Rapid hair pH indication and solution therefor

• US 4,960,585 A
• Filed: 02/07/1990
• Issued: 10/02/1990
• Est. Priority Date: 03/02/1989
• Status: Expired due to Term

• Current Assignee: Nasser N. Tehrani
• Original Assignee: Nasser N. Tehrani
• Inventors: Tehrani, Nasser N.
• Primary Examiner(s): Ore, Dale R.
• Application Number:
  US07/476,331
• Time in Patent Office: 237 Days
• Field of Search: 424/7.1, 424/70
• US Class Current: 436/163
• CPC Class Codes: A61K 2800/45 Colour indicators, e.g. pH- or Redox indicators
• CPC Class Codes: A61K 8/44 Aminocarboxylic acids or derivatives thereof, e.g. aminocarboxylic acids containing sulfur; Salts; Esters or N-acylated derivatives thereof
• CPC Class Codes: A61K 8/49 containing heterocyclic compounds
• CPC Class Codes: A61Q 5/00 Preparations for care of the hair

Abstract

A solution for the rapid indication of hair pH and method of determining hair pH and restoration of hair to its isoionic range with buffered conditioning rinses.

Claims

1. A method for the determination of the pH of a hair sample to determine if the hair pH is within the hair isoionic range of about pH 6 to 7 comprising contacting the hair sample with a pH indicator solution for a period of time sufficient for the indicator solution to change to a color indicative of the hair being within one of three pH ranges, said solution changing to a first color when the hair pH is within the hair isoionic range of about pH 6 to 7, to a second and different color when the hair pH is acidic and below about pH 6 and to a third color different from the first and second colors when the hair pH is alkaline above about pH 7.

2. The method of claim 1 wherein the indicator solution used in the method has a conductivity of about 10,000 or more ohms at about 20°

C.

3. The method of claim 2 wherein the conductivity of the indicator solution is about 50,000 or more ohms.

4. The method of claim 1 wherein the indicator solution comprises an aqueous solution of a color indicating pH effective amounts of bromthymol blue and methyl red.

5. The method of claim 2 wherein the indicator solution comprises an aqueous solution of a color indicating pH effective amounts of bromthymol blue and methyl red.

6. The method of claim 3 wherein the indicator solution comprises an aqueous solution of a color indicating pH effective amounts of bromthymol blue and methyl red.

7. The method of claim 4 wherein the indicator solution also comprises a metal chelating effective amount of a metal chelating agent.

8. The method of claim 4 wherein the indicator solution also comprises an antioxidant effective amount of an antioxidant agent.

9. The method of claim 7 wherein the indicator solution also comprises an antioxidant effective amount of an antioxidant agent.

10. The method of claim 5 wherein the indicator solution also comprises a metal chelating effective amount of a metal chelating agent.

11. The method of claim 5 wherein the indicator solution also comprises an antioxidant effective amount of an antioxidant agent.

12. The method of claim 10 wherein the indicator solution also comprises an antioxidant effective amount of an antioxidant agent.

13. The method of claim 9 wherein the chelating agent comprises disodium EDTA and the antioxidant comprises propyl paraben.

14. The method of claim 12 wherein the chelating agent comprises disodium EDTA and the antioxidant comprises propyl paraben.

15. The method of claim 13 wherein the indicator solution comprises on a percent wt/wt basis:

space="preserve" listing-type="tabular">______________________________________ deionized water about 99.9939% bromthymol blue about 0.0025% methyl red about 0.0001% disodium EDTA about 0.0025% propyl paraben about 0.0010% ______________________________________

16. The method of claim 14 wherein the indicator solution comprises on a percent wt/wt basis:

space="preserve" listing-type="tabular">______________________________________ deionized water about 99.9939% bromthymol blue about 0.0025% methyl red about 0.0001% disodium EDTA about 0.0025% propyl paraben about 0.0010% ______________________________________

17. An indicator solution for the determination of whether a hair sample has a pH within the hair isoionic range of about pH 6 to 7 comprising a pH indicator solution which in contact with a hair sample changes to a first color when the hair pH is within the hair isoionic range of about pH 6 to 7, to a second and different color when the hair pH is acidic and below about pH 6 and to a third color different from the first and second colors when the hair pH is alkaline above about pH 7.

18. The indicator solution of claim 17 wherein the indicator solution has a conductivity of about 10,000 or more ohm at about 20°

C.

