Note: Descriptions are shown in the official language in which they were submitted.
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METHOD AND COMPOSITION FOR REDUCED WATER DAMAGE
LAUNDRY CARE
This invention relates to the use of certain solvents, particularly
organically-
based solvents, in a method for laundering clothes or fabrics so that the
process provides
the feature of reducing the damage done to fibers in the cloth caused by
water. Further, a
composition is provided to use in the method featured. Finally, there is
provided a means
for solvent selection according to which a candidate solvent for use in the
composition and
the laundry method can be selected.
Zo Numerous patents and publications, too many to cite herein, have dealt with
the
laundry process, but usually from the standpoint of cleaning. The focus of
this invention is
the reduction of water damage to clothing and fabric which is washed in the
normal wash
cycle of commercial or home laundry machines. Some fabrics and clothing are
shrunk
beyond their intended use by water if, inadvertently, they are included in an
aqueous
15 laundry process. Such clothing and fabric can only be adequately cleaned by
the solvent
based dry-cleaning process. However, such a process can be expensive and is
not
available for home use. It would therefore be quite an advantage to have a
home laundry
process that could be useful to clean clothing and fabrics subject to water
damage, and
particularly shrinkage, in a cost-effective, time effective process with
reduced water
2o damage. The present invention has the feature that it will reduce water
damage, especially
shrinkage as well as wrinkling, dye fading, dye transfer, loss of sizing,
pilling, felting, fiber
weakening and relaxation. While a reduction of any one of these is considered
advantageous, reducing the shrinkage and pilling of wool and the shrinkage and
spotting on
silk and rayon are major advantages.
The features of the invention are provided in a method of laundering a cloth
article in
an aqueous admixture so that water damage is avoided by contacting the cloth
article in the
presence of water with a solvent having a competing adsorption with water on
the cloth
article. Another aspect of this invention provides an aqueous laundry
composition for
3 o reduced water damage to a laundered cloth article which comprises an
adsorbent amount
of a least one solvent or blend of solvents which has competing adsorbency
with water on
the cloth article. In a still further aspect of this invention, there is
provided a method of
determining suitability of a solvent for use in a reduced water damage laundry
composition
and method of laundering a cloth article which comprises the steps of
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A) measuring the surface energy of a fiber to be laundered using the Hansen
total
solubility parameters and finding the radius of interaction of said fiber;
B) determining the Hansen total solubility parameters and radius of
interaction of a
candidate solvent;
C) determining the Hansen total solubility parameters and radius of
interaction of water;
D) comparing the Hansen total solubility parameters and radius of interaction
of said
solvent with that of said fiber so that a sphere generated by the radius of
interaction
of the solvent intersects the sphere generated by the radius of interaction of
the fiber
Zo to obtain a combined fiber/solvent relative difference in the two radii;
E) comparing the Hansen total solubility parameters and radius of interaction
of said
water with that of said fiber so that a sphere generated by the radius of
interaction of
water intersects the sphere generated by the radius of interaction of the
fiber to
obtain a combined fiber/water relative difference in the two radii; and
i5 F) comparing the result of said step D with the result of said step E, such
that an
acceptable solvent for said reduced water damage laundry composition has a
combined fiber/solvent relative difference 1.5 times or less than the combined
fiber/water relative difference.
2o The method for laundering clothing or fabrics according to the present
invention
protects the fibers in the cloth by preferentially wetting the cloth fibers.
However, the
wetting takes place on the fiber surface and, thus, prevents the water from
contacting and
absorbing into the fiber causing water damage. As used in this invention the
term water
damage refers to shrinkage, wrinkling, dye fading, dye transfer, loss of
sizing, pilling, felting,
2s fiber weakening and fiber relaxation. However, many of these types of
damage require
repeated washing to manifest the damage. In contrast, shrinkage can be seen in
only one
wash cycle and many of the remaining water damage effects will be manifest in
the same
cloth after several washings. Therefore, shrinkage water damage is the most
important and
immediate type of damage. It is also easily measured by standard laboratory
tests which
3 o correlate well to effects in actual usage.
Without intending to limit the invention to any theory of operation or
mechanism of
action, it is believed that by preferentially adsorbing on the surface of the
cloth fiber a
solvent selected for such characteristics, the absorbency of water into the
fiber is hindered
and, thus, damage caused by water is decreased. This feature is obtained by
the method
35 of laundering a cloth article in an aqueous admixture whereby water damage
to the cloth
CA 02369435 2001-10-03
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article is decreased compared to that caused by laundering in water alone, the
method
comprising contacting the cloth article with a solvent having a competing
adsorption on the
cloth article and in the presence of water. Adsorption means contact and
adhesion of a thin
layer of molecules to the surface of a solid body or liquid. Absorption, in
contrast, connotes
the liquid taking into the bulk of the cloth fiber.
