PROCESS FOR ACYLATION OF A HYDROXYLATED SOLID MATERIAL

A process for acylation of a solid material (3, 9) bearing reactogenic hydroxyls includes at least one fatty acid chloride (1) is distributed at least on the surface of the solid material (3, 9) using a distributor device (2) having an application surface. At least one fatty acid chloride (1) is distributed at least on the surface of the solid material (3, 9) is heated at a temperature, referred to as acylation temperature, below the vaporization temperature of the at least one fatty acid chloride (1), so as to enable an acylation of the solid material (3, 9). A stream of a gaseous composition (6) is directed over the said solid material (3, 9) at the acylation temperature, so as to entrain at least one portion of gaseous hydrochloric acid (7) formed by the acylation reactionThe application surface of the distributor device (2) is a velvet provided with velvet filiform elements that are suitable for taking up the at least one fatty acid chloride (1) by contact with the at least one fatty acid chloride, and releasing at least one fatty acid chloride by bringing the filiform elements of the velvet into contact with the solid material (3, 9). The distribution step (12, 14) is carried out so as to distribute over the solid material (3, 9) an amount of the at least one fatty acid chloride (1) of between 20 mg/m2 and 1 g/m2 surface area of the solid material (3, 9).