GB2042890A - Antiperspirants/deodorants containing fragrance-imparting silicon compounds - Google Patents

Abstract

An antiperspirant and/or deodorant composition comprising an astringent substance and/or an antibacterial substance and a fragrance-imparting ingredient which is a silicon compound, for example a silane or a siloxane having at least one silicon bonded group -OR in which R represents the residue remaining after removal of a hydroxyl group from a perfume alcohol e.g. geraniol, citronellol or phenylethyl alcohol.

Description

SPECIFICATION Cosmetic compositions containing silicon compounds This invention relates to cosmetic compositions. More particularly the invention is concerned with antiperspirant and/or deodorant compositions having a silicon-containing fragrance-imparting component.

Aerosol antiperspirant compositions containing an astrigent substance such as aluminium chlorohydroxide are well-known in the art. Also known are deodorant compositions which rely for their effectiveness on the presence of an antibacterial substance. As with most cosmetic preparations it is customary to incorporate into such compositions a perfume which provides a degree of aesthetic appeal and also assists in the masking of unpleasant odours. The perfumes employed for this purpose are usually based on the essential alcohols such as geraniol, citronellol and phenylethyl alcohol.

We have now found that certain silicon-modified essential alcohols can be employed as fragranceimparting additives for antiperspirant and deodorant compositions. We have also found that the fragrance imparted by such silicon compounds is usually at least as persistent as that imparted by the corresponding essential alcohols themselves and, at least in some cases, can persist for a longer period.

Accordingly this invention provides an antiperspirant and/or deodorant composition comprising an astringent substance and/or an antibacterial substance, and as a fragrance-imparting ingredient at least one silicon compound having attached to silicon at least one group of the general formula OR wherein R represents the residue remaining after removal of the hydroxyl group from an alcohol selected from cyclic and acyclic monoterpene alcohols, essential aryl-substituted aliphatic alcohols and essential aliphatic-substituted phenols.

This invention also provides a process for preparing such a composition which comprises mixing an astringent substance and/or an antibacterial substance with a silicon-containing fragrance-imparting substance of the type hereinabove defined.

Any silicon compound containing at least one of the specified silicon-bonded -OR groups in the molecule may be employed in the compositions of this invention. Thus the silicaon compounds may be for example a silane, di- or poly-silane, a siloxane or a silalkylene-siloxane. Preferred as the silicon compounds are (i) silanes represented by the general formula RtnSi(OR)4-n and (ii) siloxanes having at least one structural unit of the formula

any remaining units in the siloxane having the formula

wherein R is as defined hereinabove, R' and R" each represent a hydrogen atom or an organic group free of sulphur and phosphorus and attached to the silicon atom through a silicon to carbon or siliconoxygen-carbon linkage, n is 0, 1, 2 or 3, a has a value of 0, 1 or 2, b has a value of 1 or 2, the sum of a and b being not greater than 3, and c has a value of 0, 1, 2 or 3.

In the silicon compounds employed according to this invention the group R represents the residue remaining after removal of the hydroxyl group from an alcohol selected from cyclic and acyclic monoterpene alcohols, essential aryl-substituted aliphatic alcohols and essential aliphatic-substituted phenols. Such alcohols are well-known substances and include geraniol, citronellol, nerol, rhodinol, menthol, isopulegol, eugenol, vanillin, phenylethyl alcohol, phenylpropyl alcohol anisyl alcohol, and cinnamyl alcohol. If desired more than one type of OR group may be present in a given molecule of the silicon compound. Depending on the nature of fragrance desired the silicon compound maQ,have R groups derived from, for example, both geraniol and phenylethyl alcohol or from nerol and anisyl alcohol.The preferred alcohols are the rose alcohols and essential aryl-substituted aliphatic alcohols. Preferably, therefore, R represents a group selected from -CH2CH=C(CH3)(CH2)2CH=C(0H3)2, -(CH2)2CH3CH(CH2)2CH=C(CH3)2, -(CH2)2C6H5, -(CH2)3C8H5, -CH2PhOCH3 in which Ph represents phenylene, and CH2CH=CHC6H5.

