U.S. patent number 3,676,353 [Application Number 05/115,885] was granted by the patent office on 1972-07-11 for nonflouride laundry sour containing fumaric acid.
This patent grant is currently assigned to Basf Wyandotte Corporation. Invention is credited to John D. Ciko.
United States Patent |
3,676,353 |
Ciko |
July 11, 1972 |
NONFLOURIDE LAUNDRY SOUR CONTAINING FUMARIC ACID
Abstract
The laundering of fabrics is improved by the use of fumaric acid
as a laundry sour. Very satisfactory results are obtained by the
use of a laundry sour containing a predominant amount of fumaric
acid and a minor amount of a glassy sodium metaphosphate.
Inventors: |
Ciko; John D. (Detroit,
MI) |
Assignee: |
Basf Wyandotte Corporation
(Wyandotte, MI)
|
Family
ID: |
22363968 |
Appl.
No.: |
05/115,885 |
Filed: |
February 16, 1971 |
Current U.S.
Class: |
510/529;
252/193 |
Current CPC
Class: |
C11D
7/265 (20130101); C11D 7/16 (20130101) |
Current International
Class: |
C11D
7/22 (20060101); C11D 7/02 (20060101); C11D
7/16 (20060101); C11D 7/26 (20060101); C11d
007/08 (); C11d 007/26 (); D06l 001/16 () |
Field of
Search: |
;252/136,142,143,144,145,193 ;8/77 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
"Laundry Sours," by Dr. Foster D. Snell in Soap, Vol. 13, No. 6,
June 1937, pages 31-34. .
"Industrial Detergency," Edited by Wm. W. Niven, Jr., Reinhold
Publishing Co., N.Y., 1955, pages 65 & 66..
|
Primary Examiner: Rosdol; Leon D.
Assistant Examiner: Albrecht; Dennis L.
Claims
What is claimed is:
1. An improved laundry sour composition consisting essentially of
about 60 to about 90 percent by weight of fumaric acid, about 10 to
about 40 percent by weight of a glassy sodium metaphosphate and
from 0 to about 10 by weight of citric acid.
2. A composition according to claim 1 consisting essentially of
about 60 to about 80 percent by weight of fumaric acid, from about
10 to about 25 percent by weight of sodium hexametaphosphate and
about 5 to 10 percent by weight of citric acid.
3. A rinse water containing from about 0.02 to about 1.0 percent by
weight of the laundry sour composition of claim 1.
4. In a fabric laundering process wherein the washed fabrics are
rinsed in an aqueous solution of a laundry sour composition, the
improvement which comprises incorporating the composition of claim
1 into the aqueous rinse solution as a laundry sour.
5. The process of claim 4 wherein the temperature of the rinse
solution is held at 160 to 190.degree. F and the fabric is treated
with the rinse solution of the laundry sour for about 10 to 25
minutes, whereby reclaiming of the laundered fabric is achieved.
Description
BACKGROUND OF THE INVENTION
1. Field of the invention
This invention relates to improvements in the art of laundering
fabrics, and more particularly relates to improvements in
neutralization of the residual alkalinity and prevention of iron
stain formations in the laundered fabrics.
2. Description of the Prior Art
The ability to remove the stains, particularly iron and rust
stains, has long been recognized as a highly desirable
characteristic in a laundry sour. Historically oxalic acid and
fluoride salts have been regarded as the prime anti-rust agents for
sours by virtue of the fact that neophytes have been unable to
achieve the same degree of efficacy. Although oxalic acid and the
fluorides are quite efficient, their use in all phases of the
modern laundry industry has not been encouraged as a result of
particular aggression towards cellulosic fibers and a high degree
of toxicity. U.S. Pat. No. 2,086,867 discloses the sequestering of
iron, aluminum and copper in neutral or only slightly alkaline
solutions by the use of the sodium hexametaphosphate. This patent
further teaches that in alkaline solutions encountered in
laundering operations metaphosphate complexes resulting from the
use of sodium hexametaphosphate may be kept in solution by the use
of tartrates, oxalates or citrates. U.S. Pat. No. 2,331,396 teaches
the use of sodium acid fluoride and up to 10 weight percent of
sodium hexametaphosphate as a stabilized laundery sour. However, as
previously pointed out due to toxicity, solubility limitations
and/or cost considerations, the foregoing compositions cannot be
considered ideal laundry sours, and considerable efforts have been
expended over the years to find improved compositions.
It is, therefore, an object of this invention to provide a more
satisfactory laundry sour which is free of objectionable toxicity.
It is yet another object of this invention to provide a more
comprehensive laundry sour which goes beyond the traditional role
of simply neutralizing the excess alkalinity. These and other
objects will become readily apparent to one of skill in the art
upon reading of the following specification.
SUMMARY OF THE INVENTION
In accordance with this invention, there is provided an improvement
in the laundering of fabrics comprising the use of fumaric acid as
a laundry sour. Furthermore, a comprehensive laundry sour
composition is obtained by using a composition comprising a major
amount of fumaric acid and a minor amount of a glassy sodium
phosphate.
