Drug – bio-affecting and body treating compositions – Live hair or scalp treating compositions – Permanent waving or straightening
Reexamination Certificate
1999-03-27
2001-07-24
Page, Thurman K. (Department: 1615)
Drug, bio-affecting and body treating compositions
Live hair or scalp treating compositions
Permanent waving or straightening
C424S070100, C132S203000
Reexamination Certificate
active
06264932
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a composition for permanent hair waving based on straight-chain N—C
3
—to N—C
3
-C
6
-alkyl- or N—C
3
-C
6
-hydroxyalkyl-substituted mercaptoacetamides, as the keratin-reducing ingredient, and to a method for permanent hair waving using this composition.
2. Prior Art
The classic technique for permanent hair waving is familiarly based on two treatment steps: In the first step, the cystine-disulfide bridges of the keratin of the hair are opened by the action of an agent that contains a reducing ingredient (waving composition). The hair is then put into the desired form. In a second step, cystine-disulfide bonds are closed again using a fixative, that is, an agent containing an oxidant ingredient.
As the pioneering work in German patents 948 186 and 972 424 demonstrate, thioglycolic acid, for instance in the form of an ammonium or monoethanolamine salt, is used as a classic permanent hair waving reducing agent. Other typical reducing agents are 2-mercaptopropionic acid (thiolactic acid), 3-mercaptopropionic acid, cysteine, and derivatives of these compounds, as well as certain mercaptocarboxylic acid esters.
Alkaline-adjusted preparations based on mercaptocarboxylic acid esters, despite being adequately effective, cause hair damage, which is expressed for instance in increased hair breakage. Often, these compositions also undesirably stress the scalp. Finally, the unpleasant odor of the reducing agents used requires intensive perfuming of the products. By using 2-mercaptopropionic acid, it is possible to solve some of these problems. However, in comparison to thioglycolic acid, which is widely used, thiolactic acid produces weaker waves.
For gentle, permanent waving of damaged and especially bleached or dyed hair, waving compositions that are adjusted to be slightly acidic to neutral are preferably used. From a professional standpoint, over the last 35 years, the thioglycolic acid esters have proved to be the reducing agents best suited for this purpose.
A major disadvantage of acidic hair waving compositions based on thioglycolic acid esters, however, is that they are poorly tolerated by the eyes and skin, and the sensitizing effect of the thioglycolic acid esters, so that the use of these hair waving compositions is widely avoided at present. Instead of the mercaptocarboxylic acid esters, mercaptoacetamides such as thioglycolic acid amide or alkyl- or hydroxyalkyl-substituted amides have also been used. Such compounds are known from German Patent DE-C1 144 440 and European Patent EP-A 0 455 457. Like the mercaptocarboxylic acid esters, these substances have a high waving potential at low pH values, but in terms of toxicology they are even more critical than the mercaptocarboxylic acid esters.
SUMMARY OF THE INVENTION
It is therefore the object of the invention to make available a composition and a method for permanent hair waving that both in the acidic and the slightly alkaline range (pH—2 to 9.5), and above all in the pH range from 4.0 to 8.5, makes gentle, uniform hair waving possible, has no or only a slight sensitizing potential, and furthermore has a stronger hair waving potential than 2-mercaptopropionic acid (thiolactic acid).
Surprisingly, it has now been discovered that the above disadvantages can be overcome by the use of certain N-alkylmercaptoacetamides, and that they have a stronger hair waving potential than thiolactic acid.
The subject of the present invention is therefore a composition for permanent hair waving, which is characterized in that as its keratin-reducing ingredient, it contains an N-alkylmercaptoacetamide of the formula
in which R stands for a straight-chain alkyl radical with from 3 to 6 carbon atoms, or a straight-chain hydroxyalkyl radical with from 3 to 6 carbon atoms, or its salt.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferably, the straight-chain hydroxyalkyl radical has one or two hydroxyl groups.
Preferred N-alkylmercaptoacetamides of formula (I) are N-propyl-2-mercaptoacetamide, N-(2′-hydroxypropyl)-2-mercaptoacetamide, and N-(3′-hydroxypropyl)-2-mercaptoacetamide.
