Because they are water-white, nonyellowing, tack-free materials, Eastman cellulose esters are useful alone or in combination with other resins as a film former in solventborne lacquers and lacquer emulsions for natural and synthetic leather topcoats in applications such as automotive upholstery, footwear, handbags, and furniture. These topcoats containing cellulose esters are tough and have good resistance to abrasion and plasticizer migration. Eastman cellulose esters can contribute slip and good "hand feel” to topcoats of various thicknesses over fine or less expensive leathers. Cellulose esters remain stable and will not degrade or yellow in the presence of the amine accelerators found in polyurethane shoe soles and polyurethane upholstery foam. On contact with vinyl, cellulose esters will not extract plasticizers. Compared with other cellulosic film formers, Eastman cellulose esters have excellent light stability; thus they can be used over white or other light-colored base coats.
CAB 381-2 is a good starting point for leather topcoats (solvent or emulsion). It can provide good resistance to abrasion and plasticizer migration, contributes good slip and hand feel, should not yellow in the presence of amine stabilizers used in polyurethane shoe soles and foam upholstery; plus, it has excellent light stability with nonyellowing characteristics. CAB 381-20 may be mixed with CAB 381-2, which can increase solution viscosity and coating strength. CAB 500-5 has a higher butyryl content than CAB 381-2. This can aid formulation solubility and compatibility as well as increase the flexibility of the final coating.
For synthetic leather, CAB 381-0.5 for the wet process will produce embossed images with high definition and antiblocking with good flow and levelling. Solus 2100 or Solus 2300, in combination with a high-modulus polyurethane resin for the dry process, improve tinting strength due to good wetting properties and compatibility.