US1754913A - Unsymmetrical organic peroxide bleaching agent and method of preparing the same - Google Patents

Description

Patented Apr. 15, 1930 UNITED STATES PATENT OFFICE WILLIAM B. STODDARD, OF STAMFORD, CONIlTECTICUT, AND ROBERT V. TOWNEZND AND VAMAN R. KOKQATNUR, OF KEABNY, NEW-JERSEY, ASSIGNORS TO PILOT LABORA- TORY, INCL, OF ARLINGTON, NEW JERSEY, A CORPORATION .OF NEW JERSEY UNSYMME'IRICAL ORGANIC rnnoxrbn BLEACHING AGENT Am) METHOD or PREPARING THE SAME a Y No Drawing.

products, etc. In itspreferredjembodiment, the invention relates more particularly to a process of and composition for bleaching such organic materials, and particularly food products by means of activated organic perj oxids. The invention also'relates to a process formaking organic peroxids especially suited for bleaching purposes.

Various organic peroxid compounds have heretofore been proposed for use in the bleaching. of milling productssuch as flour, and of fats and oils. These peroxids, of which benzoyl peroxid is a type, have a relatively slight bleaching action. in proportion to the quantity of available oxygen contained in the compounds. Moreover, as they are only slightly soluble in' oils, or other available solvents, the effectiveness of their use as 021- idizing agents is limited, in many instances,

, by the difliculty or inability to, bring them into sufficiently intimate contact with the materials to be oxidized, more particularlywhen the coloring or chromophoric material is dis- .solved'or otherwise incorporated in an oily vehicle or carrying medium.

These various disadvantages are overcome and obviated in our present invention, one

object of which is toprovide a-more, efiicient.

and effective oxidizing composition-and one having maximum bleaching action per unit of oxidizing power.

Another object of the invention is to pro vide a readily solubleoxidizing composition suitable for the bleaching of organic products,

and particularlyof food pro ucts.

Another object is to provide an organic peroxid that is soluble in oils orother vehicles in which thecoloring matters .to be bleached -are-dissolved or carried, and to :in-

crease the solubility' of organicperoxids in such vehicles.

'Furtherobjects and tion areto provide organic peroxide which have an activating action on. other organic peroxide to thereby ncrease the effectiveness features of the inven- Application filed September 8, 1928. Serial Nb. 304,838.

of theoxidizfing or bleachiug action of such peroxids per unit of available oxygen; to provide a process of reparing such soluble and activating peroxi s, and to provide improved methods of bleaching organic materials. 1 In accordance with our invention, the solubility and effectiveness of the peroxid bleaching agentisattained by forming a double or complex peroxid of benzoylor its derivatives, and acyl compounds of materials thatare con-' stitutionally similar or relatedto the chromophoric oils of carotinoids, and particularly similar or relating to the fatty acid constitu ents of oils and fats. The fatty material is preferably combined with the benzoyl'group in the proportion of one molecule of benzoyl to one or more molecules of fatty or'oily constituents, so that the benzoyl'portion' in no case exceeds the proportion, y weight, of the fatty acid. In the com lex eroxid or'mixture of complex peroxlds t us formed an acyl group of a fat is substitutedfor a benzoyl groupin dlbenzoy'l peroxid. The resuiting peroxid or peroxidsmay be represented by the formula CoHl 0040 R ooin which R C 0 represents an a fatty acid of a fat or oil.

When the acyl group of a higher fatty acid, that is, butyric or higher acids, which are of an oily or waxy nature, is used for the substituted acid group, the resulting peroxid has the propertyof being, soluble in, and

acyl group of miscible with oils or o1ly solvents and.

peroxide of other fatty acids. Thus, while enzoyl peroxid' is soluble 'in petroleum solvents to but a negligible per cent, eroxids whose benzoyl portions is about A t of the fatty acid portion, are soluble to almost any extent in these solvents, while a peroxid whose benzoyl portion is about or more, of the fatty acid portionis miscible in all proportions of the same solvent; It also has the capability, whether due to a greater or less degree to this solubility or to catalytic action, or other causes, of activating other organic peroxide, which would otherwise be relative- 1y inactive and sluggish and, therefore, ineffective as bleaching agents. This property of rendering the complex peroxid relatively soluble and an activating agent does not, however, result when there is used for the complex peroxid a lower fatty acid, such as acetic acid, which is water soluble and is not of a fatty oroily nature as are the higher acids, though it is in its chemical constitution a homologue of the higher fatt acids. It is, therefore, to be understood that the higher fatty acids, i. e., those of an oily or waxy nature and which may, for convenience, be

in a common solvent of the oily chromophoric constituents of the material to be bleached also contributes to its effectiveness and availability for the bleaching action, as it enables it to be brought into a uniformly distributed, homogeneous solution in such oily constituents and, therefore, in a more effective state for reaction therewith than is the case of peroxids that are not soluble in an oily solvent.

