GB2349895A - Indicator product - Google Patents

Abstract

An indicator product is described. The product includes a substrate and a colour indicator component distributed on and/or in the substrate. A barrier composition is present on the substrate to substantially isolate colour indicator distributed on and/or in the said substrate from the surrounding environment.

Description

2349895 AN INDICATOR PRODUCT The invention relates to an indicator product

and, in particular, but not exclusively an indicator product to alert a user of a disposable product in sheet form that the product has performed its function and / or has exhausted its capacity for releasing an active material. The invention also relates to a process of using such a product.

In particular the invention is considered particularly suitable for a tumble dryer fabric conditioning sheet. Such sheets consist of a porous substrate, an impregnated softening compound and perform their function by being agitated with textiles, usually at elevated temperatures, such as to distribute the impregnated softening material. Such products are highly concentrated and occupy a smaller volume than a liquid conditioner and are widely used.

The fabric conditioner sheet suffers from the principle disadvantage that the consumer is unaware of the progress or completeness of its action and can only indirectly ascertain this by feeling the greasiness of the cloth and potentially infer its residual activity. This is particularly important as physical contact with the hot concentrated chemical impregnate is largely undesirable and the drying process is determined by the operator rather than being a set time period as in an automatic washing machine. The latter may lead to too short an application time, incomplete product action and be perceived as a product deficiency.

The use of wipes and tumble dryer sheets is well established. A wide range of substrate materials are also known (US 2228033, 1941, Martone, US3,301,746,1967, Sanford et al. US 3,414,459, 1968, Wells. US 3,499,316, 1970, Krause, US 3,775,231, 1973, Thomas. US 3,837,996, 1974, Braun et al., US 4,231,370, 1980, Mroz et al..) Various product forms for delivering active materials, typically softeners and anti-static agents in tumble dryers have been disclosed. For example US 3, 634, 947, US 3, 686, 025 and US 3, 442, 692 disclose a fatty alkyl cationic surfactant based product with various methods of application in a dryer.

US 3,936,538 discloses a waxy surfactant softening agent and a film forming polymer added in a tumble dryer. No disclosure of the film forming polymer as an encapsulant is or of the softening agent residing predominantly within a protective coating or of colour change is disclosed.

US 5, 834, 099 discloses a disposable sheet product with an indicator means. The indicator provides a differential change in greyness of a differentially treated paper on wetting. There is not recognition of the use of a coating to delay the change in appearance. The use of an indicator with paper products which are inherently water containing to retain their flexibility, is less preferred as such a carrier is unsuitable for any anhydrous water sensitive indicator material.

US 5,783,552 (Trinh) discloses tumble dryer sheets with cyclodextrin impregnation for retention of perfume activity.

U.S. Pat. No. 4,234,627, discloses the microencapsulation of fabric softener which is applied during a washing operation. No disclosure of the fabric softener protecting and coating an encapsulate, rather than being itself encapsulated is disclosed.

Papers impregnated with water sensitive compounds, 5 classically copper sulphate and cobalt chloride are well known (SU 1,269,007, Kuznetsov, by example). Use of such materials with a protective coating, or a coating with another primary efficacy or where the indicator material indicates the exhaustion of the coating are not disclosed.

In addition such preparations are designed to give ready accessibility of water for rapid use rather than delayed transport of water, solvent or similar component.

According to a first aspect of the present invention, there is provided an indicator product comprising a substrate and a colour indicator component distributed on and/or in the substrate, wherein a barrier composition is present on the substrate to substantially isolate colour indicator distributed on and/or in the said substrate from the surrounding environment. Preferably, the barrier composition forms a film or coating on the substrate which is, preferably, substantially continuous across at least one substrate area where indicator is present.

Advantageously, by the use of a barrier composition, the action of the indicator may be delayed until such time as the barrier is removed at least to the extent that at least some of the previously isolated indicator is exposed to the environment surrounding the product.

Although it is not essential for the barrier to be coated across all the surface area of the substrate, it is preferred that the barrier film be so distributed so that all the colour indicator is isolated by the film.

Preferably the barrier composition is removed from the substrate by contact with other substances or articles.

Preferably, the barrier composition is progressively 5 removed by contact with other substances or articles.

In one preferred embodiment, the barrier composition is a fabric softener.

The substrate may be any suitable material known to those skilled in the art which will preferably absorb the colour indicator and act as a substrate for the barrier composition.

is In one preferred embodiment, the substrate is a tumble dryer sheet of the type used as disposable tumble dryer sheets. The composition is then progressively removed during the drying action to gradually expose the colour indicator to the surrounding environment.

In a further embodiment, an encapsulated volatile liquid may also be distributed on and/or in the substrate and isolated by the said barrier composition.

Preferably, the barrier composition is hydrophobic and, in such cases, the colour indicator is water sensitive.

A hydrophobic coating is particularly advantageous where the colour indicator component is water sensitive. In this way water transfer across the barrier is prevented either from the indicator to the surrounding environment or from the surrounding environment to the indicator.

