Method and device to evaporate active ingredients from a liquid solution

Abstract

The present invention relates to a method and a device to evaporate low volatility active substances or ingredients from a liquid solution contained in a reservoir ( 2 ). The device comprises at least one liquid retaining support and dispensing means ( 14 ) arranged in a casing ( 1 ) at a distance and in a suitable position for dispensing doses of said liquid solution on said support by means of a push-button ( 6 ). The device further has a timer adapted to allow the operation of said dispensing means in selected time periods, said time periods being greater than the time necessary for evaporating most of the solvent and active ingredient from the support.

1 . A method to evaporate active ingredients from a liquid solution, in which said liquid solution comprises a solvent and at least one type of active ingredient, the method comprising:
 dispensing in controlled time periods doses of said liquid solution on a liquid retaining support,   wherein the solvent is evaporated from said support such that only the active ingredient remains on the support, and wherein the active ingredient is evaporated from the support after most of the solvent has evaporated.   
   
   
       2 . A method according to  claim 1 , wherein the time periods between doses are controlled such that a dose of the liquid solution is dispensed on said support at an instant in time after the evaporation of most of the active ingredient of the previous dose from the support. 
   
   
       3 . A method according to  claim 1 , wherein the time period between two consecutive doses is greater than the time necessary to evaporate the solvent and the active ingredient from the support. 
   
   
       4 . A method according to  claim 3 , wherein the time period between two consecutive doses is substantially similar to the time necessary to evaporate the solvent and the active ingredient from the support. 
   
   
       5 . A method according to  claim 1 , wherein the time periods between doses are controlled by means of an electronic timer which is associated to electromechanical means to allow dispensing a dose of liquid solution after the established time period between doses. 
   
   
       6 . A method according to  claim 1 , wherein a dose of liquid solution is dispensed by impulse activation by the user. 
   
   
       7 . A method according to  claim 1 , wherein a dose of liquid solution is dispensed automatically in a pre-established time interval. 
   
   
       8 . A method according to  claim 1 , wherein the solvent and/or the active ingredient are heated during their evaporation, at a temperature less than 100° C. 
   
   
       9 . A method according to  claim 1 , wherein the solvent and the active ingredient are evaporated at room temperature 
   
   
       10 . A method according to  claim 1 , wherein an air stream is applied to the solvent and/or to the active ingredient retained in the support. 
   
   
       11 . A method according to  claim 1 , wherein the doses of liquid solution are dispensed from a liquid reservoir. 
   
   
       12 . A method according to  claim 1 , wherein the doses of liquid solution are dispensed in a coordinated manner in two different liquid retaining supports at different instants in time, such that the active ingredient without solvent is always available in at least one of said supports. 
   
   
       13 . A method according to  claim 1 , wherein the active ingredient is an insecticide and/or a perfume. 
   
   
       14 . A method according to  claim 1 , wherein the doses of liquid solution are dispensed by means of dripping. 
   
   
       15 . A method according to  claim 1 , wherein the doses of liquid solution are dispensed by means of a spray or an aerosol. 
   
   
       16 . A method according to  claim 1 , wherein the doses of liquid solution are dispensed by means of breaking capsules containing the liquid solution. 
   
   
       17 . A device to evaporate active ingredients from a liquid solution, comprising:
 a casing provided with at least one opening for the passage of air;   a reservoir containing said liquid solution comprising a solvent and at least one type of active ingredient;   at least one liquid retaining support and dispensing means arranged in the casing such that doses of said liquid solution can be dispensed on said support; and   a timer adapted to allow operation of said dispensing means in selected time periods;   wherein said timer device is adapted such that said time periods are greater than the time necessary to evaporate most of the solvent and active ingredient from the support.   
   
   
       18 . A device according to  claim 17 , wherein the timer device is programmed to a time period corresponding to the time between the metering of two consecutive doses, said time period being similar to the time necessary to evaporate the solvent and the active ingredient from the support. 
   
   
       19 . A device according to  claim 17 , wherein the liquid retaining support is housed inside the casing arranged between the air outlet and the dispensing means. 
   
