EP2142632A1

EP2142632A1 - Laundry treatment compositions with lamellar visual cues

Info

Publication number: EP2142632A1
Application number: EP08837128A
Authority: EP
Inventors: Janette Cutrona; Rudolf Govert Driel Van; Kees Bert Geerse; Edwin Leo Mario Lempers
Original assignee: Unilever PLC; Unilever NV
Current assignee: Unilever PLC; Unilever NV
Priority date: 2007-10-12
Filing date: 2008-09-25
Publication date: 2010-01-13
Anticipated expiration: 2028-09-25
Also published as: DE602008003428D1; MY145126A; AU2008309814B2; MX2009012389A; WO2009047124A1; CA2686494A1; CA2686494C; CL2008003016A1; AR068856A1; BRPI0811568A2; EP2142632B1; ATE487787T1; CN101755040A; PL2142632T3; CN101755040B; AU2008309814A1

Abstract

A laundry treatment composition comprising a laundry treatment base and from 0.01 to 10 wt% of contrastingly coloured concave lamellar film particles which have a planar surface and a planar periphery and wherein: a) the periphery is shaped so that at least one straight line drawn through the planar surface intersects the periphery at more than two places; b) the concave lamellar film particles may be tiled; c) the concave lamellar film particles contrast in colour with the laundry treatment base whereby the concave lamellar film particles function as visual cues.

Description

LAUNDRY TREATMENT COMPOSITIONS WITH LAMELLAR VISUAL CUES

This invention relates to laundry treatment compositions with lamellar visual cues cut from a film.

BACKGROUND

Laundry treatment compositions include fabric cleaning and other fabric care compositions, such as fabric softeners, specialist stain removal products etc. The compositions may take the form of solid compositions including detergent powders, solid detergent forms like tablets and bars, or liquid compositions.

It is known to include shaped lamellae in laundry treatment compositions .

GB2358403A suggests the use of shaped lamellae as visual cues in detergent powder compositions. The film is a coloured water-soluble plastics material. The lamellae are of significantly larger average particle size in at least one dimension than the average particle size of the contrasting powder particles. The examples in this patent application use 5 mm diameter circular or star shaped lamellae. In addition to the circles and stars used in the examples, GB2358403A discloses squares and triangles. Also disclosed are: mixtures of triangles, squares, pentagons and hexagons; mixtures of numerals, mixtures of letters of the alphabet; and mixtures of sun, moon and stars.

Cutting out circles, or star shapes, from a film leaves a high percentage of waste film material, which should be recycled. Such recycling is costly and inefficient. In addition, if sensitive ingredients are included in the film, there may be further constraints on recycling due to limitations on the heat or other treatment to which the film can be subjected without damaging the sensitive ingredient.

WO2006/079416 discloses an alternative shape for the lamellae serving as visual cues. Examples in this application use visual cues made from gum Arabic lamellae. The gum Arabic cues are irregularly shaped and are produced by fragmenting a large film to form random shapes with sharp angles, generally having a triangular or "spiky" appearance. Because the shapes are randomly sized, it is necessary to sieve them to get a suitable fraction for use. It is suggested that they could be chosen to pass a 1400 μm sieve, but not a 500 μm sieve. Up to 30% of the visual cues produced would need to be recycled, or wasted, if this method of production were used. Furthermore, we have found that consumers do not appreciate randomly shaped visual cues as much as regularly shaped ones.

WO2007/022229 discloses inclusion of small shapes of film, which may be visible, into a solid cleanser base, such as a soap bar. In addition to provision of visual contrast, the square film inclusions are taught to affect other sensory factors, such as feel of the product. EP 1319706 discloses a liquid detergent composition with a solid polymer film immersed in it. The concave lamellae are preferably regular in shape. In addition to the shapes already disclosed in GB2358403A, teddy bear shaped visual cues are also disclosed.

Both simple and complex tiled designs are generally known. In this specification tiled or tessellated is used in the sense that a surface, especially a plane surface, can be tiled by the shape or shapes. M. C. Escher created many complex tiled or tessellated designs comprising repeating patterns of shapes of animals, plants and things, such as geckos, birds, fish and boats.