The solvent used in this invention can be selected from the group consisting
of
aliphatic alcohol, alkylene glycol, alkylene glycol ether, a weak acid or the
ester or
anhydride of a weak acid, alkylene amine, alkanolamine and aromatic alcohol.
Typical of
aliphatic alcohols are lower alkyl alcohols such as methanol, ethanol,
propanol; unsaturated
Zo alcohols, such as, allyl alcohol; cyclic aliphatic alcohols, such as,
furfuryl alcohol; and aralkyl
alcohols, such as benzyl alcohol. Typical of alkylene glycols are the group
consisting of
ethylene glycol, propylene glycol, diethylene glycol and triethylene glycol.
Non-limiting
examples of alkylene glycol ethers are selected from the group consisting of
ethylene glycol
methyl ether, ethylene glycol ethyl ether, butylene glycol methyl ether,
diethylene glycol
is ethyl ether, diethylene glycol methyl ether, propylene glycol phenyl ether
and propylene
glycol methyl ether. Typical of the weak acids, esters or anhydrides are those
selected from
the group consisting of formic acid, acetic acid, lactic acid, acetic
anhydride, methyl lactate,
ethyl lactate, propyl lactate, butyl lactate and glycol ether acetate. The
typical examples of
alkylene amines useful in this invention are selected from the group
consisting of
2 o ethylenediamine and diethylenetriamine. A preferred alkanolamine is
monoethanolamine.
Typical of useful aromatic alcohols are those selected from the group
consisting of phenol,
cresol and resorcinol.
The solvent is contacted with the cloth article in an amount sufficient to
reduce or
decrease water damage. Because of the different solubility parameters of
various fabrics
2s and fibers and the different solvents involved the amount of solvent can be
greatly varied.
In addition, the temperature of laundering, the amount of agitation and the
overall amount of
water employed can influence the amount of solvent necessary to reduce or
decrease water
damage in the method of this invention. In general, it has been found that
from about 0.1 to
about 15 percent by weight of solvent based on the total weight of the aqueous
wash
3 o solution or liquid can be used. Preferably, from 1 to about 10 percent by
weight of solvent
is used, with from about 3 to about 5 percent by weight being most preferred
amounts of
solvent useful in this invention.
The method of laundering contemplated by the present invention does not rely
on
any particular type of laundry apparatus and any typical commercial or
household washing
3 s machine can be usefully employed. Of course, cleaning, while important, is
not the
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emphasis of the present invention. Other laundry additives can be employed as
are
typically useful in laundry operations for cleaning. As is common in such wash
applications,
the water and solvent are usually combined prior to addition of cloth.
Alternatively, the
wash liquor, including the solvent can be applied to the cloth in the form of
a spray, foam,
mist, vapor, immersion, absorbent transfer or by other means. Once applied,
mechanical
action is used to wash the cloth, fabric, fiber or clothing. After thorough
agitation the bulk of
the liquid and soil are extracted from the cloth. An additional bulk wash step
with the
aqueous wash liquor can be carried out and then one or more rinse steps can be
employed.
The cloth is then dried according to conventional practice, such as by tumble,
microwave,
Zo convection, reduced pressure, air hang, absorbent or other means of drying.
In a still further aspect of this invention, there is provided an aqueous
laundry
composition which provides reduced water damage to a laundered cloth article
and which
comprises an adsorbent amount of at least one solvent or blend of solvents
which has
competing absorbency with water on the cloth article, clothing, fabric or
fiber to be
is laundered. More particularly, the composition of this invention is
described in which the
solvent has competing adsorption on the article in relation to water and is
non-absorbent on
the cloth, clothing, fabric or fiber to be laundered. One of the methods which
is useful to
determine whether a solvent can be employed in the method and composition of
this
invention takes advantage of the Hansen total solubility parameters, the
radius of
2 o interaction and the relative distance of a sphere generated by the radius
of interaction
calculated in accord with certain equations derived by Hansen. These
parameters are used
to determine whether a solvent will compete with water to adsorb on the fiber
surface,
preventing contact with water and, therefore, reducing water damage to the
fiber, fabric or
cloth. The Hansen solubility parameters are discussed in Chapter 4 of
Industrial Solvents
2s Handbook (by Wesley Archer, Marcel Dekker, Inc. publisher), (1996),pages 35-
56, which
are incorporated by reference as if fully set forth, with respect to the
solubility of solvents in
resins. Dr. Wesley J. Archer applied the Hansen solubility parameter theory in
reformulating
solvent-based coatings in an article in American Paint & Coatings Journal,
March 2, 1992,
pages 38-45, which is incorporated herein by reference as if fully set forth.
