WO2005118007A1

WO2005118007A1 - Volatile composition impregnated in a porous carrier and comprising a dye as “end-of-life” indicator

Info

Publication number: WO2005118007A1
Application number: PCT/GB2005/001937
Authority: WO
Inventors: Jackie Mcinnes
Original assignee: Reckitt Benckiser UK Ltd
Current assignee: Reckitt Benckiser UK Ltd
Priority date: 2004-06-02
Filing date: 2005-05-18
Publication date: 2005-12-15
Anticipated expiration: 2006-12-02

Abstract

A product comprising a solid, porous substrate and, impregnated therein, a liquid composition having a dye dissolved therein such that, after said product has been in use, the dye precipitates causing a colour change which can act as an end-of-life indication.

Description

VOLATILE COMPOSITION IMPREGNATED IN A POROUS CARRIER AND COMPRISIN A DYE AS "END-OF-LIFE" INDICATOR

The present invention relates to a product having an end-of-life indication, particularly an air-freshening, 5 deodorising, pesticidal or insect repellent product.

The use of various devices for the diffusion of volatile compounds, for example air-freshening, deodorising, pesticidal or insect repellent compositions, into the 10 atmosphere has become increasingly popular in recent years.

For example, air-freshening devices or deodorizers are currently used in many households to mask bad odours, or to impart fragrances to the ambient air. Various types of 15 devices are known for the diffusion of volatile compounds into the surroundings. For example, spray devices, such as aerosol sprays, may be used to dispense a liquid composition into the ambient air. Other devices comprise housings enclosing the active ingredients in liquid form. Typically, 20 the diffusion of the active ingredient takes place through membranes permeable to the vapours of the active ingredient, or through a wick which is placed in a reservoir containing the ingredients .

25 Solid state devices are also known which comprise solid materials or carriers impregnated with an active ingredient. Such devices may be formed of various materials which are capable of absorbing the ingredient and subsequently releasing the ingredient into the surroundings . Examples of 30 such known materials include gels, synthetic polymer resins, and blocks of mineral material, such as plaster or silica. Solid state devices have the advantage that they are easy to handle.

According to the present invention, there is provided product comprising a solid, porous substrate and, impregnated therein, a liquid composition having a dye dissolved therein such that, after said product has been in use, the dye precipitates causing a colour change which can act as an end-of-life indication.

Preferably the product is an air freshener, deodorising, pesticidal or insect repellent product and the liquid composition is a liquid air freshener, deodorising, pesticidal or insect repellent composition.

In use, the porous substrate allows the impregnated composition to be released into the surrounding atmosphere in vapour form. After a period of use, however, the amount of composition released may cease to be optimal or even effective. For example, in the case of an air-freshening composition, the amount of air-freshener released into the surroundings may cease to be detectable by a user. Advantageously, the product of the present invention can provide a visual indication of this end-of-life point because, after the product has been in use, the dissolved dye precipitates from the product, causing a change in colour. In a preferred embodiment, the dye precipitates from the porous substrate, such that the original colour of the substrate becomes visible. This may give the used product an uneven appearance, for example, with small particles of dye unevenly spread through the structure. This uneven distribution of dye can result in a colour change that indicates the end-of-life point of the product.

The colour change caused by the precipitation of the dye may be complete at a period of from 3 to 14 days from the start of use of the product. In one embodiment, the colour change is complete at a period of from 4 to 10 days, or, for example, from 7 to 9 days. In another embodiment the colour change may occur over a longer timescale and may be complete in a period of up to 90 days or up to 30 days from the start of use of the product .

The substrate preferably has a maximum pore size of up to 100 microns, preferably, up to 90 microns, and more preferably, up to 80 microns. The mean pore size may be 5 to 80 microns, preferably, 10 to 50 microns, and more preferably, 15 to 30 microns. Pore size may be measured using microscope techniques. The substrate may have a porosity or liquid loading capacity of from 60 to 80 %, preferably, 65 to 75 %.