Throughout this specification "tiled" means that a shape or shapes are shaped to be fitted together like a jigsaw, to form a continuous tiled planar surface with no gaps or overlaps, except for optional gaps at the edges of the planar surface. "Tilable" means that the shapes can be tiled.

Square, rectangular and hexagonal shapes can be tiled. It is possible to cut up a film to make simple visual cues with these shapes. There is generally little waste film from the cutting up process because the shapes can be created by slitting the film in continuous straight lines. However, we have found that such simple shapes may suffer from segregation problems in a powder composition and, more critically, do not function sufficiently well as visual cues. There thus remains a problem relating to the manufacture and use of low-waste shaped lamellae as effective visual cues in laundry treatment compositions, especially laundry detergents and most especially powdered laundry detergents.

It is a problem to make effective lamellar visual cue shapes by cutting them from a film in a manner that reduces or eliminates waste during production.

Another, related, problem is the cost effective manufacture of lamellar visual cues that impart additional functionality to laundry treatment compositions.

Another, related, problem for incorporation of lamellar visual cues in powders is to manufacture visual cues having a shape and size that enables them to be non-segregating and dispersed relatively uniformly throughout the powder.

SUMMARY OF THE INVENTION

According to the present invention, there is provided a laundry treatment composition comprising a laundry treatment base and from 0.01 to 10 wt% of contrastingly coloured concave lamellar film particles which have a substantially planar surface and a substantially planar periphery wherein: a) the periphery is shaped so that at least one straight line drawn through the substantially planar surface intersects the periphery at more than two places; b) the concave lamellar film particles can be tiled; c) the concave lamellar film particles contrast in colour with the laundry treatment base whereby the concave lamellar film particles function as visual cues.

DETAILED DESCRIPTION OF THE INVENTION

DEFINITIONS

Visual Cue

Means a consumer perceivable point of differentiation in a detergent composition. This could be a feature of the bulk composition: e.g. colour, viscosity, size of granules, or it could be achieved by having visually distinct particles included in the composition, in a minor amount.

Visual Cue Particle

Means a coloured speckle, film particle or other solid visually contrasting particle added to a detergent composition in a minor amount to function as a visual cue.

Lamellar Visual Cue (or Lamellae)

Means visual cue particles in the form of planar film material made into shapes. The shapes may be cut from a sheet of film or may be cast directly. Such lamellae are also called "film particles". Flower-Like or Flower Shaped

Means planar film shapes (or lamellae) that have the outline of the shape of a flower with petals. Especially a stereotypical flower having a central generally circular area with a number, preferably six, of rotationally symmetrically dispersed "petals" radiating therefrom.

The shape of the lamellae (lamellar film particles)

The concave lamellar film particles (concave lamellae) function as visual cues. To fulfil this function effectively we have found that they must have at least one visible indentation along their perimeter. This can be expressed mathematically as that for each design of concave lamellae it must be possible to draw a straight line that passes through the periphery of the film particle in more than two places. Convex shaped film particles; like squares, hexagons, and rectangles can never satisfy this requirement. Another way to express the required shape mathematically is that each lamellar film particle must either have at least one internal reflex angle, or it must have an indentation due to a curved part of its periphery.

Thus, a lamellar film particle having two straight parallel sides and two curved sides, one concave and the other convex of the same curvature, falls within the broadest scope of the invention, provided it is tileable and of a contrasting colour to the base composition. If there are discernable internal angles, the periphery of each of the lamellae preferably has no internal angles less than 100 degrees and must have at least one internal angle greater than 180 degrees (a reflex angle) . At least two such angles are preferred. Advantageously, in this case, all internal angles are less than 260 degrees, so that relatively fragile points are avoided.

Most preferred are shapes with twice as many internal angles in the range 100 to less than 180 degrees as in the range more than 180 to less than 260 degrees.

The shape of the visual cues is preferably selected from polygons modified to have at least two opposing sides provided with an outwardly extending generally convex distortion and a corresponding inwardly extending concave distortion such that the inward and outward distortions may be fitted together by tiling.

The shape of the visual cues is most preferably selected from polygons modified to have each side provided with an outwardly extending generally convex distortion and a corresponding inwardly extending concave distortion such that the inward and outward distortions may be fitted together by tiling.

