EP4654943A1

EP4654943A1 - Conditioning agent

Info

Publication number: EP4654943A1
Application number: EP24702687.5A
Authority: EP
Inventors: Barbara Biasotti; Rossana COLOMBO; Valentina Langella; Stefano Monti
Original assignee: Lamberti SpA
Current assignee: Lamberti SpA
Priority date: 2023-01-27
Filing date: 2024-01-25
Publication date: 2025-12-03
Also published as: IT202300001335A1; CN120603574A; WO2024156778A1

Abstract

The present invention relates to a biodegradable conditioning agent comprising from 60 to 90 % by weight a cationic tamarind having a maximum DScat of 0.27, particularly having a minimum DScat of 0.02 or 0.06 and a maximum DScat of 0.27, from 1.0 to 8.0 % by weight of (2,3-dihydroxypropyl)trimethyl ammonium chloride and from 2.0 to 17.0 % by weight of ashes and to personal care and household care compositions containing said conditioning agent.

Description

CONDITIONING AGENT

FIELD OF THE INVENTION

The present invention relates to a biodegradable conditioning agent comprising from 60 to 90 % by weight of a cationic tamarind having a maximum DS_cat of 0.27, particularly having a minimum DS_cat of 0.02 and a maximum DScat of 0.27 and containing from 1.0 to 8.0 % by weight of (2,3-dihydroxypropyl)trimethyl ammonium chloride and from 2.0 to 17.0 % by weight of ashes, and to personal care and household care compositions containing said conditioning agent. The present invention also relates to a biodegradable conditioning agent comprising from 60 to 90 % by weight a cationic tamarind having a minimum DScat of 0.06 and a maximum DScat of 0.27, from 1.0 to 8.0 % by weight of (2,3-dihydroxypropyl)trimethyl ammonium chloride and from 2.0 to 17.0 % by weight of ashes, and to personal care and household care compositions containing said conditioning agent.

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 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 or (3-chloro-2-hydroxypropyl)trimethyl ammonium chloride, 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, preferably with high degree of cationic substitution, that comprise 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 conditioners and rheologys modifier obtained from the process of WO 2014/027120 by washing with water or solvents, as they contain less than 0.15 % by weight, preferably less than 0.01 % 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. 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 low biodegradability or not ready- biodegradable and there is a general trend for the industry to switch to other conditioning agents.

WO 2014/027120 is silent about 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 the synthesis and of reducing the production costs. Notto mention the difficulties in managing a lot of waste water and/or recycling the solvents.

Now, the Applicant has surprisingly found that conditioning agent based on cationic tamarinds obtained with the process of WO 2014/027120 and having a specific degree of substitution in the low or very low range are more biodegradable than the cationic galactomannans obtained with same process and the corresponding purified galactomannans. At the same time, they show excellent conditioning performances and a rheological behaviour similar to those of the cationic polysaccharides of the prior art. In the present text, with the expression, "cationic tamarind" we mean the chloride of the 2-hydroxy-3-(trimethylammonium)propyl ether of tamarind gum, (which are also known as the chloride of the 2-hydroxy-3-(trimethylammonium)propyl ether of tamarind gum). 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 means of ¹H-NM R.

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 (ThOD ) after 28 days (D28) of the conditioning agent of the invention is above 50 % according to the standard method OECD 301F.

The term "readily biodegradable" according to the standard method OECD 301 F means that the product reach 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 60 to 90 % by weight, preferably from 70 to 85 % by weight, of a cationic tamarind having a minimum DS_cat of 0.02 and a maximum DS_cat of 0.27, or a minimum DS_catof 0.06 and a maximum DS_cat of 0.27; b) from 1.0 to 8.0 % by weight, preferably from 1.2 to 5.0 % by weight, of (2,3- dihydroxypropyljtrimethyl ammonium chloride; and c) from 2.0 to 17.0 % by weight of ashes determined at 650 °C; wherein the component b) is a by-product of the cationization reaction and the cationic tamarind does not contain other substituents and wherein the % biodegradation after 28 days of said conditioning agent is above 50 % according to the standard method OECD 301F.

It is another object of the present invention 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.

It is a further object of the present invention the use of said conditioning agent as biodegradable ingredient of personal care and household care compositions.

DETAILED DESCRIPTION OF THE INVENTION

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

Briefly, the process can comprise the following steps: I) 100 parts by weight of tamarind gum are reacted with from 1 to 100 parts by weight of (3-chloro-2- hydroxypropyljtrimethyl ammonium chloride or of (2,3-epoxypropyl) trimethyl ammonium chloride and with from 0.4 to 50 parts by weight of sodium hydroxide (or equivalent amount of another alkaline hydroxide) in from 5 to 500 parts of water or of a water/alcohol mixture containing from 20 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 mixture 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 mixture 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 3 to 60 parts by weight of (3-chloro-2-hydroxypropyl)trimethyl ammonium chloride and from 1.0 to 20 parts by weight of sodium hydroxide are added.

