WO2025181056A1

WO2025181056A1 - Conditioning agents

Info

Publication number: WO2025181056A1
Application number: PCT/EP2025/054996
Authority: WO
Inventors: Barbara Biasotti; Valentina Langella; Simone MACULAN; Stefano Monti; Rossana COLOMBO
Original assignee: Lamberti SpA
Current assignee: Lamberti SpA
Priority date: 2024-02-26
Filing date: 2025-02-25
Publication date: 2025-09-04
Anticipated expiration: 2026-08-26

Abstract

Conditioning agents comprising: a) from 47 to 88 % by weight of the chloride of 2-hydroxy-3-(trimethylammonium)propyl ether of carboxymethyl tamarind having minimum DS_cat of 0.01 and maximum DS_cat of 0.30, and minimum DS_CM of 0.01 and maximum DS_CM of 0.50, b) from 0.3 to 8.0% by weight of (2,3- dihydroxypropyl)trimethyl ammonium chloride and c) from 5.0 to 33 % by weight of ashes, and personal care and household care compositions containing said conditioning agents.

Description

CONDITIONING AGENTS

FIELD OF THE INVENTION

The present invention relates to conditioning agents comprising from 47 to 88 % by weight of the chloride of 2-hydroxy-3-(trimethylammonium)propyl ether of carboxymethyl tamarind having a minimum DS_cat of 0.01 and a maximum DS_cat of 0.30 and minimum DSCM of 0.01 and a maximum DSCM of 0.50, from 0.3 to 8.0 % by weight of (2,3-dihydroxypropyl)trimethyl ammonium chloride and from 5.0 to 33 % by weight of ashes and to personal care and household care compositions containing said conditioning agents.

PRIOR ART

Cationic polysaccharides, such as cationic galactomannans and xyloglucans, are derivatives of natural origin that are commonly used as industrial additives, due to their conditioning property (i.e. they improve the sensorial characteristics of the substrate to which they are applied on, generally paper, skin, hair or fabric).

This characteristic renders them industrially useful for the preparation of shampoos and hair conditioners, creams and detergents for personal or household care and for softeners conferring a soft touch and antistatic properties to fabrics (see as an example “Conditioning Agents for Hair & Skin”, Ed. R. Schueller and P. Romanowski, Marcel Dekker Inc, NY, 1999). Beside their conditioning power, the capability of these polysaccharides to thicken and regulate the rheology of the solutions in which they are dissolved is also industrially useful. In particular, among cationic polysaccharides, the cationic derivatives of guar gum and cassia gum (which are both galactomannans) have shown good compatibility with the various ingredients of the cosmetic compositions and optimal results in improving the wet and dry combability of hair washed with shampoo formulated therewith. The synthesis of industrially useful cationic derivatives of polysaccharides, generally requires a reaction of cationization agents, in particular of (2,3- epoxypropyl) trimethyl ammonium chloride (EPTAC) or (3-chloro-2- hydroxypropyl)trimethyl ammonium chloride (CHPTAC), with the hydroxyl groups of the polysaccharide, in the presence of alkaline catalysts (such as sodium hydroxide).

(2, 3 -epoxypropyl) trimethyl ammonium chloride and (3-chloro-2- hydroxypropyl)trimethyl ammonium chloride are noxious substances and they must be removed from the cationic polysaccharides for the use in personal care compositions or in formulations that come to direct contact with the skin, such as household care compositions, generally by purification with water and/or solvents. Unfortunately, all these purification procedures involve large quantities of water and solvents, and in some cases, the use of toxic substances such as borax. For these reasons, alternative procedures have been developed.

For example, WO 2014/027120 describes a process for the preparation of conditioners and rheology modifiers comprising cationic galactomannans or xyloglucans, optionally containing further substituents, such as hydroxyalkyl, hydrophobic, carboxyalkyl substituents or combinations thereof, that comprises a second alkaline treatment, which takes place after the cationization reaction with (3-chloro-2-hydroxypropyl)trimethyl ammonium chloride or with (2,3- epoxypropyl) trimethyl ammonium chloride, and converts the noxious residual cationization agent into the non-noxious, beneficial, cosmetically accepted ingredient (2,3-dihydroxypropyl)trimethyl ammonium chloride. Advantageously, it is not necessary to purify the conditioner and rheology modifier obtained from the process of WO 2014/027120 by washing with water or solvents, as they contain less than 0. 15 % by weight of cationizing agent.

Usually, the conditioners and rheology modifiers of WO 2014/027120, besides the cationic polysaccharide, contains from 1% to 10% by weight of (2,3- dihydroxypropyl)trimethyl ammonium chloride, ashes and further minor amounts of non-noxious by-products deriving from the other additional derivatizing reactions, such as glycols and polyglycols deriving from propylene oxide, in amount between 0 to 15 % by weight. Other ingredients that may be present are salts, deriving from the alkaline hydroxide and possibly from the acid which is added to adjust the pH, normally in amount between 1 and 15 % by weight.

However, in some cases, cationic polysaccharides having a degree of substitution in the low or very low range, show poor compatibility with the different ingredients of the cosmetic compositions, in particular with certain surfactants. This leads to a modification of the physical and chemical characteristics of the cosmetic products, decreasing their overall quality, i.e. its functionality and aesthetics.

In addition, over the last years, there has been an increasing pressure towards environmentally friendly, biodegradable products including modified polysaccharides. Unfortunately, the cationic polysaccharides commonly utilized in the field, despite being based on natural raw material, are known as products with reduced biodegradability or not readily-biodegradable and there is a general trend for the industry to switch to other conditioning agents.

