Aerosol container with gas-permeable membrane

An aerosol container for delivering liquid aerosol compositions highly concentrated with respect to the active ingredient at a low delivery rate, comprising, in combination, a pressurizable container having a delivery valve movable between open and closed positions, a valve stem, and a delivery port;

• a valve stem orifice in the valve stem in flow connection at one end with a blending space and at the other end with an aerosol-conveying valve stem passage leading to the delivery port;
• the valve stem orifice having a diameter within the range from about 0.33 to about 0.65 mm;
• bias means for holding the valve in a closed position;
• means for manipulating the valve against the bias means to an open position for expulsion of aerosol composition via the valve stem orifice to the delivery port;
• wall means defining the blending space and separating the blending space from liquid aerosol composition and propellant within the container, at least one liquid tap orifice through the wall means, having a cross-sectional open area within the range from about 0.2 and 0.8 mm.sup.2 for flow of liquid aerosol composition into the blending space;
• at least one vapor tap orifice through the wall means, having a cross-sectinal open area within the range from about 0.2 to about 0.8 mm.sup.2 for flow of propellant into the blending space;
• the ratio of liquid tap orifice to vapor tap orifice cross-sectional open area being within the range from about 0.5 to about 2.5;
• the open areas of the liquid tap orifice and vapor tap orifice being selected within the stated ranges to provide a volume ratio of propellant:gas liquid aerosol composition within the range from about 8:1 to about 40:1, thereby limiting the delivery rate of liquid aerosol composition and propel any gas from the container when the delivery valve is opened;
• and a gas-permeable membrane that is at best only slowly permeable by liquefied propellants, disposed across the line of flow of liquefied propellant from the storage compartment to the delivery port, and impeding liquid flow via a gas tap orifice through an open manually-operated delivery valve, at least when the container is tipped from the upright position beyond the horizontal towards the fully inverted position.

An aerosol container for use with compositions containing liquefied flammable propellants, and having a gas-permeable membrane that is at best only slowly permeable by liquefied propellants, and impeding liquid flow via a gas tap orifice through an open manually-operated delivery valve, at least when the container is tipped from the upright position beyond the horizontal towards the fully inverted position, the container comprising, in combination, a pressurizable container having at least one storage compartment for an aerosol composition and a liquefied propellant in which compartment liquefied propellant can assume an orientation according to orientation of the container between a horizontal and an upright position, and a horizontal and inverted position;

• a delivery valve movable manually between open and closed positions, and including a valve stem and a delivery port;
• an aerosol-conveying passage in flow connection at one end with the storage compartment via a gas tap orifice and at the other end with the delivery port, manipulation of the delivery valve opening and closing the passage to flow of aerosol composition and propellant from the storage compartment to the delivery port;
• means defining at least two separate compartments in the container, of which a first compartment has a volume of at least 0.5 cc and is in direct flow connection with the aerosol-conveying passage, and a second compartment is in flow connection with the aerosol-conveying passage only via the first compartment;
• at least one first liquid tap orifice having a diameter within the range from about 0.012 to about 0.2 cm and communicating the first and another compartment for flow of liquid aerosol composition into the first compartment from the other compartment, and of sufficiently small dimensions to restrict flow of liquid aerosol composition therethrough;
• the ratio of first compartment volume/first orifice diameter being from about 10/x to about 400/x, where x is 1 when the orifice length is less than 1 cm, and 2 when the orifice length is 1 cm or more;
• at least one second gas tap orifice having a total cross-sectional open area within the range from about 4 .times. 10.sup.-5 to about 1.3 .times. 10.sup.-2 cm.sup.2 and communicating the first and second compartments for flow of propellant into the first compartment from the second compartment therethrough, and of sufficiently small dimensions to restrict flow of propellant gas and form bubbles of such gas in liquid aerosol composition across the line of flow thereof to the valve, thereby to foam the aerosol composition upon opening of the valve to atmospheric pressure, and to expel foamed aerosol composition through the open delivery valve;
• and a gas-permeable membrane that is at best only slowly permeable by liquefied propellants, disposed across the line of flow of liquefied propellant from the storage compartment to the delivery port, and impeding liquid flow via a gas tap orifice through an open manually-operated delivery valve, at least when the container is tipped from the upright position beyond the horizontal towards the fully inverted position.

