GB2036064A

GB2036064A - Process for the manufacture of a dimethyl ether preparation which can be safely transported, and its use as a propellant filling in aerosol cans

Info

Publication number: GB2036064A
Application number: GB7939578A
Authority: GB
Original assignee: Hans Schwarzkopf and Henkel GmbH
Current assignee: Hans Schwarzkopf and Henkel GmbH
Priority date: 1978-11-15
Filing date: 1979-11-15
Publication date: 1980-06-25
Also published as: DE2849591A1; GB2036064B; DE2849591C2; FR2457818A1; JPS5573775A; NL7908278A; IT7927324A0; IT1127236B; FR2441654A1; BE880035A

Abstract

Process for the manufacture of a dimethyl ether preparation which can be safely transported, characterised in that a) dimethyl ether is mixed with water under pressure to give a homogeneous solution, or that b) dimethyl ether is mixed with methylene chloride and/or 1,1,1 - trichloroethane under pressure to give a homogeneous solution and a mixture of a) or b) is used, or the two mixtures a) and b) are used, as a propellant for the production of carrier mixtures in aerosol preparations. t

Description

SPECIFICATION Process for the manufacture of a dimethyl ether preparation which can be safely transported, and its use as a propellant filling in aerosol cans.

The invention relates to a process for the manufacture of a dimethyl ether preparation which can be safely transported, and to its use as a propellant filling in aerosol cans.

As is known, dimethyl ether boiis at -250C and represents a colourless, inflammable gas of etherlike odour, 37 litres of gaseous dimethyl ether being solubie in one litre of water at 1 80C. It is also known that strict official regulations have to be observed in the transport, storage and handling of dimethyl ether.

It is an aim of the present invention to provide a process for the manufacture of a dimethyl ether preparation which can be safely transported.

Other desirable features are as follows:- 1. The dimethyl ether preparation obtained by the process should be suitable as a carrier mixture and propellant for the production of aerosol preparations.

2. In the manufacture and in the use of the dimethyl ether preparation in pressurised containers, the preparation should be present as a stable homogeneous solution -- that is to say as a single-phase system - so that, in use, the spray is always dispensed in the same composition.

3. The dimethyl ether preparation should contain the greatest possible proportion of non inflammable constituents so that, as far as possible, transport, storage and use can be free from accident risk and the environment cannot be polluted.

4. When the dimethyl ether preparation is used for formulating aerosol preparations, these should be free from chlorofluorinated hydrocarbons and hydrocarbon propellant gases.

5. The drying times and the spray properties of aerosol preparations, which are produced with the use of the dimethyl ether preparation, should, at least when a specially adapted pressure valve is used, largely correspond to those to which the users have become accustomed when using the known aerosol preparations based on fluorochlorohydrocarbon propellant gases.

6. In the conventional methods for measuring a flame jet, the dimethyl ether preparation should not give a flame jet and should not contain more than 45 per cent by weight of inflammable constituents.

Japanese Laid-open Application Sho 46-28,440 describes a single-phase aerosol composition of (a) 1 to 5% by weight of a pesticide, (b) 0 to 20% by weight of a short-chain alcohol having 2 to 3 carbon atoms, ethylene glycol monoalkyl ether having 1 to 4 carbon atoms in the alkyl radical or diethylene glycol monoalkyl ether having 1 to 4 carbon atoms in the alkyl radical, (c) 1.5 to 15% by weight of a polyoxyethylene alkylaryl ether having 8 to 18 polyoxyethylene ethers of higher alcohols, having 6 to 15 polyoxyethylene radicals, (d) 20 to 50% by weight of water and (e) 20 to 50% by weight of dimethyl ether. The drying times of the sprayed aerosol are very long when compared with the drying times of comparable aerosols based on fluorohydrocarbons as propellant gases.In Japanese Laid-open Application Sho 47-22,599, an aerosol of a styling dispersion for hair care is described, which aerosol contains a mixture which, for dispersing an appropriate quantity of a styling agent in water, was prepared by dispersing an organic amine, wetting agent, thiourea or urea as well as perfume in the aqueous solution of a cationic resin, contains 20 to 50% by weight of dimethyl ether, relative to the dispersion, as an additive, and has been filled into the spray can and sealed. The disadvantage of this aerosol preparation is that it isa dispersion and not a clear solution. In the abovementioned Japanese Patent descriptions, dimethyl ether is injected as such into the aerosol cans -- dimethyl ether/water mixtures have not been described or suggested in these prior descriptions.

The subject of the invention is a process for the manufacture of a dimethyl ether preparation which can be safely transported, characterised in that a) dimethyl ether is mixed with water under pressure to give a homogeneous solution, or that b) dimethyl ether is mixed with methylene chloride and/or 1,1,1 -trichloroethane under pressure to give a homogeneous solution and a mixture of a) or b) is used, or the two mixtures a) and b) are used, as a propellant for the production of carrier mixtures in aerosol preparations.

A further embodiment of the process according to a) is characterised in that about 6.0 to about 32.0% by weight of dimethyl ether and about 68.0 to about 94% by weight of water are used, and the % by weight of the two components must add up to 1 0% by weight.

A special embodiment of the process according to a) is characterised in that about 27.0 to about 32.0% by weight of dimethyl ether and about 68.0 to about 73.0% by weight of water are used, and the % by weight of the two components must add up to 100% by weight.

A further embodiment of the process according to b) is characterised in that about 10.0 to about 45.0% by weight of dimethyl ether and about 55.0 to about 90.0% by weight of methylene chloride and/or 1,1,1 -trichloroethane are used, and the % by weight of the components must add up to 100% by weight.

A further embodiment of the process according to a) or b) is characterised in that the mixture a) or b) is prepared in the presence of up to about 1 1% by weight of ethanol and/or n-propanol and/or isopropanol, the percentage by weight data relating to the weight of the mixture a) or the mixture b) respectively.

A further special embodiment of the process according to a) is characterised in that about 10.0 to about 40.0% by weight of dimethyl ether, about 15.0 to 5.0% by weight of ethyl alcohol and/or iso-propanol and/or n-propanol and about 85.0 to about 45.0% by weight of water are used, and the % by weight of the components must add up to 100% by weight.

Afurther special embodiment of the process according to b) is characterised in that about 10.0 to about 40.0% by weight of dimethyl ether, about 1 5.0 to about 5.0% by weight of ethyl alcohol and/or iso-propanol and/or n-propanol and about 85.0 to about 45.0% by weight of methylene chloride and/or 1,1 1 -trichloroethane are used, and the % by weight of the components must add up to 100% by weight.

The subject of the invention also includes the use of the dimethyl ether mixtures, obtainable in accordance with the process of the invention, as a propellant in pressurised carrier mixtures for aerosol prepartions or in aerosol preparations.

In a first special application, one of the mixtures or several of the mixtures are used for the production of aerosol preparations which are present as pressurised aerosol preparations formulated as a mixture of propellant gas and organic solvents as the propellant, active ingredients and solvents for the active ingredients, which mixture is to be sprayed, for example, as a cosmetic spray, room spray or medicinal spray, the mixture being present as a homogeneous solution which comprises at least 50% by weight, preferably at least 55% by weight, of non-inflammable constituents -- relative to the total weight of the mixture -- and contains carbon dioxide and dimethyl ether as the propellant and contains at least water, carbon dioxide, methylene chloride and/or 1,1,1-trichloroethane as the non-inflammable constituents.

