Polymer taking the form of a pulverulent solid and having properties for thickening polar media

Abstract

Disclosed is a polymer (P) in the form of a pulverulent solid consisting of monomeric units derived from partially or totally solidified glutamic acid (GA), and monomer units of at least one crosslinking agent (AR) having at least two glycidyl functions.

Claims

1. A polymer (P) in the form of a pulverulent solid comprising monomer units derived from partially or totally salified glutamic acid (GA), and monomer units of at least one crosslinking agent (XLA) bearing at least two glycidyl functions.

2. The polymer (P) as claimed in claim 1, wherein the crosslinking agent (XLA) is chosen from the members of the group consisting of: monoethylene glycol diglycidyl ether of formula (I): ##STR00042## the compound of formula (II): ##STR00043## with R representing a hydrogen atom or the glycidyl radical ##STR00044## and n representing an integer greater than or equal to one and less than or equal to 10; 1,3-propanediol diglycidyl ether of formula (III): ##STR00045## 1,2-propanediol diglycidyl ether of formula (IV): ##STR00046## 1,4-butanediol diglycidyl ether of formula (V): ##STR00047## 1,2-butanediol diglycidyl ether of formula (VI): ##STR00048## 1,3-butanediol diglycidyl ether of formula (VII): ##STR00049## 1,6-hexanediol diglycidyl ether of formula (VIII): ##STR00050## the compound of formula (IX): ##STR00051## with R1 representing a hydrogen atom or the glycidyl radical ##STR00052## the compound of formula (X): ##STR00053## with R1 representing a hydrogen atom or the glycidyl radical ##STR00054## the compound of formula (XI): ##STR00055## with R1 and R2 which are independent and represent a hydrogen atom or the glycidyl radical ##STR00056## the compound of formula (XII): ##STR00057## with m representing an integer greater than or equal to 2, the compound of formula (XIII): ##STR00058## with R3 representing a hydrogen atom or the glycidyl radical ##STR00059## and x, y, z, o, p and q, independently of each other, representing an integer greater than or equal to 2 and less than or equal to 10.

3. The polymer (P) as defined in either of claim 1, wherein the polyglutamic acid (PGA) is -polyglutamic acid or PGGA.

4. The polymer (P) as claimed in claim 1, wherein, per 100% of the mass of monomer units derived from partially or totally salified glutamic acid (GA), the crosslinking agent (XLA) represents from 0.5% to 10% by mass.

5. The polymer (P) as claimed in claim 1, wherein said polymer also comprises a compound of formula (XIV): ##STR00060## with R4 representing a linear or branched, saturated or unsaturated hydrocarbon-based radical optionally including at least one hydroxyl function and including from 6 to 22 carbon atoms.

6. The polymer (P) as claimed in claim 5, wherein R4 represents a hydrocarbon-based radical chosen from the elements of the group consisting of heptyl, octyl, nonyl, decyl, undecyl, undecenyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, hydroxyoctadecyl, oleyl, linoleyl, linolenyl, eicosyl and dodecosyl radicals.

7. The polymer (P) as claimed in claim 5, wherein per 100% of the mass of monomer units derived from partially or totally salified glutamic acid (GA), the compound of formula (XIV) represents from 1% to 50% by mass.

8. A process for preparing a polymer (P) as defined in claim 1, comprising: a) a step of preparing a polar phase (PP) comprising partially or totally salified polyglutamic acid, at least one polar solvent (PS) and at least one crosslinking agent (XLA) comprising at least two glycidyl functions, b) a step of adjusting the pH of the aqueous solution obtained in step a) to a pH of between 3 and 11, c) a step of drying by spraying the polar phase (PP) resulting from step b) so as to obtain the polymer (P).

9. The process as claimed in claim 8, wherein in step a), the polyglutamic acid is PGGA.

10. The process as claimed in claim 9, wherein in step a), all of the monomer units constituting the polyglutamic acid (PGA) are derived from sodium glutamate, potassium glutamate, ammonium glutamate, calcium glutamate, magnesium glutamate or a mixture of these forms.

11. The process as claimed in claim 8, wherein in step a), the polar phase (PP) comprises, per 100% of its mass: from 5% to 70% by mass of polyglutamic acid, from 0.025% to 7% by mass of the crosslinking agent (XLA), from 23% to 94.975% by mass of at least one polar solvent.

12. The process as claimed in claim 8, wherein in step a), the polar solvent (PS) is chosen from the elements of the group consisting of water, methanol, ethanol, 1-propanol, 2-propanol, isobutanol, tert-butanol, 2-methyl-2-propanol, 1-butanol, 2-butanol, acetone, dimethyl ketone, diethyl ketone, tetrahydropyran, tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxane and 1,4-dioxane.

13. The process as claimed in claim 8, wherein in step a), the polar phase also comprises at least one compound of formula (XIV): ##STR00061## with R4 representing a linear or branched, saturated or unsaturated hydrocarbon-based radical optionally including at least one hydroxyl function and including from 6 to 22 carbon atoms.

14. The process as claimed in claim 13, wherein R4 represents a hydrocarbon-based radical chosen from the elements of the group consisting of heptyl, octyl, nonyl, decyl, undecyl, undecenyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, hydroxyoctadecyl, oleyl, linoleyl, linolenyl, eicosyl and dodecosyl radicals.