According to another preferred embodiment of the present invention, in step I) of the process, from 5 to 60 parts by weight of (3-chloro-2-hydroxypropyl)trimethyl ammonium chloride and from 1.0 to 20 parts by weight of sodium hydroxide are added. The alcohol useful for the procedure of the invention is preferably ethanol, isopropanol, or mixtures thereof.

Preferably, in step I) of the process of the invention, from 15 to 150 parts by weight of water or of water/alcohol mixture each 100 parts by weight tamarind are used.

In another embodiment, in step I) of the process of the invention, from 50 to 150 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 and the cationizing agent are reacted for about 1 to 4 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 pre-mixed with the water or with the water/alcohol mixture and stirred for about 15 to 45 minutes; subsequently, the cationizing agent is added and reacted at about 40 to 70 °C for about 1 to 3 hours, before step II) takes place.

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 (1-4)-p-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 a-D-(1-6) linkage. One galactose unit is attached to one of the xylose units through p-D-(1-2) 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.

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 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 0.1 to 20 parts by weight, of sodium hydroxide (or equivalent amount of other alkaline hydroxide) each 100 parts of tamarind gum are added in step II).

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, gluconic 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 tamarind 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. The depolymerized cationic tamarind used in this invention is preferably prepared by treatment with alkali.

In a preferred embodiment, the depolymerized cationic tamarind 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 galactomannan, contains all the by-products deriving from the cationization reaction, e.g. (2,3-dihydroxypropyl)trimethyl ammonium chloride and inorganic and/or organic salts.

According to the invention, the cationic tamarind contains only cationic substituents. The cationic tamarind has a maximum DS_cat of 0.27, particularly has a minimum DS_cat of 0.02 and a maximum DS_cat of 0.27.

In a preferred embodiment, the cationic tamarind of the invention has a minimum DS_cat of 0.06, preferably of 0.08, more preferably of 0.09, and a maximum DS_cat of 0.27, preferably of 0.20, more preferably of 0.16, most preferably of 0.12. Any range of DS_cat 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 tamarind of the invention has a minimum DS_cat of 0.06 and a maximum DS_cat of 0.20.

In another embodiment, the cationic tamarind of the invention has a minimum DScat of 0.02 and a maximum DS_cat of 0.20, preferably of 0.16.

In yet another preferred embodiment, the cationic tamarind of the invention has a minimum DS_cat of 0.02, preferably of 0.03, and a maximum DS_cat below 0.06, preferably of 0.05.

At the end of the preparation procedure, the conditioning agent of the invention contains from 60 to 90 % by weight, preferably from 70 to 85 % by weight, of the cationic tamarind.

The conditioning agent has an ash content, related to the content of inorganic substances in the conditioning agent, from 2.0 to 17.0 % by weight (determined at 650 °C), preferably from 4.0 to 15.0 % by weight. The conditioning agent further contains from 1.0 to 8.0 % by weight, preferably from 1.0 to 5.0, or from 1.2 to 5.0 % by weight, even from 1.2 to 3.0 % by weight of (2,3- dihydroxypropyl)trimethyl ammonium chloride, formed from the reaction of (3-chloro- 2-hydroxypropyl)trimethyl ammonium chloride or of (2,3-epoxypropyl) trimethyl ammonium chloride, that is itself a cosmetic ingredient known with the INCI name of Dihydroxypropyl Trimonium Chloride.

The conditioning agent may further contain some residual water, normally between 2.0 and 12.0 % by weight, preferably between 3.0 and 8.0 % by weight.

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 and even more preferably below 30 ppm.

The conditioning agent according to present invention shows a % biodegradation after 28 days above 50 %, preferably above 60 %, more preferably above 70 %, according to the standard method OECD 301 F.

It has been found that the cationic tamarind of the invention having a minimum DS_cat of 0.02 and a maximum DS_cat below 0.06 shows a % biodegradation after 28 days above 75 %, according to the standard method OECD 301F 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 compositions, especially in hair care or skin care compositions.

In a particularly preferred embodiment of the invention, the conditioning agent comprises: a) from 60 to 90 % by weight, preferably from 70 to 85 % by weight, of a cationic tamarind having a minimum DS_cat of 0.02 and a maximum DS_cat below 0.06, preferably a minimum DS_catof 0.03 and a maximum DS_cat of 0.05; b) from 1.2 to 5.0 % by weight, preferably from 1.2 to 3.0 % by weight, of (2,3- dihydroxypropyl)trimethyl ammonium chloride; and c) from 8.5 to 13.0 %, preferably from 9.0 to 12.5 % by weight, by weight of ashes determined at 650 °C; wherein the component b) is a by-product of the cationization reaction and the cationic tamarind does not contain other substituents and wherein said conditioning agent is "readily biodegradable" according to the standard method OECD 301F.

