OILY DISPERSION COMPRISING A POLYMERIC PARTICLE AND A STABILIZER BEARING A C9-C22 ALKYL GROUP, AND PROCESS FOR TREATING KERATIN MATERIALS USING THE OILY DISPERSION

Abstract

The present invention relates to an oily dispersion (A) comprising i) at least one particle consisting of an ethylenic polymer, ii) at least one polymeric stabilizer comprising a (C.sub.9-C.sub.22)alkyl group, and iii) at least one hydrocarbon-based fatty substance which is liquid at 20° C. and 1 atmosphere. The invention also relates to a process for treating keratin materials, notably human keratin materials such as the skin or the hair, involving the application to said materials of at least one oily dispersion (A); to a process for preparing the oily dispersion, and to a multi-compartment kit comprising ingredients i) to iii).

The oily dispersion (A) and the process for treating keratin materials as defined above make it possible to obtain a treatment for said materials which is notably resistant to shampoo washing, to sebum, to sweat and/or to water, but also to fatty substances, notably dietary fatty substances such as oils.

Claims

1. An oily dispersion comprising: i) one or more particles including one or more polymers chosen from: a) ethylenic homopolymers of (C.sub.1-C.sub.4)alkyl (C.sub.1-C.sub.4)(alkyl)acrylate; b) ethylenic copolymers of b1) (C.sub.1-C.sub.4)alkyl (C.sub.1-C.sub.4)(alkyl)acrylate, and of b2) ethylenic monomers comprising one or more carboxyl, anhydride, phosphoric acid, sulfonic acid and/or aryl groups; c) ethylenic homopolymers of (C.sub.1-C.sub.4)alkyl (C.sub.1-C.sub.4)(alkyl)acrylate, preferably (C.sub.1-C.sub.4)alkyl (meth)acrylate; and ii) one or more polymeric stabilizers chosen from: d) ethylenic homopolymers of (C.sub.9-C.sub.22)alkyl (C.sub.1-C.sub.6)(alkyl)acrylate, preferably (C.sub.9-C.sub.22)alkyl (meth)acrylate ethylenic homopolymers; and e) ethylenic copolymers of (C.sub.9-C.sub.22)alkyl (C.sub.1-C.sub.6)(alkyl)acrylate and of (C.sub.1-C.sub.4)alkyl (C.sub.1-C.sub.4)(alkyl)acrylate, preferably copolymers of (C.sub.9-C.sub.22)alkyl (meth)acrylate and of (C.sub.1-C.sub.4)alkyl (meth)acrylate; iii) one or more hydrocarbon-based liquid fatty substances; and iv) optionally one or more cosmetic active agents chosen from f) dyes, g) pigments; h) active agents for caring for keratin materials, notably the skin, and j) UV (A) and/or (B) screening agents, and m) mixtures thereof.

2. The oily dispersion according to claim 1, in which the particles i) consist of an ethylenic polymeric core obtained from homopolymers a) or from copolymers b) or c) and ii) of one or more polymeric surface stabilizers obtained from homopolymer d) and the copolymers e).

3. The oily dispersion according to claim 1, in which the polymer(s) constituting the particles i) are chosen from acrylate ethylenic homopolymers c) resulting from the polymerization of an identical monomer of formula (I):
H.sub.2C═C(R)—C(O)—O—R′  (I) in which formula (I): R represents a hydrogen atom or a (C.sub.1-C.sub.4)alkyl group, and R′ represents a (C.sub.1-C.sub.4)alkyl group.

4. The oily dispersion according to claim 1, in which the polymer(s) constituting the particles i) are chosen from acrylate ethylenic copolymers b) resulting from the polymerization: of at least two different monomers of formula (I):
H.sub.2C═C(R)—C(O)—O—R′  (I) in which formula (I): R represents a hydrogen atom or a (C.sub.1-C.sub.4)alkyl group, and R′ represents a (C.sub.1-C.sub.4)alkyl group; and optionally of a monomer of formula (II) H.sub.2C═C(R)—C(O)—O—H wherein R represents a hydrogen atom or a (C.sub.1-C.sub.4)alkyl group.

