NL8502521A - STABILIZERS FOR ALKYL HALOGENIDES AND THEIR USE IN AEROSOL PREPARATIONS. - Google Patents

Description

NL 33018-Kp / dJ / cs

Stabilizers for alkyl halides and their use in aerosol preparations.

The present patent application concerns the stabilization of halohydrocarbons and halocarbons against decomposition after a long time in aerosol containers.

Alkyl halides which are liquid in the closed aerosol container 5 at room temperature under their own pressure are particularly suitable. Halocarbons, such as, for example, trichloromofluoromethane, dichlorodifluoromethane and 1,2-dichlorotetrafluoroethane, are currently used as propellant or solvent. Furthermore, a commonly used solvent in aerosol formulations is methylene chloride.

When aqueous aerosol preparations are used in aerosol containers of galvanized steel sheet or aluminum, a more or less slow hydrolysis of the alkyl halides takes place to form hydrogen halide. This leads to corrosion of the metal on the inner walls of the aerosol container. Furthermore, the metal salts formed have a negative influence on the odor of the perfume oils which are always present therein. In addition, hydrogen halide reacts chemically with many of the active substances present in the aerosol preparation and renders them inoperable in this way.

The complete replacement of the alkyl halides with halogen-free propellants, such as, for example, propane and butane, leads, in addition to solubility problems, to an increased flammability of the preparations.

As a result of the entry into force of TRG 300 as well as similar regulations within the framework of the European Community, the above-mentioned alkyl halides 30 are used for reducing flammability in larger quantities and therefore represent an important corrosion risk.

Therefore, numerous attempts have been made in the past to reduce the hydrolysis sensitivity of the alkyl halides by stabilization. At the same time, attempts have been made to suppress or prevent corrosion by adding corrosion inhibitors. An effective combination, which also complies with the ingredients legislation, has not yet been found.

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Therefore, the task was to stabilize the alkyl halides against hydrolysis and at the same time find an effective corrosion inhibitor.

According to the invention it has been found that with a single substance both the hydrolysis and the corrosion can be prevented, and that consequently a negative influence on the odor of the perfume oil or the change of other components of the aerosol preparation can be avoided.

The task was fulfilled by the use of β-caro-10 toe or ethylene carbonate as stabilizer or corrosion inhibitor in aerosol preparations based on alkyl halides.

The above-mentioned stabilizers or corrosion inhibitors should be used in the aerosol formulations in an amount of 0.001-1.0 wt.%, Preferably 0.05-0.5 wt.%.

The invention also furthermore includes stabilized aerosol preparations based on alkyl halides as propellant and / or solvent, and with a content of 0.001-1.0% by weight of a stabilizer or corrosion inhibitor, characterized in that the stabilizer or corrosion inhibitor is selected from β-carotene and ethylene carbonate.

The aerosol preparations according to the invention preferably contain at least traces of water and in particular have the following composition: 5.0 -90.0 wt.% Alkyl halides 0.1 -25.0 wt.% Water 0.1 -35.0 wt. % active ingredients 30 -70.0 wt% halogen-free propellants 0 -75.0 wt% organic solvents 0.001-1.0 wt% stabilizer, being β-carotene or ethylene carbonate 100.0 wt% Of the alkyl halides present as a solvent and / or propellant in the present aerosol preparations, mainly halocarbons, such as, for example, trichloromonofluoromethane (CCI3F), dichlorodifluoromethane (CCI2F2), trichlorotrifluoroethane (C2CI3F3) and 1,2-dichloro-tetrafluoroethyl (tetrafluoroethyl) -CCIF2), as well as halohydrocarbons, such as, for example, dichloro monofluoromethane (CHCI2F), monochlorodifluoromethane (CHCIF2), 1,2-difluoroethane (CH2F-CH2F), mono-3-chloro-1,2-difluoroethane (CHCIF-CH2F), 1,1,1-trichloroethane (CCI3-CH3) and methylene chloride (CCI2H2).