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 tamarind 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 of the invention is also devoid of glyoxal, boron, or other crosslinking agents.

The conditioning agent of the invention can be used, as biodegradable ingredient, for the preparation of personal care and household care compositions for its viscosityenhancing, stabilizing and conditioning properties. It 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 skincleansing compositions, shampoos, 2-i n-1 shampoos, body and shower gels, bath foams, cleansing soaps and bars, cleansing powders and concentrates, make-up 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 alpha-hydroxy, 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 andinsect 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.

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 mono-alcohols 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. A ICS 5000 DC ion chromatograph (Thermo Scientific), equipped with a conductimetric detector, an lonPac CG-12A, 50 x 4.0 mm pre-column and a 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 (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, 1.7um, 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/H2O 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.

DScat was determined by ¹H-NMR analysis using a JEOL ECZ400R/S3 NM R spectrometer equipped with a RO5MAT Royal Digital Autotune Probe 5 mm i.d. Before the analysis, the conditioning agents were purified by precipitation with acetone from a water solution and subsequent washings with acetone. 50 mg of purified products were then hydrolyzed with DCI for 1 hour in boiling water to obtain a solution suitable for the NM R analysis. The signals of the non-anomeric protons (sugar ring protons) and those of the -CH3 protons of the cationic substituent were used for the DS_cat calculations. The viscosity of the conditioning agents was determined with a Brookfield® RVT viscosimeter on 4.0 wt% and 1.0 wt% solutions in water, for tamarind and guar respectively, at 20 rpm and 20 °C.

The ash content was determined by incineration in a muffled furnace at 650 °C.

The biodegradability of the conditioning agents of the Examples was determined according to the OECD 301 F 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 - 10® /I;

<30 mg/l SS;

Temperature: 22 ± 2

Duration: 28 days

Example 1

In a 5 liters reactor, 800 g of deoiled tamarind gum were loaded at room temperature and the atmosphere was made inert by means of vacuum/nitrogen washings. A mixture of 195 g of water and 335 g of isopropyl alcohol was added and stirred for 10 minutes. Then 150g of a 30 wt% aqueous NaOH solution were sprayed on the mixture, which was then homogenized for 15 minutes. 222 g of an 65 wt% aqueous solution of (3-chloro-2- hydroxypropyl)trimethyl ammonium chloride (QUAB 188) were added and the mixture was heated to 50°C for 2 hours (Step I). Other 100g of the 30 wt% aqueous NaOH solution were added and the basic treatment at 50 °C was continued for additional 2 hours (Step 11). 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

In a 5 liters stirred reactor, 800 g of guar powder were loaded at room temperature and the atmosphere was made inert by means of vacuum/nitrogen washings. 520 g of 1/2 water/isopropanol solution was added under vigorous stirring. After being stirred for 10 minutes, 201 g of an aqueous 30 wt% NaOH solution and 2.7 g of borax were added and stirred for additional 15 minutes. 280 g of QUAB 188 were added to the mixture, and the mixture was heated to 50°C for 2 hours.

The product was purified by washing with water. Thus, 200 g of reaction mixture were dispersed in 1400 g of water left under stirring for few minutes, then filtered under vacuum on a fabric filter. The cationic guar on the filter was further washed with 300 g of water.

The comparative purified cationic guar 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 3

Example 3 was prepared following the procedure of Example 1 using guar, as substrate.

Example 4

Example 4 was prepared using, as substrate, a deoiled tamarind gum which was treated with 3 g of hydrogen peroxide (130 vol), diluted in 45 g of deionized water, at 40 °C. The mass was then heated to 60 °C for 60 min in order to remove the residual hydrogen peroxide. The depolymerized tamarind gum was cationized following the procedure of Example 1.

Example 5

Example 5 was prepared following the procedure of Example 1 using guar, as substrate, but adding 155 g of QUAB 188 and 107 g of 30 wt% aqueous NaOH solution during the cationization.

Example 6

Example 6 was prepared following the procedure of Example 1, using 121 g of QUAB 188 and 84 g of 30 wt% aqueous NaOH solution in Step I.

Examples 7

In a 5 liters reactor, 800 g of deoiled tamarind gum were loaded 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 213 g of a 30 wt% aqueous NaOH solution were sprayed on the mixture, which was then homogenized for 30 minutes at 40°C. 155 g of a 65 wt% aqueous solution of QUAB 188 were added and the mixture was heated to 50°C for 2 hours. 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. 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 5%by weight and then milled.

Example 8

Example 8 was prepared following the procedure of Example 7, using 160g of isopropyl alcohol, 123 g of QUAB 188 and 97 g of 30 wt% aqueous NaOH solution in Step I.