5. The oily dispersion according to claim 1, in which the monomers are chosen from C.sub.1-C.sub.4 alkyl (meth)acrylates.

6. The oily dispersion according to claim 1, in which the oily dispersion includes from 60% to 98% by weight of monomers a) to c) relative to the total weight of polymers contained in said dispersion.

7. The oily dispersion according to claim 1, in which the stabilizer(s) ii) are chosen from d) ethylenic homopolymers of (C.sub.9-C.sub.22)alkyl (C.sub.1-C.sub.6)(alkyl)acrylate.

8. The oily dispersion according to claim 1, in which the stabilizer(s) ii) are chosen from isodecyl, lauryl, stearyl, hexadecyl or behenyl (meth)acrylate homopolymer and statistical copolymers of isodecyl, lauryl, stearyl, hexadecyl or behenyl (meth)acrylate and of C.sub.1-C.sub.4 alkyl (meth)acrylate.

9. The oily dispersion according to claim 1, in which the stabilizer(s) ii) are chosen from e) ethylenic copolymers of (C.sub.9-C.sub.22)alkyl (C.sub.1-C.sub.6)(alkyl)acrylate and of (C.sub.1-C.sub.4)alkyl (C.sub.1-C.sub.4)(alkyl)acrylate.

10. The oily dispersion according to claim 1, in which the stabilizers(s) ii) are chosen from ethylenic copolymers e) resulting from the polymerization of a monomer of formula (IV) and of two different monomers of formula (III)
H.sub.2C═C(R)—C(O)—O—R′  (III) and
H.sub.2C═C(R)—C(O)—O—R″  (IV) in which formulae (III) and (IV): R, which may be identical or different, represent a hydrogen atom or a (C.sub.1-C.sub.4)alkyl group, R′, which may be identical or different, represent a (C.sub.1-C.sub.4)alkyl group and R″ represents a (C.sub.9-C.sub.22)alkyl.

11. The oily dispersion according to claim 10, in which the stabilizers(s) ii) are chosen from from copolymers resulting from the polymerization of two different monomers chosen from isodecyl, lauryl, stearyl, hexadecyl or behenyl (meth)acrylates and of one C.sub.1-C.sub.4 alkyl (meth)acrylate monomer.

12. The oily dispersion according to claim 1, in which the oily dispersion includes from 2% to 40% by weight of (C.sub.9-C.sub.22)alkyl (C.sub.1-C.sub.6)(alkyl)acrylate monomers included in d) or e) with the hydrocarbon-based liquid(s) iii), relative to the total weight of polymers contained in said dispersion.

13. The oily dispersion according to claim 1, in which the weight ratio of ii) the stabilizer(s) and i) of the polymer particle(s) present in the dispersion (A) is between 0.5 and 2.

14. The oily dispersion according to claim 1, in which the ii) stabilizer(s)+ii) polymer particle(s) assembly present in the dispersion (A) comprises from 2% to 40% by weight relative to the total weight of the dispersion.

15. The oily dispersion according to claim 1, in which the liquid hydrocarbon-based fatty substance(s) iii) are chosen from hydrocarbons, oils of animal origin, oils of plant origin, glycerides or fluorinated oils of synthetic origin, fatty alcohols, esters of fatty acids and/or of fatty alcohols, non-silicone waxes, and silicones.

16. The oily dispersion according to claim 1, in which the liquid hydrocarbon-based fatty substance(s) iii) are chosen from: plant oils formed by fatty acid esters of polyols; linear, branched or cyclic esters containing more than 6 carbon atoms; hydrocarbons; ethers containing 6 to 30 carbon atoms; ketones containing 6 to 30 carbon atoms; aliphatic fatty monoalcohols containing 6 to 30 carbon atoms, the hydrocarbon-based chain not including any substitution groups; polyols containing 6 to 30 carbon atoms; and mixtures thereof.

17. The oily dispersion according to claim 1, in which the liquid hydrocarbon-based fatty substance(s) iii) are present in the dispersion in a content ranging from 60% to 100% by weight relative to the total weight of the liquid hydrocarbon-based fatty substances present in the dispersion and from 0 to 40% by weight of silicone oil.

