GB2528284A

GB2528284A - Spray device

Info

Publication number: GB2528284A
Application number: GB1412622.1A
Authority: GB
Inventors: Alain Bou; Laetitia Rouault; Colin Litten-Brown
Original assignee: Robert McBride Ltd
Current assignee: Robert McBride Ltd
Priority date: 2014-07-16
Filing date: 2014-07-16
Publication date: 2016-01-20
Also published as: GB201412622D0

Abstract

An aerosol valve has a housing 3 with a lower inlet 8 and a tap orifice 4. A valve stem with an inlet 2 and outlet joined by a passageway is movable so that the inlet 2 can selectively communicate with the housing 3. An actuator 5 is mounted on the valve stem with a discharge aperture communicating with the valve stem outlet via a passageway. The vapour phase tap orifice 4 has a narrowest diameter of 0.58 to 0.64 mm; the housing inlet 8 has a narrowest diameter of 0.62 to 0.66 mm; the valve stem passageway inlet 2 has a narrowest diameter of 0.46 to 0.50 mm; and the actuator outlet 7 has a narrowest diameter of 0.49 to 0.53 mm. The aerosol mixture comprises 70 to 85% by weight of the propellant based on the total weight of said mixture. Certain subranges of these ranges are preferable. The propellant can be butane, propane and/or isobutene. The container may be 100ml.

Description

SPRAY DEVICE

Field of the invention

The present invention relates to the use of pressurised dispensing systems for the delivery of liquid formulations in which there are one or more active chemical components which on dispensing have specific topical effects for the prevention of perspiration or the chemical masking or binding of malodour chemicals.

Furthermore this invention relates to a combination of formulation and dispensing apparatus with specific characteristics for the delivery of precise and pre-determined amounts of chemical active material.

Pressurised dispensing systems comprising a container, which may be metal, plastic or glass to which is crimped a valve are well known and such systems are regularly used to dispense a variety of formulation types. Typically, such systems would dispense a liquid formulation by means of a propellant which may either be a volatile hydrocarbon or a compressed inert gas such as nitrogen or compressed air.

On such a dispensing system the container, typically steel or aluminium and less commonly plastic or glass contains the liquid formulation to be dispensed and also the propellant.

The valve is crimped onto the container in such a way that it cannot be easily removed and the only means of egress of the liquid formulation is via the valve mechanism.

Valves may be constructed in a variety of ways depending on the nature of the propellant, the liquid formulation to be dispensed and whether the dispenser is to be used in an upright or inverted orientation but in its basic form the valve is constructed of a valve cup with a lower hollow central plastic housing from the base of which extends a dip-tube into the liquid formulation to be dispensed.

The valve has a vertical narrow tube or hollow stem which is sprung-loaded and depression of the stem in a tilted or vertical downward direction opens the valve and allows for the release of liquid formulation and propellant.

Variation of the internal structure of the valve can be used to modify the discharge rate of a given combination of liquid formulation and propellant.

Equally, for the same valve modification of the physical properties of the liquid formulation e.g. viscosity, surface tension and ratio of formulation to propellant can be used to modify the discharge rate on actuation of the valve.

Typically such dispensing systems would also have an actuator which comprises a separate component, typically fashioned out of plastic, which attaches to the valve stem in its simplest form or sometimes is incorporated into a larger structure that fits over the valve cup or the entire top end of the dispensing system.

While varying in overall design the function of the actuator is to provide the user with a means of activating the valve and releasing the liquid formulation. In its simplest form the actuator would comprise a plastic button that attaches to the valve stem and comprises a central channel which locates with the central channel of the valve stem.

On actuation of the product the liquid formulation passes up the valve stem and enters the central channel of the actuator. Typically this channel is constructed in such a way that it turns through an angle of 9OC (the angle may vary depending on the intended discharge properties of the device) and emerges horizontally from the side of the actuator.

Such a device allows the user to depress the top surface of the actuator with a finger and often the top surface has a moulded feature or design intended to accommodate this usage.

The exit orifice of the actuator is often fitted with an insert in which the diameter of the orifice is restricted and such inserts can be changed for the same basic design of actuator body to modify the dispensing properties of the liquid formulation.

