US2834737A - Foaming bleach - Google Patents

Description

United States FOAMIN G BLEACH No Drawing. Application January 15, 1957 Serial No. 634,170

4 Claims. (Cl. 252-187) This invention relates to liquid bleaching and germicidal compositions and more particularly to aqueous sodium hypochlorite solutions containing an organic agent having foaming and penetrating properties.

This application is a continuation-in-part of Serial No. 412,378, filed February 24, 1954, now abandoned.

Various organic surface active agents have been mixed with weak hypochlorite solutions but due to the tendency of the chlorine in the solution to attack the organic substance the use of these organic materials is limited to very dilute solutions. In most instances, such as for use in bleacheries, surface active agents are employed and such mixtures are not allowed to stand for very long periods of time, even in the case of weak solutions, because of the tendency'of the organic materials to decompose in the presence of the bleaching agent.

Dry hypochlorite mixtures with anionic surface active agents have been successfully employed and at least one instance has been mentioned in which dry hypochlorite compositions have been employed with a cationic surface active agent. In each instance it is necessary that the surface active agent be low in hygroscopic properties because of the recognized tendency of these substances to decompose in the presence of moisture and a strong oxidizing agent.

It was hitherto thought impossible to mix a wetting agent or a surface active agent in a relatively concentrated aqueous hypochlorite solution without decomposing the organic material and destroying the bleach even though it has long been desired to produce a household bleach in combination with organic surface active agents to give the bleach, a penetrating and foaming action. In the past, very little has been accomplished in the way of checking the undesirable odor of household bleaches and it is well known that this odor lingers on the hands of the user as well as the materials to which the bleach has been applied.

Accordingly, it is an object of this invention to provide a more pleasing household bleach containing organic surface active agents which lend a penetrating and foaming action to the bleach.

It is another object of this invention to provide a household bleach in which the characteristic bleach odor is checked so that within a short period of time after use the disagreeable odor will no longer be present on the hands of the user or the materials treated by the bleach.

It is a further object of this invention to provide a bleach having the above mentioned desirable qualities brought about by the use of a surface active agent which remains stable upon storage over extended periods of time.

My invention generally comprises a concentrated aqueous sodium hypochlorite solution and an amphoteric betaine to provide a foaming and penetrating action and to arrest the objectionable odor of the bleach. Most commercial bleaches contain about 5.25% available chlorine by weight and experiments have shown that the ice betaines may be effectively employed in solutions containing as high as 16.5% available chlorine. About 05% to 1% by weight of the betaine has been effectively employed, the quantity being limited in the lower range by the effectiveness of the betaine and in the upper range by the cost thereof. About .1% of the surface active agent in about a 5.25% sodium hypochlorite solution is preferred.

Experiments have shown that anionic and non-ionic surface active agents will salt out or decompose the bleach within two or three days, more or less. All

cationic agents were thought to be incompatible with rela tively concentrated sodium hypochlorite solutions.

However, it has now been found that the amphoteric betaines are compatible with sodium hypochlorite and.

will not salt out or destroy the bleach even after months of standing in concentrated sodium hypochlorite solutions of the type that are sold in grocery stores to the household trade.

The betaines compatible with sodium hypochlorite solutions to yield a foaming, penetrating bleach having low odor have the following structure:

i oH| ,N-o-c=o where R is a long chain alkyl group containing 10 to 16 carbon atoms. The betaines may thus be termed C- higher al'kyl-N-trirnethyl-a-betaines. Examples of C- higher alkyl-substituted betaines useful in the present invention are decyl, dodecyl (lauryl), tetradecyl (myristyl), hexadecyl (cetyl) and octadecyl (stearyl) betaines.

The following examples illustrate the invention:

Example I Gms. Aqueous sodium hypochlorite. containing 5.25%

available chlorine by weight C-decyl-N-trimethyl-a-betaine (Du Pont Product were mixed at room temperature. The resultant clear solution had very good foaming and penetrating power, was a potent bleach, as determined by using the bleach with various white fabrics during the rinsing thereof in laundering, and the characteristic hypochlorite odor was almostunnoticeable. The solution was stored for a period of nine months at room temperature in brown bottles and after that period of time the available chlorine was 5.25% by weight. The bleaching and foaming action was unchanged.

Example 11 Gms. Aqueous sodium hypochlorite containing 16.5%

available chlorine by weight 1,000 C-cetyl-N-trimethyl-a-betaine (Du Pont product storage for extended periods.

The sodium hypoehlorite useful in the preparation of solution of the present invention may be the conventional bleaching solution of the prior art. Such solutions,prepared, for example, by chlorination of aqueous caustic soda or by causticization .of bleaching powder, contain, other salts, such as sodium chloride and calcium chloride, respectively. The presence-of 'theseinactive salts does not affect the usefulness of the foaming bleach oi? the invention.

The bleaches of the present invention are clear, stable solutions. They retain their clarity and strength after products is desirable as an added sales appeal. I

It is observed therefore that the hypochlorite itself is more stable. in storage because of the addition of the betaine. It is well known that a common problem with regard to hypochlorite solutions is their instability and loss of strength on storage and any of the hypochlorite solutions referred to.- in the above examples withoutv the addition of the quaternary would, have shown an appreciable loss of available chlorine after storage under such conditions.

A bleach which is almost odorless offers agreat advantage in that the bottling thereof is greatly facilitated. A great'deal of breakage normally occurs during the high speed bottling processes; employed in most plants producing bleach. The penetrating odor of the bleach on the operators make it almost impossible for them to work under such conditions. This problem is minimized when" bottling the above described bleach.

While the invention has been described in terms of The high clarity of the certain examples, such examples are to be construed as illustrative rather than limiting. and it is intended to cover all modifications and embodiments which fall within the spirit and scope of the appended claims.

Iclaim:

l. A bleach comprising an aqueous solution of sodium hypochlorite containing from about 3% to about 16.5% available chlorine by weight and from about 0.05% to about 1% by weight of a C-higher alkyl-N-trimethyl-abetaine, said higher alkyl group containing 10 to 18 carbon atoms.

2. A bleach set forth in claim 1 wherein said bctaine is C-decyl-N-trimethyl-a-betaine.

3. A bleach set forth in claim 1 wherein saidbetaine is C-cetyl-N-trimethyl-m-betaine.

4. A bleach set forth in claim 1. wherein said sodium hypochlorite solution contains about 5.25% available chlorine by weight.

References Cited in the file of this patent UNITED STATES. PATENTS 2,129,264 Downing et al Sept. 6, 1938 2,255,057 Holt Sept. 9, 194]. 2,320,280 Kalusdial May 25, 1943 2,415,657 Riggs et al. Feb. 11, 1947 2,576,205- Apperson Nov. 27, 1951 2,702,279- Funderburk et al Feb. 15, 1955 OTHER REFERENCES Surface Active Agents, by Schwartz et al. (1949), pages 2129-22 3=, Interscience Publishers, Inc., New'York.

Claims (1)

1. A BLEACH COMPRISING AN AQUEOUS SOLUTION OF SODIUM HYPOCHLORITE CONTAINING FROM ABOUT 3% TO ABOUT 16.5% AVAILABLE CHLORINE BY WEIGHT AND FROM ABOUT 0.05% TO ABOUT 1% BY WEIGHT OF A C-HIGHER ALKYL-N-TRIMETHYL-ABETAINE, SAID HIGHER ALKYL GROUP CONTAINING 10 TO 18 CARBON ATOMS.