NO753585L - - Google Patents

Description

The present invention relates to shampoo, and in particular

shampoos that contain conditioners.

It has been proposed to use various combinations of detergents and conditioners to produce a single phase, liquid shampoo which both cleanses and conditions human hair. Until now, however, it has been difficult to meet the conditions for a satisfactory liquid shampoo.

The properties desired in such a liquid preparation are that it should cleanse the hair, form a foam which is stable in the presence of grease but which is removed by rinsing the hair with water, leaves shiny hair and hair that is pleasant to the touch, has a suitable storage time and has a "conditioning effect" on the hair. With the term "conditioning effect" or "improvement in the condition of the hair" is meant an improvement in the manageability of the hair which is characterized by achieving one or more of the following results

(a) an improvement in combing of "moist" and

"dry" rinsed hair,

(b) an increase in the softness of the hair to the touch;

(c) a reduction of the tendency to tangle;

(d) a reduction in the hair's tendency to become statically charged

and

(e) an apparent increase in gloss..

It has been found that a single-phase detergent-conditioning system can be prepared by combining a cationic conditioning agent, which is a polymer of an imine, such as ethyleneimine or an alkylene iorln or an alkylated derivative of such a polymer, with a particular class of detergents .

According to the present invention, it is provided

a shampoo consisting of at least one detergent which is a sulfated one

aliphatic amine, amide or alkanolamide or a sulphated ethoxylated aliphatic amine, amide or alkanolamide containing on average up to 15 ethoxy groups per molecule and where the carbon chain of the allphatic group contains 8-18 carbon atoms and at least one imine polymer or an alkylated derivative of such a polymer in an aqueous environment.

The amine-based detergents used in the shampoos according to the present invention are true amphoteric in nature, while amide-

and alkanolamide-based detergents usually have a lower anionic character than conventional anionic detergents at a given pH.

Detergents derived from an amine, amide, alkanolamide or alkylated derivative thereof can be prepared by a sulphation or sulphation reaction. Usually a sulfamate reaction, e.g. the use of sulphamic acid or an alkyl sulphamic acid, better suited for the production of amine-based detergents, than amide- or alkanolamide-based detergents, since the mild sulfamate reaction is more generally applicable since the amines from which the detergents are derived are more labile bases than the corresponding amides or alkanol age. Amide- and alkanolamide-based detergents can be prepared using a sulphation reaction, e.g. with sulfur trioxide or chlorosulfonic acid. Under suitable reaction conditions, however, both reactions are applicable to all starting materials.

The amine-based detergents used in the shampoos according to the present invention have one of the following formulas

or

12

where R, R and R are an alkyl or alkenyl group containing 8-18 carbon atoms?

b is 0, or an integer from 1 to 15 and

X is a hydrogen atom, an ammonium or quaternary ammonium cation or the ion of an alkali metal or alkaline earth metal.

12

The groups R, R and R preferably contain 12-14 carbon atoms,

12

wherein the groups R and R in formula II are the same or different.

Examples of typical reactions that can be used in the production of amine-based detergents are as follows:

It will be seen that by using an alkyl-substituted sulfamic acid instead of sulfamic acid, an amine salt is obtained instead of an ammonium salt. The alkali metal and alkaline earth metal salts can be prepared, e.g. using cation exchangers by reacting a suitable ammonium salt with a strong base. A sodium salt can thus be prepared by treating an ammonium salt with sodium hydroxide.

Amide- and alkanolamide-based detergents used in the shampoos according to the present invention usually have one of the following formulas:

where R is an alkyl or alkenyl group containing 8-18 carbon atoms

b is 0, or an integer from 1 to 15}

X is a hydrogen atom, an ammonium or a quaternary aromonium cation, or the ion of an alkali or alkaline earth metal;

Y is a straight or branched alkoxy group containing 2 or more carbon atoms

a is 0 or lr

c is an integer from 1 to 14)

d is an integer from 1 to 14 h

and the sum of c and d is not greater than 15.

The group R preferably contains 12-14 carbon atoms. Examples of typical reactions that can be used for the production of amide- and alkanolamide-based detergents are as follows:

The transfer of sulphated detergent in the above reaction need not be complete. The percentage transfer is usually in the range from 50 to 100%. When the starting material is an alkanolamide, it is not necessary to remove unreacted starting material, since the unreacted alkanolamide will act as a foam stabilizer in the shampoo.

