PVBA, also known as polyvinyl butyral acetal, has the following chemical properties: density of 1.07 grams/cubic meter, refractive index of 1.488 (at 20 degrees Celsius), water absorption rate less than 4%, softening temperature of 60~65 degrees Celsius. It is soluble in methanol, butanol, acetone, methyl ethyl ketone, cyclohexanone, dichloromethane, chloroform, methyl acetate, ethyl acetate, butyl acetate, etc. It possesses excellent flexibility and flexibility.