Such inserts can be used to not only modify the discharge rate but also the particle size into which the liquid formulation is broken on discharge. Depending on the usage and the nature of the formulation being dispensed it is advantageous to have larger or smaller droplet sizes dispensed from the device.

There are many sizes of container available and the internal volume can range from anything between approximately 1 OmI -1 000mI but for each product application a much narrower range of can sizes has evolved.

Typically in applications where a hydrocarbon propellant is required the ratio of liquid formulation to propellant has been developed in such a way as to result in a particular rate of delivery of the key active ingredient in the liquid formulation which has in turn resulted in performance expectations by the user with respect to this active ingredient.

Recently, concerns over raw material costs and the environmental impact of hydrocarbon propellants have made it desirable to reduce the size of the container and the amount of propellant but at the same time to maintain the performance expectations of the active ingredients and the same amount of usage as delivered by a standard size device but from a smaller unit.

Maintaining the same ratio of propellant to liquid formulation would result in less active material in the can so a more rapid rate of container evacuation.

What is needed is a specific combination of formulation and valve specification that can provide the same rate of active material delivery and the same total discharge time of the device but from a significantly smaller volume container with a lower ratio of propellant to liquid formulation.

Specifically, there is a requirement for the dispensing of topical preparations for the prevention of perspiration and the chemical masking or binding of malodour chemicals from a reduced volume dispenser that has the same level of performance as that achieved from a standard-sized container.

Summary of the Invention:

According to a first aspect of the present invention there is provided an aerosol spray device comprising a container holding a mixture comprising a liquid formulation to be dispensed by the device and a propellant pressurising the container, the device further comprising an aerosol valve assembly operation whereof effects dispense of the liquid as an aerosol, wherein: (i) the aerosol valve assembly comprises: (a) a housing located in a headspace of the container and having a housing inlet provided in the lower region of the housing, and further having a vapour phase tap orifice in the wall of the housing, (b) a valve stem having a valve stem passageway having a passageway inlet and a passageway outlet, said valve stem being moveable between a non-dispensing position and a dispensing position in which the passageway inlet communicates with the interior of the housing, and (c) an actuator mounted on the outlet end of the valve stem passage for effecting said movement of the valve stem, the actuator having a conduit in communication with the valve stem passageway and having an outlet configured for discharge of the mixture from the container to the ambient atmosphere, (H) the mixture comprises 70 to 85% by weight of the propellant based on the total weight of said mixture, and (Hi) at their narrowmost, the vapour phase tap orifice, housing inlet, stem orifice and actuator outlet have the following diameters: vapour phase tap orifice 0.58 to 0.64 mm; housing inlet 0.62 to 0.66 mm; valve stem passageway inlet 0.46 to 0.50 mm; and actuator outlet 0.49 to 0.53 mm.

At its narrowmost, the housing inlet of the aerosol spray device preferably has a diameter of 0.63 to 0.65 mm, more preferably about 0.64 mm. At its narrowmost, the actuator outlet of the aerosol spray device preferably has a diameter of 0.50 to 0.52 mm, more preferably about 0.51 mm. At its narrowmost, the valve stem passageway inlet preferably has a diameter of about 0.46 mm. At its narrowmost, the vapour phase tap orifice preferably has a diameter of about 0.64 mm. The housing inlet, actuator outlet, valve stem passageway inlet and/or vapour phase tap may individually be of uniform or non-uniform cross-section. If of uniform cross-section, they will be of the respective indicated diameter along their full length. If of non-uniform cross-section, then a portion (but not the whole) of their length will have the respective narrowmost diameter.

The mixture in the aerosol spray device preferably comprises 75 to 85%, more preferably 80% to 82%, and most preferably about 80% by weight of the propellant based on the total weight of said mixture. The propellant preferably comprises butane, propane, isobutene, or mixtures thereof.