In one preferred embodiment, the colour indicator component is sensitive to water loss. Such an indicator may be used for tumble dryer applications. In such an embodiment, the barrier composition is progressively removed in use by contact with the dryer load until the indicator is directly exposed to the atmosphere in the dryer, resulting in loss of water or other volatile component from the indicator and a resultant colour change. Such a colour change thus indicates that the softener has been exhausted and the cycle is complete.

In another embodiment, the barrier composition is hydrophobic and the indicator is sensitive to water gain. Such a combination could be used for a moisturising wipe where the hydrophobic coating is a skin cream or the like. Exposure to water from the skin or the general environment is will cause the indicator to absorb moisture and cause a colour change to indicate that the hydrophobic coating has been exhausted.

In a still further embodiment, other components are 20 entrapped by the film such as fragrance components which are thereby released once the barrier composition has been at least partially removed. This may take place directly or as a result of a secondary action due to exposure of the fragrance component to water, heat, etc in the general environment or by contact with an external substance.

A binder may be utilised to bind the colour indicator to the substrate. Similarly, suitable binders may be used to bind any of the other components to the substrate although it is preferred that the barrier composition is self adhering to the substrate, at least in use.

According to a further aspect of the present invention, there is provided a method of producing an indicator product comprising the steps of:- (a) distributing a colour indicator component on and/or in a substrate; (b) adding a barrier composition to the substrate to substantially isolate colour indicator distributed on and/or in the said substrate from the surrounding environment.

Preferably, an encapsulated volatile liquid is distributed on and/or in the substrate prior to step (b).

Preferably, the second aspect of the invention may incorporate any one or more of the preferred features of the first aspect detailed above.

Preferably, the present invention relates to a porous sheet like substrate in which a water sensitive substance is entrained, which sheet is then coated with a substantially hydrophobic material, such that when the hydrophobic material becomes exhausted in the process of using the article the entrained substance can change its hydration state and thereby indicate by means of a change in colour that the coating material has been dissipated.

Preferably, the barrier composition has a melting point above 370C. The barrier composition may form a liquid film during use temperatures and be applied to the substrate either as a solid or liquid. Preferably, the barrier composition is in the liquid phase during normal use in a tumble dryer.

The invention is particularly suitable for fabric conditioning tumble dryer sheets in which the hydrophobic coating is predominantly a hydrophobic cationic surfactant and the indicator changes colour on the loss of water. The invention is also suitable for a moisturising wipe wherein the hydrophobic coating is skin cream or similar and the indicator changes colour on the absorption of water. Furthermore a sheet in which such effects are combined with an odiferous encapsulate which gives a final fragrance boost on exhaustion of the coating, particularly by the incorporation of a water sensitive pro-fragrance, is particularly preferred as this counteracts consumer disappointment at the further inefficacy of the product.

Preferably, the substrate is in sheet form, with entrained colour indicator that exhibits a colour change on the loss or gain of a volatile component. The volatile component may be, but is not necessarily, water. Preferably, the barrier film or coating is a substantially hydrophobic coating which is delivered to articles, at, preferably, above ambient temperature, to which it is contacted. In this manner, it is substantially removed exposing the colourant to an atmosphere of differential volatile component concentration thus bringing about a change in colour as ap indication that the substantially hydrophobic coating material has been substantially distributed on the surrounding surfaces.

A preferred embodiment of the invention is a tumble dryer sheet with entrained colourant and a barrier composition comprising hydrophobic fabric softener component. The sheet may optionally contain an entrained encapsulate of volatile liquid, preferably a fragrance or volatile silicone, which is also, preferably, isolated by the barrier composition from the surrounding environment until the latter has been removed to the extent that the encapsulate is no longer isolated from the surrounding environment.

The invention is also suitable for use with emollient skin conditioning sheets wherein the sheet contains entrained colourant and a coating of substantially hydrophobic emollient material as the barrier composition. The sheet may also optionally contain an entrained encapsulate of volatile liquid, preferably a fragrance or volatile silicone, as hereinbefore described.

Alternatively, the encapsulate may be coated directly with the barrier composition. In a further alternative, the encapsulate may be suspended in the barrier composition.

Colourimetric indicator comnound is The preferred colourimetric indicators are Copper Sulphate or Cobalt Chloride. These materials will typically be entrained in the substrate, such as a fabric, relying on simple physical entrapment or with the aid of a polymeric adjuvant. Particle sizes of between 100 and 1Ogm are preferred. In particular the colourimetric indicator may be applied in a hydrated form and optionally dried in situ on the sheet or similarly the indicator may be added as a solution. Alternatively fine indicator particles may be mixed to a paste like composition with polyvinyl alcohol_ or other binder and, optionally, an inert filler such as sodium sulphate or sodium chloride. Such a paste can be injected on to the sheet either as localised patches or in a pattern form such as to give a textual message. In such cases, the barrier composition may be applied optionally only over the areas entrained with colourant or over a greater area as required.

