EP4619385A2

EP4619385A2 - Process for the preparation of piroctone, including crystallization or precipitation, piroctone particles and process for the preparation of piroctone olamine

Info

Publication number: EP4619385A2
Application number: EP23805050.4A
Authority: EP
Inventors: Anil Kumar Soni; Raghuveer Tallam; Pavan Kumar DUDDILLA; Sai Dinesh YENAMULA; Shantanu SATHE
Original assignee: Clariant International Ltd
Current assignee: Clariant International Ltd
Priority date: 2022-11-16
Filing date: 2023-11-13
Publication date: 2025-09-24
Also published as: WO2024104987A2; WO2024104987A3; CN120457108A

Abstract

The present invention relates to a process for the crystallization or precipitation of piroctone, comprising the following steps: a) Dissolving a piroctone-containing product in a solvent; b) Cooling the solution; and c) Isolating crystallized or precipitated piroctone.

Description

PROCESS FOR THE CRYSTALLIZATION OR PRECIPITATION OF PIROCTONE

The invention relates to a process for the crystallization or precipitation of piroctone as well as to piroctone particles having a certain particle size. The invention also relates to the use of the piroctone for the manufacture of a cosmetic composition, a cosmetic composition comprising the piroctone, and the use of the piroctone as an anti-dandruff agent or as a preservative.

Preservation of cosmetic formulations and household formulations extends their shelf life and therefore provides greater value for money for consumers. Furthermore, preservatives prevent consumers from distributing microbes around their home or on themselves and hence provide health benefits. Anti-microbial actives are well- described in the art and there are many available that provide excellent performance.

Piroctone Olamine, also known as Octopirox® (Clariant) and as piroctone ethanolamine, is a compound used in the treatment of fungal infections. The chemical name for Piroctone Olamine is the monoethanolamine salt of 1 hydroxy-4- methyl-6-(2,4,4-trimethylpentyl)-2(1 H)-pyridone. Hence, Piroctone Olamine is the ethanolamine salt of the hydroxamic acid derivative piroctone.

Piroctone Olamine is often used in anti-dandruff shampoos as a safe alternative to the commonly used compound zinc pyrithione.

GB1440975, EP0158481 , and W02006/081969, among others, describe the use of Piroctone Olamine as an anti-dandruff agent and/or as a preservative.

Nevertheless, there is a desire for improved preservation and anti-fungal systems. In particular, there is a desire for reducing the concentration of such systems - but this requires improved efficacy to ensure that sufficient microbial growth is inhibited. Consumers have generally become more conscious about the content of cosmetic and household products, and they desire reduced levels of ‘chemicals’, particularly those that may have a reputation for inhibiting the growth of microorganisms. With the foregoing in mind, there remains a need for more efficacious preservation and anti-fungal substances, which meet present performance requirements as well as modern consumer desires and expectations.

The olamine counter ion in piroctone olamine accounts for approximately 20% of the overall weight of piroctone olamine but does not contribute to its anti-dandruff activity. Piroctone as such does not have an olamine counter ion and therefore the activity to weight ratio is higher than in piroctone olamine.

However, while piroctone olamine is often used in cosmetic compositions such as shampoos, there is to the best of our knowledge no market example (based on Mintel search) containing piroctone, although it is even listed as allowed preservative in Annex V of the Regulation (EC) No 1223/2009 of the European Parliament. Using piroctone in cosmetic compositions such as shampoos is very challenging. In particular, it is very challenging to dissolve piroctone in these formulations.

Surprisingly, it has now been found that piroctone can be isolated and purified by crystallization or precipitation. Such crystallization or precipitation provides piroctone having a desired particle size.

Advantageously, the process of the present invention provides piroctone in good yields and high purities. The piroctone of the present invention has a desired particle size. In particular, the dgo value is low. Such piroctone is soluble in surfactantcontaining formulations.

A further advantage of the process of the present invention is that the desired particle size can be achieved by means of a chemical process, directly using the crude product obtained by a process for the preparation of piroctone. A mechanical process like grinding or milling followed by sieving is not necessary. Hence, yield losses due to an additional process can be avoided.

An advantage of piroctone is that there is a better activity to weight ratio than for piroctone olamine, i.e. more efficacy per molecular weight of active. The olamine counter ion in piroctone olamine accounts for approximately 20% of the overall mass of piroctone olamine but does not contribute to its anti-dandruff activity.

Piroctone as used herein is also known as 1 -hydroxy-4-methyl-6-(2,4,4- trimethylpentyl)-2(1 H)-pyridone and refers to a compound of the following formula:

Pyron as used herein is also known as 1-hydroxy-4-methyl-6-(2,4,4-trimethylpentyl)- 2(1 H)-pyrone and refers to a compound of the following formula:

In relation to the particle size distribution measures used herein, dso, d(50) or D50, the median, is defined as the diameter where half of the population lies below this value. Similarly, 10 percent of the population lies below the dio, d(10) or D10 diameter and 90 percent of the population lies below the dgo, d(90) or D90 diameter. If not stated otherwise, the dso, dio, dgo values are based on a volume distribution.

The process of the invention comprises the following step a): Dissolving a piroctone- containing product in a solvent. According to the invention, the piroctone-containing product used in step a) comprises piroctone.

In preferred embodiments, the piroctone-containing product used in step a) comprises at least 10 wt.-%, preferably at least 20 wt.-%, more preferably at least 30 wt.-%, more preferably at least 40 wt.-%, even more preferably at least 50 wt.-%, even more preferably at least 55 wt.-%, particularly preferably at least 60 wt.-%, of piroctone, based on the total weight of the piroctone-containing product.

In preferred embodiments, the piroctone-containing product used in step a) comprises at least 70 wt.-%, preferably at least 80 wt.-%, more preferably at least 90 wt.-%, even more preferably at least 95 wt.-%, particularly preferably at least 98 wt.- %, of piroctone, based on the total weight of the piroctone-containing product.

The piroctone-containing product may, for example, be a crude product obtained by a process for the preparation of piroctone. In a preferred embodiment, the piroctone- containing product is a crude product obtained by a process which comprises reacting pyron with hydroxylamine or a hydroxylammonium compound. Accordingly, the piroctone-containing product may, for example, also comprise one or more byproducts or side-products of such a process, or pyron.

Alternatively, the piroctone-containing product may, for example, be relatively pure or pure piroctone, i.e. essentially consist of or consist of piroctone. It may still be useful to subject such a piroctone to the process of the present invention because it may change the particle size distribution of the piroctone.

Preferably, the solvent in step a) is selected from heptane, hexane, cyclohexane, methylcyclohexane, dimethylcyclohexane, toluene, benzene, methylene chloride, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tertbutanol, tert-amyl alcohol, dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, acetonitrile, 2-aminopyridine, methyl tert-butyl ether, dibutyl ether, diisopropyl ether, water, and mixtures thereof. More preferably, the solvent in step a) is selected from heptane, hexane, cyclohexane, methylcyclohexane, dimethylcyclohexane, methanol, ethanol, n- propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, tert-amyl alcohol, methyl tert-butyl ether, dibutyl ether, diisopropyl ether, water, and mixtures thereof.

Even more preferably, the solvent in step a) is selected from heptane, hexane, cyclohexane, methylcyclohexane, dimethylcyclohexane, methyl tert-butyl ether, dibutyl ether, diisopropyl ether, and mixtures thereof. Particularly preferably, the solvent in step a) is heptane.

In a preferred embodiment, the solvent in step a) is a mixture of an alcohol and water. Preferably, the alcohol is selected from methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, tert-amyl alcohol, and mixtures thereof. In a particularly preferred embodiment, the solvent in step a) is a mixture of isopropanol and water. Preferably, the solvent comprises at least 30 wt.-% of the alcohol (preferably isopropanol) and up to 70 wt.-% of water, based on the total weight of the solvent. More preferably, the solvent comprises from 40 to 70 wt.-% of the alcohol (preferably isopropanol) and from 30 to 60 wt.-% of water, based on the total weight of the solvent. Particularly preferably, the solvent comprises from 50 to 60 wt.-% of the alcohol (preferably isopropanol) and from 40 to 50 wt.-% of water, based on the total weight of the solvent.

In preferred embodiments, in step a) at least 50 ml, preferably at least 100 ml, more preferably at least 300 ml, particularly preferably at least 500 ml, of solvent is used per 100 g of the piroctone-containing product. In one embodiment, in step a) at least 1000 ml of solvent is used per 100 g of the piroctone-containing product.

In preferred embodiments, in step a) 50 to 1000 ml, preferably 100 to 900 ml, more preferably 300 to 800 ml, particularly preferably 500 to 750 ml, of solvent is used per 100 g of the piroctone-containing product. In preferred embodiments, in step a) 400 to 700 ml, preferably 450 to 650 ml, more preferably 450 to 600 ml, particularly preferably 500 to 600 ml, of solvent is used per 100 g of the piroctone-containing product. In one embodiment, in step a) 1000 to 1500 ml of solvent is used per 100 g of the piroctone-containing product.

In preferred embodiments, the piroctone-containing product in step a) is dissolved in the solvent at a temperature in the range of from 30 to 100 °C, preferably from 40 to 90 °C, more preferably from 50 to 80 °C, particularly preferably from 60 to 80 °C. In preferred embodiments, the piroctone-containing product in step a) is dissolved in the solvent at a temperature in the range of from 55 to 85 °C, preferably from 60 to 80 °C, more preferably from 65 to 80 °C, particularly preferably from 70 to 75 °C.

The process of the invention comprises the following step b): Cooling the solution.

In one embodiment, the solution in step b) is cooled to a temperature in the range of from -10 to 80 °C. In preferred embodiments, the solution in step b) is cooled to a temperature in the range of from -5 to 50 °C, preferably from 0 to 35 °C, more preferably from 0 to 25 °C, particularly preferably from 0 to 20 °C. In preferred embodiments, the solution in step b) is cooled to a temperature in the range of from - 5 to 20 °C, preferably from 0 to 15 °C, more preferably from 0 to 10 °C, particularly preferably from 0 to 5 °C. In preferred embodiments, the solution in step b) is cooled to a temperature in the range of from 0 to 35 °C, preferably from 5 to 30 °C, more preferably from 10 to 25 °C, particularly preferably from 15 to 20 °C.

The process of the invention comprises the following step c): Isolating crystallized or precipitated piroctone.

In preferred embodiments, the crystallized or precipitated piroctone is isolated by filtration. Preferably, filtration is followed by washing with a solvent (preferably the solvent used in step a)) and drying.

In preferred embodiments, the piroctone-containing product used in step a) is prepared by reacting pyron with hydroxylamine or a hydroxylammonium compound, preferably a hydroxylammonium compound. In one embodiment, pyron is reacted with hydroxylamine. Hydroxylamine can, for example, be used in the form of an aqueous solution. Hydroxylamine is, for example, commercially available as a 50% aqueous solution.

In a preferred embodiment, pyron is reacted with a hydroxylammonium compound. Hydroxylammonium compounds are particularly preferred. Suitable hydroxylammonium compounds are known to a person skilled in the art. Preferred hydroxylammonium compounds are selected from hydroxylammonium sulfate, hydroxylammonium chloride, hydroxylammonium acetate, hydroxylammonium phosphate, hydroxylammonium nitrate, hydroxylammonium perchlorate, hydroxylammonium oxalate, hydroxylammonium hydrogen sulfate, hydroxylammonium 4 n ethyl benzenesulfonate and hydroxylammonium bromide. More preferred hydroxylammonium compounds are selected from hydroxylammonium sulfate, hydroxylammonium chloride and hydroxylammonium acetate. Even more preferred hydroxylammonium compounds are selected from hydroxylammonium sulfate and hydroxylammonium chloride. A particularly preferred hydroxylammonium compound is hydroxylammonium sulfate. Another particularly preferred hydroxylammonium compound is hydroxylammonium chloride.

Preferably, the molar ratio of pyron to hydroxylamine equivalents is from 1 .0:1.0 to 1.0:4.0, more preferably from 1.0: 1.8 to 1.0:3.0, even more preferably from 1.0:2. O to 1 .0:2.6, particularly preferably from 1 .0:2.0 to 1 .0:2.4, for example 1.0:2.2.

In a preferred embodiment, the molar ratio of pyron to the hydroxylammonium compound is from 1 .0:0.5 to 1 .0:2.0, more preferably from 1 .0:0.9 to 1 .0:1 .5, even more preferably from 1 .0:1 .0 to 1 .0:1 .3, particularly preferably from 1.0: 1.0 to 1.0: 1.2, for example 1 .0:1 .1 . Such molar ratios are preferred, for example, when hydroxylammonium sulfate is used as the hydroxylammonium compound.

