EP1008644A1 - Fluid concentrated hydroalcoholic compositions of copra or oil palm alkyl-amidopropylbetains - Google Patents

Abstract

Novel compositions (A) contain an alkylamidopropyl betaine (I) (based on hydrogenated copra or African palm oil fatty acid), salt, water and ethanol in specific ratios to provide stable, mobile, readily pumped, clear, almost colorless solutions. Novel compositions (A) comprise mobile, readily pumped, clear, almost colorless solutions, which are stable at 5-50 degrees C, have viscosity below 100 mPa.s and contain an alkylamidopropyl betaine of formula (I), salt (S), water (W) and ethanol (E). (A) contains: (i) 52-57% (I), at least 20% (W) and at least 21% (E) (where the (I) content is calculated as dry solids content minus sodium chloride content); (ii) at least 54% (W) based on (W) plus (E) and (iii) less than 6 wt. % (S). R = residue of a hydrogenated copra or African palm oil fatty acid cut residue of iodine index 1 or less. An Independent claim is included for the preparation of (A).

Description

   dans laquelle R représente le radical alkyle d'une coupe d'acides gras de type coprah ou palmiste hydrogénés, d'indice d'iode au maximum de 1 (en grammes d'iode par 100 g). La composition approximative d'une telle coupe est, en pourcents pondéraux :

50-65 % d'acide laurique,

15-26 % d'acide myristique,

8-14 % d'acide palmitique,

7-15 % d'acide stéarique,

la fraction insaturée responsable du faible indice d'iode étant représentée par moins de 1% d'acide oléique.The invention relates to concentrated hydroalcoholic solutions of low viscosity, clear, little colored and stable in a temperature range between 5 and 50 ° C, and containing at least 50% by weight of alkylamidopropylbetaine corresponding to the general formula (I) :

in which R represents the alkyl radical of a cut of hydrogenated coconut or palm kernel fatty acids, with an iodine index of maximum 1 (in grams of iodine per 100 g). The approximate composition of such a cut is, in weight percentages:

50-65% lauric acid,

15-26% myristic acid,

8-14% palmitic acid,

7-15% stearic acid,

the unsaturated fraction responsible for the low iodine value being represented by less than 1% of oleic acid.

In the rest of the presentation, we will simply call "betaines" these alkylamidopropyl betaines. Their solutions have these qualities only if their composition is chosen precisely in an area of the betaine diagram / ethanol / water normalized to 100 by weight after correction of the NaCl present.

Betaines corresponding to the general formula (I) are surfactants amphoteric very well tolerated by the skin, having excellent characteristics cleansers and foamers, and which are perfectly suited for making a multitude of surfactant compositions, such as washing agents, cleaning agents (liquid products for washing dishes by hand) and compositions for hair care (shampoo) and body care (shower gel and bubble bath).

par l'acide monochloracétique en présence d'un sel alcalin ou le sel correspondant de cet acide, la réaction de quaternisation s'opérant le plus souvent en milieu aqueux. Le chlorure alcalin, fréquemment le chlorure de sodium, sous-produit de la réaction, est généralement laissé dans cette solution aqueuse de bétaïne. Ces bétaïnes aqueuses sont commercialisées avec une concentration voisine de 30 % en poids.The preparation of this type of betaine is described in numerous documents, and the methods are known to those skilled in the art, for example US Pat. No. 3,225,074 (American Cyanamid). It consists in reacting a fatty acid or a cut of fatty acids with N, N-dimethyl-1,3-propanediamine (DMAPA) between 140 and 200 ° C, then quaternizing the tertiary amidoamine obtained, of general formula (II):

with monochloroacetic acid in the presence of an alkaline salt or the corresponding salt of this acid, the quaternization reaction most often taking place in an aqueous medium. The alkali chloride, frequently sodium chloride, a byproduct of the reaction, is generally left in this aqueous betaine solution. These aqueous betaines are sold with a concentration close to 30% by weight.

We have often tried to prepare betaine solutions industrially as concentrated and as fluid as possible, for understandable reasons reduction in transport and storage costs, without sacrifice ease of handling.

