Passive emanator

Abstract

A passive diffuser (2) is described. The passive diffuser (2), in particular for a fragrance, comprises a container (12) comprising a liquid composition (16) to be evaporated and diffused from the diffuser via ambient air, a porous wick (20) emerging in the liquid composition (16), and a porous membrane (18) arranged above the liquid level of the liquid composition (16), wherein the membrane (18) is in contact with the wick (20) such that the membrane (18) is saturated with the liquid composition (16) via the wick (20) and an outer surface of the membrane (18) is in contact with the ambient air. The liquid composition (16) comprises a first solvent (in particular DMM), a second solvent (in particular DPM), and a fragrance or insect repellent. The DMM and DPM are present in the liquid composition (16) in a weight ratio between 1:5 and 1:7, preferably in a weight ratio of 1:6, and most preferably in a weight ratio of 1:6.4.

Description

Technical Field

[0001] This invention relates to a device for the controlled-rate release of volatile substances, particularly liquids comprising fragrances or insect repellents. Specifically, this invention relates to an air purifier that operates based on the principle of liquid-phase transfer of a liquid fragrance composition through a porous membrane. Background Technology

[0002] As is well known, the purpose of an air purifier is to release fragrance or deodorizing active ingredients into an environment such as a room in a house. Passive and active air purifiers are available. The latter releases active ingredients at regular intervals, while the former relies on volatile components, such as evaporation at room temperature, without requiring an external energy source to assist in the release of active ingredients.

[0003] Many existing passive air purifiers initially deliver a large amount of fragrance, followed by a gradual reduction in the amount of fragrance. The initial large dose is often "too much" and therefore offensive, while the subsequent doses are "not enough" and sometimes even undetectable. Summary of the Invention

[0004] The object of this invention is to disclose an improved passive diffuser. Specifically, the object of this invention is to provide a passive diffuser that delivers fragrance at a uniform rate over an extended period of time.

[0005] The passive diffuser according to the invention comprises: a container including a liquid composition to be evaporated and diffused from the diffuser via ambient air; a porous core appearing in the liquid composition; and a porous membrane disposed above a horizontal plane of the liquid composition, wherein the membrane is in contact with the core such that the membrane is permeated with the liquid composition via the core, and the outer surface of the membrane is in contact with ambient air. The liquid composition includes a first solvent and a second solvent, as well as a fragrance or insect repellent. The first solvent is dipropylene glycol dimethyl ether (DMM), and the second solvent is dipropylene glycol monomethyl ether (DPM). The inventors have found that including DMM in the liquid composition contributes to the desired uniform evaporation because its high vapor pressure introduces a generally higher vapor pressure into the DMM / DPM mixture. The weight ratio between DMM and DPM is between 1:5 and 1:7, preferably 1:6, and most preferably 1:6.4. The inventors have found that this weight ratio excellently supports an extended time period of approximately 45 to 60 days during which the composition evaporates at a substantially uniform rate.

[0006] This passive system provides continuous, consistent fragrance / scent dissipation throughout the lifespan of the composition by using a core and membrane (e.g., a liner), which can be incorporated into the container to provide substantially linear weight loss of the composition over an extended period of its lifespan. The core is present in the composition and guides the composition to the membrane via capillary action, ensuring the membrane remains permeable as long as the composition is not depleted. The outer surface of the membrane is in contact with the surrounding air, thus dissipating the composition uniformly into the surrounding air over time.

[0007] In a preferred embodiment, the membrane covers the liquid composition such that the outer surface of the membrane is the same size as the surface of the composition facing the surrounding air. In this embodiment, the outer surface of the membrane in contact with the surrounding air is the only surface through which the composition evaporates. Since there is no evaporation “leak” of the composition below, and the core that keeps the membrane impregnated is included, this embodiment provides improved uniform dissipation by supporting linear weight loss of the composition over an extended period of time.

[0008] Flash point and evaporation rate of DPM and DMM: 1. Dowanol DPM ® Dipropylene glycol methyl ether with a flash point of 75°C and an evaporation rate of 3 is available from Dow Chemical Company.

[0009] 2. Proglyde DMM ® Dipropylene glycol dimethyl ether with a flash point of 65°C and an evaporation rate of 80 is available from Dow Chemical Company.

[0010] The evaporation rates mentioned above are relative to butyl acetate with an evaporation rate of 100; Proglyde DMM ® The value was calculated as molecular weight x vapor pressure (mmHg at 20°C).

[0011] Preferably, based on the total weight of the liquid composition, the first solvent is present in the liquid composition at a percentage between 5% and 15% by weight, the second solvent is present in the liquid composition at a percentage between 30% and 70% by weight, and the fragrance or insect repellent is present in the liquid composition at a percentage between 20% and 40% by weight.