WO 2014/027120 is silent about the compatibility with a surfactant system and the biodegradability of these conditioners and rheology modifiers. It is exclusively focused on solving the several technological problems connected with the necessity of adding a purification step to their synthesis and of reducing the production costs. Even more so, considering the difficulties in managing a lot of waste water and/or recycling the solvents.

Now, the Applicant has surprisingly found that conditioning agents based on the chloride of 2-hydroxy-3-(trimethylammonium)propyl ether of carboxymethyl tamarind (cationic CMT), having specific carboxymethyl and cationic degrees of substitution, obtained with the process of WO 2014/027120 show high compatibility with the various ingredients of the cosmetic compositions, even at low or very low degrees of cationic substitution. At the same time, despite their low or very low cationic substitution, they show excellent conditioning performances.

Moreover, these cationic CMT, despite having two different substituents and despite being products which have not been purified by washing with solvents, have a very low content of CHPTAC, EPTAC and sodium monochloroacetate (a skin irrating agent) and have a biodegradability that is comparable to that of the non-carboxymethylated cationic tamarind obtained with same process and better than the cationic galactomannans present in the market.

The above cited WO 2014/027120 does not disclose any specific cationic CMT with beneficial characteristics in terms of compatibility with hair care compositions and biodegradability; in particular WO 2014/027120 does not report any examples of cationic carboxymethyl tamarind at all.

In the present text, with the expression “cationic carboxymethyl tamarind”, we mean the chloride of the 2-hydroxy-3-(trimethylammonium)propyl ether of carboxymethyl tamarind.

In the present text, with the expression “cationic degree of substitution”, (DS_cat) we mean the average number of hydroxyl groups substituted with a cationic group on each anhydroglycosidic unit of the polysaccharide, determined by mass balance between the cationizing agent added to the reaction system and its reaction byproducts.

With the expression “carboxymethyl degree of substitution”, (DSCM) we mean the average number of hydroxyl groups substituted with a carboxymethyl group on each anhydroglycosidic unit of the polysaccharide, determined by mass balance between the carboxymethylating agent added to the reaction system and its reaction by-products.

With the expressions or “personal care compositions” we mean the compositions normally used for personal care, such as hair care products, skin care products and oral care compositions.

The term “biodegradable” in the present specification means that % biodegradation after 28 days (D28) of the conditioning agent of the invention is above 60 % according to the standard method OECD 30 IF.

The term “readily biodegradable” according to the standard method OECD 301F means that the product reaches at least 60% ThOD in a 10-day window beginning when the degree of biodegradation has reached 10% ThOD. The 10-day window must end before day 28 of the test.

DESCRIPTION OF THE INVENTION

It is therefore an object of the present invention a conditioning agent comprising: a) from 47 to 88 % by weight, preferably from 52 to 85 % by weight, of the chloride of 2-hydroxy-3-(trimethylammonium)propyl ether of carboxymethyl tamarind (cationic CMT) having a minimum DS_cat of 0.01 and a maximum DScat of 0.30 and a minimum DSCM of 0.01 and a maximum DSCM of 0.50; b) from 0.3 to 8.0 % by weight of (2,3-dihydroxypropyl)trimethyl ammonium chloride; c) from 5.0 to 33 % by weight of ashes determined at 650 °C; wherein the component b) is a by-product of the cationization reaction and the cationic CMT does not contain other substituents^

Personal care and household care compositions comprising from 0.01 to 10% by weight, based on the total weight of the compositions, of said conditioning agent are other objects of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The conditioning agent of the invention can be prepared according to the process described in WO 2014/027120.

The process can comprise the following steps: I) 100 parts by weight of tamarind gum are reacted with from 0.5 to 50 parts by weight of sodium chloroacetate and with from 1 to 100 parts by weight of (3-chloro-2-hydroxypropyl)trimethyl ammonium chloride or of (2,3-epoxypropyl)trimethyl ammonium chloride, in the presence of from 1 to 150 parts by weight of sodium hydroxide (or equivalent amount of another alkaline hydroxide) and from 5 to 550 parts of water or of a water/alcohol mixture containing from 1 to 100% by weight of water; II) from 0.1 to 50 parts by weight of sodium hydroxide (or equivalent amount of another alkaline hydroxide) are added to the obtained mixture and the mass is stirred for from 10 to 300 minutes, preferably from 60 to 150 minutes, at a temperature comprised between 30 and 90 °C, preferably between 45 and 80 °C; III) optionally the pH of the mixture is corrected with an acid; IV) the product obtained from Step II) or III) is directly dried and milled.

According to a preferred embodiment of the present invention, in step I) of the process, from 1 to 40 parts by weight of sodium chloroacetate, from 2 to 60 parts by weight of (3-chloro-2-hydroxypropyl)trimethyl ammonium chloride and from 1.0 to 70 parts by weight of sodium hydroxide are added.

The alcohol useful for the process of the invention is preferably ethanol, isopropanol, or mixtures thereof. Preferably, in Step I) of the process of the invention, from 50 to 450 parts by weight of water or of water/alcohol mixture each 100 parts by weight tamarind are used.

Advantageously, in step I), tamarind gum, the alkaline hydroxide, sodium chloroacetate and the cationizing agent are reacted for about 1 to 6 hours at temperature from about 40 to about 80 °C, before step II) takes place.

Preferably, the alkaline hydroxide is added to tamarind gum that has been premixed with the water or with the water/alcohol mixture and stirred for about 15 to 60 minutes; subsequently, both the derivatizing agents are added and reacted at about 40 to 70 °C for about 1 to 6 hours, before Step II) takes place.

The derivatization reactions, i.e. carboxymethylation and cationization, can be made in two steps and can follow any order.

By way of example, cationic substituent may be introduced in the last derivatization step, after the carboxymethylation step have occurred. This sequence is preferred.

