WO2008152353A1

WO2008152353A1 - Improvements in or relating to devices

Info

Publication number: WO2008152353A1
Application number: PCT/GB2008/001809
Authority: WO
Inventors: Neil Atkin; Alistaire Robin Dyson; Loic Marouse; Malcolm Tom Mckechnie
Original assignee: Reckitt Benckiser (Uk) Limited
Priority date: 2007-06-14
Filing date: 2008-05-29
Publication date: 2008-12-18
Also published as: GB2450134A; GB0711469D0

Abstract

A device for emanating an active agent to the atmosphere comprising an active agent, a first compartment holding a first liquid, a second compartment holding a second liquid, and a wicking member that draws the first liquid or the second liquid from its compartment and into contact with the other liquid, whereby the liquids mix and react to generate heat and thereby volatilise the active agent. The first liquid may comprise a reducing agent and the second liquid an oxidising agent, wherein the reducing agent comprises a thiosulfate or bisulfate and the oxidising agent comprises peroxide. Further, the one of the liquid comprises a catalyst for the reaction between said liquids.

Description

Improvements in or relating to Devices

The present invention relates to a device that enables the emanation of a volatile active agent, such as a deodorising, sanitising, air freshening, aromatherapy, therapeutic, pesticidal or insect repellent composition, into the surrounding atmosphere without requiring separate heating and/or electrical means.

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

For example, air-freshening devices or deodorisers are currently used in many households to mask bad odours, or to impart fragrances to the ambient air. Various types of devices are known for the diffusion of volatile active agents into the surroundings.

Devices for providing and dispensing volatile active agents are well-known in the art. Such devices can include room fresheners or fragrancing articles, vaporizers for humidification or dispensing and dispersal of therapeutic vapours, incense sticks, fragrancing or insect-repelling candles. Such devices generally involve utilization of some source of heat which promotes the volatilization of the active agents to be dispensed and, of course, some source of the volatile or volatilizable materials themselves. Some fragrancing devices, such as candles and incense sticks, involve use of an open flame or an active combustion reaction to provide the source of heat which promotes volatilization. Besides the obvious drawbacks of the hazards of using such types of heat sources, arrangements which involve flames or combustion are not especially portable and cannot be used, for example, in automobiles or around flammable materials.

Other types of dispensing devices for volatiles use electrical energy as a heat source, for example plug-in room air-fresheners. The amount of electrical energy required to operate devices of this type renders such devices relatively non-portable .

PCT/GB2006/003605 describes a device for emanating an active agent, such as a fragrance, to the atmosphere. The device comprises a first container holding a first liquid and a second container holding a second liquid. An outlet from each of the containers drips the liquids onto a collector where the liquids mix and react to generate heat that volatilises the active agent.

There remains a need to provide a device for emanating an active agent that is safe and convenient to use.

According to the present invention, there is provided a device for emanating an active agent to the atmosphere comprising an active agent, a first compartment holding a first liquid, a second compartment holding a second liquid, and a wicking member that draws the first liquid or the second liquid from its compartment and into contact with the other liquid, whereby the liquids mix and react to generate heat and thereby volatilise the active agent.

Preferably, the wicking member draws both the first liquid and the second liquid from their respective compartments into contact with one another. In one embodiment, a part of the wicking member contacts the first liquid held in the first compartment, and a part of the wicking member contacts the second liquid held in the second compartment. The first liquid and the second liquid may travel along the wicking member, for example, by capillary action. When the two liquids meet, the liquids mix and react to generate the heat for volatilising the active agent. Accordingly, the wicking member may provide a region or platform for the reaction to occur. In one embodiment, the wicking member comprises a portion having a region of greater surface area over which the reaction between the first liquid and second liquid can occur.

