Hair colouring

A hair coloring is carried out to give different shades of color to the hair. A hair coloring is usually colorfast even after repeated washing my hair with surfactant-containing detergents.

Changes in color of the hair can be achieved by bleaching or hair dye.

The hair coloring can be in terms of the number of washes after the dyeing, and the respective stability of the color change in a temporary, semi-permanent and permanent dyes classified. A temporary hair color disappears after the first washing with a shampoo. It is based on a physical adhesion of a dye. A semi-permanent hair color lasts from about two to ten washes. A permanent stain withstands more than ten washes. This cosmetic dyes are chemically linked to specific amino acids in the hair or oxidized during bleaching pigments of hair.

It is estimated that about 40 % of adult women use hair dye in the industrialized countries.

History

Already 3000-4000 years ago, hair dyeing with natural dyes henna, indigo, and later with Rastik was common. The Romans colored their hair with lead ridges that were dipped in vinegar. It was made ​​of the reaction with the amino acid cysteine ​​in hair keratin blonde to dark colors.

1900 Before the colorants were often made ​​of inorganic silver nitrate solutions or other metal salts, mixed with pyrogallol solution. The silver ions react with the amino acid cysteine ​​in hair. This shades between blonde and black could be set.

The first long-lasting wear azo dye for hair was developed in 1883. A hair dye composition for human hair from 1895 and consisted of 1,4- phenylenediamine, p- amidophenol and diamido and was brought under the name " Chenie 's Hair Color Fo " in the trade; even back then highlighted the potential risk of skin irritation during the dyeing process.

Temporary hair coloring

The temporary hair coloring is used to slightly modify the natural hair color. This stain can be completely removed after a single shampooing again. For hair dyeing azo, triphenylmethane or anthraquinone dyes are used. These are sold as a temporary dye aqueous alcoholic solutions.

In conjunction with hairspray even very small gold or silver luster pigments or even fluorescent materials can be brought into the hair. Also eyelashes and Augenbrauenfärbemittel belong to the temporary hair dyes. Suitable colorants are used as carbon black and ocher.

Semi-permanent hair coloring

For shading using semi-permanent dyes. They have a high affinity for the keratin of the hair, the binding of the dyes are physically. As synthetic hair dyes Nitrophenyldiamine, azo and quinone dyes are used in conjunction with organic solubilizers such as glycol or polypropylene.

The natural semi-permanent hair dye henna, Reng, chamomile, wood, bark extracts and Rastik have become less important.

Leaves and stems of the plant Lawsonia alba Lam. (or inermis L. L. ) as the color component of 2 -oxy- 1, 4 - naphthoquinone. The extraction of the dye via drying of leaves and stems, Verpulverung same, solution of the dye with hot water and then up to the hair. The henna dye dark hair is a chestnut -colored tint.

Occurs in leaves of the indigo plant. It is used together with henna. Henna can be between auburn hues - black reach, depending on the mixing ratio.

The flowers dye apigenin ( 5,7,4 '- Trioxoflavon ) of chamomile causes a yellowing of the hair.

Is a mixture of pyrogallol and iron, copper salts. Pyrogallol was obtained by roasting of galls. The hair is dyed jet black of Rastik.

Permanent hair coloring

The permanent hair coloring is by far the most important method to color hair. A permanent hair coloring is practically not removable, but the hair grows about 1 cm a month, so that the hair colors about every month must be replaced if you want to keep a uniform hair coloring.

In some sensitive individuals, it comes in two-component hair colorings skin irritation. The hair can be damaged, thereby gloss, comb, grip the hair be adversely affected by hair coloring, perming or frequent washing. These disadvantages are trying to weaken the company by cationic surfactants and the addition of creatine. More recently, alkylguanidine compounds in the treatment or post-treatment are recommended.

Even quite mild -component enzyme-based hair colors have been developed. However, such hair dyes must be protected to the hair prior to the application well before atmospheric oxygen. The advantage of these dyes is that they are milder than two- dye, the disadvantage, however, lies in a weaker staining.