The liquid formulation to be dispensed by the spray device preferably comprises any of the following components, individually or in combination. Preferred levels of incorporation of such components are also indicated below, the levels representing the preferred weight of incorporation of the respective component based on the total weight of the mixture: Component: Preferred level: Most preferred level: Cyclomethicone 7.0-12.0%; 9.0-9.3%; Disteardimonium hectorite 0.35-0.4%; 0.35-0.4%; Propylene carbonate up to 0.40%; 0.35-0.40; Triethyl citrate 1.5-3.0%; 1.5-2.0; Aluminium chlorohydrate 3.5%-6.0%; 4.5-5.0%; C12-C15 alkyl benzoate 0.1-1.5%; 0.9-1.0%; Perfume up to 3.0%; 1.3-1.8%.

Any of the aforementioned components of the liquid formulation may be encapsulated, if desired.

The volume of the container is preferably up to 250 ml, more preferably up to ml, even more preferably up to 150 ml, still more preferably up to 125 ml, and most preferably up to 100 ml.

The present invention finds particular utility in reduced volume" devices in which the container volume may be up to 150 ml (e.g. up to up to 125 ml or up to ml), yet contains the same quantity of liquid formulation to be dispensed by the device as compared with larger volume devices. The specific combination of propellant and valve specification enable such reduced volume devices to give the same rate of delivery of active material and the same total container evacuation rate as compared with their larger volume equivalents, despite having a reduced volume.

According to a second aspect of the present invention there is provided an aerosol valve assembly for use in the spray device according to the first aspect of the present invention.

Table 1 below shows a standard formulation including the ratio of liquid formulation to propellant for the prevention of perspiration and the chemical masking or binding of malodour chemicals and the expected discharge rate in grams per second (gls) and total container evacuation rate n seconds (s) that results in a specific delivery rate of the active material from the device.

In the device below the volume of the container is 200m1 and this will be taken as being the standard size for such a product. The construction of the valve for such a device would in this case have been specifically developed for the discharge characteristics quoted.

In this example the main active ingredients are the triethyl citrate and the aluminium chlorohydrate and the objective of the invention would be to have the same amounts of both materials and the same overall amount of liquid formulation in a smaller sized container and thus less propellant. The discharge rate would thus have to be modified to ensure the same rate of delivery of active ingredients.

Table 1: Formulation for use in standard volume (200m1) container Material Function Fercentage Mass per in container 200m1 container (g) Cyclomethicone Solvent! solublising agent. 5.400 6.372 Disteardimonium hectorite Stabilising agent 0.100 0.118 Triethyl citrate Deodorant 1.000 1.180 Aluminium chlorohydrate Anti-perspirant 2.500 2.950 Perfume Fragrance 0.500 0.590 C12-C15 alkyl benzoate Emollient 0.500 0.590 Liquid tormulation subtotal 10.000 11.800 Butane/propane!isobutane Propellant 90.000 106.200 TOTAL 100.000 118.000 Table 2 below shows a formulation for use in a lOOmI volume container in which the total amount of liquid formulation is the same as that in the formulation disclosed in Table I but the level of propellant has been lowered.

Table 2: Formulation for use in reduced volume (100m1) container Material Function Fercentage Mass per in container lOOmI container (g) Cyclomethicone Solvent / solublising agent. 9.120 5.655 Disteardimonium hectorite Stabilising agent 0.380 0.235 Propylene carbonate Solvent / activator for 0.380 0.235 stabilising agent Triethyl citrate Deodorant 1.900 1.178 Aluminium chlorohydrate Anti-persperant 4.750 2.945 Perfume Fragrance 1.330 0.825 Encapsulated perfume Delayed-release fragrance 0.190 0.118 C12-C15 alkyl benzoate Emollient 0.950 0.589 Liquid tormulation subtotal 19.000 11.780 Butane/propane/isobutane Propellant 81.000 50.220 TOTAL 100.000 62.000 In this formulation there is approximately halt of the mass of propellant as used in the 200m1 can and therefore the ratio of liquid formulation to propellant is different as for the formulation in Table 1. The total mass of the two main active materials is the same in the formulation shown in Table 2 as for the formulation shown in Table 1.

It is recognised that the tormulation could optionally contain natural plant extracts, vitamins or other materials to deliver specific functionality from the formulation.