Other colourimetric indicators are disclosed in SU 1,269,007 and include dyes which change their shade depending upon the concentration of water present. Such dyes as change their colour by 2 delta E units or more, preferably by 5 units or more on the CIElab colour scale as known in the art and described in 'Colour Physics for Industry, R McDonald, Society of Dyers and Colourists, 1987 are considered suitable. Such a colour change should occur on a change in their water content from 0.5% to 500% water by weight (i.e. dry to very concentrated solution). Suitable materials are as described in the Colour Index, Society of Dyers and Colourists (UK) and include example materials of Colour index numbers 10020, 13015, 10316, 13065, 14720, 14600, 14700, 14720, 14815, 15510, 15620, 15850, 15980, 15985, 16035, 16150, 16155, 16135, 16230, 16255, 16290, 17200, 18050, 18130, 18690, 18736, 18820, 18950, 18956, 19140, 20470, 24790, 27290, 27755, 28440, 40215, 42051, 42052, 42053. It is noted that the person skilled in the art would choose the crystalline form of such materials so as to best facilitate the observation of the shade change consistent with the hydration and drying of these materials.

Delivery system The present invention also relates to improvedsolid dryer-activated fabric softener compositions. The compositions may be incorporated into articles of manufacture. The compositions may contain small particle encapsulates in the form of particles (including, where appropriate, agglomerates, pellets, and tablets of said particles). Such compositions contain from about 10% to about 95% of fabric softening agent and at least an effective amount of said small particle size liquid encapsulate preferably with a volatile component, preferably, water sensitive coating.

Sheet material Substrate In preferred embodiments, the present invention encompasses a substrate comprising articles of manufacture. Representative articles are those that are adapted for use to provide unique perfume benefits and to soften fabrics in an automatic laundry dryer, of the types disclosed in U.S. Pat. Nos. 3,989,631 Marsan, issued Nov. 2, 1976; 4,055,248, Marsan, issued Oct. 25, 1977; 4,073,996, Bedenk et al., issued Feb. 14, 1978; 4,022,938, Zaki et al., issued May 10, 1977; 4,764,289, Trinh, issued Aug. 16, 1988; 4,808,086, Evans et al., issued Feb. 28, 1989; 4,103,047, Zaki et al., issued Jul. 25, 1978; 3,736,668, Dillarstone, issued Jun. 5, 1973; 3,701,202, Compa et al., issued Oct. 31, 1972; 3,634,947, Furgal, issued Jan. 18, 1972; 3,633,538, Hoeflin, issued Jan. 11, 1972; and 3,435,537, Rumsey, issued Apr. 1, 1969; and 4,000,340, Murphy et al., issued Dec. 28, 1976, all of said patents being incorporated herein by reference.

Suitable materials which can be used as a substrate in the invention herein include, among others, sponges, paper, and woven and non-woven cloth, all having the necessary absorbency requirements of adsorbing more than its own weight of softener composition. Woven substrates comprise a typical warp and weft, the materials of warp and weft optionally being of differential composition and weight of yarn. This allows one fabric orientation to be the primary adsorbent and the other the primary strength imparting component. Alternatively such weaves may utilise alternating strands of materials in the warp and/or weft to achieve a similar purpose. A combined cloth of cotton and polyester is particularly suitable.

The preferred non-woven cloth substrates can generally be defined as adhesively bonded fibrous or filamentous products having a web or carded fibre structure, or comprising fibrous mats in which the fibres or filaments are distributed haphazardly or in random or pseudo random array with partial orientation of the fibres. Such a non woven mat may be bonded by laying down a hot f ibre on itself, as a separate process of spot welding or in continuous welded lines from a heated roller or as regular pattern produced in a similar manner. The latter may also include a textual message or similar. The f ibres or filaments can be natural (eg. wool, silk, jute, hemp, cotton, lene, sisal or ramie and mixtures thereof) or synthetic (eg. cellulose ester, polyvinyl derivatives, polyethylene, polypropylene, rayon, polyamides, and polyesters and mixtures thereof). Preferred polyester non-woven fabric substrates are prepared from a polyester fibre having a denier of from 1 to 200. The preferred adsorbent properties are obtained by building up the thickness of the cloth, ie. by superimposing a plurality of carded webs or mats to a thickness adequate to obtain the necessary absorbent properties, or by allowing a sufficient thickness of the fibres to deposit on the screen. Any diameter or denier of the fibre (generally up to 10 denier) can be used, inasmuch as it is the free space between each fibre that makes the thickness of the cloth directly related to the absorbent capacity of the cloth, and which, further, makes the non-woven cloth especially suitable for impregnation with a composition by means of capillary or intersectional action. Thus, any thickness necessary to obtain the required absorbent capacity can be used.

Papers suitable for the purpose preferably utilise softwood fibres with a fibre length of preferably greater than 1mm. more preferably greater than 2mm, most preferably with substantial proportion of length greater than 4mm. Spruce fibres are particularly preferable. in addition or alternatively polyester fibres may be commingled to obtain suitable paper strength and durability. 5 Typical articles of manufacture of this type include articles comprising:

I. a fabric conditioning composition comprising:

i. from about 30% to about 95% of normally solid, dryer softenable material, typically fabric softening agent; and is ii. an effective amount, preferably from about 0.25% to about 10%, of colourimetric indicator, as described hereinbefore; iii. optionally, an effective amount, preferably from about 0.25% to about 30%, of encapsulated volatile liquid having a primary particle size of less than about 25 microns, as described hereinbefore; II. a dispensing means which provides for release of an effective amount of (i) including, optionally, an effective amount ofiii, sufficient to effect volatile softener delivery and, in the case of iii, odour release, to fabrics in an automatic laundry dryer at automatic laundry dryer operating temperatures, e.g., from about 35 degree. C. to 115 degree. C. When the dispensing means is a flexible substrate, e.g., in sheet configuration, the fabric conditioning composition is releasably affixed on the substrate to provide a weight ratio of conditioning composition to dry substrate ranging from about 10:1 to about 0.5:1, preferably from about 5:1 to about 1:1.

