CA2010271A1 - Metallo-porphyrins for use as bleach catalyst - Google Patents

Abstract

Abstract Metallo-porphyrins having improved stability against oxidation for use as peracid bleach catalyst in the bleaching of fabrics are disclosed. The metallo-porphyrins are Mn(III)- or Fe(III)-porphyrins having Ar-substituents on the meso-positions selected from (a) ; (b) and (c)

Description

2~ 7~.
C 7150 (R) ~ETALLO-PORPHYRINS FOR USE AS BLEACH CATALYST

This invention relates to improved metallo-porphyrins for use as a bleach catalyst in the bleaching of fabrics and to compositions for the cleaning and bleaching of fabrics comprising said metallo-porphyrins.

It is known that metallo-porphyrins can act as an oxidation catalyst. W0 88/07988 describes the use of metallo-porphyrins as catalyst in a variety of oxidative reactions. U.S~ Patent N 4,077,768 describes the use of lo iron-porphyrins with an oxidising bleach, e.g. hydrogen peroxide and al60 peracids, in aqueous wash li~uors for dye bleaching in solution, i.e. for inhibiting dye-transfer during the washing of fabrics. It i6 also known from EP-A-0306089 (published 8 March 1989) that metallo-porphyrins under careful conditions can effectivelycatalyse the fabric stain bleaching action of peroxyacid bleach systems, thereby making the peroxyacid more effective for use in the washing of fabrics at the lower temperature region of between about lO-C and 40C. A
drawback of metallo-porphyrins as bleach catalyst is that they are themselves unstable against oxidation by the oxidising bleach. Although the mode of action of metallo-porphyrin bleach catalysis is not fully understood, it appears that in the presence of an oxidising bleach the metallo-porphyrin catalyst forms an intermediate substance. This can react with substances able to be oxidised and bleached, whereby the catalyst is reformed, and this is the desired reaction. However, the intermediate substance can also react with a second metallo-porphyrin forming a dimeric -oxo bridged species which is ineffective as bleaching agent and quic~ly degrades under the oxidative conditions.
Reaction of the metallo-porphyrin with hydrogen peroxide, in the absence of a substrate, results in degradation via a different pathway in which radicals ~10~7~.
C 7150 (R) are believed to play a role. It is thus necessary that careful measures should be taken to avoid the metallo-porphyrins being oxidised. In the bleaching of fabrics with peroxyacids, the art teaches that metallo-porphyrins must be pre-adsorbed on to the fabric to exert their catalytic activity on stain bleaching. Even 80, some loss of catalyst due to decomposition, with consequent reduction of catalytic activity cannot be avoided.
The invention now provides improved metallo-porphyrins as peroxyacid bleach catalysts which are more stable against oxidation by mono oxygen donor type oxydators (like peroxyacids, hypochlorite and tert.butyl hydroperoxide), than the metallo-porphyrins suggested in the art for u~e in the bleaching of fabrics.

The metallo-porphyrins for use as peroxyacid bleach aatalyst in the bleaching o~ fabrics according to the invention are compounds having the follo~ing structural formula:

2 Ar 3 251 ~ ~ 4 ~ N ~ ,N ~
Ar ~ ,Me ~ Ar (I) 8 ~ 5 wherein Me is a metal ion, selected from Mn(III) and Fe(III); and Ar is a substituent selected from the group 2~ )h7 c 7150 (R) consisting of Xl X
~=~ (B)n-(A)m >=~
(a) ~ : (b) ~ N+ - (B)n~(A)m and X
>~
(c) ~ ~(CH2)n - N - (B)3 wherein n and m may be 0 or 1; A may be sulphate, sulphonate, phosphate or carboxylate groups; B is Cl-C10 alkyl, polyethoxy alkyl or hydroxy alkyl and Xl and X2 are Cl, Br, CH3, C2H5 or CH30.

Although not es6ential, the porphyrin core formula (I) may be substituted at one or more o~ the remaining carbon positions indicated by the numbers 1-8, with e.g.
Cl-C10 alkyl, hydroxy alkyl or oxyalkyl groups.

The phenyl or pyridyl group (a), (b) or (c) may or may not contain other 6ubstituent~, but it has been found that improved 6tability is only achieved if the Xl and X2 ~ubstituent6 are attached on the phenyl or pyridyl group at exactly the indicated places near the porphine core. Xl and X2 substituents attached on other places of the phenyl or pyridyl group such as:

(B)n~(A)m ~ ~
~ or ~ N - (B)n~(A)m have no effect on stability whatsoever.

