Paints And Pigments Flashcards
What does a colloid consist of?
Eg paint
Tiny particles (solid, liquid or gas) suspended in a liquid. Colloids don't separate because the droplets are too small.
Describe the 3 bits that make up paint
Pigment - colour
Binding medium - liquid carrying pigment
Solvent - thins paint so it will spread
Describe what happens as emulsion paint dries on walls.
The solvent (water) evaporates leaving behind a thin layer of binding medium (a polymer) and pigment.
Why are emulsion paints good for walls?
Fast drying, no harmful fumes.
What are traditional oil paints made up of?
Pigment
Binding material - oil
Solvent - organic compound that will dissolve oil
What are the properties of oil paints and what are they used for?
They are glossy, waterproof, hard wearing but have toxic fumes
Used for outside doors + metalwork.
How do oil paints dry?
Solvent evaporates
Then oil oxidised by oxygen in air.
Takes longer
