*5.2.1.5 Titanium dioxide*

It consist of TiFeO3, TiO2 (iliminite+rutile). It is widely used in paints, in paper and textiles.

#### **Properties:**

*5.2.1 White pigments*

**Properties:**

• Easily applied

• Toxic in nature

**Properties:**

*5.2.1.3 Zinc oxide (ZnO)*

**Properties:**

*5.2.1.4 Lithopone*

**Properties:**

• Good hiding power

industry.

**142**

• High covering power

• Soluble in alkali and paints

is used in the manufacture of paints.

protects us from UV, prevents chalking.

• Extremely fine and cheap pigment

• Brilliantly white having excellent texture

• More durable in combination with white lead

*5.2.1.2 Sublimed white lead (basic sulphate)*

• High specific gravity and refractive index

• Slow chalking out of the film producing a rough surface

• Causes no discolouration even in contact with CO2 gas

white pigments can be summarised as follows;

*Dyes and Pigments - Novel Applications and Waste Treatment*

• Yellows badly on exposure to the atmosphere

*5.2.1.1 White lead {2PbCO3.Pb (OH)2}*

is used in the manufacture of paints.

They are of various types. The composition, properties and applications of some

The composition of the Lead Carbonate is 68.9% and Lead Hydroxide is 31.1%. It

The composition of Lead Sulphate is 75%, Lead Oxide 20% and zinc oxide 5%. It

The composition of Zinc Oxide is 100%. It is opaque to UV light and thus

The composition of lithopone is 28.30% zinc oxide and 72.70% barium sulphate. It is widely used for the cold water paints, traffic plants, floor covering and oilcloth


#### *5.2.2 Blue pigments*

Ultramarine Blue and Cobalt Blues are the most widely used blue pigments. The composition, properties and applications of these can be summarised as follows:

#### *5.2.2.1 Ultramarine blue*

There are three varieties of ultramarine namely blue, white and green. It is used as bluing in laundering to neutralise the yellowish tone in cotton and linen fabrics. White Ultramarine Blue: Na5Al3Si3SO12, Green Ultramarine Blue: Na5Al3Si2S2O12, Blue Ultramarine Blue: Na5Al3Si2S3O12.

#### **Properties:**


### *5.2.2.2 Cobalt blues*

The composition of cobalt blues is 30–35% Co3O4 and 65–70% Al2O3. It is used in the manufacture of blue paints, inks, carbon paper and carbon ribbons. **Properties:**
