The present invention relates to a dye scavenging substrate and a method for its manufacture. It is well known that a typical mix of materials being laundered will have somewhat different colours, even if sorted into the so-called "white" and "coloured" batches. Although fading of dyes is more prevalent from new, unlaundered, or heretofore infrequently laundered goods, even articles with considerable fastness to washing, or having a long history of numerous previous launderings, may continue to bleed small amounts of dyestuff or colourant into the bath or wash water. The well known, but aggravating and undesirable result of such fading is that at least part of the extraneous, free flowing colorant or dyestuff which has bled from its original article may then be absorbed, adsorbed, reacted with, or otherwise physically deposited on or associated with other articles in the same bath or wash water, thus discolouring the latter items. Reference is made to International Patent Publication No. WO-A-97/48789, which discloses a method for the manufacture of a dye scavenging substrate, and which disclosure is incorporated herein by reference. The dye scavenging substrate disclosed in WO-A-97/48789 has proven to be successful at scavenging extraneous, free flowing colourant or dyestuff. WO-A-97/48789 discloses the following method for the manufacture of the dye scavenger substrate:

(a) providing a cellulosic substrate;

(b) passing the substrate through a bath containing an alkaline solution of an N-trisubstituted ammonium 2-hydroxy-3-halopropyl compound having the general formula (I):

R ³

X-CH ₂ -CHOH-CH ₂ -N-R ⁴ -Y ^"

+ \

R ⁵

(I) wherein R ³ , R ⁴ , R ⁵ are each independently methyl, ethyl, butyl or benzyl or an hydroxyl substituted derivative thereof, X is a halogen atom, and Y is chloride, bromide, sulfate or sulfonate; or a salt of epoxy propyl ammonium having the general formula (II): /

CH ₂ -CH-CH ₂ -N-R ⁷ -Y' ^"

\ / +\

O R ⁸ (II) wherein R ⁶ , R ⁷ , R ⁸ and Y' have the same meaning as R ³ , R ⁴ , R ⁵ and Y, respectively, as defined above;

(c) subjecting the substrate to a pressure of between 0.69-1 .37MPa (100-200 psi);

(d) heating the substrate to a temperature of approximately 350°C;

(e) wrapping the substrate in a water impermeable material and rotating the material at a

temperature of between 150°C and 100°C for a period of between 1 hour and 12 hours;

(f) removing the water impermeable material and passing the substrate through an acid bath;

(g) subjecting the substrate to a pressure of between 1 .03 - 1 .72Mpa (150-250 psi); and

(h) drying the substrate.

The resultant substrate will be hereinafter referred to as the "48789 substrate". It is an object of the present invention to improve or augment the properties of the 48789 substrate.

It can be desirable to print a motif on such dye scavenging substrates, for example in order to identify the dye scavenging substrate, or to distinguish the dye scavenging substrate from inferior or imitation products. To date, motifs have not been printed on such dye scavenging substrates, as it has not been known how such motifs may be applied successfully. Furthermore, there could be a concern that such a motif, being coloured, might discolour some of the other articles present in a wash in which the dye scavenging substrate bearing the motif is used.

Accordingly, it is a further object of the present invention to provide a dye scavenging substrate which bears a printed motif which is conveniently washed away during a wash cycle and does not discolour other articles in the wash.

It is still a further object of the present invention to provide a dye scavenging substrate which bears a printed motif which is conveniently washed away during a wash cycle and does not discolour other articles in the wash, and which dye scavenging substrate additionally has improved dye scavenging properties compared with the 48789 substrate and other conventional dye scavenging substrates.

According to an aspect of the present invention there is provided a dye scavenging substrate comprising an absorbent substrate comprising:

(A) a dye scavenging compound selected from the following compounds:

(i) N-trisubstituted ammonium-2-hydroxy-3-halopropyl compound having the general formula (I)

R ³

/

X-CH ₂ -CHOH-CH ₂ -N-R ⁴ -Y ^"

+ \

R ⁵ (I) wherein R ³ , R ⁴ , R ⁵ are each independently methyl, ethyl, butyl or benzyl or an hydroxyl substituted derivative thereof, X is a halogen atom, and Y is chloride, bromide, sulfate or sulfonate; and

(ii) a salt of epoxy propyl ammonium having the general formula (II),

R ⁶

/

CH ₂ -CH-CH ₂ -N-R ⁷ -Y' ^"

\ / +\

O R ⁸

(II) wherein R ⁶ , R ⁷ , R ⁸ and Y' have the same meaning as R ³ , R ⁴ , R ⁵ and Y, respectively, as defined above; or a combination thereof; and

(B) a dye transfer inhibitor.

As used herein, a "dye scavenging compound" is intended to mean a compound which generally inhibits any dyestuff or colourant present in wash water from being undesirably absorbed, adsorbed, reacted with, or otherwise physically deposited on or associated with articles in the wash water. The dye scavenging compound which is applied to, adsorbed by, or impregnated into the absorbent substrate is generally a compound which has a high affinity for dyes or colourants and is generally capable of complexing therewith, as will be explained hereinafter. Whilst the terms "dye scavenging compound" and "dye transfer inhibitor" are generally interchangeable in the art, as used herein, a "dye scavenging compound" is intended to mean a compound that is fixedly associated with the absorbent substrate, for example by means of its attachment to the substrate, whereas a "dye transfer inhibitor" is intended to mean a compound that is releasably associated with the absorbent substrate, for example by virtue of the dye transfer inhibitor being water soluble or substantially water soluble.

A particularly preferred dye scavenging compound used in the present invention is a compound of the formula (I) which is 3-chloro-2-hydroxypropyltrimethylammonium chloride. Another particularly preferred dye scavenging compound is a compound of the formula (II) which is

glycidyltrimethylammonium chloride, also known as (2,3-epoxypropyl) trimethylammonium chloride. The dye scavenging compound (I) and/or (II) is preferably present in an amount of from approximately 10g to 30g, more preferably from approximately 15g to 25g, especially approximately 20g per square metre of absorbent substrate. The dye transfer inhibitor preferably comprises a polymer, more preferably a copolymer, even more preferably a copolymer of vinylpyrrolidone and vinylimidazole, still more preferably a modified copolymer of vinylpyrrolidone and vinylimidazole. A particularly preferred dye transfer inhibitor is a copolymer of 1 -vinylimidazole and 1 -vinyl-2-pyrrolidone, modified, preserved with 0.02% 1 ,2- benzisothiazolin-3-one and 0.2% diazolidinyl urea. This compound is a liquid and is sold under the trade name Sokalan® HP 66 K and is available from BASF. Other suitable dye transfer inhibitors include, but are not limited to, Sokalan HP 56 (also a copolymer of vinylpyrrolidone and vinylimidazole) in granular or liquid form.