[0012] The core and the membrane may comprise polypropylene (PP) and / or polyethylene (PE) fibers, and are preferably hydrophobic, such that the membrane is ensured to be impregnated using only the composition.

[0013] The passive diffuser may further include a fan, wherein an airflow generated by the fan is directed toward the membrane. Preferably, the fan can operate at different speeds. In this embodiment, the fan supports the dissipation of the evaporated composition into the surrounding air and can increase the accessibility of the diffuser. Furthermore, selecting different fan speeds supports the selection of different dissipation rates.

[0014] In another embodiment, the container, the core, the membrane, and the fan are integrated into a housing, wherein the housing has at least one inlet opening for drawing in air and at least one outlet opening for directing the airflow generated by the fan into the environment. Attached Figure Description

[0015] The invention will be described in more detail below.

[0016] Figure 1 A passive emitter according to the present invention is shown. Detailed Implementation

[0017] The figure shows an example of a passive diffuser. The passive diffuser 2 includes a solar panel 4, a drive circuit 6, an electromagnet 8, a fan 10, at least one magnet 14, and a container 12 for containing a volatile liquid composition.

[0018] Solar panel 4 is connected to drive circuit 6, which is connected to electromagnet 8. Fan 10 is connected to at least one magnet 14. Fan 10 is positioned close to electromagnet 8 such that the magnetic field generated by electromagnet is strong enough to attract or repel at least one magnet 14. Fan 10 is positioned close to container 12 such that the fan increases airflow and increases the distribution of volatile substances.

[0019] In the example illustrated in the figure, the drive circuit is configured to receive power from solar panel 4. The power received from the solar panel can be stored by the drive circuit using, for example, a battery. The power received from solar panel 4 is used to drive electromagnet 8, and the current driven by the electromagnet generates a magnetic field. This magnetic field can be changed by altering the magnitude and direction of the current. For example, the magnetic poles of electromagnet 8 can be switched by changing the direction of the current.

[0020] Container 12 includes a liquid composition 16 to be evaporated by diffuser 2. A core 20 is present in the liquid composition 16 and in contact with a membrane 18, which may be a liner comprising PE and / or PP fibers. Furthermore, the core may comprise PE and / or PP fibers.

[0021] The core 20 attracts the liquid composition 16 through capillary action and impregnates the membrane 18 with the liquid composition 16.

[0022] Liquid composition 16 comprises a first solvent (dipropylene glycol dimethyl ether, DMM) and a second solvent (dipropylene glycol monomethyl ether, DPM). DMM and DPM are present in the liquid composition in a weight ratio between 1:5 and 1:7, preferably 1:6, and most preferably 1:6.4. Liquid composition 16 also includes a fragrance agent, which is present in the liquid composition at a percentage between 20% and 40% by weight, based on the total weight of the liquid composition.

[0023] The airflow generated by the fan 10 is directed toward the membrane 18, so that the evaporative liquid composition 16, which is mixed with the fragrance, is distributed into the surrounding air through the outlet opening of the diffuser 2.

[0024] The fan 10 can operate at different speeds, allowing the radiator 2 to be adjusted as needed.

[0025] Examples of five liquid compositions suitable for use with the dispenser shown above are: weight% DMM 10 6 8.11 9.45 8.10 DPM 64 38.4 51.9 60.45 51.82 Isoalkanes (EU) 0 0 0 0.10 0.08 Fragrance 26 55.6 39.9 30 40 As shown in the table above, the liquid composition may contain a third solvent (here: a relatively small amount of isoalkanes (EU)).

[0026] The following graph illustrates the typical weight loss characteristics of the liquid composition over time according to the example given above. A comparison was made between the characteristics with and without a core and film. The upper solid line represents the liquid composition evaporating over time without a core and film. This liquid composition is in direct contact with the surrounding air. It can be seen that the choice of solvent according to the invention has achieved an approximately uniform evaporation profile over a period of time.

[0027] The second solid line diagram below the upper solid line diagram shows the same liquid composition now evaporating, including the core and the membrane, such that the liquid composition is evaporated via the outer surface of the membrane.

[0028] As can be seen, the second solid line graph shows a better linear approximation of the weight loss of the liquid composition over the extended time period compared to the upper solid line graph. This implies that the liquid composition exhibits an even more uniform fragrance emission rate when using a core and membrane.