Possible salts include above all the hydrogen salts of the acids in the group comprising hydrochloric acid, sulfuric acid, acetic acid or citric acid.
The N-alkylmercaptoacetamide of formula (I) is preferably contained as the sole keratin-reducing ingredient in the composition. However, it may also be used in combination with other keratin-reducing ingredients—such as thioglycolic acid, thiolactic acid, 2-hydroxy-3-mercaptopropionic acid, cysteamine and cysteamine derivatives such as alkyl- or acylcystamine or cysteine and cysteine derivatives, such as cysteine-(2-hydroxyethyl)ester or L-cysteine glycerine ester or sulfites.
The N-alkylmercaptoacetamide of formula (I) is contained in the ready-to-use composition for permanent hair waving in a quantity of from 3 to 28 weight-%, preferably 5 to 21 weight-%.
The ready-to-use hair waving composition preferably has a pH value of from 2.0 to 9.5 and especially preferably from 4.0 to 8.5. As an alkalizing agent or agent for adjusting the pH value, ammonia or caustic soda is especially suitable, but water-soluble, physiologically tolerable salts of organic and inorganic bases can also be considered, such as ammonium hydrogen carbonate. To establish an acidic pH value, hydrochloric acid, acetic acid or citric acid can be used in particular.
The waving composition may be sold in single- or dual- or triple-component packages; the composition may be in the form of an aqueous solution, or an emulsion, or in thickened water-based form, especially a creme, gel, foam or paste.
It is understood that the waving composition may contain all the usual and known additives for such compositions, such as thickeners, such as bentonite, fatty acids, starch, polyacrylic acid and its derivatives, cellulose derivatives, alginates, vaseline, and paraffin oils; wetting agents or emulsifiers from the classes of anionic, cationic, amphoteric or nonionic surfactants, such as fatty alcohol sulfates, fatty alcohol ether sulfates, alkyl sulfonates, alkylbenzene sulfates, quaternary ammonium salts, alkyl betaines, ethoxylated alkylphenols, fatty acid alkanolamides or ethoxylated fatty acid esters; and opacifiers, such as polyethyleneglycol esters; alcohols, such as ethanol, propanol, isopropanol, polyols such as 1,2- or 1,2-propanediol, 1,2-, 1,3- or 1,4-butanediol, 1,2-pentanediol and glycerine; sugars such as D-glucose; solubilizers, stabilizers, buffer substances, perfume oils, dyes, and hair-conditioning and hair-care ingredients, such as cationic polymers, lanolin derivatives, cholesterol, pantothenic acid, and betaine.
The aforementioned ingredients are used in quantities usual for such purposes; for example, the wetting agents and emulsifiers in concentrations of a total of 0.2 to 30 weight-%, the alcohols in a total quantity of 0.1 to 20 weight-%, the opacifiers, perfume oils and dyes in a quantity of 0.01 to 1 weight-% each, the buffer substances in a total quantity of 0.1 to 10 weight-%, and sugars, solubilizers, stabilizers and hair-conditioning and hair-care ingredients in a quantity of 0.1 to 5 weight-% each, while the thickeners and solubilizers may be contained in this composition in a total quantity of 0.5 to 20 weight-%.
So-called swelling agents and penetrating substances can also be added to this composition, examples being dipropyleneglycol monomethyl ether, 2-pyrrolidone or imidazolidin-2-one, in a quantity of 1 to 30 weight-%, and to avoid making the hair too kinky, dithio compounds, such as dithioglycolic acid, dithiolactic acid, the disulfides of these compounds, or their salts.
By varying the pH value, a composition can be made available that is universally suitable for every hair structure, optionally with the additional application of heat. The composition brings about an elastic, durable and uniform waving from the root of the hair to the ends, without eliciting allergic or sensitizing reactions.
The present invention also relates to a
Dannecker Beate
Hanefeld Wolfgang
Lang Gunther
Walther Heiko
Di Nola-Baron Liliana
Page Thurman K.
Striker Michael J.
Wella Aktiengesellschaft
LandOfFree
Agent and method for permanent shaping of hair and method... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Agent and method for permanent shaping of hair and method..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Agent and method for permanent shaping of hair and method... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2563645