The dye transfer inhibitor is preferably present in an amount of from about 0.00005g to about 0.1 g (dry weight) per 0.03125 square metre (12.5cm x 25cm sheet) of absorbent substrate, preferably from about 0.0001 g to about 0.005g (dry weight) per 0.03125 square metre (12.5cm x 25cm sheet) of absorbent substrate, more preferably from about 0.0001 g to about 0.0005g (dry weight) per 0.03125 square metre (12.5cm x 25cm sheet) of absorbent substrate, most preferably about 0.0003g (dry weight) per 0.03125 square metre (12.5cm x 25cm sheet) of absorbent substrate - approximately 0.0242g per square metre of absorbent substrate. The dry weight is the weight of the dye transfer inhibitor after it has been dried on the substrate.

Preferably, the dye scavenging substrate further comprises a colouring agent. Thus, the absorbent substrate preferably further comprises a colouring agent.

The colouring agent preferably comprises a pigment. Suitable pigments include organic pigments and metal complexes. Pigments derived from cadmium, carbon, chromium, cobalt, copper, iron, lead, titanium, and zinc may be used. Copper phthalocyanine pigments are preferred. Thus, the colouring agent preferably comprises copper phthalocyanine. However, a skilled person will appreciate that other pigments may be used.

The colouring agent may be in the form of a pigment dispersion, preferably an aqueous pigment dispersion. As used herein, the term "dispersion" is intended to mean a two phase system where one phase comprises finely divided particles, and the other phase comprises a bulk substance through which the finely divided particles are distributed. The finely divided particles may be referred to as the dispersed or internal phase, and the bulk substance may be referred to as the continuous or external phase. Thus, when a pigment is in the form of finely divided particles and is distributed throughout a bulk substance, the two phase system may be referred to as a pigment dispersion. As used herein, the term "aqueous pigment dispersion" is intended to mean a pigment dispersion in which the bulk substance comprises an aqueous preparation.

An aqueous pigment dispersion suitable for use in the present invention may be prepared by grinding or milling a water-insoluble pigment or pigments, and subsequently mixing the ground or milled water-insoluble pigment or pigments with an aqueous preparation as bulk substance. The aqueous preparation may comprise, for example, water and a surfactant.

A preferred aqueous pigment dispersion comprises copper phthalocyanine, a water-insoluble pigment. A copper phthalocyanine aqueous pigment dispersion sold under the trade name

Magnaprint Eco Blue HB, is particularly preferred. Magnaprint Eco Blue HB is available from Magna Colours Limited, United Kingdom. Thus, the colouring agent preferably comprises an aqueous pigment dispersion comprising copper phthalocyanine. Alternatively or additionally, the colouring agent may comprise water soluble dyes, solvent soluble dyes, water insoluble dyes, solvent insoluble dyes and pigments.

The colouring agent, when present, is preferably present in an amount of from about 0.00005g to about 0.1 g (dry weight) per 0.03125 square metre (12.5cm x 25cm sheet) of absorbent substrate, preferably from about 0.00008g to about 0.005g (dry weight) per 0.03125 square metre (12.5cm x 25cm sheet) of absorbent substrate, more preferably from about 0.0001 g to about 0.0005g (dry weight) per 0.03125 square metre (12.5cm x 25cm sheet) of absorbent substrate, most preferably about 0.00014g (dry weight) per 0.03125 square metre (12.5cm x 25cm sheet) of absorbent substrate. The dry weight is the weight of the colouring agent after it has been dried on the substrate.

Thus, in one embodiment, the invention conveniently provides a 48789 dye scavenging substrate bearing both a dye transfer inhibitor and a colouring agent.

The colouring agent is preferably provided on the substrate in the form of a printed motif and/or a uniform colour over the entire sheet. The motif may be in the form of any desired shape or shapes, colour or colours, and may comprise patterns, letters, numbers or a combination thereof.

Optionally, the dye scavenging substrate further comprises one or more components selected from a surfactant, a polymer, an anti-foaming agent, a rheology modifier and a preservative. In one embodiment, the dye scavenging substrate comprises a combination of a surfactant and a polymer. The components are described and defined in more detail hereinafter.

The absorbent substrate may be formed from any suitable material. Examples of suitable materials include cellulosic materials such as wood pulp, paper, textile materials, naturally occurring materials and synthetic materials, and mixtures thereof. Textile materials include woven and non-woven materials, such as cotton, cotton mixes, knitted fabrics, braided rope or bail. The absorbent substrate may conveniently comprise cotton. A preferred substrate comprises a blend of viscose and wood pulp, the ratio of viscose to wood pulp preferably being approximately 90:10 to 10:90, more preferably 50:50.

According to another aspect of the present invention there is provided a method for the manufacture of a dye scavenging substrate according to the invention, comprising the steps of:

(A) providing an absorbent substrate comprising a dye scavenging compound selected from the following compounds:

(i) N-trisubstituted ammonium-2-hydroxy-3-halopropyl compound having the general formula (I)

R ³

/

X-CH ₂ -CHOH-CH ₂ -N-R ⁴ -Y ^"

+ \

R ⁵

(I) wherein R ³ , R ⁴ , R ⁵ are each independently methyl, ethyl, butyl or benzyl or an hydroxyl substituted derivative thereof, X is a halogen atom, and Y is chloride, bromide, sulfate or sulfonate; and

(ii) a salt of epoxy propyl ammonium having the general formula (II),

R ⁶

/

CH ₂ -CH-CH ₂ -N-R ⁷ -Y' ^"

\ / +\

O R ⁸

(II) wherein R ⁶ , R ⁷ , R ⁸ and Y' have the same meaning as R ³ , R ⁴ , R ⁵ and Y, respectively, as defined above; or a combination thereof; and

(B) applying to the absorbent substrate a dye transfer inhibitor.

Preferably, the dye transfer inhibitor is as defined above.