These articles
3 o form the basis for a further aspect of the invention which is a method of
determining a
suitable solvent for use in a reduced water damage laundry composition which
comprises
the steps of (A) measuring the surface energy of a fiber to be laundered using
the Hansen
total solubility parameters and finding the radius of interaction of the
fiber; (B) determining
or obtaining the Hansen total solubility parameters and radius of interaction
of a candidate
3 s solvent; (C) determining or obtaining the Hansen total solubility
parameters and radius of
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interaction of water; (D) comparing the Hansen total solubility parameters and
radius of
interaction of the candidate solvent with that of the fiber so that a sphere
generated by the
radius of interaction of the fiber intersects with a sphere generated by the
radius of
interaction of the solvent to obtain a combined fiber solvent relative
difference in the two
radii of interaction; (E) comparing the Hansen total solubility parameters and
radius of
interaction of water with those of the fiber so that a sphere generated by the
radius of
interaction of water intersects the sphere generated by the radius of
interaction of the fiber
to obtain a combined fiber/water relative difference in the two radii of
interaction; and (F)
comparing the result of step (D) with the result of step (E) such that an
acceptable solvent
1 o for the reduced water damage laundry composition of this invention has a
combined
fiber/solvent relative difference 1.5 times or less than the combined
fiber/water relative
difference. Also, the candidate solvent should have less absorbency than water
so as not
to cause fiber damage itself from absorption in the fiber.
Having set forth the general description of the invention, it is now desired
to set forth
the best mode of carrying out the present invention with respect to the
following Examples
of the invention in comparison to damage caused by water or by water and a
popular
standard laundry detergent.
EXAMPLES
2 o Cloth fiber damage can be demonstrated as dimensional stability.
Dimensional stability can
be reported as the percent shrinkage of a cloth after washing treatment.
Square cloth
pieces, approximately 30 cm on each side were marked with a square pattern
approximately 25 cm each side with a Laundry Sharpie marker. The cloth pieces
were then
washed in a laboratory scale horizontal axis laundry machine. The machine was
charged
with two liters of wash liquor, followed by the test cloth. The cloth was
washed for three
minutes at 200 rpm tumble agitation with tumble direction reversals every 30
seconds. The
wash liquor was drained and then extracted from the cloth with an 1800 rpm
spin cycle for
one minute. Two liters of rinse water was added and the cloth again agitated
at 200 rpm for
one minute. The rinse water was drained and then extracted from the cloth with
an 1800
3 o rpm spin cycle for one minute. Air-dry the test cloth. Measure the test
pattern dimensions,
then iron the cloth with a dry iron at the recommended temperature setting,
and re-measure
the test pattern. Shrinkage was reported as average percent difference from
the
dimensions of the unwashed and washed test cloth. For comparison wash data for
a pure
solvent dipropylene glycol n-butyl ether without a water rinse was included.
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Acetate
Wash Li quor % Shrinkage
Iweiqht ercent) (average)
p
s 100% Water 2.6%
95.4% Water 4.4% Tide 2.5%
95% Water 5% Methanol 1.7%
95% Water 5% diethylene glycol 1.2%
100% dipropylene glycol n-butyl 0.0%
ether
to
Silk
Wash Liquor % Shrinkage
(weight percentl (average)
15 100% Water 4.0%
95.4% Water 4.4% Tide 4.4%
95% Water 5% n-methyl pyrrolidone 2.1
100% dipropylene glycol n-butyl ether 0.1
2 o Rayon (not ironed)
Wash Liquor % Shrinkage
(weight percent) (average)
100% Water 10.0%
2s 95.4% Water 4.4% Tide 9.8%
95% Water 5% diethylenetriamine 4.9%
100% dipropylene glycol n-butyl ether 0.2%
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Wool
Wash Liquor % Shrinkage
(weiaht percent) (average)
s 100% Water 5.2%
95.4% Water 4.4% Tide 5.2%
95% Water 5% diethylenetriamine 3.9%
100% dipropylene glycol n-butyl 0.1
ether
Zo From the above Examples it is clear that shrinkage is reduced when a
solvent is used
according to the present invention in an aqueous laundry composition. The
invention can
also be seen to include the method in which the solvent retards the adsorption
and
absorption of water on the cloth article or fiber by the solvent itself
adsorbing on the fiber or
cloth article preferentially. A still further aspect of the invention involves
the solvent being
15 defined as having competing adsorption on the cloth article in relation to
water and the
solvent being non-absorbent on the fiber or cloth article. More preferably,
the solvent is
selected from those having a radius of interaction with the fiber or cloth
article which is
about 1.5 times or less than the radius of interaction of water with the fiber
or cloth article,
preferably, the radius of interaction is 1.0 times or less than the radius of
interaction of water
2 o with the fiber or cloth article.
