How pigments differ from dyes?
Pigments, unlike dyes, do not dissolve in binders and solvents. Thus, only pigments are suitable for use in painting materials. However, pigments can be produced from dyes.
What are the relationships between the terms: coloring agents, dyes and pigments?
Coloring agents is a term used collectively for all color-imparting substances. They are divided into insoluble pigments and soluble dyes.
What are micronized pigments and what are their advantages?
The particle size of the micronized pigments is even below 0,4 μm. These pigments have poor coverage, translucent, on the other hand, they reflect harmful ultraviolet rays well, short wave. This is why, micronized pigments are readily used for translucent coatings for wood.
What is the difference between the hiding power and the coloring power of pigments??
The hiding power is a property of the pigments contained in the painting material, covering the difference in shade between the substrate and the coating.
The ability to color, on the other hand, is this, that the pigment in question, mixed with other pigments in the painting material, changes its shade to its own shade.
On what factors depends the covering ability of the coating? Covering capacity depends on:
1) wielkości cząstek pigmentów;
2) postaci pigmentu;
3) różnicy współczynnika załamania światła pomiędzy spoiwem a pigmentem;
4) ilości pigmentu;
5) kontrastu między powłoką a podłożem;
6) grubości warstwy powłoki.
What is the pigment oil number?
The oil number expresses the amount of linseed oil in grams, which it absorbs 100 g of completely anhydrous pigment, until homogeneous, not yet sticky mass. The oil number is a measure of the pigments required for the binder.
What is the relationship between the high oil content of the pigment and the properties of the painting material?
Pigments with a high oil number, hence a high demand for binder, increase the viscosity of painting materials. These, in turn, dry more slowly. Due to the high binder content, Coatings made with such pigments tend to swell more when exposed to water. At the same time, the mechanical strength deteriorates.