MXPA98000928A - Method to disinfect the a - Google Patents

Abstract

A method is described for disinfecting air and killing airborne bacteria, etc. by creating particles of disinfectant compounds using a heated wick. More particularly, this invention relates to a method for generating particles of compounds. which are known to kill bacteria carried by the air when these compounds are dispersed in the air in the form of small particles by generating particles using a wick, which is heated indirectly near the top. The compositions include glycols selected from the group consisting of propylene glycol, dipropylene glycol, triethylene glycol and mixtures thereof.

Description

METHOD FOR DISINFECTING AIR TECHNICAL FIELD The present invention relates to a method for disinfecting air and killing bacteria carried by air, etc. , by creating particles of disinfectant compounds using a heated wick.

More particularly, this invention relates to a method for generating particles of compounds, which are known to kill airborne bacteria when these compounds are dispersed in the air in the form of small particles by generating these particles using a wick, the which is heated indirectly in or near the top.

BACKGROUND ART The use of indirect heating as a method to create fumigant compounds for insecticidal materials has been known for a long time. An example of these types of compositions and methods are those described in U.S. Patent 4,745,705. This patent discloses a method for delivering insecticides using a porous absorbent wick, which is immersed in an insecticide solution and indirectly heating the wick at the top to vaporize the solution absorbed into the atmosphere. There is no disclosure in this patent that insecticides are dispersed in the air as particles.

In addition, there have been a number of patents which describe devices for delivering insecticides using a porous wick. These patents include US5095647, US4663315, US5038394 and US5290546. None of these patents describe that these devices can be used to generate particles of an air-disinfecting agent. Also, certain glycol compounds have been known to provide some sanitation when atomized in the air.

Generally, it has been found that these effective amounts are about 5% or more of active glycol. (Document US EPA dated September 3, 1980) SUMMARY OF THE INVENTION The present invention relates to a method for disinfecting air comprising submerging a portion of a porous wick in a liquid disinfectant composition, and indirectly heating the top of said wick to generate particles of said liquid disinfecting agent in the air. , wherein at least 90% of the particles generated have a particle size of not more than 10 microns.

BRIEF DESCRIPTION OF THE DRAWINGS The attached drawing is a schematic view of a device used in the method of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION As noted above, it is well known that certain air sanitizing agents or air disinfectants must be present in the air in some form in order to be active. Applicants believe that the agents must be in the form of particles and / or bind themselves to particles that are already in the air, such as dust particles to be active. Accordingly, any such sanitizing or air disinfecting agents, which can be dispensed in the form of particles from a heated wick generator can be used in the method of the present invention. However, it is preferred that certain glycol compounds are used since these materials readily generate particles, which form an aerosol suspension in the air at temperatures that can be used safely in a small consumer apparatus. Preferred glycol materials are propylene glycol, dipropylene glycol, triethylene glycol, and mixtures thereof. Of these glycol materials, the most preferred compound is dipropylene glycol. Since many of the air sanitizing active materials are water soluble, the most preferred diluent for use in the method of the present invention is water. Other diluents, solvents and cosolvents may be used, however, it is believed that highly volatile hydrocarbon solvents decrease the effectiveness of the method of the present invention and should be avoided in general. In addition, other volatile materials such as perfumes should also be avoided or used in small quantities, generally less than 15% of the total formulation. It is preferred that the formulations useful in the method of the present invention are essentially perfume-free. The particular concentration of the active material in the concentrate contained within the package suitable for use in the method of the present invention can vary from as low as about 5% active to 100% active material. In this regard, small amounts of fragrance or perfume agents can also be included without having an adverse effect on the sanitizing effect of the air of the active ingredient. Conversely, the amount of diluent present varies inversely with the amount of active from 0% diluent to 100% active material to about 95% diluent to about 5% active material. The preferred diluent materials are solvents for the active materials. For glycols, the preferred diluent is water. Turning now to the schematic drawing of the present invention, the present invention comprises an outer shell or a container 10 which contains therein in the upper part an opening 20. Located on the periphery of the opening 20 is a heating element 30. This element can be any conventional heating element such as ring heaters, wound wire heaters or one or more PTC heaters (positive temperature coefficient). The particular type of heating element is not critical to the present invention. As long as the heating element is capable of heating the upper portion of the wick 40 to a temperature in the range from about 50 to about 120 ° C. The heating element 30 is connected by the conductor 70 to a source of electrical energy. This can be a battery or a homemade outlet. The wick 40 can be made of any conventional material used for these types of wicks. Suitable materials include porous ceramic wicks and the like. Suitable wicking materials are described in US 4663315, the disclosure of which is incorporated by reference. Preferred wicking materials are ceramics, polyester, compressed wood, agglomerated polyethylene and polypropylene, and carbon fibers. The wick 40 is placed in the opening of a package 50. Preferably, the wick 40 is placed in the opening of the package 50 in a sealed manner, so that the liquid air sanitizing material 60 within the package 50 can not be removed easily. The means for sealing the wick 40 in the opening of the package 50 is conventional and does not form part of the present invention. It was surprising that the previous type of evaporator unit would generate air sanitizer particles in a range where these known sanitizing materials would be active. It has been observed that the above units will generate particles so that over 90% of the particles have a particle size in the range from about 0.16 to about 5 microns. Within this range of particle size sanitizing materials are very effective. The present method will now be illustrated by the following examples, which are for the purpose of illustration only and should not be considered as limiting.

