US2975139A

US2975139A - Laundering method and composition therefor

Info

Publication number: US2975139A
Application number: US613385A
Authority: US
Inventors: Hugo J Kauffmann; Alfred P Mentecki; Samuel S Naistat; Hugo J Wehrfritz
Original assignee: FMC Corp
Current assignee: FMC Corp
Priority date: 1956-10-02
Filing date: 1956-10-02
Publication date: 1961-03-14
Anticipated expiration: 1978-03-14
Also published as: FR1183646A; GB819842A; BE598265Q

Description

United States Patent M LAUNDERING METHOD AND COMPOSITION THEREFOR Hugo J. Kaulimann and Alfred P. Mentecki, Bnlfalo, Samuel S. Naistat, Snyder, and Hugo J. Wehrfritz, Lancaster, N.Y., assignors to Food Machinery and Chemical Corporation, San Jose, Calif.

No Drawing. Filed Oct. 2, 1956, Ser. No. 613,385

2 Claims. (Cl. 252-99) The present invention relates to an improved method of laundering and to a shelf stable laundering composition therefor.

The type of detergent presently employed in laundering consists almost universally of the so-called synthetic detergent type wherein the main surface active agent is an alkyl aryl sulfonate.

Almost without exception, the synthetic type of laundering powder or liquid contains additional water softeners and so-called builders, carboxy methyl cellulose, all of which aid in controlling the foaming qualities of the product, in controlling the removal of soil from the goods to be laundered, and in preventing redeposition of the soil uniformly on the goods once the soil is removed therefrom.

Attempts have been made to incorporate bleaching material or agents in the laundering bath, either as a separate ingredient or as an ingredient integral with the detergent composition. In general, substantially all known active bleaching agents have been employed as adjuncts with the synthetic detergents. These attempts have not been too successful. This failure is generally due to the fact that the normal class of bleaching agents are either not too stable with time, and tend to decompose, as for instance the hypochlorites, or are not particularly eifective under normal laundering conditions, as for instance the perborates.

It is an object of the present invention to provide a method of laundering fabrics and goods under conditions where the soluble perborates may be effectively employed as bleaching adjuncts with synthetic detergents.

It is another object of the invention to provide a synthetic detergent laundering composition which is shelf stable, that is, retains its bleaching activity with time.

In accordance with the broad concepts of the present invention, the usual synthetic detergent is compounded with soluble perborate, preferably sodium perborate, in any suitable amount. In general, the amount of sodium perborate compounded with the detergent will be from about 5 to about 30% by weight. In the use of a formulation of this type at usual laundering temperatures, that is, temperatures from about 100 F. to 140 F. more or less, the sodium perborate releases its active oxygen for bleaching purposes at a rate slower than the usual laundering time, and therefore, in accordance with the present invention, a catalyst is introduced for speeding up this particular reaction. The catalyst is present in extremely small amounts in the final laundering solution and may be present and effective in quantities so little as 0.25 to 5 parts per million of solution.

Under these circumstances, at the normal laundering temperatures employed and specified above, the sodium perborate, under the influence of the catalyst, decomposes and provides eifective bleaching action for the purpose of whitening white goods, brightening colored goods, and removing the usual stains encountered in laundering operations such as vegetable juice, ink,

2,975,139 Patented Mar. 14, 1961 ICC chlorophyl (grass stains), chocolate, coffee, tea, and lipstick.

The catalyst preferred for accelerating the decomposition of the sodium perborate and liberating the active oxygen therefrom is a copper-containing soluble salt and is useful by reason of the fact that it may be used in such small quantities and any deposition of copper upon the goods is so slight as not to be subsequently noticeable.

