Dry, Free-flowing Hair Bleaching Composition

Abstract

An essentially dry, free-flowing bleaching composition comprises granules of an essentially homogeneous mixture of discrete particles including a bleaching agent such as a per salt and a binding agent such as polyvinylpyrrolidone or glucose.

Description

The present invention relates to a novel hair-bleaching composition and more particularly to a dry, free-flowing granular hair-bleaching composition wherein the active bleaching agent is essentially homogenously distributed throughout the granular composition.

Heretofore, liquid hair-bleaching or oxidizing compositions have been employed, which compositions comprise a solution of per salts such as perborates, persulfates, and the like in hydrogen peroxide. These liquid compositions, however, have certain disadvantages such as poor shelf-life and cumbersome and expensive shipping characteristics.

In an effort to overcome these disadvantages solid hair-bleaching compositions were developed. Generally known solid hair-bleaching compositions are fine-grained powders which are dissolved in hydrogen peroxide just before use. While known bleaching compositions in solid form thus eliminated the principal disadvantages associated with liquid compositions, nonetheless presently available solid compositions also exhibit certain other disadvantages. Thus, these fine-grained powders, which comprise an intimate mixture of discrete particles of the various ingredients comprising the bleaching composition were found to exhibit a lack of uniformity in the concentration of the bleaching composition when dissolved in an appropriate solvent, such as hydrogen peroxide. This lack of uniformity is attributed at least in part to the fact that certain of the ingredients of the composition have different apparent densities, which causes a separating out of the different constituents of the powder in the course of transportation and storage. As a result the heavier elements exhibit a tendency to stratify and collect in the lower portion of a mass of the composition while the lighter elements tend to be found at the top thereof. Accordingly, an equal portion of the powdered composition taken from the upper and the lower part of a mass of the composition did not have the same chemical composition and did not therefore exert the same bleaching effect. To obviate this difficulty, it was found necessary to thoroughly mix the powdered composition each time before using it. This was found not only to be inconvenient and time-consuming, but often the user neglected to perform this mixing operation with the result that a bleaching operation in which such a composition was used was generally unsatisfactory.

Moreover, it was noted that the measuring of the amount of powder, generally done with a spoon, yields rather unlike results because of different mechanical characteristics that a powder of a specific composition may have.

It is therefore a principal object of the present invention to provide a new bleaching composition that eliminates the above mentioned disadvantages.

The novel bleaching composition of the present invention comprises a dry, free-flowing product which is dissolved at the time of use in a solvent such as water or hydrogen peroxide, the said composition being characterized in that the different oxidizers in powder form that are contained in the composition are agglomerated as granules, after having previously been homogeneously mixed, by means of a binding agent that is soluble in the medium in which the composition is to be dissolved.

Binding agents that can be utilized for preparation of compositions of the present invention must have the dual characteristic of (1) being soluble in the solvent of the composition (generally an aqueous solution of hydrogen peroxide) and (2) to provide granules that do not stick, i.e. are free-flowing and exhibit uniform storage and dispensing characteristics.

Representative binding agents usefully employed in the present invention include polyvinyl pyrrolidone having a molecular weight ranging from about 40,000 to 400,000 and a specific viscosity ranging from about 0.22 to 1.7 and glucose.

The bleaching powder mixture to which the binding agent is added includes as an active bleaching agent at least one water soluble per salt such as sodium or potassium persulfate or their mixtures in amounts of about 30-50 percent by weight of the total bleaching powder mixture. Other conventional hair-bleaching per salts can be employed such as sodium or potassium perborate and the like, alone or in admixture with the persulfates. The bleaching powder mixture also contains about 10-20 weight percent of magnesium carbonate. The remainder of the bleaching powder mixture comprises such conventional inerts or extenders as colloidal clay, thickeners such as carboxymethyl cellulose or the like, perfumes, ammonium salts such as ammonium sulfate and a wetting agent.

The proportion of a solvent-free binding agent to bleaching powder mixture in the novel dry, free-flowing bleaching composition of this invention ranges, generally, between about 0.1-10 and, preferably, between 3-8 percent based on the weight of the bleaching powder mixture. Prior to admixing the binding agent with the bleaching powder mixture, the binding agent is dissolved in a carrier such as water or a lower alkanol, for instance, ethyl alcohol or isopropyl alcohol, or their mixtures to provide a binding agent solution in which the concentration of the binding agent ranges between about 0.5-10, and preferably about 5 weight percent, of the resulting solution.

