MULTI-PURPOSE CHITOSAN-BASED MATERIALS AND PROCESS FOR APPLYING THE SAME IN PRESERVATION OF DOCUMENTARY HERITAGE ON PAPER CARRIER

摘要

The invention relates to chitosan-based functional materials and to a method for applying the same on paper support, intended to be used in the field of preservation-restoration of documentary heritage. According to the invention, the materials are chitosan derivatives obtained by treating chitosan, depending on the molecular mass, with an alkyl-aldehyde with a C8-C12 alkyl chain, with monochloroacetic acid in alkaline medium, possibly with a quaternary ammonium salt. The method, as claimed by the invention, consists in applying 2...3 successive layers of carboxymethyl-chitosan or quaternary chitosan, in controlled amounts, over which the same amount of alkyl-chitosan is uniformly applied with a semi-automatic applicator which achieves a controlled application of the polymer amount taken over by surface unit and a uniform application of the resulting multi-layer coating onto the surface of the cellulose carrier. The applicator, as claimed, consists of an equalizing stick (1) moving by translation on a sliding carriage (9) driven by a stepper motor (6) along a paper carrier (2) placed on a glass-plate table (3) with smooth surface, in which the operating parameters are controlled by an electronic control system.