The dye transfer inhibitor may be applied by any suitable printing process, including but not limited to, flexographic, reverse gravure, lithographic, screen printing and gravure, preferably reverse gravure or flexographic. Reverse gravure and flexographic printing processes are preferable due to the printing speeds possible, and precision in terms of achieving the desired amount of active ingredients on the sheet. For example, it is desired to provide a certain preferred amount of dye transfer inhibitor on the sheet, and such methods have surprisingly been found to enable such preferred amounts to be deposited. If too little dye transfer inhibitor is used, the desired colour protection is not achieved, and if too much dye transfer inhibitor is used, the consumer is not provided with the desired visual indication of dye scavenging on the substrate itself.

Preferably, in step (B), the dye transfer inhibitor is applied to the substrate using a reverse gravure printing process.

Optionally, step (B) comprises drying the substrate after the dye transfer inhibitor has been applied to the substrate.

Optionally, step (B) comprises the following steps:

(B)(i) applying to the substrate an aqueous solution comprising a dye transfer inhibitor and a carrier; and

(B)(ii) drying the substrate.

Preferably, in step (B)(i), the aqueous solution comprising dye transfer inhibitor and carrier is applied to the substrate using a reverse gravure printing process. A skilled person will appreciate that a reverse gravure printing process generally involves the use of a first (lower) roller and a second (upper) roller, whereby the dye transfer inhibitor to be applied to the substrate is contained in a tray adjacent the first (lower) roller. In use, the substrate is put onto a printing machine (not shown) on a roll, which is unwound as it is fed into the printing line. In use, the substrate is passed between the first and second rollers, as shown schematically in Figure 1 . Thus, the process operates as follows. The dye transfer inhibitor is picked up from the tray by the first

(lower) roller. The dye transfer inhibitor is then transferred onto the substrate as the substrate passes between the first and second rollers. The reverse gravure printing process may include using one or more rollers having a diameter of from about 100mm to about 200mm, preferably from about 1 10mm to about 180mm, most preferably about 130mm. The one or more rollers may have a hardness value of from about 60 shore A to about 90 shore A, preferably from about 70 shore A to about 85 shore A, more preferably from about 75 shore A to about 80 shore A, most preferably about 75 shore A or about 80 shore A.

Alternatively, in step (B)(i), the dye transfer inhibitor may be applied to the substrate by immersing the absorbent substrate in the (liquid) dye transfer inhibitor; or by spraying the liquid dye transfer inhibitor on the absorbent substrate.

It will be appreciated that step (B) may be described as at least partially impregnating the substrate with the dye transfer inhibitor. As described above, the dye transfer inhibitor may be provided in an aqueous solution comprising dye transfer inhibitor and carrier. Suitable carriers include but are not limited to solids, gels or liquids. Liquid carriers are preferred, especially an aqueous solution. The carrier preferably comprises a surfactant and a polymer.

The surfactant preferably aids water-solubility, which may be achieved by the fact that it has a strong negative charge which temporarily blocks the cationic charge of the dye scavenging compound, allowing the dye transfer inhibitor to wash cleanly away from the substrate in the laundry wash. Any suitable surfactant may be used, including anionic surfactants. A preferred surfactant is a surfactant comprising about 20 - 25% w/w percent of aryl sulfonate or alkylaryl sulfonate. An especially preferred surfactant comprises 1 -10% acetic acid, 1 -10% 2,2'-oxybisethanol, 20-25% aryl sulphonate, and less than 1 % phenol, and is sold under the trade name Nylofixan HF. The polymer is used to hold the dye transfer inhibitor on the substrate until it is washed. Any suitable polymer may be used, including hydroxyethyl cellulose, polyvinyl alcohol, polyvinyl acetate, polyvinylpyrrolidone, xanthan gum, and acrylics (polymers derived from acrylic acid and acrylates). A preferred polymer is the water-soluble synthetic polymer polyvinyl alcohol (PVA), especially a water- soluble polyvinyl alcohol (PVA) solution, sold under the trade name Polytab TA463.

The carrier may comprise from about 5% to about 95%, preferably from about 10% to about 90%, more preferably about 15% by weight of surfactant, and from about 5% to about 95%, preferably from about 8% to about 30%, more preferably about 10% by weight of polymer, the percentages by weight being percentages by weight of the carrier. The balance of the carrier may comprise water, if desired.

Optionally, the carrier may further comprise one or more of water, an anti-foaming agent, a rheology modifier and a preservative. Further optionally, the carrier may still further comprise one or both of a mineral and a thickener.

The anti-foaming agent is used to stop foaming in production. Suitable anti-foaming agents include those of the siloxane or silicone type, or mineral or vegetable oils, as will be appreciated by a skilled person. A suitable mineral oil is twitchell oil. It will be appreciated that any other suitable anti-foaming agent may be used.

The rheology modifier is used to help printing of dye transfer inhibitor. A preferred rheology modifier is diethylene glycol. Any other suitable rheology modifier may be used, for example other polyols, without intending to limit the invention thereto. The preservative is used to preserve against microbial contamination. Any suitable preservative may be used. Suitable preservatives include thiazolinone preservatives, for example a blend of methyl and benzisothiazolinone. A preferred preservative is an aqueous solution comprising 1 -10% 2- methyl-2H-isothiazol-3-one and 1 -10% 1 ,2-benzisothiazolin-3-one, sold under the trade name Acticide MBS. The mineral preferably washes away from the substrate during a wash cycle, taking the dye transfer inhibitor with it. Any suitable mineral may be used, for example sodium aluminosilicate, an acid salt comprising sodium, aluminium, silicon and oxygen. It will be appreciated that other natural or synthetic minerals may be used, e.g. acid salts. A particularly preferred mineral is sodium

aluminosilicate sold under the trade name Alusil ET.

A thickener is used to stop the mineral (sodium aluminosilicate) settling during production. Any suitable thickener may be used, e.g. a modified starch, such as that sold under the trade name Solvitose. Any other suitable modified starch (which may be modified using any conventional process) may alternatively be used.

All of the above ingredients are available from Magna Colours Limited, Dodworth Business Park, Upper Cliffe Road, Dodworth, Barnsley S75 3SP United Kingdom.