18. The oily dispersion according to claim 1, in which the cosmetic active agent(s) iv) are chosen from f) dyes.

19. The oily dispersion according to claim 1, in which the cosmetic active agent(s) iv) are chosen from: organic pigments and mineral or inorganic pigments.

20. A process for treating keratin materials comprising the application to said materials of the oily dispersion as defined in claim 1 and after application of the dispersion to the keratin materials, the composition being left to dry on said keratin materials either naturally or with the aid of heating devices used in cosmetics.

21. A kit or device with several separate compartments comprising the oily dispersion as defined in claim 1, and wherein the kit or device comprises: in one compartment: the ingredients i) to iii), and divided among one or more different compartments, the following ingredients: f) dyes, g) pigments; h) active agents for caring for keratin materials and j) UV (A) and/or (B) screening agents.

22. A process for preparing the oily dispersion as defined in claim 1, comprising the following steps: in a first step, the stabilizer ii) is prepared by mixing the constituent monomer(s) of the stabilizing polymer d) or e) with v) a free-radical initiator, in a solvent, and by polymerizing these monomers; in a second step, the constituent monomers of the polymer of the particles i) are added to the stabilizer formed in the preceding step and polymerization of these added monomers is performed in the presence of the free-radical initiator; it being understood that: when the non-aqueous medium is a non-volatile liquid hydrocarbon-based fatty substance iii), the polymerization may be performed in an apolar organic solvent and the non-volatile liquid hydrocarbon-based fatty substance is then added and the synthesis solvent may be selectively distilled off; when the non-aqueous medium is a volatile liquid hydrocarbon-based fatty substance iii), the polymerization may be performed directly in said oil, which also acts as synthesis solvent; the chosen cosmetic active agent(s) iv) may be added during the first step or the cosmetic active agent(s) are added during the second step or after the second step; the monomers of the stabilizing polymer ii), and the radical initiator v), are soluble in the synthesis solvent, and the polymer particles obtained are insoluble therein.

23. A process for treating keratin materials which comprises applying the oily dispersion as defined in claim 1 to the keratin materials.

Description

EXAMPLES

[0351] The dispersions of polymer particles presented in the various examples were prepared in 1 litre pilot reactors. The syntheses are performed in an apolar aprotic organic solvent such as isododecane.

[0352] The synthetic process is identical for all the dispersions obtained. In a first step, the statistical stabilizing polymer is synthesized by reaction between the C.sub.9-C.sub.22 alkyl (meth)acrylate and a small amount or one or two different (C.sub.1-C.sub.4)alkyl (C.sub.1-C.sub.4)(alkyl)acrylates, preferably (C.sub.1-C.sub.4)alkyl (meth)acrylates such as methyl acrylate or methyl acrylate+ethyl acrylate.

[0353] The reaction is performed at 90° C. for 2 hours. In the second step, the particle core is obtained after introducing the (C.sub.1-C.sub.4)alkyl (C.sub.1-C.sub.4)(alkyl)acrylate ethylenically unsaturated monomers, preferably (C.sub.1-C.sub.4)alkyl (meth)acrylate and optionally (C.sub.1-C.sub.4)(alkyl)acrylic acid, preferably (meth)acrylic acid such as acrylic acid; into the reaction medium containing the stabilizing polymer. This second step is performed at 90° C. for 5 hours.

[0354] Several purification steps by distillation of the solvent (isododecane), also known as “strippings”, may be performed at the end of the synthesis to remove the residual unreacted monomers.

[0355] The percentage of active material in the liquid hydrocarbon-based fatty substance(s) iii) such as isododecane is finally between 40% and 55%. All of the monomers used for the various examples and the polymerization initiator are summarized in Tables 1 and 2 below:

TABLE-US-00001 TABLE 1 Monomers used in the various examples CAS Hexyl acrylate 2499-95-8 2-Ethylhexyl acrylate 103-11-7 Isodecyl acrylate 1330-61-6 Lauryl acrylate 2156-97-0 Stearyl acrylate 4813-57-4 Behenyl acrylate 18299-85-9 Isodecyl methacrylate 29964-85-9 Lauryl methacrylate 142-90-5 Hexadecyl methacrylate 2495-27-4 Stearyl methacrylate 203743-03-7 Methyl acrylate 96-33-3 Ethyl acrylate 140-88-5 Acrylic acid 79-10-7

[0356] The polymerization initiator is Trigonox T21S. The CAS and the supplier of this initiator are given in Table 2: Polymerization initiator used in the various examples

TABLE-US-00002 TABLE 2 Free-radical initiator CAS Trigonox 21S 3006-82-4

[0357] Various examples of use of the polymers of the invention are presented on various keratin material substrates, notably skin and hair.

