into tarry mass after short
period of time.
decomposition tendencies limit its value. In the degreas
ing of light metals such as aluminum, magnesium and
rent.
tarry mass
minutes.
15
like by liquid phase degreasing. Unfortunately, its strong
pressant in aerosols.
evolution
of gas; Solvent blaokens
mally liquid chlorinated hydrocarbon useful in a variety
1.0
1.5
1.5
SliigJhtIy
yellow.
0.
upon many of the metals used in aerosol containers. For
it to be an effective vapor phase metal degreasing solvent, 30
its instability under the conditions prevailing in degreas
ing should advisedly be minimized.
It has now been discovered that methylchloroforrn may
be stabilized so as to reduce or eliminate its aforemen
In lieu of the speci?c alcohols above identi?ed, other
saturated aliphatic alcohols and other acetylenically un
saturated alcohols may be employed in conjunction with
tetrahydrofuran to provide for the stabilization of methyl
tioned limitations regarding instability and corrosiveness. 35 chloroform.
Thus, methylchloroform of enhanced‘ stability and other
Other alcohols besides the preferred, most elfective
valued properties is hereby provided. These and other
2-methyl-3-butyn-2-ol are the acetylenic alcohols (alco
bene?ts are realized by incorporating in methylchloro
hols having a triple unsaturation -——CEC——) such as pro
form tetrahydrofuran, a lower aliphatic saturated alcohol,
pargyl alcohol; Z-butyn-l-ol; 3-butyn-2-ol; 3-methyl-1
and an acetylenically unsaturated alcohol.
Relatively 40
small amounts of these materials are suitable.
pentyn-3-ol; 3-methyl-l-pentyn-3-ol; 3-ethyl-1-pentyn-3
ol; 2-rnethyl-3-hexyn-2-ol; 3,5-dimethyl-l-hexyn-3~ol; 2,5
In the preferred embodiment hereof, unusually e?ec
dimethyl - 3-hexyn-2,5~diol; 3,6-dimethyl-4-octyn-3,6-diol
tive stabilization of methylchloroform is provided by the
and like alcohols which are su?’iciently soluble in the
simultaneous presence of tertiary-butyl alcohol, 2-methyl
methylchloroforrn. Mostly, these are 3 to 12 carbon
3-butyn-2-ol and tetrahydrofuran in the methylchloro 45 acetylenic alcohols.
form. The effectiveness of a stabilizing system including
The saturated aliphatic alcohol component of this sta
these three components is apparently due to coaction
bilizing system is ideally tertiary-butyl alcohol. Never
therebetween as evidenced by experimental data.
theless, other lower molecular weight saturated alcohols,
The following example illustrates this invention and
notably those of 1 to 8 carbons including methanol,
demonstrates the unique coaction of the additives in sta 50 ethanol, propanol, isopropanol, n-butanol, tertiary-amyl
bilizing methylchloroform:
EXAMPLE
alcohol, hexanol and octanol are of value.
Usually, the concentration of tertiary-butanol or like
saturated alcohol is between 0.5 and 3.0 percent, ideally
about 1.5 percent, by weight of the methylchlo-roform.
A series of tests are conducted by a procedure in which 55 Higher or lower concentrations are not, however, pre
an aluminum strip is immersed completely in a glass
cluded. Corresponding concentrations of the acetylenic
beaker ?lled with methylchloroform. With the strip
covered by the methylchloroform, it is scratched. While
alcohol (or mixture of acetylenic alcohols) are used.
Tetrahydrofuran is employed elfectively in concentra
at room temperature of 25° C., the contents of the flask
tions of at least about 0.5 percent by weight of the meth
are observed to determine evolution of gas, formation of 60 ylchlor-oform. Ideal concentrations are from 1.0 to 3.0
dark precipitate, and discoloration of both the strip and
methylchloroform. Evolution of gas and discoloration
weight percent.
Other materials may also be included in the methyl
(both of the methylchloroform and strip) within short
chloroform such as alkyl-amino phosphates or phosphites,
periods of time indicate instability.
e.g., the reaction product of (3-methylbutyl) (2-ethyl
The following table records results with methylchloro 65 hexyl)
phosphoric acid and an amine such as dicyclo
3,079,634
3
4
hexylamine or a fatty amine such as decylamine, dodecyl
1.5 percent 2-methy1-3-butyn-2»ol, 1.5 percent tertiary
amine, hexadecylamine or octadecylamine.
butanol and from 0.5 to 3.0‘ percent tetrahydrofuran.
While the invention has been described by reference to
speci?c details of certain embodiments, it is not intended
to limit the invention to such details except insofar as
they appear in the claims.
We claim:
1. Stabilized methylchloroforrn containing 2-methy1-3
butyn-Z-ol, tertiary-bu-tanol and tetrahydrofuran.
2- Stab?ized methylqhloroform containing by weight
References Cited in the ?le of this patent
UNITED STATES PATENTS
2,371,644
2,371,645
2,603,622
2,841,625
Petering et a1 _________ __ Mar. 20, 1945
Aitchison et a1 ________ __ Mar. 20, 1945
Berger et al ___________ __ July 15, 1952
Burch et a1. ___________ __ July 1, 1958
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