In an embodiment, one end of the wicking member may extend into the first compartment, while the opposite end of the wicking member may extend into the second compartment. In another embodiment, the wicking member comprises a first wick portion that contacts the first liquid held in the first compartment and a second wick portion contacts the second liquid in the second compartment. The first and second wick portions are preferably movable from a first position where they are not in contact with one another to a second position where they are in contact with one another, whereby the liquids mix and react to generate heat and thereby volatilise the active agent. In this embodiment, - A -

the heat generated may be reduced when desired, for example, by separating the wick portions.

The wicking member may be positioned relative to the first and second compartments, such that the liquids can travel along the wicking member under gravity.

The wicking member may be formed of any suitable material. The skilled person will understand that this may be any suitable cellulose, plastics or ceramic material.

Examples include fibres, paper and/or fabrics, such as woven and non-woven fabrics or porous polymers. In one embodiment, the wicking material is formed from polyester fibre that is optionally wrapped, for example, with paper or other porous wrapping material. An example of a suitable porous wrapping material is formed from PET (e.g. non-woven PET) .

In a further embodiment, the wicking member comprises at least a first portion which is in the first compartment and at least in partial contact with the first liquid so as to absorb said first liquid, and wherein the first portion is moveable from a first position in which said portion is in the first compartment to a second position in which the first liquid absorbed by said portion is brought into contact with the second liquid.

Preferably, the wicking member further comprises a second portion that is at least partially located in the second compartment and at least in partial contact with the second liquid so as to absorb said second liquid, wherein the second portion is moveable from a first position in which said portion is in the second compartment to a second position in which said second portion is brought into contact with said first portion.

In a particularly preferred embodiment, the first and second wick portions comprise lengths of a suitable material such that when the wick portions are moved from the first position to the second position the material is drawn from the first and/or second compartment in a continuous manner. It will be apparent that the material forming the wick portions can be held within the device in any suitable manner, for example, it may be in the form of a spooled roll, or may be folded in a concertinaed manner. The device may be provided with means for moving the first and/or second wick portions. For example, the device may be provided with a winding mechanism for moving the wick portions from the first position to the second position.

Preferably, the wicking member allows removal of spent material from the second position. This can be by any suitable method known in the art, for example, the material forming the wicking member may be perforated to allow easy removal by tearing.

The first compartment and second compartment may be formed as two separate containers. The containers may be formed of any impermeable material, such as glass or a plastics material. Examples of suitable plastics include polyethylene and polypropylene. Alternatively, the device may comprise a housing that is divided into a first compartment and a second compartment. The housing may be formed of any impermeable material, such as glass or a plastics material. Examples of suitable plastics include polyethylene and polypropylene.

In a preferred embodiment, the first liquid includes a reducing agent, whilst the second liquid includes an oxidising agent.

Suitable reducing agents include sulfides, sulfites, sulfates, oxazolidines, bisulfates, ascorbic acid, oxalic acid, iodides, ferrous ammonium sulphate and thiosulfates . Preferably, a thiosulfate is employed. Alkali metal sulfides, sulfites, sulfates, oxazolidines, bisulfates, ascorbic acid, oxalic acid, iodides, ferrous ammonium sulphate and thiosulfates are particularly preferred. Examples of suitable alkali metals include Li, Na and K.

Most preferably, an alkali metal thiosulfate, such as sodium thiosulfate is employed.

The preferred amount of reducing agent in the first liquid is preferably such that there is sufficient reducing agent present to reduce all, substantially all, or at least most, of the oxidising agent present in the second liquid, whilst providing the sufficient generation of heat to volatilise the active agent. Most preferably the concentration of reducing agent is the same, or substantially the same, as the amount of oxidising agent present in the second liquid. Even more preferably, the reducing agent is present in the first liquid at a concentration of from 1 to 40 weight % (where weight percent of reducing agent is the concentration of reducing agent in the first liquid, i.e. the weight percent of the reducing agent in the first liquid) , preferably from 2 to 15 weight %, more preferably from 4 to 10 weight% and even more preferably in an amount of about 5 weight %