The invention also comprises the method of use of such an article of manufacture utilising said colourimetric indicators, optionally encapsulated fragrance or softening agent and subsidiary components.

Softener comiDonents 10 The term "fabric softening agent" as used herein includes cationic and nonionic fabric softeners used alone and also in combination with each other. A preferred fabric softening agent of the present invention is a mixture of cationic and nonionic fabric softeners. Examples of fabric softening agents that are especially useful in the substrate articles are the compositions described in U.S.

Pat. Nos. 4,103,047, Zaki et al., issued Jul. 25, 1978; 4,237,155, Kardouche, issued Dec. 2, 1980; 3,686,025, Morton, issued Aug. 22, 1972; 3,849,435, Diery et al.,_ issued Nov. 19, 1974; and U.S. Pat. No. 4,073, 996, Bedenk, issued Feb. 14, 1978; said patents are hereby incorporated herein by reference. Another preferred type of fabric softener is described in detail in U.S. Pat. No.

4,661,269, Toan Trinh, Errol H. Wahl, Donald M. Swartley and Ronald L. Hemingway, issued Apr. 28, 1987, said_ patent being incorporated herein by reference. Examples of nonionic fabric softeners are the sorbitan esters, C.sub.12 -C.sub.26 fatty alcohols, and fatty amines.

More biodegradable fabric softener compounds can be desirable. Biodegradability can be increased, e.g., by incorporating easily destroyed linkages into hydrophobic groups. Such linkages include ester linkages, amide linkages, and linkages containing unsaturation and/or hydroxy groups. Examples of such fabric softeners can be - 14 '- found in U.S. Pat. Nos. 3,408,361, Mannheimer; 4,709,045, Kubo et al; 4,233,451, Pracht et al.; 4,127,489, Pracht et al.; 3,689,424, Berg et al.; 4,128,485, Baumann et al.; 4,161,604, Elster et al.; 4,189,593, Wechsler et al.; and 4,339,391, Hoffman et al., said patents being incorporated herein by reference. A preferred article of the present invention includes a fabric treatment composition which comprises from about 0.5% to about 30%, preferably from about 1% to about 10%, more preferably from about 1.5% to about 5%, of encapsulated volatile liquid, as discussed hereinbefore, and from about 30% to about 95%, preferably from about 40% to about 90%, of fabric conditioning (softening) agent. Preferably, said fabric softening agent is selected from cationic and nonionic fabric softeners and mixtures thereof. Preferably, said fabric softening agent comprises a mixture of about 5% to about 95% of a cationic fabric softener and/or about 5% to about 95% of a nonionic fabric softener by weight of said fabric treatment agent.

The selection of the components is such that the. resulting fabric treatment composition has a melting point above about 37 degree. C. and is flowable at dryer operating temperatures.