2~ 71 C 7150 (R) Preferred molecules are those in which the -(B)n-(A)m substituents on the phenyl or pyridyl groups are selected from:

-~H3 ; -C2Hs ; -CH2-cH2-cH2-sO3 -CH2CH(OH)CH2SO3- and -SO3-.

Preferably Xl and X2 are Cl, Br or CH3, particularly Cl or CH3.
Typical examples of preferred Fe(III) and Mn(III) porphyrins are thus compounds wherein the Ar-substituents are:

Cl so-3 CH3 SO-3 ~ >=< ' ' ; ~ - CH3 Cl . CH3 Cl CH3 ~ N+ - CH3 ; ~ N+ - CH3 25 Cl CH3 Cl CH3 - CH2 - ~ - CH3 ; ~ -N+ - C2H5 Cl CH3 The metallo-porphyrins of the invention can be used as a catalyst for peroxyacids or peroxyacid salts for the bleaching of fabrics in the same manner as applied with the known metallo-porphyrins of the art, but it can easily be appreciated that the improved stability 2a~ 7'!

C 7150 (R) thereof will result in a more effective and efficient use of the catalyst.

A common process of using metallo-porphyrins as catalyst in the bleaching and cleaning of fabrics with peroxy acid or a peroxyacid salt is by treating the fabrics with the metallo-porphyrin compound, leaving the fabric in contact therewith for a predetermined time to effect sufficient adsorption of said compound on to the fabric, lo and thereafter washing the fabric with a peroxyacid bleach composition. The fabrics may be treated in a bath comprising an effective amount of a dissolved or solubilised metallo-porphyrin (normally in the range of 2 to 25 ppm) for several minutes, to which bath is then added a peroxyacid bleaching agent in an amount sufficient to effect the required bleaching effect tnormally at a level of about 20-1000 ppm). The amount of solubilised or dissolved metallo-porphyrin in the bath and also the amount of~peroxyacid bleach added thereto will depend upon the fabric wash load and the rate of staining, the adjustment thereof being within the ability of the skilled artisan.

An alternative way of pretreating the fabrics is by manual application on to the fabric on places with stubborn and persistent stains, and leaving the fabric treated therewith for a couple of minutes, whereafter the fabric is washed in a conventional manner with a peroxyacid bleach composition.
It should be appreciated that the fabrics which are treated in a bath comprising a dissolved or solubilised metallo-porphyrin may, or may not, have been manually pretreated with metallo-porphyrin as is deemed necessary.

The peroxyacids, the activity of which can be catalysed 2G~)27l.

C 7150 (R) by the metallo-porphyrins of the invention, include any organic peroxyacids and inorganic peroxyacid salts.

Examples of 6uch organic peroxyacids can be represented by compounds of the general formula:
P, HO-O-C-(O)n-R-Y
wherein R is an alkylene or substituted al~ylene group containing 1 to 20 carbon atoms or an arylene group containing from 6 to 8 carbon atoms, n i6 0 or 1, and Y
is hydrogen, halogen, alkyl, aryl or any group which provides an anionic moiety in aqueous solution. Such groups can include, for example:
O O O
-C-OM ; -C-O-OM or -S-OM
wherein M is H or a water-soluble, salt-forming cation.

The organic peroxyacid~ and salts thereof can contain either one, two or more peroxy groups and can be either aliphatic or aromatic. When the organic peroxyacid is aliphatic, the unsubstituted acid may have the general formula:
u HO-O-C-(O)n~(CH2)m~Y
O O
wherein Y can be H, -CH3, -CH2Cl, -C-O-M, C-O-OM

or -S-OM, O
and m can be an integer from 1 to 20.
.

Specific examples o~ compounds of this type are peracetic acid, perlauric acid and diperoxydodecanedioic acid.

When the organic peroxyacid is aromatic, the 2~10~71.
C 7150 (R) unsubstituted acid may have the general formula:
o HO-O-c- () n~C6H4~Y
wherein Y is, for example, hydrogen, halogen, alkyl, O O O
1~ 11 11 -C-QM, -C-O-OM or -S-OM.

The percarboxy or percarbonic and Y groupings can be in any relative position around the aromatic ring. The ring and/or Y group (if alkyl) can contain any non-interfering substituents, 6uch as halogen or sulphonate groups.

Specific examples of such aromatic peroxyacids and salts thereof include peroxybenzoic acid, m-chloro-peroxybenzoic acid, p-nitro-peroxybenzoic acid, p-sulphonato-peroxybenzoic acid, diperoxyisophthalic acid and peroxy-alpha-napthoic acid.