In preparing the granules which comprise the dry, free-flowing bleaching composition of this invention and which, ocnveniently, have an average diameter ranging between about 1-6 mm, the ingredients constituting the bleaching powder mixture are thoroughly and intimately mixed in any conventional mixing apparatus, including a conventional granulating device, i.e. one having a fitted rotatable drum provided with means to automatically discharge the resulting granules on attainment of a specified size, to provide an essentially homogeneous powdered mixture. Thereafter, the binding agent solution is then thoroughly admixed with the bleaching powder mixture in, for instance, the same granulating apparatus to produce granules of a dry, free-flowing bleaching composition. Generally, the production of the granules is effected at atmospheric pressure and at a a temperature ranging from about ambient temperature to about 40.degree. C, thereby eliminating essentially the binding agent carrier such as water, alcohol or their mixtures.

It has also been found, that when the carrier for the binding agent is or contains water, and when the bleaching powder mixture contains an ammonium compound, the elimination of the carrier during the formation of the granules is often accompanied by a loss of ammonia. Accordingly, it has been found convenient to include, in such instances, about 0.05 to 0.2 weight percent ammonia in the binding agent solution to compensate for any such ammonia losses during this stage of the production of the granules. Alternatively, the amount of ammonium compound present in the bleaching powder mixture can be increased in the amount of the predicted ammonia loss.

The granules comprising the dry, fee-flowing composition of this invention are characterized in that they are generally uniform in composition and size and thus do not exhibit deleterious stratification or sedimentation properties. Accordingly, measured amounts of the granules made in accordance with the present invention provide more uniform concentrations than essentially an equally measured amount of conventional fine powdered bleaching ingredients not in the granulated or agglomerated form. Additionally, it has surprisingly been found that the presence of the binding agent, especially polyvinyl pyrrolidone, significantly improves the dissolution characteristics of the solid constituents in the hydrogen peroxide containing medium employed when the bleaching composition is to be put into use. By comparison, a bleaching composition formulated using essentially the same bleaching powder composition but in the form of a simple mechanical mixture of polyvinyl pyrrolidone obtained by stirring or mixing the polyvinyl pyrrolidone into the bleaching powder, requires a significantly longer time to effect dissolution of the resulting composition in hydrogen peroxide. Further, the bleaching effect using the composition of this invention has been found to be markedly superior to the bleaching effect using essentially the same bleaching powder mixture per se in powdered or ungranulated form.

In order that the invention may be better understood, the following examples are given which describe the dry, free-flowing bleaching composition and a process for producing the same. Unless otherwise specified, all parts and percentages are by weight.

EXAMPLE 1

In a commercial granulator there are placed 25 kg of a bleaching powder mixture having the following composition:

Potassium persulfate 30 % Magnesium carbonate 20 % Magnesium oxide 15 % Ammonium sulfate 4 % Colloidal clay 28.5% Sulfonated partly oxyethylene fatty alcohol, sodium salt , of the formula : R -- (C.sub.2 H.sub.4 O).sub.n O--SO.sub.3 Na in which R represents lauryl and n is 3 0.3% Thickener, carboxymethyl cellulose 2 % Perfume 0.2 %

25 kg of a 5 percent polyvinyl pyrrolidone solution in isopropyl alcohol is sprayed onto the powder while the mixture is agitated at ambient temperature. The mixture is then dried and the resulting granules exhibit good composition uniformity characteristics and can be stored without exhibiting any substantial tendency to stick together. When these granules are mixed with hydrogen peroxide they yield a very smooth paste that can readily be applied to the head. The composition thus obtained allows good bleaching of the hair, superior to that obtained if the bleaching powder mixture alone is employed.

EXAMPLE 2

Granulation at ambient temperature is effected for 25 kg of a bleaching powder mixture of the following composition:

Sodium persulfate 20 % Potassium persulfate 30 % Ammonium sulfate 4 % Magnesium carbonate 10 % Magnesia 5 % Colloidal clay 28.5 % Gum tragacanth (thickener) 2 % Sulfonated partly oxyethylene fatty alcohol, sodium salt, of the formula: R -- (C.sub.2 H.sub.4 O).sub.n O--SO.sub.3 Na in which R represents lauryl and n is 3 0.3 % Perfume 0.2 %

using 25 kg of a 5 percent solution of polyvinyl pyrrolidone K 30 (Molecular Weight 40,000 , specific viscosity 0.225) in water containing 0.05 percent ammonia. Results comparable to those of Example 1 are obtained.