Fraqrance comDonents The perfume ingredients and compositions of this invention are the conventional ones known in the art. Selection of any perfume component, or amount of perfume, is based on aesthetic considerations. Suitable perfume compounds and compositions can be found in the art including U.S. Pat. Nos. 4,145,184, Brain and Cummins, issued Mar. 20, 1979; 4,209,417, Whyte, issued Jun. 24, 1980; 4,51S,705, Moeddel, issued May 7, 1985; and 4,152,272, Young, issued May 1, 1979, all of said patents being incorporated - is - herein by reference. Many of the art recognised perfume compositions are relatively substantive, as described hereinafter, to maximise their odour effect on substrates. However, the use of cyclodextrin/perfume complexes may be used to improve substantivity and longevity of perfume. A substantive perfume is one that contains a sufficient percentage of substantive perfume materials so that when the perfume is used at normal levels in products, it deposits a desired odour on the treated fabric. In general, the degree of substantivity of a perfume is roughly proportional to the percentage of substantive perfume material used. Relatively substantive perfumes contain at least about 1%, preferably at least about 10%, substantive perfume materials. Substantive perfume is materials are those odorous compounds that deposit on substrates via the treatment process and are detectable by people with normal olfactory acuity. Such materials typically have vapour pressures lower than that of the average perfume material. Also, they typically have molecular weights of about 200 or above, and are detectable at levels below those of the average perfume material. Perfumes can also be classified according to their volatility, as mentioned hereinbefore. The highly volatile, low boiling, perfume ingredients typically have boiling points of about 250 degree. C. or lower. Many of the more moderately volatile perfume ingredients are also quickly lost. For example, substantially all of such perfumes are lost in the drying cycle of a typical laundry process. The moderately volatile perfume ingredients are those having boiling points of from about 250 degree. C. to about 300 degree. C. The less volatile, high boiling, perfume ingredients referred to hereinbefore are those having boiling points of about 300.degree. C. or higher. A significant portion of even these high boiling perfume ingredients, considered to be highly substantive, can be lost, during a laundry drying cycle, and it is desirable to have means to retain more of these ingredients on the fabrics. Many of the perfume ingredients as discussed hereinafter, along with their odour characters, and their physical and chemical properties, such as boiling point and molecular weight, are given in "Perfume and Flavour Chemicals (Aroma Chemicals)," Steffen Arctander, published by the author, 1969, incorporated herein by reference. Examples of the highly volatile, low boiling, perfume ingredients are: anethole, benzaldehyde, benzyl acetate, benzyl alcohol, benzyl formate, iso-bornyl acetate, camphene, cis-citral (neral), citronellal, citronellol, citronellyl acetate, para-eymene, decanal, dihydrolinalool, dihydromyrcenol, is dimethyl phenyl carbinol, eucalyptol, geranial, geraniol, geranyl acetate, geranyl nitrile, cis-3-hexenyl acetate, hydroxycitronellal, d- limonene, linalool, linalool oxide, linalyl acetate, linalyl propionate, methyl anthranilate, alpha-methyl ionone, methyl nonyl acetaldehyde, methyl phenyl carbinyl acetate, laevo-menthyl acetate, menthone, iso-menthone, myrcene, myrcenyl acetate, myrcenol, nerol, neryl acetate, nonyl acetate, phenyl ethyl alcohol, alpha-pinene, beta-pinene, gamma-terpinene, alpha- terpineol, beta-terpineol, terpinyl acetate, and vertenex (para-tertiary-butyl cyclohexyl acetate). Some natural oils also contain large percentages of highly volatile perfume ingredients. For example, lavandin contains as major components: linalool; linalyl acetate; geraniol; and citronellol. Lemon oil and orange terpenes both contain about 95% of d-limonene. Examples of moderately volatile perfume ingredients are: amyl cinnamic aldehyde, iso-amyl salicylate, beta-caryophyllene, cedrene, cinnamic alcohol, coumarin, dimethyl benzyl carbinyl acetate, ethyl vanillin, eugenal, iso-eugenol, flor acetate, heliotropine, 3-cis-hexenyl salicylate, hexyl salicylate, lilial (para- tertiarybutyl -alpha -methyl hydrocinnamic aldehyde), gamma-methyl ionone, nerolidol, patchouli alcohol, phenyl hexanol, beta-selinene, trichloromethyl phenyl carbinyl acetate, triethyl citrate, vanillin, andveratraldehyde. Cedarwood terpenes are composed mainly of alpha-cedrene, beta-cedrene, and other C.sub.15 H.sub.24 sesquiterpenes. Examples of the less volatile, high boiling, perfume ingredients are: benzophenone, benzyl salicylate, ethylene brassylate, 9 a 1 a X 0 1 i d e (1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethyl-cyclo-pent a-gama-2benzopran), hexyl cinnamic aldehyde, lyral (4 - (4 -hydroxy- 4 -methyl pentyl)-3-cyclohexene-lo-carboxaldehyde), methyl cedrylone, methyl dihydro jasmonate, methyl -beta - naphthyl ketone, musk indanone, musk ketone, musk tibetene, and phenylethyl phenyl acetate.

EncalDsulation 20 As used herein the term encapsulate refers to a particulate material in which comprises a liquid or substantially liquid phase or phases surrounded completely by a barrier or membrane which is impermeable to the said liquid phase material(s).

The encapsulated liquid may be any volatile liquid such as those with a detergent function examples being:

Cyclic Silicones, Volatile silicones, Polydimethyl siloxanes Liquid surfactants (eg Synperonic A3, A3 {ICI}) Bleach precursor (eg Glycerol triacetate) Antifoam (e.g. poly dimethyl siloxane) Perfumes Perfume precursors (e.g. esters, enols of volatile aldehydes and ketones) also mixtures of the above or in combination with solid components such that the viscosity of the encapsulate remains essentially liquid, i.e. with a viscosity of less than 10 Pascal seconds at 20s-1 shear rate (as for example measured by a Haake viscometer with a cylindrical measuring cup and bob). The encapsulating material may be any material which gives a particulate

encapsulate where no part of the encapsulated liquid can directly contact its surrounding. It is recognised that in commercial production some encapsulate material will inevitably remain unencapsulated and some coating remain unused. This invention does not therefore rely on the success of the encapsulation procedure or of the amount or proportion of any liquid or liquids present that have been encapsulated but on the presence of encapsulated material per se.

Suitable encapsulating materials are illustrated by the following nonlimiting examples:

organic polymers Addition polymers - e.g. Poly Vinyl ethers, esters,a m i d e s, carboxylates, maleates, methacrylates, acrylates, alcohols, acetates and copolymers thereof.

- Condensation polymers - eg Poly esters, and urethanes, gelatin, xanthan gums, guar gum, alginates.