Since hydrogen peroxide as oxidant damages the hair fiber and can cause skin irritation, companies try to replace this compound by use of dicarbonyl and amino compounds.

Two-component hair coloring

The permanent hair color ( oxidation hair coloring ) are oxidation bases, that is easily oxidized aromatic compounds (for example, phenylene diamine, toluene diamine, aminophenol ) together with Nuancierern ( substances that the hue change something ) in the presence of hydrogen peroxide and ammonia, emulsifiers and water on the hair brought. The dye now wander in the - swollen by the alkaline medium - hair inside, where they are oxidized to complex dyes, they combine chemically with the keratin. Only by the oxidation of the dye base of the hydrogen peroxide is formed by the dye.

A commercially available, permanent hair dye consists of two components: a tube with these oxidation bases, Nuancierern and a vial of hydrogen peroxide.

In addition to the dye base containing a hair coloring agent or thickening agent, for example fatty alcohols and lanolin, so that the mixture is creamy. Thus, the oxidation bases are not oxidized prematurely exposed to air, a coloring agent also contains antioxidants, such as sodium sulfite or sodium or ascorbic acid. Further, in the color paste, some ammonia solution (about 1 % strength or monoethanolamine ) and some surfactant is contained.

Can oxidation bases are p-, o- phenylenediamine, o-, p -dihydroxybenzene, and o-, p-aminophenol, or derivatives of these compounds. Depending on the composition of aromatic compounds gives different shades.

Common oxidation bases are, for example, 2,5-diaminotoluene, 2,3- diaminotoluene, 2 -aminophenol and 4-aminophenol. As Nuancierer serve disubstituted aromatics in meta position (m- dihydroxybenzene, m-aminophenol, m-phenylenediamine ).

Through the Cosmetics Regulations of 1977 and 1982, 1,4- phenylenediamine, 2,4- toluene diamine and 2,4- diaminoanisole banned because they are suspected of carcinogenic effect. Even at 2.4 - and 2.4 - diaminoanisole diaminotoluol carcinogenic effects have been demonstrated.

Banned in hair dyes are the following compounds: 1,2-diaminobenzene, 1,4- diaminobenzene, 2,4- diaminoanisole, 2,5- diaminoanisole, 2,4 -diaminotoluene, 2-amino- 4-nitrophenol, 2 -amino- 5-nitrophenol. The permitted colors may be available only in the permitted doses in the colorant.

The prohibition of chemical ingredients in hair dyes have been handled differently from country to country prior to 1990. Such was the 1,4- phenylenediamine ( a compound for the manufacture of black shades) Hair dye substance in many countries an important (eg in the U.S.), in Germany there were very early (1906 ) a prohibition against this connection.

The free oxidation bases may not be more than 6% in the hair dye. Hydroquinone may be used for 2% to 5% resorcinol and alpha -naphthol only to 0.5%.

Physical color change

This method of color change is semi-permanent, it does not change the natural pigment, one uses so-called direct dyes. Since the color can not penetrate into the cortex of the hair, the colors stored only on the cuticle. Therefore, this type holds the color change only up to about a maximum of twelve washes. The pigments in the so-called direct dyes are cationic active. By the electrically positive charge (cationic ), the color may be deposited on the negatively charged ( anionic ) hair. The more porous the hair is, the more intense the color put on at this point and can thus penetrate further into the cortex. Permanent or whitening results are, however, not be achieved with this method.

In addition, you can include plants colors to the semi-permanent color changes. In the vegetable dye eliminated largely chemical additives, the shelf life on the hair is therefore limited. Since there is no " coloring" in the proper sense, Heller colorations are not possible. With vegetable dye dyed hair to be dyed with permanent hair color is inadvisable.

