Softeners can be divided into chemical softeners and physical softeners. Chemical softeners can cut off the molecular chain of a few rubber hydrocarbons and are a weak peptizer. Physical softeners mainly weaken the intermolecular forces of rubber hydrocarbons and act as lubricants. More commonly used in the industry are physical softeners, which are mainly classified into the following categories according to their sources.
1 Petroleum softeners are mainly complex mixtures of paraffins, naphthenes, aromatics and a small amount of asphalt materials, nitrogen-containing organic bases, and the like.
2 coal tar softeners include coal tar, coumarone resin and coal tar pitch.
3 Fatty oil softeners are natural oils and their derivatives, such as vegetable oils, fatty acids and ointments.
4 Pine oil softener is a product obtained from turpentine, such as pine tar, rosin, tall oil, wood asphalt and the like.