The chain length of the aliphatic® group in the detergent is usually that found in coconut oil or palm kernel oil, i.e. mainly a chain length of 12 carbon atoms, but the starting materials can also be of synthetic origin.

The content of ethoxy groups 1 the ethoxylated amine-, amide- and alkanolamide-based detergents used in the preparation according to the present invention can contain up to 15 ethoxylated units per mol. However, detergents are preferably used which have an average content of ethoxy groups from 1-6 units per mol. The desired average content of ethoxy groups can be achieved by mixing two or more detergents having different ethoxylate chain lengths.

The total content of detergent in the shampoo according to the present invention can vary according to the desired degree of foaming and cleaning that is desired. It will usually be in the range 5-35%, preferably 10-30% by weight of the total amount. Amine-, amide- or alkanolamide-based detergent can be partially replaced by an additional detergent, but such an additional detergent is preferably used in an amount that is less than 50% of the total detergent content. Additional detergents can be used, such as amphoteric detergents, e.g. alkyl betaines, such as lauryl betaines, amide oxides, such as alkyldimethylamine oxide, and imidazolines, or anionic detergents such as salts of lauryl ether sulfate, e.g. the sodium or monoisopropanolamine salts.

The imine polymers used in the preparations according to the present invention are indicated (J. Soc. Cos. Chem. 2_3, 593-603

(1972)) to have a structure as follows: where m has a value from 1 to 1500, preferably 5 to 100, and R 3 and R 4 each represent a hydrogen atom or an alkyl group containing 1-6 carbon atoms. Be can usually be prepared by polymerizing an imine of the formula: In practice, branching takes place to a large extent in the polymerization of imines and primary, secondary and tertiary nitrogen atoms will be present in the molecule. The imine polymers can be alkoxylated by reaction with an alkylene oxide.

The cationic nature of the imine polymer increases as the acidity of the environment increases. In the above literature reference, it is stated that at pH 8.0, pH 6.0 and pH 4.0 the percentage of nitrogen atoms in polyethyleneimine that have a positive charge is 25%, 33% and 50% respectively.

Examples of ethylene imine polymers manufactured by Dow Chemical Co. (Midland Mich 48640) is accordingly a Trademark

According to the present invention, the imine polymer used as a cationic conditioning agent can be used in an amount of active ingredient from 0.05 - 2.5% by weight of the total amount, preferably 0.1 - 1.0% by weight.

Cationic conditioners are non-toxic to human hair, an effect believed to be due to electrostatic attraction. When using the preparation according to the invention, the conditioning agent is adsorbed as a thin, continuous film over the hair so that a conditioning effect is obtained on the hair. The adsorption of the cationic conditioner by this mechanism provides a complete or almost complete coverage of each hair with a thin film of conditioner. The film or conditioner can be as thin as a monolayer and still exert a conditioning effect on the hair.

In addition to the conditioning effect, polyethyleneimine has a strong anti-microbial effect against a number of organisms. In particular, it has been shown that polyethyleneimity has a strong inhibitory effect against the organism P. ovale, which is indicated to be associated with dandruff. Other antimicrobial agents, such as 2,4,4*trichloro-2-hydroxy-diphenyl ether ("Irgasan DP 300" - Ciba-Geigy), trichlorocarbanilide, cetyltrimethylarammonium chloride, benzalkonium chloride, heavy metal salts of 2-pyridinethiol-1-oxide or colloidal sulfur may is added to the shampoo according to the present invention.

Polyethyleneimine has a strong ochelating effect

and will form complexes with some compounds containing metal ions, such as heavy metal salts of 2-pyridinethiol-1~oxide (pyrithion). The zinc salt of pyrithione is e.g. sparingly soluble in water, but a complex of zinc pyrithione with an excess of polyethyleneimine (molecular weight 600) gives a clear, aqueous solution which is soluble in the shampoo according to the present invention, and which gives a clear shampoo which does not precipitate solid material on centrifugation. The preferred heavy metal salt of pyrithione is the zinc salt and the shampoos according to the present invention can contain up to 0.5% by weight of this salt. Other suitable heavy metal salts include cobalt, manganese and nickel salts.

