Reducing composition for permanently reshaping keratin fibers

Abstract

A process for permanently reshaping keratin fibers comprising mixing a component A and a component B to form a reducing composition. The component A comprises at least one thiol-based reducing compound having one thiol group selected from the group consisting of thioglycolic acid and derivatives thereof, thiolactic acid and derivatives thereof, 3-mercaptopropionic acid and derivatives thereof, and cysteine and derivatives thereof, and has pH 7.0 or less and the component B comprises at least one buffer salt selected from the group consisting of carbonates, bicarbonates and carbamates, and has pH 8.0 or more, wherein at least one of the component A and component B comprises at least one disulfide compound that is further defined, and wherein the reducing composition has a pH ranging from 7.0 to 7.8 and a viscosity ranging from 500 cps to 100,000 cps. The reducing composition is then applied to the keratin fibers.

Claims

1. A process for permanently reshaping keratin fibers comprising: mixing a component A and a component B to form a reducing composition, wherein the component A comprises at least one thiol-based reducing compound having one thiol group selected from the group consisting of thioglycolic acid and derivatives thereof, thiolactic acid and derivatives thereof, 3-mercaptopropionic acid and derivatives thereof, and cysteine and derivatives thereof, and has pH 7.0 or less, the component B comprises at least one buffer salt selected from the group consisting of carbonates, bicarbonates and carbamates, and has pH 8.0 or more, wherein at least one of the component A and component B comprises at least one disulfide compound which is a separate compound that corresponds to the thiol-based reducing compound having one thiol group, and wherein the reducing composition has a pH ranging from 7.0 to 7.8 and a viscosity ranging from 500 cps to 100,000 cps; and applying the reducing composition to the keratin fibers.

2. The process according to claim 1, wherein the reducing composition further comprises at least one surfactant selected from the group consisting of cationic, anionic, nonionic and amphoteric surfactants.

3. The process according to claim 2, wherein the surfactant is a cationic surfactant selected from the group consisting of alkyltrimethylammonium salts.

4. The process according to claim 2, wherein the surfactant is a nonionic surfactant selected from the group consisting of polyoxyethylene alkyl fatty ethers.

5. The process according to claim 1, wherein the component A has pH ranging from 3.5 to 6.5.

6. The process according to claim 1, wherein the component B has pH ranging from 8.0 to 9.0.

7. The process according to claim 1, wherein the buffer salt is selected from the group consisting of bicarbonates.

8. The process according to claim 1, wherein the disulfide compound is a dithiodiglycolate.

9. The process according to claim 1, wherein at least one of the component A and the component B further comprises at least one sequestering agent and/or at least one pH regulator, the pH regulator being other than carbonates, bicarbonates and carbamates for component B.

10. The process according to claim 1, further comprising at least one step of heating the keratin fibers after the applying.

11. The process according to claim 10, further comprising the following steps after applying the reducing composition to the keratin fibers: (i) rinsing said keratin fibers with water and optionally drying the keratin fibers; (ii) setting said keratin fibers under mechanical tension; (iii) heating said keratin fibers; and (iv) applying onto said keratin fibers an oxidizing composition comprising at least one oxidizing compound.

12. The process according to claim 11, further comprising a step of moistening the keratin fibers before applying the reducing composition.

13. The process according to claim 11, further comprising a step of leaving the keratin fibers for 10 to 30 minutes after applying the reducing composition and before the rinsing step.

14. The process according to claim 11, further comprising a step of leaving the keratin fibers for 5 to 15 minutes after applying the oxidizing compound, followed by a step of rinsing said keratin fibers with water and optionally drying said keratin fibers.

15. The process according to claim 11, wherein the step (ii) is a step of winding said keratin fibers on a rod.

16. The process according to claim 11, wherein the step (ii) is a step of straightening said keratin fibers with an iron.

17. The process according to claim 11, wherein the oxidizing compound is at least one selected from the group consisting of hydrogen peroxide, alkaline bromate, polythionates and persalts.

18. The process according to claim 11, wherein the heating of the keratin fibers is at a temperature ranging from 60 to 250° C.

19. The process according to claim 1, wherein the keratin fibers are hair.

Description

EXAMPLES

(1) The present invention will be described in more detail by way of examples, which however should not be construed as limiting the scope of the present invention.

(2) Preparation 1: Preparation for Component A

(3) Component A1 was prepared according to the formulation shown in Table 1. The resulting component A was liquid and pH value thereof was 5.0.

(4) TABLE-US-00001 TABLE 1 Component A1 Ingredients wt % Pentasodium pentetate (40% in aq. Solution) 0.4 Thioglycolic acid 10.2 Ammonium thioglycolate (71% in aq. Solution) 53 Ammonium thiolactate (58% in aq. Solution) 12 Water qs to 100

(5) Preparations 2 to 4: Preparations for Component B

(6) Components B1 to B3 were prepared according to the formulations shown in Table 2. The resulting components B1 to B3 were emulsions.

(7) TABLE-US-00002 TABLE 2 Component Component B1 Component B2 B3 Ingredients wt % wt % wt % Behentrimonium Chloride 3 3 3 Ceteareth-25 2 2 2 Ceteth-2 1 1 1 Cetanol 3 3 3 Mineral oil 2 2 2 Pentasodium pentetate 0.4 0.4 0.4 (40% in aq. Solution) Ammonium bicarbonate 4 8 — Diammonium 7.3 7.3 7.3 dithiodiglycolate (48% in aq. Solution) Ethanolamine pH adjust pH adjust pH adjust (pH 8) (pH 8) (pH 8) Water qs to 100 qs to 100 qs to 100

(8) Preparation 5: Preparations for Control

(9) As control, a conventional reducing composition with alkaline pH was prepared according to the formulation shown in Table 3. The resulting control was liquid and pH value thereof was 9.

