Cellulose acetate butyrate

Cellulose acetate butyrate (CAS 9004-36-8), commonly known as CAB, is a mixed cellulose ester produced by reacting cellulose with acetic and butyric acids. Compared to standard cellulose acetate, CAB offers lower moisture absorption.

It provides improved compatibility with a broader range of plasticizers and resins, which are factors that directly influence grade selection for formulators. It functions primarily as a film-forming binder and rheology modifier.

CAB acts as a flow-control agent across coatings, plastics, and printing applications. In industrial and automotive coatings, it controls metallic flake orientation and prevents pigment settling during application, improving finish consistency.

Thermoplastic compounders incorporate it into transparent and tinted plastic parts where low haze and UV stability are priorities. In printing inks, CAB contributes to adhesion, gloss, and controlled viscosity across solvent-based formulations.

Adhesive and sealant manufacturers use it as a modifier to adjust tack and film flexibility without compromising bond strength. CAB is supplied as a free-flowing white to off-white powder or granule, with particle size varying by grade.

Commercial grades are differentiated by butyrate content, viscosity, and acetyl-to-butyryl ratio. These are key parameters buyers specify to match processing conditions. Technical and industrial grades are standard for most industrial uses.

Food-contact compliance varies by specific grade and regional regulation. This versatile polymer remains a staple for manufacturers requiring high-performance film properties and reliable chemical stability in demanding environments.