EXAMPLE 3

Proceeding as indicated above, granulation of 25 kg of the bleaching powder mixture of Example 1 is effected at ambient temperature, using 30 kg of a 5 percent glucose solution in water containing 0.05 percent ammonia. Results comparable to those indicated in Example 1 are obtained.

EXAMPLE 4

Granulation of 25 kg of a bleaching powder mixture having the following composition is effected at ambient temperature:

Sodium persulfate 20 % Potassium persulfate 30 % Ammonium sulfate 6 % Magnesium carbonate 10 % Magnesia 5 % Colloidal clay 26.5 % Gum tragacanth (thickener) 2 % Sulfonated partly oxyethylene fatty alcohol, sodium salt of the formula: R -- (C.sub.2 H.sub.4 O).sub.n O -- SO.sub.3 Na in which: R represents lauryl and n is 3 0.3% perfume 0.2 %

using 12 kg of a 10 percent polyvinyl pyrrolidone solution in a 50 percent lower alkanol (Et OH) mixture as the binding agent solution. Results obtained are comparable to those described in Example 1.

EXAMPLE 5

In a commercial granulator there are placed 25 kg of a bleaching powder mixture having the following composition:

Potassium persulfate 30 % Magnesium carbonate 20 % Magnesium oxide 15 % Ammonium sulfate 4 % Colloidal clay 28.5 % Sulfonated partly oxyethylene fatty alcohol, sodium salt, of the formula: R -- (C.sub.2 H.sub.4 O).sub.n O--SO.sub.3 Na in which R represents lauryl and n is 3 0.3% Thickener, carboxymethyl cellulose 2 % Perfume 0.2%

12.5 kg of a 5 percent polyvinyl pyrrolidone solution in isopropyl alcohol is sprayed onto the powder while the mixture is agitated at ambient temperature. The mixture is then dried and the resulting granules exhibit good composition uniformity characteristics and can be stored without exhibiting any substantial tendency to stick together. When these granules are mixed with hydrogen peroxide they yield a very smooth paste that can readily be applied to the head. The composition thus obtained allows good bleaching of the hair, superior to that obtained if the bleaching powder mixture alone is employed.

EXAMPLE 6

Granulation at ambient temperature is effected for 12.5kg of a bleaching powder mixture of the following composition:

Sodium persulfate 20 % Potassium persulfate 30 % Ammonium sulfate 4 % Magnesium carbonate 10 % Magnesia 5 % Colloidal clay 28.5% Gum tragacanth (thickener) 2 % Sulfonated partly oxyethylene fatty alcohol, sodium salt, of the formula: R -- (C.sub.2 H.sub.4 O).sub.n O--SO.sub.3 Na in which R represents lauryl and n is 3 0.3 % Perfume 0.2 %

using 25 kg of a 5 percent solution of polyvinyl pyrrolidone K 30 (Molecular Weight 40,000, specific viscosity 0.225) in water containing 0.05 percent ammonia. Results comparable to those of Example 1 are obtained.

Claims

What is claimed is :

1. An essentially dry, free-flowing bleaching composition for use in conjunction with water or aqueous hydrogen peroxide consisting essentially of granules comprising an essentially homogeneous mixture of (a) a bleaching powder consisting essentially of (i) 30-50 weight percent of said powder of a per salt selected from the group consisting of sodium persulfate, potassium persulfate, sodium perborate and potassium perborate (ii) 10-20 weight percent of said powder of magnesium carbonate, and (iii) the remainder being inert extenders and (b) a binding agent selected from the group consisting of polyvinylpyrrolidone having a molecular weight of about 40,000 to 400,000 and glucose, said binding agent being present in amounts ranging from about 0.1 to 10 percent by weight of said bleaching powder.

2. The bleaching composition of claim 1 wherein said granules have a diameter ranging between about 1 to 6 mm.

3. The bleaching composition of claim 1, wherein said binding agent is present in amounts of about 3 to 8 percent based on the weight of said bleaching powder.