The material is, therefore, particularly adaptable to the method of bleaching in which it is dissolved in an oil which is then sprayed, or otherwise disseminated, throughout the material to be bleached, and is thereby brought into most intimate contact with the chromophoric oils, or other material, to be acted u on.

The atty acid compound to be peroxidized with the bezoyl group may be a suitable compound of either a single acid, or a derivative of a single acid, or a mixture of acids, either a naturally occurring mixture such as exists in cocoanut oil, or anartificial mixture or blend of acids. The complex peroxid or mixture of complex peroxids may be obtained'by peroxidizing the benzoyl and fatty acid compounds in any suitable manner. Preferred methods of forming the complex or-mixed peroxids are illustrated in the following examples: I

Ewample I In preparing the benzoyl-fatty and complex peroxids, our preferred practice is as ollows:

In a suitable vemel, fitted with any desired means of vigorous agitation, are placed 700 cc. of 7.5% h drogen peroxid and 100 cc. of 1% soap so ution. his mixture is then cooled by adding chipped ice. Then 200 cc. of a solution of caustic soda containing 343 grams NaOH per 100 cc. are added to the chilled mixture, and the mixture is kept cold by theaddition of ice. While the solution is being agitated there is added to it 250 grams of a mixture of acid chlorides of cocoanut oil and benzoyl chloride in the proportion of 232 grams of the chlorids of the total acids of cocoanut oil of an average molecular weight of about 223, and 124 grams of benzoyl chlorid. The mixture is agitated for about seven minutes, keeping the temperature low by the continued addition of chipped ice. The mixture should contain small pieces of ice at all times. During this operation, the peroxids emulsify and the solution becomes like milk. At the end, the solution is rendered slightly acid with sulfuric acid which causes the emulsion to break and watery layer forms at the bottom which may be drawn off. The mixture of complex peroxids is then melted by the addition of warm water, the Water separated, and the product dried and filtered.

We often find it desirable to use as a bleaching agent, a solution of the benzoyl-fatty acid peroxid complex in a mineral oil such as Marcol. This solution may be prepared by adding the desired amount of the solvent to the complex peroxid at any stage of the operation after the peroxidizing action, as given above, has been completed. Analyses show that the product contains a very high percentage of the active oxygen theoretically possible. We have also found that benzoyl peroxid is but very slightly soluble in fatty acid peroxids, and still less so in mineral oils. Consequently, the high solubility of ourproduct in a mineral oil solution to form a solution which is clear and free from solids, evidences' that the peroxids are presentin the form of a true complex or a mixture of such complexes.

Emampze [I In a suitable vessel, fitted with an. agitator, is placed about 1100' cc. of 7.5% hydrogen peroxid. This is cooled to about-0 by the addition of chip ed ice. To this are added about 1575 cc. 0 1% soap solution and 400 cc. of a solution of caustic soda containing 343 grams NaOH-pr 1 litre. The mixture is agitated and kept cold by the addition of ice.

roduct forms an emulsion which is broken .y renderin the solution slightlyacid with sulfuric aci The mixture of peroxids can now be separated, melted, dried and filtered,

is 140.5. To form the complex, one molecule of each is required. As the proportions cited in the second example call for more of the fatty acid chlorids than the above ratio (140.5 parts of benzoyl chlorid to 223.5 parts of the chlorids of the fatty acids) it is evident that the peroxids formed must contain the peroxids of the fatty acids in addition to the complex. We have found that these fatty acid peroxids, while'themselves good bleaching agents, canbe made more eflicient in their bleaching-action by producing them inconnection with the complex, which simulta-neously produces, of itself, two peroxids, as in Example II.

.Th'eabove product (second example) contains the re uired activator in the form of the benzoylatty acid peroxid complex, and is found to be very active and satisfactory in its bleaching efi'ect. Although the group of fatty acids Whose glycerides form the major portion of cocoanut oil have been described specifically infthe above examples, it is to be understood that other groups of higher fatty acids occurring in anynatural fat or oil, or any individual acid therein, or mixtures containing a smaller number of acids than the total represented in any fat or oil, ormixtures of'fatty acids from different sources may be employed. The addition and substitution products of such individual fatty acids or groups or mixtures of the fatty acids may also be employed.