[0358] Examples of Implementation of the Invention

[0359] Synthesis of the Oily Dispersions with a Stabilizer Bearing a C.sub.9-C.sub.22 Alkyl Group

[0360] An example of synthesis is presented below for producing an oily dispersion with a C.sub.9-C.sub.22 alkyl (meth)acrylate stabilizer. For this example, stearyl methacrylate was used in combination with methyl acrylate for the stabilizing arm and methyl acrylate was adopted for the core of the particle.

[0361] Example of Synthesis of a Stearyl Methacrylate/Methyl Acrylate Oily Dispersion Example 13

[0362] The oily dispersions are formed as a whole (polymer particles i)+polymeric stabilizer ii)) with 94.5% of methyl acrylate and 5.5% of stearyl methacrylate. The synthesis of these oily dispersions was performed in a 1 litre pilot reactor. The synthesis is performed in two steps: [0363] In a first step, stearyl methacrylate is polymerized in isododecane in the presence of a small amount of methyl acrylate and of a radical initiator (T21S). In the first step, the stearyl methacrylate/methyl acrylate mass ratio is 85/15. [0364] In the second step, the rest of the methyl acrylate is poured in in the presence of isododecane and of the radical initiator (T21S).

[0365] After stripping, the polymer is at a solids content of 50% in the isododecane.

[0366] The ratios employed to obtain the stabilizer and the core are summarized in Table 3: Specific ratios in the stabilizer and the core for the dispersion

TABLE-US-00003 TABLE 3 Overall polymer Core composition i) + stabilizer ii) composition Stability - Mass % Mass % 1 week Example Monomer in g Monomer in g at RT* 13 Stabilizer ii) Stearyl 85 Stearyl 5.5 Fluid methacrylate methacrylate Methyl 15 acrylate Methyl 94.5 Core i) Methyl 100 acrylate acrylate *RT = room temperature

[0367] [Table 4]:

Amounts of reagents used for example 10

Step 1:

[0368]

TABLE-US-00004 Ingredients Mass (g) Stearyl methacrylate 13.75 Methyl acrylate 2.34 T21S 0.16 Isododecane iii) 60

Isododecane Added Between the Two Steps:

[0369]

TABLE-US-00005 Ingredient Mass (g) Isododecane iii) 200

Step 2:

[0370]

TABLE-US-00006 Ingredients Mass (g) Mass added to the beaker (g) Methyl acrylate 234 269.1 T21S 2.21 2.54 Isododecane iii) 234 269.1

[0371] Experimental Protocol:

[0372] Isododecane, stearyl methacrylate, methyl acrylate and T21S are introduced as feedstock into the reactor. The medium is heated to 90° C. (nominal medium temperature) under argon and with stirring. The solids content during this first step is 22%.

[0373] After heating for 2 hours, NMR indicates a stearyl methacrylate consumption of 99% (methyl acrylate consumption: 98%).

[0374] After 2 hours of reaction, isododecane is introduced. The medium is heated to 90° C.

[0375] Once the medium is at 90° C. methyl acrylate, isododecane and T21S are introduced over 1 hour by pouring. At the end of the introduction, the medium is milky.

[0376] After 7 hours of synthesis, virtually total consumption of the methyl acrylate and quantitative consumption of the stearyl methacrylate are obtained.

[0377] 400 mL of isododecane are then stripped out (the reaction progress is monitored by NMR).