(10) TABLE-US-00003 TABLE 3 Control Ingredients wt % Pentasodium pentetate (40% in aq. Solution) 0.4 Ammonium thioglycolate (71% in aq. Solution) 15 Behentrimonium Chloride 2.3 Ceteareth-25 1.4 Ceteth-2 0.8 Cetanol 2.1 Mineral oil 1.2 Diammonium dithiodiglycolate (48% in aq. Solution) 5 Ethanolamine 1.2 Ammonium hydroxide (20% in aq. Solution) 2 Water qs to 100

Example 1

(11) Component A1 and component B1 obtained in Preparations 1 and 2 respectively were mixed in a weight ratio of 1:3 at the time of being subjected to the following evaluation method. Results of the evaluations have been shown in Table 4.

(12) <Evaluation Method for Digital Perm>

(13) Hair was moistened and then the reducing composition of Example 1 was applied to the hair. The hair was left for 15 minutes and then rinsed thoroughly with water. The hair was winded on a rod for a digital perm and then heated for 25 minutes at temperature 90° C. An oxidizing composition comprising hydrogen peroxide was applied to the hair and left for 5 minutes, and then the hair was rinsed thoroughly with water and dried.

(14) The hair which had been treated as above was evaluated sensorially by experts on the evaluation points “Wave intensity”, “Wave bounciness”, “Smoothness” and “Suppleness”.

Example 2

(15) Component A1 and component B2 obtained in Preparations 1 and 3 respectively were mixed in a weight ratio of 1:3 at the time of being subjected to the above evaluation method for digital perm. Results of the evaluations have been shown in Table 4.

Comparative Example 1

(16) Component A1 and component B3 obtained in Preparations 1 and 4 respectively were mixed in a weight ratio of 1:3 at the time of being subjected to the above evaluation method for digital perm. Results of the evaluations have been shown in Table 4.

Comparative Example 2

(17) Control obtained in Preparation 5 was subjected to the above evaluation method for digital perm. Results of the evaluations have been shown in Table 4.

(18) TABLE-US-00004 TABLE 4 Reducing composition viscosity Wave Wave (mixing ratio) pH (cps) intensity bounciness Smoothness Suppleness Example 1 A1 + B1 7 8,000-8,500 ± ± + + (1:3) Example 2 A1 + B2 7 8,000-8,500 + + + + (1:3) Comparative A1 + B3 7 8,000-8,500 − − + + Example 1 (1:3) Comparative Control 9 10,000-10,500 + ± ± − Example 2

(19) Evaluation criteria shown in the symbols “+”, “±” and “−” on each evaluation point in Table 4 have the following meanings.

(20) Wave intensity: +: better wave efficiency; ±: Neither; −: less wave efficiency

(21) Wave bounciness: +:better bounciness; ±: Neither; −: less bounciness

(22) Smoothness: +:better smoothness; ±: Neither; −: less smoothness

(23) Suppleness: +:better suppleness; ±: Neither; −: less suppleness

Example 3

(24) Component A1 and component B1 obtained in Preparations 1 and 2 respectively were mixed in a weight ratio of 1:3 at the time of being subjected to the following evaluation method. Results of the evaluations have been shown in Table 5.

(25) <Evaluation Method for Iron Straightener>

(26) Hair was moistened and then the reducing composition of Example 3 was applied to the hair. The hair was left for 15 minutes and then rinsed thoroughly with water. The hair was dried about 80% using a dryer and then ironed at temperature 180° C. The hair was parted into 4 sections. Next, the hair was gently combed through parting. Then the hair was ironed approximately ⅛ inch from scalp. Each parting was ironed 2 to 3 times. This process was repeated until all hair has been ironed. An oxidizing composition comprising hydrogen peroxide was applied to the hair and left for 5 minutes, and then the hair was rinsed thoroughly with water and dried.

(27) The hair which had been treated as above was evaluated sensorially by experts on the evaluation points “Straightening effect”, “Volume down”, “Smoothness” and “Suppleness”.

Example 4

(28) Component A1 and component B2 obtained in Preparations 1 and 3 respectively were mixed in a weight ratio of 1:3 at the time of being subjected to the above evaluation method for iron straightener. Results of the evaluations have been shown in Table 5.

Comparative Example 3

(29) Component A1 and component B3 obtained in Preparations 1 and 4 respectively were mixed in a weight ratio of 1:3 at the time of being subjected to the above evaluation method for iron straightener. Results of the evaluations have been shown in Table 5.

Comparative Example 4

(30) Control obtained in Preparation 5 was subjected to the above evaluation method for iron straightener. Results of the evaluations have been shown in Table 5.

(31) TABLE-US-00005 TABLE 5 Reducing composition viscosity Straightening Volume (mixing ratio) pH (cps) effect down Smoothness Suppleness Example 3 A1 + B1 7 8,000-8,500 ± ± + + (1:3) Example 4 A1 + B2 7 8,000-8,500 + + + + (1:3) Comparative A1 + B3 7 8,000-8,500 − − + + Example 3 (1:3) Comparative Control 9 10,000-10,500 + + ± − Example 4

(32) Evaluation criteria shown in the symbols “+”, “±” and “−” on each evaluation point in Table 5 have the same meanings as defined in Table 4.