Thermoplastic composition

A composition comprising a particulate solid, a plastic material and a compound, wherein the compound represented by Formula (1):

• T-G-Z
• wherein:
• T is a lipophilic component of an alk(en)yl group containing 6 or more carbon atoms, a polyester, or mixtures thereof;
• G is an acylating group;
• Z is —N(R)j or —N(R)v(B-D)-, bonded to a carbonyl group of G to form either an amide or imide group;
• j is 1 or 2, R is independently H or a C1-18 alk(en)yl group with the proviso when j is 2 each R group can be the same or different;
• v is 0 or 1, with the proviso that when v is 1, R is independently H or a C1-18 alk(en)yl group, and when v is 0 nitrogen forms an imide group;
• B is an alkylene radical, a hydroxyalkylene radical, a nitrogen-containing alkylene radical, a nitrogen-containing hydroxyalkylene radical, or mixtures thereof;
• and
• D is a primary or secondary amino group on which is attached one or more T-CO— groups.