C.Further examples of acetovinylic resins useable in the binding compositions of this invention are the acetovinylic homopolymers plasticized with external additives in a quantity between 5 and 50% by weight on the dry homopolymer.Examples of the above-mentioned additives are the organic phthalates such as the di-n-or i-butylphthalates, the butylbenzylphthalates, etc., the organic phosphates such