• Carrier mass: alcohol;

• Carrier mass: Alcohol foam;

• Carrier mass: PVP / VA copolymers, care substances;

• Carrier mass: cationic conditioning agents;

• Carrier mass: cationic gel on care fabric base;

Chemical color change

For a permanent color change to the barber, two different methods: the bleaching and oxidative dyeing.

A product which is required for both operations, the hydrogen peroxide (formula: H2O2). Due to the addition of H2O2 occurs in the hair an oxidative process, oxygen is attached, and changes the color effect of the pigments.

Since the chemical color change, except for the bleaching is additive, so dyes are attached, a specific staining of this chemically treated hair is no longer possible.

H2O2 is used due to the reactivity of oxygen to hair coloring can. The hairdresser, the following concentrations of H2O2 are available:

For a bleaching is the most suitable one Peroxidstärke to 6 %. A common misconception says that 1.9 %, 3% or 4 % would not lighten enough. This myth has been disproved by various tests. Also, a solution of 1.9% H2O2 is quite able to gently lighten a dark foundation. The only downside is that it takes longer than 6-12 %. The result is a clear blonde shade without much gold content.

Ingredients

These are undeveloped pigments that can penetrate very well into the hair due to their small molecular size and thus achieve a uniform cortex staining. Only the addition of H2O2 oxidative process is triggered. Through the active oxygen colorless dye precursor to develop the visible pigment. Since these pigments combine creates a kind of " cage effect " and so, the pigments can hold in the cortex of the hair. Only if a hair color contains color precursors, white hair can be covered at 100%. There are basically only two types of dye precursors, however, these are both in each tone in different amounts. The concentration of the dye precursors and couplers results in different oxidative hair dyes

• Group 1 = dye precursors
• Group 2 = shade modifiers ( color couplers ) Sometimes Directpulling / Temporary color pigments are present in oxidative colors

Color precursors are usually PPD, PTD or Recorsin. These have a brown design and give the hair color, the tonal depth. ( How light or dark it is )

Shading agents are partly developed or anoxydierte color formers which give a color a certain color direction / shading.

All dyes are made ​​of various basic chemicals and preserved.

In all hair colors as an alkalizing agent ammonia water or similar substances is used ( toluene, diamines, resorcinol and many others). This quantity and pH being different. They have the property to volatilize ( abzugasen ), so the concentration decreases with the length of exposure time. Alkalis are essential for hair dyeing, as these swell the hair and make the hair thus more receptive. Only then may the color to penetrate the cortex.

These include solvents such as isopropanol or ethanol ... cream ( so-called zero masses) or gels are the most common carrier masses in the color cosmetics. They usually consist of fat-like, cationic set basic substances that act caring.

Promote the penetration of all active substances, since they reduce the surface tension of moisture, and ensure an even distribution on the hair.

Ensure a uniform degradation of the agents, that is, they ensure that after mixing the dye composition of the workflow not vonstattengeht explosively. Keep the pH constant.

Keep the color stable in the package and reduce the sensitivity to oxidation of the dyes. Although these can not prevent for example, red dyes are only about 70% of responsive after half a year.

Superimpose the strong smell especially in alkalis.

Expiration

After mixing the color with H2O2 results in the following sequence:

Alkalizing agents (ammonia, usually MEA with high pH - value between 9 and 11) to swell to the hair and neutralize the stabilization of H2O2. This frees active oxygen. This lightens, depending on the concentration, the natural pigment. The carrier mass ensures that the hair color will stick and not " wanders". Improve the wetting agent, the capacity of the hair, buffer substances (such as sal ) govern the entire process.

From the addition of at least 6% H2O2 natural pigment is first brightened while the dye precursors and couplers are brought into the hair. This now superimpose the brighter natural pigment, which, depending on results after a certain contact on the concentration of H2O2, the desired result.

Indispensable for the hairdresser is the accurate determination of the natural clay of the customer to determine the right H2O2 concentration. Also, the mixing ratio of the components ( Farbe/H2O2 ) plays a role in achieving the desired color target.

It is important to note that in lightening the natural hair an undertone / Blondiertabelle of the hair is visible. This must be neutralized or amplified according as desired.