The substrate may be formed of any suitable material . For example, the substrate may be formed of plaster, silica and/or a ceramic material. Preferably, the substrate comprises a synthetic polymer, such as a polyolefin. Suitable polyolefins include polypropylene, high density polyethylene (HDPE) , linear low density polyethylene (LLDPE) or low density polyethylene (LDPE) . Suitable substrates include Accurel MP from Membrane GmbH. The substrate may be any colour. Preferably, however, the substrate is a colour that is readily distinguishable from the colour of the dye. In a preferred embodiment, the substrate is substantially white. The substrate may be in powder or granular form.

Alternatively, the substrate may take the form of one or more pellets or mouldings. Where pellets are employed, the pellets may have a maximum dimension of 2 cm, preferably, 1 cm. In one embodiment, the pellets have a maximum dimension of from 0.1 to 0.5 cm, for example, 0.2 to 0.3 cm. Where mouldings are employed, each moulding preferably has a maximum dimension of 5 cm or less, more preferably, 4 cm or less, and even more preferably, 3 cm or less. In one embodiment, the mouldings have a maximum diameter of from 1 to 3 cm.

Where mouldings are employed, the mouldings may be extruded through a die. The die may have any cross-section, for example, a triangular, rectangular, hexagonal, square or circular cross-section (e.g. solid or hollow cylinders) . The mouldings are preferably hollow. The walls of the hollow moulding may have a thickness of 1 to 5 mm, preferably, 1 to 3 mm, more preferably, 1 to 2 mm. In a preferred embodiment, the substrate is in the form of one or more tubes. The tube may be a moulded tube, such as an extrusion moulded tube. The tube may have a maximum length of 5 cm or less, more preferably, 4 cm or less, and even more preferably, 3 cm or less. In one embodiment, the tube has a maximum length of 1 to 3 cm. The outside diameter of the tube is preferably less than 3 cm, more preferably, less than 2 cm, for example, less than 1.5 cm. The wall of the tube may be 1 to 5 mm thick, preferably, 1 to 3 mm thick, more preferably, 1 to 2 mm thick. In a particular embodiment, the tube has a length of approximately 10 mm, an outside diameter of approximately 8.5 mm and a wall thickness of 1.5 mm.

The substrate is impregnated with a liquid composition, for example an air-freshening, deodorising, pesticidal or insect repellent composition. Preferably, the liquid composition (and the dye dissolved therein) is evenly distributed throughout the substrate. Thus, before the product has been used, it preferably has a uniform appearance (e.g. it is of a single uniform colour) . Once impregnated, the liquid composition may fill the loading capacity of the substrate by at least 85 %, preferably, at least 90 %, more preferably, at least 95 %, yet more preferably, at least 97%, and even more preferably, at least 99% . Thus, the liquid composition may form 60 to 90 weight % of the overall weight of the impregnated substrate, preferably, 65 to 75 weight %, more preferably, 68 to 73 weight % (e.g. approximately 70 weight %) . With use, at least a portion of the impregnated liquid composition will evaporate from the substrate.

The liquid composition may comprise at least 70 weight %, preferably, at least 90 weight %, more preferably, at least 95 weight %, for example, at least 99 weight % of an active ingredient or desired base, for example an air- freshening, deodorising, pesticidal and/or insect repellent base . Where an air-freshening composition is employed, the composition includes an air-freshening or perfume base. Any perfume base that is currently used in perfumery may be employed. Thus, the perfume base may be formed of discreet chemicals. More often, however, the base will be a mixture of volatile liquid ingredients of natural or synthetic origin. The nature of these ingredients may be determined with reference to specialized books of perfumery, such as "Perfume and Flavour Chemicals" (S. Arctander, Montclair N.J., USA 1969), "Perfumery" (Wiley-Intersciences, New York, USA 1994) or similar references. Examples of specific perfume bases include perfumes from Firminech, such as Pearl River Part A: 175983 HN and Pearl River Part B: 164499 NI . Mixtures of one or more perfume bases may be employed. For example, mixtures of two or three perfume bases may be employed.

The perfume base may form at least 70 weight % of the liquid composition. Preferably, the base forms at least 90 weight %, more preferably, at least 95 weight %, for example, at least 99 weight % of the liquid composition.

A perfume base may also be included in any deodorising, pesticidal or insect repellent composition employed. The amount of perfume base required in these circumstances can readily be determined by a skilled person.

