THE CHEMISTRY OF DYES AND PAINTS

THE CHEMISTRY OF DYES AND PAINTS
ABSTRACT
The Chemistry of Dyes and Paints
          The
existence of man depends on his ability to react to the natural substances that
he is surrounded with and makes use of chemicals of various kinds available to
him to maintain his socio – cultural existence.
          This
process include dyeing in ancient time and making of paints in the present day
of modern technology.
          Paints
are gradually modifying the existence of man. 
In areas of beauty, prevention and preservation of economy.
          Today,
colour is no more limited to the seven primary colours that is, Red, Orange, Yellow, Green,
Blue, Indigo and Violet.  Any desirable
colour can be made out of these seven primary colours.



TABLE OF CONTENT
Title page
Approval page
Dedication
Acknowledgement
Abstract
Table of content
CHAPTER ONE
1.1           
Introduction
1.2           
Historical
Survey of Dyes and Paints
1.3           
Different
Kinds of Dyes and Paints
CHAPTER TWO
SYNTHESIS
2.1           
Mechanism
of Diazotization
2.2           
Coupling
Method
2.3           
Principles
of Formation and Production of Paints
2.4           
Method
of Film Formation
CHAPTER THREE
APPLICATION OF DYES AND PAINTS
3.1           
Methods
of Dyeing
3.2           
Chemical
Forces Responsible for Dyeing
3.3           
Principles
of Dyeing
3.4           
Method
of Painting
3.5           
Defects
in Paints
CHAPTER FOUR
USES OF DYES AND PAINTS
4.1           
Utilization
of Dyes
4.2           
Different
Kinds of Dye and Their Uses
4.3           
Different
Types of Paint and their Uses
4.4           
General
Uses of Paints
4.5           
Discussion
4.6           
Conclusion
REFERENCES



CHAPTER ONE
1.1           
Introduction
Dyes are substances that are used to
colour materials especially fabrics such as wool and cotton.  Dye is either a natural or a synthetic
intensely coloured organic substance having the property of imparting more or
less a permanent colour to other substances. (1)
Dyes can be made from chemicals that
occurs in natural object such as plants, wood, shellfish, rocks, or soils.
Nowadays most modern dyes are coloured substances synthesized from certain
chemical compounds called benzonoid hydrocarbons obtained from either coal tar
or petroleum.
A dye is useful if we can affix it to
the substance that is to be coloured and it must also retain its colour on
prolong exposure to light, water and soap treatment, a property referred to as
fastness of dye. The colour of dye is due to the interaction of visible light
with the electron system of the dye molecules (2).
Paint can be defined as a pigmented
liquid composition which is converted to an opaque solid film after application
as thin layer. A pigment is fine solid particles used in preparing paints and
is essentially insoluble in vehicle whilt. Vehicle is the entire liquid portion
of a paint and it includes pigment binder volati9le solvent.(Ref. 3).    
1.2           
Historical Survey Of Dyes and Paints
Dyes used earliest were natural dye
stuffs derived from plants. These include indigo and alizarin which were
obtained from tintoria and madder roots respectively. With the advent of the
synthetic dye which are far more varied in shades and properties and generally
more brilliant, the production of  the
natural dyes has decreased to a very small portion of the total market. Their
greatest uses now are in the dyeing of leather.
Synthetic dyes are not new, chemists
started the synthetic dyes as far back as 1771 when the first synthetic dyes 2,
4, 6 – trini trophenol was prepared by Woulfe and in 1834 Runge prepared
Rosolic acid by oxidation of crude carboxylic acid. It was William who ushered
in the era of commercial synthetic organic dyes when he discovered mauveine
from aniline in 1856. (3)
The discoveries by Peter Griess, a
German chemist of the diazotization reaction of diazorium compound together
with the elucidation by Kekunle in 1865 of the structure of benzene laid the
basis for the next phase of the development of dye industries.
The product obtained by Griess
contained two nitrogen atoms for the one in the amino group.using old name
(azote) for nitrogen, Griess called these new substance diazo compounds (Ref.
3)
R. Clavel discovered disperse dyes
for the dyeing of acetate fibres and vat dyes containing azo groups were
developed by E. Honold and M.Schnbert in 1921.
reactive dyes procion for cellulose were discovered by I. D. Ratte and W.E.
Stephen in 1956 (Ref. 4).
In 1863 C. Martins synthesized
Bismark Brown III. This dye contains three moles of dirphenylene diamine. In
1870 A Kekule coupled diazotized aniline to phenol thus, preparing the first
hydroxyl azodye. The first synthstic azo dye for wool chrysodine Y (basic
orange) was prepared by H.Caro and O.N. Witt.
Very much
familiar with diazotization, Heinrich Caro who happened to be in England when
Griess was there found out that Rosaline could be diazotized. With youthful
exaggeration Carl Graebe and Lieberman made a more intimate research and they
did not only prepare alizarin but they held nitrogen atoms responsible for the
physical properties of colour. This was in 1968.



TYPICAL DYES MENTIONED

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