This document discusses types of paint pigments. It begins by defining pigments and their main functions in paint formulations. Pigments are then classified by their origin as either natural or synthetic, and by their chemical structure. The document also distinguishes between organic and inorganic pigments. Specific examples of commonly used pigments are provided for different colors, including red, yellow, blue, green, and white pigments. Inorganic pigments tend to be chemically inert and very lightfast. The most important white pigment is titanium dioxide, while other important colored pigments include iron oxides, chromium compounds, and cadmium and lead pigments.

1.  Imran Laiq
 Roll No. 12
 M.Sc. (Analytical Ch) Part II
 Semester IV (2021 )
 CKT College New Panvel
 Date: 07/06/2021
Types of paint pigments

2. Contents
• Introduction
• Selecting a pigment
• Classification of pigments
• Organic pigments
• Inorganic pigments
• White pigments
• Colored pigments
• References

3. Definition:
Pigments serve three main functions:
the optical function;
a protective function
a reinforcing function
The pigments are used in paint formulation to carry out one or more
of the following tasks:
I. To provide color,
II. To hide substrates and obliterate previous colors ,
III. To improve the strength of the paint film,
IV. To improve the adhesion of the paint film,
V
.To reduce gloss,
vi. To reduce cost,
Introduction

4. Selecting a pigment
a) Hiding power
b) Tinting strength
c) Refractive index
d) Light fastness
e) Particle size and shape

5. Classification of pigments
1. By Their Origin: a- Natural b- Synthetic
2-By the Chemical Structure of the Chromophore :
A- Chromophores with conjugated systems:
carotenoids, anthocyanins, betalains, caramel, synthetic pigments,
and lakes.
B- Metal-coordinated porphyrins: myoglobin, chlorophyll, and their
derivatives.
3- By the Structural Characteristics of the Natural Pigments:
a-Tetrapyrrole derivatives: chlorophylls and heme colors.
b-Isoprenoid derivatives: carotenoids and iridoids.
c-N-heterocyclic compounds :purines, pterins, flavins, phenazines,
phenoxazines and betalains.
d-Benzopyran derivatives:
anthocyanins and other flavonoid pigments. Quinones:
benzoquinone, naphthoquinone, anthraquinone. Melanins.

6. Organic pigments
 Insoluble in the pure form, are known as toner pigments and
those, which require a base, are referred to as lakes.
 Brighter in color, more transparent (lower hiding power),
considerably greater in tinting strength, and poorer in heat and
light-fastness.
A- Red pigments
Toluidine red, barium lithol red and
BON red are the three widely used
organic red pigments.
The toluidine reds are insoluble azo dyes.
It is an azo derivative of B-naphthol
Toluidine red is bright red of
moderate light-fastness, good chemical
resistance and good hiding power.

7. B- Yellow pigments
Insoluble azo class of pigments and they belong
to the four main classes:
Monoarylide yellows
Diarylide yellows
Benzimidiazolone yellows
Heterocyclic yellows
The Hansa yellow is a bright monoarylide
often used in trade sales and emulsion paints.
They have low opacity in paint films and are
soluble in aromatic solvents.

8. C-Bluepigments
Structure of Copper Phthalo cyanine Blu
copper phthalocyanine is the most
common
This is a bright, versatile pigment of
outstanding light fastness.
D- Green pigments
The phthalocyanine greens are
economical and have good light-
fastness.
The excellent stability of these
pigments permits their
use as colorants in all forms of
decorative and industrial coating
systems
Structure of Phthalocyanine Pigments

9. Classification of inorganic pigments
 White pigment : 1)Titanium dioxide
2)Zinc oxide
3)Antimony oxide
4)White lead
5)Lead sulfate
 Colored Pigemts :1)Iron oxide
2)Red lead
3)Cadmium red
4)Lead silicochromate
5)Lead chromates
6)Zinc chromates
7)Cadmium yellow
8)Calcium plumbate
9)Chromium oxide
10) Prussian blue
11 )Ultramarine blue

10. 1)Whitepigments
 Also used in a substantial fraction of other pigmented paints to
give lighter colors.
 Presently, the most important white pigment used in paints is
titanium dioxide.
 Lithopone is a mixed zinc sulfide-barium sulfate pigment
available in two types; one containing 30 % zinc sulfide and
another containing 60 % zinc sulfide.
 After TiO2, zinc sulfide is the strongest white pigment due to its
brilliant white color, extremely fine texture and relative cheaper
cost.

11. 2) Coloredpigments
 Chemically inert, very light-fast products.
A- inorganic Red pigments:
 Red iron oxide (Fe2O3) is an inorganic pigment of either natural
or synthetic origin.
 Synthetic pigment is made by heating iron sulfate with quicklime
in a furnace.
 Indian red is a naturally occurring mineral whose ferric oxide
content may vary from 80 to 95%
 Red lead (Pb3O4) is a brilliant red-orange colored synthetic
inorganic pigment used mainly as a protective priming coat for
steel work rather than a coloring pigment in paints.

12. B-Yellowand orange pigments
 Yellow Iron Oxide, FeO(OH), lead chromates, PbCrO4, zinc
chromates, ZnCrO4 and cadmium yellow, CdS belong to standard
pigments among the yellow pigments.
 Yellow iron oxides give opaque films with good hiding, chemical
and solvent resistance is excellent.
C- Blue and greenpigments
 Ultramarine blue is a complex of sodium aluminum silicate
and sulfide
 The color of the pigment is attributed to the presence of
sulfur.
 Ultramarine is widely used as bluing in laundering to
neutralize the yellowish tone in cotton and linen fabrics.
 Prussian blue, KFe(Fe(CN)6), is an intense reddish shade
blue pigment with fairly good properties.

13. REFERENCES
• http://faculty.kfupm.edu.sa/CHEM/belali/CHEM%2
0456/Chapter%207/CHAPTER%207_PAINTS,%20
PIGMENTS,%20AND%20INDUSTRIAL%20
• http://www.freedoniagroup.com/brochure/22xx/2232
smwe.pdf
• http://nzic.org.nz/ChemProcesses/polymers/10D.pdf
• https://mail.google.com/mail/u/0/?pli=1#inbox/14cf5
9ec65254863?projector=1