15. The process as claimed in claim 13, wherein the content of compound of formula (XIV) in the polar phase (PP) is, per 100% by mass of said polar phase (PP), between 0.05% and 35% by mass, it being understood that the sum of the mass proportions of the polyglutamic acid (PGA), of the crosslinking agent (XLA), of the polar solvent (PS) and of the compound of formula (XIV) is equal to 100%.

16. The process as claimed in claim 8, wherein step c) is performed with an atomizer using an air stream and a nozzle.

17. The process as claimed in claim 16, wherein the inlet temperature of the air stream is between 80 and 180 C. and preferably between 100 and 170 C.

18. A cosmetic composition for topical use (F) comprising, per 100% of its total mass, between 0.05% by mass and 10% by mass of at least one polymer (P) as defined in claim 1.

Description

EXAMPLES

[0146] The examples that follow illustrate the invention without, however, limiting it.

Example 1: Preparation of a Sodium PGGA According to the Invention Crosslinked with Polyethylene Glycol Diglycidyl Ether and Atomized

[0147] The synthetic process comprises the following four steps:

[0148] Step 1): Preparation of an Aqueous Sodium PGGA Gel:

[0149] 200 grams of demineralized water are stirred with a Rayneri brand mechanical stirrer equipped with a deflocculating-type rotor, and 20 grams of PGGA, sold by the company Lubon under the name Cosmetic Grade PGGA, are then slowly added into the vortex.

[0150] Step 2): pH Adjustment:

[0151] The pH of the mixture from step 1) is adjusted to a value of between 5.5 and 6.0 using aqueous 5M HCl solution (temperature=20 C.).

[0152] Step 3): Addition of the Crosslinking Agent:

[0153] 1.2 grams of polyethylene glycol diglycidyl ether (PEGDGE) with an average molecular weight of the order of 500 g/mol are added to the mixture of step 2).

[0154] Step 4): Atomization:

[0155] The aqueous solution obtained in step 3) is concentrated by passage through an atomizer whose operating parameters are as follows: [0156] Solution introduction rate=4 ml/min, [0157] Spraying nozzle pressure=1.5 bar, [0158] Circulating air temperature=150 C.,

[0159] Composition (E1) is finally isolated in the form of a pulverulent powder.

Example 2: Preparation of a Sodium PGGA According to the Invention Crosslinked with 1,4-Butanediol Diglycidyl Ether and Atomized

[0160] The synthetic process of Example 1 is reproduced, replacing the 1.2 grams of polyethylene glycol diglycidyl ether (PEGDGE) with 0.48 gram of 1,4-butanediol diglycidyl ether sold under the name Erisys GE 21 by the company Emerald.

[0161] The composition (E2) obtained is finally isolated in the form of a pulverulent powder.

Evaluation of the Crosslinked and Atomized Sodium PGGAs Obtained in the Two Preceding Examples:

[0162] The evaluation of compositions (E1) and (E2) (crosslinked and atomized sodium PGGAs), obtained in the two preceding examples was performed as follows: [0163] In a 400 ml high-sided beaker, dispersion of 4 grams of the compositions to be tested in 196 grams of water with stirring using a Rayneri brand mechanical stirrer equipped with a deflocculating-type rotor, until a homogeneous gel is obtained, [0164] Measurement of the dynamic viscosity using a Brookfield RVT viscometer, speed 5, choosing the appropriate spindle, [0165] Addition of 0.1% of NaCl to the gel obtained previously, stirring with a Rayneri brand mechanical stirrer equipped with a deflocculating-type rotor, until the mixture is homogeneous, [0166] Measurement of the dynamic viscosity using the same viscometer as previously, again choosing the appropriate spindle.

[0167] A control was produced from non-crosslinked PGGA sold by the company Lubon under the name Cosmetic Grade PGGA.

[0168] The measured dynamic viscosity values are collated in the table below:

TABLE-US-00001 TABLE 1 Viscosity in Viscosity in mPa .Math. s of mPa .Math. s of the gel Nature of the gel containing crosslinking containing 2% 2% polymer + Composition agent polymer 0.1% NaCl Control.sup.a) No 176 (spindle 2) 128 (spindle 2) Composition PEGDGE 30 400 (spindle 5) 9320 (spindle 3) (E1) Composition Erisys GE 21 41 520 (spindle 5) / (E2) .sup.a)Non-crosslinked PGGA sold by the company Lubon under the name Cosmetic Grade PGGA

[0169] Dynamic viscosities of aqueous gels obtained with compositions (E1) and (E2).

[0170] The control sodium PGGA gels (non-crosslinked and non-atomized) have viscosities of between 100 and 200 mPa.Math.s in the presence or absence of NaCl.

[0171] In the absence of NaCl, the crosslinked and atomized sodium PGGA gels have viscosities respectively equal to 30 400 mPa.Math.s in the case where the crosslinking agent is PEGDGE and 41 520 mPa.Math.s with Erisys GE 21 as crosslinking agent.

[0172] In the presence of NaCl, the viscosity of the sodium PGGA gel crosslinked with PEGDGE and atomized is equal to 9320 mPa.Math.s.

[0173] Compositions (E1) and (E2) according to the invention thus make it possible to thicken aqueous phases.