In a second special application, one of the mixtures is used for the production of carrier mixtures for aerosol preparations and the production of aerosol preparations from the former, which are present as a pressurised carrier mixture for aerosol preparations of a self-propelling spray system for use as a universal spray based on the active ingredients to be applied, organic solvents, water and propellants in a spray container, and the carrier mixture is present as a homogeneous solution which contains 70.0- 50.1 per cent by weight of water, 38.5-28.7 per cent by weight of dimethyl ether, 0.5-1 0.0 per cent by weight of iso-propanol and/or ethanol and/or n-propanol and 1.4-0.8 per cent by weight of carbon dioxide, and the percentage by weight data must add up to 100 per cent by weight.

The mixtures obtainable according to the process a) orb) of the invention are advantageously already produced at the company manufacturing the dimethyl ether, by adding water and, if appropriate, ethanol and/or iso-propanol and/or n-propanol to the dimethyl ether, or by adding methylene chloride and/or trichloroethane and, if appropriate, ethanol and/or iso-propanol and/or n-propanol to the dimethyl ether. The transport and storage of dimethyl ether mixtures of this type are substantially safer, as a result of which substantial technical simplifications are permissible in the transport and storage installations and in the production of the aerosol preparations, so that mixtures manufactured according to the invention lead to considerable technical advances in various directions.

The dimethyl ether mixtures manufactured according to the process of the invention can be processed to give carrier mixtures for aerosol preparations of the most diverse types, additional propellants, for example carbon dioxide, also being used if appropriate. If the aerosol preparations manufactured in this way are to be in the form of a wet spray, the conventional spray valves for spray cans can be used.

If, however, the drying times and the spray properties of aerosol preparations which are manufactured with the use of the dimethyl ether preparations obtainable according to the present process are to correspond to the known aerosol preparations based on fluorochlorohydrocarbon propellants, it is advantgeous to use a specially adapted pressure valve for this purpose.

The invention also relates to the use of the homogeneous solution, prepared in accordance with one of the above embodiments of the process, as a propellant filling in aerosol cans which, formulated as a medicinal spray, cosmetic spray or room spray, are provided with a self-closing spray valve, as a super-fine atomisation valve, for pressure containers which contain solutions of a gas and/or liquid, having a valve stem which, inside a valve housing, is axially movable in the direction of opening against the action of a closing compression spring which is backed up by the valve housing, an axial outlet channel in the valve stem being connected to the interior of the pressure container by means of a radial outlet channel which ends in an annular groove in the valve stem, the radial outlet channel thereof being sealed, in the closed position, by an elastic annular grommet, the cylindrical internal circumference of which engages in the annular groove with a radial bias and the external edge of which is not clamped between the valve housing and the dome of the cap, the shoulder, which faces the container, of the annular groove, when in the closed position, being in tight contact with the grommet under the action of the closing compression spring, whilst the forces which are exerted by the annular groove in the valve stem on the circumferential sections, which are above the neutral bending zone, of the hole in the grommet are composed of a force component which is in each case radial to the valve stem and of a force component which is parallel to the axis, which components are greatest at the upper edge, and, when the valve is closed, the forces which are exerted by the annular groove in the valve stem on the circumferential sections, which are below the neutral bending zone, of the hole in the grommet are also composed of a force component which is in each case radial to the valve stem and a force component which is parallel to the axis, these force components being greatest at the lower edge of the hole of the grommet, and which aerosol can is in a form adapted to the specific intended use by combining the embodiments a, b, c, d, e and fin such a way that a) a resistor in the shape of a body with a cylindrical bore is located in compression in the axial outlet channel of the valve stem part and, in the centrally arranged restricting channel, a bridge member is provided which is located in the centre of the restrictor and contains the passage orifice, b) the turbulent-spray head with the inserted turbulencejet is firmly but releasably attached and The spray head has a cylindrical jet-receiving plug having two surfaces which are parallel to the axis and, as viewed from the jet orifice, are vertically arranged, c) the jet-receiving plug carries the forced-on turbulence jet, four raised webs of which rest on the end face of the jet-receiving plug d) the four webs around the jet orifice on the inside of the turbulence jet form an approximately cylindrical turbulence chamber and the webs free the inlet channels which are in a location tangential to the circular jet orifice, e) a cylindrical recess is located on the outer surface of the turbulence jet, concentrically to the jet orifice, and f) the turbulent-spray head contains an approximately eccentrically arranged, tapering chamber which communicates with the annular channel and merges into the receiving opening which is located underneath and is to receive the valve stem part.

In the drawings, namely Figures 1 to 13, the aerosol can is explained by reference to the illustrative embodiments represented, in which: Figure 1 shows a spray valve in the closed state, in a vertical longitudinal section, Figure 2 shows the spray valve according to Figure 1 in the opened state, Figure 3 shows another embodiment of a spray valve in a vertical longitudinal section, the spray valve being in the opened state in the left-hand half of the longitudinal section and being in the closed state in the right-hand half of the longitudinal section;; Figure 4 shows a restrictor in a vertical longitudinal section, Figure 5 shows a vertical longitudinal section of a turbulent-spray head, Figure 6 shows a vertical longitudinal section through the turbulent-spray head shown in Figure 5 along the cut A-B, Figure 7 shows a sectional drawing through the jet-receiving plug of the turbulent-spray head, with the jet inserted, Figure 8 shows a view of the interna l bottom of the inserted jet, Figure 9 shows a vertical longitudinal section through the inserted jet partially shown in Figure 8, Figure 10 shows another embodiment of a spray valve in longitudinal section, Figure 11 is cut-out from Figure 10 on an enlarged scale, Figure 12 shows a modification of the embodiment according to Figure 10 and Figure 1 and Figure 13 shows a longitudinal section of an aerosol spray can which contains a spray valve of the type described in Figures 1 to 12 and which is filled with an aerosol preparation.

Figures 1 and 2 illustrate a self-closing spray valve for a pressure container, which is not shown, containing an aerosol preparation which comprises a solution ofgas-liquid, for example liquefied propellant gas, which spray valve essentially consists of a housing 1, a valve stem 2, an elastic grommet 3 and a closing spring 4. The valve stem 2 is movable in the direction of opening against the action of the closing compression spring 4 and the elasticity of the grommet. The edge of the hole of the grommet 3 is inserted with a radial bias in an annular groove 5 of the valve stem the greatest width of the groove being about one third greater than the thickness of the grommet.In the closed position of the,valve, in Figure 1 , the forces which are simultanousiy exerted by the annular groove 5 in the valve stem 2 on the circumferential sections, which are above and below the neutral bending zone, of the hole in the grommet 3 are composed of a force component which is in each case approximately radial to the valve stem 2 and of a force component which is approximately parallel to the axis. Due to the profiled shape of the annular groove, the two force components are here greatest at the upper and lower edge of the hole of the grommet. In the iliustrative embodiment in Figures 1 and 2, this is achieved by an annular groove which, in transverse profile, has approximately the shape of a circular arc.The profile of the annular groove can, however, also have the shape of a catenary or of a parabola or the like or it can also be shaped in the form of a V. The essential point is merely that, in the zones, facing the container and facing away from the container, of the edge of the hole in the grommet, there is a particularly high specific surface pressure, by means of which an especially good sealing effect is achieved both at the upper inner edge and at the lower inner edge. As a function of the radial bias and the nature of the material for the grommet, an annular space 6 can be formed between the bottom of the annular groove 5 and the cylindrical inner surface of the hole in the grommet.However, even if a highly elastic material, completely filling the groove, is used for the grommet, the intended purpose of an increased specific surface pressure is fulfilled by the decomposition of forces, provided according to the invention, by means of the annular groove at both the upper and the lower edge of the hole.

The annular groove 5 covers at least one radial outlet channel 7 which, in the direction of flow of the solution of gas/liquid, ends in an axial outlet channel 8 of the valve stem 2, which axial outlet channel starts in the zone of the radial outlet channel 7 and is open only towards the outer end.