Those skilled in the art know that when the concentration of an aqueous solution of surfactant increases, its viscosity also increases. Some authors have nevertheless sought to concentrate solutions by evaporation under reduced pressure of betaine obtained according to the usual methods, but their viscosity increases rapidly, and they become pasty to about 40% by weight of betaine, then continue to solidify as the water leaves: it it is not possible to obtain concentrated solutions along this route. It is however reported in EP 0,302,329 (Th. Goldschmidt) that it was possible to partially overcome this difficulty by adjusting the pH of the solution between 1 and 4.5 with a mineral acid (hydrochloric, sulfuric, phosphoric). The authors thus obtain solutions containing from 43 to 44% by weight of betaine (or 53 54% dry extract) with a viscosity close to 1000 mPa.s at 25 ° C. But the corrosion problems during storage and transport as well as atypical pH of these betaine solutions limit their use, and moreover they gel in below 16 ° C.

Another way is that of obtaining betaine powder, by atomization fluid solutions less than 30%. We can think of redissolving these powders in suitable solvents, but the redissolution of these powders is hindered by formation when the powder and the solvent are brought into contact lumps or jellied pasta that can practically no longer iron solution, at least in reasonable time and compatible with an activity industrial.

International application WO 97/12856 (HENKEL) discloses and claims a process for manufacturing low-grade betaine surfactants in salts (0.98 to 1.01% residual NaCl) by quaternization of tertiary amines and / or tertiary amidoamines with sodium monochloroacetate in a hydroalcoholic mixture composed of 5 to 10% by weight of water and 35 to 50% by weight of ethanol and / or isopropanol, this reaction being followed by elimination of the precipitated salt fraction, total elimination of the solvent and readjustment in water from the reaction medium in order to bring the solution to the concentration of desired active ingredient, in this case 30%. The water / ethanol weight ratio claimed by the authors is typical of a process to remove NaCI formed during the reaction. A composition of this kind had been the subject of US Patent 4,705,893 (KAO), represented by a pentagonal area of the betaine / water / ethanol ternary diagram defined by triangular coordinates (80/10/10), (80/15/5), (40/55/5), 40 / 27.5 / 32.5) and (52.5 / 10 / 37.5). Within 2 case, these are processes whose main objective is to obtain solutions totally aqueous non-concentrated amphoteric surfactants with low contents in salts.

Those skilled in the art are familiar with the idea of the possible existence of fluid phase domains in an amphoteric / water / surfactant system solvent. This idea is taken up in WO 95/14076 (Albright and Wilson), in reality with no other concrete teaching than that of the individual examples reported in this publication which best approach the conditions of the problem present, namely coconut or lauryl-amidopropyl betaine - salt compositions solution in a mixed solvent of the water / glycol type.

The problem that remains is that of obtaining alkyl betaine solutions copra or hydrogenated palm kernel which are as concentrated as possible, that is to say at least 50% by weight, clear and little colored, fluid and pumpable (viscosity less than 1000 mPa.s), stable between 5 and 50 ° C on extended periods of time, in order to reduce packaging and transport costs and storage, which are easy to handle and can be formulated the state with other surfactants, for example alkyl ether sulfates, alkanolamides, or other basic raw materials used in particular in formulations liquid soaps, shampoos, shower gels, and other preparations cosmetics. The use of hydrogenated copra is a constraint imposed by the requirement for these compositions intended for cosmetic uses of a better oxidation stability than one would expect from natural cuts not hydrogenated.

The present invention provides a solution to this technical problem, which consists in preparing the alkyl betaine by quaternization of the reaction product of the dimethylaminopropylamine on a fatty acid from coconut or hydrogenated palm kernel in the presence of small amounts of ethanol, provided however that it is limited to one very precise and narrow domain of the phase diagram as defined now.

