Process for treating keratin substances using a composition comprising a modified photo-dimerizable polymer

Abstract

The present invention relates to a general process for treating keratin substances, preferably keratin fibres, comprising the following steps: c) applying to the keratin substances a composition comprising at least one photo-crosslinkable polymer including at least one photo-dimerizable pendant group and at least one hydrophobic pendant group, and d) irradiating said composition on the keratin substances to crosslink the polymer.

Claims

1. A method for treating hair, comprising: a) applying to the hair a composition comprising a photo-crosslinkable polymer, wherein the photo-crosslinkable polymer is: ##STR00040## wherein: Q.sup.− is CH.sub.3OSO.sub.3−; the total amount of the units bearing the stilbazolium pendent group, represented by m, ranges from 0.5% to 5%; the total amount of the units bearing the alkyl group, represented by n, ranges from 2% to 20%; and the total amount of the units bearing oxygen, represented by p, ranges from 5% to 97.5%; wherein all percentages are by mole, based on the total amount of the photo-crosslinkable polymer; and b) irradiating the composition on the hair to crosslink the polymer.

2. The method of claim 1, wherein the photo-crosslinkable polymer is soluble or dispersed in the composition.

3. The method of claim 1, wherein the photo-crosslinkable polymer is in the form of particles.

4. The method of claim 1, wherein the photo-crosslinkable polymer is present in an amount ranging from 0.01% to 25% by weight, relative to the total weight of the composition.

5. The method of claim 1, wherein the photo-crosslinkable polymer is present in an amount ranging from 1% to 15% by weight, relative to the total weight of the composition.

6. The method of claim 1, wherein the composition further comprises at least one solvent chosen from water, alcohols, polyols, polyol ethers, or mixtures thereof.

7. The method of claim 6, wherein the at least one solvent is present in an amount ranging from 0.1% to 99% by weight, relative to the total weight of the composition.

8. The method of claim 1, wherein the composition further comprises at least one fatty substance.

9. The method of claim 1, further comprising drying the hair, before the irradiation step and/or after the application step.

10. The method of claim 1, further comprising leaving the composition on the keratin substances for a period of time at room temperature, or under red light, before and/or after the irradiation step.

11. The method of claim 1, wherein the composition on the hair is irradiated with radiation in the UVA or the visible domain.

12. The method of claim 11, wherein the UVA radiation is between 250 nm and 400 nm.

Description

EXAMPLES

Example 1

(1) Polymer PVA-SbQ-Propional was obtained according to the process described previously.

(2) 4 g of PVA-SbQ propional solution at 5% Al of polymer was dried in a Teflon mould to form a PVA-SbQ propional film. The film obtained was irradiated under UVA at 365 nm for an energy of 8 J/cm.sup.2. The film was then placed in a beaker of water with stirring for 48 h. The film obtained is insoluble and remains intact after 1 h. After 48 h, the film is a little fragmented, in quite large pieces.

(3) 4 g of PVA-SbQ solution at 5% Al of polymer was dried in a Teflon mould to form a PVA-SbQ film. The film obtained was irradiated under UVA at 365 nm for an energy of 8 J/cm.sup.2. The film was then placed in a beaker of water with stirring for 48 h. The film fragments after 1 h. After 48 h, the film remains as insoluble but fragments in more pieces.

Example 2

(4) The following compositions were made in inverse emulsion form (quantity in % weight of active ingredient)

(5) TABLE-US-00001 A (Inven- B (Inven- C (Compar- Con- tion 1) tion 2) ative) trol Isopropyl myristate 10 10 10 10 Propylene glycol 2.5 2.5 2.5 2.5 Cetyl PEG/PPG-10/1 1 1 1 1 dimethicone PVA-SbQ* 8 PVA-SbQ-propional 8 8 — Bis-cetearyl dimethicone 1.5 Dimethicone 1.5 Water qs 100 100 100 100 *partially saponified polyvinylacetate polymer bearing stilbazolium groups, adsorbed on polyvinylacetate particles (15% of dry extract).

(6) Composition A according to the invention was applied to fine, short hair at 2 to 4 g of composition per half head. The hair treated was irradiated under UVA at 365 nm for an energy of 8 J/cm.sup.2.

(7) After the application and after 1 and 5 washes with shampoo, provision of style and cosmetic was observed. In particular, a clear provision of style, volume, density and body is observed up to 5 washes with shampoo.

(8) Compositions A and C were also applied to tresses of wet natural hair with 90% grey hair, that were dried then irradiated under UVA at 365 nm for an energy of 8 J/cm.sup.2. The tresses were then treated with a dye composition obtained from a solution that comprises: 0.4668 g of RED 80 colorant (SIRIUS ROT F3B-Bayer), 0.125 ml of pure acetic acid, and water qs 100 ml.

(9) This solution is diluted 5 times to obtain the dye composition.

(10) The tresses treated are washed 10 times with shampoo.

(11) A Datacolor Spectra Flash SF600X spectrophotometer was used to evaluate variation in tress colour.

(12) Colorant “red 80”, which has an affinity with the polymer, allows evaluation of the quantity of polymer remaining after several washes with shampoo.

(13) The colour of tresses was evaluated before and after washing, in the L*a*b* system. In this L*a*b* system, the three parameters denote, respectively, the intensity (L*), a* indicates the green/red colour axis and b* the blue/yellow colour axis.

(14) The variation in the tress colour before and after washes is measured (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)}

(15) In this equation, L*, a* and b* represent the values measured after washing and L0*, a0* and b0* represent the values measured before washing.

(16) The larger the value of ΔE, the greater the difference in colour before and after washing operations, and in the present case, the less persistent the film is.

(17) The results are reported in the table below.

(18) TABLE-US-00002 After 5 washes After 10 washes T0 with shampoo with shampoo C (comparative) L* = 40.3 ΔE = 20.8 ΔE = 23.5 a* = 33.6 b* = 13.8 A (Invention 1) L* = 40.8 ΔE = 5.7 ΔE = 10.0 a* = 33.9 b* = 15.0

(19) These results show an improvement in persistence of the sleeve after 10 washes with shampoo with the composition of the invention compared with the comparative composition that contains a PVA-SbQ polymer without a hydrophobic group.

Example 3

(20) The following compositions were made in inverse emulsion form (quantity in % weight of active ingredient)

(21) TABLE-US-00003 C1 D E F G (Comparative) PVA-SbQ* — — — — 2 Propyl-PVA-SbQ 2 — — — — Butyl-PVA-SbQ — 2 — — — Hexyl-PVA-SbQ — — 2 — — Octyl-PVA-SbQ — — — 2 — Water Qs 100 Qs 100 Qs 100 Qs 100 Qs 100 *partially saponified polyvinylacetate polymer bearing stilbazolium groups, adsorbed on polyvinylacetate particles (15% of dry extract).

(22) Compositions D to F according to the invention and C1 were also applied to to tresses of wet natural hair with 90% grey hair, on the one hand, and on tresses of permanent hair, on the other hand, at the rate of 1.6 g of composition per gram of hair. These tresses were dried then irradiated under UVA at 365 nm for an energy of 8 J/cm.sup.2. The tresses were then treated with a dye composition described in Example 2. The tresses thus treated were then subjected to 5 washings with shampoos.

(23) As in Example 2, the variation in color of the tresses was evaluated by looking at the tresses before and after washes in the L*a*b* system.

(24) An improvement in persistence of the sleeve after 5 washes with shampoo with compositions D to F of the invention compared with the comparative composition C1 that contains a PVA-SbQ polymer without a hydrophobic group was observed.