Reducing composition for permanently reshaping keratin fibers

Abstract

Provided is a reducing composition for permanently reshaping keratin fibers such as hair, prepared by mixing a component A and a component B at the time of use, wherein the component A comprises at least one thiol-based reducing compound 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; at least one of the component A and component B comprises at least one disulfide compound; and the prepared reducing composition has pH ranging from 7.0 to 7.8.

1 . A reducing composition for permanently reshaping keratin fibers such as hair, prepared by mixing a component A and a component B at the time of use, 
       wherein
 the component A comprises at least one thiol-based reducing compound 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, 
 at least one of the component A and component B comprises at least one disulfide compound, and 
 
       the reducing composition prepared has pH ranging from 7.0 to 7.8 
     
     
         2 . The composition according to  claim 1 , wherein the composition has a viscosity ranging from 500 cps to 100,000. 
     
     
         3 . The composition according to  claim 1 , wherein the composition further comprises at least one surfactant selected from the group consisting of cationic, anionic, nonionic and amphoteric surfactants. 
     
     
         4 . The composition according to  claim 3 , wherein the surfactant is a cationic surfactant selected from the group consisting of alkyltrimethylammonium salts. 
     
     
         5 . The composition according to  claim 3 , wherein the surfactant is a nonionic surfactant selected from the group consisting of polyoxyethylene alkyl fatty ethers. 
     
     
         6 . The composition according to  claim 1 , wherein the component A has pH ranging from 3.5 to 6.5. 
     
     
         7 . The composition according to  claim 1 , wherein the component B has pH ranging from 8.0 to 9.0. 
     
     
         8 . The composition according to  claim 1 , wherein the buffer salt is selected from the group consisting of bicarbonates. 
     
     
         9 . The composition according to  claim 1 , wherein the thiol-based reducing compound is selected from the group consisting of thioglycolic acid and derivatives thereof; dithioglycolic acid and derivatives thereof; thiolactic acid and derivatives thereof; 3-mercaptopropionic acid and derivatives thereof; cysteamine and derivatives thereof; mono-thioglycerol and derivatives thereof; and cysteine and derivatives thereof. 
     
     
         10 . The composition according to  claim 1 , wherein the disulfide compound is a disulfide of a thiol. 
     
     
         11 . The composition 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. 
     
     
         12 . A process for permanently reshaping keratin fibers such as hair using the reducing composition as defined in  claim 1  and comprising at least one step of heating. 
     
     
         13 . The process according to  claim 12 , comprising the following steps of:
 (i) applying onto the keratin fibers the reducing composition;   (ii) rinsing said keratin fibers with water and optionally drying the keratin fibers;   (iii) setting said keratin fibers under mechanical tension;   (iv) heating said keratin fibers, preferably at a temperature ranging from 60 to 250° C.; and   (v) applying onto said keratin fibers an oxidizing composition comprising at least one oxidizing compound.   
     
     
         14 . The process according to  claim 13 , further comprising a step of moistening the keratin fibers before the application step (i). 
     
     
         15 . The process according to  claim 13 , further comprising a step of leaving the keratin fibers for 10 to 30 minutes after the application step (i) and before the rinsing step (ii). 
     
     
         16 . The process according to  claim 13 , further comprising a step of leaving the keratin fibers for 5 to 15 minutes after the application step (v), followed by a step of rinsing said keratin fibers with water and optionally drying said keratin fibers. 
     
     
         17 . The process according to  claim 13 , the step (iii) is a step of winding said keratin fibers on a rod. 
     
     
         18 . The process according to  claim 13 , the step (iii) is a step of straightening said keratin fibers with an iron. 
     
     
         19 . The process according to  claim 13 , wherein the oxidizing compound is at least one selected from the group consisting of hydrogen peroxide, alkaline bromate, polythionates and persalts. 
     
     
         20 . A kit for permanently reshaping keratin fibers such as hair, comprising:
 a component A comprising at least one thiol-based reducing compound and having pH 7.0 or less;   a component B comprising at least one buffer salt selected from the group consisting of carbonates, bicarbonates and carbamates, and having pH 8.0 or more;   
       wherein at least one of the component A and component B comprises at least one disulfide compound, and the component A and component B are mixed to prepare a reducing composition having pH ranging from 7.0 to 7.8,
 and optionally further comprising:
 an oxidizing composition comprising at least one oxidizing compound.