US 2856330 A
Description (OCR text may contain errors)
United States Patent METHOD OF TREATING COTTON FABRICS Harold N. Vagenius, Chicago, Ill.
No Drawing. Application Novemberfitl, 1954 Serial No. 467,658
4 Claims. (Cl. 167- 84) This inventionrelates to methods of treating cotton fabrics for preventing or delaying the development of unpleasant odors and/or a rise in pH value when the treated fabrics are exposed to or impregnated with body secretions such as perspiration or urine. The methods of this invention are particularly applicable to the treatment of diapers for the indicated purpose.
The methods of this ivention involve dipping or submerging cotton fabrics in dilute water solutions of copper salts. However, such treatment of cotton fabrics ordinarily or often causes the fabrics to be tinted green, especially in the presence of small amounts of colloidal materials such as soaps, gums, starches, proteins such as albumen or casein and other colloidal material used in washing or treating fabrics and apt to remain in the fabrics after Washing or treatment therewith. Further, dipping or submerging cotton fabrics in dilute water solutions of copper salts often render the fabrics water repellent.
It is, therefore, an object of the present invention to provide methods for treating cotton fabrics with dilute water solutions of copper salts without tinting the fabrics green or rendering the fabrics water repellent, even when the fabrics or the dipping solution of the copper salts contain colloidal materials such as soap.
According to the present invention, cotton fabrics are immersed in water solutions of a water soluble copper salt such as copper sulfate, chloride, acetate or nitrate. From about 0.05 to about 1 milligram molecules (an amount in milligrams numerically equal to the molecular weight) of copper salt are used for each 60 grams of cotton fabric. This amount of copper salt is dissolved in from 100 cc. to 1000 cc. or more of water. Further, from about 2 to about 10 milligram molecules of disodium dihydrogcn pyrophosphate are added to the solution for each milligram molecule of copper salt. dipping solution is kept acid, preferably at a pH of from about 3.0 to 3.5 to about 5 or 6. The time of immersion may be from 1 or 2 minutes up to or minutes or longer, but is not critical. The immersion may be carried out at room temperature or at elevated temperatures for instance 120 F., or 140 F. or 160 F.
The above mentioned pH range is most suitably maintained by adding to the dipping solution appropriate amounts of acidic substances such as zinc or magnesium silicofluoride, acetic acid, lactic acid, hydrochloric acid, sulfuric acid and the like. In place of the disodium dihydrogen pyrophosphate, equivalent amounts of tetrasodium pyrophosphate may be used, but then an additional amount of an acidic substance is added to neutralize one half of the sodium content of the tetrasodium pyrophosphate. In place of the sodium pyrophosphate, other alkali metal pyrophosphates may be used, such as the corresponding potassium pyrophosphates.
For convenience in making up the dipping solution, mixtures may be prepared comprising a finely divided copper salt and finely divided disodium dihydrogen pyrophosphate in a ratio of one molecule of copper salt to two Also, the pH of the to 10 molecules of said pyrophospnate. To insure proper acidity of the dipping solution, even in the presence of soaps, such mixtures may additionally comprise from one-half to two or more molecules of zinc or magnesium silicofluoride or equivalent acidic buffers for each molecule of said copper salt.
When cotton fabrics are treated as described in the preceding paragraph, then rinsedwith water and dried, the fabrics are not rendered water repellent, nor are the fabrics tinted green, even when the fabrics (or the dipping solutions) contain even fairly large amounts of colloidal materials such as soaps, fats, oils, proteins such as albumen or casein, dirt or soil and the like. Further, cotton fabrics so treated contain copper substantively fixed thereon, Which copper is not removed by wetting or rinsing with water or expo-sure to body secretions such as perspiration or urine. Further, fabrics so treated do not develop unpleasant odors and/ or a rise in pH value and/ or formation of ammonia when the treated fabrics are exposed to or impregnated with body secretions such as perspiration and urine.
Examples of treatments of 60 gram cotton diapers according to the present invention are given hereinbelow.
For each of these examples, one 60 gram cotton diaper was first wetted with 150 to 180 cc. water having .2 gram of ordinary soap dissolved therein, thereafter immersed for from three to ten minutes in a copper salt solution containing disodium dihydrogen pyrophosphate, then removed from the copper salt solution, squeezed thoroughly, rinsed with water and dried. The copper salts employed were the sulfate, chloride, acetate and nitrate. The pH was adjusted downward-1y with an appropriate amount of zinc silicofluoride. The exact amounts of copper salts, pyrophosphate, water and the pH are tabulated as follows:
i Milligram i i Milligram Example No. Copper Molecules Water, Molecules pH Salt of copper cc. of pyrosalt phosphate Sulfate. 0.05 250 1 5. 0 0.1 250 .2 4. 5 0.1 .3 4. 5 0.1 250 .4 3. 5 0. .3 350 2. 0 3. 5 l. 0 450 5. 0 3. 5 1. 5 550 10.0 3. 5 0.1 250 0.3 3. 5 0.] 250 0.3 3. 5 10 Nitrate... 0.1 250 0.3 3. 5
An untreated diaper and each one of diapers Numbers 1 through 10 of the above table was impregnated with cc. urine and placed in a polyethylene bag, which was kept at room temperature for sixdays. The control (untreated) diaper developed an unpleasant sour odor within 24 hours followed shortly thereafter by a rise in pH and generation of ammonia. in the case of diapers of Examples 1 through 10, such odor and rise in pH value did not take place before four or five days, and generation of ammonia did not occur at all.
Many details may be varied without departing from the principles of this invention. It is therefore not my intention to limit the patent granted on this invention otherwise than necessitated by the scope of the appended claims.
1. A method of treating cotton fabrics which comprises immersing said fabrics in a dilute acidic aqueous solution of a water soluble copper salt selected from the group consisting of the sulfate, chloride, nitrate and acetate, said solution containing, for each 60 grams of fabric, from about to about 1000 cc. of Water, from about 0.05 to about 1 milligram molecules of a soluble copper salt, and from about 2 to about 10 milligram molecules of a di-alkali metal dihydrogen pyrophosphate for each milligram molecule of said copper salt said solution being maintained at a pH of from about 3 to about 6.
2. A method according to claim 1 in which said pyrophosphate is a sodium pyrophosphate.
3. A method according to claim 1 in which said copper salt is copper sulfate.
4. As a new composition of matter, a mixture comprising a water soluble copper salt selected from the group consisting of the sulfate, chloride, nitrate and acetate and disodium dihydrogen pyrophosphate in a ratio of one molecule of said copper salt to from two to ten molecules of said pyrophosphate.
References Cited in the file of this patent UNITED STATES PATENTS 22,362 Glynn Dec. 21, 1858 43,233 Stacey June 21, 1864 152,903 Gender July 14, 1874 1,903,041 Hall et a1. Mar. 28, 1933 1,960,627 Finlayson May 29, 1934 2,086,867 Hall July 13, 1937 2,241,580 Bishop May 13, 1941 2,580,286 Dorsett Dec. 25, 1951 2,643,969 Mahon June 30, 1953 FOREIGN PATENTS 453,348 France Apr. 2, 1913 OTHER REFERENCES 15 and Eng. Chem., April 1941, pp. 538-545.
Fullerton: Cotton Duck and Canvas, Rot-proofing, J. Text. Inst, 1942, p. A321.
Textile Colorist, January 1943, p. 30.
Goodman: Cosmetic Dermatology, McGraw Hil 20 Book Co., 1936, p. 45, entry Cupric Sulfas.