Any substituents present in the silicon compounds in addition to the OR groups are hydrogen atoms and/or organic groups bonded to silicon through an SiC or SiOC linkage. Such organic groups, including R' and R", are preferably monovalent hydrocarbon groups, for example alkyl, alkenyl, aryl, alkaryl or aralkyl or monovalent groups composed of carbon, hydrogen and oxygen, for example alkoxy, alkoxyalkoxy or aryloxy. The SiC bonded organic groups may, however, also be monovalent halohydrocarbon groups such as chloroalkyl and chloroaryl.Specific examples or the organic substituents which may be present in addition to the OR groups are methyl, ethyl, propyl, butyl, 2,4,4trimethylpentyl, octadecyl, phenyl, benzyl, tolyl, methoxy, ethoxy, butoxy, methoxyethoxy, phenoxy, benzyloxy, -(CH2)3 (OCH2 CH2 ) OC4 H -CH2CH2OCH2CH3,

-(OH2)NH2, + -(CH,), NH(CH,), NH,, -CH2CH2CH(CH3) NH(CH2)2NH2 and -(CH2 )3 N(CH3) 2 C18 H37 Cl.

Preferably any substituents present in addition to the OR groups are selected from hydrogen atoms, methyl groups and alkoxy and alkoxyalkoxy groups having less than 5 carbon atoms.

When siloxanes are employed as the silicon compounds according to this invention they may be homopolymers containing only units of general formula (I) or they may consist of such units together with one or more units defined by general formula (II) hereinabove. Depending on the proportions and types of units present the siloxanes may have on average from less than 1.0 up to 3 total substituents per silicon atom and may vary from freely flowing liquid to resinous solids.

Examples of the silicon compounds which can be employed as the fragrance-imparting component in the compositions of this invention are CH3 (OCH3)2 SiOR (CH3)3 SiOR (OC2H5)3 SiOR Si (OR)4 C6HsSi(OR)3 CH2 = CHSi(OC2H5) (OR)2 C8H17 Si(OR)3 HSi(OR)3 Cl(CH2)3Si(OR)3 H2 N(CH2 )2 NH(CH2 )3 Si (CH3 ) (OR)2

partial hydrolysates of alkoxy silanes e.g. of Si(OC2H5)4 and CH3Si(OCH3)3, wherein some or all of the alkoxy groups have been replaced by OR groups.

The silicon compounds employed according to this invention may be prepared by the reaction of the appropriate alcohol, e.g. geraniol or phenylethyi alcohol, with a silicon compound having siliconbonded chlorine atoms or hydrogen atoms. It is usually preferred however to prepare the desired silicon compound by reacting the essential alcohol with a silicon compound having alkoxy or alkoxyalkoxy groups whereby some or all of such groups are replaced by the alcohol residue. Some reaction can take place merely by bringing the two reactants together. It is preferred, however, to expedite the reaction by the use of elevated temperatures and/or suitable catalysts, such as potassium carbonate, sodium hydroxide and metal organic compounds, e.g. tetrabutyl titanate.

More than one fragrance-imparting silicon compound may be incorporated into any given antiperspirant and/or deodorant composition. As is the case when conventional organic perfumes are employed two or more of the silicon compounds may be blended to achieve a particular fragrance.

Alternatively or additionally there may be employed one or more silicon compounds wherein the OR groups in at least one of them are derived from two or more different essential alcohols. Also, if desired, the silicon compound(s) may be employed in conjunction with one or more essential alcohols per Se.

In addition to the silicon-containing fragrance-imparting additive the compositions of this invention contain an astringent substance and/or an antibacterial substance. Astringent substances which can be employed in antiperspirant compositions and which can be present in the compositions of this invention are well known in the art. They include aluminium phenolsulphate, aluminium sulphamate, aluminium chlorhydroxide, aluminium alcoholate chloride, zinc sulphocarbolate, sodium zirconium lactate and zirconium sulphate. The preferred astringent substances are aluminium chlorhydroxide, particularly the "impalpable" form, and aluminium chlorhydroxide-propylene glycol complex.

The term "antibacterial agent" as employed herein includes both bactericides and bacteriostats.

Antibacterial agents which may be employed in the compositions of this invention include any of those which find application in deodorant compositions. Examples of such antibacterial agents are ethanol, isopropyl alcohol n-propyl alcohol, boric acid, sorbic acid, phenols, halogenated phenols, halogenated salicylic anilides, e.g. the dibromo- and tribromo-salicylic anilides, sulphur compounds such as captan, tetramethylthiuramide sulphide and zinc dimethyl dithiocarbamate and phenylmercuric salts.

In general the astringent/antibacterial component and fragrance-imparting component are employed in the compositions of this invention in proportions which are conventional in the preparation of antiperspirants/deodorants. Such proportions may vary widely depending on the nature and efficacy of the astringent/antibacterial ingredient. For example when ethanol is present as an antibacterial agent it may comprise 90% or more by weight of the total composition. On the other hand, the more highly potent bactericides need be present in only very small proportions, for example up to about 1% by weight of the total composition. The astringent substances are usually present in an amount of from 0.1 to 10% by weight, preferably 0.5 to 5% by weight based on the total weight of the composition.In some types of preparation both an astringent substance and an antibacterial substance may be present.