DESCRIPTION OF THE PREFERRED EMBODIMENT
It was surprising to find that fumaric acid, a low molecular weight
dicarboxylic acid, was an effective laundry sour in view of the
prior art which placed heavy emphasis on tri and higher carboxylic
acids or hydroxy carboxylic acids. The amount of fumaric acid
employed of course will depend upon the alkalinity of the rinse
water, but in general, satisfactory results are obtained when the
acid is added to the rinse water in amount of about 0.01 to about
0.05 percent by weight. The fumaric acid employed in this invention
can be any of the regular grades of fumaric acid normally available
ranging from the ordinary commercial grade to reagent grade. It is
of course well known that fumaric acid is an acceptable food
acidulant and hence for laundry purposes, can generally be
considered non-toxic. In contrast, maleic acid which is the
opposite sterro configuration of fumaric is toxic.
As indicated in discussing the prior art, it is conventional in
laundering operations at the time of souring the washed fabrics is
also sequester troublesome metal irons such as iron and copper so
as to give the washed fabrics a cleaner brighter look. It is well
known that iron contributes a yellow cast which is most pronounced
upon white or light colored goods. Therefore, it has been found
advantageous to incorporate in with the fumaric acid a small amount
of a glassy sodium phosphate having the generalized formula (Na
PO.sub.3) x wherein x has a value from about 3 to 22. Preferably
the phosphate is sodium metahexaphosphate wherein x = 6. Depending
upon the amount of iron concentration in the rinse water, it can
also be advantageous to add small amounts of citric acid along with
the sodium phosphate so as to prevent the precipitation out of the
complexed iron and other metal salts. As is the case with the
fumaric acid, any of the various grades of sodium phosphate and
citric acid may be employed in the compositions of this invention.
The fully formulated laundry sour of this invention will,
therefore, contain from about 60 to about 90 weight percent fumaric
acid, from about 10 to about 40 percent glassy sodium phosphate,
e.g., sodium hexametaphosphate and up to about 10 percent citric
acid. Especially desirable overall results are obtained when the
composition comprises from about 60 to about 80 percent fumaric
acid, from about 10 to about 25 percent sodium hexametaphosphate
and about 5 to 10 percent by weight of citric acid. The formulated
sour is added to the rinse water in an amount of about 0.02 to
about 1.0 percent by weight.
The fumaric acid or formulated laundry sour is added to the rinse
water fabric mixture in the customary manner and at the usual time
and temperatures as is well known in the laundry art. The actual
amount added will depend on local conditions such as alkalinity and
metal ion concentration. In addition to using the invented
composition in the normal souring operation, it will be readily
apparent to those skilled in the laundry art that the composition
can be used in a similar manner for an iron prevention measure.
While the conditions of use differ from the foregoing two
operations, the invented composition can also be used in the so
called reclaim operation of laundries wherein iron and other
material stains are removed from fabrics.
When used in the reclaim operation, most satisfactory results are
obtained with the formulated laundry sour composition of this
invention by using elevated water temperatures such as 160.degree.
to 190.degree. and treating the fabric with the composition for
about 10 to 25 minutes at a solution strength of about 0.1 to about
1.0 percent by weight. The invention is further described in the
following example:
Swatches of iron oxide stain Indian Head muslin (31/2 inch by 21/2
inch) were placed in the standard laboratory Launder-ometer Wash
Operation and treated with the indicated laundry sour composition
at a concentration of 0.5 percent for 20 minutes. Afterwards, the
swatches were removed, hand rinsed under running tap water and
dried in an oven at 110.degree.-120.degree. C. The swatches were
then evaluated with a Hunter D-40 Reflectance meter (blue) to
determine the amount of change in appearance due to the reclaiming
procedure. The procedure was then repeated with swatches which were
a blend of 65 percent polyester and 35 percent cotton. Sour A was
composed of 70 percent fumaric acid, 20 percent sodium
hexametaphosphate, and 10 percent citric acid. Sour B was a
commercial laundry sour which is a mixture of ammonium and sodium
silicofluorides. The results of the reclaimed procedures are
tabulated below in Table I.
TABLE I
.DELTA. Change in Hunter Blue Reflectance Polyester Sour
Temperature Cotton Fabric Cotton Blend
__________________________________________________________________________
A 180.degree.F 55.4 40.6 B 160.degree.F 52.7 43.7
__________________________________________________________________________
from inspection of the table, it is readily apparent that the sour
composition of this invention is equally effective as the prior art
silicofluoride salt sour, and yet the problem of toxicity has been
avoided. In a similar manner, the sours of this invention are
equally effective in the prevention of iron deposition and
redeposition in freshly laundered fabrics in addition to
neutralizing the excess alkalinity which results in normal
laundering procedures.
The foregoing example and methods have been described in the
foregoing specification for the purpose of illustration and not
limitation. Many other modifications and ramifications will
naturally suggest themselves to those skilled in the art based on
this disclosure. These are intended to be comprehended as within
the scope of this invention.
* * * * *