IE45372B1 - Method of activating percompounds - Google Patents

Abstract

The percompounds activator used in the composition corresponds to the formula: in which the symbols R1 to R6 represent hydrogen or certain alkyl, hydrocarbon or aromatic radicals according to Claim 1, it being possible for R5 and R6 additionally to represent certain acyl groups. It has the effect of causing a more rapid oxidation or bleaching at a given temperature, or an equivalent bleaching at a lower temperature.

Description

The present invention relates to the use of ct-acyloxyLT,M'-polyacylna.Lanamicte3 as activators for inorganic and organic psrcompounds and more particularly as activators for hydrogen peroxide, for its addition products with organic substances S such as urea and dicyclohexylamine, and also of its inorganic psrsalts such as perborates, psrcarbonates and perphosphates-.

The action of aqueous solutions of percompounds as oxidising and bleaching agents becomes effective only at temperatures above 70°C and usually at temperatures from 80 to 100°C.

The prior art describes numerous products which can act as activators of percompounds, i.e. which result in a more rapid oxidising or bleaching action than that which is customarily observed, or which result in the said action taking place under much milder temperature conditions than those which it is necessary to use in their absence. All such compounds are generally characterised by the fact that they have one or more per-hydrolysable functions.

In the bleaching field a certain number of activator compounds have begun to be developed commercially. The literature on this subject mentions especially poly-N-acetylated heterocycles such as hydantoins, glycolurils, bensimidazoles and diketopiperasines. However, this particular line of products has not been pursued because these substances display the major disadvantages of being unstable to ambient humidity and of hydrolysing spontaneously, thus rapidly losing their activating capacity. Moreover, these products require special 3373 precautions to be taken during storage and handling, or when added to other ingredients such ae those used for example in the customary composition of a washing ma.-der. Various solutions such as coating or wrapping, separate packing, or addition of desiccating products huve keen proposed to overcome this disadvantage but these have not been satisfactory either because putting ΐ-ΐ·Ά i?:to practice gives rise to technical problems, or because they lead to considerable increase in the co?·': -rice c-f the active subr-tanee.

The present inv'.v.:ti-.v provides a method of activating percompounde, and cempjsitrcr.a containing a peroompound and an activator therefor, a-- r tcx?. 2it?.vr..i using stable for long periods in the solid g'-atc aval conditions of storage and packing.

Accordingly, tha i-j.- -. invention provides a method of activating a percomponnd, v hiv' v;v:hod comprises subjecting the perccmpound to the irfluou· < · as activator, an ci-acyloxyK,J»’-poIyacylraalosa£ids -.-:-. ins general formula: h ‘fit·?., .

B. too-(2) wherein ea-'b of R,. Eo.· /:,, : .- ' -.·.. which msy be identical or different.· is eh-;s-., » Λ-ο-'ι 3 v.ydisger. atom, substituted or unsubstitvr.j’d vt-· .n ' - :.:»diesla having from 1 to 11 tarb-.v: atema, substi.ω~' ΐ >r-. -.Cisuhativuted branched chain alkyl and eyeloaIky1 bm.» from 3 to 12 carbon atoms, substituted or ur^dbst’tuttr· hyd.-'.uarbon radicals having from - 4 4S373 to 12 carbon atoms and including at least one aromatic nucleus; or wherein R , R , R , R are as defined above and R_ and/or X Z 3 4 5 6 correspond to an acyl group COR?, wherein R? is a hydrogen atom or a substituted or unsubstituted straight chain or branched alkyl radical having from 1 to 12 carbon atoms or a substituted or unsubstituted hydrocarbon radical having from 6 to 12 carbon atoms and including at least one aromatic nucleus. Examples of typical atoms or groups which can ba substituents of the said alkyl, cycloalkyl or hydrocarbon radicals are chloro, bromo, fluoro and iodo atoms and hydroxy, nitro, alkoxy, amino, ester, amide or hydrocarbyloxy groups.

Purely by way of illustration, examples of the a-acyldxyN,H'-polyacylmalonamides constituting activators for percompounds according to the present invention are a-acetoxy, α-methyl-N, N115 diacetyl nalonamide; a-propiono;y, a-ethyl-N,hr‘-dipropii>nylmalonamide; and α-acetoxy, a-mathyl-N,N'-dipropionylmalonamide.

A particularly advantageous method of using the activators according to the present invention is to add them to the percompound in an amount of approximately 0.33 mol per mol of percompound to be activated. However, according to requirements, it is possible to operate vzith a deficit or an excess of activator. Preferably the molar ratio of activator to percompound is from 0.1 to 10.

The activators according to the invention may be used in all cases where a percompound is used to obtain an oxidising or bleaching action, for example in the bleaching of textile fibres, oils, greases and waxes, hair and skin treatments in cosmetology, the passivation of metallic surfaces and in purification, disinfection and sterilisation processes.

The activators of the invention when added to the percompound or to a formula containing one or more percompounds. - 5 45378 for example a washing powder, make it possible to obtain a more rapid bleaching or oxidising effect at a given temperature, they likewise make it possible to obtain the same bleaching effect when operating at a lower temperature than is customary with conventional bleaching agents.

