초록

Air treatment apparatus comprises an electric heating element (5) and a refill pack containing wax or paraffin granules (2) incorporating a fragrance or other active substance eg. insect repellent. In another embodiment heat is supplied by a exothermic reaction mixture.

대표청구항 ▼

The invention claimed is: 1. Air treatment apparatus for volatilising a fragrance or active substance, the apparatus comprising a receptacle containing water in contact with particulate wax or paraffin, said particulate wax or paraffin having said fragrance or other active substance dispersed withi

The invention claimed is: 1. Air treatment apparatus for volatilising a fragrance or active substance, the apparatus comprising a receptacle containing water in contact with particulate wax or paraffin, said particulate wax or paraffin having said fragrance or other active substance dispersed within particles of the wax or paraffin, and controlled heating means for heating said particulate wax or paraffin to release said fragrance or other active substance from within the wax or paraffin and into the atmosphere. 2. Apparatus according to claim 1, wherein said controlled heating means is an electric heating element. 3. Apparatus according to claim 2, wherein said electric heating element has means for self-limiting the heating of said particulate wax or paraffin. 4. Apparatus according to claim 1, wherein said controlled heating means comprises an exothermic reaction composition. 5. Apparatus according to claim 4, further comprising a closed container of water and means for bringing the water from said container into contact with said reaction composition. 6. Apparatus according to claim 5, wherein said container of water has a frangible portion for releasing the water into said reaction composition. 7. Apparatus according to claim 4, wherein said exothermic reaction composition is activated by contact with water. 8. Apparatus according to claim 4, wherein said exothermic reaction mixture is in contact with said particulate wax or paraffin and is arranged in use to volatilise said fragrance or other active substance therefrom. 9. Apparatus according to claim 4, wherein the exothermic reaction composition comprises calcium oxide. 10. Apparatus according to claim 4, wherein said exothermic reaction composition is arranged in use to generate steam which volatilises said fragrance or other active substance. 11. Apparatus according to claim 1, wherein said controlled heating means is arranged to melt said particulate wax or paraffin. 12. Apparatus according to claim 1, wherein said particulate wax or paraffin is in the form of granules, the granules being sufficiently loosely packed to allow release of fragrance or other active substance from the interstices of the packed granules. 13. Apparatus according to claim 11, wherein the mean diameter of said granules is in the range 2 to 8 mm. 14. Apparatus according to claim 1, wherein said fragrance and/or other active substance comprises two or more components of different volatility which in use are preferentially released at different stages as the particulate wax or paraffin is heated. 15. Apparatus according to claim 1, wherein said wax or paraffin comprises two or more components of different melting point whereby the wax or paraffin is arranged in use to melt progressively on heating. 16. Apparatus according to claim 1, wherein said particulate wax or paraffin comprises a long-chain fatty alcohol or a mixture of long-chain fatty alcohols and fatty acids and optionally contains a fatty alcohol ethoxylate and/or polyethylene glycol. 17. Apparatus as claimed in claim 4, wherein water-activatable heat generating chemical(s) are mixed with granules of wax or paraffin having said fragrance or other active substance dispersed therein. 18. Apparatus as claimed in claim 1, wherein said heating is effected by indirect means. 19. Apparatus as claimed in claim 1, wherein said fragrance or other active substance or substances is dispersed in heat transfer liquid selected from water, glycols, alcohols with boiling points above 100° C., mineral oils, silicone oils and mixtures thereof. 20. Apparatus as claimed in claim 18, wherein the heat-generating composition is contained in a replaceable unit. 21. Apparatus according to claim 1, wherein water is fed into contact with said heat-generating composition through a sintered filter. 22. Apparatus according to claim 1, wherein means are provided for raising or lowering the heat generating composition into and from water. 23. An air treatment apparatus for volatilizing a fragrance or other active substance comprising: (i) a particulate wax or paraffin having at least one fragrance or other active substance dispersed within particles of said wax or paraffin such that the particulate wax or paraffin retains the fragrance or other active substance within particles of the wax or paraffin at an ambient temperature below a melting point of the wax or paraffin and releases substantially all of the fragrance or other active substance when the particles are heated to the melting point of the wax or paraffin; (ii) a receptacle for containing the particulate wax or paraffin having the fragrance or other active substance dispersed therein; and (iii) means for controlled heating of the particulate wax or paraffin within the receptacle by reaction of a chemical substance and water that generates steam which volatilizes the fragrance or other active substance such that the fragrance or other active substance is gradually released by diffusion from the particulate wax or paraffin. 24. The apparatus according to claim 23, wherein the at least one fragrance or other active substance is dispersed in the paraffin by a process comprising (a) loading the paraffin with the at least one fragrance or other active substance before the paraffin is reduced to particulate form and (b) then reducing the paraffin to particulate form.