Aerosol dispenser

To date, the best aerosol pressure nebulizers for spraying active ingredients have been structures in which the propellant is in the gas and liquid phases and the liquid propellant mixes with the liquid active ingredient under pressure in the tank because it is either miscible or soluble in or emulsified in the liquid active ingredient. The propellant is selected from those that evaporate rapidly at room temperature. The static pressure generated by the propellant in the tank forces the propellant and active ingredient solution or emulsion through the discharge port when the spray valve is opened. The propellant evaporates rapidly in the discharge opening as the jet comes out and thus helps to disperse the jet into finely divided droplets of active ingredient which are substantially free of propellant residues.

Chlorofluorocarbon type compounds (hereinafter fluorocarbon) are most commonly used in spray systems. These materials have recently been the subject of discussions in environmental protection due to the adverse effects that these substances may have on the consumption of atmospheric ozone. Due to the uncertainty about the effect of fluorocarbons on the ozone layer, the aerosol industry must be prepared for a possible ban on these substances or a restriction on their use as propellants. Although liquid fluorocarbon-free propellants, namely hydrocarbons such as propane, butane and isobutane, are available, their use with solvent-based active ingredients such as alcohol has raised ignition problems. These ignition problems can be reduced by using aqueous systems in which the propellant is a separate liquid or emulsion, but such previously known spray systems require a high amount of propellant and their spray properties have not been as desired. The problem is due to the large and uneven droplet size and insufficient drying rate. Therefore, in systems where the propellant and active ingredient are substantially immiscible, there is a compelling need for a pressure sprayer that provides a jet with properties similar to those in which the propellant and active ingredient are soluble.

In systems using an insoluble propellant, mechanical means have been used to disintegrate the active ingredient into a finely divided dispersion. For example, a common mechanical means is to place a chamber in or near the discharge orifice to centrifugally vortex the active agent prior to discharge. Pressure spray valves with vapor holes or openings in communication with the propellant vapor in the upper space of the tank also aid in mechanical disintegration by feeding the propellant vapor into the active ingredient stream before it enters the vortex chamber. In general, the spray properties of systems using insoluble propellant, such as small droplet size, uniformity of distribution, and jet shape in mechanically produced showers, are inferior to those using systems using solutes.

One possibility to spray the active ingredient as a finely divided dispersion when the propellant is insoluble in the active ingredient is to use the funnel sol method, as disclosed in U.S. Patent Nos. 3,326,469 and 3,437,272. The active ingredient and the propellant are kept in different containers, whereby the active ingredient is stored at normal pressure and the propellant at a significantly higher pressure. The propellant gas stream, by means of the Bernoulli effect, creates a vacuum which sucks the active ingredient into a funnel sol device, where the active ingredient stream is divided into small droplets when it encounters the propellant stream. Such funnel salt devices can provide acceptable spray properties, but their disadvantage is the need to keep the active ingredient and propellant in different containers, which makes product and system handling more difficult for producers and users. Valve-controlled aerosol pressure nebulizers in which the supply of active ingredient and propellant from the same container to the nebulizer is simultaneous and separate, in which the active agent and propellant are in contact with each other in the container and in which the valve and pressure knob

The present invention provides a single-container aerosol pressure nebulizer in which the active ingredient and the propellant can be immiscible and whose spray properties are satisfactory. The present invention makes it possible to use inexpensive hydrocarbon propellants such as butane, isobutane and propane and allows the spraying of aqueous products, while still having jet properties at least as good as with previous soluble systems. Flammable propellants can be safely used to spray aqueous active ingredients because the presence of water in the shower prevents ignition. Furthermore, the ratio of propellant to active ingredient required for excellent spray quality is much lower, resulting in lower costs compared to systems using solutes. For example, conventional hair clips require the same amount of fluorocarbon propellant as the other components in the mixture, while according to the invention, the propellant can be used with 1/5 to 1/10 of the weight of the other components of the compound with the same spray properties. From the outside, the aerosol pressure nebulizer of the present invention looks and works in the same manner as the soluble meal aerosol nebulizers familiar to the consumer.

In addition, the structure according to the invention is such that existing filling devices can be used.

Although the present invention is applicable to systems in which the liquid propellant and active ingredient are soluble or emulsifiable with each other and it is believed that application of this invention would improve the spray properties of the discharged active ingredient, the invention is most needed in systems where the propellant is immiscible with the liquid active ingredient. immiscible and the active ingredient is water-based.