[0378] Several syntheses were performed according to this same protocol. Hereinbelow, only the compositions and the nature of the monomers constituting the particles i) (the core) and the polymeric stabilizer ii) are indicated in the various tables below (% m g=mass percentage in g):

TABLE-US-00007 TABLE 5 Overall polymer Stability Core and stabilizer composition composition 1 week Ex. Monomer m % g Monomer m % g at RT 1 Comp Stabilizer Hexyl 85 Hexyl 5.5 Phase acrylate acrylate separation Methyl 15 (C.sub.6) with acrylate Methyl 94.5 setting to Core Methyl 100 acrylate a solid acrylate 2 Comp Stabilizer 2-Ethylhexyl 85 2-Ethylhexyl 5.5 — acrylate acrylate Methyl 15 (C.sub.8) acrylate Methyl 94.5 Core Methyl 100 acrylate acrylate 3 Stabilizer Isodecyl 85 Isodecyl 5.5 Fluid acrylate acrylate Methyl 15 (C.sub.10) acrylate Methyl 94.5 Core Methyl 100 acrylate acrylate 4 Stabilizer Lauryl 85 Lauryl 5.5 Fluid acrylate acrylate Methyl 15 (C.sub.12) acrylate Methyl 94.5 Core Methyl 100 acrylate acrylate

TABLE-US-00008 TABLE 6 Overall polymer Stability Core and stabilizer composition composition 1 week Ex. Monomer m % g Monomer m % g at RT 5 Stabilizer Isodecyl 85 Isodecyl 5.5 Fluid methacrylate methacrylate Methyl 15 acrylate Methyl 94.5 Core Methyl 100 acrylate acrylate 6 Stabilizer Isodecyl 85 Isodecyl 5.5 Fluid methacrylate methacrylate Methyl 15 acrylate Methyl 94.5 Core Methyl 100 acrylate acrylate 7 Stabilizer Isodecyl 85 Isodecyl 5.5 Fluid methacrylate methacrylate Methyl 15 acrylate Methyl 94.5 Core Methyl 100 acrylate acrylate 8 Stabilizer Lauryl 85 Lauryl 5.5 Fluid methacrylate methacrylate Methyl 15 acrylate Methyl 94.5 Core Methyl 100 acrylate acrylate 9 Stabilizer Hexadecyl 85 Hexadecyl 5.5 Fluid methacrylate methacrylate Methyl 15 acrylate Methyl 94.5 Core Methyl acrylate acrylate 100

TABLE-US-00009 TABLE 7 10 Stabilizer Stearyl 85 Stearyl 5.5 Fluid methacrylate methacrylate C.sub.16 Methyl 15 acrylate Methyl 94.5 Core Methyl 100 acrylate acrylate 11 Stabilizer Stearyl 89 Stearyl 10 Fluid methacrylate methacrylate Methyl 11 acrylate Methyl 90 Core Methyl 100 acrylate acrylate 12 Stabilizer Stearyl 85 Stearyl 5.5 Fluid methacrylate methacrylate Ethyl 7.5 acrylate Methyl 7.5 Ethyl 74.5 methacrylate acrylate Core Ethyl 79 Methyl 20 acrylate methacrylate Methyl 21 methacrylate

TABLE-US-00010 TABLE 8 Overall polymer Stability Core and stabilizer composition composition 1 week Ex. Monomer m % g Monomer m % g at RT 13 Stabilizer Stearyl 85 Stearyl 5.5 Fluid methacrylate methacrylate Methyl 10 acrylate Ethyl 5 Methyl 54.5 acrylate acrylate Core Methyl 58 Ethyl 30 acrylate acrylate Ethyl 32 Acrylic acid 10 acrylate Acrylic acid 10 14 Stabilizer Stearyl 85 Stearyl 5.5 Fluid methacrylate methacrylate Methyl 10 acrylate Ethyl 5 Methyl 70 acrylate acrylate Core Ethyl 58 Ethyl 14.5 acrylate acrylate Ethyl 32 Acrylic acid 10 acrylate Acrylic acid 10 15 Stabilizer Stearyl 85 Stearyl 8 Fluid methacrylate methacrylate Methyl 7.5 acrylate Ethyl 7.5 Methyl 67 acrylate acrylate Core Methyl 73 Ethyl 15 acrylate acrylate Ethyl 16 Acrylic acid 10 acrylate Acrylic acid 11