Preferred polygons are hexagons.

A preferred shape for the concave lamellae is based on the normal construction of a, so called, Gosper island, as this enables a single and visually effective shape to be used. Koch snowflakes may also be employed if two different sized concave lamellae are desired. Gosper Islands and Koch snowflakes are well known fractal concepts and have been used previously as a basis for tessellated or tiled designs by mathematicians. A first iteration Gosper island is most preferred, as this has 18 straight sides. This shape is described in more detail below, with reference to the drawings .

It is even possible to utilise two completely different but complementary concave lamellae, as defined herein, to obtain the benefit of low waste attributable to the present invention .

To maximise the impact of a visual cue for perfume it is desirable for the shape of the lamellae to resemble something natural and normally associated with a smell; viz. a petal, a flower, etc. Advantageously, the shape of the concave lamellae and the smell of the composition are linked already in nature as this has been found to provoke the best possible response from the user. Most advantageously, the colour of the concave lamellae adds to the cueing and the colour, shape and smell should all be as close as possible to natural ones and related to the same smell, e.g. a floral smell. The size of the concave lamellae does not seem to be as important as its shape or colour. This freedom to use smaller than life sized representations of objects as visual cues enables the use of more cues for the same surface area. For instance using a 5 mm diameter visual cue with an approximate cross-sectional area of 13 mm² allows incorporation of the concave lamellar visual cues into a laundry treatment composition to deliver from 50 to 100 such cues per wash, preferably about 70 per wash.

Natural shapes that may also be used for concave lamellae that can be tiled are trees, leaves and animals. A particularly advantageous shape for use as a visual cue for perfume is a flower-like shape, especially one based on a hexagon suitably modified to keep its design tilable. Each side of the hexagon is preferably modified in an identical fashion. Thus, each side has both protruding and intruding distortions that are displaced reflections of one another, the previously opposite parallel faces of the hexagon being modified so that the new surfaces are also substantially parallel, but more complex, lines. For instance, the modified faces may be sinusoidal or they may be formed of three interconnected lines. Preferably, the new perimeter line intersects the original perimeter of the hexagon substantially at the midpoint of a side of the original unmodified hexagon.

For ease of manufacture, it is preferred that the majority of the sides of the concave lamellae are straight, most preferably they are all straight.

Advantageously all the concave lamellae have substantially the same shape. They may all have substantially the same size to minimise segregation issues.

The concave lamellae desirably have rotational symmetry. The preferred first iteration Gosper islands have this symmetry. The concave lamellae may all be the same colour, or they may comprise a mixture of different colours. The colour, or colours, of the concave lamellae may be selected to match the pack colour, or colours. Most preferred colours are lilac, pink, yellow, blue, red, purple, green, and orange. For dark coloured base laundry treatment compositions, e.g. blue, green it is possible to use a white contrasting concave lamellar cue. The whiteness may be imported by use of a white pigment.

Preferably, the shape of the concave lamellae is directly linked to an aspect of the base laundry treatment composition. Examples are that the shape is the outline shape of a flower and the composition has a perfume, especially a floral perfume. Ideally, the concave lamellae would also be the colour of a flower petal in this instance. A further example is that the concave lamellae are the outline shape of a bolt of lightening and the composition comprises a whitening, or bleaching, ingredient. In yet another embodiment the concave lamellae could be the outline shape of a plant and the composition contain a plant extract, like Aloe Vera.

When tiled the concave lamellae are desirably arranged in rows and columns and they are aligned in columns and offset in rows .

Film composition and properties

The concave lamellae (concave lamellar film particles) are manufactured from a film. A wide range of film compositions and properties may be used. Soluble film is preferred. The thickness of the film is important. Too thick or thin and it cannot be cut efficiently and at the required level of complexity without tears or distortions being created by the shear applied during cutting. The maximum thickness of the film is 0.4 mm, preferably 0.25 mm, most preferably 0.2 mm. The minimum thickness is 0.05mm, preferably 1 mm.