19. The indicator solution of claim 18 wherein the conductivity of the indicator solution is about 50,000 or more ohms.

20. The indicator solution of claim 17 wherein the indicator solution comprises an aqueous solution of a color indicating pH effective amounts of bromthymol blue and methyl red.

21. The indicator solution of claim 18 wherein the indicator solution comprises an aqueous solution of a color indicating pH effective amounts of bromthymol blue and methyl red.

22. The indicator solution of claim 19 wherein the indicator solution comprises an aqueous solution of a color indicating pH effective amounts of bromthymol blue and methyl red.

23. The indicator solution of claim 20 wherein the indicator solution also comprises a metal chelating effective amount of a metal chelating agent.

24. The indicator solution of claim 20 wherein the indicator solution also comprises an antioxidant effective amount of an antioxidant agent.

25. The indicator solution of claim 23 wherein the indicator solution also comprises an antioxidant effective amount of an antioxidant agent.

26. The indicator solution of claim 21 wherein the indicator solution also comprises a metal chelating effective amount of a metal chelating agent.

27. The indicator solution of claim 22 wherein the indicator solution also comprises an antioxidant effective amount of an antioxidant agent.

28. The indicator solution of claim 26 wherein the indicator solution also comprises an antioxidant effective amount of an antioxidant agent.

29. The indicator solution of claim 25 wherein the chelating agent comprises disodium EDTA and the antioxidant comprises propyl paraben.

30. The indicator solution of claim 28 wherein the chelating agent comprises disodium EDTA and the antioxidant comprises propyl paraben.

31. The indicator solution of claim 29 wherein the indicator solution comprises on a percent wt/wt basis:

space="preserve" listing-type="tabular">______________________________________ deionized water about 99.9939% bromthymol blue about 0.0025% methyl red about 0.0001% disodium EDTA about 0.0025% propyl paraben about 0.0010% ______________________________________

32. The indicator solution of claim 30 wherein the indicator solution comprises on a percent wt/wt basis:

space="preserve" listing-type="tabular">______________________________________ deionized water about 99.9939% bromthymol blue about 0.0025% methyl red about 0.0001% disodium EDTA about 0.0025% propyl paraben about 0.0010% ______________________________________

33. A method for returning hair to or maintaining hair within the hair isoionic pH range of about pH 6 to 7 comprising:

contacting a sample of said hair with sufficient pH indicator solution for a period of time sufficient for the indicator solution to change to a color indicative of hair being within one of three pH ranges, said pH indicator solution changing to a first color when the hair pH is within the hair isoionic range of about pH 6 to 7, to a second and different color when the hair pH is acidic and below about pH 6 and to a third color different from the first and second colors when the hair pH is alkaline above about pH 7, and

after determining the pH range of the hair treating the hair with a buffered rinse solution, said buffered rinse solution being buffered pH rinse solution of pH about 6.0 when the hair sample produces a color indication of alkaline hair pH, said buffered rinse solution being a buffered pH rinse solution of about pH 7.0 when the hair sample produces a color indication of acidic hair pH and said buffered rinse solution being a buffered rinse solution of pH about 6.4 to 6.5 when the hair sample produces a color indication of the hair sample being within the hair isoionic range of about pH 6 to 7.

34. The method of claim 33 wherein, on a percent wt/wt basis:

the buffered rinse solution of pH 7.0 comprises;

space="preserve" listing-type="tabular">______________________________________ deionized water about 99.49% sodium dibasic phosphate about 0.32% sodium monobasic phosphate about 0.19% ______________________________________

the buffered rinse solution of pH 6.0 comprises;

space="preserve" listing-type="tabular">______________________________________ deionized water about 99.49% sodium dibasic phosphate about 0.08% sodium monobasic phosphate about 0.43% ______________________________________

and

the buffered rinse solution of pH 6.4 to 6.5 comprises;

space="preserve" listing-type="tabular">______________________________________ deionized water about 99.49% sodium dibasic phosphate about 0.18% sodium monobasic phosphate about 0.33% ______________________________________

35. The method of claim 34 wherein the buffered rinse solution of pH about 6.0 is a blue colored solution, the buffered rinse solution of pH about 7.0 is a yellow colored solution and the buffered rinse solution of pH about 6.4 to 6.5 is a green colored solution.

36. A method of claim 33 wherein the method returns or maintains hair at about the isoionic point of pH 6.4.