The fragrance-imparting silicon compounds may also be present in widely varying proportions.

Preferably they are employed in proportions of from 0.01 to 10% by weight based on the total weight of the composition.

As is well known in the art antiperspirant and deodorant compositions are available in a variety of forms, for example as aerosol preparations, as solid stick preparations and as pump sprays. The compositions of this invention may take any of these forms or, if desired, any other appropriate form, such as liquids for application from a rolling ball package.

In addition to the astringent/antibacterial substance and the fragrance imparting substance the compositions of this invention may contain other ingredients depending for example on the method of packaging and on the specific properties and effects desired in the product. Examples of such other ingredients are aerosol propellants e.g. the volatile hydrocarbons and halogenated hydrocarbons, organic solvents, water, thickening agents, e.g. treated clays and sodium alginate, lubricants e.g.

potassium stearate, inorganic fillers such as talc and silica, isopropylmyristate and polyalkylene glycols.

The addition of silicone fluids is also advantageous in as much as they impart lubricity and facilitate delivery of powdered astringents from aerosol packages. Particularly suited for this purpose are the linear and cyclic polydimethylsiloxanes, the linear methylphenylsiloxanes and copolymers of alkylsiloxanes and poly (alkylene oxides).

The following examples, in which: Me represents methyl X represents -OOH2CH=C(CH3)(CH2)2CH=O(CH3)2 Y representsO(CH2)2CH3CH(CH2)2CH=C(CH3)2 Z represents -0(CH2)2O9H5 illustrate the invention. In the examples the parts are expressed by weight.

EXAMPLE 1 Me Si(OMe)3 (13.6 parts) was refluxed with geraniol (30.8 parts) under a positive nitrogen pressure for 28 hours during which methyl alcohol was removed by means of a Dean and Stark apparatus. The resulting reaction mixture (Silane A) was found by gas-liquid chromatography to have the following composition by weight: Me Si(OMe)MMe OH 2.4% HO CH2CH=C(CH3) (CH2)2CH=C(CH3)2 14.2% Me Si(OMe)2X 13.0% Me Si(OMe)X2 48.6% Me SiX3 21.9% An antiperspirant composition was made up employing the following ingredients:: Aluminium Chlorohydrate 4.8 parts Octamethylcyclotetrasiloxane 2.4 parts Talc 2.6 parts Silane A 0.1 part Propellant* 90.1 parts * A mixture of equal volumes of dichlorodifluoromethane and chiorotrifluoromethane.

The composition was charged to an aerosol container. For comparison an identical. composition was prepared except that Silane A was replaced with the same quantity of geraniol.

Each composition was sprayed on to separate areas of human skin and the persistence of the characteristic geraniol odour observed. The patch sprayed with the composition containing Silane A retained a geraniol fragrance for at least 12 hours, the test being terminated when the sprayed area was washed. The patch sprayed with the comparison composition retained a geraniol fragrance for only 3 hours.

EXAMPLE 2 A deodorant composition was prepared having the following formulation: Ethyl alcohol 9.3 parts Copolymer of poly(methyl siloxane) and poly(ethylene oxide) 0.3 parts Dipropylene glycol 0.3 parts Silane A 0.1 part Propellant (as Example 1) 10.0 parts The composition was charged to an aerosol container. For comparison an identical composition was prepared except that Silane A was replaced with the same proportion of geraniol.

Each composition was sprayed on to separate areas of human skin and the persistence of the characteristic geraniol fragrance assessed. The patch sprayed with the composition containing Silane A retained a geraniol fragrance for at least 9 hours. The patch sprayed with the comparison composition has lost its fragrance after about 2 hours.

EXAMPLE 3 Citronellol (9.378 kg.) was reacted with methyltrimethoxy silane (4.08 kg.) in the presence of a catalyst. When the reaction was complete (as indicated by gas-liquid chromatographic analysis of the reaction mixture) volatiles were removed under vacuum to leave a liquid product (Silane B) containing the following: Me Si (OMe)2Y 11.0% by wt.

Me Si (OMe)Y2 36.6% by wt.

Me SiY3 38.3% by wit together with small percentages of unreacted starting materials and by-products e.g. methyl alcohol.

A deodorant composition was prepared according to the following formulation: Ethyl alcohol 92.5 parts Copolymer of poly(methylsiloxane) 3.0 parts and poly(ethylene oxide) Dipropylene glycol 3.0 parts Bactericide (Irgasan DP 300) 0.5 parts Silane B 1.0 parts and the composition charged to a conventional plastic pump spray package. For comparison a control formulation was prepared to the same formulation except that Silane B was replaced with an equal quantity of citronellol.

