Bleach catalysts

Details Bleach catalysts Bleach catalysts

2000-12-19

2002-08-13

Delcotto, Gregory (Department: 1751)

Cleaning compositions for solid surfaces, auxiliary compositions

Cleaning compositions or processes of preparing

With oxygen or halogen containing chemical bleach or oxidant...

C510S302000, C510S303000, C510S309000, C510S312000, C510S314000, C510S372000, C510S508000

Reexamination Certificate

active

06432901

ABSTRACT:

This invention relates to activation of bleaches employing peroxy compounds, including hydrogen peroxide or a hydrogen peroxide adduct, which liberate hydrogen peroxide in aqueous solution, as well as peroxy acids; to compounds that activate or catalyse peroxy compounds; to bleach compositions including detergent bleach compositions which contain a catalyst for peroxy compounds; and to processes for bleaching and/or washing of substrates employing the aforementioned types of compositions.
In particular, the present invention is concerned with the novel use of transition metal compounds as improved catalyst for the bleach activation of peroxy compound bleaches.
Peroxide bleaching agents for use in laundering have been known for many years. Such agents are effective in removing stains, such as tea, fruit and wine stains, from clothing at or near boiling temperatures. The efficacy of peroxide bleaching agents drops off sharply at temperatures below 60° C.
Many transition metal ions catalyse the decomposition of H
2
O
2
and H
2
O
2
-liberating percompounds, such as sodium perborate. In practice, transition metal salts together with a chelating agent are used to activate peroxide compounds so as to make them usable for satisfactory bleaching at lower temperatures.
The catalysts of the invention may also be applied in the peroxide oxidation of a broad range of organic molecules such as olefins, alcohols, aromatic ethers, sulphoxides and various dyes, and also for inhibiting dye transfer in the laundering of fabrics.
EP-A-0 458 397 discloses transition metal bleach catalysts based on a non-cobalt metal and preferably comprises a manganese complex of formula (A):
[L
n
Mn
m
X
p
]
z
Y
q
  (A)
in which Mn is manganese, which can be either in the II, III, IV or V oxidation state, or mixtures thereof and wherein n and m are independent integers from 1-4; X represents a co-ordinating or bridging species, such as H
2
O, OH
−
, O
2−
, S
2−
, N
3−
, HOO
−
, O
2
2−
, O
2
1−
, R—COO
−
, with R being H, alkyl, aryl, optionally substituted, NR
3
with R being H, alkyl, aryl, optionally substituted, Cl
−
, SCN
−
, N
3
−
etc. or a combination thereof; p is an integer from 0-12, preferably from 3-6; Y is a counter-ion, the type of which is dependent on the charge z of the complex; z denotes the charge of the complex and is an integer which can be positive, zero or negative. If z is positive, Y is an anion, such as Cl
−
, Br
−
, l
−
, NO
3
, ClO
4
−
, NCS
−
, PF
6
−
, RSO
4
−
, OAc
−
, BPh
4
−
, CF
3
SO
3
−
, RSO
3
−
, RSO
4
−
etc; if z is negative, Y is a cation, such as an alkali metal, alkaline earth metal or (alkyl) ammonium cation etc; q=z/[charge Y]: and L is a ligand being a macrocyclic organic molecule of general formula (I):
wherein R
1
and R
2
can each be absent, H, alkyl, aryl, optionally substituted, each D can be independently N, NR, PR, O or S, wherein R is H, alkyl, aryl, optionally substituted. If D=N, one of the hetero-carbon bonds attached thereto will be unsaturated, giving rise to a —N=CR
1
-fragment, t and t′ are each independently 2 or 3, and s=2,3,4 or 5. These complexes are highly effective bleach catalysts. One preferred commercial example of a particular manganese complex of formula (A) is the complex of manganese in the (IV) oxidation state with 1,4,7-trimethyl-1,4,7-triazacyclononane (hereinafter referred to by the abbreviation Me
3
TACN), namely [Mn
IV
(&mgr;-O)
6
(Me
3
-TACN)
2
]— (PF
6
)
2
. The bleach catalysis activity of the free (uncomplexed) ligands of formula (I) is disclosed in EP-A-0 549 271, and for the same ligands in combination with water-soluble manganese salts is disclosed in EP-A-0 549 272.
