Hair dye

power point on Hair dye

1. TOPIC : HAIR DYE 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. MEANING OF HAIR DYE

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. What is HAIR AND NATURAL HAIR COLOR ? 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.

5. NATURAL HAIR COLOURANTS 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.

6. TYPES OF HAIR DYE Depending upon the deposition of various Dyes for suitable time limit, the dyes are classified into four categories. They are : 1.) PERMANENT HAIR DYE 2.) DEMI-PERMANENT HAIR DYE 3.) SEMI-PERMANENT HAIR DYE 4.) TEMPORARY HAIR DYE

7. PERMANENT HAIR DYE 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.

8. 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.

9. DEMI-PERMANENT HAIR DYE 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 .

10. SEMI-PERMANENT HAIR DYE 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.

11. TEMPORARY HAIR DYE 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.

12. REACTIONS INVOLVED IN permanent HAIR DYE PROCESS 1.) The first step shows the oxidation of p- phenylenediamine to the Quinonediimine i.e. C 6 H 4 (NH) 2 .

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

14. 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.

15. ADVERSE EFFECT 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.