In a preferred embodiment the second liquid comprises an oxidising agent. Suitable oxidising agents include both peroxygen-based oxidising agents and hypohalite-based oxidising agents. Examples include hydrogen peroxide, hypochlorous acid, hypochlorites, hypocodites, and percarbonates . Also included are alkali metal chlorites, hypochlorites, for example sodium chlorite and sodium hypochlorite. Hydrogen peroxide precursors such as peroxygen bleaching agents can also be used, for example alkali metal perborates and percarbonates, for example, sodium percarbonate and sodium perborate. However, particularly preferred as the oxidising agent are peroxides, most particularly hydrogen peroxide. Thus, in a particularly preferred embodiment of the invention, the second liquid comprises hydrogen peroxide.

Hydrogen peroxide is a chemical that has particular user compliance considerations. As it is a relatively strong oxidising agent, direct contact between concentrated hydrogen peroxide solutions and the user should preferably be avoided. In the present invention, oxidising agent combines with the reducing agent to generate heat. However, the presence of relatively high concentration oxidising agents even as part of one of the liquids could prove dangerous. For instance, if the oxidising and reducing agents are not completely mixed, there exists the possibility of non-reduced oxidising agents being touched by the user. Moreover, should the mixing or combining mechanism of the two components malfunction in any way, it is again possible for non-reduced oxidising agent to be present. Hence, it is preferable for the concentration of oxidising agent to be as low as possible, whilst still retaining the ability to react with the reducing agent and thus generate heat.

Preferably, therefore, the oxidising agent is present in the second liquid at a concentration of from 1 to 20 weight % (where weight percent of oxidising agent is the concentration of oxidising agent in the second liquid, i.e. the weight percent of the oxidising agent in the second liquid), preferably 2 to 15 weight %, more preferably from 4 to 10 weight % and even more preferably in an amount of about 7 weight %.

In a preferred embodiment when a sufficient amount of reducing agent, for example sodium thiosulfate, and oxidising agent, for example, hydrogen peroxide, are mixed together, a Redox reaction occurs. Thus the hydrogen peroxide brings about the oxidation of sodium thiosulfate at the same time as the sodium thiosulfate brings about the reduction of the hydrogen peroxide. This Redox reaction results in the generation of heat. Sufficient heat is produced to enable the active agent to volatilise.

A person skilled in the art will understand that the levels of reducing and oxidising agents can be tailored to deliver quicker heat, longer lasting heat, more heat, less heat and variations along that theme by altering the amount of reducing and/or oxidising agent present in the liquids. Suitably, in use, appropriate relative amounts of reducing and oxidising agents are mixed such that they mix in the amounts required to generate heat and thereby volatise the active agent. In preferred embodiments, the agents are preferably mixed in a ratio between 10:1 and 1:10 by weight, more preferably between 5:1 and 1:5 by weight, most preferably between 2:1 and 1:2 by weight, for example, approximately equal amounts.

A person skilled in the art will understand that any mixture of two compounds that can produce an exothermic reaction, i.e. produce heat, can be used in the present invention.

The device includes an active agent. This active agent is volatilised by the heat generated by the reaction between the first and second liquids and thus emanated from the device into the atmosphere. The heat generated by the reaction between the first and second liquids can be used to initiate the release of active agent into the atmosphere, or to boost the release of active agent into the atmosphere.

The active agent may be present in the first liquid and/or in the second liquid. Preferably, the active agent is present in the liquid that contains the reducing agent. Thus, in a preferred embodiment, the active agent is contained in the first liquid. In an alternative embodiment, however, the active agent may be present in other parts of the device, for example, on the wicking member. The active agent can be an air-freshening, deodorising, pesticidal and/or insect repellent composition. Preferably, the active agent is an air-freshening composition.

When an air freshening composition is employed, the active agent includes or is 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 specialised 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.