The invention will now be further described, by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is an schematic sectional drawing of an embodiment of aerosol spray device according to the present invention as seen from a side thereof; and Fig. 2 is a further schematic sectional drawing ot the aerosol spray device shown in Fig. 1 as shown in perspective view.

Figures 1 and 2 below show stylised (not to scale) cross sections of a typical valve to show the key features.

In order to dispense the desired level of formulation there are a number of parameters within the valve that can be changed. The important dimensons that can be altered to modify the discharge rate are the diameter of the hole in the valve stem and the diameter of the vapour phase tap.

In addition to the valve the discharge rate can be modified by means of an insert at the end of the actuator. This insert is designed to restrict the orifice of the actuator or device attached to the valve stem to re-direct the discharge from the aerosol.

In Figures 1 and 2, the valve stem 1 has a valve stem passageway inlet 2 which forms the first critical dimension and the narrowmost diameter of which can be modified to alter the discharge rate. The housing 3 has a vapour phase tap orifice 4 which can also be modified in its narrowmost diameter to alter the discharge rate. Attached to the valve stem 1 is an actuator 5 with an insert 6, the actuator outlet 7 which can also be varied in its narrowmost diameter to modify the discharge rate. A final means of controlling the discharge rate is by the narrowmost diameter 8 in the inlet of the housing 3 leading to the dip tube.

In the present invention the desired range of dimensions of the valve stem passageway inlet at its narrowmost is 0.46-0.50mm with a preferred diameter of 0.46mm. The desired range of dimensions for the vapour phase tap at its narrowmost diameter is 0.58-0.64mm with a preferred diameter of 0.64. The preferred diameter of the actuator outlet at its narrowmost is 0.51 mm.

In a typical standard valve the hole in the valve stem would be in excess of 0.51mm at its narrowmost and the vapour phase tap in excess of 0.8mm at its narrowmost.

Thus, in order to provide a similar rate of delivery of active material and a similar total discharge rate of a concentrated aerosol compared to the equivalent standard one, in this case a lOOmI concentrated aerosol compared to a standard 200m1 aerosol what is required is both the combination of the formulation as described in Table 2 and the specific valve specifications as described above.

It has surprisingly been found that with a combination of this formula and valve specification that during use the aerosol will deliver the same amount of active material per second as the standard aerosol equivalent and also the total discharge rate of the concentrated aerosol is equivalent to the standard size aerosol but in a form that requires a much smaller aerosol container and less propellant.

APPENDIX: Embodments of the invention will now be described in the following paragraphs.

1. A combination of concentrated formulation and valve specification for the delivery of topical formulations in which the formulation consists of between 7.0- 12.0% cyclomethicone, 0.35-0.4% disteardimonium hectorite, 0.0-0.40% propylene carbonate, 1.5-3.0% triethyl citrate, 3.5%-6.0% aluminium chlorohydrate, 0.1-1.5% 012-015 alkyl benzoate and 0.0-3.0% perfume of which any proportion may be encapsulated, the formulation is used at a ratio of 10-30% formulation to 70-90% butane/propane/isobutane propellant, the valve has a stem orifice diameter of 0.46-0.50mm, a vapour phase tap diameter of 0.58-0.64mm and a restricted entrance housing of 0.64mm with an actuator insert diameter of 0.51 mm.

2. A formulation as in embodiment 1 where the preferred ranges are between 9.0- 9.3% cyclomethicone, 0.35-0.4% disteardimonium hectorite, 0.35-0.40 % propylene carbonate, 1.5-2.0% triethyl citrate, 4.5-5.0% aluminium chlorohydrate, 0.9-1.0% C12-C15 alkyl benzoate and 1.3-1.8% perfume with a preferred range of 1.3-1.8% of which any proportion may be encapsulated.

3. An aerosol device in which the preferred ratio of formulation to propellant is 18- 20% formulation to 80-82% propellant.

