Shellac, a versatile biopolymer for coatings

 
Shellac, the only commercially used insect resin fits perfectly into the concept of GREEN Chemistry and renewable biodegradable natural resins and binders for coatings. Shellac is an excellent filmformer and has a very good adhesion on many surfaces.High gloss, a good surface hardness and an excellent UV resistance are important properties of this natural polymer. Shellac films are also resistant against hydrocarbons..A very low water vapour and oxygen permeability as well as a good compatibility with other polymers and additives make shellac an interesting binder and coating resin. It can be applied from organic solvents or aqueous alkaline solutions. It is a foodgrade polymer ( E 904 in Europe) and approved for the coating of children's toys. By utililizing the reactive groups of Shellac combinations with other natural or synthetic polymers are possible. Also these groups can be used for crosslinking Shellac or by an esterification to modify filmproperties.