The encapsulates will typically consist of largely 35 spherical structures filled at least in part with the desired liquid, the remainder being either liquid vapour, air, nitrogen, argon or similar. These structures may consist of aggregates of multiples of these primary structures as may typically be produced during the encapsulation process.

The encapsulates may typically be produced by emulsifying the desired liquid in another liquid, the introduction of an amphiphillic polymer or monomer which will reside largely at the interface of the droplets. This emulsion orsuspension is then reacted to polymerise and / or cross link to form suspended encapsulate which is then used as such or removed by filtration, centrifugation or other suitable means.

is The invention is also suitable for use in an emollient' hand cleansing sheet or similar in which case a softening component will typically consist of a hydrophobic emollient oil.

Emollient oils Suitable emollient oils can be chosen from the wide range known in the art, for example Lanolin. Esters with a combined alkyl chain length of between 20 and 40 are particularly preferred. Examples include PELEMOL CA, Cetyl Acetate, PELEMOL CL, Cetyl Lactate, PELEMOL SPO, Cetearyl Octanoate, PELEMOL 168, Cetyl Octanoate, PELEMOL CP, Cetyl Palmitate, PELEMOL CR, Cetyl Ricinoleate, PELEMOL 1215L, C12-15 Alkyl Lactate, PELEMOL 300B, C20-40 Alkyl Behenate, PELEMOL DO, Decyl Oleate, PELEMOL DES, Diethyl Sebacate, PELEMOL HAB, Dihydroabietyl Behenate, PELEMOL DIA, Diisopropyl Adipate, PELEMOL DIPS, Diisopropyl Sebacate, PELEMOL DNPA, Dipropyl Adipate, PELEMOL DOA, Dioctyl Adipate, PELEMOL DOM, Dioctyl Maleate, PELEMOL DICA, Diisocetyl Adipate, PELEMOL G7A, Glycereth-7 Triacetate, all materials ex Pheonix chemicals, Pelemol is a Trademark.

Such materials may be used alone or in combination and may include subsidiary components such as colourants, dissolved fragrance, bactericides, other preservatives, solvents anti-ageing ceramides and other materials known in the art for such purposes.

Substrate In a preferred substrate article embodiment, the fabric treatment compositions are provided as an article of manufacture in combination with a dispensing means such as a flexible substrate which effectively releases the. composition in an automatic laundry (clothes) dryer or by sustained manual use. Such dispensing means can be designed for single usage or for multiple uses. The dispensing means can also be a "carrier material" that releases the fabric softener composition and then is dispersed and/or exhausted from the dryer. The dispensing means will normally carry an effective amount of fabric treatment composition. Such effective amount typically provides sufficient fabric conditioning agent and/or anionic polymeric soil release agent for at least one treatment of a minimum load in an automatic laundry dryer. Amounts of fabric treatment composition for multiple uses, e.g., up to about 30, can be used. Typical amounts for a single article can vary from about 0.25 g to about 100 g, preferably from about 0.5 g to about 20 g, most preferably from about 1 g to about 10 g. One such article comprises a sponge material releasably enclosing enough fabric treatment composition to effectively impart fabric soil release and softness benefits during several cycles of clothes. This multi-use article can be made by filling a hollow sponge with about 20 grams of the fabric treatment composition. Other devices and articles suitable for dispensing the fabric treatment composition 5 into automatic dryers include those described in U.S. Pat. Nos. 4,103,047, Zaki et al., issued Jul. 25, 1978; 3,736,668, Dillarstone, issued Jun. 5, 1973; 3,701,202, Compa et al., issued Oct. 31, 1972; 3, 634,947, Furgal, issued Jan. 18, 1972; 3,633,538, Hoeflin, issued Jan. 11, 1972; and 3,435,537, Rumsey, issued Apr. 1, 1969. All of these patents are incorporated herein by reference. Highly preferred paper, woven or non-woven "absorbent" substrates useful herein are fully disclosed in U.S. Pat. No. 3,686,025, Morton, issued Aug. 22, 1972, incorporated herein by reference. It is known that most substances are able to absorb a liquid substance to somedegree; however, the term "absorbent" as used herein, is intended to mean a substance with an absorbent capacity (i.e., a parameter representing a substrate's ability to take up and retain a liquid) from 4 to 12, preferably 5 to 7, times its weight of water.

Method of product application The substrate embodiment of this invention can be used for imparting the above-described fabric treatment composition to fabric to provide odour control and/or perfume effects and/or softening and/or antistatic effects to fabric in an automatic laundry dryer comprises:

commingling pieces of damp fabric by tumbling said fabric under heat in an automatic clothes dryer with an effective amount of the fabric treatment composition, at least the continuous phase of said composition having a melting point greater than about 37.degree. C.

Subsidiary comiDonents Well known optional components included in fabric conditioning compositions are narrated in U.S. Pat. No.