TABLE-US-00011 TABLE 9 Overall polymer Stability Core and stabilizer composition composition 1 week Ex. Monomer m % g Monomer m % g at RT 16 Stabilizer Lauryl 43 Lauryl 5 Fluid methacrylate methacrylate Behenyl 43 Behenyl 5 acrylate acrylate Methyl 14 Methyl 90 acrylate acrylate Core Methyl 100 acrylate 17 Stabilizer Stearyl 43 Stearyl 5 Fluid methacrylate methacrylate Behenyl 43 Behenyl 5 acrylate acrylate Methyl 14 Methyl 90 acrylate acrylate Core Methyl 100 acrylate

[0379] Evaluations for a Skin Application—Makeup

[0380] A formulation containing a particle dispersion of the invention (A) was prepared.

[0381] This formulation was applied to an in vitro support such as byko-charts, black scrub panels from the company Byk and left to dry for 24 hours. After 24 hours of drying, evaluations of the deposits are made: [0382] Deposition of 0.5 mL of olive oil or of sebum or of water over 5 minutes onto the deposit. [0383] After 5 minutes of contact, cotton is wiped over 15 times and the degradation of the deposit is observed.

[0384] The formulation applied to the in vitro support always has the following composition:

TABLE-US-00012 TABLE 10 Ingredients Amount in g Polymer of the invention in dispersion (A) 25% active material Pigment paste: DC Red 7 code 55025 at 6% 40% in isododecane Isododecane qs 100

TABLE-US-00013 TABLE 11 Core and stabilizer composition Overall polymer composition Example Monomer m % g Monomer m % g 2 comparative Stabilizer 2-Ethyl hexyl 85 2-Ethylhexyl 5.5 FR 3 029 786 acrylate acrylate Methyl 15 acrylate Methyl 94.5 Core Methyl 100 acrylate acrylate 3 Stabilizer Isodecyl 85 Isodecyl 5.5 acrylate acrylate Methyl 15 acrylate Methyl 94.5 Core Methyl 100 acrylate acrylate 4 Stabilizer Lauryl 85 Lauryl 5.5 acrylate acrylate Methyl 15 acrylate Methyl 94.5 Core Methyl 100 acrylate acrylate

[0385] Sebum, Olive Oil and Water Resistance Results

TABLE-US-00014 TABLE 12 Sebum Olive oil Water Ex. resistance resistance resistance Feel 2 (FR 3 − − + T 029 786) 3 + + ++ NT 4 + ++ ++ NT 5 ++ ++ ++ NT 6 + ++ ++ NT 7 + + ++ NT 8 ++ ++ ++ NT 9 ++ ++ ++ NT 10 ++ ++ ++ NT 11 − + ++ NT 12 ++ ++ ++ NT 13 + ++ ++ NT 14 + + ++ NT 15 − ++ ++ NT 18 + ++ ++ NT 17 − + ++ NT T: Tacky and NT: not tacky (−): no resistance, (+) resistance, (++), very high resistance alter 15 wipes with the same cotton fabric soaked with the same amount at sebum, olive oil or water.

[0386] It is seen that the dispersions of the invention make it possible to obtain coatings that are notably persistent with respect to sebum and to the liquid fatty substance such as olive oil, with a pleasant, non-tacky feel, unlike the dispersion of FR 3 029 786 which is not persistent with respect to fatty substances and to sebum and which has unpleasant tackiness after application to the substrate.

[0387] Evaluations for a Hair Application—Hair Makeup

[0388] Application Protocol:

[0389] The various steps of the protocol for applying to keratin fibres (natural hair containing 90% white hairs, also known as 90% NW): [0390] Application to the keratin fibres (dry hair) of composition Ax in a bath ratio of 0.5 g of dispersion or composition/g of hair, [0391] The lock is dried with a hairdryer.

[0392] The evaluations in terms of resistance to shampoo washing are thus performed 24 hours after the application. The shampoo used is the Ultra Doux shampoo from Garnier.