B* = [bétaïne / (bétaïne + eau + éthanol)] . 10²

W* = [eau / (bétaïne + eau + éthanol )] . 10²

E* = [éthanol / (bétaïne + eau + éthanol )] . 10²

où bétaïne a le sens de, et se mesure comme bétaïne = extrait sec - NaCI, où s'applique la relation de bouclage à 100% de la composition B* + W* + E* = 100,
toutes les grandeurs bétaïne, extrait sec, eau, éthanol, ClNa étant exprimées en poids, les grandeurs réduites B*, W* et E*, apparaissant comme des poids %. We reason in ternary compositions betaine / water / ethanol, represented on the ternary diagram in reduced coordinates

B * = [betaine / (betaine + water + ethanol)]. 10 ²

W * = [water / (betaine + water + ethanol)]. 10 ²

E * = [ethanol / (betaine + water + ethanol)]. 10 ²

where betaine has the meaning of, and is measured as betaine = dry extract - NaCI, where the looping relationship at 100% of the composition B * + W * + E * = 100 applies,
all the quantities betaine, dry extract, water, ethanol, ClNa being expressed by weight, the reduced quantities B *, W * and E *, appearing as weight%.

With this definition, the betaine taken into account is a crude betaine, that is to say made up of alkylamidobetaine such as corresponding to formula I, with some leftover reagents and some reaction byproducts exceeding not 3% by weight (see Example 1).

52 % ≤ B* ≤ 57 %

E* ≥ 21 %

W* ≥ 20 %

W* /W* + E* ≤ 54 %

The compositions of the invention are those which obey relationships

52% ≤ B * ≤ 57%

E * ≥ 21%

W * ≥ 20%

W * / W * + E * ≤ 54%

In the compositions of the invention, NaCI is present up to 6% maximum by weight, value beyond which these compositions become uncontrollable, if only by precipitation of salt.

The compositions according to the invention are suitable for prolonged storage on periods of at least three months, during which no gelation is observed, no demixing, no precipitation of salts, no significant change in color or clarity in the temperature range between 5 and 50 ° C. These solutions also have the advantage of being low foaming in the concentrated state, which facilitates their handling. Another advantage is that these solutions concentrates are sufficiently resistant to microbial invasion, so that the addition of preservatives is unnecessary. These characteristics make these solutions particularly suitable for making cosmetic compositions.

Another object of the present invention relates to the process for the manufacture of these concentrated solutions which consists in preparing the dimethylaminopropylamides of coconut or hydrogenated palm kernel intermediates and in quaternizing them with monochloroacetic acid in the presence of soda or sodium monochloroacetate directly in the chosen solvent medium, i.e. obeying the composition rule E * ≥ 21% W * ≤ 20% W * / W * + E * ≤ 54% defined above.

The following examples and counter-examples will make it easier to understand the invention.

Example 1 : Manufacture of a copra betaine hydrogenated to about 52.4% by weight of betaine, ie 57.4% of dry extract, the reduced coordinates B * / W * / E * in the phase diagram are 55 / 22.5 / 22 5 (in% by weight).

1 / a - Preparation of coconut aminoamide (Mw = 309 g)

Load 731 kg of coconut fatty acid with iodine number into a reactor ≤ 1, melted at 50 ° C. Purge the reactor and its contents by sparging with nitrogen and bring to 190 ° C. Add 347 kg of dimethylaminopropylamine in 4 hours (DMAPA), continuously removing the distillation water. Maintain at 190 ° C under nitrogen flow until the reaction product shows an index acid less than 4.5 mg KOH / g. Cool to 150 ° C, inject by dipping into 1 hour 100 kg of water and dry at 150 ° C with nitrogen bubbling to a water content less than 0.1%. Cool to 60 ° C, stop nitrogen sparging and drain.

The usual characteristics of the tertiary amidoamine thus obtained are the following: Alkalinity HClO4 3.28 - 3.32 IA 4.4 mg KOH / g Free fatty acid 1.6% DMAPA free 57 ppm Water content <0.1%

1 / b - Manufacture of the concentrated solution of coconut Betaine

In another reactor, load 233.7 kg of ethanol at room temperature, 127.4 kg of water, then 163 kg of monochloroacetic acid. Bring to 25 ° C, then slowly add 473 kg of the amidoamine prepared in 1 / a while controlling the exotherm so that the temperature does not exceed 40 ° C. Then add 153 kg of soda at 50% in about an hour, keeping the temperature at 40 ° C, then slowly rise to 80 ° C. Maintain at this temperature until the content in amidoamine reaches a stable value of 1%, ensuring that the pH of a test sample previously diluted to 5% in water is always between 10 - 10.5. After one hour, cool to 40 ° C and adjust the pH to 6.5 with a solution HCI 31%. Remove the NaCl fraction by decantation, filtration or centrifugation precipitate.