Strictly speaking, the valve unit according to the invention is characterized by a funnel ejector part located in a recess in the bottom of the valve housing or formed as part of the bottom of the valve housing and comprising a collision mixing chamber and . The valve unit according to the invention thus comprises separate channels for the active substance and the propellant, which lead from the tank to the collision mixing chamber. There are no valves or other parts inside the mixing chamber and it is designed so that the jet streams entering the chamber at high velocity collide and penetrate each other (fragmentation, shear or combined shock and shear depending on the inlet angles and the relative positions of the streams in the chamber). . The second channel leading to the chamber preferably has a funnel dilution which, together with the chamber, forms a funnel ejector. In addition to improving the impact performance, the funnel thinning allows, by providing a vacuum effect, the use of a lower vapor pressure in the propellant. In a preferred embodiment of the invention, a turbulent stream pattern is created in the mixing chamber, which causes rapid and thorough mixing of the active ingredient and the propellant.

As stated above, the invention comprises a valve unit for spraying liquid from a tank by means of a gaseous propellant pressurized in said tank, said valve unit comprising a valve body comprising a discharge channel device and a valve pushbutton connected to a collision mixing chamber for simultaneously and separately supplying unobstructed liquid and gas streams to said chamber using a valve pushbutton to impinge on said second stream with another, thereby generating a fine dispersion between the two phases in said chamber.

According to the invention, the collision mixing chamber is preferably part of the funnel ejector and one of the streams is fed into the chamber preferably in the axial direction through the funnel dilution. According to a preferred embodiment, a second stream is fed tangentially to provide a turbulent flow line pattern to the chamber. The valve unit has a discharge opening from which the streams, after being mixed in the mixing chamber, are sprayed out as a fine dispersion.

The invention thus makes it possible to provide a pressurized aerosol pressure nebulizer comprising a container for storing a liquid and a propellant under pressure and a valve unit as previously described. The liquid is preferably aqueous in nature and the propellant is preferably a hydrocarbon.

In a preferred embodiment, either the propellant or the active ingredient can be fed through the central channel and one of them is fed through the annular channel surrounding the first channel.

With the chamber placed in the valve, it was surprisingly found that the showers were very satisfactory. Therefore, the chamber is located in the valve housing, a location that does not require that separate propellant and active agent channels be provided with valves. In this way, any existing valve can be used by simply attaching a funnel chamber to it, which makes manufacture quite easy. Given that the chamber can be placed in the form of a plug in the lower part of the housing, into which the riser normally enters, another embodiment provides for its location inside the valve housing.

In a possible embodiment, the chamber can furthermore be placed in the valve stem just in the area of ​​the valve seal. Although this structure requires separately controlled channels for active agent and propellant, these channels may terminate in the region of the valve seal. In all embodiments, there is sufficient propellant residue in the dispersion to clean the passages downstream of the valve and thus prevent agglomeration or drying of the active agent in the discharge orifices.

In order to provide a convenient and efficient method of transferring propellant and active ingredient from a container in which both are under the same pressure, a preferred embodiment of the invention provides a valve unit comprising a valve housing with one movable, hollow valve body and one annular, flexible valve seal and spring pushes the valve body up towards the end of the can.

The design of the valve and the design and location of the ejector unit and the collision mixing chamber may vary, as will be seen from the following description. The best results are obtained when the mixing chamber is made so that one stream has a vortex streamline pattern and the other stream is injected through the funnel solo dilution axially with respect to the vortex streamline pattern.

In the following description, the invention is presented in connection with an immiscible propellant / active ingredient system. The tank is in contact with each other in three separate layered phases, namely propellant vapor, liquid propellant and liquid active ingredient. The density of the liquid phase of the propellant is usually lower than that of the liquid active ingredient and the insoluble liquid phases of the propellant and active ingredient are deposited in the tank as the propellant floats on top of the active ingredient.

The accompanying drawings illustrate exemplary embodiments of the invention. In the drawings:

Fig. 1 is a vertical sectional view of a valve and pushbutton according to an embodiment of the invention; Fig. 2 is a horizontal sectional view taken along line II-II of Fig. 1. Fig. 3 is a vertical sectional view of a valve and pushbutton modification of Fig. a vertical sectional view (part) of a further modification of the embodiments of Figures 1-4.