Tamarind gum is a well-known xyloglucan. Xyloglucans are hemicellulose that occur in the primary cell wall of all vascular plants.

Tamarind (Tamarindus Indica) is a leguminous evergreen tall tree produced in the tropics. Tamarind gum (tamarind powder or tamarind kernel powder) is obtained by extracting and purifying the powder obtained by grinding the seeds of tamarind. Its backbone consists of D-glucose units joined with (l-4)-beta- linkages similar to that of cellulose, with a side chain of single xylose unit attached to every second, third and fourth of D-glucose unit through alfa-D-(l-6) linkage. One galactose unit is attached to one of the xylose units through beta-D-(l-2) linkage. The molar ratio between glucose, galactose and xylose is about 3: 1:2.

There are basically two different grades of tamarind gum which are used in specific industrial applications like textile and pharmaceutical industries: oiled tamarind kernel powder and the de-oiled tamarind kernel powder. Both are useful for the realization of the present invention.

In a preferred embodiment of the invention the tamarind, gum is oiled tamarind kernel powder.

In another preferred embodiment of the invention, the tamarind gum is de-oiled tamarind kernel powder.

Typically, the tamarind gum is in the form of a powder having particles size of from 100 to 400 mesh, preferably from 100 to 300 mesh.

The tamarind gum suitable for obtaining the cationic carboxymethyl derivative of the invention has preferably a Brookfield RVT viscosity, measured at 25 °C and 20 rpm on a 4.0 % by weight water solution, comprised between 50 and 10,000 mPa*s and a weight average molecular weight (M_w) typically of between 100,000 and 1,000,000 Dalton.

In a preferred embodiment of the invention, from 0.1 to 30 parts by weight, preferably from 5 to 25 parts by weight, of sodium hydroxide (or equivalent amount of other alkaline hydroxide) each 100 parts of tamarind gum are added to the reaction mixture in Step II).

The characterizing step of the procedure of the invention is Step II). Step II) can be performed at any time after the cationization of the tamarind, but preferably it is performed after both the derivatization reactions have been carried out.

After Step II), the pH of conditioning agent can opportunely be adjusted. Any acid may be selected to adjust the pH of the reaction mixture, including inorganic acids such as hydrochloric acid, carbon dioxide and sulfuric acid, or organic acids, such as acetic acid, propionic acid, gluconic acid, lactic acid, oxalic acid, tartaric acid, malic acid, fumaric acid, malonic acid, citric acid and succinic acid. Organic acids are preferred. In preferred embodiments, acetic acid, tartaric acid, lactic acid or citric acid are used to adjust the pH of the conditioning agent. The amount of acid used is the amount which is necessary to reach the desired pH value, which is usually from 4 to 11.

Finally, the conditioning agent is dried and recovered using means known in the art. Examples of such means include air drying, fluidized bed drying, filtering, centrifuging, addition of solvents, freeze drying and the like. The use of fluidized bed drying is particularly recommended.

In some embodiment of the invention, the cationic CMT is depolymerized by known methods, such as oxidation, for example with alkali or hydrogen peroxide, or by other depolymerization reactions, such as enzymatic or thermal depolymerization, or acid hydrolysis.

In a preferred embodiment, the depolymerized cationic CMT of the invention is prepared by reducing the molecular weight after the cationization.

According to the present invention, no purification by washing with water or solvents is contemplated in the disclosed procedure that provides the conditioning agent of the invention. As a consequence the conditioning agent, besides the cationic CMT, contains all the by-products deriving from the cationization and carboxymethylation reaction, e.g. (2,3-dihydroxypropyl)trimethyl ammonium salt, glycolate salts and other inorganic and/or organic salts.

According to the invention, the cationic CMT contains only cationic and carboxymethyl substituents.

The cationic CMT of the invention has a minimum DS_cat of 0.01, preferably of 0.02, more preferably of 0.04, most preferably of 0.06, and a maximum DS_cat of 0.30, preferably of 0.25, more preferably of 0.15, most preferably of 0.10. The cationic CMT of the invention has a minimum DSCM of 0.01, preferably of 0.02, more preferably of 0.05, most preferably of 0.08 and a maximum DSCM of 0.50, preferably of 0.30, more preferably of 0.25.

Any range of DS obtainable from the combination of the different minimums and maximums are suitable for the realization of the present invention.

In a preferred embodiment, the cationic CMT of the invention has a minimum DScat of 0.02 and a maximum DScat of 0.25 and a minimum DSCM of 0.02 and a maximum DSCM of 0.30.

In a more preferred embodiment, the cationic CMT of the invention has a minimum DS_cat of 0.04 and a maximum DS_cat of 0.25 and a minimum DSCM of 0.05 and a maximum DSCM of 0.30. At the end of the preparation procedure, the conditioning agent of the invention contains from 47 to 88 % by weight, preferably from 52 to 85 % by weight, of the cationic CMT.

The conditioning agent has an ash content (determined at 650 °C, i.e. by incineration in a muffled furnace), related to the content of inorganic substances, from 5.0 to 33 % by weight, preferably from 8.0 to 30 % by weight, more preferably from 10.0 to 27 % by weight.

The conditioning agent further contains from 0.3 to 8.0 % by weight, preferably from 0.3 to 7.0 % by weight, more preferably from 0.3 to 5.0 % by weight, most preferably from 0.3 to 3.5 % by weight, of (2,3-dihydroxypropyl)trimethyl ammonium chloride, derived from (3-chloro-2-hydroxypropyl)trimethyl ammonium chloride or (2,3-epoxypropyl)trimethyl ammonium chloride, that is itself a cosmetic ingredient known with the INCI name of Dihydroxypropyl Trimonium Chloride.