In another preferred embodiment, the molar ratio of pyron to hydroxylamine or the hydroxylammonium compound is from 1.0: 1.0 to 1.0:4.0, more preferably from 1.0: 1.8 to 1.0:3.0, even more preferably from 1.0:2.0 to 1.0:2.6, particularly preferably from 1.0:2.0 to 1.0:2.4, for example 1.0:2.2. Such molar ratios are preferred, for example, when hydroxylammonium chloride or hydroxylammonium acetate is used as the hydroxylammonium compound.

In preferred embodiments, pyron is reacted with hydroxylamine or the hydroxylammonium compound in the presence of a base. In one embodiment, pyron is reacted with hydroxylamine in the presence of a base. In another embodiment, pyron is reacted with hydroxylamine in the absence of a base. In a preferred embodiment, pyron is reacted with the hydroxylammonium compound in the presence of a base.

Suitable bases are known to a person skilled in the art. Examples of suitable bases are metal carbonates, metal hydrogen carbonates, or metal hydroxides, such as alkali metal carbonates, alkali metal hydrogen carbonates, alkali metal hydroxides, alkaline earth metal carbonates, alkaline earth metal hydrogen carbonates, or alkaline earth metal hydroxides. Preferred bases are selected from alkali metal carbonates, alkali metal hydrogen carbonates, alkali metal hydroxides, and mixtures thereof. More preferred bases are selected from alkali metal carbonates, alkali metal hydrogen carbonates, and mixtures thereof. Even more preferred bases are selected from alkali metal carbonates.

Examples of suitable bases are lithium carbonate, sodium carbonate, potassium carbonate, cesium carbonate, lithium hydrogen carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, cesium hydrogen carbonate, lithium hydroxide, sodium hydroxide, potassium hydroxide, cesium hydroxide, calcium carbonate, magnesium carbonate, barium carbonate, nickel carbonate, zirconium carbonate, calcium hydroxide, magnesium hydroxide, barium hydroxide, nickel hydroxide, or zirconium hydroxide. Preferred bases are selected from lithium carbonate, sodium carbonate, potassium carbonate, lithium hydrogen carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, sodium hydroxide, potassium hydroxide, and mixtures thereof. More preferred bases are selected from lithium carbonate, sodium carbonate, potassium carbonate, lithium hydrogen carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, and mixtures thereof. Even more preferred bases are selected from lithium carbonate, sodium carbonate, potassium carbonate, and mixtures thereof. Also even more preferred bases are selected from sodium carbonate, sodium hydrogen carbonate, and mixtures thereof. A particularly preferred base is sodium carbonate.

Preferably, the molar ratio of hydroxylamine equivalents to base equivalents is from 1 .0:0.5 to 1 .0:3.0, more preferably from 1 .0:0.8 to 1 .0:2.0, even more preferably from 1 .0:1 .0 to 1 .0:1.5, even more preferably from 1 .0:1.0 to 1 .0:1.2, particularly preferably from 1.0:1.0 to 1.0:1.1 , for example 1.0:1.0.

In a preferred embodiment, the molar ratio of the hydroxylammonium compound to the base is from 1 .0:0.5 to 1.0:3.0, more preferably from 1 .0:0.8 to 1.0:2.0, even more preferably from 1.0: 1.0 to 1.0: 1.5, even more preferably from 1.0: 1.0 to 1.0: 1.2, particularly preferably from 1 .0: 1.0 to 1.0: 1 .1 , for example 1 .0: 1 .0. Such molar ratios are preferred, for example, when hydroxylammonium sulfate is used as the hydroxylammonium compound and an alkali metal carbonate (for example sodium carbonate) is used as the base.

In preferred embodiments, pyron is reacted with hydroxylamine or the hydroxylammonium compound in the presence of a solvent. Suitable solvents are known to a person skilled in the art.

Preferred solvents are selected from organic solvents, water, and mixtures thereof. Preferred organic solvents are selected from heptane, hexane, cyclohexane, methylcyclohexane, dimethylcyclohexane, toluene, benzene, methylene chloride, methanol, ethanol, isopropanol, tert-butanol, tert-amyl alcohol, dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, acetonitrile, 2-aminopyridine, and mixtures thereof. More preferred organic solvents are selected from heptane, hexane, cyclohexane, methylcyclohexane, toluene, 2-aminopyridine, and mixtures thereof. Even more preferred organic solvents are selected from heptane, toluene, and mixtures thereof. A particularly preferred organic solvent is heptane. Another particularly preferred organic solvent is toluene. In a preferred embodiment, the solvent is a mixture of an organic solvent and water. In a more preferred embodiment, the solvent is a mixture of an organic solvent and water, wherein the organic solvent is selected from heptane, hexane, cyclohexane, methylcyclohexane, dimethylcyclohexane, toluene, benzene, methylene chloride, methanol, ethanol, isopropanol, tert-butanol, tert-amyl alcohol, dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, acetonitrile, 2-aminopyridine, and mixtures thereof. In an even more preferred embodiment, the solvent is a mixture of an organic solvent and water, wherein the organic solvent is selected from heptane, hexane, cyclohexane, methylcyclohexane, toluene, 2-aminopyridine, and mixtures thereof. In an even more preferred embodiment, the solvent is a mixture of an organic solvent and water, wherein the organic solvent is selected from heptane, toluene, and mixtures thereof. In a particularly preferred embodiment, the solvent is a mixture of an organic solvent and water, wherein the organic solvent is heptane. In another particularly preferred embodiment, the solvent is a mixture of an organic solvent and water, wherein the organic solvent is toluene.

Preferably, the solvent comprises at least 80 wt.-%, more preferably at least 90 wt.- %, even more preferably at least 95 wt.-%, particularly preferably at least 98 wt.-%, of an organic solvent, based on the total weight of the solvent. In a preferred embodiment, the solvent comprises at least 80 wt.-%, more preferably at least 90 wt.- %, even more preferably at least 95 wt.-%, particularly preferably at least 98 wt.-%, of heptane or toluene, based on the total weight of the solvent.

Preferably, pyron is reacted with hydroxylamine or the hydroxylammonium compound at a temperature of 50 to 120 °C, more preferably 60 to 100 °C, even more preferably 70 to 90 °C, particularly preferably 80 to 90 °C.

Preferably, pyron is reacted with hydroxylamine or the hydroxylammonium compound for at least 4 hours, more preferably at least 8 hours, even more preferably at least 12 hours, particularly preferably at least 15 hours. For example, pyron is reacted with hydroxylamine or the hydroxylammonium compound for 8 to 24 hours, preferably 12 to 20 hours, particularly preferably 15 to 18 hours. In preferred embodiments, the crystallized or precipitated piroctone has a dgo of 250 pm or less, preferably 200 pm or less, more preferably 150 pm or less, particularly preferably 100 pm or less. In preferred embodiments, the crystallized or precipitated piroctone has a dgo in the range of from 30 to 250 pm, preferably from 40 to 200 pm, more preferably from 50 to 150 pm, particularly preferably from 60 to 100 pm.

In more preferred embodiments, the crystallized or precipitated piroctone has a dgo of 90 pm or less, preferably 85 pm or less. In more preferred embodiments, the crystallized or precipitated piroctone has a dgo in the range of from 65 to 90 pm, preferably from 70 to 90 pm, more preferably from 70 to 85 pm, particularly preferably from 75 to 85 pm.

In preferred embodiments, the crystallized or precipitated piroctone has a dso of 90 pm or less, preferably 80 pm or less, more preferably 75 pm or less, particularly preferably 70 pm or less. In preferred embodiments, the crystallized or precipitated piroctone has a dso in the range of from 10 to 90 pm, preferably from 15 to 80 pm, more preferably from 20 to 75 pm, particularly preferably from 25 to 70 pm.

In more preferred embodiments, the crystallized or precipitated piroctone has a dso of 60 pm or less, preferably 50 pm or less, more preferably 40 pm or less, particularly preferably 35 pm or less. In more preferred embodiments, the crystallized or precipitated piroctone has a dso in the range of from 15 to 60 pm, preferably from 20 to 50 pm, more preferably from 25 to 40 pm, particularly preferably from 28 to 35 pm.

In preferred embodiments, the crystallized or precipitated piroctone has a d of 30 pm or less, preferably 25 pm or less, more preferably 20 pm or less, particularly preferably 15 pm or less. In preferred embodiments, the crystallized or precipitated piroctone has a dw in the range of from 2 to 30 pm, preferably from 3 to 25 pm, more preferably from 4 to 20 pm, particularly preferably from 5 to 15 pm.

In more preferred embodiments, the crystallized or precipitated piroctone has a d of 12 pm or less, preferably 10 pm or less. In more preferred embodiments, the crystallized or precipitated piroctone has a dio in the range of from 4 to 12 pm, preferably from 5 to 10 pm.

The present invention also relates to crystallized or precipitated piroctone obtained by the process of the present invention.

The present invention also relates to piroctone particles having a dgo of 250 pm or less. In preferred embodiments, the piroctone particles have a dgo of 200 pm or less, preferably 150 pm or less, particularly preferably 100 pm or less. In preferred embodiments, the piroctone particles have a dgo in the range of from 30 to 250 pm, preferably from 40 to 200 pm, more preferably from 50 to 150 pm, particularly preferably from 60 to 100 pm.

In more preferred embodiments, the piroctone particles have a dgo of 90 pm or less, preferably 85 pm or less. In more preferred embodiments, the piroctone particles have a dgo in the range of from 65 to 90 pm, preferably from 70 to 90 pm, more preferably from 70 to 85 pm, particularly preferably from 75 to 85 pm.

In preferred embodiments, the piroctone particles have a dso of 90 pm or less, preferably 80 pm or less, more preferably 75 pm or less, particularly preferably 70 pm or less. In preferred embodiments, the piroctone particles have a dso in the range of from 10 to 90 pm, preferably from 15 to 80 pm, more preferably from 20 to 75 pm, particularly preferably from 25 to 70 pm.

In more preferred embodiments, the piroctone particles have a dso of 60 pm or less, preferably 50 pm or less, more preferably 40 pm or less, particularly preferably 35 pm or less. In more preferred embodiments, the piroctone particles have a dso in the range of from 15 to 60 pm, preferably from 20 to 50 pm, more preferably from 25 to 40 pm, particularly preferably from 28 to 35 pm.

In preferred embodiments, the piroctone particles have a dio of 30 pm or less, preferably 25 pm or less, more preferably 20 pm or less, particularly preferably 15 pm or less. In preferred embodiments, the piroctone particles have a dio in the range of from 2 to 30 m, preferably from 3 to 25 pm, more preferably from 4 to 20 pm, particularly preferably from 5 to 15 pm.

In more preferred embodiments, the piroctone particles have a dio of 12 pm or less, preferably 10 pm or less. In more preferred embodiments, the piroctone particles have a d in the range of from 4 to 12 pm, preferably from 5 to 10 pm.

In preferred embodiments, the piroctone particles are obtained by the process of the present invention.

The present invention also relates to a process for the preparation of piroctone, comprising the following steps:

1 ) reacting pyron with hydroxylamine or a hydroxylammonium compound in a solvent S1 ; and

2) crystallizing or precipitating piroctone from a solvent S2, with the proviso that, if solvent S2 used in step 2) is heptane, solvent S1 used in step 1 ) is not heptane.

Preferably, the solvent S1 in step 1 ) is selected from heptane, hexane, cyclohexane, methylcyclohexane, dimethylcyclohexane, toluene, benzene, methylene chloride, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tertbutanol, tert-amyl alcohol, dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, acetonitrile, 2-aminopyridine, methyl tert-butyl ether, dibutyl ether, diisopropyl ether, water, and mixtures thereof.

More preferably, the solvent S1 in step 1 ) is selected from heptane, hexane, cyclohexane, methylcyclohexane, toluene, 2-aminopyridine, and mixtures thereof.

Even more preferably, the solvent S1 in step 1 ) is selected from heptane, toluene, and mixtures thereof. Particularly preferably, the solvent S1 in step 1 ) is heptane. Also particularly preferably, the solvent S1 in step 1 ) is toluene. Preferably, the solvent S2 in step 2) is selected from heptane, hexane, cyclohexane, methylcyclohexane, dimethylcyclohexane, toluene, benzene, methylene chloride, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tertbutanol, tert-amyl alcohol, dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, acetonitrile, 2-aminopyridine, methyl tert-butyl ether, dibutyl ether, diisopropyl ether, water, and mixtures thereof.

More preferably, the solvent S2 in step 2) is selected from heptane, hexane, cyclohexane, methylcyclohexane, dimethylcyclohexane, methanol, ethanol, n- propanol, isopropanol, n-butanol, isobutanol, sec-butanol, methyl tert-butyl ether, dibutyl ether, diisopropyl ether, water, and mixtures thereof.

Even more preferably, the solvent S2 in step 2) is selected from heptane, hexane, cyclohexane, isopropanol, diisopropyl ether, water, and mixtures thereof. Even more preferably, the solvent S2 in step 2) is selected from heptane, hexane, cyclohexane, diisopropyl ether, and a mixture of isopropanol and water. Particularly preferably, the solvent S2 in step 2) is selected from heptane.