Both compositions were sprayed from their packages on to separate areas of skin on the arms of a human test subject and the sprayed portions examined periodically for residual fragrance. The fragrance imparted by the composition containing Silane B could be detected after 8 hours. whereas the fragrance imparted by the control compostion was undetectable after one hour.

EXAMPLE 4 Phenylethyl alcohol (7.32 kg.) was reacted with methyltrimethoxy silane (4.08 kg.) according to the general procedure described in Example 3. After removal of volatiles under vacuum the product (9.2 kg.) (Silane C) contained.

Me Si(OMe)2Z 10.5% by wt.

Me Si(OMe)Z2 32.8% by wt.

Me Z2Si O SiZ2Me 45.7% by wt.

together with small percentages of unreacted starting materials and by-products e.g. methyl alcohol.

A solid antiperspirant stick composition was prepared employing the following formulation: Stearic acid 7.0 parts Cetyl alcohol 7.5 parts Aluminium chlorohydrate 10.0 parts (microfine) Octamethylcyclotetrasiloxane 25.0 parts Silane C 0.5 parts The composition was tested by application to the skin of a human test subject. The characteristic odour of phenylethyl alcohol persisted on the skin for at least 12 hours, whereas the odour imparted by a control composition containing the alcohol in place of Silane C was undetectable after 4 hours.

Similar results were obtained when the procedure was repeated employing the reaction product of eugenol and methyl trimethoxysilane in place of Silane C. The skin patches treated with the silane reaction product retained a detectable odour of eugenol for 24 hours. In the case of the control containing eugenol itself no odour was detectable after about 12 hours.

EXAMPLE 5 A trimethylsiloxy-terminated polymer of MeHSiO units having a molecular weight of about 2500 (30 parts) was mixed with anhydrous potassium carbonate (0.1 part). This mixture was heated to 400C and 36 parts of a mixture of equal weights of geraniol, citronellol and phenylethyl alcohol added to it dropwise during 45 minutes. Heating was continued and the temperature of the reaction mixture maintained at about 1300C for 5 hours. Hydrogen was evolved during the reaction to leave a colourless, viscous, liquid siloxane (Siloxane D) having Me, X, Y and Z groups bonded to the silicon atoms. The siloxane also contained a proportion of unreacted silicon-bonded hydrogen atoms.

A solid antiperspirant composition was prepared according to the formulation described in Example 4 except that Silane C was replaced with 0.5 parts of Siioxane D. When the composition was tested as described in Example 4 it was found that skin treated with the composition retained its fragrance for at least 24 hours. Skin treated with a control composition containing a mixture of the alcohols in place of the siloxane had no discernible essential alcohol odour after about 3 hours.

Claims (9)

1. An antiperspirant and/or deodorant composition comprising an astringent substance and/or an antibacterial substance, and as a fragrance-imparting ingredient at least one silicon compound having attached to silicon at least one group of the general formulaOR wherein R represents the residue remaining after removal of the hydroxyl group from an alcohol selected from cyclic and acylic monoterpene alcohols, essential aryl-substituted aliphatic alcohols and essential aliphatic-substituted phenols.

2. A composition as claimed in Claim 1 wherein the silicon compound is a silane or a siloxane..

3. A composition as claimed in Claim 1 or Claim 2 wherein R represents a group selected from CH2CH=C(CH3)(CH2)2CH=C(CH3)2, -(CH2)2CH3CH(CH2)2CH=C(CH3)2, -(CH2)2CeHa, -(CH2)3C6H5, -CH2PhOCH2 in which Ph represents phenylene, and -CH2CH=CHC6H5.

4. A composition as claimed in any one of the preceding claims wherein any substituents present in the silicon compound in addition to the OR group or groups are selected from hydrogen atoms, methyl groups and alkoxy and alkoxyalkoxy groups having less than 5 carbon atoms.

5. A composition as claimed in any one of the preceding claims wherein the silicon-compound is present in a proportion of from 0.01 to 10% by weight based on the total weight of the composition.

6. A composition as claimed in any one of the preceding claims which also comprises one or more aerosol propellants.

7. A composition as claimed in Claim 6 which also comprises one or more of a linear polydimethylsiloxane, a cyclic polydimethylsiloxane, a linear methylphenylsiloxane and a copolymer of an alkylsiloxane and a polyalkylene oxide.

8. An antiperspirant and/or deodorant composition as claimed in Claim 1 substantially as described with reference to each of the Examples herein.

9. A process for preparing an antiperspirant and/or deodorant composition which comprises forming a composition containing at least one astringent and/or antibacterial substance and at least one silicon compound as defined in Claim 1.