The carrier may comprise:

- from about 30% to about 80%, preferably from about 40% to about 60%, more preferably from about 45% to about 58%; even more preferably from about 48% to about 55% of water, still more preferably about 54% or 55% or 56% of water, most preferably about 54.4% by weight of water;

from about 2% - 15%, preferably about 3% to about 10%, more preferably about 5% by weight of surfactant;

from about 0.01 % to about 5%, preferably from about 0.1 % to about 2%, more preferably about 0.2% by weight of anti-foaming agent;

from about 10% to about 50%, preferably from about 20% to about 40%, more preferably about 30% by weight of polymer;

- from about 5% to about 15%, preferably from about 7% to about 12%, more preferably about 10% by weight of rheology modifier;

from about 0.01 % to about 5%, preferably from about 0.2% to about 2%, more preferably about 0.4% by weight of preservative;

from about 0% to about 15%, preferably from about 2% to about 15%, morepreferably from about 3% to about 10%, even more preferably about 5% by weight of sodium aluminosilicate; and

from about 0% to about 5%, preferably from about 0.05% - 5%, more preferably from about 0.5% to about 3%, even more preferably about 1 % by weight of thickener;

the percentages by weight being percentages by weight of the carrier. In one embodiment, the carrier comprises water, a surfactant, an anti-foaming agent, a polymer, diethylene glycol and a preservative. In this embodiment, the carrier may comprise

(i) from about 30% to about 80%, preferably from about 40% to about 60%, more preferably from about 45% to about 58%; even more preferably from about 48% to about 55% of water, still more preferably about 54% or 55% or 56% of water, most preferably about 54.4% by weight of water;

(ii) from about 2% - 15%, preferably about 3% to about 10%, more preferably about 5% by weight of surfactant;

(iii) from about 0.01 % to about 5%, preferably from about 0.1 % to about 2%, more preferably about 0.2% by weight of anti-foaming agent;

(iv) from about 10% to about 50%, preferably from about 20% to about 40%, more preferably about 30% by weight of polymer;

(v) from about 5% to about 15%, preferably from about 7% to about 12%, more preferably about 10% by weight of rheology modifier;

(vi) from about 0.01 % to about 5%, preferably from about 0.2% to about 2%, more preferably about 0.4% by weight of preservative;

the percentages by weight being percentages by weight of the carrier.

The carrier may also include other ingredients not listed here.

The aqueous solution comprising the dye transfer inhibitor and the carrier may comprise from about 85% to about 98%, preferably from about 90% to about 95%, more preferably about 92%, most preferably about 92.2% by weight of carrier, and from about 2% to about 15%, preferably from about 5% to about 10%, more preferably about 8%, most preferably about 7.8% by weight of dye transfer inhibitor, the percentages by weight being percentages by weight of the aqueous solution.

Optionally, the method further comprises:

(C) applying to the absorbent substrate a colouring agent, wherein step (C) is performed after step (B).

Preferably, the colouring agent is as defined above.

As described above with respect to the dye transfer inhibitor, the colouring agent may be applied by any suitable printing process, including but not limited to, flexographic, reverse gravure, lithographic, screen printing and gravure, preferably reverse gravure or flexographic. Reverse gravure and flexographic printing processes are preferable due to the printing speeds possible, and precision in terms of achieving the desired amount of active ingredients on the sheet. For example, it is desired to provide a certain amount of colouring agent on the sheet, as a printed motif, and such methods have surprisingly been found to enable such preferred amounts to be deposited. Furthermore, such methods conveniently enable the desired motifs to be accurately positioned on the sheet. Preferably, in step (C), the colouring agent is applied to the substrate using a reverse gravure printing process. Details of the reverse gravure printing process are as described above with respect to the dye transfer inhibitor. Optionally, step (C) comprises drying the substrate after the colouring agent has been applied to the substrate.

Optionally, step (C) comprises the following steps:

(C)(i) applying to the substrate an aqueous solution comprising a colouring agent and a carrier; and

(C)(ii) drying the substrate.

Preferably, in step (C)(i), the aqueous solution comprising colouring agent and carrier is applied to the substrate using a reverse gravure printing process.

Alternatively, in step (C)(i), the colouring agent may be applied to the substrate by immersing the absorbent substrate in the (liquid) colouring agent; or by spraying the liquid colouring agent on the absorbent substrate. It will be appreciated that step (C) may be described as at least partially impregnating the substrate with the colouring agent.

It will be appreciated that there can be any number of 'stations' used to print the substrate in a continuous process (with driers between the stations). Preferably two stations will be used, one applying dye transfer inhibitor, the other applying colouring agent. This gives more control of the amount per sheet. After the printing and drying process the material is wound onto a roll. The amount of dye transfer inhibitor, and colouring agent, applied to the substrate is controlled by the percentage solids in the respective formulations, the viscosity of the formula, the volume picked up by the roller and the speed of the roller.

As described above, the colouring agent may be provided in an aqueous solution comprising colouring agent and carrier. Suitable carriers are described above, wherein references to the dye transfer inhibitor are also applicable to the colouring agent. Thus, the carrier may comprise one or more of a surfactant, a polymer, water, an anti-foaming agent, a rheology modifier, a preservative, a mineral (e.g. sodium aluminosilicate), and a thickener, as described above, and in the ranges as described above. The carrier preferably comprises at least a surfactant and a polymer. It will be appreciated that the surfactant preferably aids water-solubility of the colouring agent applied to the substrate. It will also be appreciated that the polymer is used to hold the colouring agent on the substrate until it is washed. It will still be further appreciated that the rheology modifier, when present, is used to help printing of the colouring agent onto the substrate. The aqueous solution comprising the colouring agent and the carrier may comprise from about 92% to about 99.9%, preferably from about 95% to about 99%, more preferably 98.5% of carrier, by weight of the aqueous solution, and from about 0.1 % to about 8%, preferably from about 1 % to about 5%, more preferably about 1 .5% of colouring agent, by weight of the aqueous solution.

Optionally, the absorbent substrate comprising a dye scavenging compound as defined in step (A) of the method may be obtained by

(A)(i) providing an aqueous solution containing a dye scavenging compound of the formula (II) and/or (III) as defined above, or a combination thereof; and

(A)(ii) at least partially impregnating the absorbent substrate with said aqueous solution, the steps (A)(i) and (A)(ii) being performed prior to step (B).

Preferably, the aqueous solution of step (A)(i) is an alkaline solution. Further preferably, the alkaline solution is at a temperature of from about 30°C to 50°C, most preferably approximately 45°C.

