HYDROPHOBIC TREATMENT OF WOOD

The present invention relates to a process for the esterification of all or some of the hydroxyl functions of a wood-type material and/or of one of the products derived therefrom, characterized in that said material is brought into contact with a fluid in a supercritical state carrying at least one natural unsaturated plant oil under conditions suitable for carrying out the esterification, and comprising at least the steps of: i) depositing, within a chamber, a wood-type material preferably having a water content of less than 20% by weight relative to its total weight and at least one natural unsaturated plant oil carried, preferably dissolved, in a liquid fluid capable of changing to a supercritical state under pressure; ii) subjecting the mixture to pressure conditions that are effective for the impregnation of the material by the oil; and iii) exposing the material impregnated by the oil obtained in step ii) to pressure and temperature conditions that are effective for causing the fluid to change to a supercritical state and carrying out the esterification reaction.