EP1833956B1

EP1833956B1 - Dispensing system

Info

Publication number: EP1833956B1
Application number: EP05796209A
Authority: EP
Inventors: Andrew Timothy Unilever R & D Port Sunlight HIGHT; Vidyadhar Sudhir Unilever R & D Vlaardingen RANADE
Original assignee: Unilever PLC; Unilever NV
Current assignee: Unilever PLC; Unilever NV
Priority date: 2004-11-19
Filing date: 2005-10-12
Publication date: 2012-07-11
Anticipated expiration: 2025-10-12
Also published as: WO2006053614A2; WO2006053614A3; ES2391279T3; GB0425467D0; EP1833956A2

Abstract

A laundry fluid comprising capsules containing a bleach catalyst and contained in a dispensing device, the dispensing device comprising: a. a reservoir containing the laundry fluid, each of the principal dimensions of the reservoir being greater than the average diameter of the capsules, b. a dispensing outlet in fluid communication with the reservoir and having, in at least one part, a rupture diameter which is less than the average diameter of the capsules; wherein the laundry fluid is dispensed from the reservoir by forcing the laundry fluid to egress via the dispensing outlet, and the passage of capsules through the dispensing outlet ruptures the capsules, thereby releasing the bleach catalyst as the laundry fluid is dispensed.

Description

The present invention relates to a dispensing system comprising a dispensing device and a fluid laundry composition comprising an encapsulated bleach catalyst contained in a dispensing device.
Laundry compositions comprising bleaches are known (see GB e.g. 2267911 and US 5747441 ). Bleaches are used to remove stains from fabrics.
In a first aspect, the invention provides a dispensing system comprising a dispensing device and a laundry fluid comprising capsules containing a bleach catalyst, contained in a dispensing device, the dispensing device comprising:

1. a reservoir containing the laundry fluid, each of the principal dimensions of the reservoir being greater than the average diameter of the capsules,
2. a dispensing outlet in fluid communication with the reservoir and having, in at least one part, a rupture diameter which is less than the average diameter of the capsules;

In a further aspect the invention provides a method of dispensing a laundry fluid comprising capsules containing a bleach catalyst, by employing the device of the first aspect of the invention to dispense the fluid and released bleach catalyst e.g. into a washing machine draw, dosing device.
In a further aspect the invention provides a method of pretreating a fabric with a laundry bleach catalyst, by employing the device of the first aspect of the invention to dispense the fluid and released bleach catalyst directly on to the fabric.
In a further aspect the invention provides a method of directly bleaching a fabric, by employing the device of the first aspect of the invention to dispense the fluid and released bleach catalyst directly on to the fabric.
This method may be part of a pre-treating method, that is pre-treating a fabric prior to a subsequent washing operation e.g. a wash cycle carried out in an automatic washing machine.
In a further aspect the invention provides a method of washing a fabric or treating a fabric, the method comprising dispensing a laundry fluid comprising capsules containing a bleach catalyst from the device of the first aspect of the invention and applying to the fabric.
With this arrangement, the bleach catalyst is protected from the naturally occurring process of autoxidation of organic components within the fluid produces alkylhydroperoxides which, over time (e.g. during transport, storage) interact with the bleach catalyst. Thus, bleach performance can be maintained until such time as the consumer is ready to use the product.
The invention provides a relatively inexpensive dispensing system, in terms of financial and environmental cost in what can be an uncomplicated device which can be used so long as the dispensing outlet is dimensioned relative to the capsule size.
Advantageously, capsules can be made very strong to withstand high forces imposed by storage and transport. The extra force to rupture is conveniently provided precisely at the time of dispensing, by means of compression in an outlet conduit so that the active material is released only when required. This allows fine tuning of the capsule properties to enhance strength without risking poor delivery and performance due to lack of capsule rupture.
As used herein, the term 'fluid' is intended to include a liquid, gel or paste, but excludes dry powder formats.
The fluid may be formulated to provide a suspension of the capsules in it, so as to enable uniform dosage, if desired.
The term "principal dimensions" is intended to include those parameters generally necessary for measurement of a three dimensional space. In the case of a generally rectangular or square body, the principal dimensions are width, depth, height; whereas with standard the case of a spherical reservoir, the diameter will be principal dimension. Typically, capsules to be carried by a liquid will be generally spherical. For non-uniform capsule shapes the greater dimension would be the relevant one. E.g. for an ellipsoids capsule, the greater diameter.
The dispensing outlet may be a single or multiple nozzle arrangement whereby the diameter/s of the nozzle/s tapers (i.e. gradually) reduces in the direction of the exit, at which point, rupture diameter is reached. This provides the advantage that rupture occurs only at the point of exit.
The dispensing outlet may comprise one or more sections of constant diameter upstream (or even downstream) of part having the rupture diameter. This has the advantage that the capsules are ruptured progressively as they move along the section/s of constant diameter.
The dispensing outlet may comprise multiple successive, conduits each having one or more sections of rupture diameter for progressive rupture of the capsules e.g. if they are in high concentration. Such sections may each be separated by a section of higher diameter which may be constant or tapered along the length.
There may be multiple conduits within the dispensing outlet each having one or more sections with a rupture diameter as described above. Multiple conduits are advantageous for example if a relatively high dosage (which may be 30-100 ml for main wash laundry purposes) is needed to be dispensed for a single use.
The largest diameter of the conduit through which the fluid flows may correspond to rupture diameter. The encapsulates are then extended just before the nozzle so that they are ruptured and open to discharge the bleach encapsulate just before they exit from the outlet, along with the liquid/gel/paste into the surroundings.
The fluid may be forced out of the reservoir by any suitable means, for example, it may forced out by compressing the reservoir. To this end, the reservoir preferably is, in whole or in part, compressible. To this end the reservoir may be in whole or part flexible to allow squeezing. The reservoir may also be, in whole or in part, resilient such that once the compressive force is removed, the reservoir expands again, so as to relieve pressure on its contents thereby enhancing integrity of stored capsules.
Preferably the material to be encapsulated is present in less than 10% of the total formulation amount. This allows for effective rupture.

