US2903430A - Oxidizing and optical bleach - Google Patents

Description

jaJQ HLE LitLi'i -Jg OXIDIZING AND OPTICAL BLEACH Caroline Butler, South Plainfield, NJ., assignor to American Cyanamid Company, New York, N.Y., a corporation of Maine No Drawing. Application April 27, 1954 Serial No. 426,052

3 Claims. (Cl. 252-99) The present invention is concerned with the bleaching of fibrous materials. Still more particularly, it is concerned with bleaching compositions for whitening natural protein and synthetic fibrous materials. Still more particularly, it is concerned with perborate bleaching compositions having incorporated therein an organic fluorescent compound as an optical bleaching agent.

It is well known that white textile materials such as silk, wool, nylon and the like tend to develop a yellowish cast over a period of time, particularly after repeated washing and/ or exposure to sunlight. To counteract this color deterioration, it is customary to add to detergent compositions used for laundering such fibrous materials any of various types of bleaching compositions. Such bleaching compositions comprise any of variously known oxidizing compounds. One such type of bleaching composition which has found wide use in both commercial and domestic laundering practice contains sodium perborate as the oxidizing agent. Admixed with the perborate may be various compounds such as trisodium phosphate, sodium tripolyphosphate, sodium sulphate, sodium chloride, sodium carbonate and the like, each of which exerts certain beneficial effects on the bleaching bath. Although the oxidizing agent of such compositions bleaches or whitens the treated material, the whitening efl ect obtained is limited and in many instances is not sufiicient to restore the original brightness and white appearance of the material.

It has also been proposed to eliminate the yellowish cast of such textile materials by the use of certain classes of organic substances which can be applied from solution to the material and which, by fluorescing blue thereon in daylight, appear to restore the original white color. It has also been proposed to combine such organic fluorescent materials with chemical bleaching agents so as to obtain the combined elfect of chemical bleaching and optical bleaching. To be so employed, however, an organic fluorescent material must be compatible with the alkaline bleach composition.

One of the most useful fluorescent organic compounds for whitening natural protein and synthetic fibrous materials is 4-methyl-7-diethylaminocoumarin. This compound, however, is not resistant to the action of sodium perborate and/or the other alkali ingredients found in a conventional perborate bleaching composition. Soon after mixing of this compound with the perborate bleach composition, a very objectionable odor develops and becomes progressively worse on standing or on exposure to elevated temperatures. This in itself is suflicient to make the composition completely unsalable.

There has remained, therefore, a demand for bleaching compositions comprising both a chemical bleaching agent and an optical bleaching agent for use in both commercial and domestic laundering of natural protein and synthetic fibrous materials. Such a bleaching composition should be stable and not develop objectionable odors during extended periods of storage or on exposure to elevated temperatures. It should provide a whitening 2,903,430 Patented Sept. 8, 1959 and brightening efiect to the treated material which is superior to the effect obtained by either alone. Such a composition, moreover, should be capable of providing this whitening and brightening effect to various synthetic fibrous materials such as nylon and the like without danger of physical damage.

It is therefore the primary object of the present invention to provide a new bleaching composition meeting this demand. This object has been fulfilled to a surprisingly successful degree. It has now been found that a bleaching composition comprislng a perborate bleaching composition as a chemical bleach and 4-methyl-7-dimethylaminw coumarin overcomes to a striking degree the various drawbacks noted above with respect to previous chemical bleaching compositions having incorporated therein an organic fluorescent compound.

What is completely unexpected in view of the past history of the use of the diethyl homologue of the optical bleach of this composition is the complete stability of the composition of this invention during periods of extended storage or on exposure to elevated temperatures. Whereas a perborate composition comprising 4-methyl-7-diethylaminocoumarin develops an objectionable odor after mixing, the composition of this invention is surprisingly free of odor. Nor does the optical bleach of this composition tend to lose its brightening effect as do the diethyl homologue and other various coumarin derivatives.