[0393] The various solutions prepared are:

TABLE-US-00015 TABLE 13 Dispersion A1 A2 A3 Polymer of 15% active example 5 material Polymer of 15% active example 8 material Polymer of 15% active example 10 material Red iron oxide 6% 6% 6% Isododecane qs 100 qs 100 qs 100

[0394] Results:

[0395] Colorimetric Measurements:

[0396] The colorimetric data for each of the looks are measured with a Minolta CM-3610d spectrophotometer. In this L* a* b* system, L* represents the lightness, a* indicates the green/red colour axis and b* indicates the blue/yellow colour axis. The higher the value of L, the lighter or less intense the colour. Conversely, the lower the value of L, the darker or more intense the colour. The higher the value of a*, the redder the shade, and the higher the value of b*, the yellower the shade.

[0397] The colour build-up on hair thus corresponds to the variation in colouring between the locks of dyed NW hair (natural grey hair containing 90% white hairs) and the non-dyed (i.e. untreated) NW hair, which is measured by (ΔE) according to the following equation:

ΔE=√{square root over ((L*−L.sub.o*).sup.2+(a*−a.sub.o*).sup.2+(b*−b.sub.o*).sup.2)}  [Math 1]

[0398] In this equation, L*, a* and b* represent the values measured after dyeing of the NW hair, and L0*, a0* and b0* represent the values measured before dyeing of the NW hair. The higher the ΔE value, the better the build-up of the colouring.

[0399] The results were obtained after dyeing the keratin fibres and then after one shampoo wash for the oily dispersions of the invention.

TABLE-US-00016 TABLE 14 L a b ΔE Ex. 5 Before shampooing 38.86 25.39 19.77 32.67 After shampooing 39.29 26.44 20.59 33.28 Ex. 10 Before shampooing 38.9 22.66 17.79 30.51 After shampooing 39.7 23.07 18.38 30.29

[0400] It is seen that the keratin fibres were dyed with pigments with intense and chromatic colours with a good colour build-up ΔE.

[0401] Evaluations for a Hair Application—Provision of Body to the Fibre

[0402] Application Protocol:

1. A 1 g lock of 90% NW hair 20 cm long is wound around a cylindrical brush to produce curls.
2. 2 g of a dispersion containing the polymer at 10% in isododecane are sprayed onto the lock. The lock was weighed before and after application. About 0.5 g of 10% solution is deposited on the lock.
3. The lock is measured after application and 24 hours after application (lock left at room temperature).
4. A comparison was made with a lock onto which only isododecane was sprayed.

[0403] Results:

TABLE-US-00017 TABLE 15 Lock size (cm) Isododecane Example 5 Example 8 Example 10 T.sub.0   18 cm  9 cm 14 cm 9 cm T24 h 18.5 cm 12 cm 15 cm 9 cm Number of curls T.sub.0 2 4 4 3

[0404] Conclusion:

[0405] The oily dispersions containing the stabilizer bearing a C.sub.9-C.sub.22 alkyl group give body to the hair fibre. The curls obtained after treating the keratin fibres with the dispersions of the invention are very pronounced, with curl heights, i.e. mesh lengths after treatment that are reduced by 30% to 70%), whereas the curls obtained with the liquid hydrocarbon-based fatty substance iii) isododecane are sparingly pronounced, with a very small cud radius and a long coil pitch (to be calculated from the photograph). The examples of the invention all keep a very pronounced curl effect even after 24 hours, unlike the lock treated with the liquid hydrocarbon ratty substance iii) isododecane alone. In particular, Example of stearyl methacrylate/methyl acrylate composition in a 5.5/94.5 mass ratio is very interesting because significant persistence of the cud effect was observed, without any difference in mesh curl length or in the number of curls (3) being observed after 24 hours. This is likewise the case for the lock of Example 8, which, even after 24 hours, does not lose any curls (4).

[0406] Additional Data: Comparison of the Oily Dispersions of the Invention Vs. Comparative Oily Dispersion of FR 3 014 875

[0407] A comparison was made between a dispersion (A) of the invention and a comparative particle dispersion according to FR 3 014 875.

[0408] Example 10 of the invention was compared with the oily dispersion of FR 3 014 875 (Ex. 4) consisting of 20% of isobornyl acrylate, 60% of ethyl acrylate, 10% of methyl acrylate and 10% of acrylic acid.