Figures 1-4 show an embodiment in which a collision mixing chamber causing a funnel-sol effect is located at the bottom of the valve housing.

In Figure 1, the push button is indicated by reference numeral 50. The valve housing 501 is attached to a conventional container closure portion 70 by means of flanges 72. The valve housing 501 has a hollow portion 503 defining a recess 505. A compression spring 511 pushes the vertically movable valve body 509 upward toward the closure. Valve body

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509 is integral with the valve stem 513 which passes through an opening in the closure portion 70 of the container and to the end of which the pressure knob 50 is frictionally attached. The valve stem 513 has a central passage 515 surrounded concentrically by an annular passage 517. The valve stem 513 has transverse holes 519 and 521 which communicate with the central passage 515 and the concentric annular passage 517, respectively.

Holes 519 and 521 are blocked by a flexible seal 523 when the valve is closed, and both are open for flow when the valve is open.

A collision mixing chamber 541 is formed in the recess 505 by means of the member 525. The member 525 has a base portion 533 which is outside the recess 505 and shaped to fit the active substance riser 536 by frictional attachment.

The bottom portion 533 of the member 525 is spaced apart from the edge of the wall of the recess 505 to create an annular space 535. The inner wall of the portion 503 has a plurality of vertical wall-long grooves 537 internally communicating with the annular recess 539 and the opening 535 outside the recess.

The upper surface of the member 525 is best seen in Figure 2. The portion 503 has grooves 537. The grooves 537 communicate with the annular recess 539 of the member 525.

In use, pressing the pushbutton 50 causes the movable valve body to move downwardly against the spring 511 and opens the openings 519 and 521 by causing the flexible seal 523 to bend. When the valve opens, the propellant gas flows through the openings and passages 535, 537 and 542 into the mixing chamber 541. The pressure in the mixing chamber 541, which was substantially the same as at the inlet prior to use, drops substantially when the chamber is contacted with outside air through holes 519 and 521, passages 515 and 517, and a pushbutton 50 in the valve body 501. In the mixing chamber, the swirling propellant impinges on the active ingredient, which enters the chamber through the riser 536 and the funnel soleplate 529 in the portion 503 and forms a fine gas dispersion in the liquid. The dispersion passes through the opening 507, the interior of the valve housing 501 and then the openings 519 and 521 into the channels 515 and 517 of the valve stem 513.

As shown in Figure 1, a mixture of propellant and active agent passes through a push-button 50 with an additional mixing chamber similar to that described in the base portion 533.

It should be noted, as shown in Figure 2, that each groove 542 is positioned so that its extension engages the chamber 541 eccentrically, causing a vortex movement therein.

Figure 3 is the same as the embodiment of Figure 1, except that the valve body 543 is a hollow, inverted cup-like portion. The shoulder 545a of the valve body 543 has a plurality of holes 545 to facilitate the flow of a mixture of propellant and active agent into the holes and passages of the valve stem. The retainer of the spring 547 is a ring ball.

Figure 4 is the same as the embodiment of Figures 1 and 3, except that the valve stem 513 has a single passage 515 to accommodate any conventional aerosol push button.

Figure 5 shows a further modification of the invention in which the collision mixing chamber 601 is located inside the valve housing 600. As in the embodiment of Figure 3, the housing has a central opening with a funnel ejector portion for supplying the active ingredient to the chamber 601. The chamber 601 and its supply channels are formed by a housing base 606 and a disc-shaped portion 603 resting on the housing base. A mixing chamber 601, transverse channels 607 and an annular recess 604 are formed in the base 606, which are similar in shape to the corresponding structures in Figure 2. The openings 609 for supplying propellant gas to and from the transverse channels are at the bottom outside the active agent supply channel 602. The spring 605 is placed on the disc-shaped part 603 and presses the disc part against the inside of the housing bottom during operation.

By placing the collision mixing chamber inside the tank, the active ingredient is prevented from drying out or otherwise adversely altering the discharge channels of the unit. Inside the tank, there is an active substance in the channels surrounded by the contents of the tank, so it does not dry out and is not exposed to changes caused by the outside air. When the valve is dry, the eddy discharges caused by the expanding propellant clean up any propellant-active compound noise on the outside air side of the valve opening.

The above examples are not intended to limit the invention in any way, but the invention can, of course, be modified in many different ways within the scope of the claims.