A specific example of inorgan~c peroxyacid salts is potassium monopersulphate. A product comprising this compound i5 the triple salt, K2S04.KHSO4.2KHSO5, available commercially under the trade-name Oxone R from E.I. Dupont de Nemours and Company.
Accordingly, the invention provides the use of a metallo-porphyrin of structural formula (I), as defined herein above, as a bleach c~talyst for the bleaching of fabrics with a peroxyacid bleach ~ystem.
The invention also provides a fabric washing product comprising a detergent active-material, a peroxyacid bleach and said metallo-porphyrin as catalyst therefor.

Fabric washing products according to the invention may be presented in any form, including that of a packages washing powder comprising the metallo-porphyrin 2~ 71.
C 7150 (R) catalyst, together with a separate pack of ona-wash peroxyacid containing sachets.

Alternatively, the product can be in the form of a sachet within a sachet, the inner sachet containing a peroxyacid and being provided by means of a delaying release of the contents, and the outer sachet containing a washing composition comprising the metallo porphyrin catalyst and releasing its contents fairly rapidly upon immersion in water.

Another product form is for example that of a washing powder compri6ing a peroxyacid and the metallo-porphyrin catalyst in which the peroxyacid is provided in the form of coherently coated particles. Still other product forms are feasible and those skilled in the art will have no difficulty in selecting product forms by means of existing technology.

In another embodiment, the invention provides a pretreatment product for local application on to fabrics, textiles and clothes, consisting essentially of a liquid or paste-like composition comprising a dispersion or solution of a metallo-porphyrin as defined herein in a 6uitable liquid or semi-liquid carrier, presented in a suitable di6penser for manual application of any known form of applicators, such as an aerosol pres~ure container, pump-spray bottle, roller-ball capped bottle, pad applicators and the like.
In such applicators the liquid carrier will also contain a volatile solvent which evaporates upon application, leaving the metallo-porphyrin firmly attached on to the fabric surface to absorb. An example of a suitable carrier is a mixture of a nonionic surfactant and a lower alcohol, e.g. methanol.

Compositions compri6in~ the metallo-porphyrins of the 2G~O~
C 7150 tR) invention dispersed in a carrier of this type are typical for roller-ball capped bottle and pad applicators. Liquid or paste-like compositions for use in a pretreatment product may contain from about 0.1-1.0 g/l metallo~porphyrin, usually from about 0.2-0.5 g/l.

The treating bath as well as the washing composition comprising the metallo-porphyrin catalyst can contain any of the usual components of detergent compositions in the usual amounts. Thus organic detergent-active materials of the anionic, nonionic, zwitterionic and cationic types and mixtures thereof can be present, in an amount from about 3 to about 40% by weight.

Suitable detergent-actives are well known in the art and examples of such suitable compounds commonly used in the art are given in "Surface Active Agents", Vol. I, by Schwartz and Perry (Interscience 1949) and "Surface Active Agents", Vol. II, by Schwartz, Perry and Berch ~Interscience 1958).

Detergency builders, whether inorganic or organic, phosphate or non-phosphate, water-soluble or insoluble, and other water-soluble salts and buffering agents may preferably also be present. In addition thereto the washing composition may contain any other non-interfering ingredients normally used in detergent compositions in minor amounts, which serve to improve the bleaching and laundering characteristics of the composition or which add aesthetic appeal to the composition. Such minor ingredients can include sequestering agents and co-builders (e.g. homo- and co-polymers); suds control agents; soil-suspending agents and anti-redeposition agents; enzymes, particularly proteolytic and lipolytic enzymes; corrosion inhibitors, optical brightening agents, colouring agents, perfumes, clays and fillers.

2G10~7~
C 7150 (R) Fabric washing compositions usable in the present invention may contain from about 3 to about 40% by weight of organic detergent active material, 0 to 60%, preferably from 5 to about 40% by weight of detergency builder, from about 1 to 10% by weight of peroxyacid, and from about 0.05 to 1.0% by weight of metallo-porphyrin. They are usable normally at a dosage of 2-10 g/l for washing fabrics at wash loads of about 4-5 kg.
The i~vention will now be illustrated by way of the following non-limiting examples.

2G1~27~
C 7150 (R) Example I

Preparation of metallo-porphyrins according to the invention.