The conditioning agent can also contain from 0.05 to 5.0 % by weight, preferably from 0.05 to 3.0 % by weight, more preferably from 0.05 to 2.5 % by weight of sodium glycolate.

Advantageously, the conditioning agent of the invention has a residual content of (3-chloro-2-hydroxypropyl)trimethyl ammonium chloride or (2,3 -epoxypropyl) trimethyl ammonium chloride below 200 ppm, preferably below 100 ppm, more preferably below 50 ppm, most preferably below 30 ppm; even more advantageously, the conditioning agent of the invention also has a residual content of sodium monochloroacetate below 0.1 wt%, preferably below 0.07 wt%, more preferably below 0.04 wt%, most preferably equal to or below 0.01 wt%.

The conditioning agent may further contain some residual water, normally between 1.5 and 12.0 % by weight, preferably between 2.0 and 10.0 % by weight. It has been surprisingly found that conditioning agents according to the invention comprising the cationic CMT having a minimum DS_cat of 0.01 or 0.02 or 0.04 and a maximum DS_cat of 0.15 and a minimum DSCM of 0.01 or 0.02 or 0.05 and a maximum DSCM of 0.25 are “biodegradable” according to the standard method OECD 30 IF.

It is therefore a preferred object of the invention, a conditioning agent comprising: a) from 47 to 88 % by weight, of cationic CMT having a minimum DS_cat of 0.01 or 0.02 or 0.04 and a maximum DS_cat of 0.15 and a minimum DSCM of 0.01 or 0.02 or 0.05 and a maximum DSCM of 0.25; b) from 0.3 to 7.0 % by weight of (2,3-dihydroxypropyl)trimethyl ammonium chloride; c) from 8.0 to 30 % by weight of ashes determined at 650 °C; wherein the component b) is a by-product of the cationization reaction and the cationic CMT does not contain other substituents.

Another object of the invention is a conditioning agent comprising: a) from 47 to 88 % by weight, of cationic CMT having a minimum DS_cat of 0.01 or 0.02 or 0.04 and a maximum DS_cat of 0.15 and a minimum DSCM of 0.01 or 0.02 or 0.05 and a maximum DSCM of 0.25; b) from 0.3 to 7.0 % by weight of (2,3-dihydroxypropyl)trimethyl ammonium chloride; c) from 8.0 to 30 % by weight of ashes determined at 650 °C. It has been further found that conditioning agents according to the invention comprising the cationic CMT having a minimum DS_cat of 0.01 or 0.02 or 0.04 and a maximum DS_cat of 0.10 and a minimum DSCM of 0.01 or 0.02 or 0.05 and a maximum DSCM of 0.25 are “readily biodegradable” according to the standard method OECD 30 IF and despite the very low cationic substitution possesses very good conditioning properties that makes it particularly preferred for use in the preparation of biodegradable personal care and household care compositions.

It is therefore a more preferred object of the invention, a conditioning agent comprising: a) from 47 to 88 % by weight of cationic CMT having a minimum DS_cat of 0.01 or 0.02 or 0.04 and a maximum DS_cat of 0.10 and a minimum DSCM of 0.01 or 0.02 or 0.05 and a maximum DSCM of 0.25; b) from 0.3 to 5.0 % by weight of (2,3-dihydroxypropyl)trimethyl ammonium chloride; c) from 10.0 to 27 % by weight of ashes determined at 650 °C; wherein the component b) is a by-product of the cationization reaction and the cationic CMT does not contain other substituents.

Another preferred object of the invention is a conditioning agent comprising: a) from 47 to 88 % by weight of cationic CMT having a minimum DS_cat of 0.01 or 0.02 or 0.04 and a maximum DS_cat of 0.10 and a minimum DSCM of 0.01 or 0.02 or 0.05 and a maximum DSCM of 0.25; b) from 0.3 to 5.0 % by weight of (2,3-dihydroxypropyl)trimethyl ammonium chloride; c) from 10.0 to 27 % by weight of ashes determined at 650 °C.

The conditioning agent of the invention has a Brookfield RVT viscosity of from 15 to 4000 mPa*s, preferably from 50 to 3000 mPa*s, at 4.0 % by weight in water, 20 rpm and 20 °C. If the cationic CMT is depolymerized, the conditioning agent has a Brookfield RVT viscosity of from 15 to 1000 mPa*s, preferably from 50 to 700 mPa*s, at 4.0 % by weight in water, 20 °C, 20 rpm.

Advantageously, the conditioning agent of the invention is also devoid of glyoxal, boron, or other crosslinking agents.

According to a preferred embodiment of the present invention, the conditioning agent shows a % biodegradation after 28 days above 60 %, preferably above 70 %, more preferably above 75 %, according to the standard method OECD 30 IF.

The conditioning agent of the invention can be used, as biodegradable ingredient, for the preparation of personal care and household care compositions for its stabilizing and conditioning properties. These compositions are stable for at least 3 months at 40 °C, even in the presence of anionic surfactants, such as sodium laureth sulfate, at a concentration of 5.0 wt% or higher.

The conditioning agent of the invention can be used as ingredient in several compositions such as shampoos, bath and shower gels, skin cleansers, hair conditioners, hair masks and treatments, skin care products, household care detergents and softeners. The properties of the conditioning agent are fully exploited especially in hair-care compositions, where it combines its capability of binding through the positive charges to substrates having weak negative charges, together with the capability to thicken and to regulate the rheology of water solutions.

The personal care and household care compositions of the present invention may be in the form of solution, emulsion, dispersion, gel, cream, paste, bar, powder or wet wipe.

