These are chemicals with particular effects, relating either to the manufacturing process or the function of the product. This group comprises:
- Coupling agents
These contain functional groups (eg silanes) that have the ability to create bonds between organic and inorganic substances. For example, they can link silicic acid to a polymer in order to increase modulus of elasticity and tensile strength. The recommended dosage is about 10% in relation to the light-colored filler.