Catalyst are the substance that changes the rate of reaction in a chemical reaction while its composition and mass remain unchanged after the reaction. The catalyst which accelerates the reaction is called a positive catalyst (Positive Catalyst), and the slowed down is called a negative catalyst (Negative Catalyst) or a retarder. Additive are large class of important chemical in the production of auxiliary raw materials, they can give a special performance to product, improve use of finished products; and can accelerate the chemical reaction rate, improve product yield; they can save raw materials, improve processing efficiency.
