Drug – bio-affecting and body treating compositions – Live hair or scalp treating compositions – Cationic surfactant containing
Reexamination Certificate
2001-11-13
2004-02-03
Page, Thurman K. (Department: 1615)
Drug, bio-affecting and body treating compositions
Live hair or scalp treating compositions
Cationic surfactant containing
C424S400000, C424S401000, C424S043000, C424S047000, C424S070100, C424S070600, C424S070110, C424S070190, C514S880000, C514S945000
Reexamination Certificate
active
06685926
ABSTRACT:
BACKGROUND OF THE INVENTION
The subject matter of the present invention includes a method and composition, which is adjusted to the isoeletric point of hair, for conditioning oxidatively dyed hair as well as a hair treatment product containing this composition.
In hair dyeing one distinguishes between temporary, semi-permanent and permanent hair dyeing. Usually synthetic direct-dyeing or natural dyestuffs, which color the hair when they are absorbed on the hair, are used for temporarily dyeing the hair, i.e. the so-called tinting of hair. Usually oxidation dyes are used for permanent and semi-permanent dyeing, in which the hair dyeing is based on oxidative development of dyestuffs from dye precursors in the interior of hair. The advantage of the direct-dyeing dyestuffs in contrast to the oxidation dyes is that they provide a safer treatment of the hair, since no oxidative damage of the hair occurs. A disadvantage of the direct-dyeing dye compounds is that they are more easily washed out of the hair and thus the dyed hair colors are more difficult to maintain. The direct-dyeing dyestuffs are more rapidly removed by washing from the hair, since they do not dye the cortex of the hair in contrast to oxidative hair dyes, but are only deposited in the scaly layer. Thus a great color change or weakening of the coverage of gray hair takes place after a few hair washings. However oxidative hair dye compounds, especially those that dye hair in the red range, are not completely resistant to more or less strong washing with hair cleansing compositions. Treatment of the hair with an oxidative hair conditioning preparation subsequent to oxidative dyeing of hair is recommended in order to counter oxidative damage to the hair. Conventional hair conditioning preparations are based on fatty alcohols and aqueous emulsions containing cationic surfactant compounds. German Patent Document DE 197 35 865 discloses a composition containing a quaternary ammonium compound, a green tea extract and a cationic polymer for improving the stability or permanence of hair colors obtained by hair dyeing. However oxidative hair dyeing and its stability to washing out with hair cleansing agents are not mentioned and this reference does not disclose that the pH of the composition is critical. The use of this type of product as an after-treatment composition after oxidative hair dyeing of course does cause a certain conditioning of the hair, but the stability of the dyes to washing and/or fading of the dyes after multiple treatments with hair cleaning compositions is not satisfactory.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method and composition for conditioning oxidatively dyed hair and at the same time to extend the permanence or stability of the dyed hair colors obtained during the oxidative dyeing of the hair toward washing process.
This object and others, which will be made more apparent hereinafter, are attained by an aqueous hair conditioning preparation adjusted to the isoelectric point of human hair.
During after-treatment of oxidatively dyed hair with a preparation comprising at least one hair-conditioning cationic polymer and adjusted to the isoelectric point of human hair, it was found that the dyed hair, which was treated with the preparation according to the invention, simultaneously was well conditioned and had an improved color stability in contrast to the wash out effect produced with conventional conditioning compositions and subsequent shampooing.
The subject matter of the invention thus includes an aqueous preparation for conditioning of hair dyed with an oxidative dyestuff, which contains at least one polymer with a cationic group and which is adjusted to the isoelectric point of human hair.