Monochloracétate de sodium < 3 ppm DMAPA libre < 5 ppm Glycolate de sodium 0,3 % Acide gras libre 0,8 % Amidoamine libre 1,0 % pH à 5 % (23°C) 6,5 Couleur Hazen (t = 0) 100 Hz Couleur Hazen (t = 6 semaines) 110 Hz A concentrated betaine solution is thus obtained having the following main compositions:

Sodium monochloroacetate <3 ppm DMAPA free <5 ppm Sodium glycolate 0.3% Free fatty acid 0.8% Amidoamine free 1.0% pH at 5% (23 ° C) 6.5 Hazen color (t = 0) 100 Hz Hazen color (t = 6 weeks) 110 Hz

It is a fluid solution, clear and easy to pump, stable between 5 and 50 ° C.

Counterexample 1 : The operating conditions of step 1 / b of Example 1 are repeated, with the exception of the raw material charges, which have been adjusted to obtain a betaine of copra hydrogenated at approximately 55.6% of betaine, ie 60.5% of dry extract, whose triangular coordinates B * / W * / E * corrected for NaCI in the phase diagram are 58.5 / 20.0 / 21 5 (in% by weight).

A viscous non-Newtonian birefringent gel, of crystal type, is obtained. liquid, difficult to handle and formulate between 5 and 50 ° C.

Counterexample 2 : The operating conditions of step 1 / b of Example 1 are repeated, with the exception of the raw material charges, which have been adjusted to obtain a copra betaine containing approximately 49.35% betaine. crude, ie 63.75% of dry extract, whose triangular coordinates B * / W * / E * corrected for NaCI in the phase diagram are 51.5 / 27.0 / 21.5 (in% by weight).

A fluid, clear and monophasic solution is obtained in the vicinity of the ambient temperature (20 - 25 ° C) but which, between 5 and 15 ° C, undergoes a change rapid towards a biphasic mixture with a viscous birefringent gel phase and a supernatant liquid phase. This heterogeneous product is difficult to use in the state.

Counterexample 3 : The same operating conditions are repeated as in step 1 / b of Example 1 with the exception of the raw material charges, which have been adjusted to obtain a copra betaine at approximately 53.95% of betaine, i.e. 58.75% solids, whose triangular coordinates B * / W * / E * corrected for NaCI in the phase diagram are 65.5 / 17.75 / 25.75 (in% by weight).

A solution is obtained which becomes heterogeneous on storage at 5 ° C.

Claims (2)

Compositions comprising an alkylamidopropyl betaine corresponding to the general formula (I):

salt, water and ethanol, in the form of fluid solutions, easy to pump, clear and little colored, stable between 5 and 50 ° C and having a viscosity of less than 1000 mPa.s, the radical alkyl R of said alkylamidopropyl betaine being that of a cut of fatty acid of the copra or hydrogenated palm kernel type, with an iodine index at most equal to 1,
characterized in that the components betaine, water and ethanol, reported in compositions reduced by B * = [betaine / (betaine + water + ethanol)]. 10 ² W * = [water / (betaine + water + ethanol)]. 10 ² E * = [ethanol / (betaine + water + ethanol)]. 10 ² where betaine has the meaning of, and is measured as betaine = dry extract - NaCI, are linked by relationships 52% ≤ B * ≤ 57% E * ≥ 21% W * ≥ 20% W * / W * + E * ≤ 54% which define their field of existence of the compositions as long as their salt content is less than 6% by weight. Process for obtaining the compositions as described in claim 1, which consists in preparing dimethylaminopropylamides of coconut or hydrogenated palm kernel intermediates and in quaternizing them with monochloroacetic acid in the presence of soda or with sodium monochloroacetate directly in the solvent water / ethanol compound medium so that we have E * ≥ 21% W * ≥ 20% W * / W * + E * ≤ 54% the reduced compositions E * and W * having the meanings given in claim 1.