Preferably, step (A)(ii) includes one or more of the following steps, as described in WO-A-97/48789:

(i) subjecting the treated substrate to a pressure of from about 0.69 to 1 .37

MPa (100-200 psi), preferably about 1 .03 MPa (150 psi), and, preferably, the pressure is obtained by passing the substrate between a pair of hydraulically actuated rollers, further preferably, at a rate of from about 184mm s ^" to 167mm s most preferably about 175mm s ^" ; heating the substrate to a temperature of approximately 35°C, wherein, preferably, the heating is achieved by passing the substrate through a series of rollers having a temperature of approximately 100°C so that the substrate exiting the rollers is at a temperature of between 30°C and 40°C, preferably about 35°C;

(iii) wrapping the substrate in a water impermeable material and rotating the material at a temperature of from about 15°C to 100°C for a period of from about 1 to 12 hours, preferably approximately 100°C with a storage time of a minimum of 6 hours.

(iv) removing the water impermeable material and passing the substrate through an acid bath;

(v) subjecting the substrate to a pressure of from about 1 .03 to 1 .72 MPa

(150-250 psi); preferably approximately 1 .38 MPa (200 psi), and, preferably, the substrate is passed through the rollers at a rate of from about 92 mm s ^" to 75 mm s further preferably approximately 83 mm s ^{" 1} ; and (vi) drying the substrate, preferably by subjecting the substrate to a temperature of from about 95°C to 1 15°C, most preferably about 105°C. Optionally, therefore, step (A)(ii) may comprise the following steps:

(i) subjecting the substrate to a pressure of between 0.69-1 .37MPa (100-200 psi);

(ii) heating the substrate to a temperature of approximately 350°C;

(iii) wrapping the substrate in a water impermeable material and rotating the material at a

temperature of between 150°C and 100°C for a period of between 1 hour and 12 hours;

(iv) removing the water impermeable material and passing the substrate through an acid bath;

(v) subjecting the substrate to a pressure of between 1 .03 - 1 .72Mpa (150-250 psi); and

(vi) drying the substrate.

Step (A) may be advantageously be carried out using the apparatus described in WO-A-97/48789.

Thus, the dye scavenging substrate of the present invention may, for example, be prepared by providing a 48789 substrate and subjecting the 48789 substrate to step (B) described above, or to steps (B) and (C) described above. According to a further aspect of the invention, there is provided the use of a combination of a surfactant and a polymer as a releasing agent for the colouring agent. Thus, the combination of the surfactant and the polymer enables the colouring agent to be releasably associated with the absorbent substrate, such that, during a wash cycle, the presence of the surfactant and the polymer enables the colouring agent to wash cleanly away from the substrate, without leaving a mark or stain. The surfactant, polymer, colouring agent and absorbent substrate are all preferably as described and defined herein.

In one embodiment, wherein a first aqueous solution comprising dye transfer inhibitor and carrier has been applied to the substrate in step (B), and a second aqueous solution comprising colouring agent and carrier has been applied to the substrate in step (C), it will be appreciated that after the final drying step, some of the components of the carrier will remain on the substrate. As previously described, the dye transfer inhibitor is preferably present in an amount of approximately 0.00030g (dry weight) per 0.03125 square metre (12.5cm x 25cm sheet) of absorbent substrate; and the colouring agent (in the form of a printed motif) is preferably present in an amount of approximately 0.00014g (dry weight) per 0.03125 square metre (12.5cm x 25cm sheet) of absorbent substrate. Thus, in one embodiment, when a carrier comprising surfactant, polymer, water, anti-foaming agent, rheology modifier and preservative is used with both the dye transfer inhibitor and the colouring agent, the following components are preferably present on the final sheet: surfactant, polymer, anti- foaming agent, rheology modifier and preservative, as defined above. The surfactant is preferably present in an amount of approximately 0.00059g (dry weight) per 0.03125 square metre (12.5cm x 25cm sheet) of absorbent substrate; the polymer is preferably present in an amount of approximately 0.00174g (dry weight) per 0.03125 square metre (12.5cm x 25cm sheet) of absorbent substrate; the anti-foaming agent is preferably present in an amount of approximately 0.00004g (dry weight) per 0.03125 square metre (12.5cm x 25cm sheet) of absorbent substrate; the rheology modifier is preferably present in an amount of approximately 0.00175g (dry weight) per 0.03125 square metre (12.5cm x 25cm sheet) of absorbent substrate; and the preservative is preferably present in an amount of approximately 0.00007g (dry weight) per 0.03125 square metre (12.5cm x 25cm sheet) of absorbent substrate. The weight of 0.03125 square metre (12.5cm x 25cm) of absorbent substrate is approximately 2.5g when dried. In contrast with the dye transfer inhibitor which is cationic in character and is releasably associated with the absorbent substrate due to its solubility in water, the dye scavenging compound (I) and/or (II), also cationic in nature, is fixedly associated with the absorbent substrate (as described for example in WO-A-97/48789). During the wash, both the dye transfer inhibitor and the dye scavenging compound (I) and/or (II) form complexes with the dyestuffs and colourants which have bled from the articles in the wash liquor, which tend to be anionic in nature. The dye transfer inhibitor conveniently forms complexes which are then washed away during the wash cycle. In contrast, the dye scavenging compound(s) (I) and/or (II) is not leached from the substrate during the wash. Thus, the complexes formed between the dye scavenging compound(s) and the dyes/colourants give the substrate a coloured appearance due to the presence of the dye complexed thereto. Accordingly, the dye transfer inhibitor advantageously improves the performance of the substrate, resulting in the articles in the wash becoming cleaner and staying brighter for longer, compared with the 48789 substrate alone, while the dye scavenging compound(s) (I) and/or (II) advantageously provides the proof on the substrate to the consumer that the substrate has worked effectively. The substrate and the method are versatile and may be adapted according to a particular need. For example, in one embodiment, the 48789 substrate may be printed with the dye transfer inhibitor only. In another embodiment, the 48789 substrate may be printed with an aqueous solution (comprising dye transfer inhibitor and carrier). In both cases, the dye transfer inhibitor (and carrier, when present), result in the articles in the wash becoming cleaner and brighter than when using the 48789 substrate alone. In another embodiment, the substrate may be printed with a first aqueous solution (comprising dye transfer inhibitor and carrier) followed by printing with a second aqueous solution (comprising colouring agent and carrier). The substrate may be printed on one side or both sides, with varying colours and patterns if desired, in order to produce the desired motif(s). When the colouring agent in present on the substrate in the form of a printed motif, the colouring agent and carrier will conveniently be released from the substrate during a wash cycle, with the carrier assisting the colouring agent to wash cleanly away from the substrate, so that it does not leave a mark. Thus, the carrier conveniently acts as a "releasing agent" for the colouring agent. In particular, the components of the carrier which remain on the sheet after drying may act as a releasing agent, namely the surfactant, the polymer, the anti-foaming agent, the rheology modifier and the preservative, especially the surfactant and the polymer. During a wash cycle, the presence of at least the surfactant and the polymer as a base layer for the colouring agent enables the colouring agent to wash cleanly away from the substrate, without leaving a mark or stain. The use of water-insoluble pigments such as copper phthalocyanine is also advantageous, since they wash off the substrate more effectively and are not attracted to the substrate. In summary, therefore, the invention conveniently provides a product that mops up dyes onto the substrate (by means of the dye scavenging compound(s)), and mops up dyes to be washed away (by means of the dye transfer inhibitor). Additionally, the product may conveniently be provided with a motif that washes cleanly away from the substrate in the wash, without leaving a mark or discolouring any other articles present in the wash. The effect is advantageously three-fold: the consumer can see that a change has taken place, by means of the motif disappearing from the substrate, the consumer can see that the extraneous dyes have been mopped up, by virtue of the colour change on the substrate, and the articles of clothes in the wash are made cleaner and brighter. DESCRIPTION OF FIGURES