The tear strength and brittleness of the film at the thickness used should be tested to ensure that they are suitable. This is a simple matter and the values will vary depending on the exact process being used. Too soft a film will not cut easily whereas too brittle a film may shatter and make it difficult to achieve the desired shape at an economical rate of production. Such fragmentation also increases the amount of undesirable lower sized waste material that may need to be removed before adding the shapes to the laundry composition. For polymer films the properties may be controlled by plasticisers and fillers, as is known in the art. For films that additionally comprise a surfactant the water content of the film may also be adjusted to vary the properties.

The film may be coloured or opaque or it may be partially clear. In each case, it is possible to print onto the film either before or after it is cut, to provide a single colour, multiple colours or a pattern such as a representation of a natural object, like a leaf or flower.

Functional ingredients for treatment of laundry may be incorporated into the film before it is cut. Useful ingredients include TAED, Gerol, DTI-I, enzymes, fluorescer, shading dye and perfume. The most preferred ingredients for use in films are those that only need to be present at very low levels in the powder formulation, especially perfume, shading dye, bleach catalysts, fluorescer. Such materials may be instable in detergents due to interaction with moisture and other ingredients. The film also permits a greater range of soluble dyes to be used than was possible for speckles. It also gives the advantage that there is very little if any bleeding of dye into the bulk of the powder. Soluble dyes are generally preferred over pigments.

For incorporation of sensitive ingredients into the film, it is advantageous if the film contains polyvinyl alcohol (PVA) . The preferred grades of PVA are selected so that the film picks up water only at an RH well above that of the laundry treatment composition, e.g. detergent powder. Thereby it protects the ingredients from decomposition by water and soluble dyes from bleeding.

The use of tilable designs to cut the film into shaped visual cues reduces waste from the cutting process and thus minimises the amount of film that has to be wasted or recycled, which is important when sensitive or expensive additives are incorporated into the film.

Some film additives, such as fluorescer, may increase the effect of the visual cue. It is also possible to include a low level of dye to counter any yellowing. The functional ingredient is preferably incorporated into the film at a level to comprise an effective amount for treatment of laundry, based in the total amount of film in an average dose of lamellae to a wash.

As an even lighter weight alternative to film it is possible to fabricate meshes or open structures of polymer based material and to cut those into shapes in the same way as films. The same advantages of use of the tilable shapes apply. The expression "film" is intended to include such functionally equivalent laminar structures.

Preferred film compositions comprise soluble polymer and surfactant .

Optional further ingredients are: adjuncts to assist in the manufacture of the film, for instance release agents and water. Besides its effect of control of relative humidity of the film, water also assists in plasticising the film and regulates its solubility.

The polymer may be selected from water soluble film forming polymers, especially those used in formulation of detergent powders. Preferred polymers include polymers which dissolve and/disperse completely in water within 30 minutes with agitation at a temperature anywhere in the range of from 293 to 333K.

Preferred water soluble polymers are those capable of being cast into a film or solid mass, for example as described in Davidson and Sittig, Water-Soluble Resins, Van Nostrand Reinhold Company, New York (1968). Preferred water-soluble resins include polyvinyl alcohol, cellulose ethers, polyethylene oxide, starch, polyvinylpyrrolidone, polyacrylamide, polyvinyl methyl ether-maleic anhydride, polymaleic anhydride, styrene maleic anhydride, hydroxyethy1cellulose, hydroxypropylmethy1cellulose, polyethylene glycols, carboxymethylcellulose, polyacrylic acid salts, alginates, acrylamide copolymers, guar gum, casein, ethylene-maleic anhydride resin series, polyethyleneimine, ethyl hydroxyethylcellulose, ethyl methylcellulose, hydroxyethyl methylcellulose, sugars. Lower molecular weight water-soluble, polyvinyl alcohol film- forming resins are preferred.