An aerosol container for use with compositions containing liquefied flammable propellants, and having a gas-permeable membrane that is at best only slowly permeable by liquefied propellants, and impeding liquid flow via a gas tap orifice through an open manually-operated delivery valve, at least when the container is tipped from the upright position beyond the horizontal towards the fully inverted position, the container comprising, in combination, a pressurizable container having at least one storage compartment for an aerosol composition and a liquefied propellant in which compartment propellant can assume an orientation according to orientation of the container between a horizontal and an upright position, and a horizontal and an inverted position;

• a delivery valve housing;
• a chamber in the delivery valve housing, a delivery valve in the housing chamber movable manually between open and closed positions, and including a valve stem and a delivery port;
• an aerosol-conveying passage in flow connection at one end with the storage compartment via a gas tap orifice and at the other end with the delivery port, manipulation of the delivery valve opening and closing the passage to flow of aerosol composition and propellant from the storage compartment to the delivery port;
• and a gas-permeable membrane that is at best only slowly permeable by liquefied propellants, disposed in the delivery valve housing across the line of flow of liquefied propellant from the storage compartment to the delivery port, and impeding flow of liquefied propellant to the delivery port in all orientations of the container.

An aerosol container for delivering liquid aerosol compositions highly concentrated with respect to the active ingredient at a low delivery rate, comprising, in combination, a pressurizable container having a delivery valve movable between open and closed positions, a valve stem, and a delivery port;

• a valve stem orifice in the valve stem in flow connection at one end with a blending space and at the other end with an aerosol-conveying valve stem passage leading to the delivery port;
• the valve stem orifice having a diameter within the range from about 0.33 to about 0.65 mm;
• bias means for holding the valve in a closed position;
• means for manipulating the valve against the bias means to an open position for expulsion of aerosol composition via the valve stem orifice to the delivery port;
• wall means defining the blending space and separating the blending space from liquid aerosol composition and propellant within the container;
• at least one liquid tap orifice through the wall means, having a cross-sectional open area within the range from about 0.2 and 0.8 mm.sup.2 for flow of liquid aerosol composition into the blending space;
• at least one vapor tap orifice through the wall means, having a cross-sectional open area within the range from about 0.2 to about 0.8 mm.sup.2 for flow of propellant into the blending space;
• the ratio of liquid tap orifice to vapor tap orifice cross-sectional open area being within the range from about 0.5 to about 2.5;
• the open areas of the liquid tap orifice and vapor tap orifice being selected within the stated ranges to provide a volume ratio of propellant:gas liquid aerosol composition within the range from about 8:1 to about 40:1, thereby limiting the delivery rate of liquid aerosol composition and propel any gas from the container when the delivery valve is opened;
• and a gas-permeable membrane that is at best only slowly permeable by liquefied propellants, extending across the blending space across the line of flow from both the vapor tap and liquid tap orifices to the blending space, and impeding liquid flow via said orifices through an open manually-operated delivery valve in all positions of the container.

An aerosol container for use with aerosol compositions containing liquefied flammable propellants, and having a gas-permeable membrane that is at best only slowly permeable by liquefied propellants, and impeding liquid propellant flow through an open manually-operated delivery valve, at least when the container is tipped from the upright position beyond the horizontal towards the fully inverted position, the container comprising, in combination, a pressurizable container having at least one storage compartment for a liquid aerosol solution and a liquefied propellant in which compartment propellant can assume an orientation according to orientation of the container between a horizontal and an upright position, and a horizontal and an inverted position;

• a delivery valve housing;
• a chamber in the delivery valve housing;
• a delivery valve in the housing chamber movable manually between open and closed positions, and including a valve stem and a delivery port;
• an aerosol-conveying passage in flow connection at one end with the storage compartment and at the other end with the delivery port, manipulation of the delivery valve opening and closing the passage to flow of liquid aerosol solution and propellant from the storage compartment to the delivery port;
• and a gas-permeable membrane that is at best only slowly permeable by liquefied propellants, but is permeable to liquid aerosol solution being dispensed from the container;
• the membrane having a bubble point of less than 1 atmosphere, a pore size not exceeding about 25 microns, and an open area within the range from about 40 to about 90%, said membrane being disposed in the delivery valve housing across the line of flow liquefied propellant and liquid aerosol solution from the storage compartment to the delivery port, and impeding flow of liquefied propellant to the delivery port in all orientations of the container.