Where a deodorising composition is employed, the composition includes a deodorising base. Deodorising bases are well-known to those skilled in the art. Any suitable deodorising base may be used. The deodorising base may form at least 70 weight % of the liquid composition. Preferably, the base forms at least 90 weight %, more preferably, at least 95 weight %, for example, at least 99 weight % of the liquid composition.

Where a pesticidal composition is employed, the composition includes a pesticidal base. Pesticidal bases are well-known to those skilled in the art. Any suitable pesticidal base may be used.

The pesticidal base may form at least 70 weight % of the liquid composition. Preferably, the base forms at least 90 weight %, more preferably, at least 95 weight %, for example, at least 99 weight % of the liquid composition.

Where an insect repellent composition is employed, the composition includes an insect repellent base. Insect repellent bases are known to those skilled in the art. Any suitable insect repellent base may be employed.

The insect repellent base may form at least 70 weight % of the liquid composition. Preferably, the base forms at least 90 weight %, more preferably, at least 95 weight %, for example, at least 99 weight % of the liquid composition.

The product of the present invention may also have other uses. For example the liquid composition may be a cleaning solvent, such as a dry cleaning fluid. The end-of- life indication will show when the cleaning solvent has been fully used. The liquid composition may also be a solvent without any separate utility apart from the ability to evaporate. In this instance the product will simply act as a timing device. The product can be incorporated in or associated with another device where timing is desired, for example with another air freshener such as an air freshener solvent of a trade mark Crystal Air by Reckitt Benckiser pic. The product could also be used with, for example, other air fresheners, pest control devices, tumble dryer products and anti-lime scale sachets in washing machines.

A further possibility is for the liquid composition to be a composition having a health benefit. For instance the liquid composition could be a composition comprising a eucalyptus composition intended to be used by a subject with breathing difficulties who will inhale the eucalyptus composition.

The product of the present invention may be reused. Thus after the product has been used and the dye precipitates, the product can be reimpregnated with the liquid composition, particularly if the liquid composition is a liquid air freshening, deodorising or pesticidal or insect repellent composition. The reimpregnation may, if desired, be carried out by a consumer.

Preferably, the liquid composition, especially an air- freshening, deodorising, pesticidal or insect repellent composition comprises 0 to 25 weight % water, more preferably, 0 to 10 % water, for example, 0 to 5 % water.

The composition is preferably a non-aqueous solution. In a preferred embodiment, the composition is anhydrous. The product of the present invention comprises a dye that is dissolved in the liquid composition, especially an air freshening, deodorising, pesticidal or insect repellent composition. Examples of suitable dyes include monoazo dyes, diazo dyes, anthraquinone dyes and methine dyes. Preferably, the dye is a metal-free solvent dye.

Specific examples of dyes which may be used include

Chemical Characterization Trade Names

CI. Solvent Red 27 Fat Red 5B-02 (Clariant) CI. Solvent Red 111 Sandoplas Red PFS (Clariant) CI. Solvent Yellow 14 Fat Orange R-01 (Clariant)

CI. Solvent Yellow 93 Sandoplast Yellow 3G (Clariant)

CI. Solvent Violet 13 Iragon Violet SV113 (Ciba)

C . I . Solvent Green 3 Iragon Green SGR3 (Ciba)

CI. Solvent Green 28 Sandoplast Green G (Clariant)

CI. Solvent Blue 104 Sandoplast Blue 2B (Clariant)

CI. Solvent Red 3 Fat Brown B (Clariant)

CI. Solvent Violet 37 Sandoplast Violet FBL (Clariant)

CI. Solvent Red 92 Savinyl Scarlet RLS (Clariant)

The dyes may be used individually. Alternatively, mixtures of one or more dyes may be employed. For example, mixtures of two or three dyes may be used. The dye may be used in an amount of up to 0.15 weight %, preferably, up to 0.07 weight %, more preferably, up to 0.05 weight %, for example, up to 0.03 weight % of the liquid composition, especially an air freshening, deodorising, pesticidal or insect repellent composition. Preferably, the liquid composition comprises at least 0.0001 weight % dye. In one embodiment, 0.0002 to 0.025 weight %, for example, 0.002 to 0.018 weight % dye is employed in the liquid composition.