Polyvinyl alcohols preferred for use therein have an average molecular weight anywhere between 1,000 and 1,000,000, preferably between 5,000 and 250,000, for example between 15,000 and 150,000. Hydrolysis, or alcoholysis, is defined as the percent completion of the reaction where acetate groups on the resin are substituted with hydroxyl, -OH, groups, A hydrolysis range of from 60-99% of polyvinyl alcohol film-forming resin is preferred, while a more preferred range of hydrolysis is from about 70-90% for water-soluble, polyvinyl alcohol film-forming resins. The most preferred range of hydrolysis is 80-89%. As used in this application, the term "polyvinyl alcohol" includes polyvinyl acetate compounds with levels of hydroloysis disclosed herein. Another suitable polymer is a polyvinyl alcohol film, made of a polyvinyl alcohol copolymer having a comonomer having a carboxylate function.

The preferred grade of PVA picks up water only at an RH well above that of granular detergent compositions. Thereby, it protects the other film ingredients from decomposition by water and soluble dyes from bleeding.

The concave lamellae may comprise 10 to 80% polymer or polymer mixture.

Although any suitable surfactant or surfactant system, may be used. The surfactant is preferably an anionic surfactant, especially if it is added to a granular composition comprising builder.

Suitable anionic surfactants include are well-known to those skilled in the art. Examples of high-foaming sulphonate or sulphate type surfactants include alkylbenzene sulphonates, particularly linear alkylbenzene sulphonates having an alkyl chain length of Cs-Ci₅; primary and secondary alkylsulphates, particularly Cs-Ci₅ primary alkyl sulphates; olefin sulphonates; alkyl xylene sulphonates; dialkyl sulphosuccinates; and fatty acid ester sulphonates. Sodium salts are generally preferred.

Further information is given in the open literature, for example, in "Surface-Active Agents and Detergents", Volumes I and II, by Schwartz, Perry and Berch. The preferred anionic surfactants are alkylbenzene sulphonates, more especially linear alkylbenzene sulphonate (LAS), which is preferably present in an amount of from 12 to 24 wt%, more preferably from 12 to 22 wt% and especially from 15 to 22 wt%.

Even more preferred are primary alcohol sulphates (PAS), particularly Cs-Cis, preferably C12-C15, primary alcohol sulphates. A particularly preferred surfactant is primary alcohol sulphate (PAS) with a carbon chain length of 12.

Visual cue Film particles containing up to 50 % PAS, may be used.

The film may additionally include a second surfactant. The second surfactant is preferably chosen from amphoteric surfactants, zwitterionic surfactants, nonionic surfactants and ethoxylated anionic surfactants.

Preferred amphoteric second surfactants are amine oxides. The most preferred amine oxide is coco dimethylamine oxide.

Preferred zwitterionic second surfactants are betaines, and especially amidobetaines, for example, coco amidopropyl betaine .

Preferred nonionic second surfactants include the primary and secondary alcohol ethoxylates, especially the C8-C20 aliphatic alcohols ethoxylated with an average of from 1 to 20 moles of ethylene oxide per mole of alcohol, and more especially the C10-C15 primary and secondary aliphatic alcohols ethoxylated with an average of from 1 to 10 moles of ethylene oxide per mole of alcohol.

Preferred ethoxylated anionic second surfactants, include alkyl ether sulphates (ethoxylated alcohol sulphates) .

Also suitable for use as second surfactants in the visual cues of the present invention are Cs-Cis alkyl monoethanolamides, for example, coco monoethanolamide .

The second surfactant system used in the film particle may additionally comprise minor amounts, e.g. less than 5% of the film, of cationic surfactant.

Surfactant may be included at a level of up to 90 wt%, preferably up to 75 wt%, most preferably up to 60 wt% in the film.

Non fabric-substantive colorants may be included in the film composition at a level of 0.001 to 0.5 wt%, preferably 0.10 to 0.20 wt%. Preferred film colorants selected from the group comprising: orange, yellow, pink, blue, red, green, purple and lilac.

Manufacture of concave lamellae

The tilable shapes used for the concave lamellae may be made by punching or embossed roller cutting processes and some reduction of waste versus the known star or circle shaped visual cues is possible using these processes. However, to - I i

our surprise we also found that the preferred tilable shapes can be made at small diameters and with very low waste production via rotary cutting processes.

