WO2013178290A1

WO2013178290A1 - Stabilization of phthalimido percarboxylic acids with disaccharides

Info

Publication number: WO2013178290A1
Application number: PCT/EP2012/060449
Authority: WO
Inventors: Amila Bilic; Johannes Georg Winter
Original assignee: Ecolab Usa Inc.
Priority date: 2012-06-01
Filing date: 2012-06-01
Publication date: 2013-12-05
Also published as: EP2855654A1

Abstract

The present invention relates to a mixture for use as a bleaching agent comprising at least one phthalimido percarboxylic acid and at least one disaccharide, to a detergent composition comprising said mixture, and to the use of at least one disaccharide for stabilizing a phthalimido percarboxylic acid in a detergent composition.

Description

Stabilization of phthalimido percarboxylic acids with disaccharides

FIELD OF THE INVENTION

BACKGROUND OF THE INVENTION

In the past, organic peracids have encountered increasing interest in the industrial field, among others due to their excellent properties as bleaching agents in detergent formulations. Therefore, a large number of publications are concerned with organic peracid compounds endowed with the required property of sufficient bleaching activity, said characteristic being essential for an industrial application and a widespread use of such compounds. Thus, many organic straight-chain or cyclic mono- or dipercarboxylic acids are known and used, e.g. in detergent compositions.

A problem with the widespread use of organic peracids arises from their low thermal stability, which makes it necessary to physically or chemically stabilize these compounds. The organic peracids known so far show a significant decrease of active oxygen, even under conventional storage conditions. This is also the case with imido percarboxylic acids as described already in J. Chem. Soc. 1962, 3821 and Chem. Ind. 1961 , 469. Among the imido percarboxylic acids, phthalimido percarboxylic acids have gained a widespread use in industry, especially as bleaching agents in detergent compositions. However, addition of boric acid to phthalimido percarboxylic acids is considered necessary to guarantee a sufficient long-term stability.

As boric acid has become a chemical of high concern, it is to be expected that boric acid will be banned from use in domestic applications in the near future.

Consequently, there is a need for alternative ways of stabilizing phthalimido percarboxylic acids in detergent compositions without making use of boric acid. SUMMARY OF THE INVENTION

The present invention satisfies this need by providing a mixture for use as a bleaching agent comprising at least one phthalimido percarboxylic acid and at least one disaccharide. With the present invention, it is possible to stabilize phthalimido percarboxylic acids so as to minimize a decrease of oxygen under conventional storage conditions, but to avoid the use of boric acid. Thus, detergent compositions may be obtained showing sufficient bleaching activity over time.

DETAILED DESCRIPTION OF THE INVENTION

After extensive studies, the inventors have found that phthalimido percarboxylic acids can be stabilized by disaccharides. This is rather surprising since it was suggested by the prior art that phthalimido percarboxylic acids if not stabilized degrade following a radical reaction pathway.

Without wishing to be bound to any theory, it is assumed that phthalimido

percarboxylic acids in fact degrade by attack of nucleophiles. A plausible degradation scheme of phthalimido peroxyhexanoic acid (phthalimido percaproic acid, PAP) in alkaline conditions is shown in figure 1. According to figure 1 , PAP is degraded to 4- phthalimido-1-hexanol and carbon dioxide via an electrocyclic reaction. As a consequence, the presence of at least one disaccharide would prevent nucleophiles from degrading PAP either by excluding reactive nucleophiles, by blocking

nucleophilic reaction sites at PAP and/or by catching nucleophiles with electrophiles other than PAP.

Therefore, the present invention is directed to a mixture for use as a bleaching agent comprising at least one phthalimido percarboxylic acid and at least one disaccharide.

There is no restriction as concerns the chemical nature of the at least one

disaccharide. Thus, the at least one disaccharide may be either a reducing or non- reducing disaccharide. Besides, the at least one disaccharide may be hydrous or anhydrous.

Therefore, the present invention also relates to the mixture described above, characterized in that it comprises at least one reducing disaccharide. The present invention further relates to the mixture described above, characterized in that it comprises at least one non-reducing disaccharide.

Suitable disaccharides for use according to the present invention are cellobiose, gentiobiose, isomaltose, isomaltulose, lactose, lactulose, iaminaribiose, maltose, maltulose, melibiose, neohesperidose, neotrehalose, nigeriose, rutinose, sophorose, saccharose, and trehalose, wherein lactose represents the most preferred

disaccharide.

Therefore, the present invention also relates to the mixture described above, characterized in that it comprises at least one disaccharide selected from the group consisting of cellobiose, gentiobiose, isomaltose, isomaltulose, lactose, lactulose, Iaminaribiose, maltose, maltulose, melibiose, neohesperidose, neotrehalose, nigeriose, rutinose, sophorose, saccharose, trehalose, and combinations thereof. The present invention further relates to the mixture as described above, characterized in that it comprises lactose.