In a preferred embodiment, the solvent S2 in step 2) is a mixture of an alcohol and water. Preferably, the alcohol is selected from methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, tert-amyl alcohol, and mixtures thereof. In a particularly preferred embodiment, the solvent S2 in step 2) is a mixture of isopropanol and water. Preferably, the solvent S2 comprises at least 30 wt.-% of the alcohol (preferably isopropanol) and up to 70 wt.-% of water, based on the total weight of the solvent S2. More preferably, the solvent S2 comprises from 40 to 70 wt.-% of the alcohol (preferably isopropanol) and from 30 to 60 wt.-% of water, based on the total weight of the solvent S2. Particularly preferably, the solvent S2 comprises from 50 to 60 wt.-% of the alcohol (preferably isopropanol) and from 40 to 50 wt.-% of water, based on the total weight of the solvent S2.

In preferred embodiments, the solvent S1 in step 1) is heptane; and the solvent S2 in step 2) is selected from hexane, cyclohexane, isopropanol, diisopropyl ether, water, and mixtures thereof. In preferred embodiments, the solvent S1 in step 1 ) is heptane; and the solvent S2 in step 2) is selected from hexane, cyclohexane, diisopropyl ether, and a mixture of isopropanol and water.

In preferred embodiments, the solvent S1 in step 1 ) is toluene; and the solvent S2 in step 2) is selected from heptane, hexane, cyclohexane, isopropanol, diisopropyl ether, water, and mixtures thereof.

In preferred embodiments, the solvent S1 in step 1 ) is toluene; and the solvent S2 in step 2) is selected from heptane, hexane, cyclohexane, diisopropyl ether, and a mixture of isopropanol and water.

In particularly preferred embodiments, the solvent S1 in step 1 ) is toluene; and the solvent S2 in step 2) is heptane.

Pyron is reacted with hydroxylamine or a hydroxylammonium compound. In one embodiment, pyron is reacted with hydroxylamine. In a preferred embodiment, pyron is reacted with a hydroxylammonium compound. Preferred hydroxylammonium compounds are described further above. Preferred molar ratios of pyron to hydroxylamine equivalents are described further above.

In preferred embodiments, pyron is reacted with hydroxylamine or the hydroxylammonium compound in the presence of a base. In one embodiment, pyron is reacted with hydroxylamine in the presence of a base. In another embodiment, pyron is reacted with hydroxylamine in the absence of a base. In a preferred embodiment, pyron is reacted with the hydroxylammonium compound in the presence of a base. Preferred bases are described further above. Preferred molar ratios of hydroxylamine equivalents to base equivalents are described further above.

Preferably, pyron is reacted with hydroxylamine or the hydroxylammonium compound at a temperature of 50 to 120 °C, more preferably 60 to 100 °C, even more preferably 70 to 90 °C, particularly preferably 80 to 90 °C. Preferably, pyron is reacted with hydroxylamine or the hydroxylammonium compound for at least 4 hours, more preferably at least 8 hours, even more preferably at least 12 hours, particularly preferably at least 15 hours. For example, pyron is reacted with hydroxylamine or the hydroxylammonium compound for 8 to 24 hours, preferably 12 to 20 hours, particularly preferably 15 to 18 hours.

Preferably, piroctone is crystallized or precipitated at a temperature of -5 to 25 °C, more preferably 0 to 25 °C, even more preferably 0 to 20 °C, particularly preferably 0 to 5 °C, also particularly preferably 15 to 20 °C.

Preferably, piroctone is crystallized or precipitated from a solution of piroctone in the solvent S2, wherein the solvent S2 has a temperature of 50 to 85 °C, preferably 60 to 80 °C, particularly preferably 70 to 75 °C. Preferably, the solution of piroctone is cooled to a temperature of -5 to 25 °C, more preferably 0 to 25 °C, even more preferably 0 to 20 °C, particularly preferably 0 to 5 °C, also particularly preferably 15 to 20 °C.

The crystallized or precipitated piroctone obtained by the process of the present invention or the piroctone particles of the present invention can be dissolved in cosmetic compositions such as shampoos. In line with this, the crystallized or precipitated piroctone obtained by the process of the present invention or the piroctone particles of the present invention are suitable for use in cosmetic compositions such as shampoos.

The present invention also relates to the use of crystallized or precipitated piroctone obtained by the process of the present invention or piroctone particles of the present invention for the manufacture of a cosmetic composition.

In preferred embodiments, from 0.01 to 10 wt.-%, preferably from 0.05 to 5 wt.-%, more preferably from 0.1 to 2.0 wt.-%, even more preferably from 0.1 to 1.0 wt.-%, particularly preferably from 0.1 to 0.5 wt.-% of the piroctone, based on the total weight of the cosmetic composition, are used to manufacture the cosmetic composition.

For example, the cosmetic composition may be selected from the group consisting of shampoo, hair conditioner, hair tonic, cream rinse, body wash, bubble bath, bath oil, facial cleanser, cleansing mask, cleansing milk, micellar water, make-up remover, cleansing wipes, perfume, soaps, shaving soaps, shaving foams, cleansing foams, face mask, face cream, hand cream and body lotion.

Preferably, the cosmetic composition is a hair care composition, scalp care composition or skin care composition. More preferably, the cosmetic composition is a hair care or scalp care composition, particularly preferably a hair care and scalp care composition. Also more preferably, the cosmetic composition is a skin care composition.

Preferably, the cosmetic composition is a shampoo composition or hair conditioner composition. More preferably, the cosmetic composition is a shampoo composition, particularly preferably an anti-dandruff shampoo composition. Also more preferably, the cosmetic composition is a hair conditioner composition.

The cosmetic composition preferably comprises one or more further components (F). Preferred further components (F) and preferred amounts of such components are described further below. The further components (F) and amounts thereof described in this document for use in the cosmetic composition of the invention can also be used in the cosmetic composition manufactured according to the invention.

The cosmetic composition can be manufactured by methods known in the art. For example, the cosmetic composition can be manufactured by mixing its ingredients. For example, the piroctone can be mixed with the other ingredients of the cosmetic composition. The present invention also relates to a cosmetic composition comprising crystallized or precipitated piroctone obtained by the process of the present invention or piroctone particles of the present invention.

In preferred embodiments, the cosmetic composition of the invention comprises from 0.01 to 10 wt.-%, preferably from 0.05 to 5 wt.-%, more preferably from 0.1 to 2.0 wt.- %, even more preferably from 0.1 to 1 .0 wt.-%, particularly preferably from 0.1 to 0.5 wt.-% of the piroctone, based on the total weight of the cosmetic composition.

For example, the cosmetic composition of the invention may be selected from the group consisting of shampoo, hair conditioner, hair tonic, cream rinse, body wash, bubble bath, bath oil, facial cleanser, cleansing mask, cleansing milk, micellar water, make-up remover, cleansing wipes, perfume, soaps, shaving soaps, shaving foams, cleansing foams, face mask, face cream, hand cream and body lotion.

Preferably, the cosmetic composition of the invention is a hair care composition, scalp care composition or skin care composition. More preferably, the cosmetic composition of the invention is a hair care or scalp care composition, particularly preferably a hair care and scalp care composition. Also more preferably, the cosmetic composition of the invention is a skin care composition.

Preferably, the cosmetic composition of the invention is a shampoo composition or hair conditioner composition. More preferably, the cosmetic composition of the invention is a shampoo composition, particularly preferably an anti-dandruff shampoo composition. Also more preferably, the cosmetic composition of the invention is a hair conditioner composition.

In preferred embodiments, the cosmetic composition of the invention is a shampoo composition. The shampoo composition can be in the form of rinse-off products or ‘dry shampoo’ products, can be opaque or transparent, and can be formulated in a wide variety of product forms, including creams, gels, emulsions, mousses and sprays. Preferably, the shampoo composition is in the form of a rinse-off product. The shampoo composition can, for example, be used on human hair and/or scalp or animal hair, preferably human hair and/or scalp.

In preferred embodiments, the cosmetic composition of the invention is a hair conditioner composition. The hair conditioner composition can be in the form of rinse- off products or leave-on products, can be opaque or transparent, and can be formulated in a wide variety of product forms, including creams, gels, emulsions, mousses and sprays. Preferably, the hair conditioner composition is in the form of a rinse-off product.

In at least one embodiment, the cosmetic composition is in liquid form. In an alternative embodiment, the cosmetic composition is in solid form. Optionally, the cosmetic composition is in powdered or granulated form. This is advantageous in that it is not needed to ship liquid, which is typically heavy, over long distances, which has economic and environmental benefits. A solid form can be achieved by spray drying the composition or by using a rotary evaporator. A solid form can also be achieved by extrusion or pressing. The composition can be converted into liquid form after it has been shipped, e.g. by adding water.

The cosmetic composition of the invention preferably comprises one or more further components (F), which can be in an amount of at least 0.01% by weight, preferably at least 0.05% by weight, more preferably at least 0.1 % by weight, even more preferably at least 0.5% by weight of the cosmetic composition.

Preferably, the component (F) is selected from the group consisting of acidity regulators, colorants, conditioning agents, emulsifiers, film formers, fragrances, glossers, humectants, lubricants, moisturizers, pigments, preservatives, skin penetration enhancers, stabilizers, surfactants, thickeners, and viscosity modifiers. More preferably, the component (F) is selected from the group consisting of acidity regulators, glossers, lubricants, and surfactants.

Suitable lubricants are, for example, fatty alcohol components having 6 to 18 carbon atoms. The surfactants may, for example, be selected from non-polymeric, cationic quaternary ammonium compounds, in particular cetrimonium chloride (CTAC).

Suitable classical cationic conditioning agents include cationic quaternary ammonium salts. In at least one embodiment, the component (F) is a cationic quaternary ammonium salt. Examples of such quaternary ammonium salts include benzyl triethyl ammonium chloride, cetyl trimethylammonium chloride (cetrimonium chloride, CTAC), behentrimonium chloride (BTAC) or cetylpyridinium chloride.

As cationic components, a variety of cationic polymers are suitable, including quaternized cellulose ethers, copolymers of vinylpyrrolidone, acrylic polymers, including homopolymers or copolymers of dimethyldiallylammonium chloride or acrylamide. Also suitable are various types of homo- or copolymers derived from acrylic or methacrylic acid, acrylamide, methylacrylamide, diacetone-acrylamide.

In at least one embodiment, the component (F) is a glosser. Typical glossers are silicones. Suitable as silicones are volatile or nonvolatile non-ionic silicone fluids, silicone resins, and silicone semisolids or solids. Volatile silicones are linear or cyclic silicones having a measureable vapor pressure, which is defined as a vapor pressure of at least 2 mm of mercury at 20°C. Also suitable are water insoluble nonvolatile silicone fluids including polyalkyl siloxanes, polyaryl siloxanes, polyalkylaryl siloxanes, polyether siloxane copolymers, amine-functional silicones, or mixtures thereof.

The cosmetic composition of the invention may contain from 0.05 to 5%, preferably 0.5 to 5% by weight of at least one oil component. Typical oils are organic oils, which often are esters. The oil component may comprise glyceryl esters of fatty acids, or triglycerides, coconut oil, almond oil, apricot kernel oil, avocado oil, babassu oil, evening primrose oil, camelina sativa seed oil, grape seed oil, macadamia ternifolia seed oil, com oil, meadowfoam seed oil, mink oil, olive oil, palm kernel oil, safflower oil, sesame oil, soybean oil, sunflower oil, wheat germ oil, and camellia reticulata seed oil. The cosmetic composition of the invention may contain from 0.05 to 5%, preferably 0.5 to 5% by weight of at least one emulsifier. Preferred emulsifiers are, for example, sorbitan esters.

The cosmetic composition of the invention can contain from 0.1 to 10% by weight, preferably from 0.2 to 5% by weight, more preferably from 0.2 to 3% by weight, also more preferably from 0.5 to 5% by weight of at least one rheology modifying agent, in particular a gelling and thickening agent. Examples are cellulosic thickeners, for example, hydroxyethylcellulose, hydroxypropylcellulose, and carboxymethylcellulose, guar gum, such as hydroxypropylguar, gums of microbial origin, such as xanthan gum and scleroglucan gum, and synthetic thickeners, such as crosslinked homo- or copolymers of acrylic acid and/or of acrylamidopropanesulphonic acid. Other rheology modifying agents include fatty acid amides such as coconut diethanolamide and monoethanolamide, and oxyethylenated monoethanolamide of carboxylic acid alkyl ether.