The amount of 4-methyl-7-dimethylaminocoumarin employed may be quite widely varied. In general, however, as little as 0.01% by weight of the perborate component will provide an effective Whitening of the material treated. While as much as 2% of the fluorescent organic compound may be employed, such large amounts are usually unnecessary and provide little if any additional brightening eliect. In most cases, amounts ranging from about 0.01% to about 1.0% will suflice to give the maximum optical brightening effect.

The following examples will further demonstrate the invention. These examples are intended to be illustrative only and not by way of limitation. All parts are by weight unless otherwise noted.

Example 1 One part of 4-methyl-7-dimethylaminocoumarin and 2000 parts of a commercial bleach containing about 30% sodium perborate, 60% sodium sulfate and 6% Water were dry blended. The resulting composition was placed in an enclosed container and exposed for one week to room temperature. On opening the container there was no objectionable odor noted.

Example 2 The procedure of Example 1 was repeated substituting 4-methyl-7-diethylaminocoumarin for the dimethyl homologue thereof. After storage for a week under similar conditions the composition had a noticeably repulsive odor.

Example 3 When the compositions of Examples 1 and 2 were sub jected to further storage for one week while being exposed to a temperature of 110 F. the bleach composition containing the 4-methyl-7-dimethyl-aminocoumarin was still free of objectionable odor while the odor of the composition containing the diethyl homologue had become substantially more repulsive.

Example 4 A bath is prepared using one part of a perborate bleach as used in Example 1 and 400 parts "of water at F. A second bath is prepared using one part of the perborateaminocoumarin composition of Example 1. Ten parts .The procedure of Example 4 is repeated except the nylon fabric is replaced by acetate fabric. The acetate fabric treated in a bath according to this invention is substantially whiter when examined in daylight as compared to the fabric treated in a bath containing only the perborate bleach.

Example 6 The procedure of Example 4 is repeated replacing the nylon fabric with wool. Repeated workings in baths having a composition according to this invention result in a. substantially greater whitening effect on the wool than when worked in the bath containing only the perborate composition.

Example 7 A composition according to Example 1 is added to water at 100 F. containing a detergent and nylon garments are added and washed for 15 minutes followed by rinsing and drying. The garments are substantially whiter and brighter than equivalent nylon washed using only the detergent and perborate bleach.

4 What I claim is:

thetic protein fibrous material which comprises a bleaching mixture whose only active chemical bleaching ingredient is about 30% by weight of the mixture sodium perborate, the said bleaching mixture having admixed therein from 0.01 to 2.0% by weight of 4-methyl-7-dimethylaminocoumarin.

2. The compositions of claim 1 in which the amount of the said coumarin admixed with said bleaching mixture is from 0.1 to 1.0%.

3. A process for whitening and brightening natural protein and synthetic fibrous materials which comprises treating said fibrous materials with a solution formed by dissolving, in about 400 parts of Water, one part of a bleaching composition consisting essentially of a chemical bleach whose only active chemical bleaching agent is about 30%,- by weight of the mixture, of sodium perborate and from about 0.01% to about 2.0% by weight, of 4-methyl-7- dimethylaminocoumarin as an optical bleach.

References Cited in the file of this patent UNITED STATES PATENTS 2,610,152 Ackermann Sept. 8, 1952 2,654,713 Fleck Oct. '6, 1953 2,692,238 Hendrix Oct. 19, 1954 2,706,178 Young Apr. 12, 1955 2,763,618 Hendrix Sept. 18, 1956 2,791,564 Fleck May 7, 1957 FOREIGN PATENTS 496,903 Belgium Nov. 3, 1950

Claims (1)

1. A BLEACHING POWDER FOR WHITENING NATURAL AND SYNTHETIC PROTEIN FIBROUS MATERIAL WHICH COMPRISES A BLEACHING MIXTURE WHOSE ONLY ACTIVE CHEMICAL BLEACHING INGREDIENT IS ABOUT 30% BY WEIGHT OF THE MIXTURE SODIUM PERBORATE, THE SAID BLEACHING MIXTURE HAVING ADMIXED THEREIN FROM 0.01 TO 2.0% BY WEIGHT OF 4-METHYL-7-DIMETHYLAMINOCOURMARIN.