power point on Hair dye

1. BY
MANISH KUMAR SINGH

2. HAIR DYE OR HAIR COLORING IS THE
PRACTICE OF CHANGING THE HAIR COLOR.
THE MAIN REASON FOR THIS ARE
COSMETIC : TO COVER GRAY HAIRS OR TO
CHANGE THE COLOR OF HAIR WHICH IS
REGARDED AS MORE FASHIONABLE OR
DESIRABLE IN TODAYS WORLD.

3. HISTORY
HAIR COLOR IS THE MATTER OF
CHEMISTRY. THE FIRST SAFE
COMMERCIAL HAIR COLOR WAS
CREATED IN 1909 BY FRENCH
CHEMIST EUGENE SCHULLER, USING
THE CHEMICAL
PARAPHENYLENEDIAMINE (PPD).

4. HAIR IS MAINLY KERATIN, THE SAME PROTEIN
FOUND IN SKIN AND FINGERNAILS. THE NATURAL
COLOR OF HAIR DEPENDS ON THE RATIO AND
QUANTITIES OF TWO OTHER PROTEINS,
EUMELANIN AND PHAEOMELANIN.
EUMELANIN IS RESPONSIBLE FOR BROWN TO
BLACK HAIR SHADES WHILE PHAEOMELANIN IS
RESPONSIBLE FOR GOLDEN BLOND, GINGER AND
RED COLOR.
THE ABSENCE OF EITHER TYPE OF MELANIN
PRODUCES WHITE / GREY HAIR.

6. People have been coloring their hairs for
thousands of year using plant and minerals.
Some of these natural agents contain
pigments ( e.g. : Henna, black walnut shells )
and other contain natural bleaching agents
like vinegar.
Natural pigments generally works by coating
the hair shaft with color but they aren’t more
gentle than modern formulations.

7. Depending upon the deposition of
various Dyes for suitable time limit, the
dyes are classified into four categories.
They are :

8. In order to deposit permanent hair dye, the
outer layer of hair shaft i.e. Cuticle must be
opened. Once the Cuticle is opened, the dye
react with the inner portion of the hair i.e.
Cortex to deposit or remove the color. Most
permanent hair dyes use a two-step process,
which first removes the original color of the
hair and then deposits a new color.

9. Ammonia is the alkaline chemical that open the
cuticle and allows the hair color to penetrate the
Cortex of the hair. It also acts as a catalyst when the
permanent hair color comes together with the
peroxide.
Peroxide is used as a developer or oxidizing agent.
The developer removes pre-existing color. Peroxide
breaks chemical bonds in hair, releasing sulfur, which
accounts for the characterstic odor of hair color. As
the melanin is decolorized, a new permanent color is
bounded to the hair cortex. Various types of alcohols
and conditioners may also be present in hair dye. The
conditioners close the cuticle after coloring to seal in
and protect the new color.

10. Demi-permanent hair dye are those which
contains an alkaline agent other than
ammonia (e.g. Ethanolamine, Sodium
Carbonate etc. ) and always employed with a
developer, the concentration of hydrogen
peroxide in that developer may be lower than
used with a permanent hair dye.
Demi-permanent are much more effective at
covering Grey Hair than Semi-permanent dye
but less than permanent hair dye .

11. Semi-permanent hair dye may deposit acidic
dye onto the hair shaft or may consists of
small pigment molecules that can slip inside
the hair shaft, using a small amount of
peroxide.
In some cases, a collection of several colorant
molecules enter the hair to form a larger
complex inside the hair shaft. Generally these
products doesn’t contain ammonia and if
contain then in very negligible amount.

12. This dye is available in various forms including
shampoos, gels, sprays and foams. Temporary
hair dye is typically brighter and more vibrant
than Semi-permanent and Permanent hair
dye.
The pigment molecules in temporary hair dye
are large and can’t penetrate the Cuticle layer.
The color particles remain adsorbed to the
hair shaft and are easily removed with a single
shampooing.

13. 1.) The first step shows the oxidation of p-
phenylenediamine to the Quinonediimine
i.e. C6H4(NH)2 .

14. 2.) The second step involves the attack of
this Quinonediimine on the coupler. This
reaction is Electrophilic aromatic
substitution.

15. 3.) In third and final step, the product form
the Quinonediimine coupler reaction which
oxidizes to the final hair dye.
It was believed that the dye forms in the
above reaction bonds to hair permanently
because it produces a larger dye molecule,
which is locked inside the hair.

16. Hair dye or hair coloring involves the use
of Chemicals that are capable of
removing, replacing or covering up
pigments naturally found inside the hair
shaft. Use of these Chemicals can result
in a range of adverse effects including
temporary skin irritation or allergy, hair
breakage, skin discoloration etc.