Also, there is no restriction as concerns the chemical nature of the at least one phthalimido percarboxylic acid. Suitable phthalimido percarboxylic acids for use according to the present invention may be selected from the phthalimido

percarboxylic acids of the general formula (I), where n is an integer of from 1 to 5:

Thus, suitable phthalimido percarboxylic acids for use according to the present invention may be selected from the group consisting of phthalimido peracetic acid (n=1), phthalimido perpropionic acid (n=2), phthalimido perbutyirc acid (n=3), phthalimido peramylic acid (n=4) and phthalimido percaproic acid (n=5), wherein phthalimido percaproic acid represents the most preferred phthalimido percarboxylic acid.

Therefore, the present invention also relates to the mixture described above, characterized in that it comprises at least one phthalimido percarboxylic acid selected from the phthalimido percarboxylic acids of the general formula (I) above, where n is an integer of from 1 to 5. The present invention further relates to the mixture described above, characterized in that it comprises phthalimido percaproic acid.

Phthalimido percarboxylic acids and especially phthalimido peroxycaproic acid may be prepared as described in EP 0 325 288 A1 and EP 0 349 940 B1 , respectively. Thus, a substrate selected from phthalimido carboxylic acids and anhydrides thereof having a structure corresponding to the desired percarboxylic acid e.g. of the general formula (I) may be reacted with concentrated H2O2 in a reaction medium selected from concentrated H₂S0₄ and CH₃SO₃H or in an alkaline medium, and the

percarboxylic acid is then separated from the reaction mixture by conventional and known techniques.

In order to obtain optimum stabilization of the at least one phthalimido percarboxylic acid, the content of disaccharide in the mixture should range between 1 and 50 % by weight, preferably between 1 and 25 % by weight, more preferably between 1 and 10 % by weight, most preferably between 2 and 5 % by weight based on the total weight of the mixture.

Therefore, the present invention also relates to the mixture described above, characterized in that the content of disaccharide is between 1 and 50 % by weight, preferably between 1 and 25 % by weight, more preferably between 1 and 0 % by weight, most preferably between 2 and 5 % by weight based on the total weight of the mixture.

Advantageously, the weight ratio of phthalimido percarboxylic acid to disaccharide is between 20:1 and 1 :1 , preferably between 10:1 and 1 :1 , more preferably between 5:1 and 1 :1 , most preferably between 2:1 and 1 :1.

Therefore, the present invention also relates to the mixture described above, characterized in that the weight ratio of phthalimido percarboxylic acid to

disaccharide is between 20:1 and 1 :1 , preferably between 0:1 and 1 :1 , more preferably between 5:1 and 1 :1 , most preferably between 2:1 and 1 :1.

An especially expedient mixture for use as a bleaching agent comprises between 10 and 25 % by weight of phthalimido peroxyhexanoic acid (phthalimido percaproic acid, PAP) and between 2 and 5 % by weight of lactose based on the total weight of the mixture. Therefore, the present invention also relates to the mixture described above, characterized in that it comprises between 10 and 25 % by weight of phthalimido peroxyhexanoic acid (phthalimido percaproic acid, PAP) and between 2 and 5 % by weight of lactose based on the total weight of the mixture.

The mixture comprising the at least one phthalimido percarboxylic acid and the at least one disaccharide according to the present invention may be manufactured in the form of an aqueous solution, gel, emulsion, paste, dispersion, powder, flake, granules, scales, pearls, tablets, solid block form, extrudates and other forms known in the art, but preferably represents a powder or a flake.

Therefore, the present invention also relates to the mixture described above, characterized in that the mixture is in the form of a solid or a flake.

The mixture according to the present invention is particularly suitable as effective bleaching agent in detergent formulations.

Therefore, the present invention also relates to the use of a mixture described above as a bleaching agent.

The present invention further relates to a detergent composition comprising a mixture described above. The detergent composition may contain any additive or active ingredient commonly used in corresponding washing, cleansing and/or disinfecting agents like builders, surfactants, soaps, zeolites, hydrotropic agents, corrosion inhibitors, enzymes, optical brighteners, stabilizers, abrasives, perfumes, coloring agents.

The inventive mixture may be incorporated into the detergent composition either as such or in combination with further additives, for example phosphates, carbonates, zeolites, carboxymethylcellulose or filmbuilding agents like fatty acids, fatty acid amides or esters etc. in the forms mentioned above for the mixture.

In a preferred embodiment the detergent composition is substantially free of boric acid, i.e. comprises less than 10 ppm, preferably less than 5 ppm, even more preferably less than 1 ppm, and most preferably less than 0,1 ppm boric acid. Therefore, the present invention aiso relates to the detergent composition described before, characterized in that it comprises less than 10 ppm, preferably less than 5 ppm, even more preferably less than 1 ppm, and most preferably less than 0,1 ppm boric acid.