A turbulent-spray head 10, consiting of plastic, with an inserted turbulence jet 37 is firmly but releasably attached to the valve stem part 9 surrounding the axial outlet channel 8. The turbulent-spray head 10 consists -- as can be seen in particular from Figures 5 to 9 - of the spray head 12 (without jet) with a cylindrical jet-receiving plug 13 which has two surfaces 35 which are parallel to the axis and, as viewed from the jet orifice 36, are vertically arranged. The jet-receiving plug 13 carries the forced-on turbulence jet 37, four raised webs 38 of which rest on the end face 39 of the jet-receiving plug 13. The four webs 38 form an approximately cylindrical turbulence chamber 44 around the jet orifice 36 on the inside of the turbulence jet 37.The webs 38 mutually free the inlet channels 40 which are in a location tangential to the circular jet orifice 36. The webs 38 have a cylindrical outside which is interrupted by the inlet channels 40. A cylindrical recess 41 is located on the outer surface of the turbulence jet 37, concentrically to the jet orifice 36. The turbulent-spray head 10 contains a somewhat eccentrically arranged, tapering chamber 11 which communicates with the annular channel 42 and merges into the receiving opening 43 which is located underneath and is to receive the valve stem part 9. A restrictor 32, which is shown particularly clearly in Figure 4, in the shape of a cylindrical body with a bore is located in compression in the axial outlet channel 8 of the valve stem part 9. The centrally arranged restricting channel 33 is provided in a bridge member 31 located in the centre of the restrictor 32.The passage orifice 27 has a size of about 2.0 to 3.0 mm, preferably 2.5 mm. The diameter of the radial outlet channel 7 in the valve stem 2 can be about 0.2 to 0.3 mm, preferably 0.25 mm. The restricting channel 33 in the bridge member 31 has a length/diameter (1/d) ratio of 1.0 to 3.0, the diameter being of the order of magnitude of the radial outlet channel 7. The height of the bridge member 31 is approximately one tenth of the length of the restrictor32, the diameters of the inlet and outlet openings of the restrictor 32 being 0.5 mm to 1.0 mm, preferably 0.8 mm. The passage channel 45 between the jet-receiving plug 13 and the turbulence jet 37, which passage channel is formed by the surfaces 35 on the jet receiving plug 13 and the inner wall of the turbulence jet 37, has at its maximum point a width of 0.15 to 0.25 mm, preferably 0.20 mm.The length of this passage channel 45 is about 3.5 mm. The front annular channel 47 on the end face 39 of the jet-receiving plug 13 has an external diameter of about 4 mm and an internal diameter which is formed by the cylindrical outline of the webs 38. This internal diameter is 2 to 3 mm and the front annular channel 47 has a channel height which is equal to the web height and specifically is 0.2 to 0.3 mm preferably 0.25 mm. The inlet channels 40 are 0.1 5 to 0.30 mm wide and have the height of the webs 38. The turbulence chamber 44 has an approximately cylindrical diameter of 0.70 to 1.30 mm, preferably 0.90 mm. The height of the turbulence chamber 44 is equai to the height of the webs 38. The jet orifice 36 has a length/diameter (1/d)ratio of 0.3 to 1.0, preferably about 0.5, the diameter being 0.3 to 0.6, preferably 0.5 mm.The cylindrical recess 41 has a diameter of about 1 mm and a depth of 0.2 mm.

The outer valve stem part 9 surrounding the axial outlet channel 8 protrudes through a central opening 1 4 into the dome 1 5 of a container lid 1 6. The valve housing 1 is inserted in the dome and its end face, which is chamfered on the outside and faces the central opening 14 in the dome, firmly and tightly clamps the outer edge of the grommet against the inside of the dome by pressing the cylindrical part of the dome in under a part 17, of widened diameter, of the valve housing.

On the side of the annular surface 18, facing the container, an inner guide stem part 22 of the greatly reduced diameter is guided to be axially displaceable on guide jaws 23 provided within the valve housing 1. The guide jaws are joined to the inner wall and the bottom of the valve housing 1 and are shaped as relatively narrow ribs. Between them, they enciose interspaces which form connection channels 24 between the interior of the container and the interior of the valve housing.

The two ends of the closing compression spring 4 surrounding the guide stem part 22 are backed up by the end face of the annular surface 1 8, facing the container, on an annular shoulder 25 and by the end face 26 facing the annular shoulder, of the guide jaws 23 of the valve housing. In the zone of the outer end of the closing compression spring 4, bearing against the annular shoulder 25, the diameter of the inner guide shaft 22 of the valve cone is adapted over a small length approximately to the internal diameter of the closing compression spring, the external diameter of which corresponds approximately to that of the outer valve stem part 9. The main section of the inner guide stem part 22 has a smaller dimension than the internal diameter of the closing compression spring 4, in order to avoid friction between the parts which move relative to one another. Advantageously, the guide jaws 23 also possess, in the zone of their end face 26 facing the closing compression spring, projections which are not shown and surround the outside of the inner end of the closing spring and by means of which the end of the spring is fixed.

In the bottom, the valve housing 1 is provided with a passage orifice 27 which ends in a projection 28, pointing into the container, for a dip tube 29 pushed over the latter. The projection 28 can be provided with a tooth-shaped annular collar 30, by means of which a notch-like connection between the dip tube and the projection 28 is obtained.

The embodiment shown in Figure 3 is distinguished in that the upper edge of the valve housing 1 is formed obliquely, rising from the outside. The central opening 14 in the dome of the disc has an internal roll 34 located by beading. The outer valve stem part 2 is formed with a smaller diameter, compared with the valve stem 2.

The embodiments shown in Figures 10, 11 and 12 differ from the embodiment shown in Figures 1 and 2 in that the bottom 5a of the annular groove 5 in the valve stem 2 encloses an approximately right angle with the upper side wall 5b of the groove, facing away from the container and being approximately perpendicular to the main axis of the valve stem. On the side facing the container, the bottom 5a extends conically and radially downwards and outwards. It can be seen from the groove profile according to Figures 11 and 1 2 that the bottom extends cylindrically over approximately the upper third of the width of the groove and then has the shape of a downward circular arc.In place of a line in the form of an exact circular arc, the groove can also run out on the underside in the form of a different arcuate line. The essential point is that, in the zone of the edge 3a, facing the container, of the hole in the elastic grommet 3, a particularly great specific surface pressure is achieved in order to obtain a high sealing effect.

In the embodiment according to Figure 11, it is advantageous to place the radial passage channel 7 in the valve stem 2 likewise into the zone of the annular groove, exposed to the axial and radial force components. Accordingly, the distance between the centre line of the passage channel 7 and the lower line of intersection between the groove ending in the shape of an arc and the cylindrical shell surface of the section of the valve stem 2, located underneath, is about one fifth of the total width of the groove between the line Sc of intersection and the upper axial transverse shoulder 5b.In this way, the radial and axial force components, which are caused by the closing force of the compression spring 4 for the purpose of an increased surface pressure in the zone of the radial passage channel 7, are added to the radial bias, under which the grommet engages in the groove.

In the embodiment according to Figure 12, the valve stem 2 has, in order to determine its closing position accurately even if the grommet 3 is swollen, at least one radially projecting surface 46 immediately above its annular groove, which projecting surface bears, as a stop, against the inside of the dome 1 5, enclosing the valve housing 1, of a container lid 1 6. In this case, it would be advisable to place the radial passage channel 7 somewhat higher up since, due to the closing position being always exactly determined, the upper edge of the hole of the grommet 3 is in the vicinity of the upper axial transverse shoulder 5b.In order to ensure an accurately plane position of the grommet even in the zone of the edge of its hole, the edge 1 5a, delimiting the opening 1 4 for the valve stem 2, of the dome 1 5 of the container lid 1 6 is pressed upwards during the manufacture of the container lid by the height of the radial projection of the valve cone, forming the abutment surface 34.