   
       20 . A device according to  claim 17 , having a fan arranged in said casing such that it can provide an air stream on said support. 
   
   
       21 . A device according to  claim 20 , wherein said fan can be activated by means of said timer. 
   
   
       22 . A device according to  claim 17 , wherein the reservoir is visible from outside the casing, and is made of a transparent or translucent material. 
   
   
       23 . A device according to  claim 17 , having a push-button assembled in the casing and a rocker intended to make contact at a first end with an inner end of the push-button and at an opposite end with an electric contact provided in the electric circuit for its activation. 
   
   
       24 . A device according to  claim 17 , having a signaling luminous element which can be activated by action of the timer. 
   
   
       25 . A device according to  claim 17 , having heating means arranged inside the casing such that they can heat components of the liquid solution retained by the support. 
   
   
       26 . A device according to  claim 17 , wherein the device is a portable battery-powered device. 
   
   
       27 . A device according to  claim 17 , wherein the liquid retaining support is manufactured in a material selected from: paper, cardboard, cloth, unwoven cloth, ceramic, carbon fiber or thermoplastic. 
   
   
       28 . A device according to  claim 27 , wherein the liquid retaining support is made of a porous material having a liquid absorption capacity less than 1 g/cm 3 . 
   
   
       29 . A device according to  claim 28 , wherein the liquid absorption capacity is less than 0.1 g/cm 3 . 
   
   
       30 . A device according to  claim 17 , wherein the solvent product is selected to obtain a vapor pressure at room temperature that is equal to or greater than 0.08 mmHg. 
   
   
       31 . A device according to  claim 17 , wherein the solvent is a solvent or a mixture of solvents selected to achieve a surface tension at 25° C. that is equal to or less than 26 mM/m. 
   
   
       32 . A device according to  claim 17 , wherein the concentration of active ingredient in the liquid solution is comprised between 5 to 70% w/w of active ingredient. 
   
   
       33 . A device according to  claim 32 , wherein the concentration of active ingredient in the liquid solution is comprised between 20 to 65% w/w. 
   
   
       34 . A device according to  claim 17 , wherein the active ingredient is not soluble in the solvent. 
   
   
       35 . A device according to  claim 17 , wherein the solvent comprising at least one of: water, low molecular weight alcohols, ethanol, methanol, surfactants, anionic surfactants, ionic surfactants, amphoteric surfactants and any combination of the above. 
   
   
       36 . A device according to  claim 17 , wherein the solvent is a solvent composition comprising a first solvent in which the active ingredient is soluble and a second solvent in which the active ingredient is not soluble, wherein both solvents are mixed together. 
   
   
       37 . A device according to  claim 36 , wherein the primer solvent comprises at least one of: organic solvents, isoparaffins, propylene glycol ethers, dearomatized hydrocarbons, naphthenic hydrocarbons and acetone. 
   
   
       38 . A device according to  claim 36 , wherein the second solvent comprises at least one of: water, low molecular weight alcohols, ethanol, methanol. 
   
   
       39 . A device according to  claim 36 , wherein the amount of the first solvent is less than 30% w/w of the solvent composition. 
   
   
       40 . A device according to  claim 17 , wherein the dispensing means are dripping means which can dispense droplets of the liquid solution. 
   
   
       41 . A device according to  claim 17 , wherein the dispensing means are an aerosol or a spray coupled to the reservoir containing the liquid solution. 
   
   
       42 . A device according to  claim 17 , wherein the dispensing means are adapted to meter a dose of liquid solution by means of breaking capsules or microcapsules containing said liquid solution. 
   
   
       43 . A device according to  claim 17 , further comprising a first and a second liquid retaining support, wherein the dispensing means are adapted to dispense doses of the liquid solution in each of said supports, wherein the dispensing means are controlled by the timer to dispense in a coordinated manner doses of the liquid solution in each of the supports at different instants in time such that the active ingredient in solid state is always present in at least one of the supports. 
   
   
       44 . A device according to  claim 17 , further comprising securing means to be fixed on the body of a person or animal.