Cellulose Acetate Butyrate: Making Coatings and Plastics Better!

Cellulose Acetate Butyrate, abbreviated as CAB, is a mixed fatty acid ester derived from natural renewable cellulose resources and prepared through esterification modification. Its CAS number is 9004-36-8.

Product Properties: The product appears as white to transparent granules or powder, with a density of 1.15–1.22 g/cm³, a melting temperature of approximately 140°C, and a long-term service temperature range of 60–104°C. The molecular structure of CAB contains three active groups: hydroxyl, acetyl, and butyryl. The ratio of these three groups determines the overall performance of the product. As the butyryl content increases, the density decreases, the solubility range expands, and the flexibility and compatibility with resins improve accordingly. As the acetyl content increases, the melting point and tensile strength increase. This structural tunability gives CAB the flexibility to adapt to different application scenarios. In terms of core performance, CAB exhibits excellent moisture resistance, UV aging resistance, cold resistance, high transparency, and electrical insulation properties. It is compatible with a variety of synthetic resins and high-boiling plasticizers. Its tensile strength ranges from 14 to 52 MPa, and its flexural modulus ranges from 621 to 2070 MPa, combining toughness and rigidity. Commercially available products are classified into different grades (e.g., CAB-381-2, CAB-551-0.2) based on butyryl content and viscosity level, meeting the requirements of various processing technologies.

Main Applications: CAB is an indispensable additive in the coating industry, widely used in high-grade automotive paints, motorcycle paints, metallic flash paints, wood coatings, plastic coatings, and printing inks. In automotive metallic paint systems, CAB effectively improves the orientation of aluminum powder pigments, giving the paint film a uniform metallic luster. In addition, CAB enhances the water resistance, flexibility, weatherability, and leveling of the coating film while shortening solvent evaporation time, earning it the reputation of being the "monosodium glutamate" of coating production. In the plastics processing field, CAB can be used to produce highly transparent and weather-resistant plastic sheets, packaging films, as well as injection-molded products such as cable insulation layers, tool handles, and automotive components.

Conclusion: Overall, thanks to its tunable structural parameters and excellent film-forming, compatibility, and weather-resistant properties, cellulose acetate butyrate plays an important role in high-value-added fields such as coatings, plastics processing, and printing inks.