THE BLEACH CATALYST

The bleach catalyst may comprise selected transition metal catalysts in the absence of an added peroxyl source, i.e., where the bleaching composition is substantially devoid of a peroxygen bleach or a peroxy-based or peroxyl-generating bleach system.
The term "substantially devoid of a peroxygen bleach or a peroxy-based or peroxyl-generating bleach system" should be construed within spirit of the invention. It is preferred that the composition has as low a content of peroxyl species present as possible. It is preferred that the bleaching formulation contains less that 1 % wt/wt total concentration of peracid or hydrogen peroxide or source thereof, preferably the bleaching formulation contains less that 0.3 % wt/wt total concentration of peracid or hydrogen peroxide or source thereof, most preferably the bleaching composition is devoid of peracid or hydrogen peroxide or source thereof.
In addition, it is preferred that the presence of alkyl hydroperoxides are kept to a minimum in the bleaching composition.
We have concluded from our research that bleaching of a chromophore in an oily stain is effected by products formed by adventitious oxidation of components in the oily stain. These products, alkyl hydroperoxides, are generated naturally by autoxidation of the oily stain and the alkyl hydroperoxides together with a transition metal catalyst serve to bleach chromophores in the oily stain. Alkyl hydroperoxides (ROOH) are generally less reactive that other peroxy species, for example, peracids (RC(O)OOH), hydrogen peroxide (H2O2), percarbonates and perborates. In this regard, the phrase "for bleaching a substrate with atmospheric oxygen" is synonymous with "for bleaching a substrate via atmospheric oxygen" because it is the oxygen in the air that provides the bleaching species used by catalyst to bleach the substrate stain.
The bleach catalyst per se may be selected from a wide range of transition metal complexes of organic molecules (ligands). In typical washing compositions the level of the organic substance is such that the in-use level is from 0.05 µM to 50 mM, with preferred in-use levels for domestic laundry operations falling in the range 1 to 100 µM. Higher levels may be desired and applied in industrial textile bleaching processes. A mixture of different catalysts may be employed in the bleaching composition.
Suitable organic molecules (ligands) for forming complexes and complexes thereof are found, for example in:

GB 9906474.3 ; GB 9907714.1 ; GB 98309168.7 , GB 98309169.5 ;
GB 9027415.0 and GB 9907713.3 ; DE 19755493 ; EP 999050 ;
W09534628 ; EP-A-458379 ; EP 0909809 ; United States Patent 4,728,455 ; WO9839098 ; WO9839406 , W09748787 , WO0029537 ;
W00052124 , and W00060045 the complexes and organic molecule (ligand) precursors of which are herein incorporated by reference. An example of a preferred catalyst is a transition metal complex of MeN4Py ligand (N,N-bis(pyridin-2-yl-methyl)-1,1-bis(pyridin-2-yl)-1-aminoethane).