In use, the turbulent-spray head 10 is pressed down. As a result, the radial outlet channel 7 which is sealed in the rest position by the elastic grommet 3 is lowered and connected to the free annular space. At the same time, the closing compression spring is compressed and tensioned. The medium which is to be sprayed is forced by the internal pressure in the can through the dip tube 29 and the passage orifice 27 through the connecting channels 24 into the free annular space 20 and flows through the radial outlet channel 7. The expansion in the axial outlet channel 8 of the valve stem 2 effects a formation of vapour, whereby the single-phase mixture is transformed into a two-phase mixture.While the flow proceeds through the restrictor 32, in particular through the restricting channel 33, the mixture is compressed and accelerated, as a result of which the droplet size of the mixture is made finer during the expansion after the restrictor and in the chamber space 11. The mixture which has already been worked into the form of droplets flows from the chamber 11 into the annular channel 42, is divided there into two streams axial to the jet-receiving plug 13 and reaches the inlet channels through the passage channels 45 via the front annular channel. The four inlet channels 40 in turn act as restrictors and at the same time cause a rotary flow of the mixture to be formed in the turbulence chamber. As a result of both the expansion into the turbulence chamber and the diffuser effect of the inlet channels 40, the droplet size of the two-phase mixture is repeatedly reduced.The jet orifice 36 effects a further restriction with a subsequent expansion. The rotation of the flow in the turbulence chamber continues on emergence from the jet orifice 36 and additionally effects a division of the droplets of the two-phase mixture after they have left the orifice. The decisive point for the form of the spray jet is the length/diameter (I/d) ratio of the jet orifice 36 and the geometry of the cylindrical recess 41 located in front thereof.

The first special use, already briefly indicated, of one of the mixtures or several of the mixtures which contain methylene chloride and/or 1,1,1 -trichloroethane as well as dimethyl ether and which are obtained according to the process of the invention, for the manufacture of aerosol preparations will now be described in more detail.

Possible organic solvents for the propellant gases to form the propellant and possible solvents for the active ingredients are acetone, ethyl methyl ketone, diethyl ether, dimethoxymethane, diethyl carbonate, ethyl alcohol, n-propanol, iso-propanol, methyl acetate, ethyl acetate, methoxyacetone, hydroxyacetone, methyl isopropyl ketone, diethyl ketone, diisopropyl ketone, dipropyl ketone, diacetone-alcohol, dichioroethylene, ethyl chloride, 1 , 1 -dichloroethane and 1-chlorobutane, individually or as a mixture.

In the sense of this invention, non-inflammable constituents are understood to be water, carbon dioxide, methylene chloride and/or 1,1,1-trichloroethane and those other constituents, for example active ingredients, which have an ignition temperature above 6000 C.

The preparations according to the invention can be formulated with cosmetic, hygienically or medically active constituents (active ingredients) and yield preparations for diverse purposes, such as, for example, as a cosmetic spray, room spray or medicinal spray.

The active constituents contained in the preparations can for example, be hair- care substances, hair-spray resin, antiperspirants, deodorants, bactericides, perfume, fungicides, plant extracts and/or organ extracts.

The propellant system used in the preparations according to the invention is based on the propellant gases carbon dioxide and dimethyl ether and on organic solvents as the propellant. The propellant system contains methylene chloride and/or 1,1,1-trichloroethane, as the materials which are soluble in the propellant, as well as water.

An embodiment of the aerosol preparation is characterised in that it contains 4 to 6 per cent by weight of carbon dioxide and 6 to 10 per cent by weight of dimethyl ether as the propellant gases, the percentages by weight being related to the total weight of the constituents filled in.

Another embodiment of the aerosol preparation is characterised in that it contains 12.9 to 1 8 per cent by weight of water, the percentages by weight being related to the total weight of the constituents filled in.

A further embodiment of the aerosol preparation is characterised in that it contains 32 to35 per cent by weight of methylene chloride and/or 1,1,1 trichloroethane, the perecentages by weight being related to the total weight of the constituents filled in.

A further embodiment of the aerosol preparation is characterised in that it contains 33 to 43 per cent by weight of organic solvents for propellant gases and active ingredients, the percentages by weight being related to the total weight of the constituents filled in and the pressure in the aerosol container being about 5 to 7 bars.

In a preferred embodiment, the aerosol preparation is characterised in that it contains 12.9 to 17.5 per cent by weight of water, 4 to 6 per cent by weight of carbon dioxide, 6 to 8 per cent by weight of dimethyl ether, 35 to 40 per cent by weight of organic solvent, 32 to 35 per cent by weight of methylene chloride and/or 1,1,1-trichloroethane and 0.5 to 3.1 per cent by weight of active ingredient, wherein the indicated percentages by weight must add up to 100 per cent by weight.

The nature and amount of required active ingredient, organic solvent for the propellant gases, solvent for the active ingredients, carbon dioxide, dimethyl ether, water as well as methylene chloride and/or 1,1 ,1-trichloroethane are, taking into account the intended use, qualitatively and quantitatively matched in a trial batch in such a way, taking into account the ranges of percentages by weight indicated above, that a homogeneous solution is formed as a single phase which can be sprayed perfectly to give a ready-to-use aerosol.

Taking into account the above rules for technical action, the following tolerance range was determined for a specific aerosol preparation according to the invention, which was present as a homogeneous solution ansd as single phase and which could be sprayed perfectly: 13.62 to 14.35 per cent by weight of water, 4.57 to 4.27 per cent by weight of carbon dioxide, 6.95 to 7.76 per cent by weight of dimethyl ether, 34.06 to 32.86 per cent by weight of iso-propanol and/or ethanol and/or n-propanol, 3.72 to 4.36 per cent by weight of acetone and/or methoxyacetone, 35.00 to 33.93 per cent by weight of methylene chloride and/or 1,1,1 -trichloroethane and 2.08 to 2.47 per cent by weight of active ingredients.

The percentage by weight data must here also be selected in such a way that their sum gives 1 00 per cent by weight. In aerosol preparations which were prepared according to the above most preferred embodiment, the content of non-inflammable constituents was 55.02 to 55.33 per cent by weight.

Compared with the state of the art according to German Offenlegungsschrift 2,705,872, Example 2, with a maximum of 40 per cent by weight of non-inflammable constituents, this means an advance by a major step-change. For this reason, the aerosol preparations according to the invention are used in transport, storage and application as a product of low accident risk for the intended purpose, so that it can be called a "safety aerosol preparation".

The most preferred embodiment, illustrated above, of the pressurised aerosol preparation is explained in more detail by Examples 1 to 5.

All the aerosol preparations which are described in Examples 1 to 5 are present as a homogeneous solution and as a single phase in the container. All the aerosol preparations according to Example 1 to 5 could readily be sprayed at 200C so that the entire content of the can was utilised in accordance with its purpose. The ready-to-use aerosol products according to Examples 1 to 5 have a pressure of about 5 to 7 bars after filling.