Figure 1 is a schematic illustration of the arrangement of rollers during the reverse gravure printing process; Figure 2 shows the results of the colour transfer test using Direct Red 83.1 ; Figure 3 shows the results of the colour transfer test using Direct Orange 39; Figure 4 shows the results of the dye transfer test, using yellow cotton;

Figure 5 shows the results of the dye transfer test, using white cotton; Figure 6 shows the visual results of the dye transfer test, using yellow and white cotton; Figure 7 shows the results of the dye pick-up test;

Figure 8 shows the visual results of the dye pick-up test;

Figure 9 shows the results of the blue build-up test on yellow cotton;

Figure 10 shows the results of the blue build-up test on white cotton; Figure 1 1 is a photo of the substrates used in the tests; and Figure 12 shows the visual results of the blue build-up test on yellow cotton and white cotton. The following examples serve to illustrate the invention, but it will be appreciated that the invention is not limited to the examples described herein.

EXAMPLE 1

A dye scavenging substrate according to the invention may be prepared as follows.

A 48789 substrate is prepared as described in WO 97/48789, following which a dye transfer inhibitor, namely Sokalan® HP 66 K (liquid, copolymer of 1 -vinylimidazole and 1 -vinyl-2-pyrrolidone, modified, preserved with 0.02% 1 ,2-benzisothiazolin-3-one and 0.2% diazolidinyl urea, available from BASF) is applied using a reverse gravure printing process as follows.

The 48789 substrate is put onto the printing machine (not shown) on a roll, which is unwound as it is fed into the printing line. The liquid dye transfer inhibitor is contained in the tray at the bottom (see Figure 1), adjacent the first (lower) roller. The solution is picked up by the first (lower) roller from the tray and transferred onto the substrate as it passes between the first (lower) roller and second (upper) roller, in a reverse gravure printing process. The first and second rollers comprise rubber having a diameter of 130.7mm (circumference of 410.76), and a length of 1004mm. The first and second rollers have a hardness value of from 75 to 80 shore A. The substrate then passes through a drier (not shown). With reference to Figure 1 , once printed, the substrate is wound back onto a roll so it is ready for a standard rewind process and then sheeted into finished packs. The resultant amount of dye transfer inhibitor is 0.0003g (dry weight) per 12.5 x 25.0 cm sheet of substrate.

EXAMPLE 1 (A)

An alternative dye scavenging substrate according to the invention may be prepared as follows. An aqueous solution comprising dye transfer inhibitor and carrier is prepared as follows.

(A) Preparation of carrier A:

The following ingredients are added to a mixing vessel at room temperature in the order (A) - (F) and with constant stirring:

siloxane type ² comprises 1 -10% acetic acid; 1 -10% 2,2'-oxybisethanol; 20-25% aryl sulphonate; and less than 1 % phenol; ³ 10% actual PVA; Comprises 1 -10% 2-methyl-2H-isothiazol-3-one; 1 -10% 1 ,2-benzisothiazolin-3-one. The ingredients referred to above are all available from Magna Colours Limited, Dodworth Business Park, Upper Cliffe Road, Dodworth, Barnsley S75 3SP United Kingdom.

(B) Preparation of aqueous solution comprising dye transfer inhibitor and carrier A.

The following ingredients are added to a mixing vessel at room temperature in the following order and with constant stirring:

92.2% carrier A, prepared in part (A) above; and

7.8% Sokalan® HP 66 K (liquid, copolymer of 1 -vinylimidazole and 1 -vinyl-2-pyrrolidone, modified, preserved with 0.02% 1 ,2-benzisothiazolin-3-one and 0.2% diazolidinyl urea, available from BASF); by weight of the aqueous solution (therefore 92.2% by weight carrier A, and 7.8% by weight of dye transfer inhibitor, totalling 100% by weight). to form the aqueous solution of dye transfer inhibitor and carrier A.

(C) The 48789 substrate is prepared as described in WO 97/48789, following which the aqueous solution of dye transfer inhibitor and carrier A is applied using a reverse gravure printing process as described in Example 1 , wherein the aqueous solution of dye transfer inhibitor and carrier A is contained in the tray. The substrate is then dried. The resultant amount of dye transfer inhibitor on the final product is 0.0003g (dry weight) per 12.5 x 25cm sheet of substrate.

EXAMPLE KB)

The carrier A may be replaced by carrier B, as follows. (A) Preparation of carrier B:

The following ingredients are added to a mixing vessel at room temperature in the order (A) and with constant stirring:

siloxane type; ² contains 20-25% aryl sulphonate; ³ 10% actual PVA; ⁴ comprises sodium

aluminosilicate; ⁵ modified starch; ⁶ contains 2-methyl-2H-isothiazol-3-one 2.5%, 1 ,2-benzisothiazol- 3(2H)-one 2.5%. The ingredients referred to above are all available from Magna Colours Limited, Dodworth Business Park, Upper Cliffe Road, Dodworth, Barnsley S75 3SP United Kingdom.