The aerosol preparations contain as active substance any active substances customary for aerosol preparations. The term "active substance" in the present application is to be understood to mean substances which are not to be regarded as gaseous or liquid alkyl halides, halogen-free propellants, organic solvents or as stabilizers, but which are nevertheless a necessary component of aerosol preparations. Examples include perfumes, dyes, deodorants, fungicides, bactericides, insecticides and resins. The active substances should preferably be cosmetic active substances, for example resins suitable for hair sprays, such as copolymers of vinyl acetate and crotonic acid, polyvinylpyrrolidone, vinylpyrrolidone-vinyl acetate copolymers, polyacrylic acid, polymethacrylic acid, acrylic acid-methacrylic acid copolymers filtering agents for sun protection sprays or cosmetic dyes adhering directly to the hair, such as, for example, aromatic nitro dyes, azo dyes, anthraquinone dyes and triphenylmethane dyes, in addition, anti-dandruff agents, perfume oils and others. If the aerosol formulation is a hair spray, then the cosmetic resin is contained therein in an amount of about 0.5-4% by weight.

The aerosol formulations of the invention may additionally contain up to 70% by weight of a halogen-free propellant. Gases CO2, N2O and N2 as well as dimethyl ether, n-propane, n-butane and i-butane are particularly suitable as halogen-free propellants.

If required, the aerosol preparations may further contain organic solvents, such as, for example, isopropanol, ethanol or acetone, in an amount of up to 75% by weight.

The aerosol formulations described above are also extremely stable during long-term storage and do not cause corrosion of the aerosol container.

The following examples serve to illustrate the subject of the invention.

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EXAMPLE 1 Hair spray 20.00 g trichlormonofluoromethane 35.00 g methylene chloride 1.00 g water 5 2.00 g copolymer of vinylpyrrolidone and vinyl acetate (50:50) 0.20 g perfume oil 21.79 g mixture of n-propane / n-butane in the ratio 60:40 10.00 g isopropanol 10 10.00 g acetone 0.01 g ethylene carbonate 100.00 g

Each time, samples of the above composition were tapped into tin aerosol containers (tin layer E1, 15 welded, without lacquer seam cover), respectively. in aluminum monoblock boxes with an internal protective lacquer made of phenolic resin and at temperatures of 20 ° C or. 40 ° C stored together with control samples of the same composition, but without ethylene carbonate. The opened control samples 20 already showed, after a storage period of 6 months, both at a storage temperature of 40 ° C and also at a storage temperature of 20 ° C, a large surface attack of the tin coating and a clearly noticeable change in the odor of the used. perfume oil. After a storage period of 25 years, the preparation of the control samples is clearly discolored and the inner walls of the aerosol container show a strong corrosion. In the aerosol preparation according to Example I, on the other hand, even after a storage period of 12 months, neither a change in the ingredients nor a corrosion of the aerosol container can be detected.

EXAMPLE 2 Hair spray 20.0 g trichlormonofluoromethane 35.0 g methylene chloride 1.5 g water 35 2.0 g copolymer of vinyl pyrrolidone and vinyl acetate (50:50) 0.3 g perfume oil 21.1 g mixture of n-propane / n-butane in the ratio 60: 40 10.0 g isopropanol 40 10.0 g acetone 0.1 q 3-carotene or ethylene carbonate 100.0 g

Claims (9)

1. Use of 3-carotene or ethylene carbonate as a stabilizer or corrosion inhibitor in aerosol preparations based on alkyl halides. 2. Use according to claim 1, characterized in that the alkyl halides are selected from methylene chloride, 1,1,1-trichloroethane and trichloro monofluoromethane. 3. Use according to claims 1 and 2, characterized in that the stabilizer or corrosion inhibitor is used in an amount of 0.001-1.0% by weight. 4. Stabilized aerosol preparation based on alkyl halides as propellant and / or solvent and with a content of 0.001-1.0% by weight of a stabilizer or corrosion inhibitor, characterized in that the stabilizer or corrosion inhibitor is selected from 3-carotene and ethylene carbonate. Aerosol preparation according to claim 4, characterized in that it contains 0.1-25% by weight of water. Aerosol preparation according to claims 4 and 5, characterized in that the alkyl halides are present in an amount of 5-89.3% by weight. Aerosol preparation according to claims 4-6, characterized in that the alkyl halides are selected from methylene chloride, 1,1,1-trichloroethane and trichloromonofluoromethane. 8. Aerosol preparation according to claims 4-7, consisting of 5.0 -90.0 wt.% Alkyl halides 0.1 -25.0 wt.% Water 30 0.1 -35.0 wt.% Active substances 0 -70, 0 wt% halogen-free propellants 0 -75.0 wt% organic solvents 0.001-1.0 wt% stabilizer selected from 3-carotene and ____ ethylene carbonate 35 100.0 wt% Aerosol preparation according to claims 4-8, characterized in that it is a hair spray. 85 0 2 52 1 '