US1754914A - Bleaching method and composition - Google Patents

Description

Patented Apr. 15, 1930 UNITED STATES PATENT OFFICE WILLIAM B. STODDARD, OF STAMFORD, CONNECTICUT, ASSIGNOR TO PILOT LABORA- TORY, INC., OF ARLINGTON, NEW JERSEY, A CORPORATION 01 NEW JERSEY nmmcnmo mmnon AND comrosrrron W No Drawing.

My invention relates to an organic peroxide and per-acid composition and to its method of manufacture, and to a method of bleaching organic materials with organic peroxides and similar compounds.

Organic peroxides are, in general, unstable compounds subject to decomposition and oxidation with evolution of heat and are, therefore, of an explosive nature. Consequently their production, transportation and use in a pure form are hazardous, inasmuch as an initial, local decomposition, induced by the hydrolytic action of moisture or otherwise, tends to increase with progressive speed and violence. To reduce this hazard the peroxides, which are generally in the form of a fine powder, are mixed with powdered, inert materials such as dicalcium phosphate which, by absorption of heat, prevent the local acceleration of the decomposition and the resulting tendency to explode. To be completely effective, the inert material must be very intimately and finely mixed with the peroxide to produce an entirely homogeneous mixture in order to ensure against local concentrations or masses'of the pure peroxide. A perfectly uniform mechanical mixture of two powders, such as the inert material and the peroxide is, however, not obtained easily and with certainty.

To remove to the greatest possible extent all tendency to hydrolytic decomposition the peroxides must, at the time of their manufacture, be carefully and completely dried by means of a current of heated air. This drying, however, adds to the complexity and the hazards of manufacture, as heating and drying in this manner may itself induce such decomposition.

When the peroxides are used in the bleaching of milling products such as flour, the necessity of mixing a small amount of the peroxide in powdered form uniformly and finely throughout the flour also limits the effectiveness of the peroxide, in that, at best only a limited surface contact between the particles of flour and the particles of peroxide is obtained. Moreover, as the coloring matter to be oxidized is largely enclosed or dissolved in the fatty or waxy constituents Application filed October 28, 1928. Serial No. 814,545.

of the flour and is thus not directly accessible to the peroxide, which directly touches only a the surface of the .waxy particles,

the oxidizing and bleaching action of the of bleaching materials with organic peroxides or per-acids in which the peroxides and materials are brought into the most efi'ective relation for efiicient action; to provide a simple and non-hazardous method of making dry peroxides or per-acids; to provide a peroxide composition in which homogeneity and uniformity may be ensured; and to a method of bleaching in which the organic peroxide or per-acid may be applied homogeneously andwith uniformity to various types of material to be treated.

With these and other objects in view, which will more fully appear hereinafter, the invention comprises the peroxide composition and its method of manufacture and the method of bleaching organic materials by means of the peroxide compositions described and set forth in the following specification and claims.

In my invention the organic peroxide or per-acid or a mixture of organic peroxides or per-acids is dissolved in an organic solvent such as an inert mineral oil, a vegetable or animal oil, hydrocarbons of the aliphatic or of the aromatic series, acetone, ethyl acetate, or othersuitable non-aqueous solvents. By dissolving the peroxides in solvents of this character, a uniform, homogeneous composition is obtained. Contrary to what might be expected when inflammable organic oils that, under normal conditions, are inert to the peroxide, are mixed with the peroxide, the peroxide is thereby stabilized and rendered secure against violent decomposition and explosion. Inasmuch as the peroxides are in solution in the solvent, the composition is uniform throughout and the existence of local masses of the peroxide, in which the decomposition once initiated would proceed with increasing force, is avoided. Any heat generated by the decomposition of the dissolved peroxide is immediately quenched in the body of the solvent.

Although the dissolved peroxides are stabilized against violent decomposition, their bleaching activity is increased. This may be due, in large part, to a greater uniformity in their distribution throughout the material to be bleached for, instead of being disseminated throughout the material in discrete particles, the solvent tends to wet and seep or creep uniformly throughout each particle, thereby bringing an equal amount of the peroxide to each portion to be bleached. -Moreover, where the chromophoric materials of the substance to be bleached are dissolved or contained within waxy or oily constituents, as is usually the case in milling products, and a mutual solvent of these waxy constituents and the peroxide is employed in which to dissolve the peroxides, the two may be brought into a common solution and thus into the most effective relation for reaction.

Any suitable peroxy compound such as organic peroxides or per-acids may be used. As examples, peroxides or peroxy compounds of the higher fatty acids such as caproyl, lauryl, palmityl, oleyl, stearyl peroxides and per-acids or mixtures thereof, or mixed per- A oxides of these acids and others may be used.

These peroxides and peroxy compounds of the higher fatty acids are, in general, soluble to a greater or. less extent in mineral oils and other non-aqueous solvents.

In producing the peroxide composition of my invention, the method of obtaining a dry peroxide is greatly simplified. To obtain a dry, non-aqueous solution of the peroxide, the peroxide may be simply dissolved in the nonaqueous solvent and the solution then dried chemically by means of a suitable drying agent, such for example as anhydrous calcium chloride, sodium sulphate, etc., thereby elimi- ,nating the necessity for drying with air at elevated temperatures with the attendant danger of local overheating and of initiating an 1 explosive reaction.

In bleaching materials with the peroxy composition of my present invention, the material may be sprayed into a stream of flour or other milling product, or into a stream of any desired material to be bleached. An initial fine and uniform distribution of the composition throughout the material to@ be bleached is thus obtained and is supplemented by a further spreading of the disseminated particles throughout the composition.