A typical formulation of a detergent composition of the present invention would include:

Parts by weight Alkyl aryl sulfonate 140 Sodium tripolyphosphate 140 Tetrasodium pyrophosphate 60 Carboxymethyl cellulose (CMC) 4 Sodium metasilicate 22.8 Sodium perborate tetrahydrate 64 Copper sulfate pentahydrate 2.84

The above formulation, when used in the proportion of 1 cupful (34 ozs.) per 10 to 18 gallons of water (the normal capacity of a usual domestic washer) will provide, at the latter volume, per million parts of wash solution, approximately 40 parts of active oxygen by weight, a quantity sufiicient to produce a good bleaching action on six to eight pounds of goods, the capacity of the average Washing load. In general the amount of perborate should be sufficient to furnish 20 to 60 parts per million of bath.

The detergent formula alone, without perborate, when used to prepare a laundering solution, produced on ordinary bleached sheeting when laundered at 140 F., a white having a reflectance of 80.4, as determined by a Hunter reflectometer. The same sheeting, when laundered under the same conditions of temperature, time, and the same amount of detergent, plus the addition of the quantity of the perborate specified above, approximately 14.5% based on the total weight of detergent, produced a laundered sheet having a reflectance of 83.5.

An additional piece of the same goods laundered under the same conditions of temperature, time, and the same amount of detergent, but contained in addition to the perborate specified, approximately 7% by weight copper sulfate pentahydrate, produced a white of 84.7.

At lower laundering temperature, the effect of the perborate is less pronounced and the effect of perborate with catalyst is more pronounced and the action is of especial value in the completion of laundering and stain removal.

Another sample of soiled goods made of unbleached broadcloth was laundered with a laundering formula similar to that given above, at a laundering temperature of F., a temperature more nearly identical with that existent in a normal domestic laundering process. The reflectance of the goods initially employed was 67.8 as determined on the Hunter refiectometer. The goods, after being subjected to this laundering procedure with a standard laundering detergent, possessed a reflectance of 69.7.

Another sample of the same soiled broadcloth was laundered at 120 F. with the same laundering composition, to which was added about 15% sodium perborate tetrahydrate equivalent to 40 parts active oxygen in the wash solution. There was only a slight increase in brightness of the goods and the active oxygen content of the laundering solution was substantially the same at the end of the laundering operation as at the beginning thereof. Thus the active oxygen content was 41.6 parts per million of solution at the start of the laundering procedure and had dropped to only 39.2 after one hour. The reflectance of the laundered goods was 72.3.

Another sample of the soiled broadcloth was laundered at 120 C. with the detergent-perborate composition to which was added sufiicient soluble copper salt, that is copper sulfate, to produce in the laundering solution 1 part dissolved copper per million parts of solution. At the beginning of the laundering operation the active oxygen content was 34.4 parts per million which, after one hour, had dropped to 22.4 parts per million. The goods after washing and rinsing in the usual way, and as had been done in the previous operations, possessed a reflectance of 77.3. With two parts per million of copper at 120 F. in another batch on the same goods, the active oxygen content dropped to 8.8 parts per million from an initial concentration of 22.4 parts per million.

In general, a lower laundering temperature tolerates a greater amount of dissolved copper. In general, the copper content should be from about A part per million to not more than 10 parts per million, with a preferred concentration of from 2 to 4 parts per million, a concentration best adapted for use in domestic laundering procedures.

It has been found, in accordance with the present invention, that even though copper contamination is thought of as a vigorous catalyst of decomposition for persalts, such as sodium perborate, dry mixes of synthetic detergents of the alkyl aryl sulfonate type and containing from 5 to 40% of sodium perborate tetrahydrate are not readily decomposed on storage, and intimate admixtures may contain the detergent, the bleachant-namely a water soluble perborateand a water soluble copper salt and possess excellent shelf stability.

A composition containing 400 parts of the usual type of detergent, 64 parts sodium perborate tetrahydrate and 2.84 parts copper sulfate pentahydrate, possessed an active oxygen content initially equivalent to 1.42% as determined by titration with permanganate. After standing six months at an average temperature of approximately 25 C., the active oxygen content was determined as 1.37%, a figure within the experimental error of the determination.

