About This Product
This polyvinyl acetal resin (CAS 252364-22-0) carries both formal and acetal groups on a polyvinyl alcohol backbone. It is a white or slightly yellow powder with a density of 1.20 g/cm³, a Vicat softening point of 122 °C and water absorption of no more than 1.2% over 24 hours at 20 °C. Formaldehyde content is 8–14%, hydroxyl content is at most 3%, and the resin dissolves in ethanol, butanol, toluene, cyclohexanone and ethyl acetate. It is used mainly in abrasion-resistant, high-strength enamelled wire coatings and in adhesives for metal, wood, rubber and glass laminates. It also forms the middle layer of laminated plastics and serves as a base for foamed plastics that need high impact strength and a high compressive modulus. The specification prints the degree of formaldehyde (70–83%) and a viscosity of 6–20 s on one line without a test method; confirm that the first figure is the degree of formalisation and how the viscosity is measured. The basis of the formaldehyde content is not given, and formaldehyde itself is classified as a carcinogen, so ask for the free formaldehyde content and the safety data sheet. Packing and test methods are confirmed on enquiry.