The preferred pH of the shampoo will depend on the formulation* Sn reduction in pH increases the cationic nature of the shampoo. The preferred pH of the shampoo will therefore be as low as possible, provided that the resulting preparation then has the necessary stability, and meets the normal safety requirements for shampoos. pH of polyethyleneimine-containing preparations

which does not contain zinc pyrithione is preferably in the area

4-10. However, the preferred pK of the preparation may vary

according to the molecular weight of the polyethyleneimine used. How about it

e.g. if a low molecular weight polyethyleneimine is used, such as "PEI 6", the preferred pH range is 5-7, but if one uses long-chain polymers, such as "PEI 600" and long-chain alkylated polymers such as "PEI 600E " is the preferred pH range of 7-9.

In shampoos containing a complex of zinc pyrithione/polyethyleneimine, the preferred pH is again as low as possible, within the constraints imposed by product stability and safety, and is usually in the range of 4-10*The pH value that provides a suitable clear , homogeneous mixture is, however, dependent on, among other things, the detergent system used.

In mixtures such as contains the sodium salt of sulfated

1.9 mol ethoxylated, coconut fatty acid monoethanolamide and coconut oil/dimethyl betaine detergents, the preferred pH range of the mixtures is 8.6-9, while that for mixtures containing a detergent mixture containing the ammonium salt of sulfated

coconut oil, the sodium salt of sulfated, 6-rool ethoxylated coconut oil amine, and coconut oil dimethyl betaln is preferably a pH range of 5-7.

.in

The pH of the shampoo can be adjusted to the desired value by adding acid, and the preferred acids are phosphoric acid, hydrochloric acid, acetic acid, sulfuric acid, tartaric acid and sulfuric acid, or by adding a base, such as sodium hydroxide or triethanolamine or monoisopropanolamine.

Further cationic conditioning agents can be added to the shampoos according to the present invention 1 in an amount of 0.1-10% by weight, preferably 0.1-2.5% by weight, of the total amount.

The additional cationic conditioning agent may be a mono- or poly-cationic compound or a mixture thereof.

Examples of mono-cationic compounds that can be used in the shampoos according to the present invention are: alkyltrimethylammonium halides,

N-alkylpyridinium halides,

N-alkylisoquinolinium halides,

dialkyldimethylamaronium halides,

alkylaryldimethylammonium halides

fatty acid aminoalkylamines ("Sapamines") and alkylbenzylhydroxyethyliraidazolinium chloride.

Mixtures of such compounds can also be used. To improve the solubility of such mono-cationic compounds, the nitrogen groups can be ethoxylated. This is particularly important for dialkyl quaternary ammonium salts which have low solubility in an aqueous environment.

Examples of typical polycationic compounds that can be used in the shampoos according to the present ppp invention are: high molecular weight aminoethyl acrylate/phosphate/acrylate copolymer sold under the trademark "CATREX" (formerly known as "RESYN 78-3510") (National Adhesives Limited).

quaternized vinylpyrrolidone copolymers are sold under the trade name "GAFQUAT 734", "755", "750" or "759" by G.A.F. Limited,

low molecular weight condensation product of adipic acid, diethylenetriamine polyamide and epichlorohydrin sold under the trademark "DELSETTE", e.g. "DELSETTE 101" or "201" by Hercules Limited and

the quaternary nitrogen-containing cellulose ether is sold under the trademark "POLYMER JR" by Union Carbide Corporation. Mixtures of such compounds can also be used. ("RESYN", "CATREX", "GAFQUAT", "DELSETTE" and "POLYMER JR" are trademarks).

The shampoos according to the present invention may contain additives that are common in shampoos today, provided that such additives do not significantly interfere with the adsorption mechanism of the cationic conditioning agent on the hair and do not significantly reduce the effect of any antimicrobial agent that is present.

Non-ionic foam stabilizers which are usually used in shampoos can be added to the shampoo according to the present invention. Typical examples of foam stabilizers are amine oxides, such as coconut oil dimethylamine oxide, alkyl betaines, such as coconut oil dimethyl betaine, alkanolamides, such as monoethanolamide and diethanolamide of coconut fatty acids or ethoxylated derivatives thereof. The foam stabilizers are usually added to the shampoo according to the present invention in an amount of 1-5% by weight based on the total weight.