Further experimental investigations in the manner of spot checks have shown that, in the aerosol preparation according to the invention of approximately the composition 13.62 to 14.35 per cent by weight of water, 4.57 to 4.27 per cent by weight of carbon dioxide, 6.95 to 7.76 per cent by weight of dimethyl ether, 37.78 to 37.22 per cent by weight of organic solvents, 35.00 to 33.93 per cent by weight nf methylene chloride and/or 1,1,1 -trichloroethane and 2.08 two 2.47 per cent by weight of active ingredients, wherein the percentage by weight data must add up to 100% by weight, taking into account the intended purpose when testing trial batches in which a homogeneous solution is formed as the single phase and which could be sprayed perfectly, the following organir solvents, by way of example, can also be used individually up to the following quantities: 3.724.36 per cent by weight of acetone, up to 4.36 per cent by weight of ethyl acetate only in combination with 1,1,1 -trichloroethene, 1.98-2.37 per cent by weight of diacetone-alcohol, up to 4.36 per cent by weight of dimethoxymethane only in combination with 1,1,1 -trichloroethane, 3.72-4.36 per cent by weight of hydroxyacetone, 3.72-4.36 per cent by weight of methoxyacetone, up to 4.36 per cent by weight of methyl acetate only in combination with 1,1,1 -trichloroethane, up to 4.36 per cent by weight of methyl ethyl ketone only in combination with 1 ,1 ,1 -trichloroethane, and up to 4.36 per cent by weight of methyl isopropyl ketone only in combination with 1,1,1 trichloroethane.

Further spot check tests have shown that mixtures of hydroxyacetone and methoxyacetone can also be useful in the range from 3.72 to 4.36 per cent by weight.

EXAMPLE 1 A At the works of the manufacturer of dimethyl ether, a mixture of 1 6.7% by weight of dimethyl ether and 83.3% by weight of methylene chloride is produced by mixing in a container. This mixture is transported to the manufacurer of aerosol preparations and is further processed in the following way: B A hair-spray is prepared. For this purpose, i.36 g of a copolymer of N-vinylpyrrolidone and vinyl acetate in a weight ratio of 30 : 70, 0.10 g of perfume oil, 33.65 g of iso-propanol, 1 3.70 g of water and 3.97 g of acetone are dissolved and filled into a suitable aerosol container. The aerosol container is provided with a spray valve according to Figure 1 or Figure 3 or Figure 10, but without the turbulent-spray head 10.Subsequently, 41.64 g of a dimethyl ether/methylene chloride solution (1 6.7% by weight of dimethyl ether and 83.3% by weight of methylenechloride) and 4.57 g of carbon dioxide are injected through the spray valve into the aerosol container. A turbulentspray head 10 is then placed onto the spray valve. The filled aerosol can is illustrated by Figure 1 3.

Due to the use of an aerosol preparation and of a device according to the invention, the spray properties of this aerosol filling largely correspond to the properties of corresponding hair-sprays which have been formulated with the use of fluorochlorohydrocarbons as the propellant.

EXAMPLE 2 A At the works of the manufacturer of dimethyl ether, a mixture of 18.6% by weight of dimethyl ether and 81.4% by weight of methylene chloride is produced by mixing in a container. This mixture is transported to the manufacturer of aerosol preparations and is further processed in the following way: B A hair-spray is prepared. For this purpose, 2.47 g of a copolymer of N-vinylpyrrolidone and vinyl acetate in a weight ratio of 30 : 70, 0.1 9 of perfume oil, 32.86 g of ethanol, 14.35 g of water and 4.26 g of methoxyacetone are dissolved and filled into a suitable aerosol container. The aerosol container is provided with a spray valve according to Figure 1 or Figure 3 or Figure 10, but without the turbulent-spray head 1 0. Subsequently, 41.69 g of a dimethyl ether/methylene chloride solution (18.6% by weight of dimethyl ether and 81.4% by weight of methylene chloride) and 4.27 g of carbon dioxide are injected through the spray valve into the aerosol container. A turbulentspray head 10 is then placed onto the spray valve. The filled aerosol container is illustrated by Figure 13.

Due to the use of an aerosol preparation and of a device according to the invention, the spray properties of this aerosol filling largely correspond to the properties of corresponding hair-spray products which have been formulated with the use of fluorochlorohydrocarbons as the propellant.

EXAMPLE 3 A At the works of the manufacturer of dimethyl ether, a mixture of 6.6% by weight of dimethyl ether and 83.4% by weight of 1,1,1-trichloroethane is produced by mixing in a container. This mixture is transported to the manufacturer of aerosol preparations and is further processed in the following way: B A hair-spray is prepared. For this purpose, 2.08 g of a copolymer of N-vinylpyrrolidone and vinylacetate in a volume ratio of 70:30, 0.1 9 of perfume oil, 33.96 g of iso-propanol, 13.62 g of water and 3.72 g of acetone are dissolved and filled into a suitable aerosol container.The aerosol container is provided with a spray valve according to Figure1 or Figure 3 or Figure 10, but without the turbulentspray head 10. Subsequently, 41.95 g of a dimethyl ether/1,1,1-trichloroethane solution (16.6% by weight of dimethyl ether and 83.4% by weight of 1,1,1-trichloroethane) and 4.57 g of carbon dioxide are injected through the spray valve in the aerosol container. A turbulentspray head 10 is then placed into the spray valve. The filled aerosol container is illustrated by Figure 13.

Due to the use of an aerosol preparation and of a device according to the invention, the spray properties of this aerosol filling largely correspond to the properties of corresponding hair-spray products which have been formulated with the use of fluorochlorohydrocarbon propellants.

EXAMPLE 4 A At the works of the manufacturer of dimethyl ether, a mixture of 18.6% by weight of dimethyl ether and 81.4% by weight of 1,1,1-trichloroethane is produced by mixing in a container. This mixture is transported to the manufacturer of aerosol preparations and is further processed in the following way: B A deodorant spray is prepared. For this purpose, 0.10 g of 2,4,4'-trichloro-2'-hydroxydiphenyl ether, 2.37 g of benzoic acid ethyl ester, 14.35 g of water, 32.86 g of iso-propanol, 3.86 g of acetone and 0.50 g of perfume oil are dissolved and filled into a suitable aerosol container. The aerosol container is provided with a spray valve according to Figure 1 or Figure 3 or Figure 1 0, but without the turbulentspray head 10.

Subsequently, 41.69 g of a dimethyl ether/1 ,1 ,1 -trichloroethane solution (18.6% by weight of dimethyl ether and 81.4% by weight of 1 ,1 ,1 -trichloroethane) and 4.27 g of carbon dioxide are injected through the spray valve into the aerosol container. The turbulentspray head 10 is then placed onto the spray valve. The filled aerosol can is illustrated by Figure 1 3.

Due to the use of an aerosol preparation and of a device according to the invention, the spray properties of this aerosol filling largely correspond to the properties of corresponding deodorant spray products which have been formulated with the use of fluorochlorohydrocarbons as the propellant.

EXAMPLE 5 A At the works of the manufacturer of dimethyl ether, a mixture of 1 6.6% by weight of dimethyl ether and 83.4% by weight of 1,1,1 -trichloroethane is produced by mixing in a container. This mixture is transported to the manufacturer of aerosol preparations and is further processed in the following way: B A deodorant spray is prepared. For this purpose, 0.10 g of 2,4,4'-trichloro-2'-hydroxyphenyl ether, 1.98 g of benzoic acid ethyl ester 13.62 g of water, 33.56 g of ethanol, 3.72 g of methoxyacetone and 0.50 g of perfume oil are dissolved and filled into a suitable aerosol container. The aerosol container is provided with a spray valve according to Figure 1 or Figure 3 or Figure 10, but without the turbulentspray head 10.

Subsequently, 41.95 g of a dimethyl ether/1 ,1 ,1 -trichloroethane solution (16.6% by weight of dimethyl ether and 83.4% by weight of 1,1,1 -trichloroethane) and 4.57 g of carbon dioxide are injected through the spray valve into the aerosol container. A turbulentspray head 10 is then placed onto the spray valve. The filled aerosol can is illustrated by Figure 1 3.