4, 103, 047, Zaki et al., issued Jul. 25, 1978, for "Fabric Treatment Compositions," incorporated herein by reference. Another preferred additional ingredient in the compositions herein is free perfume, other than the perfume which is present as or in any comp lex or as a properfume. A pro-perfume being one which releases an active oderific substituent or component on chemical reaction induced by a condition peculiar to an in-use condition, which is also very useful for imparting the odour benefits. Uncomplexed perfume is preferably present at a level of from about 0.10% to about 10% by weight of the total. For example, perfume delivery both via tree perfume and encapsulates, in solid, dryer-activated, fabric conditioning compositions in laundry fabric dryers is desirable in two ways. Product malodours can be covered by the addition of free perfume to the softener composition to obtain a more preferred product odour, and complexed perfume can be transferred onto fabric with the softener actives in the laundry fabric dryer to provide better in-wear fabric odour. (Preferably, such uncomplexed perfume comprises at least about 1%, more preferably at least about 10% by weight of said uncomplexed perfume, of substantive perfume materials.) Encapsulated fragrances as described in the copending application filed by the applicants at the UK Patent office with the same priority date as this application may also be included.

The following are non limiting examples Three colourants were prepared Colourant A - Copper Sulphate, Average particle size 100pm Colourant B Cobalt Chloride, Average particle size 125pm Colourant C Iragon Blue ABL 80 ex Ciba Each colourant was dusted on to the sheet material to a weight of about 7% and then sprayed with 0.1g square centimetre of polyvinyl alcohol MW 50,000 in ethanol (30% w/w) binder and left to air dry.

All chemicals were ex Aldrich Chemical Co. unless stated otherwise is Coating-of tumble dyer sheets Ditallowalkyldi-methylammonium sulphate (ex Sherex Chemical Co.) is melted at about 90.degree. C. and then 20 sprayed on to the pre-prepared sheet material at a distance of about 15cm at such a rate as to avoid heating the sheets above 250C. The material was added to form a total of between 60 and 65% weight/weight of final sheet.. The appropriate stages were omitted to prepare the various 25 variants tabulated.

Coatinq of cosmetic emollient wiDe The sheet with colourant was first dryed at 900C to.

constant weight. Lanolin ex Aldrich is melted at about 120 degree. C. and then sprayed on to the pre-prepared sheet material at a distance of about 15cm at such a rate as to avoid heating the sheets above 500C. The material was added to form a total of between 50 and 55% weight/weight of final sheet. The appropriate stages were omitted to prepare the various variants tabulated.

Textile washing and conditioning 5 A dryer (White knight model Sensodry on high setting) was loaded with 4kg of wet terry towelling pre-washed (Hotpoint 1200 washing machine with spin speed of 120Orpm). The wash was performed using soft water (60Fh) and 30g of sodium silicate and 5g of Synperonic A7 (ex ICI) surfactant in 900C main wash cycle.

A single tumble dryer sheet weighing 25g was added to the dryer and the load dried until the weight of the cloth was reduced in weight to less than 2.3kg (i.e. dry to the touch).

The odour of two separate pieces of towelling was then scored on a scale of 0 to 5. 0 no odour, 5 is very strong odour, by five assessors. The scores were then averaged and rounded to the first decimal.

Colour measurement The colour of the sheets was measured using a MeBeth Colour Eye 3100 colourimeter using the CIElab L, a, b (CIE 1976) colour space measurements. The difference in the colour in terms of delta E ab (i.e. the square root of the sum of the squares of the differences in the L, a and b measures before and after the use of the product). was then determined for an area of the sheet. Results were rounded to the first decimal. Each reading was an average of five separate readings.

- 25 Tumble dryer sheet Colour change, delta E, readings evaluation AE After 5 minutes drying at which time the load was still 5 predominantly wet. Substrate Conditione Colourant Colourant Colourant r only A only A and A and fabric fabric conditione conditione r r on separate halves of the sheet Paper 0 >10 0.1 >10 Non-woven 0 >10 0.1 >10 polyester Knitted 0 >10 0.2 >10 cotton Read from most intensely coloured part of the sheet.

AE After drying.

Substrate Conditione Colourant Colourant Colourant r only A only A and A and fabric fabric conditione conditione r r on separate halves of the sheet Paper 0 >10 >10 >10 Non-woven 0 >10 >10 >10 polyester Knitted 0 >10 >10 >10 cotton Read from most intensely coloured part of the sheet.

Cosmetic emollient wipe Each sheet type was used by ten panellists who had previously washed their hands in a 10% solution of Synperonic A7 (ex ICI) surfactant, thoroughly rinsed. one use of the sheet constituted placing the sheet between the palm of one hand resting on the back of the other and rotating the hands to swap the upper and lower hands in a stereotypical hand wringing motion for a specified number of passes. The colour of the sheet was measured before and af ter.

AE After five hand movements.

Substrate Emollient Colourant Colourant Colourant only A only A and A and emollient emollient on separate halves of the sheet Paper 0 >10 4.0 >10 Non-woven 0 >10 3.1 >10 polyester Knitted 0 >10 4.3 >10 cotton Read from most intensely coloured part of the sheet.

AE After ten hand movements.

Substrate Emollient Colourant Colourant Colourant only A only A and A and Emollient emollient on separate halves of the sheet Paper 0 >10 >10 >10 Non-woven 0 >10 >10 >10 polyester Knitted 0 >10 >10 >10 cotton Read from most intensely coloured part of the sheet.