4. A combination of concentrated formulation and valve specification for the delivery of topical formulations in which the formulation consists of between 7.0- 12.0% cyclomethicone with a preferred range of 9.0-9.3%, 0.35-0.4% disteardimonium hectorite, 0.0-0.40% propylene carbonate with a preferred range of 0.35-0.40, 1.5-3.0% triethyl citrate with a preferred range of 1.5-2.0, 3.5%-6.0% aluminium chlorohydrate with a preferred range of 4.5-5.0%, 0.1- 1.5% 012-Cl 5 alkyl benzoate with a preferred range of 0.9-1.0% and 0.0-3.0% perfume with a preferred range of 1.3-1.8% of which any proportion may be encapsulated, the formulation is used at a ratio of 10-30% formulation to 70- 90% butane/propane/isobutane propellant with a preferred range of 18-20% formulation to 80-82% propellant, the valve has a stem orifice diameter of 0.46- 0.50mm, a vapour phase tap diameter of 0.58-0.64mm and a restricted entrance housing of 0.64mm with an actuator insert diameter of 0.51 mm.

Claims

CLAIMS: 1. An aerosol spray device comprising a container holding a mixture comprising a liquid formulation to be dispensed by the device and a propellant pressurising the container, the device further comprising an aerosol valve assembly operation whereof effects dispense of the liquid as an aerosol, wherein: (i) the aerosol valve assembly comprises: (a) a housing located in a headspace of the container and having a housing inlet provided in the lower region of the housing, and further having a vapour phase tap orifice in the wall of the housing, (b) a valve stem having a valve stem passageway having a passageway inlet and a passageway outlet, said valve stem being moveable between a non-dispensing position and a dispensing position in which the passageway inlet communicates with the interior of the housing, and (c) an actuator mounted on the outlet end of the valve stem passage for effecting said movement of the valve stem, the actuator having a conduit in communication with the valve stem passageway and having an outlet configured for discharge of the mixture from the container to the ambient atmosphere, (H) the mixture comprises 70 to 85% by weight of the propellant based on the total weight of said mixture, and (Hi) at their narrowmost, the vapour phase tap orifice, housing inlet, stem orifice and actuator outlet have the following diameters: vapour phase tap orifice 0.58 to 0.64 mm; housing inlet 0.62 to 0.66 mm; valve stem passageway inlet 0.46 to 0.50 mm; and actuator outlet 0.49 to 0.53 mm.
2. The aerosol spray device according to claim 1 wherein, at its narrowmost, the housing inlet has a diameter a! 0.63 to 0.65 mm.
3. The aerosol spray device according to claim 2 wherein, at its narrowmost, the housing inlet has a diameter of about 0.64 mm.
4. The aerosol spray device according to any preceding claim wherein, at its narrowmost, the actuator outlet has a diameter of 0.50 to 0.52 mm.
5. The aerosol spray device according to claim 4 wherein, at its narrowmost, the actuator outlet has a diameter of about 0.51 mm.
6. The aerosol spray device according to any preceding claim wherein, at its narrowmost, the valve stem passageway inlet has a diameter of about 0.46 mm.
7. The aerosol spray device according to any preceding claim wherein, at its narrowmost, the vapour phase tap orifice has a diameter of about 0.64 mm.
8. The aerosol spray device according to any preceding claim wherein the mixture comprises 75 to 85% by weight of the propellant based on the total weight of said mixture.
9. The aerosol spray device according to any preceding claim wherein the mixture comprises 80% to 82% by weight of the propellant based on the total weight of said mixture.
10. The aerosol spray device according to any preceding claim wherein the mixture comprises about 80% by weight of the propellant based on the total weight of said mixture.
11. The aerosol spray device according to any preceding claim wherein the propellant comprises butane, propane, isobutene or mixtures thereof.
12. The aerosol spray device according to any preceding claim wherein the volume of the container is up to 250 ml.
13. The aerosol spray device according to claim 12 wherein the volume of the container is up to 175 ml.
14. The aerosol spray device according to claim 13 wherein the volume of the container is up to 150 ml.
15. The aerosol spray device according to claim 14 wherein the volume of the container is up to 125 ml.
16. The aerosol spray device according to claim 15 wherein the volume of the container is up to 100 ml.
17. An aerosol spray device substantially as hereinbefore described with reference to Figures 1 and 2.
18. An aerosol valve assembly for use in the spray device according to any preceding claim.