WO2004087225A1

WO2004087225A1 - Air modifiying agent dispenser

Info

Publication number: WO2004087225A1
Application number: PCT/GB2004/001346
Authority: WO
Inventors: John Daniel Robert Pickering; John Stanley Payne
Original assignee: Robert Mcbride Limited
Priority date: 2003-04-04
Filing date: 2004-03-30
Publication date: 2004-10-14
Also published as: GB0307767D0; EP1663325A1

Abstract

The invention provides a dispenser (5) for dispensing an air modifying agent such as, for example, an air freshener, insecticide or odour neutralizer. The dispenser includes a container (6) in which is held an aqueous phase (7) and an immiscible fluid phase (8). An air modifying agent is entrained in the immiscible phase (8) and is carried to the exterior of the container through wick (10). The immiscible phase preferably includes a volatile silicone.

Description

AIR MODIFIYING AGENT DISPENSER

Field of the Invention

This invention relates to a dispenser and, in particular, to a device for dispensing an air modifying agent into the surrounding atmosphere.

Background to the Invention

Air modifying agents, typically comprising air fresheners, de-odourisers, insect repellants and the like, can be dispensed in many different ways. One way is to entrain the agent in a gel such that the agent evaporates when exposed to the atmosphere. The gel may be packed in a moulded container, which container is vented to atmosphere at point of use.

Examples of alternatives to entraining the active ingredient or agent in gel, comprise incorporating the agent in a liquid, the liquid being in contact with mat or wick. In use, the agent evaporates from the mat or wick.

When arriving at the design of an air treatment dispenser, considerations other than the mode of delivery, apply. As with any product targeted at consumers, aesthetics considerations also apply. Until now, any aesthetic distinction has been confined to variations in package configuration and colour.

It is an object of this invention to provide a form of dispenser for an air modifying agent which is at least a novel and useful variation to the forms of dispenser described above; or otherwise known heretofore. Summary of the Invention

Accordingly, in a first aspect, the invention provides a dispenser for an air modifying agent, said dispenser including:

a container;

a first, substantially aqueous, phase within said container;

a second phase within said container, said second phase being substantially immiscible in said first phase;

an air modifying agent within said container; and

a wick extending into said container and operable to convey said air modifying agent to an emanation point external to said container.

Preferably said air modifying agent is entrained within said second phase.

_f Preferably said wick is further operable to convey said second phase to said emanation point.

Preferably said second phase includes a volatile silicone material.

Preferably said volatile silicone material comprises volatile methylsiloxane.

Preferably said container is transparent.

Preferably said first and second phases are coloured differently. In a further aspect the invention provides a method of indicating the life of a dispenser of an air treatment agent, said method comprising entraining said air treatment in a volatile phase which is substantially immiscible in water; placing said volatile phase and a substantially aqueous phase in a container; providing a wick to draw said volatile phase from said container; and observing the depletion of said fluid phase.

In yet a further aspect the invention provides a liquid based air modifying dispenser characterized in that the liquid within said dispenser is provided in

at least two immiscible phases.

Preferably said dispenser is further characterized in that one phase is substantially aqueous whilst the other phase includes a volatile silicone material.

Many variations in the way the invention may be performed will present themselves to those skilled in the art upon reading the following description. The description which follows should not be regarded as limiting but rather, as an illustration only of one mode of performing the invention. Where possible, a description of any element or component should be taken as including any or all equivalents thereof whether or not specifically mentioned. The scope of the invention should be determined solely by the appended claims.

Brief Description of the Drawings

One form of dispenser embodying the various aspects of the invention will now be described with reference to the accompanying drawing in which: Figure 1 : shows an elevational view of a dispenser according to the invention.

Detailed Description of Working Embodiment

Referring to Figure 1, the invention provides a dispenser 5 for dispensing an air modifying agent. In the form shown the dispenser includes a container 6 in which is contained a substantially aqueous phase 7 and an immiscible phase 8. The immiscible phase is also preferably substantially liquid in form. The immiscible phase thus floats on the aqueous phase.

Entrained within the liquid, and preferably within the immiscible phase 8, is an air modifying agent. Typically this air modifying agent will be a fragrance but it could also comprise, or include, insect repellants, anti-oxidising agents, de-odourising agents etc. The precise make-up of the air modifying agent does not form part of the invention.

In the embodiment described herein, the aqueous phase 7 is substantially water however salts and/or other additives, soluble in water, may be added to tailor the properties of the aqueous phase for specific applications. A small amount of preservative is generally added to this phase along with one or more dyes to give the desired colour.

The fluid or immiscible phase largely comprises a solvent for the air modifying agent. This must be compatible with the carrier in which the air modifying agent is provided. Typically fragrances are provided in an oil based carrier however certain oil based solvents can present particular labeling requirements. Surprisingly we have found that such fragrances can be dissolved in liquid volatile silicones, and used effectively in a wick-based emanation system. We have found a class of volatile methylsiloxane fluids to be particularly suitable. These fluids have a low order of human toxicity and, surprisingly, can be drawn through wicks typically encountered in air freshening applications, without demonstrating the expected clogging effects.