Preferably, the personal care and household care compositions of the invention comprise from 0.03 to 5.0 % by weight, more preferably from 0.05 and 2.0 % by weight, of said conditioning agent, based on the total weight of the compositions. Specific examples of personal care compositions of the invention are hair- and skin-cleansing compositions, shampoos, 2-in-l shampoos, body and shower gels, bath foams, cleansing soaps and bars, cleansing powders and concentrates, makeup removers, impregnating liquids for wet wipes, cleansing foams and mousses, liquid soaps, scrubbing/peeling formulations, dentifrices, shaving creams and other products for similar applications.

The household care compositions of the invention include, but are not limited to: hard surface cleaning liquids or gels, bars, emulsions and liquid compositions, dry or damp dusting, cleaning and/or disinfecting wipes, fabric detergents and softeners.

The conditioning agents of the invention are easily soluble in water, and their thickening effect is not impaired by the presence of surfactants, which are normally present in personal care and household care compositions.

The personal care and household care compositions of the invention can comprise from 0.5 to 70 % by weight, preferably from 1 to 60 % by weight, more preferably from 2 to 50 % by weight, of at least one surfactant selected among anionic surfactants, amphoteric surfactants, cationic surfactants, zwitterionic surfactants, non-ionic surfactants, and mixture thereof.

The personal care and household care compositions of the invention can comprise further additives commonly used in the field. Examples of these additives are: humectants, emollients, consistency factors and sensorial additives, chelating agents, solubilizers; fillers, pigments, dyes; perfumes, fragrances and/or essential oils; water and/or oil soluble vitamins or derivatives or precursors; antioxidants and/or preservatives; pearlescent agents; peeling and/or scrubbing agents; plant extracts, particularly water soluble plant extracts; hydroxy-, particularly alphahydroxy, and/or polyunsaturated acids; phospholipids; proteins and/or amino acids and/or derivatives; electrolytes; NMF (natural moisturising factor); foam boosters and/or stabilisers e.g. mono- and/or di-ethanolamides and/or amine oxides; and sucrose esters.

Also, the household care compositions comprise the ingredients conventionally used in the field, such as, sequestering agents, antioxidants, preserving agents, basifying or acidifying agents, fragrances, fillers, dyestuffs, thickeners and rheology modifier, other polymers and emulsifiers, gelling agents, surfactants and foaming agents, solubilizers, oils and waxes, defoamers and solvents, deodorizers, insecticides and insect repellents, bactericides, cleaning agents, disinfectants, softening agents, and enzymes.

The personal care and household care compositions of the invention can also contain an acceptable liquid medium, which, according to the final use of the composition, is compatible with any keratin substance, such as skin, nails, hair, wool and the like, or with any surface.

The acceptable medium may represent from 5% to 98% of the total weight of the compositions. The typical acceptable medium is water.

The aqueous personal care and household care compositions of the invention may comprise from 5 to 98 wt%, or from 10 to 95 wt% of water, preferably from 20 to 80 wt% of water.

Advantageously, the personal care and household care aqueous compositions comprising from 0.01 to 10% by weight, based on the total weight of the compositions, of the conditioning agents of the present description and from 2 to 10 wt% of anionic surfactants, such as sodium laureth sulfate, are stable for at least 3 months at 40 °C.

By “stable compositions”, we mean compositions that do not undergo phase separation or sedimentation, as can be seen visually.

Acceptable organic solvents may replace or partly substitute the water.

The organic solvents may be hydrophilic organic solvents, lipophilic organic solvents, amphiphilic solvents or mixtures thereof.

Examples of hydrophilic organic solvents are linear or branched lower monoalcohols having from 1 to 8 carbon atoms, such as ethanol, propanol, butanol, isopropanol and isobutanol; polyethylene glycols having from 6 to 80 ethylene oxides; polyols such as propylene glycol, butylene glycol, glycerol and sorbitol; mono- or dialkyl isosorbide in which the alkyl groups have from 1 to 5 carbon atoms, such as dimethyl isosorbide; glycol ethers such as diethylene glycol monomethyl or monoethyl ether or dipropylene glycol methyl ether.

Among the utilisable amphiphilic organic solvents, we cite polyols such as polypropylene glycol (PPG) derivatives, such as fatty acid esters of polypropylene glycol and fatty alcohol ethers of PPG.

Utilisable lipophilic organic solvents are, for example, fatty esters such as diisopropyl adipate, dioctyl adipate and alkyl benzoates.

The personal care and household care compositions of the invention may contain an oil, such as a mineral oil, a vegetable oil, an animal oil, a synthetic oil, silicone oils and mixture thereof. Examples of utilizable oils are paraffins, liquid petroleum jelly, jojoba oil, coconut oil, sweet almond oil, olive oil, rapeseed oil, castor oil, sesame oil, avocado oil, groundnut oil, isoparaffins, amodimethicones, dimethiconols, cyclopentasiloxanes, and mixture thereof.

To better illustrate the invention, the following Examples are reported to show the preparation of various conditioning agents according to the invention and the effect of their addition in exemplary personal care compositions.

The examples are merely set forth for illustrative purposes, all parts and percentages being by weight, unless otherwise indicated.

EXAMPLES

Characterization Methods

The determination of the (2,3-dihydroxypropyl)trimethyl ammonium chloride (DHPTAC) content was carried out by means of ion exchange chromatography. An ICS 5000 DC ion chromatograph (Thermo Scientific), equipped with a conductimetric detector, an lonPac CG-12A, 50 x 4.0 mm pre-column and an lonPac CS-12A, 250 x 4.0 mm column, was used. A 35 min gradient elution from 95/5 to 75/25 of water/0.1 M methane sulfonic acid aqueous solution at a flow of 1.0 ml/min was used. The sample solutions were prepared by accurately weighing about 100.0 mg of conditioning agent in a 100.0 ml flask, adding 1.0 ml of methanol in order to disperse the powder and then diluting to volume with water. The solutions were stirred for 30 min with magnetic stirrer and subsequently filtered. Solutions of DHPTAC at known concentration were used as calibration standard.