A perfume base may also be included in any deodorising, aromatherapy, therapeutic, pesticidal or insect repellent composition employed. For example, insect repellent fragrant materials may be used, such as citronella oil, thus providing a device and method for repelling insects.

Where the active agent is present in the first liquid or the second liquid, the active agent is present in an amount of from 0.01 to 25 weight %, preferably from 1 to 22 weight %, more preferably from 4 to 20 weight %, yet more preferably from 5 to 15 weight% and even more preferably in an amount of 8 to 10 weight % of the first liquid or the second liquid.

A catalyst that increases the rate of the reaction (e.g. redox reaction) between the two liquids can also be present. The catalyst can be present in the first liquid and/or in the second liquid. In a preferred embodiment the catalyst is present in the first liquid, for example, together with the reducing agent. Preferably, the catalyst comprises a metal-containing ion, more preferably a transition metal-containing ion, for example containing an ion of manganese, copper, molybdenum, or tungsten, together with an alkali or alkaline earth metal, such as sodium. More preferably, the catalyst is a tungstate compound, although other ions comprising a transition metal ion and oxygen, e.g. manganese, copper, or molybdenum with oxygen, can be used. Yet more preferably, the catalyst is an alkali metal tungstate (e.g. contains the WO₄ ^2" ion), most preferably sodium tungstate (e.g. Na₂WO₄), suitably in the form sodium tungstate dehydrate (e.g. Na₂WO₄.2H₂O) .

Preferably, the catalyst is present in an amount sufficient to catalyse the reaction between the two liquids. More preferably, the catalyst is present to a maximum of 2 weight % , even more preferably to a maximum of 1 weight %, yet more preferably in the range 0.01 to 0.5 weight %, even more preferably in the range 0.1 to 0.5 weight %, for example at about 0.1 weight % or at about 0.5 weight % of the first or second liquid, preferably the first liquid.

When the oxidising agent is a hydrogen peroxide precursor, such as peroxygen bleaching agents, for example an alkali metal perborate or percarbonate, a bleach activator such as tetraacetyl ethylene diamine (TAED) or nonanoyloxybenzene sulfonate (NOBS) or mixtures thereof are preferably present. The bleach activator will assist in accelerating the break down of the bleach activator to the corresponding peroxy acid, for example, alkali metal perborate or percarbonate to hydrogen peroxide. The bleach activator may be present in the first liguid or the second liquid, preferably the first liquid.

The bleach activator may be present to a maximum of 2 weight % , even more preferably to a maximum of 1 weight %, yet more preferably in the range 0.01 to 0.5 weight %, even more preferably in the range 0.1 to 0.5 weight of the first or second liquid.

The first liquid may also further comprise a basic buffering system, such as amino-alcohol compounds, for example, ethanolamine or 2-aminoethanol (MEA) , in an amount of from 1 to 15%, preferably from 2 to 10 weight %.

The first and/or second liquid may also further comprise an oil solubilizer, such as a surfactant. The surfactant may be used to emulsify any oily components of the liquids. For example, where an oily active agent is employed, a surfactant may be used to emulsify the oily active agent. The surfactant may also be included to alter the viscosity and surface tension properties of the liquid.

Suitable surfactants include amphoteric, non-ionic, anionic and cationic surfactants. Preferably, amphoteric and/or non-ionic surfactants are employed. Suitable surfactant include amine oxide surfactants, such as those sold under the Ammonyx trade mark. Other examples include alkoxylated (e.g. ethoxylated) alcohols, such as those sold under the Plurafac, Empilan and Lutensol trade marks. The non-ionic surfactant may contain polyethylene oxide groups, such as Triton X-IOO.

The surfactant may be present in an amount of 1 to 40 weight %, preferably 5 to 20 weight %.