By small diameter, we mean 2 to 10mm across, preferably having a mean diameter of about 5 mm. Shapes can be produced with straight sides, which look very similar to an even more complex curved shape. This gives 'real' shapes at an economically acceptable cost. As an example, a flower- like tilable design shown in Figure 6, with 18 intersecting straight sides, is sufficiently similar in shape to a real flower to be almost indistinguishable by the user of the laundry composition. Such a shape is therefore preferred over squares and even over hexagons, especially when the composition to which it is added also comprises perfume and most especially when the colour of the flower is selected from the natural flower imitating shades, for example: orange, yellow, pink, blue, red, green, purple and lilac.

For the design shown in Figure 6, some edge waste is inevitably generated during cutting, this may be fully or partially separated from the intended design shapes by sieving to give a waste percentage (by weight of the film) , for recycling, as low as 0.5 to 1 wt%. The amount of film in the laundry composition that is not in the desired concave lamellar form should be less than 10 wt%, preferably less than 5 wt%, and most preferably less than 2 wt% of the total amount of film in the composition. This cutting waste is predominantly concave lamellae that are misshapen and/or too small to be effective as visual cues. Advantageously the laundry composition has 0 to 1.5 wt% particles smaller than the target concave lamellar shapes and sizes, preferably as close to zero as economically feasible.

Incorporation of the concave lamellae into the laundry treatment base

For laundry bars, the visual cues are added towards the end of the manufacturing process to avoid damaging them. For laundry liquids, they may be suspended as described in EP 1319706. For laundry powder compositions, they must not unduly segregate during manufacture including mixing, handling, and transport.

The laundry treatment composition is advantageously provided in a coloured pack that has a predominant theme colour. Desirably the colour or colours of the concave lamellae match the pack colours; most preferably, they are a single colour and match the predominant theme colour of the pack.

The laundry treatment base is preferably a solid detergent composition; most preferably, it is a granular laundry detergent .

In such a granular composition, to improve the visibility of the visual cue it should have a cross sectional area much larger than the average of the base composition granules. However, this creates a potential problem during manufacturing and/or transport as particles of a different shape from the bulk tend to segregate, which leads to unacceptable dosing variability of the visual cues and undermines their effectiveness.

In order to keep the level of segregation within acceptable limits where the number of cues per wash will be sufficient, the concave lamellae should have density, thickness, diameter, and shape within defined boundaries. These have been determined experimentally and checked by means of trials .

There is evidence that the experienced level of segregation actually has a positive effect on performance due to a 'surprise' factor about the number of concave lamellae visible at any time.

Weight and density are the key parameters to keep segregation within acceptable limits. Weight is a function of thickness, diameter and shape.

To avoid undue segregation in a powder composition the weight of the visual cue should lie in the range 1 to 4 mg, preferably 1.5 to 3.5 mg. The density of the film should lie in the range 200 to 800 g/1, preferably 230 to 500 g/1, most preferably 250 to 400 g/1. In principle the higher the weight and the higher the density the less the segregation - up to a limit. However, this is uneconomical as the inclusion level in the powder will have to increase (the number of concave lamellae will stay constant for a given visual effect) . The density of the film may be controlled by varying the degree of aeration during film manufacture. Segregation experiment

Measurements were done with a standard colorimeter on a poured out powder bed. The measurement diameter was around 5 cm.

The white powder had the following colour (5 measurements) :

L a b average 96 .08 0. 14 2. 59 stdev 0. 07 0. 02 0. 10

The same powder with 0.15 wt% pink petal-shaped tilable concave lamellae visual cues had the following colour (10 measurements) :

L a B average 95 .75 0. 85 2. 66 stdev 0. 36 0. 44 0. 06

So inclusion of the tilable pink concave lamellae leads to an increase of a-value (with a large stdev) and to a higher stdev in L value. The increase in stdev is a result of the random number of tilable concave lamellae per measurement. This is corroboration of the "surprise" factor discussed above.

Efficacy as visual cue

a) In the laundry treatment composition Use of concave lamellae matched to the colour of the pack amplifies their effect as visual cues. Having the base laundry treatment composition add to the overall effect can also be very useful. For example having some green speckles in a base laundry detergent powder has been found to combine with petal coloured concave lamellae to emphasise a flower- like appearance, this reinforces the natural perfume used in the formulation and is further reinforced by the use of a similar predominant colour for the pack.

