Eastman Cellulose Esters are bio-based polymers that are used as film formers, resin modifiers, and additives to formulate high performance products in a variety of industries. Improvements to formulations include reduce drying time, improve leveling, increase gloss, improve UV stability, and optimized pigment orientation in protective coatings and printing inks. These polymers vary in ester composition, hydroxyl content, and molecular weight. Ester composition and hydroxyl content effect solubility, flexibility, and reactivity. Molecular weight determines viscosity, solids used, and toughness . Choosing the correct grade for your application starts with selecting an ester type.
Cellulose Acetate (CA): These are the hardest and most durable of the Eastman Cellulose esters. They are excellent for forming protective lacquers that require solvent and grease resistance. They are also used to cast membranes for filtration applications. The compatibility of these products is limited and they are only soluble in strong solvents like acetone. Selection is based on molecular weight and viscosity.
Cellulose Acetate Butyrate (CAB): These are the most versatile of the Eastman Cellulose Esters and are commonly used in coating and ink formulations in a variety of industries. CAB's offer better solubility, resin compatibility, and flexibility than cellulose acetate. There are a wide variety of grades available that rage in butyrl content, hydroxyl content, and molecular weight. Selection of a CAB should be based on the solvents being used, the durability / flexibility requirements of the application, and molecular weight / viscosity.
Cellulose Acetate Propionate (CAP): These esters are an intermediate between CA and CAB. They resemble CA in their performance but also offer the improved solubility and compatibility of a CAB. CAPs are slightly harder than CABs and virtually odor free. They are often used in applications requiring high block and print resistance or if low odor is needed. Selection is based on solubility and molecular weight.
CAB-553-0.4 is a low molecular weight cellulose acetate butyrate polymer with high butyrate content and hyroxyl functionality. It is a film former used in coatings and inks that require alcohol solubility.