Our invention, therefore, provides a more eiiicient bleaching agent and one in which the available oxygen is utilized most eflicienlly and efiectively; Inaddition, it provides a bleaching agent capable of activating less active bleaching a ents and of rendering their potentiallyavail. le oxygen content effective and efliciently usable. As our peroxid is soluble in materials of the nature associated with the coloring matter to be oxidized, the oxidizing agent reacts in a solution in, and in intimate contact with, the coloring matter, rather than in the heterogeneous state of mixed'powders.

As changes of operation could be made within the scope of our invention, it is intended that all matter contained in the above description shall be interpretedas illustrative and not in a limiting sense.

Having now described our invention, what weclaim as new and desire to secure by Letters Patent is 1. A peroxid of the general formula comprises a mixture of an organic aromatic radical and RCO corresponds to an acyl radical of a mono-basic aliphatic acid having not less than four carbon atoms.

2. An oil soluble peroxid of the general formula R-(.lO--OO.-OC-R in which lit is an aromatic radical and R- -CO corresponds to an acyl radical of a mono-basic aliphatic acid having not less than four carbonatoms.

3. A peroxid of the general formula. R-COOO-OCR in which R is the phenyl radical and R'CO corresponds to an acyl radical "of a mono-basic aliphatic acid having not less than four carbon atoms.

4. An oil soluble mixture of peroxids of aromatic carboxylic acids and mono-basic aliphatic carboxyhc acldshavmg not less than I four carbon atoms and of a peroxid of the general formula RCO-O-OOCR in which R- indicates an aromatic radical and R- CO corresponds to an acyl radical of a mono-basic aliphatic acid having not less than four' carbon atoms, the molecular proportion of the fatty acid peroxid constituent being greater than that of the aromatic peroxid constitutent.

5. Anoil soluble mixture of the peroxids ofbenzoic acid, of a mono-basic aliphatic carboxylic, acid of not less than four carbon atoms and of a peroxid of the general formula R co o .-o Too-R1 in which R 'indica-tes the phenyli ra'dical and R-CO corresponds to-an acyfl radical of a mono-basic aliphatic acid having not less than four car- I bon atoms, the proportion of said fatty acid peroxid constituent being greater than that of the benzoyl peroxid constituent.

6. An oil soluble peroxidofthe general formula RCOOO-OC-R in which R corresponds to the phenyl radical and RCO corresponds to an acyl radical of a mono-basicaliphatic acid having not less than four carbon atoms.

7. An oil soluble peroxid of corresponds to an acyl radical of a monobasic aliphatic acid having not less thanfour carbon atoms.

' 8. An activated organic peroxid which eroxid and of a peroxid of they general ormula R-COO- OOCR in which R indicates an aromatic radical and R.-CO corresponds to an acyl radical of a mono-basic aliphatic acid having not less than four carbon atoms. v

9. An activated. organic peroxid which comprises a mixture of an organic erox1d and of a peroxid cf the general ormula cates the phenyl radical and R-CO corresponds to an acyl radical of a mono-basic aliphatic acid having not less than four carbon atoms.

the general formula RCOO---O'OCR in which R indicates an aromatic radical and RCO 10. A process of making peroxids which comprises treating a mixture of acid chlorids of mono-basic fatty acids having not less than four carbon atoms and benzoyl chlorid with a peroxidizing material.

11. A method of forming complex peroxids *which comprises treating acid chlorids of monosbasic fatty acids having not less than four carbon atoms and benzoyl chlorid with an alkaline solution of hydrogen eroxid.

12. A process of forming a comp ex peroxid which comprises treating a mixture of acid chlorids of mono-basic fatty acids having not less than four carbon atoms and benzoyl chlorid with an alkaline solution of hydrogen peroxid, the fatty acid chlorids being not less than an equi-molecular portion of the benzoyl chlorid.

13. The process of forming mixed peroxids which comprises treating a'mixture of monobasic fatty acid chlorids having not less than four carbon atoms-and benzoyl chlorid with an alkaline solution of hydrogen peroxid and soap.

14. A process of forming complex peroxid which comprises treating a mixture of acid chlorids of cocoanut oil and benzoyl chlorid with a chilled alkaline solution of hydrogen peroxid and soap, acidifying the resulting an emulsion and separating the resulting peroxid.

15. An oil soluble mixture comprising a mixture of the peroxids of mono-basic fatty acids having more than four carbon atoms a and of peroxids of the general formula RCOOOOCR in which R indicates the phenyl radical and R-CO corresponds to an acyl radical of a mono-basic aliphatic acid having not less than four car bon atoms. Y In witness whereof we have hereunto set our hands this 22d day of August, 1928.

WILLIAM B. STODDARD. ROBERT V. TOWNEND.

w VAMAN R. KOKATNUR. v