The ligand forms a complex with one or more transition metals, in the latter case for example as a dinuclear complex. Suitable transition metals include for example: manganese in oxidation states II-V, iron II-V, copper I-III, cobalt I-III, titanium II-IV, tungsten IV-VI, vanadium II-V and molybdenum II-VI.
An example of a preferred catalyst is a monomer ligand or transition metal catalyst thereof of a ligand having the formula (I):
wherein each R is independently selected from: hydrogen, F, Cl, Br, hydroxyl, C1-C4-alkylO-, -NH-CO-H, -NH-CO-C1-C4-alkyl, -NH2, -NH-C1-C4-alkyl, and C1-C4-alkyl;
R1 and R2 are independently selected from:
C1-C4-alkyl,
C6-C10-aryl, and,
a group containing a heteroatom capable of co-ordinating to a transition metal, wherein at least one of R1 and R2 is the group containing the heteroatom;
R3 and R4 are independently selected from hydrogen, C1-C8 alkyl, C1-C8-alkyl-O-C1-C8-alkyl, C1-C8-alkyl-O-C6-C10-aryl, C6-C10-aryl, C1-C8-hydroxyalkyl, and -(CH2)_nC(O)OR5
wherein R5 is independently selected from: hydrogen, C1-C4-alkyl, n is from 0 to 4, and mixtures thereof; and,
X is selected from C=O, -[C(R6)₂]_y- wherein Y is from 0 to 3 each R6 is independently selected from hydrogen, hydroxyl, C1-C4-alkoxy and C1-C4-alkyl.
With regard to the above formula (I) it is also particularly preferred that R1 and R2 may also be independently selected from: C1 to C22-optionally substituted alkyl, and an optionally substituted tertiary amine of the form -C2-C4-alkyl-NR7R8, in which R7 and R8 are independently selected from the group consisting of straight chain, branched or cyclo C1-C12 alkyl, benzyl, the -C2-C4-alkyl- of the -C2-C4-alkyl-NR7R8 may be substituted by 1 to 4 C1-C2-alkyl, or may form part of a C3 to C6 alkyl ring, and in which R7 and R8 may together form a saturated ring containing one or more other heteroatoms.
Another preferred class of ligands are macropolycyclic rigid ligands of the formula:
wherein m and n are 0 or integers from 1 to 2, p is an integer from 1 to 6, preferably m and n are both 0 or both 1 (preferably both 1), or m is 0 and n is at least 1; and p is 1; and A is a nonhydrogen moiety preferably having no aromatic content; more particularly each A can vary independently and is preferably selected from methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, C5-C20 alkyl, and one, but not both, of the A moieties is benzyl, and combinations thereof.
Preferably, the macropolycyclic ligand is of the formula:
wherein "R¹" is independently selected from H, and linear or branched, substituted or unsubstituted C1-C20 alkyl, alkylaryl, alkenyl or alkynyl; and all nitrogen atoms in the macropolycyclic rings are co-ordinated with the transition metal.
Of the macropolycyclic ligands 5,12-dimethyl-1,5,8,12-tetraaza-bicyclo[6.6.2]hexadecane is preferred. This ligand is most preferred as its manganese complex [Mn(Bcyclam)Cl₂] and may be synthesised according to WO9839098 .
The transition metal complex preferably is of the general formula (AI):

[M_aL_kX_n] Y_m

in which:

M represents a metal selected from Mn(II)-(III)-(IV)-(V), Cu(I)-(II)-(III), Fe (II)-(III)-(IV)-(V), Co(I)-(II)-(III), Ti(II)-(III)-(IV), V(II)-(III)-(IV)-(V), Mo(II)-(III)-(IV)-(V)-(VI) and W(IV)-(V)-(VI), preferably from Fe(II)-(III)-(IV)-(V);
L represents the ligand, preferably N,N-bis(pyridin-2-yl-methyl)-1,1-bis(pyridin-2-yl)-1-aminoethane, or its protonated or deprotonated analogue;
X represents a coordinating species selected from any mono, bi or tri charged anions and any neutral molecules able to co-ordinate the metal in a mono, bi or tridentate manner;
Y represents any non-coordinated counter ion;
a represents an integer from 1 to 10;
k represents an integer from 1 to 10;
n represents zero or an integer from 1 to 10;
m represents zero or an integer from 1 to 20.