It will be understood that although sodium perborate has been illustrated as the perborate to be employed by reason of its availability, any water soluble perborate may be employed in the same fashion as the brightening additive or bleachant for the detergent composition.

It will be further understood that although copper sulfate has been illustrated as the catalytic source, any soluble copper salt will serve, as for instance highly soluble salts such as the nitrate or acetate or slightly soluble salts such as the phosphate, among others. In any case, the dissolved copper compound is the catalyst and the salt chosen should provide a copper concentration in the laundering solution of from about 0.5 to parts per million.

Although it has been indicated that the tetrahydrate of sodium perborate is incorporated, it will be understood that other perborates may be employed, the

amounts of which added to the detergent composition being an amount sutficient to produce 0.8% to about 2.4% active oxygen.

In the example given above, a compound detergent and oxidant of 4 oz. of such composition in 15 gallons of water will produce a concentration of copper of approximately 3 parts per million of the laundering solution, while the soluble copper salt should be present in dry mix in an amount sufficient to produce from 0.04% to 0.4% copper.

What is claimed is:

1. A stable dry-mixed detergent composition comprising, an alkyl aryl sulfonate synthetic detergent, a water-soluble perborate, and a water-soluble inorganic copper salt, wherein all the components of said composition are admixed and in intimate contact with each other, the perborate being present in an amount sufficient to produce an active oxygen content in the range of 0.8% to 2.4% by weight, and the inorganic copper salt being present in an amount sufficient to produce a copper content within the range of 0.04% to 0.4% by weight and being substantially free of surface coatings.

2. A method of laundering which comprises heating the goods to be laundered in an aqueous bath at a temperature between about F. to F. until the laundering is completed, said aqueous bath containing an alkyl aryl sulfonate synthetic detergent, a watersoluble perborate, and a water-soluble inorganic copper salt, the amount of perborate being sufficient to produce an active oxygen content in the composition of from 0.8% to 2.4% by weight, the amount of copper salt being sufiicient to produce a copper concentration in the range of 0.5 part per million to 10 parts per million by weight of the laundering solution, and wherein said synthetic detergent, said water-soluble perborate, and said water-soluble inorganic copper salt are introduced into said aqueous bath in the form of a dry-mixed composition wherein all the components of said composition are admixed and in intimate contact with each other, and said inorganic copper salt being substantially free of surface coatings.

References Cited in the file of this patent UNITED STATES PATENTS 2,477,631 Levy et a1 Aug. 2, 1949 2,498,344 Rider et a1 Feb. 21, 1950 2,576,205 Apperson Nov. 27, 1951 2,706,178 Young Apr. 12, 1955 2,763,618 Hendrix Sept. 18, 1956 FOREIGN PATENTS 188,811 Great Britain Nov. 23, 1922 291,743 Great Britain Sept. 30, 1929 310,030 Great Britain June 5, 1930 OTHER REFERENCES Dahlstrom: Chemical Abstracts, vol. 20, pp. 3087, 3088 (1926).

Claims

1. A STABLE DRY-MIXED DETERGENT COMPOSITION COMPRISING, AN ALKYL ARYL SULFONATE SYNTHETIC DETERGENT, A WATER-SOLUBLE PERBORATE, AND A WATER-SOLUBLE INORGANIC COPPER SALT, WHEREIN ALL THE COMPONENTS OF SAID COMPOSITION ARE ADMIXED AND IN INTIMATE CONTACT WITH EACH OTHER, THE PREBORATE BEING PRESENT IN AN AMOUNT SUFFICIENT TO PRODUCE AN ACTIVE OXYGEN CONTENT IN THE RANGE OF 0.8% TO 2.4% BY WEIGHT, AND THE INORGANIC COPPER SALT BEING PRESENT IN AN AMOUNT SUFFICIENT TO PRODUCE A COPPER CONTENT WITHIN THE RANGE OF 0.04% TO 0.4% BY WEIGHT AND BEING SUBSTANTIALLY FREE OF SURFACE COATING.