PROCESS FOR SUPERCRITICAL OR SUBCRITICAL PARTIAL DELIGNIFICATION AND FILLING OF A LIGNOCELLULOSIC MATERIAL

The invention concerns a process for treating lignocellulosic material， preferably wood， comprising the following successive steps: * (1) extracting lignin by a fluid in supercritical or subcritical phase to extract 40 to 85% by weight % of the lignin of the initial material; * (2) filling by a filling compound， preferably in the presence of a fluid in supercritical or subcritical phase; and * (3) finishing， so as to obtain a composite material formed by a three-dimensional network of filling compound that is transformed and incorporated in a network of cellulose and lignin.