What are TAC polarizing lenses

Definition of TAC polarizing lens

TAC sunglasses are widely used in China, so what is TAC? The TAC lens is made of three cellulose acetate. TAC (three cellulose acetate film) is an optical thin film used to manufacture polarizer. It is generally believed that cellulose acetate with esterification degree above 2.7 is cellulose triacetate (TCA). Some people also think that cellulose triacetate means that the acetic acid content is not less than 59% (DS 2.75), but most of the cellulose triacetate acetic acid content is higher than 61% (DS 2.85).

What are TAC polarizing lenses

The common technique is to esterify acetic acid with acetic anhydride in acetic acid as solvent, using acidic catalyst. The temperature is not high and the time is not very long, but it has to be pretreated. 

What are TAC polarizing lenses

With the in-depth study and understanding of the properties of cellulose triacetate, the requirements for its quality indicators are getting higher and stricter, and the requirements for equipment are getting higher and higher. How to get the products with specified degree of substitution and uniform degree of substitution is a problem that people have been concerned about. Therefore, the key to the preparation and production technology and technological difficulties of cellulose acetate is the key.