The product may be in powder or granular form. Alternatively, the product may take the form of one or more pellets or mouldings. Where pellets are employed, the pellets may have a maximum dimension of 2 cm, preferably, 1 cm. In one embodiment, the pellets have a maximum dimension of from 0.1 to 0.5 cm, for example, 0.2 to 0.3 cm. Where mouldings are employed, each moulding preferably has a maximum dimension of 5 cm or less, more preferably, 4 cm or less, and even more preferably, 3 cm or less. In one embodiment, the mouldings have a maximum diameter of from 1 to 3 cm.

Where mouldings are employed, the mouldings may be extruded through a die. The die may have any cross-section, for example, a triangular, rectangular, hexagonal, square or circular cross-section (e.g. solid or hollow cylinders). The mouldings are preferably hollow. The walls of the hollow moulding may have a thickness of 1 to 5 mm, preferably, 1 to 3 mm, more preferably, 1 to 2 mm.

In a preferred embodiment, the product is in the form of a tube. The tube may be a moulded tube, such as an extrusion moulded tube. . The tube may have a maximum length of 5 cm or less, more preferably, 4 cm or less, and even more preferably, 3 cm or less. In one embodiment, the tube has a maximum length of 1 to 3 cm. The outside diameter of the tube is preferably less than 3 cm, more preferably, less than 2 cm, for example, less than 1.5 cm. The wall of the tube may be 1 to 5 mm thick, preferably, 1 to 3 mm thick, more preferably, 1 to 2 mm thick. In one embodiment, the tube has a length of approximately 10 mm, an outside diameter of 8.5 mm and a wall thickness of 1.5 mm. Before use, the product of the present invention may be sealed in a container that is impermeable to the vapours of the active air freshening, deodorising, pesticidal or insect repellent material. By sealing the product in this manner, the product may be maintained in a fresh (e.g. unused) state. One or more products may be sealed in such a container. For example, there may be 5 to 35, preferably, 10 to 30, more preferably, 20 to 25, products in the container.

In one embodiment, the product may be sealed in a container formed of glass or a polymeric material, such as polypropylene and/or polyethylene. The container may have an air-tight closure, such as a lid, which prevents the vapours of the active material from escaping before the product is put to use. In one embodiment, the container is a jar having an air-tight lid. The container may be used to contain one or more products, which may be withdrawn from the container when required (e.g. one at a time) . The lid may then be replaced to ensure that the remaining products are kept in a fresh (unused) state . In an alternative embodiment, the products may be wrapped in a wrapper formed, for example,, of foil laminate, aluminium foil or a polymeric material, such as polyethylene. When the product is ready for use, the wrapper may be removed. The products may be individually wrapped. The wrapped products may also be stored in a container, such as one of the containers described above.

A package comprising a compartment containing one or more unwrapped products of the present invention may also be provided. The package may contain from 1 to 10 products, for example, 2 to 6 products. In a preferred embodiment, one, two, three, four or five products are contained in the package. In a most preferred embodiment, one or two products are contained in the package. Each product is preferably in the form of an individual moulding, such as a cylinder or tube.

The unwrapped product (s) may be loosely contained in the package. Such a package is preferably permeable to the vapours of the active material, especially an air freshening, deodorising, pesticidal or insect repellent material. Thus, effective amounts of the composition, especially an air freshening, deodorising, pesticidal or insect repellent composition, may be released into the surrounding atmosphere without having to remove the product (s) from the package.

The package may be formed of any permeable material . Suitable materials include nonwoven materials, paper and/or plastic netting. The package may take the form of a sachet. The package is preferably at least partially transparent to allow the product (s) of the present invention to be viewed from the package exterior. For example, the package may be formed of a transparent material or a material (e.g. non-woven) having an open-weave structure. Alternatively or additionally, the package may be provided with a transparent window through which the product (s) are visible . The package may be resealable, for example, with a draw-string. The package may additionally or alternatively be provided with a handle or loop formed, for example, of string. Such a handle or loop allows the package to be suspended from, for example, a hook or knob.

One or more of such packages may be contained in a container that is impermeable to the vapours of the active air freshening, deodorising, pesticidal or insect repellent material. For example, 1 to 40 of such packages, preferably, 5 to 30, of such packages may be contained in the container. In a preferred embodiment, 10 to 25 packages are contained in the container. Preferably, the package (s) contained in the impermeable containers are permeable (e.g. formed of a permeable material) .