Thickening agents, such as simple salts or ethoxylated fatty acids or diluents, such as glycols, poly-glycols or polyalkylene glycols can be added to the shampoos according to the present invention.

Additional additives such as protein hydrolysates, lanolin and derivatives thereof, herbal or balsaar extracts, vitamins, vegetable oils, dyes, perfumes and preservatives, such as formalin or dodecylguanidih, can be added without impairing the basic properties of the shampoos.

Mother-of-pearl or opacity agents can also be added, e.g. ethylene glycol monostearate, ethylene glycol distearate, alkaline earth soaps or fatty acid alcohols.

The following examples illustrate the present invention.

The percentage is calculated on a weight basis for the total weight of the shampoo if nothing else is stated.

Example 1

The following materials are mixed together at room temperature in a mixing chart

The pH of the mixture was adjusted to 5.2 by adding citric acid. A clear, liquid shampoo was obtained. (a) The conversion to sulphate in the manufacture of this detergent was 75% and the 30% aqueous solution thus contains 24% sulphate and 6% unreacted, 1.9 mol ethoxylated, coconut fatty acid monoethanolamide.

Example 2

The following materials were mixed together at room temperature in a mixing vessel

The pH of the mixture was adjusted to 5.5 by adding citric acid. You got a clear, liquid shampoo. (b) The transfer to this detergent was 75%.

Example 3.

The following materials were mixed together at room temperature in eight mixing vessels:

The pH of the mixture was adjusted to 8.2 with citric acid.

You got a clear, liquid shampoo.

The shampoos which were prepared in examples 1, 2 and 3 were tested in individual trials against a shampoo which was marketed with a conditioning effect, by head trials and uncombed hair and were visually compared after final rinsing. The half heads treated with a shampoo from one of Examples 1, 2 or 3 appear to be combed through, while the half heads treated with the comparison shampoo were visibly tangled. It turned out that the hair had improved dry and wet malleability with the shampoo according to the present invention and that tangling was practically eliminated. Moreover, hair treated with the shampoo according to the invention was clean and soft to the touch and had a good shine.

Example 4

The pH of the mixture was adjusted to 5.3 by adding citric acid and a clear liquid shampoo was obtained.

Example 5

In preparing the following mixtures, "Irgasan DØ 300" and coconut fatty acid dlethanolamide were mixed together and heated until a clear solution was obtained and then mixed with the remaining ingredients in a mixing vessel at room temperature.

The pH of the mixture was adjusted to 5.3 by adding citric acid, and a clear, liquid shampoo was obtained" The formulation was tested for bacteriostatic action and the result of the average minimum inhibitory dilution against three organisms was as follows"

These results illustrate the specific and potent inhibitory action of "PEI 6" against P. ovale, an organism associated with dandruff. "IrgasanDP 300" is weak against this organism, but a combination of the two components gives eli a very powerful, broad spectrum of antimicrobial action.

A further bacteriological test was carried out to investigate the substantivity. A calf cheek slice was moistened

in a diluted solution of the shampoo for 15 minutes at 37°C. It was then removed, rinsed well, placed on an agar plate and incubated. The inhibition zones were measured in mm and gave the following results:

The results confirm the substance of the antimicrobial active ingredient in the shampoo.

Example 6

In preparing the following mixture, zinc pyrithione was mixed with "PEI 6" and some water. The clear solution

which was obtained was then mixed with the remaining ingredients in a simple mixer:

The pH was adjusted to 8.6 by adding hydrochloric acid.

The resulting shampoo was a clear mixture which did not deposit any particulate matter during storage or after prolonged centrifugation.

This product was tested for bacteriostatic effect in a similar way to 1 example 5. The results are as follows Average minimum inhibitory dilution

Calfskin, inhibiting zone in mm

The results show a strong inhibitory effect against P*ovale and a high degree of substantivity.

The mixture of Example 6 was also subjected to an anti-dandruff test on a panel consisting of 24 people. The procedure was to use a panel consisting of 4 trained observers to visually determine the level of dandruff of the subjects each week before the use of shampoo, and to determine the degree of harsh treatment measured according to a random scale. One control shampoo was used for the first 5 weeks © of the experiment and then the shampoo in example 6 was used for the next 10 weeks. The reduction in dandruff levels was marked and reached a maximum after 8 weeks of treatment with the shampoo in Example 6. The reduction in dandruff was greater than that achieved in a parallel trial conducted in a similar manner using a zinc pyrithione shampoo available at market and which contains four times the zinc pyrithione level (1%) in suspension form.