The determination of the sodium monochloroacetate (NaMCA) content was carried out by means of ion exchange chromatography. An ICS 5000 DC ion chromatograph (Thermo Scientific), equipped with a conductimetric detector, an lonPac AG 94 x 50 mm guard column and an lonPac AS9-HC 4 x 250 mm column (Thermo Scientific) was used. The columns were maintained at a temperature of 40 °C. The eluent was a NaiCCb 8.00 mM + NaHCCb 1.00 mM solution at a flow rate of 1,0 ml/min. The sample solutions were prepared by accurately weighing about 350.0 mg of conditioning agent in a 10.0 ml flask and adding 4.0 ml of water and 0.20 ml of Primafast 200 (acid cellulase). The solutions were stirred with a magnetic stirrer until complete dissolution and then diluted to volume with water. 5.00 ml of these sample solutions were diluted 15.0 ml of with water and then filtered on a 0.45 micron membrane filter. Solutions of monochloroacetic acid at known concentration were used as calibration standard.

The determination of the (3-chloro-2-hydroxypropyl)trimethyl ammonium chloride (CHPTAC) content was carried out by means of liquid chromatography. An UPLC Aquity UPLC H-Class Plus (Waters) equipped with a mass detector QDa, an Acquity BEH HILIC VanGuard pre-column and an Acquity BEH HILIC column 2.1 x 100mm, E7um, was used. The eluent was a mixture of 15/85 (v/v) 40mM Ammonium Acetate in H2O/Acetonitrile, containing 0.1% (v/v) of Formic Acid, at a flow of 0.6 ml/min. The sample solutions were prepared by accurately weighing about 100.0 mg of conditioning agent and diluting to volume with a mixture 60/40 (v/v) of Acetonitrile/EEO containing 0.1% (v/v) of Formic Acid and the internal standard. (3-Chloro-2-hydroxypropyl)trimethyl-d9-ammonium chloride was used as internal standard.

The determination of the sodium glycolate content was carried out by means of gas chromatography after derivatization. A GC-Trace 1300 (Thermo Fisher), equipped with an Al 1310 autosampler, a FID detector and a CP Sil 5 CB 30 m x 0,32mm 1 um column (Agilent), was used. The temperature ramp was: 100 °C x 1 min, 15 °C/min up to 250 °C, 250 °C for 4 min. The sample solutions were prepared by accurately weighing about 0.40 g of conditioning agent in a 20 ml vial and adding 1.00 ml of internal standard solution, 0.10 ml of HC1 37% and 9.00 ml of ethyl ether. The solution was subjected to sonication for 45 min. 0.50 ml of the liquid phase were transferred in autosampler vial together with 0.20 ml of pyridine, 0.80 ml of derivatizing agent N,O-bis-(trimethylsilyl)-trifluoroacetamide, Apollo Scientific) and heated at 70 °C for 40 min. A 10.0 mg/ml solution of pentanoic acid in ethyl ether was used as internal standard solution.

The actual carboxymethyl and cationic degree of substitution (DSacM and DSa_cat, respectively) of the cationic CMT were calculated by mass balance between the reactive agents and the reaction by-products. The residual reactive agent content was considered negligible.

The DSa_cat of the cationic tamarind was determined by ¹ H-NMR according to the method described in WO 2024/156778.

The viscosity of the conditioning agents was determined with a Brookfield® RVT viscosimeter on 4.0 wt% solutions in water, at 20 rpm and 20 °C.

The ash content was determined by incineration in a muffled furnace at 650 °C. 1.00-2.00 g of conditioner (depending on the expected ash content) were weighed in a tared crucible. The crucible was then heated using a Bunsen burner until the production of smoke was negligible and transferred in a muffled furnace set at 650 °C for 10 hours. The crucible was finally weighed after cooling in a desiccator and the ash content was calculated.

The biodegradability of the conditioning agents of the Examples was determined according to the OECD 30 IF standard method. The following test conditions were used:

Test Substance: about 90 mg ThOD /I

Inoculum: activated sludge from domestic waste water treatment plant; 7 days of preconditioning in the mineral medium;

10⁷ - 10⁸/l;

<30 mg/1 SS;

Temperature: 22 ± 2

Duration: 28 days

Example 1

1000 g of a carboxymethylated tamarind gum (DS 0.21) were loaded in a 5 liters reactor at room temperature and the atmosphere was made inert by means of vacuum/nitrogen washings. A mixture of 166 g of water, 416 g of isopropyl alcohol and 125 g of a 30 wt% aqueous NaOH solution was added and homogenized for 15 minutes. The slurry was heated at 40°C and maintained at this temperature for 45 minutes. Subsequently, 133 g of a 65 wt% aqueous solution of (3-chloro-2- hydroxypropyl)trimethyl ammonium chloride (QU AB 188) were added and the mixture was heated to 50 °C for 2 hours (Step I).

At the end of Step I, other 175 g of the 30 wt% aqueous NaOH solution were added and the reaction mass was maintained at 50 °C for 2 additional hours (Step II).

The reaction mass was then cooled to 40 °C and the pH was adjusted to about 9- 11 with citric acid. The solvent was distilled off.

The conditioning agent so obtained was dried on a fluid bed drier using hot air until the moisture content was about 3% by weight and then milled.