Several types of encapsulates can be used but the most useful are ` core in shell' type of encapsulates typically ranging from 100 micrometer to 10 mm in size.
Various non-limiting embodiments of the invention will now be more particularly described with reference to the following figure in which:

Figure 1 shows a perspective view of a system according to one aspect of the invention.

Referring to the figure, a system a fluid dispensing system for dispensing a laundry gel comprising capsules containing a bleach catalyst.
The dispensing system 1 comprises a container 3 having a reservoir 5 for storing a laundry gel 50, the reservoir 3 having all principal dimensions (height,width,depth)7,9,11 greater than the average diameter of the capsules 13 so as to retain integrity of capsules 13 when stored within the reservoir 5.
The system comprises a dispensing outlet referred to generally at 15. This outlet is in fluid communication with the reservoir 5 and comprises a single conduit 17.
The conduit has what is diameter 19 which is less than the average diameter of the capsules 13. This diameter is referred to as the rupture diameter.
The dispensing outlet 15 is structured so that the largest diameter of the conduit 17 available for gel flow of the nozzle corresponds to rupture diameter 19 i.e. it is smaller than the diameter of the capsules to be ruptured. In this example the rupture diameter (which is an internal diameter) is 1.0 mm and this is smaller than average outer diameter of the capsules.
The reservoir 5 is a flexible plastic and to enable the gel 50 to be forced out of the reservoir by compression by the user by hand. The reservoir 5 may also be resilient allowing it to revert to its original, uncompressed state following squeezing so as to relieve pressure on its contents thereby enhancing integrity of stored capsules 13.
In use, dispensing is achieved by forcing the gel 50 to exit the reservoir 5 and the dispensing outlet 15, where the rupture diameter 19 of the conduit 17 shears and ruptures the capsules being forced through the conduit 17, thereby releasing the perfume material contained within the capsule, upon gel dispensing. Hence the perfume is protected by the capsule until dispensing when it is released for optimal sensory effect.

Laundry Gel and Capsules formulation and Preparation

The laundry gel of this embodiment is used to enable to suspend capsules or 'beads' for uniform dosage. The gel/capsule mix has the following formulation:
The bleach catalyst-filled capsules are prepared as follows:

2g of octylsilane modified fumeed silica e.g. R805 fumed silica from Degussa. was added to 100ml of polydimethylsiloxane polymer e.g. AK1000 PDMS oil from Wacker with a viscosity of 1000cP and the mixture ultraturraxed for 5 minutes until the mixture was completely homogenous. 2g of catalyst in powder form (average particle size in the catalyst powder was 9 micrometer) was then added to this mixture and once again the mixture ultraturraxed for 5 minutes. The catalyst particles remain dispersed and suspended in the structure oil matrix. This oil is added to an arabic gum and gelatin mixture.

Arabic gum and gelatin mixture

A two-polymer material complex is used, namely arabic gum and gelatin. The method involves placing into a two litre beaker, the following:

700ml of water
180 ml gelatin aqueous solution - 2% by weight
180 ml gum arabic aqueous solution - 2 % by weight.

With the system adjusted to 40-45 degrees C and pH adjusted to 4.5.
100g of the silicone oil mix is introduced to the arabic gum-gelatin solution optionally with non-ionic emulsifier added to it ***PERHAPS WE CAN SAY EXPLICITLY WHAT THE ADVANTAGE OF THIS WOULD BE: "to improve emulsification of the oil which ....."?), with constant stirring, over a period of an hour. The resultant capsules are hardened with the addition of 10ml of a 25 % by wt aqueous solution of glutaraldehyde, accompanied by stirring for 1-20 hours during which the temperature is allowed to rise to the ambient room temperature.
(The capsules can be recovered from this vehicle by decantation or filtering, accompanied by drying in an air blast or by sifting with an adsorbent material such as starch or diatomaceous earth, and afterwards cleaned by repeated washings in a highly evaporable liquid medium.)
In this case, 1g of the coacervates mixture, containing the capsules of bleach catalyst (without the capsules having been separated from the vehicle) is then mixed in 80g laundry gel of composition described below.