Example 1 The following formulation was prepared: Components Percent by weight Dipropylene glycol 90 Fragrance (TBA73299) 10 45 grams of the previous formulation were placed in a bottle with a ceramic wick having an average pore size of 0.7 microns. The bottle and wick combination was then placed in an electric heating unit, which heated the upper portion of the wick to a temperature of about 100 ° C. The unit was placed in a room with temperature and humidity controlled at 22 ° C and 40% RH. The room was also equipped with a Met One # 200 Clean Room particle counter and Mattson-Garvin 220 agar groove sampler, which measures the number of bacterial colonies over time. After approximately 24 hours, a bacteria transported through the air, micrococcus lutens lysodiekticus, was introduced into the room. The total particle count as well as the relative particle sizes of the particles were measured. In addition, the decrease in the number of colonies was measured over time. A control room without any unit to generate particles also had the decrease in the number of colonies of the measured bacteria. The previous unit generated 6.39 million particles after a period of 24 hours. The weight loss of the formula of the bottle throughout that time was 1.67 grams. In the following table, 10-15 refers to 10-15 minutes of the introduction of the bacteria in the room. The bacterial colon counts were as follows: 0-5 10-15 20-25 30-35 40-45 50-55 Ex 1 1 0 0 0 0 0 Control 293 183 146 1 13 77 44 It is clear that the method reduces the amount of bacteria transported in the air after only a short period of time.

Example 2 The procedure of Example 1 was repeated except that the following formulation was used.

Components Percentage by weight Triethylene glycol 10 Deionised water 90 The number of particles generated over a 24-hour period was 3.1 million and the weight loss was 0.98 grams. The following results were observed: 0-5 10-15 20-25 30-35 40-45 50-55 Ex 2 28 10 5 5 2 4 Control 322 256 161 134 1 10 77 Again, there was a substantial reduction in the amount of bacteria transported by the air present.

INDUSTRIAL APPLICABILITY The method of the present invention is useful for reducing the amount of bacteria carried by the air present in an indoor environment. Since some bacteria are known to contribute to diseases, the use of the method of the present invention can minimize the spread of certain infections.

Claims (5)

1 . A method for disinfecting the air comprising indirectly heating a porous wick having an upper portion which is located in the vicinity of a heating source, and a lower portion which is submerged in a liquid disinfectant composition, having the upper portion of the wick a temperature sufficient to generate particles of said disinfectant composition, whose particles are then dispersed in the air, wherein at least 90% of the particles that are generated have a particle size of not more than 5 microns and wherein the particles are effective to kill bacteria transported by the air.

2. The method of claim 1 wherein the wick is heated to a temperature in the range from about 50 to about 120 ° C.

3. The method of claim 1 wherein the liquid disinfectant composition includes a glycol as an active disinfecting agent.

4. The method of claim 3 wherein the glycol is selected from the group consisting of propylene glycol, dipropylene glycol, triethylene glycol and mixtures thereof. The method of claim 3 wherein the liquid disinfectant composition includes water as a diluent. The method of claim 3 wherein the liquid disinfectant composition comprises from about 5 to 100% of a glycol and from about 95 to 0% of water. The method of claim 6 wherein the glycol is dipropylene glycol. The method of claim 7 wherein the liquid disinfectant composition comprises from about 10 to 100% dipropylene glycol and from about 0 to 90% water. The method of claim 3 wherein the composition also includes less than 15% perfume. The method of claim 3 wherein the composition is essentially free of perfume.