Rheology modifying agents are also known as structuring materials. Common structuring materials include polymeric materials known as "carbomers", including, for example the cross-linked polyacrylic acid polymers available from Lubrizol Corporation under the trademark Carbopol®. Another class of (meth)acylic acid polymers are alkali-swellable emulsion (ASE) polymers. ASE polymers include, for example, Aculyn® 38 copolymer from Dow. Carbomers and ASE polymers belong to a class of materials known as hydrodynamic thickeners. These hydrodynamic thickeners include acid groups in their polymeric structure that, when deprotonated, form anionic charges that repel each other, causing the polymer chains to expand and entangle. Expansion and chain entanglement can give rise to thickening and suspending effects provided by the deprotonated polymers. The properties of these hydrodynamic thickeners are impacted by their molecular weight, acid group content, degree of cross-linking, and extent of swelling. These thickeners are also known as "space filling" or "volume excluding", and tend to increase both viscosity and yield point as the concentration thereof is increased. In use, hydrodynamic polymers commonly give rise to compositions that exhibit shear thinning or non-Newtonian behavior. Another class of (meth)acrylic acid based rheology modifiers are hydrophobically modified alkali swellable (HASE) polymers. Like ASE polymers, the HASE polymers include acid groups, the deprotonation of which gives rise to polymer swelling. Additionally, the HASE polymers include hydrophobic side groups, chains or blocks that give rise to associative interactions with each other, as well as with other hydrophobic species present in the compositions in which they are employed, for example, hydrophobic groups of surfactants, fatty acids, other thickening agents, and the like. Association creates hydrophobic regions distributed throughout the polymer chain network. This can also help to enhance the properties of the materials as solubilizing agents. Aculyn® 22 and Aculyn® 28 copolymers from Dow and Aqua SF 1® copolymer from Lubrizol Corporation are among the commonly used HASE materials. U.S. Patent 4,529,773 (Witiak et al.) reports alkali-soluble emulsion polymers activated by neutralization to a pH above 6.5, and subsequently acidified in the presence of a surfactant. These are described as useful thickeners in acidic compositions. The polymers are formed from the copolymerization of a monomer system that includes: (1 ) methacrylic or acrylic acid, (2) methacrylic or acrylic acid ester of a C8-C30 alkyl or, as therein more particularly described, a hydrocarbyl monoether of polyethylene glycol, (3) a C1-C4 alkyl acrylate or methacrylate, and, optionally, (4) a small amount of a polyethylenically unsaturated monomer.

The cosmetic composition of the invention can also comprise as component (F) a fatty compound. The fatty compound may be included in the cosmetic composition at a level of from 0.1 to 20 % by weight, preferably from 1 .0 to 10 % by weight. The fatty compound is selected from the group consisting of fatty alcohols (e.g. cetyl alcohol, stearyl alcohol or cetearyl alcohol), fatty acids, fatty alcohol derivatives, fatty acid derivatives, or mixtures thereof.

It is understood that the components disclosed can in some instances fall into more than one classification, e.g., some fatty alcohol derivatives can also be classified as fatty acid derivatives. However, a given classification, is not intended to be a limitation on that particular compound but is done so for convenience of classification and nomenclature. Non-limiting examples are found in International Cosmetic Ingredient Dictionary and Handbook, Fourteenth Edition (2014), and CTFA Cosmetic Ingredient Handbook, Second Edition, 1992. Preferably, fatty alcohols have 14 to 30 or 16 to 22 carbon atoms. These fatty alcohols are saturated and can be linear or branched. Examples of fatty alcohols are cetyl alcohol, stearyl alcohol, behenyl alcohol, and mixtures thereof. Preferred fatty acids have from 10 to 30 or from 12 to 22 carbon atoms. These fatty acids can be saturated and can be linear or branched. Also included herein are salts of these fatty acids. Examples of fatty acids are lauric acid, palmitic acid, stearic acid, behenic acid, sebacic acid, or mixtures thereof.

The fatty alcohol derivatives and fatty acid derivatives useful herein include alkyl ethers of fatty alcohols, alkoxylated fatty alcohols, alkyl ethers of alkoxylated fatty alcohols, esters of fatty alcohols, fatty acid esters of compounds having esterifiable hydroxy groups, hydroxy-substituted fatty acids, or mixtures thereof. Examples of fatty alcohol derivatives and fatty acid derivatives include methyl stearyl ether, polyoxyethylene ethers of behenyl alcohol, ethyl stearate, cetyl stearate, cetyl palmitate, stearyl stearate, myristyl myristate, polyoxyethylene cetyl ether stearate, polyoxyethylene stearyl ether stearate, polyoxyethylene lauryl ether stearate, ethyleneglycol monostearate, polyoxyethylene monostearate, polyoxyethylene distearate, propyleneglycol monostearate, propyleneglycol distearate, trimethylolpropane distearate, sorbitan stearate, polyglyceryl stearate, glyceryl monostearate, glyceryl distearate, glyceryl tristearate, or mixtures thereof.

The cosmetic composition of the invention may comprise an aqueous carrier. The level and species of the aqueous carrier are selected according to the compatibility with other components and other desired characteristic of the cosmetic composition. The aqueous carrier may, for example, be water or water solutions of lower alkyl alcohols or polyhydric alcohols. The lower alkyl alcohols may, for example, be monohydric alcohols having 1 to 6 carbons, often ethanol and/or isopropanol. The polyhydric alcohols may, for example, be propylene glycol, hexylene glycol, glycerin, and/or propane diol. Preferably, the aqueous carrier is substantially water. Deionized water is preferably used. Water from natural sources, including minerals can also be used, depending on the desired characteristic of the composition. Generally, the cosmetic composition of the invention can comprise up to 80 %, often even up to 95 % by weight of water. The cosmetic composition of the invention may also include as a further component (F) other components being suitable for rendering the compositions more cosmetically or aesthetically acceptable or to provide them with additional usage benefits. Such other components can generally be used individually at levels of from 0.001 % to 5 % by weight. A wide variety of further components (F) can be formulated into the cosmetic composition of the invention. These include conditioning agents, such as panthenol, panthenyl ethyl ether, proteins, hydrolysed proteins (preferably of vegetable or animal origin, for example hydrolysed collagen or hydrolysed keratin), nutrients; antioxidants, such as vitamin E; emollients, such as PPG-3 myristyl ether, trimethyl pentanol hydroxyethyl ether; hair-fixative polymers, such as amphoteric fixative polymers, cationic fixative polymers, anionic fixative polymers, non-ionic fixative polymers, silicone grafted copolymers; preservatives, such as benzyl alcohol, methyl paraben, propyl paraben, imidazolidinyl urea; pH adjusting agents, such as citric acid, sodium citrate, succinic acid, phosphoric acid, sodium hydroxide, sodium carbonate; salts, in general, such as potassium acetate or sodium chloride; coloring agents; hair oxidizing (bleaching) agents, such as hydrogen peroxide, perborate or persulfate salts; hair reducing agents such as thioglycolates; perfumes; and sequestering agents, such as disodium ethylene-diamine tetraacetate.

Preferably, salt is present at levels from 0.1 to 1 wt.-% of the total cosmetic composition to adjust the product viscosity. Preferably, NaOH is present at levels from 0.1 to 1 wt.-% of the total cosmetic composition to adjust the pH of the formulation.

The cosmetic composition of the invention may contain as a further component (F) a polysorbate for adjusting rheology, for example, polysorbate-20, polysorbate-21 , polysorbate-40, polysorbate-60, or mixtures thereof. The polysorbate can be contained in the cosmetic composition in amounts up to 5% (e.g. 0.1 to 5%) by weight.

The cosmetic composition of the invention can also contain as a further component

(F) a polypropylene glycol. Preferred polypropylene glycols are those having a weight average molecular weight of from 200 to 100000 g/mol. The polypropylene glycol may be either water-soluble, water-insoluble, or may have a limited solubility in water, depending upon the degree of polymerization and whether other moieties are attached thereto. The desired solubility of the polypropylene glycol in water will depend in large part upon the form of the composition (e.g., leave-on composition, rinse-off composition). The polypropylene glycol can be included in the cosmetic composition of the invention at a level of up to 10% by weight.

For example, in a rinse-off composition, it is preferred that the polypropylene glycol has a solubility in water at 25°C of less than about 1 g/100 g water, more preferably a solubility in water of less than about 0.5 g/100 g water, and even more preferably a solubility in water of less than about 0.1 g/100 g water. The polypropylene glycol can be included in the cosmetic composition of the invention at a level of up to 10% by weight.

The cosmetic composition of the invention can also contain, as a further component (F), low melting point oil selected from the group consisting of hydrocarbons having from 10 to 40 carbon atoms; unsaturated fatty alcohols having from 10 to 30 carbon atoms such as oleyl alcohol; unsaturated fatty acids having from about 10 to about 30 carbon atoms; fatty acid derivatives; fatty alcohol derivatives; ester oils such as pentaerythritol ester oils, trimethylol ester oils, citrate ester oils, or glyceryl ester oils; poly [alpha]-olefin oils; and mixtures thereof. Preferred low melting point oils are selected from the group consisting of ester oils such as pentaerythritol ester oils, trimethylol ester oils, citrate ester oils, or glyceryl ester oils; poly [alpha]-olefin oils; and mixtures thereof. Particularly useful pentaerythritol ester oils and trimethy lol ester oils are pentaerythritol tetraisostearate, pentaerythritol tetraoleate, trimethylolpropane triisostearate, trimethylolpropane trioleate, or mixtures thereof. Particularly useful glyceryl esters are triisostearin, triolein or tril inolein.

The cosmetic composition of the invention can also contain, as a further component (F), a cationic polymer. Cationic polymers may be present in the cosmetic composition of the invention for further enhancing deposition performance. Suitable cationic polymers may be homopolymers which are cationically substituted or may be formed from two or more types of monomers. The weight average (Mw) molecular weight of the polymers will generally be between 100 000 and 2 million g/mol. The polymers will have cationic nitrogen containing groups such as quaternary ammonium or protonated amino groups, or a mixture thereof. If the molecular weight of the polymer is too low, then the conditioning effect is poor. If too high, then there may be problems of high extensional viscosity leading to stringiness of the composition when it is poured.

The cationic nitrogen-containing group will generally be present as a substituent on a fraction of the total monomer units of the cationic polymer. Thus, when the polymer is not a homopolymer it can contain non-cationic spacer monomer units. Such polymers are described in the CTFA Cosmetic Ingredient Directory, 3rd edition. The ratio of the cationic to non-cationic monomer units is selected to give polymers having a cationic charge density in the required range, which is generally from 0.2 to 3.0 meq/gm. The cationic charge density of the polymer is suitably determined via the Kjeldahl method as described in the US Pharmacopoeia under chemical tests for nitrogen determination.

Suitable cationic polymers include, for example, copolymers of vinyl monomers having cationic amine or quaternary ammonium functionalities with water soluble spacer monomers such as (meth)acrylamide, alkyl and dialkyl (meth)acrylamides, alkyl (meth)acrylate, vinyl caprolactone and vinyl pyrrolidine. The alkyl and dialkyl substituted monomers preferably have C1-C7 alkyl groups, more preferably C1-3 alkyl groups. Other suitable spacers include vinyl esters, vinyl alcohol, maleic anhydride, propylene glycol and ethylene glycol. The cationic amines can be primary, secondary or tertiary amines, depending upon the particular species and the pH of the composition. In general, secondary and tertiary amines, especially tertiary, are preferred. Amine substituted vinyl monomers and amines can be polymerized in the amine form and then converted to ammonium by quaternization. The cationic polymers can comprise mixtures of monomer units derived from amine- and/or quaternary ammonium-substituted monomer and/or compatible spacer monomers. Suitable cationic polymers include, for example cationic diallyl quaternary ammonium-containing polymers including, for example, dimethyldiallylammonium chloride homopolymer and copolymers of acrylamide and dimethyldiallylammonium chloride, referred to in the industry (CTFA) as Polyquaternium 6 and Polyquaternium 7, respectively; mineral acid salts of amino-alkyl esters of homo- and co-polymers of unsaturated carboxylic acids having from 3 to 5 carbon atoms, (as described in US4009256A1 from NAT STARCH CH EM CORP); cationic polyacrylamides (as described in WO95/22311A1 Unilever PLC).

Other cationic polymers that can be used include cationic polysaccharide polymers, such as cationic cellulose derivatives, cationic starch derivatives, and cationic guar gum derivatives.

Cationic polysaccharide polymers suitable for use in the cosmetic composition of the invention include monomers of the formula: A-O-[R-N⁺(R1 )(R2)(R3)X^_], wherein: A is an anhydroglucose residual group, such as a starch or cellulose anhydroglucose residual. R is an alkylene, oxyalkylene, polyoxyalkylene, or hydroxyalkylene group, or combination thereof. R1 , R2 and R3 independently represent alkyl, aryl, alkylaryl, arylalkyl, alkoxyalkyl, or alkoxyaryl groups, each group containing up to about 18 carbon atoms. The total number of carbon atoms for each cationic moiety (i.e. , the sum of carbon atoms in R1 , R2 and R3) is preferably about 20 or less, and X’ is an anionic counterion. Another type of cationic cellulose includes the polymeric quaternary ammonium salts of hydroxyethyl cellulose reacted with lauryl dimethyl ammonium-substituted epoxide, referred to in the industry (CTFA) as Polyquaternium 24. These materials are available from the Amerchol Corporation, for instance under the trade name Polymer LM-200. Other suitable cationic polysaccharide polymers include quaternary nitrogen-containing cellulose ethers (e.g. as described in US3962418 from L’Oreal), and copolymers of etherified cellulose and starch (e.g. as described in US3958581 from L’Oreal).