Example 2

1000 g of de-oiled tamarind gum and 134 g of sodium chloroacetate were loaded in a 5 liters reactor at room temperature and the atmosphere was made inert by means of vacuum/nitrogen washings. A mixture of 60 g of water, 416 g of isopropyl alcohol and 278 g of a 30 wt% aqueous NaOH solution was added and stirred for 15 minutes. The slurry was heated at 40°C and maintained at this temperature for 45 minutes. Subsequently, 133 g of a 65 wt% aqueous solution of QU AB 188 were added and the mixture was heated to 50 °C for 2 hours (Step I). At the end of Step I, other 175 g of the 30 wt% aqueous NaOH solution were added and the reaction mass was maintained at 50 °C for 2 additional hours (Step II).

Example 3

Example 3 was prepared following the procedure of Example 2, using, in Step I, 33 g of sodium chloroacetate and a mixture of 140 g of water, 416 g of isopropyl alcohol and 163 g of a 30 wt% aqueous NaOH solution.

Example 4

Example 4 was prepared following the procedure of Example 2 using 67 g of sodium chloroacetate and a mixture of 113 g of water, 416 g of isopropyl alcohol and 201 g of a 30 wt% aqueous NaOH solution in Step I.

Example 5

Example 5 was prepared following the procedure of Example 2, using 67 g of sodium chloroacetate, a mixture of 113 g of water, 416 g of isopropyl alcohol and 233 g of a 30 wt% aqueous NaOH solution. Afterwards, 167 g of QU AB 188 were added.

Example 6

Example 6 was prepared following the procedure of Example 2 using 309 g of a 30 wt% aqueous NaOH solution and 167 g of QUAB 188 in Step I.

Example 7 (Comparative)

800 g of de-oiled tamarind gum were loaded in a 5 liters reactor at room temperature and the atmosphere was made inert by means of vacuum/nitrogen washings. A mixture of 133 g of water and 333 g of isopropyl alcohol was added and stirred for 10 minutes. Then 100 g of a 30 wt% aqueous NaOH solution were sprayed on the mixture, which was then homogenized for 30 minutes at 40°C. 107 g of a 65 wt% aqueous solution of QU AB 188 were added and the mixture was heated to 50°C for 2 hours (Step I).

Other 140 g of the 30 wt% aqueous NaOH solution were added and the basic treatment at 50 °C was continued for additional 2 hours (Step II).

The conditioning agent so obtained was dried on a fluid bed drier using hot air until the moisture content was about 5%by weight and then milled.

Example 8

1000 g of oiled tamarind gum and 133 g of sodium chloroacetate were loaded in a 5 liters reactor at room temperature and the atmosphere was made inert by means of vacuum/nitrogen washings. A mixture of 29 g of water, 417 g of isopropyl alcohol and 321 g of a 30 wt% aqueous NaOH solution was added and stirred for 15 minutes. The slurry was heated at 40 °C and maintained at this temperature for 45 minutes. Subsequently, 133 g of a 65 wt% aqueous solution of QU AB 188 were added and the mixture was heated to 50 °C for 2 hours (Step I).

Example 9

1000 g of oiled tamarind gum and 202 g of sodium chloroacetate were loaded in a 5 liters reactor at room temperature and the atmosphere was made inert by means of vacuum/nitrogen washings. A mixture of 416 g of isopropyl alcohol and 420 g of a 30 wt% aqueous NaOH solution was added and stirred for 15 minutes. The slurry was heated at 40 °C and maintained at this temperature for 1 hour.

The synthesis was completed following the procedure of Example 8. Example 10

Example 10 was prepared following the procedure of Example 8 using de-oiled tamarind gum.

Example 11

Example 11 was prepared following the procedure of Example 7 using 105 g of a 30 wt% aqueous NaOH solution and 135 g of QU AB 188 in Step I.

Example 12

800 g of deoiled tamarind gum were loaded In a 5 liters reactor at room temperature and the atmosphere was made inert by means of vacuum/nitrogen washings. A mixture of 160 g of water and 335 g of isopropyl alcohol was added and stirred for

10 minutes. Then 152 g of a 30 wt% aqueous NaOH solution were sprayed on the mixture, which was then homogenized for 30 minutes at 40°C. 194 g of a 65 wt% aqueous solution of QU AB 188 were added and the mixture was heated to 50°C for 2 hours (Step I).

Other 120 g of the 30 wt% aqueous NaOH solution were added and the basic treatment at 50 °C was continued for additional 90 minutes (Step II).

The reaction mass was then cooled to 40 °C and the pH was adjusted to about 9-

11 with citric acid. The solvent was distilled off.

The DScat and DSCM, the Brookfield RVT viscosity in mPa*s (VB) and the content of Ashes (wt%), CHPTAC (ppm), DHPTAC (wt%) andNaMCA (wt%) and of the conditioning agents of the Examples 1-7 12 are reported in Table 1 and 2.

Tables 1 and 2 also report the actual cationic and carboxymethyl degree of substitution (DSacM and DSa_cat, respectively).

The cationic CMT according to the invention advantageously show a very low amount of residual CHPTAC and NaMCA, even below the limit of detection of the analytical method. Table 1

Table 2

* Comparative

Biodegradability Tests

Table 2 reports the results obtained with the biodegradability tests conducted according to the standard method OECD 30 IF as % biodegradability at 28 days and as Ready Biodegradability (RB). Table 3

The results of the biodegradability test demonstrate that the conditioning agents of the invention, based a cationic CMT, are readily biodegradable and are much more biodegradable than commercial cationic guar.

APPLICATION TESTS

Stability Tests

Two shampoos were prepared, to assess the stability of cationic CMTs in comparison with cationic tamarinds.