As an example of the manner of forming and stabilizing organic peroxide com ounds according to my invention, the followmg detailed process is given: In a vessel fitted with an agitator are placed litres of hydrogen peroxide solution of a strength of 7 of hydrogen peroxide. To this there are then added about 150 litres of a 1% sea solution. The resulting solution is then cooled by the addition of chipped ice an the mixture is agitated. During the agitation, 22 litres of a caustic soda solution containing 0.35 kgs. of commercial caustic soda per litre, and 30 kgs. of a mixture of acid chlorides containing 25 kgs. of cocoanut oil acid chlorides, and 5 kgs. of benzoyl' chloride, are

t oroutghly added simultaneously. .The reaction mixture is kept near 0 0., throughout the operation by the continued addition of chipped .ice. After the completion of the reaction, which may take from 10 to 20 minutes, and which may be detected by the disappearance of the odor of acid chloride, the mixture may be employed is a chemically inert, tasteless andodorless, petroleum distillate of low volatility which is known in the trade as Marcel. The quantity of the solvent, Marcol is then added directly to the bath and, after all of the peroxide is dissolved and taken up therein, the solvent and the dissolved peroxide are permitted to rise to the top, and the watery portion is drawn off from below the oily layer. The slightly moist, oily layer of peroxide solution is then washed with water and is thoroughly and com letely dried by the addition of particles 0 anhydrous calcium chloride or sodium sulphate, which are thereafter filtered from the peroxide solution.

The dry peroxide solution resulting from the above steps is found to be a relatively suitable and eflicient bleaching agent as comsolution produced. In using the composition for bleaching materials such as flour, it will be brought to a fine state of sub-division and suspension in the atmosphere by spraying.

If used for bleaching liquid oils, the peroxy solution may be mixed directly with-the oil and a solvent that is, itself, miscible or soluble in the oil being treated is selected.

As changes of o eration could be made within the scope o my invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. 0

Having now described my invention what I claim as new and desire to secure by Letters Patent is:

1. A composition of the type described which comprises an organic peroxid dissolved in a non-aqueous solvent.

2. A composition of the type described which comprises a non-aqueous solution of a peroxy compound of a fatty acid.

3. A composition of the type described which comprises a non-a ueous solution of a complex peroxid of a atty acid and an aromatic acid.

4. A composition of the type described which comprises an inert mineral oil solvent and a complex peroxid of a fatty acid and.

of benzoic acid dissolved in said mineral oil solvent. I a

5. A method of bleaching which comprises treating the material to be bleached with a non aqueous solution of an organic peroxy compound.

6. A method of bleaching which comprises dissolving an organic peroxy compound in a non-aqueous solvent and disseminating said solution throughout the material to be bleached.

7. A method of bleaching which comprises dissolving an organic peroxy compound in a solvent of the chromophoric constituents of said material to be bleached, and mixing said solution with said material to be bleached.

8. A method of bleaching which comprises acting upon the chromophoric constituents of the material to be bleaclied with organic peroxy compounds in a common solution with said chromophoric constituents.

9. A method of forming peroxy compounds which comprises treating an acyl chloride with hydrogen peroxide to form an organic peroxide, dissolving said peroxide in a nonaqueous solvent, and chemically drying the resulting peroxide SOllltlOEl.

10. A method of forming a peroxy composition which comprises treating a mixture of a fatt acid chloride and benzoyl chloride with hy rogen eroxide to form a compound organic peroxi e, dissolving said peroxide in a non-aqueous solvent, and chemically drying said peroxide solution. A

11. A method of forming peroxy compositions which comprises treating an acyl chloride with hydrogen peroxide, dissolving the resulting organic peroxide in a nonaqueous solvent, and drying. the resulting solution with an anhydrous salt.

12. A method of bleaching flour and other milling products which comprises spraying a non-a ueous solution of organic peroxides Y uniform y throughout said milling products,

and permitting said peroxides to react therewith,

13. A method of bleaching flour and other milling products which comprises spraying a non-aqueous solution of eroxy compounds of organic acids throug out said milling products, said non-aqueous solvent being a solvent for the waxy chromophoric constituents of said milling product, and permitting said sprayed solution to remain in contact with and spread throughout said milling products.

14. A composition of the type described which comprises an inert mineral oil solvent and a mixture of complex peroxides of cocoanut oil fatty acid derivatives and of henzoic acid dissolved in said mineral oil solvent.

15. A method of forming a peroxy composition which comprises treating a mixture of cocoanut oil fatty acid chlorides and benzoyl chloride with hydrogen peroxide to form a mixture of complex organic peroxides, dissolving said peroxides in -a non-a ueous solvent, and chemically drying sai peroxide solution.

16. A method of forming a peroxy composition which comprises treating a mixture of cocoanut oil fatty acid chlorides and benzoyl chloride in approximately molecular proportions with hydrogen peroxide to form a mixture of complex organic peroxides, dissolving said peroxide in a non-aqueous solvent, and chemically drying said peroxide solution.

17. A method of bleaching flour and other milling products which comprises s raying a non-aqueous solution of a mixture 0 peroxy compounds, benzoic acid and cocoanut oil fatty acid derivatives throughout said milling products, said non-aqueous solvent being a solvent for the waxy chromophoric constituents of said milling products, and permitting said sprayed solution to remain in contact with and to spread throughout said milling products.

In testimony whereof I hereunto afiix my signature.

WILLIAM B. STQDDARD.