A particularly suitable type of cationic polysaccharide polymer that can be used is a cationic guar gum derivative, such as guar hydroxypropyltrimethylammonium chloride (commercially available from Solvay in their JAGUAR trade named series). Examples of such materials are JAGUAR C13S, JAGUAR C14, JAGUAR C15, JAGUAR C17, JAGUAR C16, JAGUAR CHT and JAGUAR C162.

Mixtures of any of the above cationic polymers may be used. Cationic polymer may be present in the cosmetic composition of the invention at levels of from 0.01 to 5 wt.- %, preferably from 0.05 to 1 wt.-%, more preferably from 0.08 to 0.5 wt.-% by total weight of cationic polymer based on the total weight of the cosmetic composition.

In at least one embodiment, the cationic polymers have a number average molecular weight of at least about 5000 g/mol, typically from 10000 g/mol to 10 million g/mol and are selected from the group consisting of copolymers of vinyl monomers having cationic amine or quaternary ammonium functionalities with water soluble spacer monomers such as acrylamide, methacrylamide, alkyl and dialkyl acrylamides, alkyl and dialkyl methacrylamides, alkyl acrylate, alkyl methacrylate, vinyl caprolactone, and vinyl pyrrolidone. Other suitable spacer monomers include vinyl esters, vinyl alcohol, maleic anhydride, propylene glycol, and ethylene glycol. Preferred cationic polymers are cationic celluloses, cationic starches, and cationic guar gums. Commercially available cationic guar polymers are e.g. Jaguar® from Solvay.

In at least one embodiment, the cosmetic composition of the invention comprises a surfactant system. In at least one embodiment, the surfactant system comprises a surfactant selected from the group consisting of anionic surfactants, cationic surfactants, non-ionic surfactants, zwitterionic surfactants and/or amphoteric surfactants. In at least one embodiment, the cosmetic composition of the invention comprises a total amount of surfactant of from 0.01 wt.-% to 70 wt.-%, from 0.1 wt.-% to 40%, from 1 wt.-% to 30%, from 2 wt.-% to 20 wt.-%.

In at least one embodiment, the cosmetic composition of the invention comprises an anionic surfactant. In at least one embodiment, the anionic surfactant is selected from the group consisting of (C10-C20)-alkyl and alkylene carboxylates, alkyl ether carboxylates, fatty alcohol sulfates, fatty alcohol ether sulfates, alkylamide sulfates and sulfonates, fatty acid alkylamide polyglycol ether sulfates, alkanesulfonates and hydroxyalkanesulfonates, olefinsulfonates, acyl esters of isethionates, alpha-sulfo fatty acid esters, alkylbenzenesulfonates, alkylphenol glycol ether sulfonates, sulfosuccinates, sulfosuccinic monoesters and diesters, fatty alcohol ether phosphates, protein/fatty acid condensation products, alkyl monoglyceride sulfates and sulfonates, alkylglyceride ether sulfonates, fatty acid methyltaurides, fatty acid sarcosinates, sulforicinoleates, acylglutamates, and mixtures thereof. The anionic surfactants (and their mixtures) can be used in the form of their water-soluble or water-dispersible salts, examples being the sodium, potassium, magnesium, ammonium, mono-, di-, and triethanolammonium, and analogous alkylammonium salts. In at least one embodiment, the anionic surfactant is the salt of an anionic surfactant comprising 12 to 14 carbon atoms. In at least one embodiment, the anionic surfactant is selected from the group consisting of sodium lauryl sulfate, sodium laureth sulfate, sodium tridecyl sulfate, sodium trideceth sulfate, sodium myristyl sulfate, sodium myreth sulfate, and mixtures thereof. Typical anionic surfactants for use in the cosmetic composition of the invention include sodium oleyl succinate, ammonium lauryl sulphosuccinate, sodium lauryl sulphate, sodium lauryl ether sulphate, sodium lauryl ether sulphosuccinate, ammonium lauryl sulphate, ammonium lauryl ether sulphate, sodium dodecyl benzene sulphonate, triethanolamine dodecylbenzene sulphonate, sodium cocoyl isethionate, sodium lauryl isethionate, lauryl ether carboxylic acid and sodium N-lauryl sarcosinate. Preferred anionic surfactants are selected from sodium lauryl sulphate and sodium lauryl ether sulphate(n)EO, where n is from 1 to 3; more preferably sodium lauryl ether sulphate(n)EO, where n is from 1 to 3; most preferably sodium lauryl ether sulphate(n)EO, where n=1 . Preferably, the level of alkyl ether sulphate is from 0.5 wt.-% to 25 wt.-% of the total composition, more preferably from 3 wt.-% to 18 wt.-%, most preferably from 6 wt.-% to 15 wt.-% of the total composition.

The total amount of anionic surfactant in the cosmetic composition of the invention may range from 0.5 wt.-% to 45 wt.-%, more preferably from 1 .5 wt.-% to 20 wt.-%.

The cosmetic composition of the invention may comprise fatty acyl isethionate, if present, preferably at a level of from 1 to 10 wt.-%, more preferably from 2 to 8 wt.-%, most preferably from 2.5 to 7.5 wt.-%. A preferred fatty acyl isethionate product comprises fatty acyl isethionate surfactant at a level of from 40 to 80 wt.-% of the product, as well as free fatty acid and/or fatty acid salt at a level of from 15 to 50 wt.- %. Preferably, greater than 20 wt.-% and less than 45 wt.-%, more preferably greater than 25 wt.-% and less than 45 wt.-% of the fatty acyl isethionate are of chain length greater than or equal to C16; and greater than 50 wt.-%, preferably greater than 60 wt.-% of the free fatty acid/soap is of chain length C16 to C20. In addition, the product may contain isethionate salts, which are present typically at levels less than 5 wt.-%, and traces (less than 2 wt.-%) of other impurities.

Preferably, a mixture of aliphatic fatty acids is used for the preparation of commercial fatty acyl isethionate surfactants. The resulting fatty acyl isethionate surfactants (e.g., resulting from the reaction of alkali metal isethionate and aliphatic fatty acid) preferably should have more than 20 wt.-%, preferably more than 25 wt.-%, but no more than 45 wt.-%, preferably 35 wt.-% (on basis of fatty acyl isethionate reaction product) of fatty acyl group with 16 or greater carbon atoms to provide both excellent lather and mildness of the resulting fatty acyl isethionate product. These longer chain fatty acyl isethionate surfactants and fatty acids, i.e. fatty acyl group and fatty acid with 16 or more carbons, can typically form insoluble surfactant/fatty acid crystals in water at ambient temperatures.

In at least one embodiment, the cosmetic composition of the invention comprises an acylglycinate surfactant. In at least one embodiment, the acylglycinate surfactant conforms to the formula (Y): wherein

R^1a is a linear or branched, saturated alkyl group having 6 to 30, preferably 8 to 22, particularly preferably 8 to 18 carbon atoms or is a linear or branched, mono- or polyunsaturated alkenyl group having 6 to 30, preferably 8 to 22, particularly preferably 12 to 18 carbon atoms, and Q_a ⁺ is a cation. In at least one embodiment, Q_a ⁺ is selected from the group consisting of Li⁺, Na⁺, K⁺, Mg⁺⁺, Ca⁺⁺, Al⁺⁺⁺, NH4⁺, a monoalkylammmonium ion, a dialkylammonium ion, a trialkylammonium ion and a tetraalkylammonium ion, or combinations thereof. In at least one embodiment, the acylglycinate surfactant is selected from sodium cocoylglycinate and potassium cocoylglycinate. In at least one embodiment, the acylglycinate surfactant is selected from those conforming to formula (Y), wherein R is C12 alkyl or C14 alkyl. In at least one embodiment, the acylglycinate surfactant is selected from those conforming to formula (Y), wherein R is C16 alkyl or C18 alkyl.

In at least one embodiment, the cosmetic composition comprises from 0.01 wt.-% to 30 wt.-%, or from 1 wt.-% to 25 wt.-%, preferably from 5 wt.-% to 20 wt.-%, more preferably from 12 wt.-% to 18 wt.-% anionic surfactant.

In at least one embodiment, the cosmetic composition of the invention comprises a glutamate surfactant corresponding to formula (Z) or a salt thereof: wherein R’ is HOOC-CH2-CH2- or M⁺ OOC-CH2-CH2- wherein M⁺ is a cation; and wherein R is a linear or branched, saturated alkyl group having 6 to 30, preferably 8 to 22, more preferably 8 to 18 carbon atoms or is a linear or branched, mono- or polyunsaturated alkenyl group having 6 to 30, preferably 8 to 22, more preferably 12 to 18 carbon atoms. In at least one embodiment, M⁺ is a metal cation. In at least one embodiment, M⁺ is selected from the group consisting of Li⁺, Na⁺, K⁺, Mg⁺⁺, Ca⁺⁺, Al⁺⁺⁺, NH₄ ⁺, a monoalkylammmonium ion, a dialkylammonium ion, a trialkylammonium ion and a tetraalkylammonium ion, or combinations thereof. In at least one embodiment, the glutamate surfactant is selected from sodium cocoyl glutamate and potassium cocoyl glutamate. In at least one embodiment, the glutamate surfactant is selected from those conforming to formula (Z), wherein R is C12 alkyl or C14 alkyl. In at least one embodiment, the glutamate surfactant is selected from those conforming to formula (Z), wherein R is C16 alkyl or C18 alkyl. In at least one embodiment, the cosmetic composition of the invention comprises a non-ionic surfactant. Non-ionic surfactants may be present in the range 0 to 5 wt.-%. Non-ionic surfactants that can be included in the cosmetic composition of the invention include condensation products of aliphatic primary or secondary linear or branched chain alcohols or phenols with alkylene oxides, usually ethylene oxide and generally having from 6 to 30 ethylene oxide groups. Alkyl ethoxylates are particularly preferred. Most preferred are alky ethoxylates having the formula

R-(OCH₂CH₂)_nOH, where R is an alkyl chain of C12 to C15, and n is 5 to 9. Other suitable non-ionic surfactants include mono- or di-alkyl alkanolamides. Examples include coco mono- or di-ethanolamide and coco mono-isopropanolamide.

Further non-ionic surfactants which can be included in the cosmetic composition of the invention are alkyl polyglycosides (APGs). Typically, APG is one which comprises an alkyl group connected (optionally via a bridging group) to a block of one or more glycosyl groups. Preferred APGs are defined by the following formula:

RO-(G)_n wherein R is a branched or straight chain alkyl group which may be saturated or unsaturated, and G is a saccharide group. R may represent a mean alkyl chain length of from about C5 to about C20. Preferably R represents a mean alkyl chain length of from about C9 to about C12. G may be selected from C5 or C6 monosaccharide residues, and is preferably a glucoside. G may be selected from the group comprising glucose, xylose, lactose, fructose, mannose and derivatives thereof. Preferably G is glucose. The degree of polymerisation, n, may have a value of from about 1 to about 10 or more. Most preferably the value of n lies between about 1 .3 to about 1 .5. Suitable alkyl polyglycosides for use in the invention are commercially available and include for example those materials identified as: Oramix NS10 ex Seppic; Plantaren 1200 and Plantaren 2000 ex Henkel.

Other sugar-derived non-ionic surfactants which can be included in the cosmetic composition of the invention include fatty (e.g. C10-C18) N-alkyl (C1-C6) polyhydroxy fatty acid amides, such as C12-C18 N-methyl glucamides, as described for example in WO9206154 and LIS5194639, and N-alkoxy polyhydroxy fatty acid amides. In at least one embodiment, the non-ionic surfactant has an HLB (Hydrophilic Lipophilic Balance) of greater than 12. Optionally, the non-ionic surfactant is selected from the group consisting of ethoxylated or ethoxylated/propoxylated fatty alcohols with a fatty chain comprising from 12 to 22 carbon atoms, ethoxylated sterols, such as stearyl- or lauryl alcohol (EO-7), PEG-16 soya sterol or PEG-10 soya sterol, polyoxyethylene polyoxypropylene block polymers (poloxamers), and mixtures thereof.