(i) Tetrakis-(2,4,6-trimethyl-3-sulphonatophenyl)-porphyrinato-Mn(III)oH4- (Na~)4 To 2.14 g pyrrole (0.02 mol) and 2.96 g 2,4,6-trimethyl-lo benzaldehyde solved in 3 1 dichloromethane (dry) i6 added 0.5 ml of boron trifluoride-etherate. After 24 h stirring under argon in the dark, the mixture is refluxed for 30 minutes in the presence of 15 g chloranil (0.06 mol). The mixture is concentrated and chromatographed on alumina with chloroform as eluent.
The porphyrin-containing fractionc are pooled and evaporated. From the residue the tetrakis-(2,4,6-trimethyl phenyl) porphyrin is obtained by crystallisation from hexane. Treatment of this porphyrin with concentrated sulphuric acid yields the tetrakis-(2,4,6-trimethyl-3-sulphonato)-porphyrin as its four atropisomers. Stirring the latter in aqueous Mn-acetate (lM), subsequent treatment with ion exchanger (Dowex 50 W-H-form) and final neutralisation yields the compound (i) which is further purified by chromatography on a Sephadex L H-20 column in methanol and obtained in a yield of 0.8 gram (20%).

The system is characterised by its W/VIS, IR and FAB-massespeatrometry.

(ii) ~etrakis-(2,4,6-trimethyl-3-sulphonatophenyl)-porphyrinato-Fe(III)OH4~ (Na+)4 This system was prepared in a manner similar to that as described for (i) above, except that now metalation was 2Gl~)271.

C 7150 (R) performed using FeS04, ~iving the compound (ii) in a 0.3 gram (7%) yield, similary characterised as described for the manganese porphyrin.

Exam~le II

The oxidation stability of the substituted mangano-porphyrin of Example I (i) (TMP4-) against potassium monopersulphate (HS05-) and peracetic acid (per-Ac) was determined and compared with a non-substituted mangano-porphyrin (TPP4-).
Ar-substituents:

CH3 S03- so3 (TMP4 ) = ~ CH3- (TPP4-) =

Stabilities were measured by means of a UV/VIS
spactroscopic method in the absence of a substrate at cat~lyst concentration of 10-6 mol/l.

The resu}ts are tabulated below.
Table 1 Stabilitv values from tests with HS05-(3.8 x 10-3 mol/l) Time (min.) 0 4 8 15 30 60 T ~
TMP4 100 96 92 89 83 75 120.0 minutes TPP4- 100 63 33 18 - - 5.5 minutes Table 2 StabilitY values from tests with Per-Ac (2.4 x 10-3 mol/l) Time (min.) 0 5 10 30 T ~
TMP4- 100 96 94 91 150.0 minutes TPP4- 100 30 15 - 2.0 minutes C 7150 (R) From the above tables it is clearly seen that TMP4 of the invention is more stable than TPP4- of the art against peracetic acid and potassium monopersulphate. In terms of hal~-life time, TMP4- is about 20 times more stable against HS05- and about 75 times more stable against peracetic acid than TPP4-.

.

'

Claims (10)

1. Use as a peroxyacid bleach catalyst in the bleaching of fabrics of a metallo-porphyrin having the following structural formula:

(I) wherein Me is a metal ion, selected from Mn(III) and Fe (III); Ar is a substituent selected from the groups consisting of (a) ; (b) and (c) wherein n and m may be 0 or 1; A may be sulphate, sulphonate, phosphate or carboxylate groups; B is C1-C10 alkyl, polyethoxy alkyl or hydroxy alkyl and X1 and X2 are Cl, Br, CH3, C2H5 or CH3O.

2. Use according to claim 1, characterized in that the -(B)m-(A)m substituent is selected form -CH3; -C2H5;

C 7150 (R) -CH2-CH2-CH2-SO3-; CH2-CH(OH)-CH2-SO3- and SO3-.

3. Use according to claim 1 or 2, characterized in that X1 and X2 are Cl, Br or CH3.

4. A fabric washing composition comprising a detergent active material, a peroxyacid bleach and a metallo-porphyrin having the structural formula (I) of claim 1.

5. A fabric washing according to claim 4;
characterized in that the -(B)n-(A)m substituent is selected from -CH3; -C2H5; CH2-CH2-CH2-SO3-; CH2-CH(OH)-CH2-SO3-; and SO3-.

6. A fabric washing composition according to claim 4 or 5, characterized in that X1 and X2 are Cl, Br of CH3.

7. A pretreatment product for local application on to fabrics, textiles and clothes, consisting essentially of a liquid or paste-like composition comprising a dispersion or solution of a metallo-porphyrin having structural formula (I) of claim 1, in a suitable liquid or semi-liquid carrier, presented in a suitable dispenser for manual application.

8. A pretreatment product according to claim 7, characterized in that the -(B)n-(A)m substituent is selected form -CH3; -C2H5; CH2-CH2-CH2-SO3-; CH2-CH(OH)-CH2-SO3- and SO3-.

9. A pretreatment product according to claim 7 or 8, characterized in that X1 and X2 are Cl, Br or CH3.

10. The use as a peroxyacid bleach catalyst in the bleaching of fabrics as claimed in claim 1 and substantially as described herein.