Example 7

The following mixture was prepared in a similar manner to Example 6.

The pK of the mixture was adjusted to 8.55 by adding hydrochloric acid. The resulting shampoo was a clear mixture that did not deposit any particulate matter during storage or after prolonged centrifugation.

The product was tested for bacteriostatic effect in a similar way as described in example 5.

The achieved results varied

Average minimum inhibitory dilution Calfskin, inhibitory zone in mm

Example 6

The following mixture was prepared in a similar manner to Example 6.

The pH of the mixture was adjusted to 6.4 by adding citric acid. The resulting liquid shampoo was ready.

Examples 9-11

Three mixtures containing the indicated components were prepared:

The mixtures in examples 9-11 were prepared in a similar way as described in example 6.

The pH of each of these was adjusted to 8.7 by adding sulfuric acid. All provided clear shampoos that were tested for anti-inflammatory activity as indicated in Example 5. They obtained results whose

Average minimum inhibitory dilution

Calfskin, inhibiting zone in mm

Example 12

A shampoo was produced in which the desired average ethoxylated chain length in the ethoxylated amine sulphate detergents was achieved by mixing two detergents having different ethoxylated chain lengths. The ingredients in the shampoo were?

The ingredients were mixed together in a simple mixer at room temperature.

The pH of the mixture was adjusted to 7.1 by adding sulfuric acid.

Claims (11)

1. Shampoo containing at least one detergent and a cationic conditioner in an aqueous environment, characterized in that the detergent is sulphated aliphatic amine, amide or alkanolamide or a sulphated, ethoxylated aliphatic amine, amide or alkanolamide containing on average up to 15 ethoxy groups per mol and where the carbon mass of the aliphatic group contains 8-18 carbon atoms and that the cationic conditioning agent is an imln- polymer© is an alkylated derivative of such a polymer. 2. Shampoo as specified in claim 1, characterized in that the detergent is an amine-based detergent of the formula: or where R, R and R independently of each other are an alkyl or alkenyl group containing 8-18 carbon atoms b is 0, or an integer from 1 to 15, and X is a hydrogen atom, an ammonium or quaternary ammonium cation or the ions of an alkali metal or alkaline earth metal 3. Shampoo as specified in claim 1, characterized in that the detergent is an amide- or alkanolamide-based wash mean of the formula: or where R is an alkyl or alkenyl group containing 8-18 carbon atoms; b is O or that whole number from 1 to 15ji X is a hydrogen atom, an ammonium or quaternary ammonium cation, or the ion of an alkali or alkaline earth metal Y is a straight or branched alkoxy group containing 2 or more carbon atoms, a is 0 or 1, c is an integer from 1 to 14, d is an integer from 1 to 14, as the sum of c and d is not greater than 15. 4. Shampoo as stated in any of the preceding claims, characterized in that the average ethoxylated chain length of the detergent is 1-6 units per mol. 5. Shampoo as specified in any of the preceding claims, characterized in that the average ethoxylated chain length of the detergent is obtained by mixing two or more detergents which have different ethoxylated © chain lengths. 6. Shampoo as stated in any of the preceding claims, characterized in that it also contains an additional detergent, the additional detergent constituting less than 50% by weight of the total detergent. 7. Shampoo as stated in any of the preceding claims, characterized in that the imine polymer is a polymerization product of an imine of the formula which has a degree of polymerization of 1-150 0, and where R 3 and R<4> independently of each other mean a hydrogen atom or an alkyl group containing 1-6 carbon atoms. 8. shampoo as stated in claim 7, characterized in that the degree of polymerization of the imine polymer is 5-100. 9. Shampoo as specified in any of the preceding claims, characterized in that the imine polymer or the alkylated derivative thereof is present in an amount of 0.05-2.5% by weight of the total amount. 10. Shampoo as stated in any of the preceding claims, characterized in that the imine polymer is complexly bound to a heavy metal salt of 2-pyridinethiol-1-oxide. 11. Shampoo as stated in any of the preceding claims, characterized in that a further cationic conditioning agent is present in an amount of 0.1-10% by weight. of the total amount.