However, if the bleaching activity of this class of materials could be boosted, they could be used at lower levels to provide a significant reduction in cost.
This problem has now been solved by formulating compositions comprising the same class of ligand as in formula (A), together with a water-insoluble compound of manganese.
The catalysts according to the present invention are also useful as oxidation catalyst systems and therefore find application in waste water treatment and in the general chemical industry.
Thus, the present invention now provides a bleach catalyst system comprising in combination, a macrocyclic organic ligand of formula (I):
wherein R
1
and R
2
can each independently be absent, H, alkyl or aryl, optionally substituted; t and t′ are each independent integers from 2-3; each D can independently be N, NR
3
, PR
3
, O or S, wherein each R
3
is independently H, alkyl or aryl, optionally substituted by one or more suitable substituents such as C
1-4
alkyl groups, or is a bridging group such as C
1-6
alkylene, either to another R
3
group in the same macrocycle or to another independently defined macrocyclic ligand of formula (I), wherein any bridging group optionally contains an optionally substituted heteroatom such as nitrogen; and s is an integer from 2-5; and a water-insoluble manganese compound.
The Ligand
In formula (I) R
1
and R
2
are preferably each zero, H, alkyl or aryl, optionally substituted; D and D′ are preferably each independently N, NR, PR, O or S, wherein R is H, alkyl or aryl, optionally substituted: t and t′ are each independently integers from 2-3; s is an integer from 2-4, and n=m=2. Especially preferred is when D is NR and t and t′ are 2 or 3, in particular when s is also 2. In the latter case, it is also most preferred for t and t′ both to be 2.
In the case of bridging by C
1-6
alkylene groups between R
3
groups of two or more ligands, preferably only two ligands are so bridged. One preferred bridged ligand of formula (I) is:
Other preferred sub-classes of the ligands of formula (I) are those in which D or D′ is NH or NR; t and t′ are 2 or 3, s=2, and R
1
=R
2
=H, more preferably, wherein D or D
1
is NCH
3
and t, t′=2, Me
3
—TACN is especially preferred.
Yet other preferred ligands are those stated in EP-A-0 458 397 as preferred.
Ligands of formula (I) may be prepared by any of the methods disclosed in EP-A-0 458 397.
The Manganese Compound
The term “water-insoluble manganese compound” as used herein, is intended to encompass manganese compounds which are generally considered truly water-insoluble as well as sparingly-soluble manganese compounds. Of course, no manganese compound has absolutely zero solubility. Thus, preferably, the term “water-insoluble” as used in reference to the manganese compound, preferably means that this compound has a solubility no more than 10 g/l, preferably no more than 5 g/l, still more preferably, no more than 2 g/l at 25° C.
Typical such compounds include those with hydr(oxide), carbonate, oxalate, sulphide and/or phosphate anions (“water-insoluble manganese compound” includes mixtures of two or more different such compounds).
Especially preferred are manganese oxides, for example, Mn
2
O
3
, Mn
3
O
4
and/or MnO
2
.
Any of the water-insoluble manganese compounds may be in any appropriate oxidation state for example the II, III or IV oxidation state.
The most preferred water-insoluble manganese compound is manganese dioxide. This material may exist in various forms and oxidation states. The term “manganese dioxide” as used herein is intended to cover any manganese dioxide material in one or more of these oxidation states and in pure or impure form. The different forms and oxidation states of manganese dioxide are disclosed in Gmelins Handbuch der anorganischen Chemie, System-Nummer 56, Teil C1, pages 127-156 (1973).
Generally speaking, the weight ratio of the ligand of formula (I) to the manganese compound is from 1:0.32 to 1:160, more preferably from 1:1 to 1:50, yet more preferably, from 1:3 to 1:16.
Compositions
The invention further extends to a bleaching composition comprising

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