The procedural steps of steps (B) and (C) of Example 1 (A) are then carried out using carrier B to produce a variation of the dye scavenging substrate of Example 1 (A). The resultant amount of dye transfer inhibitor on the final product is 0.0003g (dry weight) per 12.5 x 25 cm sheet of substrate.

EXAMPLE 1 (C)

A further alternative dye scavenging substrate according to the invention may be prepared by carrying out the procedural steps of Example 1 , 1 (A) or 1 (B), followed by the subsequent application of an aqueous solution comprising colouring agent and carrier.

The general method involves preparing an aqueous solution of colouring agent and carrier by mixing 98.50% by weight of the chosen carrier A or B (from Examples 1 (A) or 1 (B) respectively), with 1 .50% by weight of the colouring agent, pigment Magnaprint Eco Blue HB (copper phthalocyanine), wherein the percentages by weight are percentages by weight of the aqueous solution. In this example, carrier A is used, such that an aqueous solution of colouring agent and carrier A is prepared by mixing 98.50% by weight of carrier A, by weight of the aqueous solution, with 1 .50% by weight of the pigment Magnaprint Eco Blue HB (copper phthalocyanine) - (therefore 98.50% by weight carrier A, and 1 .50% by weight of colouring agent, totalling 100% by weight, based on the weight percent of the aqueous solution).

The general method involves applying the aqueous solution of colouring agent and carrier A using a reverse gravure printing process as described in Example 1 , either directly to a 48789 substrate containing the dye transfer inhibitor alone (Example 1) or to a 48789 substrate which has already been coated with an aqueous solution of the dye transfer inhibitor as described in Example 1 (A) or Example 1 (B). It will be appreciated by a skilled person that the specifications of the rollers used in the reverse gravure printing process conveniently enables any desired effect(s) to be achieved. In this example, the aqueous solution of colouring agent and carrier A is applied to a 48789 substrate which has already been coated with an aqueous solution of the dye transfer inhibitor and carrier A. The substrate is then dried. The resultant amount of colouring agent on the final product is 0.00014g per 12.5 x 25 cm sheet of substrate, as shown below:

siloxane type comprises 1 -10% acetic acid; 1 -10% 2,2'-oxybisethanol; 20-25% aryl sulphonate; and less than 1 % phenol; ³ 10% actual PVA; Comprises 1 -10% 2-methyl-2H-isothiazol-3-one; 1 -10% 1 ,2-benzisothiazolin-3-one. The ingredients referred to above are all available from Magna Colours Limited, Dodworth Business Park, Upper Cliffe Road, Dodworth, Barnsley S75 3SP United Kingdom. 4liquid, copolymer of 1 -vinylimidazole and 1 -vinyl-2-pyrrolidone, modified, preserved with 0.02% 1 ,2- benzisothiazolin-3-one and 0.2% diazolidinyl urea, available from BASF. The following comparative tests were performed in order to show the improved results obtained using the scavenging substrate of Example 1 (48789 substrate and dye transfer inhibitor only - see Examples 2, 3 and 4 below) and the scavenging substrate of Example 1 (C) (48789 substrate and dye transfer inhibitor, applied using the aqueous solution of dye transfer inhibitor and carrier A, and colouring agent, applied using the aqueous solution of colouring agent and carrier A - see Example 5 below).

EXAMPLE 2: COLOUR TRANSFER TEST

I - COLOUR TRANSFER TEST PROTOCOL

The test is carried out using a domestic MIELE Novotronic W526 washing machine. The dyes used for the tests are Direct Red 83.1 and Direct Orange 39.

The dye solutions are prepared so as to obtain an accurate concentration of 0.100 g/L for each dye.

Place in the washing machine:

three substrates according to the invention (prepared as described in Example 1), or three 48789 substrates, or none for the reference, at the bottom of the drum.

600x150mm white cotton swatch.

Introduce into the drawer of the washing machine:

60g ECE-2 washing powder.

- 60g (± 0.01 g) Direct Red 83.1 solution at 0.10 g/L

or 30g (± 0.01 g) of Direct Orange 39 solution at 0.10 g/L.

The container used for the dye solution is rinsed carefully with water. The rinsing solutions are used to remove both powder and dye solution from the drawer and its compartment. This is repeated several times until there are no traces of powder or dye left in the compartment. Keep the amount of rinsing solution constant for all the tests. This step is carried out as some dye tends to remain in or under the drawer after the wash. Check the absence of residual dye. For example, when carried out internally, the small beaker used for the dye is rinsed 5 times for each wash. Run a 60°C Short Cotton cycle.

Once the cycle is complete, remove the sheets and fabric from the drum and allow to dry naturally away from direct sunlight. Each product is tested with the 2 different dyes and each test repeated. The colorimetric difference ΔΕ is measured after each wash on the cotton swatches, taking the samples before wash as references.

II - PERFORMANCE EVALUATION A colorimetric measurement of the cotton before and after each wash is carried out using a Lovibond RT100 Reflectance Tintometer (spectrocolorimeter) - 10 measurements averaged per cotton swatch, cotton folded in 4 for the measurements.

The colour difference ΔΕ is reported for each product and different dyes.

III - RESULTS

The results obtained using Direct Red 83.1 were as follows, and as shown in Figure 2.

The results obtained using Direct Orange 39 were as follows, and as shown in Figure 3.

The colour transfer test illustrates the superior performance of the substrate of the invention, compared with the 48789 substrate and using no substrate, using commonly found dyes. These direct dyes are recommended in the industry for colour fast tests which can cause colour runs in domestic washing machines. The results show that the substrate of the invention performs the best with lower transfer of dye. EXAMPLE 3: DYE TRANSFER TEST

I - DYE TRANSFER TEST PROTOCOL

The test is carried out using a domestic MIELE Novotronic W526 washing machine.

The dye used for the tests is Direct Red 83.1 .

A dye solution is prepared so as to obtain an accurate concentration of 0.10 g/L.

Place in the drum of the washing machine: 1 anti-dye transfer sheet (substrate according to the invention (Example 1 )), or 48789 substrate, or no sheet for the reference.

600x150mm white cotton fabric.

600x150mm fast yellow cotton fabric.

Introduce into the drawer of the washing machine:

60g ECE-2 washing powder.