Hair comprises proteins. Proteins are characterized, among other things, by an isoionic point and an isoelectric point (C. R. Robbins, Chemical and Physical Behavior of Human Hair, 3
rd
Edition, pp. 204-206,267). The isoionic point is that pH value, at which the number of total positive charges on the protein is equal to the number of total negative charges. The isoionic point of hair is about equal to pH 6.0. The isoelectric point is a surface property of solid proteins and is that pH value at which the number of positive charges on the surface of the protein equals the number of negative charges. The isolectric point of human hair normally is about pH=3.7. The exact value for individual hair can vary slightly from this value. The preparation according to the invention, which has the isoelectric point adjusted to that of human hair, has pH values in a range between 3.4 and 3.9, preferably in a range from 3.5 to 3.8, and especially preferably in a range from 3.6 to 3.8.
Comparative experiments have shown that a hair conditioning composition adjusted to a pH of 3.7 or 3.8 provides improved color stability to washing out than when it has a pH=4.5. Especially good color stability is achieved by the simultaneous use of cationic polymers. Dimethyldiallylammonium chloride/acrylamide copolymer (Polyquaternium-7, MERQUAT® 550L) is a particularly preferred cationic polymer.
Aerosol foam is the preferred application form for the preparation according to the invention. An appropriate aerosol-foam product according to the invention comprises
(a) a pressure-resistant container,
(b) a foam head,
(c) a foam-forming aqueous solution containing at least one polymer, which has a cationic group, adjusted to the isoelectric point of human hair, and
(d) at least one propellant.
The polymers with cationic groups are preferably contained in an amount of from 0.001 to 2.5 percent by weight, especially preferably from 0.002 to 1.5 percent by weight. Cationic polymers in the sense of the present invention are those polymers, which contain at least one cationic group or cationizable group by protonation. Quaternary amine groups are, for example, cationic groups. Cationizable groups are, for example, primary, secondary or tertiary amine groups. The cationic polymers can be homopolymers or copolymers. The cationic or cationizable groups are contained either in polymer chains or preferably in one or more monomers acting as substituents.
Suitable monomers of the cationic polymers, which have cationizable groups, are unsaturated radically polymerizable compounds, which carry at least one neutralizable or non-neutralizable basic group. The basic groups can especially be primary, secondary or tertiary amine groups, in which the amine nitrogen can also be part of a ring. Monoalkylaminoalkylacrylates, dialkylaminoalkylacrylates, Monoalkylaminoalkylmethacrylates and dialkylaminoalkylmethacrylates are examples of this sort of monomer. The alkyl groups of these monomers are preferably lower alkyl groups, such as those with from one to seven carbon atoms, preferably from one to four carbon atoms.
Suitable monomers, which have quaternary amine groups, include unsaturated, radically polymerizable compounds, which contain at least one quaternary amine group, especially ammonium-substituted vinyl monomers or quaternized derivatives of carboxyvinyl monomers, such as quaternized acrylamides or methacrylamides. For example, acrylamidoalkyltrialkylammonium halogenides or methacrylamidoalkyltrialkylammonium halogenides, trialkylmethacryloxyalkylammonium halogenides, trialkylacryloxyalkylammonium halogenides, dialkyldiallylammonium halogenides or quaternary vinylammonium monomers with cyclic cationic nitrogen-containing groups, such as pyridinium, imidazolium or quaternary pyrrolidones, e.g. alkylvinylimidazolium, alkylvinylpyridinium, or alkylvinyl pyrrolidone salts. The alkyl groups of these monomers are preferably lower alkyl groups, for example C
1
- to C
7
-alkyl groups, especially preferably C
1
- to C
3
-alkyl groups. Acrylamidopropyltrimethylammonium chloride and methacrylamidopropyltrimethylammonium chloride are preferred.
The cationic polymer can be, if necessary, polymerized with neutral comonomers, which contain neither cationic nor cationizable groups. These neutral comonomers are, for exa
Braun Petra
Deutz Herbert
Flemming Ernst
Hehner Ursula
Evans Charesse
Page Thurman K.
Striker Michael J.
Wella Aktiengesellschaft
LandOfFree
Method and composition adjusted to the isoelectric point of... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and composition adjusted to the isoelectric point of..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and composition adjusted to the isoelectric point of... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3296855