Suitable containers are impermeable to the vapours of the active material, such as the air freshening, deodorising, pesticidal or insect repellent material, described above. For example, the container may be formed of glass or a polymeric material, such as polypropylene and/or polyethylene. The container may have an air-tight closure, such as a lid, which prevents the vapours of the active material from escaping before the product is put to use. In one embodiment, the container is a jar having an air-tight lid. The package (s) may be removed from the container when desired. Typically, one package is removed at a time. The container may then be resealed (e.g. by replacing the lid) to keep the remaining packages in the container in their fresh (unused) state. As mentioned above, the vapours of the active component can emanate through the package, when the package is formed of a permeable material. Thus, the product does not need to be removed from the package when it is used.

In an alternative embodiment, the packages are wrapped in a wrapper formed, for example, of foil laminate, aluminium foil or a polymeric material, such as polyethylene. When the package is ready for use, the wrapper may be removed. The packages may be individually wrapped. The product of the present invention may be produced by impregnating the porous substrate with a liquid composition, for example an air-freshening, deodorising, pesticidal or insect repellent composition having a dye dissolved therein. The porous substrate may be contacted with the liquid composition, and allowed to absorb liquid composition, for example, until saturation. In one embodiment, the porous substrate is placed in a closed vessel, such as a tumble mixer, together with the liquid composition. The impregnation step may take from 5 minutes to 6 hours, preferably, 10 minutes to 3 hours, for example, from 30 minutes to 2 hours. The precise impregnation time may vary depending on a number of factors, such as the mean pore size of the substrate and/or the viscosity of the liquid composition.

The amount of liquid composition employed in the impregnation step may be just sufficient to fill the loading capacity of the substrate. As described above, the loading capacity of the substrate may be 60 to 80 %, preferably, 65 to 75 %. Alternatively, an excess of liquid may be employed. This excess may be removed, for example, by sieving or shaking.

In the impregnation step, the weight ratio of liquid composition to substrate may be 60 - 80:40 - 20, preferably, 65 - 75:35 - 25, for example, 70:30.

Impregnation of the porous substrate with the liquid composition preferably takes place at ambient temperature and pressure. Optionally, however, the liquid composition may be heated, for example, at 30 to 70°C.

In one embodiment, the dye is dissolved in the liquid composition before the liquid composition is contacted with the porous substrate. In an alternative embodiment, the dye is added to the liquid composition at substantially the same time as the porous substrate. In all cases, it is important that the dye is dissolved in the liquid composition. Heat may be employed to help the dye dissolve in the liquid composition. Once impregnated, the substrate is may be placed in a sealed container or wrapper, as described above. Prior to being sealed, it may be possible to place one or more of the impregnated substrates into a permeable package , such as those described above .

EXAMPLE 1

To a vessel containing 63.975 g of a perfume base (Lavandair 150.120D; origin - Firmenich SA, Geneva, Switzerland) and 16.0 g of the perfume base (Lavandair 150.120D) was added 0.025 g of dye (Iragon Violet SVI13; origin - Ciba Speciality Chemicals, Switzerland) with stirring.

After a homogenous solution was obtained, 34.28 g of solid microporous polypropylene (MP series, origin - membrana GmbH) was then added manually and mixed in a closed vessel with agitation for 1 hour.

At the end of the mixing step, the substrate had absorbed all the liquid composition; the dye and fragrance was evenly distributed throughout the substrate.

EXAMPLE 2

To a vessel containing 63.91 g of a perfume base (Solar Splash 150.555; origin - Firmenich SA, Geneva, Switzerland) and 16.0 g of the perfume base (Solar Splash 150.555), was added 0.09 g of dye (Sandoplast Yellow 3G; origin - Clariant UK Ltd, United Kingdom) After a homogenous solution was obtained, 34.28 g of solid microporous polypropylene (MP series, origin - Membrana GmbH) was then added manually and mixed in a closed vessel with agitation for 1 hour.

EXAMPLE 3 To a vessel containing 63.97 g of a perfume base_ (Summer Fruits 150.535; origin - Firmenich SA, Geneva, Switzerland) and 16.0 g of the perfume base (Summer Fruits 150.535), was added 0.03 g of dye (Fat Red 5B02; origin - Clariant UK Ltd, United Kingdom) .