In at least one embodiment, the non-ionic surfactant is selected from the group consisting of ethoxylated fatty alcohols, fatty acids, fatty acid glycerides or alkylphenols, in particular addition products of 2 to 30 mol of ethylene oxide and/or 1 to 5 mol of propylene oxide onto C8- to C22-fatty alcohols, onto C12- to C22-fatty acids or onto alkyl phenols having 8 to 15 carbon atoms in the alkyl group, C12- to C22-fatty acid mono- and diesters of addition products of 1 to 30 mol of ethylene oxide onto glycerol, addition products of 5 to 60 mol of ethylene oxide onto castor oil or onto hydrogenated castor oil, fatty acid sugar esters, in particular esters of sucrose and one or two C8- to C22-fatty acids, INCI: Sucrose Cocoate, Sucrose Dilaurate, Sucrose Distearate, Sucrose Laurate, Sucrose Myristate, Sucrose Oleate, Sucrose Palmitate, Sucrose Ricinoleate, Sucrose Stearate, esters of sorbitan and one, two or three C8- to C22-fatty acids and a degree of ethoxylation of from 4 to 20, polyglyceryl fatty acid esters, in particular of one, two or more C8- to C22-fatty acids and polyglycerol having preferably 2 to 20 glyceryl units, alkyl glucosides, alkyl oligoglucosides and alkyl polyglucosides having C8 to C22-alkyl groups, e.g. decylglucoside or laurylglucoside, and mixtures thereof.

In at least one embodiment, the non-ionic surfactant is selected from the group consisting of fatty alcohol ethoxylates (alkylpolyethylene glycols), alkylphenol polyethylene glycols, alkylmercaptan polyethylene glycols, fatty amine ethoxylates (alkylaminopolyethylene glycols), fatty acid ethoxylates (acylpolyethylene glycols), polypropylene glycol ethoxylates (Pluronics®), fatty acid alkylol amides, (fatty acid amide polyethylene glycols), N-alkyl-, N -alkoxy poly-hydroxy-fatty acid amide, sucrose esters, sorbitol esters, polyglycol ethers, and mixtures thereof. In at least one embodiment, the cosmetic composition of the invention comprises a fatty N-methyl-N-glucamide surfactant. In at least one embodiment, the fatty N- methyl-N-glucamide surfactant conforms to the formula (X): wherein

R is a linear or branched alkyl or alkenyl group having from 3 to 30 carbon atoms. In at least one embodiment, R is an alkyl group having from 3 to 30 carbon atoms. In at least one embodiment, R is a saturated aliphatic hydrocarbon group which can be linear or branched and can have from 3 to 20 carbon atoms in the hydrocarbon chain, preferably linear or branched. Branched means that a lower alkyl group such as methyl, ethyl or propyl is present as substituent on a linear alkyl chain. In at least one embodiment, R is selected from the group consisting of 1 -propyl, 2-propyl, 1 butyl, 2-butyl, 2-methyl-1 -propyl (isobutyl), 2-methyl-2-propyl (tert-butyl), 1 -pentyl, 2- pentyl, 3-pentyl, 2-methyl-1 -butyl, 3-methyl-1 -butyl, 2 methyl-2-butyl, 3-methyl-2- butyl, 2, 2-dimethyl-1 -propyl, 1 -hexyl, 2-hexyl, 3-hexyl, 2-methyl-1 -pentyl, 3-methyl-1- pentyl, 4-methyl-1 -pentyl, 2-methyl-2-pentyl, 3 methyl-2-pentyl, 4-methyl-2-pentyl, 2 methyl-3-pentyl, 3-methyl-3-pentyl, 2,2 dimethyl-1 -butyl, 2,3-dimethyl-1 -butyl, 3,3 dimethyl-1 -butyl, 2-ethyl-1 -butyl, 2,3-dimethyl-2-butyl, 3,3-dimethyl-2-butyl, 1 heptyl, 1 -octyl, 1 -nonyl, 1 -decyl, 1 undecyl, 1 -dodecyl, 1 -tetradecyl, 1 -hexadecyl and 1- octadecyl. Suitable fatty N methyl-N-glucamide surfactants are described in WO201 3/178700 and EP 0 550637, which are incorporated herein by reference. In at least one embodiment, the N-methyl-N-glucamide surfactant is selected from those conforming to formula (X), wherein R is C12 alkyl or C14 alkyl. In at least one embodiment, the N-methyl-N-glucamide surfactant is selected from those conforming to formula (X), wherein R is C16 alkyl or C18 alkyl. In at least one embodiment, the cosmetic composition of the invention comprises from 1 wt.-% to 20 wt.-%, more preferably from 2 wt.-% to 10 wt.-%, even more preferably from 3 wt.-% to 7 wt.-% non-ionic surfactant.

Amphoteric or zwitterionic surfactant can be included in the cosmetic composition of the invention in an amount ranging from 0.5 wt.-% to about 8 wt.-%, preferably from 1 wt.-% to 4 wt.-% of the total composition.

In at least one embodiment, the amphoteric surfactants are selected from the group consisting of N-(Ci2-Ci8)-alkyl-beta-aminopropionates and N-(Ci2-Cis)-alkyl-beta- iminodipropionates as alkali metal salts and mono-, di-, and trialkylammonium salts; N-acylaminoalkyl-N,N-dimethylacetobetaine, preferably N-(C8-Ci8)-acylaminopropyl- N,N-dimethylacetobetaine; (Ci2-Ci8)-alkyl-dimethyl-sulfopropylbetaine; amphosurfactants based on imidazoline (trade name: Miranol®, Steinapon®), preferably the sodium salt of 1-(beta-carboxymethyloxyethyl)-1-(carboxymethyl)-2- laurylimidazolinium; amine oxide, e.g., (Ci2-Ci8)-alkyl-dimethylamine oxide, fatty acid amidoalkyldimethylamine oxide, and mixtures thereof.

In at least one embodiment, the cosmetic composition of the invention comprises a betaine surfactant. Optionally, the betaine surfactant is selected from C8- to C18- alkylbetaines. In at least one embodiment, the betaine surfactant is selected from the group consisting of cocodimethylcarboxymethylbetaine, lauryldimethylcarboxymethylbetaine, lauryldimethylalphacarboxyethylbetaine, cetyldimethylcarboxymethylbetaine, oleyldimethylgammacarboxypropylbetaine and laurylbis(2-hydroxypropyl)alphacarboxyethylbetaine and combinations thereof. Optionally, the betaine surfactant is selected from C8- to C18-sulfobetaines. In at least one embodiment, the betaine surfactant is selected from the group consisting of cocodimethylsulfopropylbetaine, stearyldimethylsulfopropylbetaine, lauryldimethylsulfoethylbetaine, laurylbis(2-hydroxyethyl)sulfopropylbetaine, and combinations thereof. Optionally, the betaine surfactant is selected from carboxyl derivatives of imidazole, the C8- to C18-alkyldimethylammonium acetates, the C8- to C18 alkyldimethylcarbonylmethylammonium salts, and the C8- to C18-fatty acid alkylamidobetaines, and mixtures thereof. Optionally, the C8- to C18-fatty acid alkylamidobetaine is selected from coconut fatty acid amidopropylbetaine, N-coconut fatty acid amidoethyl-N-[2-(carboxymethoxy)ethyl]glycerol (CTFA name: cocoamphocarboxyglycinate), and mixtures thereof. A particularly preferred amphoteric or zwitterionic surfactant is cocamidopropyl betaine. Mixtures of any of the foregoing amphoteric or zwitterionic surfactants may also be suitable. Preferred mixtures are those of cocamidopropyl betaine with further amphoteric or zwitterionic surfactants as described above. A preferred further amphoteric or zwitterionic surfactant is sodium cocoamphoacetate.

In at least one embodiment, the cosmetic composition of the invention comprises from 0.5 wt.-% to 20 wt.-%, preferably from 1 wt.-% to 10 wt.-% amphoteric surfactant.

In at least one embodiment, the cosmetic composition of the invention comprises a surfactant system. In at least one embodiment, the surfactant system comprises at least one surfactant selected from the group consisting of lauryl sulfate, laureth sulfate, cocamidopropyl betaine, sodium cocoylglutamate, lauroamphoacetate, and mixtures thereof. In at least one embodiment, the surfactant system comprises sodium laureth sulfate, sodium lauryl sulfate, and optionally cocamidopropyl betaine. In at least one embodiment, the surfactant system comprises sodium laureth sulfate, potassium cocoylglutamate, and cocamidopropyl betaine.

In at least one embodiment, the cosmetic composition of the invention contains as a further component a silicone compound. The cosmetic composition can comprise up to 5% (e.g. 0.1 to 5%) by weight of a silicone compound. Suitable silicone compounds include polyalkyl or polyaryl siloxanes. The preferred silicone compounds are polydimethylsiloxane, polydiethylsiloxane, and polymethylphenylsiloxane, e.g. available from Wacker (Germany) or Dow Corning, such as Xiameter PMX DC 200. Silicone compounds can be available as silicone oils or emulsions. The silicone compounds may further be incorporated in the present composition in the form of an emulsion, wherein the emulsion is pre-made and added to the formulation, or made during the formulation process by mechanical mixing with or without the aid of an additional surfactant selected from anionic surfactants, non-ionic surfactants, cationic surfactants, and mixtures thereof.

In at least one embodiment, the cosmetic composition of the invention contains silicone conditioning agents. Preferably, these are emulsified droplets of a silicone conditioning agent. These are for enhancing conditioning performance.

Suitable silicones include polydiorganosiloxanes, in particular polydimethylsiloxanes, which have the CTFA designation dimethicone. Also suitable for use in the cosmetic composition of the invention are polydimethyl siloxanes having hydroxyl end groups, which have the CTFA designation dimethiconol. Also suitable for use in the cosmetic composition of the invention are silicone gums having a slight degree of cross-linking, as are described for example in WO 96/31188. The viscosity of the emulsified silicone itself (not the emulsion or the final composition) is typically at least 10,000 cSt at 25°C. The viscosity of the silicone itself is preferably at least 60,000 cSt, most preferably at least 500,000 cSt, ideally at least 1 ,000,000 cSt. Preferably, the viscosity does not exceed 1x10⁹ cSt for ease of formulation. Emulsified silicones for use in the cosmetic composition of the invention will typically have an average silicone droplet size in the composition of less than 30, preferably less than 20, more preferably less than 10 micron, ideally from 0.01 to 1 micron. Silicone emulsions having an average silicone droplet size of less than 0.15 micron are generally termed microemulsions.

Silicone particle size may be measured by means of a laser light scattering technique, for example using a 2600D Particle Sizer from Malvern Instruments. Examples of suitable pre-formed emulsions include Xiameter MEM 1785 and microemulsion DC2-1865 available from Dow Coming. These are emulsions I microemulsions of dimethiconol. Cross-linked silicone gums are also available in a pre-emulsified form, which is advantageous for ease of formulation. A further preferred class of silicones for inclusion in the cosmetic composition of the invention are amino functional silicones. By "amino functional silicone" is meant a silicone containing at least one primary, secondary or tertiary amine group, or a quaternary ammonium group. Examples of suitable amino functional silicones include polysiloxanes having the CTFA designation "amodimethicone". Specific examples of amino functional silicones suitable for use in the cosmetic composition of the invention are the aminosilicone oils DC2-8220, DC2-8166 and DC2-8566 (all ex Dow Coming). Suitable quaternary silicone polymers are described in EP-A-0 530 974. A preferred quaternary silicone polymer is K3474, ex Goldschmidt.

Also suitable are emulsions of amino functional silicone oils with non-ionic and/or cationic surfactants. Pre-formed emulsions of amino functional silicones are also available from suppliers of silicone oils such as Dow Corning and General Electric. Specific examples include DC939 Cationic Emulsion and the non-ionic emulsions DC2-7224, DC2- 8467, DC2-8177 and DC2-8154 (all ex Dow Coming).

Combination of amino and non-amino functional silicones may also be used.

The total amount of silicone is preferably from 0.01 wt.-% to 10 wt.-% of the total composition, more preferably from 0.1 wt.-% to 5 wt.-%, most preferably from 0.5 wt.- % to 3 wt.-%.