[0029] For clarity, the figure also includes a dashed plot, which shows the upper solid line plot and the second solid line plot for linearization. It is evident that the upper solid line plot (without the core and membrane) deviates more from the corresponding linearized plot than the second solid line plot (with the core and membrane).

[0030] Therefore, it can be concluded that the choice of solvent according to the invention, combined with the core and membrane, exhibits a synergistic effect, thereby achieving a good approximation of the linear weight loss of the liquid composition over time, resulting in a uniform evaporation profile and aroma experience over time.

[0031] Weight loss of formulations with and without core and liner

[0032] The following figure illustrates the weight loss curves over time (here: more than 25 days) in relation to a passive diffuser comprising a liquid composition according to the invention (the passive diffuser includes two different fragrance concentrations (referred to as “minimum” and “maximum”, respectively) and a fan for dispensing the fragrance). The case with the fan activated (see the first and second curves in the figure) and the case with the fan deactivated (“off”, see the third curve at the bottom of the figure) are described.

[0033] The liquid composition is also a liquid composition containing DMM and DPM, wherein the weight ratio of DMM to DPM is between 1:5 and 1:7, preferably 1:6, and most preferably 1:6.4.

[0034] The first curve (“minimum”) relates to a liquid composition comprising a low concentration of fragrance when the fan is running.

[0035] The second curve (“maximum”) relates to a liquid composition containing a high concentration of fragrance when the fan is running.

[0036] As can be seen, both the first and second curves exhibit a substantially linear weight loss characteristic over time. It can also be seen that the fragrance loading affects the steepness of the (substantially linear) weight loss curve. The steepness of the curve can also be affected by changing the airflow from the fan directed towards the liquid composition. By weighting one or both of the parameters and selecting them accordingly, the desired weight loss characteristics of the liquid composition over time can be achieved.

[0037] The third curve (“Off”) relates to a passive diffuser with the fan off, which comprises a liquid composition and includes a fragrance. It can be seen that the weight loss over time is largely linear, but much less steep – meaning that significantly less fragrance is dispensed into, for example, the room compared to when the fan is on (activated).

[0038] These curves begin to plateau at the end of the liquid composition's lifespan (more than 25 days or more, not shown here), and there are no visible residues in the passive emitter's container at the end of its lifespan.

[0039]

Claims

1. A passive diffuser (2) for fragrances, said passive diffuser (2) comprising: Container (12), the container comprising a liquid composition (16) to be evaporated and dispersed from the emitter (2) via ambient air; Porous core (20), which appears in the liquid composition (16); and A porous membrane (18) is disposed above the horizontal plane of the liquid composition (16), wherein: The membrane (18) is in contact with the core (20) such that the membrane (18) is permeated by the liquid composition (16) through the core (20); The outer surface of the membrane (18) is in contact with the surrounding air, and the liquid composition (16) comprises: First solvent; Second solvent; and Fragrance or insect repellent, The first solvent is dipropylene glycol dimethyl ether (DMM), and the second solvent is dipropylene glycol monomethyl ether (DPM), wherein the DMM and DPM are present in the liquid composition in a weight ratio between 1:5 and 1:

7. Based on the total weight of the liquid composition, the first solvent is present in the liquid composition at a percentage between 5% and 15% by weight; Based on the total weight of the liquid composition, the second solvent is present in the liquid composition at a percentage between 30% and 70% by weight; and Based on the total weight of the liquid composition, the fragrance or insect repellent is present in the liquid composition at a percentage between 20% and 60% by weight.

2. The passive diffuser (2) according to claim 1, wherein, The membrane (18) covers the liquid composition (16).

3. The passive diffuser (2) according to claim 1 or 2, wherein, The core (20) and the membrane (18) comprise polypropylene (PP) and / or polyethylene (PE) fibers.

4. The passive diffuser (2) according to claim 1 or 2, wherein, The core (20) and the membrane (18) are hydrophobic.

5. The passive radiator (2) according to claim 1, wherein the passive radiator further comprises a fan (10), wherein, The airflow generated by the fan (10) is directed to the membrane.

6. The passive diffuser (2) according to claim 5, wherein, The fan (10) can operate at different speeds.

7. The passive diffuser (2) according to claim 5 or 6, wherein, The container (12), the core (20), the membrane (18) and the fan (10) are integrated into a housing, wherein the housing has at least one inlet opening for drawing in air and at least one outlet opening for directing the airflow generated by the fan (10) to the environment.

8. The passive diffuser (2) according to claim 1, wherein, The DMM and DPM are present in the liquid composition at a weight ratio of 1:

6.

9. The passive diffuser (2) according to claim 1, wherein, The DMM and DPM are present in the liquid composition at a weight ratio of 1:6.4.

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