[0409] It is seen that the dispersion of the invention (Example 10) has better resistance to sebum than the comparative composition. This was confirmed by performing a sebum resistance test on a contrast card. Development of substantial tack on FP 40 for the comparative composition is also evidence of the sensitivity to sebum of this starting material by comparison with the dispersion of the invention (Example 10). Specifically, FP 40 contains a plasticizer which mimics sebum. Extraction of this plasticizer by the polymer in the liquid hydrocarbon-based fatty substance iii) isododecane makes it possible to simulate the sensitivity to sebum of the polymer.

TABLE-US-00018 TABLE 16 Tack on contrast card Tack on FP40 Polymer described in 0.01 0.6 FR 3 014 875 Example 10 0.05 0.04 Gloss at 20° on Gloss at 20° contrast card on FP40 Polymer described in 69 81 FR 3 014 875 Example 10 79 72

[0410] Even though the gloss values for the deposits after application of the dispersions according to the invention and the comparative dispersion are similar, the tack during drying is significantly smaller for the dispersion (A) according to the invention (Example 10) relative to the comparative oily dispersion.

Other Sebum, Olive Oil Resistance Results

Drop Test:

[0411] Initially, the dispersions of 25% raw material diluted in isododecane are deposited on a contrast card by adjusting the volume deposited/surface in order to obtain a film thickness after drying of the order of 30 μm, which represents, after drying, about 2.7 mg of an active matter/cm.sup.2. The deposits are dried 24 hours at 25° C. and 45% Relative Humidity RH to obtain films before being evaluated.
The resistance vs sebum/olive oil is evaluated after having deposited a drop of aggressor (10 μl for sebum or olive oil) on the surface of the deposit. The assessments are made after 1 hour of contact between the Sebum/Oil and the deposit. Results are the followings:

TABLE-US-00019 TABLE 17 Compositions Sebum resistance Olive oil resistance FR 3 014 875 (comparative) − + Ex. 10 (invention) ++ ++

[0412] It is seen that the dispersions of the invention make it possible to obtain coatings that are notably persistent with respect to sebum and to the liquid fatty substance such as olive oil, with a pleasant, non-tacky feel, unlike the dispersion of FR 3 014 875 which is not persistent with respect to fatty substances and to sebum and which has unpleasant tackiness after application to the substrate.

Tackiness Test after One Week of Drying:
The dispersions or 25% raw material diluted in isododecane are deposited on substrates by adjusting the volume deposited/surface in order to obtain a thickness of the film after drying of the order of 30 μm, which represents, after drying, about 2.7 mg of Active material/cm.sup.2, Two substrate types are used: a Byko Chart Lenata contrast card without interaction with the formula and an FP40 elastomer—Indeed. FP40 contains a plasticizer mimicking sebum. The extraction of this plasticizer by the polymer in isododecane simulates the sebum sensitivity of the polymer—This elastomer contains a plasticizer which is extracted by solvents such as isododecane and which, under such conditions, interacts with the deposit formed. In the past, we have observed that this plasticizer interacts in the same way as sebum with most of the deposits formed and we use it to mimic the appearance of sebum. The film obtained from composition according to invention (Ex. 10) has better sebum resistance compared to the coating obtained from composition according to the prior art FR 3 014 875 (FIG. 1). A significant development of tights on FP40 of the FR 3 014 875 testifies to the sebum sensitivity of this raw material compared to the one according to the invention.

Tackiness During the Drying

[0413] In this protocol, a drop of 10 μL of dispersed polymer in isododecane is deposited on a Byko Chart Lenata contrast card with start of the stopwatch. A series of tack measurements are always carried out at the same place by applying the following protocol: Normal force or load 1N, movement speed 5 mm.Math.s.sup.−1, contact time: 5 s with a waiting time between each cycle of measurement such that a measurement is made every minute. Results (FIG. 2) The tackiness during drying is significantly lower for the composition according the invention compared to the composition of FR 3 014 875.
On the other hand none of the tested particle according to the example of the invention smells a strong odour (neither pine nor moldy odours).