Choosing regularly shaped concave lamellae with concavities; particularly concavities close in scale, 1 to 2 mm curvature, to that of the convex surface of a typical laundry treatment composition granule is beneficial for appearance. Furthermore, concave lamellae that are reminiscent of a natural shape, especially if that shape can be linked also to the corresponding natural perfume, is especially desirable if the concave lamellae are to provide a visual cue for perfume.

b) In use, when the composition, including the concave lamellae, is added to water

The potential consumer preference for a flower shape over a hexagon was established by means of a controlled experiment using hand washing. The hand wash panellists were asked to describe the attributes of the wash experience and the resulting washing product and they evaluated the flower shaped visual cues above hexagon visual cues in terms of whiteness of the wash and freshness of the wash. The overall washing experience was also ranked as superior.

The invention will now be described, by way of example only, and with reference to the accompanying drawings of which.

Fig 1 is a pictorial representation of tiled concave lamellae, which are modified hexagons.

Fig 2 is a pictorial representation of tiled concave lamellae, which are modified hexagons with a second, more rounded, design.

Fig 3 is a pictorial representation of tiled concave lamellae of two different sizes and shapes.

Fig 4 is a pictorial representation of tiled concave lamellae based on three fused hexagons.

Fig 5 is a drawing showing how the first iteration Gosper Island design is generated.

Fig 6 is a pictorial representation of the cross-section of the Gosper Island design produced according to Fig 6

Fig 7 is a pictorial representation of tiled concave lamellae of the design shown in Fig 6.

Fig 8 is a pictorial representation of a concave lamellae design having an intrusion formed by a single convex curved side and single corresponding concave side. Figure 1 shows a complex tilable design of repeating identical shapes, 1, which each have six rotationally symmetrical "petals" that give each shape the impression of looking like a flower. Each "flower" can be considered to be a modified hexagon. The unmodified side of one of the hexagons 2 has been distorted to have a generally concave intrusion, 3, to the original hexagonal outline and a generally convex protrusion, 4. The convex and concave parts join together at the mid point of the original side. In this instance, the each part is rotationally identical to the other. If the concave part 3 is rotated 180 degrees about the midpoint intersection, it lies over the convex part 4. This means that the area of the shape is not changed from the original hexagon, but the visibility is improved by virtue of the increase in diameter and the overall appearance and functionality as a visual cue is enhanced by virtue of the flower-like appearance.

Figure 2 shows a modified form of the flower-like tilable shapes of figure 1. The concave lamellae have an overall diameter of 5 mm as indicated. They are arranged in columns and the rows are offset relative to one another. Relative to hexagon side 5, the intrusion and protrusion, 6, 7 are more rounded than the corresponding parts of Figure 1. The intrusion 6 does not have a sharply defined reflex angle at a junction, as is the case with figure 1. The indentation is curved and it forms the necessary indentation and reflex angle by the curvature.

Figure 3 shows a different type of tilable design where the concave lamellae 8 and 9 are of two different shapes and sizes. For each large particle, 8 there are two small particles, 9. The concave lamellae have at least one indentation and a corresponding internal reflex angle.

Figure 4 is a simple tilable design formed from the fusion of three hexagons. Concave lamellae 10 are identical in shape and size. Each concave lamellar particle has an internal reflex angle 11 of 240 degrees and two adjacent internal angles of 120 degrees. The concave lamellae may be separated by cutting to leave no waste formed from the area between lamellae and just a small amount of triangular shapes from the edges, depending on the number of rows and columns of concave lamellae that are cut from a single piece of film. This may be sieved and larger pieces used in the composition.

Figure 5 shows a modified hexagon design that is a first iteration of a shape known as a Gosper island. Here the original hexagon 11 has seven smaller hexagons imposed onto it such that six of the smaller hexagons have a portion 15 that protrudes beyond the original hexagon 11. Likewise, a corresponding intrusion 16 is formed and the protrusion and intrusion have the same areas and are rotationally symmetrical about the midpoint 14 of the original hexagon 11. Figure 6 shows in detail the modified shape formed when the concave lamellae 17 are cut out according to the first iteration Gosper island design. The concave lamellae has an internal reflex angle 18 and adjacent to each internal reflex angle 18 are two internal obtuse angles 19, the ratio of such obtuse angles 19 to reflex angles 18 is two to one. This gives a simple flower like design using only straight lines for the edges of the shape. Figure 7 shows how these concave lamellae shapes are arranged in columns 20, 21, 22 and how two sets of displaced rows are formed by alternate columns .