In the above Examples 1-5 and the further investigations, an aerosol can according to Figure 13 was used, which was provided with a spray valve according to Figure 1 or Figure 3 or Figure 10.

The technical advance achieved by the homogeneous filling present in the aerosol can according to Figure 1 3 is indicated in Table I which follows, in comparison with the aerosol preparations according to German Offenlegungsschrift 2,705,872.

TABLE I Comparative data for the non-inflammable constituents in the aerosol preparation, to prove the technical advance achieved, taking into account German Offenlegungsschrift 2,705,872.

Example No. 1 2 3 4 5 6 7 8 9 10 State of the art in German Offenlegungsschrift 2,705,872, non-inflammable constituents in per cent by weight 37 40 38 36 31 25 18 35.2 35.2 25 Aerosol preparation according to the invention, non-inflammable constituents in per cent by weight 55.23 55.02 55.25 55.02 55.28 In calculating the comparative data for the non-inflammable constituents, the following components were taken into account:: hair-spray resin, methylene chloride, water, carbon dioxide, 2,4,4'-trichloro-2'-hydroxydiphenyl ether, 1,1,1 -trichloroethane and benzoic acid ethyl ester.

The aluminium chlorohydroxide/propylene glycol complex contained in Example 10 of German Offenlegungsschrift 2,705,872 was assumed to be non-inflammable to the extent of 50 per cent by weight.

The above comparative data show that the pesent invention provides an aerosol preparation which is improved by a major step-change since, according to the state of the art, 40 per cent by weight of non inflammable constituents are contained, in the most favourable case, in the aerosol preparation free from fluorohydrocarbons, whilst the content of non-inflammable constituents is at least 55.02 per cent by weight in all the examples in the aerosol preparation according to the invention.

The second special use, already briefly indicated, of mixtures of water and dimethyl ether, which mixtures are obtained according to the process of the invention, for the manufacture of aerosol preparations will now be described in more detail.

In this case, a pressurised carrier mixture for aerosol preparations of a self-propelling spray system for use as a universal spray based on active ingredients which are to be applied, organic solvents, water and propellants is prepared in a spray container, the carrier mixture being present as a homogeneous solution and the latter containing 70.0-50.1 per cent by weight of water, 38.5-28.7 per cent by weight of dimethyl ether, 0.5-10.0 per cent by weight of iso-propanol and/or ethanol and/or n-propanol and 1.4-0.8 per cent by weight of carbon dioxide wherein the percentage by weight data must add up to 100 per cent by weight.

In the sense of this invention, non-inflammable constituents are understood to be water, carbon dioxide and those other constituents, for example active ingredients, which have an ignition temperature above 6000C.

The carrier mixtures, according to the invention, of the aerosol preparations can be formulated with cosmetic or hygienically or medically active constituents (active ingredients) and give preparations for diverse purposes, for example as a cosmetic spray, room spray or medicinal spray, preferably as deodorant sprays.

The active constituents can, for example, be hair-care substances, hair-spray resin, antiperspirants, deodorants, bactericides, perfume, fungicides, pliant extracts and/or organ extracts.

The aqueous carrier mixture used in the aerosol preparations according to the invention is based on the propellant gases carbon dioxide and dimethyl ether as the propellant.

An embodiment of the carrier mixture is characterised in that it contains 0.8-1.1 per cent by weight of carbon dioxide and 28.7-38.5 per cent by weight of dimethyl ether as the propellant gases, the percentages by weight relating to the total weight of the aqueous carrier mixture.

Another embodiment of the carrier mixture is characterised in that it contains 54.0--70.0 per cent by weight of water, the percentages byweight relating to the total weight of the aqueous carrier mixture.

A further embodiment of the carrier mixture is ch racterised in that it contains 5.0-10.0 per cent by weight of organic solvents, the percentages by weight relating to the total weight of the aqueous carrier mixture.

In a very particulaily preferred embodiment, the carrier mixture is characterised in that it contains 54.0--5 5.0 per cent by weight of water, 0.9- 1.1 per cent by weight of carbon dioxide, 38.5-35.1 per cent by weight of dimethyl ether and 9.0- 6.4 per cent by weight of alcohols having 2 and/or 3 C atoms, wherein the indicated percentages by weight must add up to 100 per cent by weight.

In the preparation of the carrier mixture or the aerosol preparations according to the invention, the nature and amount of required active ingredient, alcohols of the stated types, carbon dioxide, dimethyl ether as well as water are, taking into account the intended use, qualitatively and quantitatively matched in a trial batch in such a way, taking into account the ranges of percentages by weight indicated above, that a homogeneous solution is formed as a single phase which can be sprayed perfectly to give a ready-to-use aerosol.

In the carrier mixtures prepared for aerosol preparations of the above very particularly preferred embodiment, the content of non-inflammable constituents was 55.1-55.9 per cent by weight.

Compositions of suitable carrier mixtures are indicated in Table II.

EXAMPLE 6 A At the works of the manufacturer of dimethyl ether, a mixture of 30.0% by weight of dimethyl ether and 70.0% by weight of water is produced by mixing in a container. This mixture is transported to the manufacturer of aerosol preparations and is further processed in the following way.

B A hair-care product is prepared analogously to the carrier mixture J indicated in Table II. For this purpose, 0.80 of polyvinylpyrrolidone, 0.10 g of perfume oil and 6.86 g of iso-propanol are filled into a suitable aerosol container. The aerosol container is provided with a spray valve according to Figure 1 or Figure 3 or Figure 10, but without the turbulent-spray head 10. Subsequently, 77.04 g of aqueous dimethyl ether solution (30% by weight of dimethyl ether and 70% by weight of water), 1 4.11 g of dimethyl ether and 1.09 g of carbon dioxide are injected through the spray valve into the aerosol container. A turbulent-spray head 10 is then placed onto the spray valve. The filled aerosol can is illustrated by Figure 1 3.

Due to the use of a carrier mixture and of a device according to the invention, the spray properties of this aerosol filling largely correspond to the properties of corresponding hair-care products which have been formulated with the use of fluorochlorohydrocarbons as the propellant.

EXAMPLE 7 A The procedure followed is as indicated in Example 6, part A.

B A deodorant spray preparation according to the following formulation is prepared analogously to the carrier mixture H indicated in Table II: 98.00% by weight of carrier mixture H, 0.10% by weight of a bactericide for deodorant spray, 0.50% by weight of perfume oil, 0.30% by weight of a solubiliser and 1.10% by weight of a superfatting agent for deodorant spray.

For this purpose, 0.10 g of a bactericide for deodorant spray, 0.50 g of perfume oil, 0.30 g of a solubiliser and 1.1 0 g of a super fatting agent for deodorant spray are dissolved in 8.40 g of ethanol and filled into a suitable aerosol container. The aerosol container is provided with a spray valve according to Figure 1 or Figure 3 or Figure 10, but without the turbulent-spray head 1 0.

Subsequently, 76.57 g of aqueous dimethyl ether solution (30% by weight of dimethyl ether and 70% by weight of water), 12.03 g of dimethyl ether and 1.00 g of carbon dioxide are injected through the spray valve into the aerosol container. The turbulentspray head 10 is then placed onto the spray valve. The filled aerosol can is illustrated by Figure 1 3.

Due to the use of a carrier mixture and of a device according to the invention, the spray properties of this aerosol filling largely correspond to the properties of corresponding deodorant spray products which have been formulated with the use of fluorochlorohydrocarbons as the propellant.

EXAMPLE 8 A The procedure followed is as indicated in Example 6, part A.