The following ingredients were used:

CAPB = Cocamidopropyl Betaine, 30 wt% active matter in water;

SLES = Sodium Laureth Sulfate, 27 wt% active matter in water;

APG Tartrate = Sodium Coco-Glucoside Tartrate, 30 wt% active matter in water; Preservative = ACNIBIO AC (from ACEF S.p.A.);

The cationic CMT of Examples 1 and 8-9 and the cationic tamarind of Examples 7, 10 and 11 were used as conditioning agent.

The shampoos were prepared mixing the ingredients in the order as reported in Table 4. The conditioning agent was added into water at 50°C under vigorous stirring, and kept under stirring for about 30 min, in order to ensure the complete swelling of the polymer before adding the other ingredients. Table 4

The RVT Brookfield viscosity (at 20 rpm and 25 °C) in mPa*s of the shampoos are reported in Table 5 together with their stability, determined by storing the liquids for 3 months at 3 different temperatures, i.e. 5, 25 and 40 °C.

Table 5

* Comparative

The shampoos containing the conditioning agent of Examples 1, 8-9, according to the invention were stable, i.e. no changes in appearance, viscosity and pH were observed through the three months of the test, even in the presence of high amounts of an anionic surfactant. This applies to all temperatures.

On the contrary, the shampoos containing the conditioning agent of comparative Examples 7, 11 and 12 were unstable: flocculation of the cationic polysaccharide was observed after 7 days at 40 °C and after three weeks at 25 °C. Wet-Combing Tests

In order to evaluate the wet combing performances of the cationic CMTs, other shampoos were prepared using the cationic CMT of Examples 1 and 8-10, according to the invention.

TEGO® PEARL N300 (N300, from EVONIK) was used as further ingredient.

The recipe of the shampoo is reported in Table 6, in parts by weight.

Table 6

The shampoo was prepared mixing the ingredients in the order as reported in the Table 3. The conditioning agent was added into water at 50 °C under vigorous stirring and kept under stirring for about 20 min, in order to ensure the complete swelling of the polymer before adding the other ingredients.

A control shampoo (Control) was prepared using the same formula and procedure, without the addition of any conditioning agent.

For comparison, two shampoos containing a commercial cationic guar-based conditioning agent, or Polyquatemium-10, a widely-used conditioner based on cationic cellulose, were prepared.

The RVT Brookfield viscosity (at 20 rpm and 25 °C) in mPa*s of the shampoo are reported in Table 7 together with its stability, determined by storing the liquid for 3 months at 3 different temperatures, i.e. 5, 25 and 40 °C. Table 7

To determine the combing performance of the shampoo compositions, a Wet Combing Test was performed on regular bleached Caucasian hair switches (International Hair Importers & Products, Glendale NY). The average combing force values were determined with a DIA-STRON MTT 175 device (Miniature Tensile Tester).

The Combing Force Reduction (CFR%) was calculated according to the formula shown below:

ACFt - ACFu

CFR % x 100

ACFu where

ACFt = average combing force of the treated sample;

ACF_U= average combing force of the untreated sample.

The lower the value of the force, the higher the wet conditioning efficiency of the shampoo. Combing Force Reduction (CFR%) results for Example 1 are reported in Table 8.

The cationic CMT according to the invention show excellent conditioning effects, comparable to that of commercial conditioning agents based on cationic polysaccharides. Table 8

* Comparative

Claims

1) Conditioning agent comprising: a) from 47 to 88 % by weight of the chloride of 2-hydroxy-3- (trimethylammonium)propyl ether of carboxymethyl tamarind (cationic CMT) having a minimum DS_cat of 0.01 and a maximum DS_cat of 0.30 and a minimum DSCM of 0.01 and a maximum DSCM of 0.50; b) from 0.3 to 8.0 % by weight of (2,3-dihydroxypropyl)trimethyl ammonium chloride; c) from 5.0 to 33 % by weight of ashes determined at 650 °C; wherein the component b) is a by-product of the cationization reaction and the cationic CMT does not contain other substituents.

2) The conditioning agent of claim 1, wherein said cationic CMT has a minimum DS_cat of 0.01 and a maximum DS_cat of 0.25 and a minimum DSCM of 0.01 and a maximum DSCM of 0.30.

3) The conditioning agent of claim 1, comprising: a) from 47 to 88 % by weight, of cationic CMT having a minimum DS_cat of 0.01 and a maximum DS_cat of 0.15 and a minimum DSCM of 0.01 and a maximum DSCM of 0.25; b) from 0.3 to 7.0 % by weight of (2,3-dihydroxypropyl)trimethyl ammonium chloride; c) from 8.0 to 30 % by weight of ashes determined at 650 °C; wherein the component b) is a by-product of the cationization reaction and the cationic CMT does not contain other substituents.

4) The conditioning agent of claim 4, comprising: a) from 47 to 88 % by weight of cationic CMT having a minimum DS_cat of 0.01 and a maximum DS_cat of 0.10 and a minimum DSCM of 0.01 and a maximum DSCM of 0.25; b) from 0.3 to 5.0 % by weight of (2,3-dihydroxypropyl)trimethyl ammonium chloride; c) from 10.0 to 27 % by weight of ashes determined at 650 °C; wherein the component b) is a by-product of the cationization reaction and the cationic CMT does not contain other substituents.

5) The conditioning agent according to any of the preceding claims, further comprising from 0.05 to 5.0 % by weight of sodium glycolate.

6) Personal care and household care compositions comprising from 0.01 to 10 % by weight, based on the total weight of the compositions, of a conditioning agent according to any of the preceding claims.

7) The personal care and household care compositions of claim 6), comprising from 0.03 to 5.0 % by weight, based on the total weight of the compositions, of said conditioning agent.