Figure 8 shows a simple concave lamellae design 25 that can be tiled. It has a curved indented area formed by side 26 and corners 27 and 28 are obtuse and acute respectively. The necessary reflex angle is provided by the curved side 26.

Example

A polymer film is manufactured having the following composition :

Polyvinyl Alcohol (polymer) 46.5%

Sodium Lauryl Sulphate (surfactant) 46.5% Colorant/dye (pink) 0.02%

Water and minors 6.98%

The film is made by dissolving the ingredients in water to form a homogeneous solution. This solution passes through an aeration unit, where air is mixed into the solution. The aerated liquid is then cast into a film and dried.

The film thickness is 0.18 - 0.19 mm and its relative density is about 0.3. It is cut into the flower-like tilable shapes according to figures 6 and 7. The maximum diameter of the shape is 5 mm and the cross-sectional area of one of the flat faces of the flower shape is approximately 16 mm². Two processes were used to cut the film into the required shapes: Rotary cutting and punching. The former generated some edge waste that was reduced by sieving. The latter produced a web of waste film that needed to be recycled. The amount of such film was, however, less than would have been generated by punching of non-tilable designs.

The cut concave lamellae were incorporated into a white carbonate STPP built LAS surfactant based detergent powder with a particle size of granule of less than lmm, in a manner similar to that used for other ingredients that are dosed at the end of the powder making process. The shapes were dosed, either manually or by a dosing unit, into mixing equipment where they were incorporated into the product. This mixing was either done mechanically, using a rotary mixing unit, or was done by blowing air into the powder. After mixing, the final powder is transported to the filling machines where the powder is conditioned in coloured bags or boxes of different sizes.

Claims

1. A laundry treatment composition comprising a laundry treatment base and from 0.01 to 10 wt% of contrastingly coloured concave lamellar film particles which have a planar surface and a planar periphery and wherein: a) the periphery is shaped so that at least one straight line drawn through the planar surface intersects the periphery at more than two places; b) the concave lamellar film particles can be tiled c) the concave lamellar film particles contrast in colour with the laundry treatment base whereby the concave lamellar film particles function as visual cues .

2. A laundry treatment composition according to claim 1 characterised in that each of the concave lamellar film particles has at least one concave indentation in its perimeter formed by two lines including an internal reflex angle .

3. A laundry treatment composition according to claim 1 characterised in that each of the concave lamellar film particles has at least one concave indentation in its perimeter formed by a concave curve.

4. A composition according to any preceding claim in which all the concave lamellar film particles have the same shape.

5. A composition according to any preceding claim, in which the laundry treatment base is a granular laundry detergent, the weight of each concave lamellar film particle lies in the range 1 to 4 mg and the density of the film lies in the range 200 to 80Oq/ I.

6. A composition according to any preceding claim in which all the concave lamellar film particles are the same size.

7. A composition according to any preceding claim in which the concave lamellar film particles have rotational symmetry.

8. A composition according to any preceding claim wherein the perimeters of the concave lamellar film particles are formed entirely from straight sides.

9. A composition according to any preceding claim in which the concave lamellar film particles are first iteration Gosper islands.

10. A composition according to any preceding claim in which the concave lamellar film particles are all the same colour.

11. A composition according to any preceding claim in which the composition is packed in a pack and the colour of the concave lamellar film particles matches the pack colour.

12. A composition according to any preceding claim in which the concave lamellar film particles are flower shaped and the composition is perfumed.

13. A composition according to any preceding claim in which when tiled the concave lamellar film particles are arranged in rows and columns and they are aligned in columns and offset in rows.

14. A composition according to any preceding claim in which the concave lamellar film particles further comprise an effective amount of a functional ingredient for treatment of laundry, based on the average dose of the lamellar film particles to a wash.