Using a fragrance system carried in an isobar base, we have found that satisfactory results can be achieved by formulating the immiscible phase to include a total isopar content of around 0 to 10% w/w, a fragrance content of about 5 to 30% w/w and a volatile silicone content of around 50 to 75% w/w. Dyes can also be added to give the required colour, the content of such dyes being unlikely to exceed 0.01 % w/w.

The ratio of aqueous phase to immiscible phase can be varied at will.

The fact that the immiscible phase 8 floats on the aqueous phase 7 leads to the provision of a liquid-based air treatment dispenser having a particularly pleasing appearance. This is enhanced still further if the container 6 is substantially transparent, and may be further enhanced by colouring the two phases differently.

In the form shown, a wick 10 is provided to convey the air modifying agent from the interior to the exterior of the container 6. As shown, the wick 10 comprises a rod of polyester fibre with a non- woven wrap provided about the cylindrical outer surface. Some experimentation may have to be undertaken to select a wick pore size which provides the desired capillary action for the given phase constituents.

As can be seen, the wick is displaced down so that the bottom edge thereof substantially contacts the inner base of the container 6. Thus both phases can be drawn up by the wick. The wick need not, necessarily, be in the form of a rod as shown but may be of any compatible form which can draw the liquid from the container under a capillary action, and allow the air modifying agent to evaporate off, once outside the container.

In use, the immiscible phase containing the air modifying agent is first drawn through the wick. Whilst no detailed study has been undertaken to understand why this is so, it is believed that factors such as the lower vapour pressures of the fragrance and oil-based solvents, and surface tension effects, are the cause. At the emanation point, defined substantially by the upper end 12 of the wick, the immiscible phase evaporates off and passes into the surrounding atmosphere.

As the immiscible phase continues to evaporate off from the wick, the immiscible layer 8 within the container, visibly depletes. Thus the consumer has a clear visual gauge of the life of the dispenser. That is not to say that the efficacy of the dispenser ceases as soon as layer 8 disappears. In reality, residual air modifying agent continues to be held in the wick and the device can therefore continue to operate until this residual agent has been displaced from the wick by the aqueous phase moving up the wick under capillary action.

Example

A two phase, two layer air freshening dispenser according to the invention was made up as follows:

Immiscible Phase

% w/w Isopar K 11.43 Fragrance (F555707 ex Quest) 20

Volatile silicone (Dow Corning DC345) 68.5468

Dye Blue 0.0039

Dye Red 0.0013

Aqueous Phase

% w/w Water 99.89956

Parmetol DF35 0.1

Dye Red 0.0032 Dye Violet 0.0012

The two phases were combined in a transparent glass container, 35g of the immiscible phase being combined with 37g of the aqueous phase. As expected, the immiscible phase floats on top of the aqueous phase.

A wick of polyester fibre, having a non- woven wrap, was inserted through the open neck of the container and displaced down into loose contact with the base of the container. The wick had a weight of 4.29 mg for a length of 110mm and a diameter of 16mm.

The resulting air freshener performed extremely well in testing, giving good fragrance release. The immiscible phase disappeared after 30 days when tested at a constant temperature of 21 °C, but the dispenser continued to release fragrance for a further period of 15 days as residual fragrance retained with the wick was displaced into the atmosphere by the aqueous phase being drawn up the wick.

It will thus be appreciated that the present invention, at least in the case of the working embodiment described above, provides a simple yet effective form of dispenser for an air modifying agent which includes two liquid phases. These two phases provide a pleasing aesthetic effect whilst also giving a visual indication of the remaining life of the product.

Claims

1. A dispenser for an air modifying agent, said dispenser including:

a container;

an aqueous phase within said container;

a fluid phase within said container, said fluid phase being substantially immiscible in said aqueous phase;

an air modifying agent within said container; and

2. A dispenser as claimed in claim 1 wherein said air modifying agent is entrained within said fluid phase.

3. A dispenser as claimed in claim 1 or claim 2 wherein said wick is further operable to convey said fluid phase to said emanation point.

4. A dispenser as claimed in any one of claims 1 to 3 wherein said fluid phase includes a volatile silicone material.

5. A dispenser as claimed in claim 4 wherein said volatile silicone material comprises volatile methylsiloxane.

6. A dispenser as claimed in any one of the preceding claims wherein said container is transparent.

7. A dispenser as claimed in any one of the preceding claims wherein said aqueous and fluid phases are coloured differently.

8. A method of indicating the life of a dispenser of an air treatment agent, said method comprising entraining said air treatment in a volatile fluid phase which is substantially immiscible in water; placing said fluid phase and an aqueous phase in a container; providing a wick to draw said fluid phase from said container; and observing the depletion of said fluid phase.

9. A liquid based air modifying dispenser characterized in that the liquid within said dispenser is provided in at least two immiscible phases.

10. A dispenser as claimed in claim 9 further characterized in that one phase is substantially aqueous whilst the other phase includes a volatile silicone material.