Example 9

The preparation of Example 8 was repeated, using 160 g of 30 wt% aqueous NaOH solution in Step II.

Example 10

Example 10 was prepared following the procedure of Example 7, using 77 g of QUAB 188 and 106 g of 30 wt% aqueous NaOH solution in Step I.

Example 11

Example 11 was prepared following the procedure of Example 7, using 107 g of QUAB 188 and 100 g of the 30 wt% aqueous NaOH solution in Step I.

The DScat, the Brookfield RVT viscosity in mPa*s (VB) and the content of CHPTAC (ppm), DHPTAC (wt%) and Ashes (wt%) of the conditioning agents of the Examples 1-11 are reported in Table 1.

Table 1 also report the % biodegradation and the "ready biodegradability" (RB) of the conditioning agents of Examples 1-11.

Table 1

Comparative; ** Not Determined

The results of the biodegradability test demonstrate that the conditioning agents of the invention, based on a cationic tamarind, are more biodegradable than conditioning agents based on cationic galactomannans obtained with the same procedure and also than conditioning agents based on purified cationic galactomannans.

Moreover, the results of Examples 8 and 10 demonstrates that the cationic tamarinds having a DS below 0.06 are even "readily biodegradable", which allows to remarkably reduce the environmental footprint of the cosmetic compositions according to the invention.

Application Tests

The following ingredients were used:

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

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

N300 = TEGO® PEARL N300 (from EVONIK)

Preservative = AGNI BIO AC (from ACEF S.p.A.) Three shampoos were prepared using the cationic tamarind of Examples 4 and 8 and the comparative purified guar of Example 1. The recipe of the shampoos is reported in Table

2, in parts by weight.

Table 2

The shampoos were prepared mixing the ingredients in the order as reported in the Table 2. The conditioning agent was added into water under vigorous stirring, then pH was adjusted to 5.0-5.5 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.

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

Table 3

Comparative

The cationic Tamarinds of Example 1 and 6 show suitable viscosities and good stability similar to those of the cationic guar of the prior art, despite their low degree of substitution.

Wet-Combing Test

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;

ACFu = 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 are reported in Table 4. Table 4

Comparative

The cationic tamarinds of Examples 1, 6, and, in particular, of Examples 9 and 11 show an excellent conditioning effect, comparable to that of the purified comparative conditioning agent of Example 2.

Claims

1) Conditioning agent comprising: a) from 60 to 90 % by weight of a cationic tamarind having a minimum cationic degree of substitution (DS_cat) of 0.02 and a maximum DS_cat of 0.27; b) from 1.0 to 8.0 % by weight of (2,3-dihydroxypropyl)trimethyl ammonium chloride; and c) from 2.0 to 17.0 % by weight of ashes determined at 650 °C; wherein the component b) is a by-product of the cationization reaction and the cationic tamarind does not contain other substituents and wherein the % biodegradation after 28 days of said conditioning agent is above 50 % according to the standard method OECD 301F.

2) The conditioning agent of claim 1, comprising: a) from 60 to 90 % by weight of a cationic tamarind having a minimum DS_cat of 0.06 and a maximum DS_cat of 0.27; b) from 1.0 to 8.0 % by weight of (2,3-dihydroxypropyl)trimethyl ammonium chloride; and c) from 2.0 to 17.0 % by weight of ashes determined at 650 °C; wherein the component b) is a by-product of the cationization reaction and the cationic tamarind does not contain other substituents and wherein the % biodegradation after 28 days of said conditioning agent is above 50 % according to the standard method OECD 301F.

3) The conditioning agent of claim 1 or 2, wherein said cationic tamarind has a minimum DS_cat of 0.06 and a maximum DS_cat of 0.20.

4) The conditioning agent of claim 1 or 2, wherein the % biodegradation after 28 days of said conditioning agent is above 60 % according to the OECD 301F standard method.

5) The conditioning agent of claim 1, comprising: a) from 60 to 90 % by weight of a cationic tamarind having a minimum DS_cat of 0.02 and a maximum DS_cat below 0.06; b) from 1.2 to 5.0 % by weight, of (2,3-dihydroxypropyl)trimethyl ammonium chloride; and c) from 8.5 to 13.0 %, by weight of ashes determined at 650 °C; wherein the component b) is a by-product of the cationization reaction and the cationic tamarind does not contain other substituents and wherein said conditioning agent is "readily biodegradable" according to the standard method OECD 301F.

6) The conditioning agent of claims 1 or 2 or 5, wherein said conditioning agent has a residual content of (3-chloro-2-hydroxypropyl)trimethyl ammonium chloride or (2,3-epoxypropyl) trimethyl ammonium chloride below 200 ppm.

7) 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 claim 1 or 2 or 5.

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

9) Use of a conditioning agent according to claim 1 or 2 or 5 as biodegradable ingredient of personal care and household care compositions