Rubber additives are broadly defined as materials added to high molecular weight rubbers for the purpose of improving rubber processing properties and imparting specific properties to rubber products. According to this definition, rubber auxiliaries do not include reinforcing skeletal materials or plastics, which cover carbon black, light-coloured fillers, mineral oils and other materials that are added to rubber in large quantities. In a narrower sense, rubber additives are materials used in small quantities, typically from one part to several parts. This definition includes mainly organic additives such as vulcanisation accelerators, but of course does not exclude inorganic additives. From the point of view of chemical composition, rubber auxiliary products contain a small amount of inorganic compounds, such as zinc oxide and silica; however, they are mainly organic compounds with complex structures, which are obtained through various synthetic methods.