HAIR DYE

Abstract

Disclosed is the field of cosmetic products, in particular, a hair dye, of the permanent coloring type, including: a mixture including primary dyes, couplers, at least one alkalizing substance, a buffer substance, an antioxidant substance; and at least one oxidizing agent. The alkalizing substance is contained in an alkaline solution including: tri-N-propylamine; arginine; water; and an alkalizing agent selected from glucamine and bis (3-aminopropyl) dodecylamine, where the pH value of the alkaline solution is ≥9.5.

Claims

1. Hair dye comprising: a mixture comprising primary dyes, couplers, at least one alkalizing substance, a buffer substance, an antioxidant substance; at least one oxidizing agent, characterized in that said alkalizing substance is contained in an alkaline solution comprising: tri-N-propylamine; arginine; water; an alkalizing agent selected from glucamine and bis (3-aminopropyl) dodecylamine, where the pH value of said alkaline solution is ≥9.5.

2. Hair dye according to claim 1, characterized in that the pH value of said alkaline solution is 10.5.

3. Hair dye according to claim 1, characterized in that the amount expressed in percentage by weight in relation to the total of tri-N-propylamine in said alkaline solution is greater than 20%.

4. Hair dye according to claim 1, characterized in that the components of said alkaline solution are contained with the following amounts expressed in weight percentage of the total: tri-N-propylamine in a ratio of 40%; arginine in a ratio of 30%; glucamine in a ratio of 5%; water in a ratio of 25%.

5. Hair dye according to claim 1, characterized in that the components of said alkaline solution are contained with the following amounts expressed in weight percentage of the total: tri-N-propylamine in a ratio of 40%; arginine in a ratio of 20%; bis (3-aminopropyl) dodecylamine in a ratio of 5%; water in a ratio of 35%.

6. Hair dye according to claim 1, characterized in that the components of said alkaline solution are contained with the following amounts expressed in weight percentage of the total: tri-N-propylamine in a ratio of 28-32%; arginine in a ratio of 18-22%; glucamine in a ratio of 8-12%; bis (3-aminopropyl) dodecylamine in a ratio of 3-7%; water in a ratio of 33-37%.

7. Hair dye according to claim 6, characterized in that the components of said alkaline solution are contained with the following amounts expressed in weight percentage of the total: tri-N-propylamine in a ratio of 30%; arginine in a ratio of 20%; glucamine in a ratio of 10%; bis (3-aminopropyl) dodecylamine in a ratio of 5%; water in a ratio of 35%.

Description

EXAMPLE 1

[0038] Alkaline solution comprising: [0039] tri-N-propylamine in a ratio of 40%; [0040] arginine in a ratio of 30%; [0041] glucamine in a ratio of 5%; [0042] water in a ratio of 25%.

[0043] Said composition is characterized by a higher performance action in the immediate term, i.e. the first few minutes after application of the dye to the hair, having a high percentage of dominant alkalizing agent, i.e. 40% of tri-N-propylamine. However, as the application time continues, the alkalizing effect tends to decrease, losing part of the synergy with the other components.

EXAMPLE 2

[0044] Alkaline solution comprising: [0045] tri-N-propylamine in a ratio of 40%; [0046] arginine in a ratio of 20%; [0047] bis (3-aminopropyl) dodecylamine in a ratio of 5%; [0048] water in a ratio of 35%.

[0049] The operational tests and dyeing tests conducted directly on samples with this particular alkaline solution confirmed excellent coverage, unexpected silkiness and considerable colorfastness.

[0050] The particular alkalinity obtained for this formulation allows excellent opening of the hair scales, enabling the dye to penetrate into the hair follicle structure where it can oxidize and produce coloring. Indeed, it is known that the fastness/duration of the dye on a head of hair does not depend on the fact that the dye is deposited on the outside of the hair but that coloring develops inside the hair follicle structure.

[0051] In alternative variants attempts were made to reduce the percentage of the dominant alkalizing agent, i.e., tri-N-propylamine, testing alkaline solutions comprising: [0052] tri-N-propylamine in a ratio of 28-32%; [0053] arginine in a ratio of 18-22%; [0054] glucamine in a ratio of 8-12%; [0055] bis (3-aminopropyl) dodecylamine in a ratio of 3-7%; [0056] water in a ratio of 33-37%.

[0057] The chemical-physical characteristics of alkaline solutions thus formulated are expressed in a synergy of alkaline values, where the activity of the OH.sup.− ions is released in different times, i.e., oxidation takes place in steps so as to reach a pH value adequate for the purpose of dyeing the hair but, at the same time, completely tolerated by the skin. Excellent results are obtained specifically with the composition of the following example.

EXAMPLE 3

[0058] Alkaline solution comprising: [0059] tri-N-propylamine in a ratio of 30%; [0060] arginine in a ratio of 20%; [0061] glucamine in a ratio of 10%; [0062] bis (3-aminopropyl) dodecylamine in a ratio of 5%; [0063] water in a ratio of 35%.

[0064] The use of tri-N-propylamine (also called tripropylamine) in the alkaline solution surprisingly allows permanent hair coloring to develop even with a relatively low percentage thereof, without the use of ammonia or ethanolamine (MEA). In fact, it is a highly alkaline substance and bonds optimally, allowing faster migration inside the hair. Moreover, it allows very effective coverage of the hair in suitable times, due to the lightness and simplicity of its molecular composition.