The first liquid and the second liquid preferably include water, such as deionised water. Water may be present in an amount of 30 to 98 weight %, preferably 50 to 95 weight %. In the first liquid, water is preferably present in an amount of 40 to 95 weight %, preferably 50 to 80 weight %. In the second liquid, water may be present in an amount of 50 to 98 weight %, preferably, 85 to 95 weight %. The device preferably includes 0.1 to 500 ml, preferably 0.5 to 100 ml, more preferably 1 to 20 ml of the first liquid. The device preferably includes 0.1 to 500 ml, preferably 0.5 to 100 ml, more preferably 1 to 20 ml of the second liquid. The volume of first liquid may be the same or different from the volume of second liquid in the device. Preferably, the volume ratio of the first liquid to the second liquid is 1:4 to 4:1, preferably, 1:2 to 2:1, for example 1 : 1

The density of the first liquid is the same or different to the density of the second liquid. The first liquid preferably has a density of 0.2 to 5 g/cm³, more preferably 0.5 to 2^'g/cm³' The second liquid preferably has a density of 0.2 to 5 g/cm³ , more preferably 0.2 to 5 g/cm³g/cm³. The first liquid or the second liquid may contain a thickener to alter the viscosity of the liquid as desired. Suitable thickeners cellulose thickeners, such as hydroxyethylcellulose . The thickener may be present in an amount of 0 to 20 weight %, preferably 0.1 to 5 weight %.

The viscosity of the first liquid should be 1 to 3OcP, preferably 5 to 20 cP when measured with a Brookfield viscometer (e.g. model DV-II using LV63 spindle) at 50 rpm at a temperature of 23 degrees C. The viscosity of the second liquid should be 1 to 3OcP, preferably 5 to 20 cP when measured with a Brookfield viscometer (e.g. model DV-II using LV63 spindle) at 50 rpm at a temperature of 23 degrees C. The first liquid may have the same or different viscosity from the second liquid. The viscosities of the first liquid and second liquid may be varied to alter the rates at which they travel along the wicking member.

The heat generated by the reaction between the first liquid and the second liquid may be sufficient to raise the temperature of the liquids by 1 to 70 degrees C, preferably 3 to 40 degrees C, more preferably 5 to 20 degrees C above ambient temperature.

Embodiments of the device of the present invention will now be described with reference to the figures in which: -

Figure 1, is a schematic view of a device according to an embodiment of the invention.

Figure 2, is an end view of a device according to a further embodiment of the invention. Referring to Figure 1, this drawing depicts a device 10 for emanating a fragrance into the atmosphere. The device 10 comprises a first compartment 12 holding a first liquid 14 and a second compartment 16 holding a second liquid 18. The device 10 also includes a wicking member 20. The first liquid 14 contains the fragrance. The compartments 12 and 16 are sealed by covers 22.

The wicking member 20 draws the first liquid 14 and the second liquid 18 from their respect compartments 12,16 and into contact one another. The liquids mix and react on the wicking member 20 to generate heat and thereby volatilise the fragrance.

Referring to Figure 2, this depicts a device 100 for emanating a fragrance into the atmosphere. The device 100 comprises a housing 102 having a first compartment 104, a second compartment 106 and a sealing lid 108. The device 100 further comprises a first wicking member in the form of a first absorbent sheet material 110 located in the first compartment 104 and a second wicking member in the form of a second absorbent sheet material 112 located in the second compartment 106. The first and second absorbent sheet materials 110, 112 are wound around first and second spools 114, 116 respectively. The first and second absorbent sheet materials 110, 112 further have first and second liquids respectively absorbed therein. The first liquid contains the fragrance.

A first end of the first absorbent sheet material 110 passes out of the first compartment 104 via opening 118, located in the lower surface of lid 108 and into a third compartment 120 located within lid 108. The absorbent sheet material 110 is retained in place by retention rollers 122. Similarly, a first end of the second absorbent sheet material 112, passes out of the second compartment 106 via opening 124 located in the lower surface of lid 108 and into the third compartment 120 located within lid 108 where it is retained in place by retention rollers 126. The retention rollers 122, 126 do not exert sufficient pressure on the absorbent sheet material 110, 112 to prevent liquid from wicking past the rollers. The first and second absorbent sheet materials 110 and 112 pass through the third compartment 120 to opening 128 where they are brought into contact with each other and the external atmosphere.