Untertontabelle:

This table is visible at: cloudy, bleaches and colorants with 6 %, 9% and 12%. Thus, it is also to explain that selbstblondierte or even dyed hair usually have an orange or gold approach, as it was, worked there usually wrong with excessive oxidant or too short a time. Only a professional can add the coloration corresponding " opposite colors " and determine the correct exposure time. Opposite colors are: Orange - Blue, Gold - Purple, Red - Green,

The non- consideration of the Blondiertabelle / Untertontabelle also leads to a greenish tint in her hair. This happens when the lightened / bleached hair will dark colored. Here you have in advance a " Rückpigmentierung " take place. This means that the hair gets pigments, which have been removed at the lightening / whitened. Most are working in advance with a copper -gold or copper - red tint.

Bleach

For a permanent color change to the barber is still the bleaching available. When bleaching, hydrogen peroxide is used in concentrations between 1.9 to a maximum of 12 %; at higher concentrations of hydrogen peroxide to the hair structure changed. More than 6% of oxidant may not be applied to the skin.

The hair is composed of several peptide chains, the fundamental building blocks are individual amino acids. The amino acids in peptides containing functional groups that pass through interactions ( hydrogen bonds ) with other amino acids and their functional groups and certain salts to the hair strength and elasticity. When bleaching the color pigment melanin is released, many hydrogen bonds lose their grip. There are two different melanins:

The respective pigments, which lend the hair color, are thereby destroyed by oxidation, the hair is blond.

Since the bleaching, not only destroys the color pigments, but also a lot of " putty " of the cortex, a bleaching is carried out only by qualified personnel without major damage. Otherwise, the improper implementation of a bleaching even lead to hair loss. In an incorrectly performed Blondierung a hairdresser can make damages.

In bleaching powder are ammonia (opens the cuticle ) and persulfate ( Aufhellbeschleuniger ) contain, which can swell the hair and thus allow the effect of H2O2 on the pigments. The differences in the speed of lightening lie exclusively in the exposure or in the heat supply means Climazon or similar. The heat addition is not recommended, since heat can promote more hair and scalp damage. Much more important for a maximum Aufhellergebnis are two factors:

As a rule the bleaching is washed with an acidic shampoo to prepare the natural pH of the hair again. After whitening with Blondierpräparaten a deep conditioner or hair mask must be made. Most suitable proteinaceous or ceramidhaltige products that can repair the damage of the hair part again.

Saurer deduction

The sour deduction or the reductive color print is a variant of the correction of an oxidative color result with freshly dyed hair. This applies to the colorants, tints intensive and permanent hair color. Here unsolidified and consolidated dye molecules are released from the hair by means of a acidified preparation, or the oxidized dye molecules chemically reduced by elimination of oxygen. There are several ways the reductive process in the hair to make. The home agent is easiest to use of ascorbic acid ( vitamin C). For the vitamin C powder is dissolved in water and left for up to 30 minutes in the hair. The artificial pigments are dissolved out of the hair. The long, thorough rinsing is very important. This application also helps against "green" hair after swimming in chlorinated water.

In an industrial color proof usually an alkaline reducing agent is developed by means of an acidic solution. The pH of the final mixture is strongly acidic.

The acidic color print does not affect the substantive pigments ( foam tints, henna colors, herbal hair colors ).

The acidic color proof is used as an alternative to alkaline extraction ( bleaching ), as it is gentler to mitigate such undesired shade or too dark color results. However, this is the best possible shortly after a hair dye, then the dye molecules as part are not fully solidified and are easier to solve.

Criticism

Chemical hair dyes are highly effective chemicals that can cause side effects such as skin irritation. Reaches the colorant in the application to the eye, it may be damaged. To reduce hazards to humans on a minimum measure, and prevent potential damage claims against manufacturers of animal tests are still made ​​. The environment is polluted in the production. Often make natural dyes a more compatible alternative dar.