In at least one embodiment, the cosmetic composition of the invention comprises a preservative or preservative system. Examples of suitable preservatives include benzyl alcohol, phenoxyethanol, parabens, benzoic acid/sodium benzoate, sorbic acid/potassium sorbate, and other organic acids used to provide antimicrobial protection. In at least one embodiment, the cosmetic composition comprises from 0.01 to 5 wt.-%, particularly preferably from 0.05 to 1 wt.-% of at least one preservative. Suitable preservatives are the substances listed in the International Cosmetic Ingredient Dictionary and Handbook, 9th Edition with the function "preservatives". In at least one embodiment, the preservative is selected from the group consisting of phenoxyethanol, benzyl paraben, butyl paraben, ethyl paraben, isobutyl paraben, isopropyl paraben, methyl paraben, propyl paraben, iodopropynyl butylcarbamate, methyldibromoglutaronitrile, DMDM hydantoin and combinations thereof. In at least one embodiment, the cosmetic composition comprises a preservative selected from the group consisting of cetyltrimethyl ammonium chloride, cetylpyridinium chloride, benzethonium chloride, diisobutylethoxyethyldimethyl benzylammonium chloride, sodium N-lauryl sarcosinate, sodium-N- palmethylsarcosinate, lauroylsarcosine, N-myristoylglycine, potassium-N- laurylsarcosine, trimethylammonium chloride, sodium aluminium chlorohydroxylactate, triethylcitrate, tricetylmethylammonium chloride, 2,4,4'-trichloro- 2'-hydroxydiphenylether (Triclosan), phenoxyethanol, 3,4,4'-trichlorocarbanilide (Triclocarban), diaminoalkylamide, L-lysine hexadecylamide, heavy metal citrate salts, zinc salts, zinc phenol sulfate, farnesol, naftifine, terbinafine, selenium disulfide, methylchloroisothiazolinone, methylisothiazolinone, methyldibromo glutaronitrile, AgCI, chloroxylenol, sodium salts of diethylhexylsulfosuccinate, sodiumbenzoate, phenoxyethanol, benzyl alcohol, phenoxyisopropanol, paraben, such as butyl-, ethyl-, methyl- und propylparaben, and their salts, sorbic acid, benzoic acid, lactic acid, imidazolidinyl urea, diazolidinyl urea, dimethylol dimethyl hydantoin (DMDMH), sodium salts of hydroxymethyl glycinate, hydroxyethylglycine of sorbic acid and combinations thereof. In at least one embodiment, the preservative is selected from the group consisting of phenoxyethanol, benzyl paraben, butyl paraben, ethyl paraben, isobutyl paraben, isopropyl paraben, methyl paraben, propyl paraben, iodopropynyl butylcarbamate, methyldibromoglutaronitrile, DMDM hydantoin and combinations thereof. In at least one embodiment, the cosmetic composition of the invention is substantially free of parabens.

The cosmetic composition of the invention may also comprise a dispersed, nonvolatile, water-insoluble oily conditioning agent. By "insoluble" is meant that the material is not soluble in water (distilled or equivalent) at a concentration of 0.1 % (w/w), at 25°C.

Suitable oily or fatty materials are selected from hydrocarbon oils, fatty esters and mixtures thereof. Straight chain hydrocarbon oils will preferably contain from about 12 to about 30 carbon atoms. Also suitable are polymeric hydrocarbons of alkenyl monomers, such as C2-C6 alkenyl monomers. Specific examples of suitable hydrocarbon oils include paraffin oil, mineral oil, saturated and unsaturated dodecane, saturated and unsaturated tridecane, saturated and unsaturated tetradecane, saturated and unsaturated pentadecane, saturated and unsaturated hexadecane, and mixtures thereof. Branched-chain isomers of these compounds, as well as of higher chain length hydrocarbons, can also be used.

Suitable fatty esters are characterised by having at least 10 carbon atoms, and include esters with hydrocarbyl chains derived from fatty acids or alcohols. Monocarboxylic acid esters include esters of alcohols and/or acids of the formula R'COOR in which R' and R independently denote alkyl or alkenyl radicals and the sum of carbon atoms in R' and R is at least 10, preferably at least 20. Di- and trialkyl and alkenyl esters of carboxylic acids can also be used. Particularly preferred fatty esters are mono-, di- and triglycerides, more specifically the mono-, di-, and tri-esters of glycerol and long chain carboxylic acids such as C8-C22 carboxylic acids.

Preferred materials include cocoa butter, palm stearin, sunflower oil, soybean oil and coconut oil.

The oily or fatty material may be present at a level of from 0.05 to 10 wt.-%, preferably from 0.2 to 5 wt.-%, more preferably from 0.5 to 3 wt.-%, based on the total weight of the cosmetic composition.

In a particularly preferred embodiment, the composition of the invention is a shampoo composition.

In at least one embodiment, the shampoo composition comprises from 1 to 99%, preferably from 5 to 95%, more preferably from 10 to 90% by weight of the total composition of water, and from 0.1 to 99%, preferably from 1 to 95%, more preferably from 5 to 90%, often from 5 to 25% by weight of the total composition of a cleansing surfactant. Suitable cleansing surfactants are generally anionic, amphoteric, betaine, or zwitterionic surfactants. For example, the anionic surfactants are alkyl ether or alkyl ether sulfates, such as sodium lauryl sulfate, or other compounds described above.

In at least one embodiment, the shampoo composition comprises one or more further cosmetically acceptable components (F), which can be present in an amount of at least 0.5% by weight, or from 0.5 to 20% by weight, by total weight of the shampoo composition. Preferably, the component (F) is selected from the group consisting of cleansing ingredients, acidity regulators, colorants, conditioning agents, emulsifiers, film formers, fragrances, glossers, humectants, lubricants, moisturizers, pigments, preservatives, hair penetration enhancers, scalp actives, stabilizers, surfactants, thickeners, viscosity modifiers, and combinations thereof. More preferably, the component (F) is selected from the group consisting of surfactants, viscositymodifying polymers and conditioning ingredients. In at least one embodiment, the shampoo composition comprises from 0.05 wt.-% to 5 wt.-% (preferably from 0.1 wt.- % to 2.0 wt.-%, more preferably from 0.1 wt.-% to 1 .0 wt.-%, particularly preferably from 0.1 wt.-% to 0.5 wt.-%) of the piroctone, and at least 0.5% by weight of one or more further components (F) selected from the group consisting of surfactants, polymers, conditioning agents, actives, acidity regulators, lubricants, moisturizers, oils, preservatives, sequestrants, strengthened, sun protectors, and combinations thereof.

In at least one embodiment, the shampoo composition comprises further cosmetically acceptable components (F) being cleansing ingredients. In at least one embodiment, the shampoo composition comprises from 0.05 to 20% by weight of cleansing ingredients, based on the total weight of the shampoo composition. In at least one embodiment of the shampoo composition, the level of cleansing ingredient is from 1 % to 20% by weight, preferably from 5% to 18%, more preferably from 8% to 16%, based on the total weight of the shampoo composition. In at least one embodiment, the cleansing ingredient is selected from the group consisting of non-polymeric surfactants, saponins, polymeric surfactants, and combinations thereof. Preferably, the cleansing ingredient comprises or consists of surfactants.

In at least one embodiment, the shampoo composition comprises from 0.05 wt.-% to 5 wt.-% (preferably from 0.1 wt.-% to 2.0 wt.-%, more preferably from 0.1 wt.-% to 1.0 wt.-%, particularly preferably from 0.1 wt.-% to 0.5 wt.-%) of the piroctone, and at least 0.5 % by weight of surfactants, preferably cleansing anionic or non-ionic surfactants, such as sodium laureth sulphate, sodium lauryl sulphate, ammonium laureth sulphate, ammonium lauryl sulphate, olefin sulfonates, olefin sulfates, laureth- 3 or 4, cocamide DEA, glucosides, cocam idopropyl betaine, coco betaine, cocoamphodipropionate, sodium methyl 2-sulfolaurate and other laurates, sulfoacetates, sulfosuccinates, lactylates, sultaines, caprylates/ caprates, isethionates, glutamates, taurates, sarcosinates, glucamides, and combinations thereof.

In at least one embodiment, the shampoo composition is silicone-free. In at least one embodiment, the shampoo composition is sulfate-free. In at least one embodiment, the shampoo composition is silicone-free and sulfate-free.

In at least one embodiment, the shampoo composition comprises, based on the total weight of the shampoo composition:

(i) from 0.05 wt.-% to 5 wt.-%, preferably from 0.1 wt.-% to 2.0 wt.-%, more preferably from 0.1 wt.-% to 1 .0 wt.-%, particularly preferably from 0.1 wt.-% to 0.5 wt.-% of the piroctone;

(ii) from 5 wt.-% to 20 wt.-% of one or more anionic surfactants;

(iii) at least 50 wt.-% water; and

(iv) at least one further cosmetically acceptable component (F) selected from the group consisting of silicone, cationic polymer, rheology modifying agent, and an amphoteric or zwitterionic surfactant.

(ii) from 5 wt.-% to 20 wt.-% of one or more anionic surfactants;

(iii) at least 50 wt.-% water;

(iv) at least one further component selected from the group consisting of silicone, cationic polymer, rheology modifying agent, and an amphoteric or zwitterionic surfactant; and

(v) at least one further cosmetically acceptable component (F). In at least one embodiment, the shampoo composition consists of, based on the total weight of the shampoo composition:

(ii) from 5 wt.-% to 20 wt.-% of one or more anionic surfactants;

(iii) at least 50 wt.-% water;

(v) at least one further cosmetically acceptable component (F) selected from the group consisting of conditioning agents, such as panthenol, panthenyl ethyl ether, proteins, hydrolysed proteins (preferably of vegetable or animal origin, for example hydrolysed collagen or hydrolysed keratin), nutrients; antioxidants, such as vitamin E; emollients, such as PPG-3 myristyl ether, trimethyl pentanol hydroxyethyl ether; hairfixative polymers such as amphoteric fixative polymers, cationic fixative polymers, anionic fixative polymers, non-ionic fixative polymers, and silicone grafted copolymers; preservatives such as benzyl alcohol, methyl paraben, propyl paraben and imidazolidinyl urea; pH adjusting agents, such as citric acid, sodium citrate, succinic acid, phosphoric acid, sodium hydroxide, sodium carbonate; salts, in general, such as potassium acetate and sodium chloride; coloring agents; hair oxidizing (bleaching) agents, such as hydrogen peroxide, perborate and persulfate salts; hair reducing agents, such as the thioglycolates; perfumes; and sequestering agents, such as disodium ethylene-diamine tetraacetate.

The cosmetic composition of the invention can be manufactured by methods known in the art. For example, the cosmetic composition of the invention can be manufactured by mixing its ingredients. For example, the piroctone can be mixed with the other ingredients of the cosmetic composition of the invention.

The present invention also relates to the use of crystallized or precipitated piroctone obtained by the process of the present invention or piroctone particles of the present invention as an anti-dandruff agent or as a preservative. In preferred embodiments, the invention relates to the use of crystallized or precipitated piroctone obtained by the process of the present invention or piroctone particles of the present invention as an anti-dandruff agent. In preferred embodiments, the invention relates to the use of crystallized or precipitated piroctone obtained by the process of the present invention or piroctone particles of the present invention as a preservative.

Particularly preferably, the piroctone is incorporated into a cosmetic composition.

Preferably, the cosmetic composition is a shampoo composition or hair conditioner composition. More preferably, the cosmetic composition is a shampoo composition, particularly preferably an anti-dandruff shampoo composition. Also more preferably, the cosmetic composition of the invention is a hair conditioner composition.

Preferably, the dandruff is caused by dandruff-causing organisms, more preferably Malassezia species, even more preferably Malassezia furfur and/or Malassezia globosa, particularly preferably Malassezia furfur, also particularly preferably Malassezia globosa.

The present invention also relates to a method of treating hair and/or scalp, comprising: a) applying a shampoo composition and/or hair conditioner composition (preferably shampoo composition) as described herein onto wet hair and/or scalp and then b) removing the shampoo composition and/or hair conditioner composition (preferably shampoo composition) from the hair and/or scalp.

The present invention also relates to a process for the preparation of piroctone olamine, comprising the following steps: i) Reacting pure piroctone with monoethanolamine in a solvent to obtain a piroctone olamine-containing solution; and ii) Crystallizing or precipitating piroctone olamine from the piroctone olamine- containing solution obtained in step i).

In one embodiment, pure piroctone preferably refers to piroctone having a purity of at least 90 wt.-%, more preferably at least 92 wt.-%, more preferably at least 94 wt.-%, even more preferably at least 96 wt.-%, even more preferably at least 97 wt.-%, particularly preferably at least 98 wt.-%, based on the total weight of the pure piroctone.

In one embodiment, pure piroctone preferably refers to piroctone containing not more than 10 wt.-%, more preferably not more than 8 wt.-%, more preferably not more than 6 wt.-%, even more preferably not more than 4 wt.-%, even more preferably not more than 3 wt.-%, particularly preferably not more than 2 wt.-%, of impurities, based on the total weight of the pure piroctone.

Advantageously, using pure piroctone in such a process leads to higher yields and higher purities of piroctone olamine.

According to step i), pure piroctone is reacted with monoethanolamine in a solvent to obtain a piroctone olamine-containing solution.

Preferably, the solvent in step i) is selected from heptane, hexane, cyclohexane, methylcyclohexane, dimethylcyclohexane, toluene, benzene, methylene chloride, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tertbutanol, tert-amyl alcohol, dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, acetonitrile, 2-aminopyridine, ethyl acetate, methyl tert-butyl ether, dibutyl ether, diisopropyl ether, water, and mixtures thereof.

More preferably, the solvent in step i) is selected from heptane, hexane, cyclohexane, methylcyclohexane, dimethylcyclohexane, methanol, ethanol, n- propanol, isopropanol, n-butanol, isobutanol, sec-butanol, ethyl acetate, methyl tertbutyl ether, dibutyl ether, diisopropyl ether, and mixtures thereof.