For example, in the presence of sodium perborate in a wash powder medium, the activators according to the invention make it possible to «otain, at temperatures of from 30 to 50°c, a bleaching action substantially equivalent to that obtained in their absence at higher temperatures of the order of 80°C.

A method of preparing seme of the α-acyloxy-N,Ν'-diacylmalonamides used as activators in the present invention is described in Patent Specifisatieλ No. 45373.

The following Examples illustrate the invention.

Examples ’ to 3.

Into a compartment cf α- AHIBA water bath heated to 40°C, there were introduced 250 ml of an aqueous solution containing 5 g per litre of a weeis·»’ g powder having the following composition: - 6 45372 Constituents % by weightKa2Si°3 5.34 Na2S°4 7.25 Na2co3 2.55 Na HPO 0.95 Na.P O 3.99 4 2 7 Na P-0.. 30,41 5 3 10 NaP03 11.92H2° 18.9 Surfactants 14 Blues, various to make up composition to 100% and 1.7 g per litre of sodium perborate tetrahydrate.

Into tfce other compartment, the same solution was placed vzith the further addition of tha activator to be tested, at the concentration of 1 g per litre.

Into each of the compartments there vzas placed a piece of EMPA cotton tissue impregnated 'with standardised wine stains, originating from the Saint-Gall (SWITZERLAND) laboratory.

After 15 minutes washing, the tissues were rinsed in a current of cold water, then dried at ambient temperature.

The bleaching power is defined by the difference between the whiteness indices (measured by means of a Carl ZEISS ELREPHO'1 spectrophotometer no. 6 filter) before and after washing, reduced to a percentage of a maximum whiteness of 100. 4S372 - 7 Variation in whiteness Bleaching power (%)= —---x 100 100 — initial whiteness The following results were obtained: Example No. Activator % bleaching ΚΑΜΕ Concentration g/i without activator with activator 1 a-acetoxy, ci-mathy 1-fi. *i1 diacetylmalonaraide 1 40 61.5 2 a-propionoxy, α-ethyl-N,N'di-propionylmalonamide 1 40 59.5 3 α-acetoxy, j 1 a-methyl-N.N'- [ dipropionyl- 1 malonamide j 40 61.5 Examples 4 to 6.

The same process conditions as those described in the preceding Examples were adopted, but with a washing temperature of 20°C instead of 40°C.

Example No. Activator % bleaching NAME Concentration 3/1 without activator with activator 4 a-acetoxy.. α-methy l-N, N ‘ diacetylmalonamide 1 31.5 45.3 5 a-propionoxy, a-ethyl-N, N' dipropionylmalonamide 1 31.5 43.B 6 a-acetoxy, α-methyl-N,N'dipropionylmalonamide 1 31.5 44.8 - 8 Λ3373

Claims (12)

1. CIAIMS;

1. A method of activating a percompound, which method comprises subjecting the percompound to the influence of, as activator, an a-acyloxy-KT,N‘-polyacylmalonamide of the general 5 formula: I 5 COKCOR, I R^COC—C—R 2 (I) ί COKCOR, ί 4 R 6 wherein each of R^, R^· ^3» R />·· κ ς and Kg, which may be identical or different, is chosen from a hydrogen atom, substituted or unsubstituted straight chain alkyl radicals hav10 ing from 1 to 11 carbon atoms, substituted or unsubstituted branched alkyl and cycloalkyl radicals having from 3 to 12 carbon atoms, substituted or unsdbstituted hydrocarbon radicals having from 6 to 12 carbon atoms and including at least one aromatic nucleus; or wherein R^, R 2 , R^, R^ are as 15 defined above and R^ and/or Κθ correspond to an acyl group COR?, wherein R? is a hydrogen atom or a substituted or unsubstituted straight chain or branched alkyl radical having from 1 to 12 carbon atoms or a substituted or unsubstituted hydrocarbon radical having from 6 to 12 carbon atoms and including 20 at least one aromatic nucleus.

2. A method according to claim 1, wherein the substituents on the said alkyl, cycloalkyl, or hydrocarbon radicals are chosen from chloro, bromo, fluoro and iodo atoms and hydroxy, nitro, alkoxy, amino, ester, amide or hydrocarbyloxy groups.

3. A method according to claim 1 or 2, wherein the per25 4. S373 - 9 compound is hydrogen peroxide, or an organic addition compound thereof.

4. A method according to claim 1 or 2, wherein the percompound ia a perborate, a percarbonate or a perphosphate.

5. 5. A method according to claim 1 substantially as described in any one of the foregoing Examples 1 to 6.

6. An oxidisin'; or bleaching composition including a percompound and an activator of general formula (I) as defined in claim 1. 10

7. A composition according to claim 6, wherein the molar ratio of activator to percompound is from ΰ.1 to 10.

8. A composition according to claim 7, wherein the molar ratio of activator to percompound is approximately 0.33.

9. A composition according to any one of claims 6 to 8, 15 wherein the percompound is hydrogen peroxide, or an organic addition compound thereof.

10. A composition according to any one of claims 6 to 8, wherein the percompound is a perborate, a percarbonate or a perphosphate. 20

11. A washing powder including a composition as claimed in any one of claims 6 tc 10,

12. A washing powder substantially as described in any one of the foregoing Examples 1 fo 5.