Gel properties

Gel rest viscosity of 1000 Pa.s
Gel pour (shear rate 20 s^-1) viscosity of 1 Pa.s

Gel formulation
LAS acid	8.9%
Ethoxylated alcohol (Neodol 25-9)	6.5%
Borax	2.3%
MPG	1.5%
Sorbitol	2.0%
NaOH (50%)	1.1%
Isodecyl alcohol (EXXAL 10)	3.5%
Minors	1%
Balance	water

Bleach Cataylst

There are many transition metal catalysts or ligands thereof that may be incorporated inside the coacevate. The following are specific preferred but non-limiting transition metal catalysts that may be used. Beside each specific catalyst in parenthesis is a reference to a patent that describes the generic class thereof, in addition to others found therein, that are also applicable for use with the present invention: dimethyl 3,7-dimethyl-9-oxo-2,4-bis(pyridyl)-3,7-diazabicyclo[3.3.1]nonane-1,5-dicarboxylate ( WO0248301 ); 5,12-dimethyl-1,5,8,12-tetraaza-bicyclo[6.6.2]hexadecane ( WO0029537 ); N,N-bis(pyridin- 2-yl-methyl)-1,1-bis(pyridin-2-yl)-1-aminoethane ( WO0012667 ); and, (dimethyl 2,4-di-(2-pyridyl)-3-methyl-7-(N,N-dimethylaminoethylene)-3,7-diaza-bicyclo[3.3.1]nonan-9-one-1,5-dicarboxylate) ( WO03104378 ).
Whilst the above will bleach in what is known as an air mode, encapsulation affords the opportunity of incorporating a peroxyl species in liquid medium. Peroxyl species would de-stablise the bleach catalyst however, because the catalyst is segregated from the liquid by encapsulation the catalyst is protected. Examples of peroxyl are sodium percarbonate and peracids, e.g.,
N,N-phthaloylaminoperoxycaproic acid PAP.
With the above arrangement, the laundry capsules can be made sufficiently strong to withstand forces imposed by storage and transport. The extra force to rupture is conveniently provided precisely at the time of dispensing, by means of compression at (or in) an outlet conduit so that the active material is released only when required. This allows fine tuning of the capsule properties to enhance strength without risking poor delivery of bleach and poor bleach performance due to lack of capsule rupture.

Claims

A dispensing system comprising a dispensing device and a laundry fluid, the laundry fluid comprising capsules containing a bleach catalyst and contained in the dispensing device; the dispensing device comprising:
a. a reservoir containing the laundry fluid, each of the principal dimensions of the reservoir being greater than the average diameter of the capsule,

b. a dispensing outlet in fluid communication with the reservoir and having, in at least one part, a rupture diameter which is less than the average diameter of the capsules;
the laundry fluid being dispensed from the reservoir by forcing the laundry fluid to egress via the dispensing outlet, and the passage of capsules through the dispensing outlet ruptures the capsules, thereby releasing the bleach catalyst as the laundry fluid is dispensed.
A dispensing system according to claim 1 the fluid being a liquid, gel or paste.
A dispensing system according to any preceding claim wherein the dispensing outlet comprises one or more conduits.
A dispensing system according to any preceding claim wherein the diameter of the oulet tapers in the direction of the egress of fluid, terminating in the rupture diameter.
A dispensing system according to any preceding claim wherein the dispensing outlet comprises one or more sections of constant diameter.
A dispensing system according to any preceding claim wherein the dispensing outlet comprises multiple, successive conduits having rupture diameter.
A dispensing system according to any preceding claim wherein the capsules are 'core in shell' type.
A dispensing system according to any preceding claim wherein the capsules range from 100 micrometer to 10 mm in diameter.
A method of dispensing a laundry fluid comprising capsules containing a bleach catalyst, by employing the dispensing device of claim 1 to dispense the fluid and released bleach catalyst e.g. into a washing machine draw, dosing device.
A method of pretreating a fabric with a laundry bleach catalyst, by employing the dispensing device of claim 1 to dispense the fluid and released bleach catalyst directly on to the fabric.
A method of directly bleaching a fabric, by employing the dispensing device of claim 1 to dispense the fluid and released bleach catalyst directly on to the fabric.