10g (± 0.01 g) of dye solution at 0.10 g/L. The container used for the dye solution is rinsed carefully with water. The rinsing solutions are used to remove both powder and dye solution from the drawer and its compartment. This is repeated several times until there are no traces of powder or dye left in the compartment. Try to keep the amount of rinsing solution constant for all the tests. This step is carried out as some dye tempts to remain in or under the drawer after the wash. Check the absence of residual dye.

For example, when carried out internally, the small beaker used for the dye is rinsed 5 times for each wash.

Select the short program option and run a 40°C cotton cycle. Once the cycle complete, remove the sheet and fabrics from the drum and allow to dry naturally away from direct sunlight.

5 washes are carried out successively with the same protocol, using new sheets for every wash. The colorimetric difference ΔΕ is measured after each wash on the cotton swatches, taking the samples before wash as the references.

The washing machine is rinsed (16min) in-between each wash to make sure there are no residues left. II - PERFORMANCE EVALUATION

A colorimetric measurement of the cotton before and after each wash is carried out using a Lovibond RT100 Reflectance Tintometer (spectrocolorimeter) - 10 measurements averaged per swatch, cotton folded in 4 for the measurements.

The colour difference ΔΕ is reported and plotted vs. the number of washes.

Ill - RESULTS

The results obtained were as follows, and as shown in Figures 4, 5 and 6. The Dye Transfer Test shows the substrate of the invention keeps the test materials brighter for longer, compared with the 48789 substrate or no substrate.

EXAMPLE 4: DYE PICK-UP TEST I - DYE PICK-UP TEST PROTOCOL

A 0.100g/L solution of Direct Red F3B 150% Dye is made up accurately in the lab and used for the following analysis. 1 . A 750ml aliquot of the Dye solution is heated in a beaker to 65°C.

2. A sample sheet of the substrate of the invention (Example 1) (125mm x 125mm) is placed on a device made internally for the purpose of keeping the sample sheet open during the test.

3. When the dye solution reaches a temperature of 65°C, it is transferred to a Stuart Bibbly SB161 -3 magnetic stirrer.

4. A magnet is placed into the beaker of dye and the stirrer switched on (stirring speed 5).

5. A stop watch is set at 3min and started when the sample sheet is placed into the solution of dye.

6. A 15ml aliquot of the dye solution is removed after one minute has elapsed and every consecutive minute after that; i.e. samples to be taken at time T1 = 1 min, T2 = 2min & T3 = 3min. These samples are labelled accordingly and put aside.

7. The samples are filtered prior to analysis using Millex®-AP 2.0μηι filters. 8. The UV-visible absorbance of the three samples is measured using a Hach DR/2500 Spectrophotometer to determine the residual dye content of the solution. The results are recorded.

The Hach Spectrophotometer was previously calibrated using known concentrations of Direct Red F3B 150% Dye solutions.

Each test is repeated 3 times.

II - PERFORMANCE EVALUATION

The Dye Pick-Up represents the amount of dye in mg absorbed by a full sheet of substrate according to the invention (250x125mm) at T1 , T2 and T3.

The correspondence is made between the absorbance (A) and the Dye Pick-Up value (DPU) using the following equation:

DPU (mg) = 150 - (A x 1500)

The absorbance measured ranges from 0.000 to 0.100.

As a result, the DPU will be Omg if no dye has been absorbed by the sheet and 150mg if all the dye has been absorbed by the sheet and the solution clear after the test.

The Dye Pick-Ups at T1 , T2 and T3 are reported and plotted for each sample.

Ill - RESULTS

The results obtained were as follows, and as shown in Figures 7 and 8.

Measured on a substrate

according to Example 1

The Dye Pick up Test shows the performance of the substrate of the invention in picking up colour such that the proof of dye pick-up is evident on the substrate. EXAMPLE 5: BLUE BUILD-UP TEST I - BLUE BUILD-UP TEST PROTOCOL

The test is carried out using a domestic MIELE Novotronic W526 washing machine. Place in the drum of the washing machine:

1 anti-dye transfer sheet (substrate as prepared in Example 1 (A) using dye transfer inhibitor and carrier A, followed by blue print at 1 .5% colouring agent and carrier A, (i.e. substrate of the invention as prepared in Example 1 (C)), or no sheet for the reference.

3kg white cotton fabric (Full load).

- 600x150mm fast yellow cotton fabric.

Introduce into the drawer of the washing machine:

60g ECE-2 washing powder. Select the short program option and run a 40°C cotton cycle.

Once the cycle complete, remove the sheet and fabrics from the drum and allow to dry naturally away from direct sunlight. 10 washes are carried out successively with the same protocol, using new sheets for every wash. The colorimetric difference ΔΕ is measured after each wash on the cotton swatches, taking the samples before wash as the references.

The washing machine is rinsed (16min) in-between each wash to make sure there are no residues left.

II - PERFORMANCE EVALUATION Colorimetric measurements of the yellow and white cottons before and after each wash are carried out using a Lovibond RT100 Reflectance Tintometer (spectrocolorimeter) - 10 measurements averaged per swatch, cotton folded in 4 for the measurements.

The colour difference ΔΕ is reported and plotted vs. the number of washes. III - RESULTS

The results obtained were as follows, and as shown in Figures 9, 10 and 12.

The blue build-up test shows that there is no transfer of the blue colouring agent onto white cotton and yellow cotton after 10 washes, clearly showing that the colouring agent printed on the substrate will not transfer onto other garments in a wash.

Figure 1 1 shows the 48789 substrate and the substrate according to Example 1 (C), which clearly shows the blue colour of the Example 1 (C) substrate (which has been printed on one side) compared with the 48789 substrate.

The examples described herein demonstrate that addition of a water-soluble dye transfer inhibitor, and optionally a colouring agent, to the 48789 substrate provides an improved substrate which is suitable for use in commercial and domestic laundry environments. The colouring agent on the substrate of the invention conveniently washed off and liberated the dye transfer inhibitor immediately on contact with wash water. The pigment did not stain the substrate. Furthermore, the colouring agent was not attracted back onto the substrate or other garments during the wash. The colouring agent did not inhibit the properties of the dye transfer inhibitor or the dye scavenging compound. In summary, as described above, from the results it is clear that the consumer can see that a change has taken place, by means of the motif disappearing from the substrate, the consumer can see that the extraneous dyes have been mopped up, by virtue of the colour change on the substrate, and the articles of clothes in the wash are made cleaner and brighter.