An antiperspirant spray preparation having the following formulation is prepared analogously to the carrier mixture I indicated in Table II: 96.7% by weight of carrier mixture I, 3.0 /0 by weight of a perspiration inhibitor and 0.3% by weight of perfume oil.

For this purpose, 3.0 g of a perspiration inhibitor, 0.3 g of perfume oil, 10.0 g of water and 9.67 g of ethanol are dissolved and filled into a suitable aerosol container. The aerosol container is provided with a spray valve according to Figure 1 or Figure 3 or Figure 10, but without the turbulentspray head 1 0. Subsequently, 60.31 g of aqueous dimethyl ether solution (30% by weight of dimethyl ether and 70% by weight of water), 15.75 g of dimethyl ether and 0.97 g of carbon dioxide are injected through the spray-valve into the aerosol container. A turbulent spray head 10 is then placed onto the spray valve. The filled aerosol can is illustrated by Figure 13.

Due to the use of a carrier mixture and of a device according to the invention, the spray properties of this aerosol filling largely correspond to the properties of corresponding antiperspirant spray products which have been formulated with the use of fluorochlorohydrocarbons as the propellant.

TABLE II

Examples of carrier mixtures according to the invention, which forms a homogeneous liquid phase A B C D E F G H I J Constituents % by % by % by % by % by % by % by % by % by % by weight weight weight weight weight weight weighty weight weight weight Water 70.0 70.0 70.0 54.0 54.0 54.0 54.0 54.70 54.0 54.42 Dimethyl ether 28.7 28.7 28.7 35.0 35.0 38.5 38.0 35.71 35.0 37.56 Iso-propanol 0.5 10.0 7.0 6.92 Ethanol 0.5 10.0 6.5 8.57 10.0 n-Propanol 0.5 Carbon dioxide 0.8 0.8 0.8 1.0 1.0 1.0 1.0 1.0 10.2 1.0 1.10 Pressure in bar 6.8 6.9 7.0 5.5 6.3 5.7 5.7 6.4 6.3 5.7 TABLE 11 (Continued)

Examples of carrier mixtures according to the invention, which form a homogeneous liquid phase K L M Constituents % by % by % by weight weight weight Water 54.0 54.0 54.0 Dimethyl ether 35.0 38.0 38.5 Iso-propanol 1.0 6.0 Ethanol 8.0 5.5 n-Propanol 1.0 1.0 1.0 Carbon dioxide 1.0 1.0 1.0 Pressure in bar 6.0 5.7 5.7 The carrier mixtures according to the invention have a pressure of about 5 to about 7 bars at 20 C Further investigations have shown that, as a result of the appropriate addition of active ingredients and conventional additives, the carrier mixtures H and I in Table II are outstandingly suitable for the manufacture of aerosol preparations for toiletries, hair-care requisites, household articles, medicinal sprays, technical aerosols and perfume-atomising agents.

EXAMPLE 9 A At the works of the manufacturer of dimethyl ether, a mixture of 36.08% by weight of dimethyl ether, 55.26% by weight of water and 8.66% by weight of ethanol is produced by mixing in a container.

This mixture is transported to the manufacturer of aerosol preparations and is further processed in the following way.

B A dedorant spray preparation according to the following formulation is prepared analogously to the carrier mixture H indicated in Table II: 98.00% by weight of carrier mixture H, 0.10% by weight of a bactericide for deodorant spray, 0.50% by weight of perfume oil, 0.30% by weight of a solubiliser and 1.1 0% by weight of a superfatting agent for deodorant spray.

For this purpose, 0.10 g of a bactericide for deodorant spray, 0.50 g of perfume oil, 0.30 g of a solubiliser and 1.10 g of a superfatting agent for deodorant spray are filled into a suitable aerosol container. The aerosol container is provided with a spray valve according to Figure 1 or Figure 3 or Figure 10, but without the turbulent-spray head 10. Subsequently, 97.00 g of a single-phase aqueous-alcoholic dimethyl ether solution (36.08% by weight of dimethyl ether, 55.26% by weight of water and 8.66% by weight of ethanol) and 1.00 g of carbon dioxide are injected through the spray valve into the aerosol container. The turbulentspray head 10 is then placed onto the spray valve. The filled aerosol can is illustrated by Figure 1 3.

Due to the use of a carrier mixture and of a device according to the invention, the spray properties of this aerosol filling largely correspond to the properties of corresponding deodorant spray products which have been formulated with fluorochlorohydrocarbons as the propellant.

EXAMPLE 10 A At the works of the manufacturer of dimethyl ether, a mixture of 35.35% by weight dimethyl ether, 54.55% by weight of water and 10.10% by weight of ethanol is produced by mixing in a container. This mixture is transported to the manufacturer of aerosol preparations and is further processed in the following way.

B An antiperspirant spray preparation having the following formulation is prepared analogously to the carrier mixture I indicated in Table II: 96.70% by weight of carrier mixture I, 3.00% by weight of a perspiration inhibitor and 0.30% by weight of perfume oil.

For this purpose, 3.0 g of a perspiration inhibitor and 0.3 g of perfume oil are fillied into a suitable aerosol container. The aerosol container is provided with a spray valve according to Figure 1 or Figure 3 or Figure 10, but without the turbulent-spray head 10.

Subsequently, 95.73 g of a single-phase aqueous-alcoholic dimethyl ether solution (35.35% by weight of dimethyl ether, 54.55% by weight of water and 10.10% by weight of ethanol) and 0.97 g of carbon dioxide are injected through the spray valve into the aerosol container. A turbulentspray head 10 is then placed onto the spray valve. The filled aerosol can is illustrated by Figure 1 3.

Due to the use of a carrier mixture and of a device according to the invention, the spray properties of this aerosol filling largely correspond to the properties of corresponding antiperspirant spray products which have been formulated with fluorochlorohydrocarbons as the propellant.

EXAMPLE 11 A At the works of the manufacturer of dimethyl ether, a mixture of 37.98% by weight of dimethyl ether, 55.02% by weight of water and 7.00% by weight of iso-propyl alcohol is produced by mixing in a container.

A hair-care product is prepared analogously to the carrier mixture J indicated in Table II.

For this purpose, 0.80 g of polyvinylpyrrolidone and 0.10 g of perfume oil are filled into a suitable aerosol container. The aerosol container is provided with a spray valve according to Figure 1 or Figure 3 or Figure 10, but without the turbulent-spray head 10.

Subsequently, 98.01 g of a single-phase aqueous/iso-propyl alcoholic dimethyl ether solution (37.98% by weight of dimethyl ether,55.02% by weight of water and 7.00% by weight of iso-propyl alcohol) and 1.09 g of carbon dioxide are injected through the spray valve into the aerosol container. A turbulent spray head 10 is then placed onto the spray valve. The filled aerosol can is illustrated by Figure 1 3.

EXAMPLE 12 The formulation according to the data in Example 9 is prepared but -- differing from that Example - the indicated quantity of bactericide, perfume oil, solubiliser and superfatting agent is dissolved beforehand, in a mixing tank, in the carrier mixture H which is still free from carbon dioxide. The mixture is then injected into an aerosol container which is provided with a spray valve placed thereon, but without the turbulent-spray head 10.

Subsequently, the indicated quantity of carbon dioxide is injected through the spray valve into the aerosol container. The turbulent-spray head 10 is then placed onto the spray valve.

The spray properties of this aerosol filling correspond to those of the filling according to Example 9.

EXAMPLE 13 The formulation according to the data in Example 10 is prepared. Differing from the latter, however the procedure indicated in Example 12 is followed.

The spray properties of this aerosol filling correspond to those of the filling according to Example 10.