The absorbent sheet materials 110, 112 have the first and second liquids absorbed therein so that when they are brought into contact with each other the liquids mix. Mixing of the liquids causes them to react to generate heat and thereby volatilise the fragrance.

In use, the absorbent sheet materials 110,112 are drawn from the first and second compartments 104,106 and brought into contact through a mechanical pulling action. Alternatively the device may be provided with a winding mechanism that automatically moves the sheet materials into contact (not shown) . When it is desirable to volatilise the active agent, the user grasps the absorbent sheet materials and draws these from the device and into contact. Once the active agent present on the exposed absorbent sheet materials 110,112 is spent, this may be torn away and discarded. When it is desired to release more active agent, further sheet materials may be drawn from the compartments 104,106.

Example

The following first liquid was prepared and placed into the first compartment 14 of the device 10 of Figure 1:

8 weight % sodium thiosulphate 0.13 weight % sodium tungstate 8 weight % ethanolamine 18 weight % Ammonyx 12 weight % Fragrance 53.87 weight % Deionised water

The following second liquid was prepared and placed into the second compartment 16 of the device 10 of Figure 1:

8 weight % hydrogen peroxide 92 weight % deionised water

Claims

1. A device for emanating an active agent to the atmosphere comprising an active agent, a first compartment holding a first liquid, a second compartment holding a second liquid, and a wicking member that draws the first liquid or the second liquid from its compartment and into contact with the other liquid, whereby the liquids mix and react to generate heat and thereby volatilise the active agent .

2. A device as claimed in claim 1, wherein the wicking member draws both the first liquid and the second liquid from their respective compartments into contact with one another.

3. A device as claimed in claim 1 or 2, wherein the wicking member is formed of cellulose, plastics or ceramic material.

4. A device as claimed in any one of the preceding claims, wherein the wicking member comprises a portion having a region of greater surface area over which the reaction between the first liquid and second liquid occurs.

5. A device as claimed in any one of the preceding claims, wherein the wicking member comprises a first wick portion that contacts the first liquid held in the first compartment and a second wick portion contacts the second liquid in the second compartment, said first and second wick portions being movable from a first position where they are not in contact with one another to a second position where they are in contact with one another, whereby the liquids mix and react to generate heat and thereby volatilise the active agent .

6. A device as claimed in any one of the preceding claims, wherein the first liquid and the second liquid have substantially the same viscosities.

7. A device claimed in any one of the preceding claims, wherein the first liquid and/or the second liquid comprises the active agent.

8. A device as claimed in any one of claims 1 to 6, wherein the active agent is provided on the wicking member.

9. A device as claimed in any one of the preceding claims, wherein the first liquid comprises a reducing agent and the second liquid comprises an oxidising agent.

10. A device as claimed in claim 9, wherein the reducing agent comprises a thiosulfate or bisulfate.

11. A device as claimed in claim 9 or 10, wherein the oxidising agent comprises a peroxide.

12. A device as claimed in any one of the preceding claims, wherein the first liquid and/or second liquid comprises a catalyst for the reaction between said liquids.

13. A device as claimed in any one of claims 1 to 11, wherein a catalyst for the reaction between said liquids is provided on the wicking member.

14. A device as claimed in any one of the preceding claims wherein the active agent is a deodorising, sanitising, air freshening, aromatherapy, therapeutic, pesticidal or insect repellent composition.

15. A device as claimed in any one of the preceding claims, which is an air-freshening device, wherein the active agent comprises a fragrance.

16. A device as herein described with reference to the accompanying drawing.