Emollient loss was determined by soxhlet extraction of the sheet with acetone, drying the residue taking this as the residual emollient after deducting the weight of encapsulate used and hence extracted.

Emollient efficacy, % loss of emollient from sheet Initial after 5 after 10 after 20 hand hand hand movement movements movements S Sheet only 0 0 0 0 Sheet with 0 0 0 0 colourant A Sheet with 0% 58% 75%. 81% emollient and colourant A This demonstrates the apposite nature of the colour change in relation to the potential residual emollient efficacy of the sheet.

AE After five hand movements.

Substrate Emollient Colourant Colourant Colourant only B only B and B and Emollient Emollient hand 10 hand movements movements Paper 0 >10 1.8 9.3 Non-woven 0 >10 2.0 >10 polyester Knitted 0 >10 1.4 8.1 cotton Read from most intensely coloured part of the sheet.

AE After ten hand movements.

Substrate Emollient Colourant Colourant Colourant only C only C and C and Emollient Emollient hand 10 hand movements movements Paper 0 >2 0.7 >2 Non-woven 0 >2 0.3 >2 polyester Knitted 0 >2 0.4 >2 cotton The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated. otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment (s). The invention extends to anynovel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims (29)

1 An indicator product comprising a substrate and a colour indicator component distributed on and/or in the substrate, wherein a barrier composition is present on the substrate to substantially isolate colour indicator distributed on and/or in the said substrate from the surrounding environment.

2. An indicator product according to claim 1, wherein the barrier composition forms a film or coating on the substrate, at least in use.

3. An indicator product according to claim 2, wherein the film or coating is substantially continuous across at least one substrate area where indicator is present.

4. An indicator product according to any preceding claim, wherein the barrier composition is coated across all the surface area of the substrate so that substantially all the colour indicator is isolated by the barrier composition.

5. An indicator product according to any preceding claim, wherein the barrier composition is, in use, removed from the substrate by contact with other substances or articles.

6. An indicator product according to any preceding claim, wherein the barrier composition is, in use, progressively removed by contact with other substances or articles.

7. An indicator product according to any preceding claim, wherein the barrier composition is a fabric softener.

8. An indicator product according to any preceding claim, wherein the substrate may be any suitable material known to those skilled in the art which will absorb the colour indicator and act as a substrate for the barrier composition.

9. An indicator product according to any preceding claim, wherein the substrate is a tumble dryer sheet of the type used as disposable tumble dryer sheets.

10. An indicator product according to claim 9, wherein the composition is progressively removed during the drying action to gradually expose the colour indicator to the surrounding environment in the dryer.

11. An indicator product according to any preceding claim, wherein the barrier composition is hydrophobic.

12. An indicator product according to any preceding claim, wherein the colour indicator is water sensitive.

13. An indicator product according to any preceding claim, wherein the colour indicator componentis sensitive to water loss.

14. An indicator product according to any preceding claim, wherein the barrier composition is, in use, progressively removed by contact with a dryer load until the indicator is directly exposed to the atmosphere in the dryer, resulting in loss of water or other volatile component from the indicator and a resultant colour change.

15. An indicator product according to any preceding claim, wherein the barrier composition is hydrophobic and the indicator is sensitive to water gain.

16. An indicator product according to any of claims 1-6, 8, 11-13 or 15 the substrate is a moisturising wipe.

17. An indicator product according to any of claims 1-6, 8, 11-13, 15 or 16, wherein the barrier composition is an emollient cream or the like.

18. An indicator product according to any preceding claim, wherein other active components are isolated by the barrier composition.

19. An indicator product according to claim 1, wherein the colour indicator product is distributed on the substrate to form a pattern on or in the substrate.

20. An indicator product according to claim 19, wherein the pattern is a textural message.

21. A method of producing an indicator product comprising the steps of:

(a) distributing a colour indicator component on and/or in a substrate; (b) adding a barrier composition to the substrate to substantially isolate colour indicator distributed on and/or in the said substrate from the surrounding environment.

22. A method of producing an indicator product according to claim 21, wherein an encapsulated volatile liquid is distributed on and/or in the substrate prior to step (b).

23. A method of producing an indicator product according to any of claims 21 or 22, wherein the substrate has a water sensitive colour indicator substance entrained such that, in use, once the barrier composition becomes exhausted the entrained substance can change its hydration state and thereby indicate by means of a change in colour that the coating material has been dissipated.

24. A method or an indicator product according to any preceding claim, wherein the substrate is in sheet form, with colour indicator that exhibits a colour change on the loss or gain of a volatile component.

25. A method of softening clothes comprising the steps of:

locating an indicator product according to any of claims 7-15 or 18-20 in contact with a dryer load in.

a dryer for a period of time suitable to remove at least some of the fabric softener from the substrate to the extent that at least some of the colour indicator is exposed to the environment in the dryer,

26. A method according to claim 25, wherein the exposure. effects a colour change of the indicator.

27. An indicator product as hereinbefore described with reference to the examples.

28. A method of producing an indicator product as hereinbefore described with reference to the examples.

29. A method of softening clothes as hereinbefore described with reference to the examples.