At the end of the mixing step, the substrate had absorbed all the liquid composition; the dye and fragrance was evenly distributed throughout the substrate. EXAMPLE 4

To a vessel containing 63.98 g of a perfume base (Nile Blossom 438.910; origin - Firmenich SA, Geneva, Switzerland) and 16.0 g of the perfume base (Nile Blossom 438.910), was added 0.02 g of dye (Iragon Green; origin - Ciba Specialty Chemicals, Switzerland) with stirring. After a homogenous solution was obtained, 34.25 g of solid microporous polypropylene (MP series, origin - Membrana GmbH) was then added manually and mixed in a closed vessel with agitation for 1 hour.

At the end of the mixing step, the substrate had absorbed all the liquid composition; the dye and fragrance was evenly distributed throughout the substrate

EXAMPLE 5

To a vessel containing 63.97 of a perfume base (Summer Fruits 150.535; origin - Firmenich SA, Geneva, Switzerland) and 16. Og of the perfume base Summer Fruits 150.535) was added 0.03g of dye (Savinyl Fire Red GLSP; origin - Clariant UK Ltd, United Kingdom) with stirring.

After a homogenous solution was obtained 34.29 g of solid microporous polypropylene (MP series, origin -

Membrana Gmbh) was then added manually and mixed in a closed vessel with agitation for 1 hour.

Example 6 When the products of Examples 1 to 5 were exposed to the surroundings, perfume was released as a vapour. After 8 days of use, however, the dye had precipitated. An uneven distribution of solid dye particles became visible on the solid microporous substrate, indicating the end-of- life of the product. Beyond this point, the rate of air- freshener emanation from the product was no longer optimal.

Claims

1. A product comprising a solid, porous substrate and, impregnated therein, a liquid composition having a dye dissolved therein such that, after said product has been in use, the dye precipitates causing a colour change which can act as an end-of-life indication.

2. A product according to claim 1 wherein the substrate has a mean pore size of from 5 to 20 μm.

3. A product according to claim 1 or 2 wherein the substrate has a liquid loading capacity of from 60 to 80%.

4. A product according to any one of the preceding claims wherein the substrate comprises a polyolefin.

5. A product according to claim 4 wherein the polyolefin is polypropylene, high density polyethylene (HDPE) , linear low density polyethylene (LLDPE) or low density polyethylene (LDPE) .

6. A product according to any one of the preceding claims wherein the substrate is white.

7. A product according to any one of the preceding claims which is an air freshening, deodorising pesticidal or insect repellent product and the liquid composition is an air- freshening, deodorising, pesticidal or insect repellent composition.

8. A product according to claim 7 wherein the liquid air freshening, deodorising or pesticidal or insect repellent composition comprises at least 99 wt% of air freshening, deodorising pesticidal or insect repellent base.

9. A product according to claim 7 or 8 wherein the air freshening, deodorising, pesticidal or insect repellent composition is non-aqueous.

10. A product according to any one of the preceding claims wherein the dye is a metal-free solvent dye.

11. A product according to claim 9 wherein the dye is.C.I. Solvent Red 27, CI. Solvent Red 111, CI. Solvent Yellow 14, CI. Solvent Yellow 93, CI. Solvent Violet 13, CI.

Solvent Violet 37, C I Solvent Green 3, C I Solvent Green 28, C I Solvent Blue 104, Solvent Red 3 or a mixture thereof .

12. A product according to any one of the preceding claims wherein the liquid composition comprises less than 0.01 wt% dy .

13. A product according to any one of the preceding claims wherein the colour change is complete at a period of from 4 to 14 days from the start of use of the product.

1 . A product according to any one of the preceding claims which is in the form of a powder, granules, pellets or mouldings having a maximum dimension 'of 5 cm.

15. A product according to any one of the preceding claims which is in the form of a tube.

16. A package comprising a compartment having therein one or more unwrapped products as defined in any one of the preceding claims.

17. A package according to claim 16 which is resealable .

18. A package according to claim 16 or 17, which is at least partially transparent to allow the one or more unwrapped products to be visible from the exterior of the package .