Even more preferably, the solvent in step i) is selected from heptane, isopropanol, ethyl acetate, methyl tert-butyl ether, and mixtures thereof. Particularly preferably, the solvent in step i) is selected from heptane, isopropanol, methyl tert-butyl ether, and mixtures thereof. In preferred embodiments, step i) is carried out at a temperature in the range of from 30 to 100 °C, preferably from 50 to 90 °C, more preferably from 60 to 85 °C, particularly preferably from 70 to 80 °C.

Preferably, the molar ratio of pure piroctone to monoethanolamine is from 1 .0:1.0 to 1 .0:1.5, more preferably from 1.0:1 .0 to 1.0:1 .2, even more preferably from 1 .0:1.0 to 1.0: 1.1 , particularly preferably from 1.0: 1.0 to 1.0:1.05.

According to step ii), piroctone olamine is crystallized or precipitated from the piroctone olamine-containing solution obtained in step i).

In preferred embodiments, the piroctone olamine in step ii) is crystallized or precipitated by cooling the piroctone olamine-containing solution to a temperature in the range of from -5 to 50 °C, preferably from 0 to 35 °C, more preferably from 0 to 25 °C, particularly preferably from 0 to 20 °C. In preferred embodiments, the piroctone olamine in step ii) is crystallized or precipitated by cooling the piroctone olamine-containing solution to a temperature in the range of from -5 to 20 °C, preferably from 0 to 15 °C, more preferably from 0 to 10 °C, particularly preferably from 0 to 5 °C. In preferred embodiments, the piroctone olamine in step ii) is crystallized or precipitated by cooling the piroctone olamine-containing solution to a temperature in the range of from 0 to 35 °C, preferably from 5 to 30 °C, more preferably from 10 to 25 °C, particularly preferably from 15 to 20 °C.

In preferred embodiments, the crystallized or precipitated piroctone is isolated by filtration. Filtration may be followed by washing with a solvent (preferably the solvent used in step i)) and drying.

If not stated otherwise, all percentages are by weight (w/w) of the total composition. If not stated otherwise, all ratios are weight ratios, “wt.%” means percentage by weight. “QS” or “QSP” means sufficient quantity for 100% or for 100g. “Molecular weight” or “M.Wt.” or “MW” and grammatical equivalents mean the number average molecular weight, if not stated otherwise. The invention is further illustrated by the following examples, without being limited thereby.

Examples

Piroctone Olamine as used herein is also known as piroctone ethanolamine. The chemical name for Piroctone Olamine is the monoethanolamine salt of 1 -hydroxy-4- methyl-6-(2,4,4-trimethylpentyl)-2(1 H)-pyridone. Hence, Piroctone Olamine is the monoethanolamine salt of piroctone.

Examples 1 to 4

Crude piroctone was prepared as follows:

1 molar equivalent of pyron (50 g) was reacted with 1.44 molar equivalents of hydroxylamine sulfate in the presence of 1 .44 molar equivalents of sodium carbonate in toluene (50 ml) along with water (1 % of batch size). Step-wise heating of reaction mixture to be performed to control the reaction temperature, i.e., slowly heated the reaction mixture to attain 65-70°C (Obs.: Exotherm) & maintained for 3 h, followed by heating to 80°C (Obs.: Endotherm), followed by heating to 90-95°C & maintained for 12 hrs. Cooled the reaction mixture to 70-75°C & quenched with water, separated the organic layer and distilled off the solvent completely till the moisture content is not more than 0.8% to obtain crude piroctone (as residue).

Example 1 : Crude piroctone (residue, 50g) dissolved in heptane (1V, 50 mL) at a temperature of 70-75 °C, cooled to 0-5°C, filtered, washed wet cake with heptane (2V, 100 mL) & dried.

Example 2: Crude piroctone (residue, 50g) dissolved in heptane (3V, 150 mL) at a temperature of 70-75 °C, cooled to 15-20°C, filtered, washed wet cake with heptane (1V, 50 mL) & dried

Example 3: Crude piroctone (residue, 25g) dissolved in heptane (5V, 125 mL) at a temperature of 70-75 °C, cooled to 15-20°C, filtered, washed wet cake with heptane (1V, 25 mL) & dried.

Example 4: Crude piroctone (residue, 50g) dissolved in heptane (5V, 250 mL) at a temperature of 70-75 °C, cooled to 15-20°C, filtered, washed wet cake with heptane (1V, 50 mL) & dried.

The results are given in the following Table:

Key: ND = not determined

The particle size distribution (PSD) was determined as follows: PSD instrument: Malvern Mastersizer 3000. Sample preparation and PSD measurement: Desired quantity of about 1 g is put into sample hopper unit and measurement is started with obscuration between 0.5% to 1.5%.

PSD measurements: Every sample is analyzed twice. The values given in the above Table are averages of the two measurements.

The solubility of the piroctone of Examples 1 to 4 was tested as follows:

0.5 g Piroctone are dispersed in approx. 10 g water (demineralized). In a next step approx. 45 g Genapol LRO Liquid (which is a surfactant) is added and the solution stirred at approx. 300 rpm. The samples are checked visually, and the time measured until the solution is clear and all solid dissolved.

The dissolution times are given in the following Table:

These Examples show that the piroctone of the present invention is soluble in a surfactant-containing formulation. A dissolution time of 30-35 min in such a formulation is a good result for piroctone. A dissolution time of 20-25 min is even better.

Example compositions

Example 5

Cosmetic compositions (ingredients are given in wt%)

Example 6

Cosmetic compositions (ingredients are given in wt%)

Example 7

Cosmetic compositions (ingredients are given in wt%)

Example 8

Hair conditioner compositions

Example 9

Hair conditioner compositions

Genadvance® Repair: Clariant, INCI = Quaternium-98

Genadvance® Hydra: Clariant, INCI = Lauryl/Myristyl Polyricinoleate & Glycerin

Example 10

Hair conditioner compositions

Genadvance® Hydra: Clariant, INCI = Lauryl/Myristyl Polyricinoleate & Glycerin

Example 11

Shampoo compositions

Example 12

Shampoo compositions

Example 13

Shampoo compositions

Example 14

Shampoo compositions

Example 15

Shampoo compositions Example 16

Shampoo compositions

Example 17

Shampoo compositions

Example 18

Shampoo compositions

Example 19

Shampoo compositions

Example 20

Shampoo compositions

Example 21

Shampoo compositions

Example 22

Shampoo compositions

Example 23

Shampoo compositions

Example 24

Shampoo compositions Example 25

Bar shampoos

Examples 26 to 29

Charged Solvent (as specified in the following Table) (2V, 100 mL) to crude piroctone and stirred at 70-75°C (Obs.: clear solution). Cooled the reaction mixture slowly to room temperature followed by 15-20°C and maintained for 2 h at 15-20°C. Solids were filtered & washed with chilled Solvent (1V, 50 mL) (as specified in the following Table) & dried.

Examples 30 to 32

Preparation of piroctone olamine from pure piroctone

Example 30:

- Pure piroctone was dissolved in heptane at 70-80°C,

- dropwise addition of monoethanolamine at 70-80°C,

- maintained at 70-80°C for 2 hours,

- cooled to RT,

- cooled to 0-5°C and filtered the mass at 0-5°C.

Example 31 :

The reaction was also carried out using methyl tert-butyl ether (MTBE) as the solvent. In this case the pure piroctone was dissolved in MTBE at room temperature.

Example 32:

The reaction was also carried out using isopropanol (IPA) as the solvent. In this case the pure piroctone was dissolved in IPA at room temperature.

Claims

1 . A process for the crystallization or precipitation of piroctone, comprising the following steps: a) Dissolving a piroctone-containing product in a solvent; b) Cooling the solution; and c) Isolating crystallized or precipitated piroctone.

2. The process according to claim 1 , wherein the solvent in step a) is selected from heptane, hexane, cyclohexane, methylcyclohexane, dimethylcyclohexane, toluene, benzene, methylene chloride, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tertbutanol, tert-amyl alcohol, dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, acetonitrile, 2-aminopyridine, methyl tert-butyl ether, dibutyl ether, diisopropyl ether, water, and mixtures thereof.

3. The process according to claim 1 or 2, wherein in step a) at least 50 ml, preferably at least 100 ml, more preferably at least 300 ml, particularly preferably at least 500 ml, of solvent is used per 100 g of the piroctone- containing product.

4. The process according to any of claims 1 to 3, wherein the piroctone- containing product in step a) is dissolved in the solvent at a temperature in the range of from 30 to 100 °C, preferably from 40 to 90 °C, more preferably from 50 to 80 °C, particularly preferably from 60 to 80 °C.

5. The process according to any of claims 1 to 4, wherein the solution in step b) is cooled to a temperature in the range of from -5 to 50 °C, preferably from 0 to 35 °C, more preferably from 0 to 25 °C, particularly preferably from 0 to 20 °C.

6. The process according to any of claims 1 to 5, wherein the piroctone- containing product used in step a) is prepared by reacting pyron with hydroxylamine or a hydroxylammonium compound, preferably a hydroxylammonium compound. The process according to any of claims 1 to 6, wherein the crystallized or precipitated piroctone has a dgo of 250 pm or less, preferably 200 pm or less, more preferably 150 pm or less, particularly preferably 100 pm or less. The process according to any of claims 1 to 7, wherein the crystallized or precipitated piroctone has a dso of 90 pm or less, preferably 80 pm or less, more preferably 75 pm or less, particularly preferably 70 pm or less. Piroctone particles having a dgo of 250 pm or less. Piroctone particles according to claim 9, wherein the piroctone particles have a dgo of 200 pm or less, preferably 150 pm or less, particularly preferably 100 pm or less. Piroctone particles according to claim 9 or 10, wherein the piroctone particles have a dso of 90 pm or less, preferably 80 pm or less, more preferably 75 pm or less, particularly preferably 70 pm or less. A process for the preparation of piroctone, comprising the following steps:

2) crystallizing or precipitating piroctone from a solvent S2, with the proviso that, if solvent S2 used in step 2) is heptane, solvent S1 used in step 1 ) is not heptane. The process according to claim 12, wherein the solvent S1 in step 1 ) is selected from heptane, hexane, cyclohexane, methylcyclohexane, dimethylcyclohexane, toluene, benzene, methylene chloride, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tertbutanol, tert-amyl alcohol, dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, acetonitrile, 2-aminopyridine, methyl tert-butyl ether, dibutyl ether, diisopropyl ether, water, and mixtures thereof. The process according to claim 12 or 13, wherein the solvent S2 in step 2) is selected from heptane, hexane, cyclohexane, methylcyclohexane, dimethylcyclohexane, toluene, benzene, methylene chloride, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tertbutanol, tert-amyl alcohol, dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, acetonitrile, 2-aminopyridine, methyl tert-butyl ether, dibutyl ether, diisopropyl ether, water, and mixtures thereof. Use of crystallized or precipitated piroctone obtained by a process as defined in any of claims 1 to 8 or 12 to 14 or piroctone particles as defined in any of claims 9 to 11 for the manufacture of a cosmetic composition, wherein the cosmetic composition is preferably selected from the group consisting of shampoo, hair conditioner, hair tonic, cream rinse, body wash, bubble bath, bath oil, facial cleanser, cleansing mask, cleansing milk, micellar water, makeup remover, cleansing wipes, perfume, soaps, shaving soaps, shaving foams, cleansing foams, face mask, face cream, hand cream and body lotion. Use of crystallized or precipitated piroctone obtained by a process as defined in any of claims 1 to 8 or 12 to 14 or piroctone particles as defined in any of claims 9 to 11 as an anti-dandruff agent or as a preservative. A process for the preparation of piroctone olamine, comprising the following steps: i) Reacting pure piroctone with monoethanolamine in a solvent to obtain a piroctone olamine-containing solution; and ii) Crystallizing or precipitating piroctone olamine from the piroctone olamine-containing solution obtained in step i). The process according to claim 17, wherein the solvent in step i) is selected from heptane, hexane, cyclohexane, methylcyclohexane, dimethylcyclohexane, toluene, benzene, methylene chloride, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tertbutanol, tert-amyl alcohol, dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, acetonitrile, 2-aminopyridine, ethyl acetate, methyl tert-butyl ether, dibutyl ether, diisopropyl ether, water, and mixtures thereof. The process according to claim 17 or 18, wherein step i) is carried out at a temperature in the range of from 30 to 100 °C, preferably from 50 to 90 °C, more preferably from 60 to 85 °C, particularly preferably from 70 to 80 °C. The process according to any of claims 17 to 19, wherein the piroctone olamine in step ii) is crystallized or precipitated by cooling the piroctone olamine-containing solution to a temperature in the range of from -5 to 50 °C, preferably from 0 to 35 °C, more preferably from 0 to 25 °C, particularly preferably from 0 to 20 °C.