The detergent composition may be used as a laundry detergent, preferably as a textile detergent, and is not only suitable for generally washing laundry, but as well for disinfecting.

Besides, the detergent according to the present application may be used as cleanser and/or disinfectant for cleansing and disinfecting various kinds of hard surfaces like, for example, in the medicinal or institutional field, in the food preparing, processing and/or selling industry, in agriculture, in hotel business, catering trade and/or in public buildings and/or institutions. It may as well be useful in further applications in which a disinfected surface is required or desired and which are not explicitly mentioned herein. The surfaces supposed to become disinfected may be made of common materials mentioned in the state of the art like, for example, metal, glass, ceramic, plastic, (coated) wood.

Finally, the present invention relates to the use of at least one disaccharide for stabilizing a phthalimido percarboxylic acid in a detergent composition.

In the following, the stabilization of phthalimido peroxycarboxylic acids with disaccharides will be demonstrated without being restricted to these examples.

EXAMPLES

Example 1 :

A mixture for use as a bleaching agent comprising 86 % by weight of phthalimido peroxyhexanoic acid {phthalimido percaproic acid, PAP) and 14 % by weight of a stabilizing agent (example a: boric acid (comparative); example 1 b: glucose

(comparative); example 1c: maltodextrin (comparative); example 1d: lactose) was tested for its long-term stability. Therefore, the amount of chemically active PAP in the respective mixture was determined after storage by 40 °C at 1 , 3, 7, 14, 21 , 28, 49, 84, 1 9, 161 and 2 0 days, respectively. As can be taken from Table 1 , a mixture comprising lactose (example 1d) shows a significantly higher long-term stability of phthalimido peroxyhexanoic acid

(phthalimido percaproic acid, PAP) than a mixture comprising glucose (example 1 b) or maltodextrin (example 1 c).

Table 1 :

Moreover, as can be taken from Figure 2, phthalimido peroxyhexanoic acid

(phthalimido percaproic acid, PAP) can even more effectively be stabilized by a disaccharide according to the present invention (example 1d) than by boric acid conventionally used (example 1a).

Claims

1. Mixture for use as a bleaching agent comprising at least one phthalimido percarboxylic acid and at least one disaccharide.

2. Mixture according to claim 1 , characterized in that it comprises at least one reducing disaccharide.

3. Mixture according to claim 1 or 2, characterized in that it comprises at least one a non-reducing disaccharide.

4. Mixture according to any of claims 1 to 3, characterized in that it comprises at least one disaccharide selected from the group consisting of cellobiose, gentiobiose, isomaltose, isomaltuiose, lactose, lactulose, laminaribiose, maltose, maltulose, melibiose, neohesperidose, neotrehalose, nigeriose, rutinose, sophorose, saccharose, trehalose, and combinations thereof.

5. Mixture according to any of claims 1 to 4, characterized in that it comprises lactose.

6. Mixture according to any of claims 1 to 5, characterized in that it comprises at least one phthalimido percarboxylic acid selected from the phthalimido percarboxylic acids of the general formula (I)

where n is an integer of from 1 to 5.

7. Mixture according to any of claims 1 to 6, characterized in that it comprises phthalimido peroxyhexanoic acid.

8. ixture according to any of claims 1 to 7, characterized in that the content of disaccharide is between 1 and 50 % by weight, preferably between 1 and 25 % by weight, more preferably between 1 and 10 % by weight, most preferably between 2 and 5 % by weight based on the total weight of the mixture.

9. Mixture according to any of ciaims 1 to 8, characterized in that the weight ratio of phthalimido percarboxylic acid to disaccharide is between 20:1 and 1 :1 , preferably between 10:1 and 1 :1 , more preferably between 5:1 and 1 :1 , most preferably between 2:1 and 1 :1.

10. Mixture according to any of claims 1 to 9, characterized in that it comprises between 10 and 25 % by weight of phthalimido peroxyhexanoic acid

(phthalimido percaproic acid, PAP) and between 2 and 5 % by weight of lactose based on the total weight of the mixture.

11.Mixture according to any of claims 1 to 10, characterized in that the mixture is in the form of a powder or a flake.

12. Use of a mixture according to any of claims 1 to 11 as a bleaching agent.

13. Detergent composition comprising the mixture according to any of claims 1 to 11.

14. Detergent composition according to claim 13, characterized in that it

comprises less than 10 ppm, preferably less than 5 ppm, even more preferably less than 1 ppm, most preferably less than 0,1 ppm boric acid.

15. Use of at least one disaccharide for stabilizing a phthalimido percarboxylic acid in a detergent composition.