EXAMPLE 14 The formulation according to the data in Example 11 is prepared. Differing from the latter, however, the procedure indicated in Example 12 is followed.

The spray properties of this aerosol filling correspond to those of the filling according to Example 11.

In the above Examples, 2,4,4'-trichloro-2'-hydroxyphenyl ether, for example, can be used as the bactericide for deodorant spray. In the above Examples, castor oil which has been hydrogenated and exthoxylated with about 40 mols of ethylene oxide per mol can, for example, be employed as the solubiliser for deodorant spray. The superfatting agent for deodorant spray used in the above Examples can, for example, be polyethylene glycol having an average molecular weight of 400. The perspiration inhibitor employed in the above Examples can, for example, be aluminium hydroxychloride.

TABLE III Comparative data for the non-inflammable constituents in the aerosol preparation or carrier mixture, to prove the technical advance achieved, taking into account German Offenlegungsschrift 2,705,872.

Example No. 1 2 3 4 5 6 7 8 9 10 State of the art, German Offenlegungsschrift 2,705,872, non-inflammable constituents in per cent by weight 37 40 38 36 31 25 18 35.2 35.2 25 Carrier micture according to the A B C D E F G H I J invention, non-inflammable constiuents in per cent by weight 70.8 70.8 70.8 55.0 55.0 55.0 55.0 55.72 55.0 55.52 Example No. 6 7 8 9 10 11 12 13 14 Aerosol preparations made from the carrier mixture according to the invention 55.82 55.0 56.19 55.0 56.19 55.82 55.0 56.19 55.82 When calculating the comparative data for the non-inflamable constituents, the following components were taken into account: 1. According to German Offenlegungsschrift 2,705,872: hair-spray resin, methylene chloride, water and 1 , 1 , 1 -trichloroethane; the aluminium chlorohydroxide/propylene glycol complex contained in Example 10 was assumed to be non-inflammable to the extent of 50% by weight.

2. According to the present invention: hair-spray resin, water, carbon dioxide, bactericide, perspiration inhibitor and solubiliser. The above comparative data show that the present invention provides carrier mixtures or aerosol preparations which are improved by a major step-change since, according to the state of the art, 40% by weight of non-inflammable constituents are contained, in the most fovourable case, in the aerosol preparation free from fluorochlorohydrocarbons, whilst the content of noninflammable constituents in all the examples is at least 55% by weight in the carrier mixture according to the invention.

Claims

1. Process for the manufacture of a dimethyl ether preparation which can be safely transported, characterised in that a) dimethyl ether is mixed with water under pressure to give a homogeneous solution, or that b) dimethyl ether is mixed with methylene chloride and/or 1,1,1 -trichloroethane under pressure to give a homogeneous solution and a mixture of a) or b) is used, or the two mixtures a) and b) are used, as a propellant for the production of carrier mixtures in aerosol preparations.

2. Process according to Claim 1, wherein in a) about 6.0 to about 32.0% by weight of dimethyl ether and about 68.0 to about 94.0% by weight of water are used, and the % by weight of the two components must add up to 100% by weight.

3. Process according to Claim 1, wherein in a) about 27.0 to about 32.0% by weight of dimethyl ether and about 68.0 to about 73.0% by weight of water are used, and the % by weight of the two components must add up to 100% by weight.

4. Process according to Claim 1, wherein in b) about 10.0 to about 45.0% by weight of dimethyl ether and about 55.0 to about 90.0% by weight of methylene chloride and/or 1,1,1 -trichloroethane are used, and the % by weight of the components must add up to 1 00% by weight.

5. Process according to any one of Claim 1 to 4, wherein the mixture a) or b) is prepared in the presence of up to about 11% by weight of ethanol and/or n-propanol and/or iso-propanol, the percentage by weight data relating to the weight of the mixture a) or the mixture b) respectively.

6. Process according to Claim 1 ,wherein in a) about 10.0 to about 40.0% by weight of dimethyl ether, about 15.0 to about 5.0% by weight of ethyl alcohol and/or iso-propanol and/or n-propanol and about 85.0 to about 45.0% by weight of water are used, and the % by weight of the components must add up to 100% by weight.

7. Process according to Claim 1, wherein in b) about 10.0 to about 40.0% by weight of dimethyl ether, about 1 5.0 to about 5.0% by weight of ethyl alcohol and/or iso-propanol and/or n-propanol and about 85.0 to about 45.0% by weight of methylene chloride and/or 1,1 1-trichloroethane are used, and the % by weight of the components must add up to 100% by weight.

8. Use of the dimethyl ether mixtures, obtainable in accordance with any one of Claims 1 to 7, as a propellant in pressurised carrier mixtures for aerosol preparations or in aerosol preparations.

9. Use of the homogeneous solution, prepared in accordance with any one of Claims 1 to 7, as a propellant filling in aerosol cans which, formulated as a medicinal spray cosmetic spray, room spray or universal spray, are provided with a self-closing spray valve, as a super-fine atomisation valve, for pressure containers which contain solutions of a gas and/or'liquid, having a valve stem which, inside a valve housing, is axially movable in the direction of opening against the action of a closing compression spring which is backed up by the valve housing, an axial outlet channel in the valve stem being connected to the interior of the pressure container by means of a radial outlet channel which ends in an.

annular groove in the valve stem, the radial outlet channel thereof being sealed, in the closed position, by an elastic annular grommet, the cylindrical internal circumference of which engages in the annular groove with a radial bias and the external edge of which is not clamped between the valve housing and the dome of the cap, the shoulder, which faces the container, of the annular groove, when in the closed position, being in tight contact with the grommet under the action of the closing compression spring, whilst the forces which are exerted by the annular groove in the valve stem on the circumferential sections, which are above the neutral bending zone, of the hole in the grommet are composed of a force component which is in each case radial to the valve stem and of a force component which is parallel to the axis, which components are greatest at the upper edge, and, when the valve is closed, the forces which are exerted by the annular groove in the valve stem on the circumferential sections, which are below the neutral bending zone, of the hole in the grommet are also composed of a force component which is in each case radial to the valve stem and of a force component which is parallel to the axis, these force components being greatest at the lower edge of the hole of the grommet, which aerosol can is in a form adapted to the specific intended use by combining the embodiments a, b, c, d, e and fin such a way that a) a restrictor in the shape of a body with a cylindrical bore is located in compression in the axial outlet channel of the valve stem part and, in the centrally arranged restricting channel, a bridge member is provided which is located in the centre of the restrictor and contains the passage orifice, b) the turbulent-spray head with the inserted turbulence jet is firmly but releasably attached and the spray head has a cylindrical jet-receiving plug having two surfaces which are parallel to the axis and, as viewed from the jet orifice, are vertically arranged, c) the jet-receiving plug carries the forced-on turbulence jet four raised webs of which rest on the end face of the jet-receivig plug, d) the four webs around the jet orifice on the inside of the turbulence jet form an approximately cylindrical turbulence chamber and the webs free the linlet channels which are in a location tangential to the circular jet orifice, e) a cylindrical recess is located on the outer surface of the turbulence jet, concentrically to the iet orifice, and f) the turbulent-spray head contains an approximately eccentrically arranged, tapering chamber which communicates with the annular channel and merges into the receiving opening which is located underneath and is to receive the valve stem part, for the purpose of a super-fine atomisation of the spray preparation filled in.

1 0. Process according to Claim 1 substantially as hereinbefore described in any of the Examples.

11. A dimethyl ether preparation when prepared a process according to any one of Claims 1 to 7 and 10.

12. An aerosol can containing a preparation according to Claim 11.

1 3. An aerosol can according to Claim 12 substantially as described with reference to the drawings.