Polymeric compositions comprising olefin polymer and nitrogen containing ester of a carboxy interpolymer

A polymeric composition comprising a mixture of

• (A) at least one oil-soluble homopolymer of a nonaromatic mono-olefin having at least three carbon atoms, said homopolymer having a number average molecular weight of about 750 to about 50,000 and
• (B-1) at least one nitrogen-containing interpolymer derived from at least two monomers, one of said monomers being
• (i) an aliphatic olefin or a vinyl aromatic monomer, and the other of said monomers being
• (ii) at least one alpha, beta-unsaturated aliphatic carboxylic acid, anhydride or ester thereof, said interpolymer having a reduced specific viscosity of from about 0.05 to about 2 and said nitrogen-containing ester being characterized by the presence within its polymer structure of at least one of each of the following polar groups which are derived from the carboxy groups of said interpolymer:
• (a) at least one carboxylic ester group having at least 8 aliphatic carbon atoms in the ester group,
• (b) at least one carbonyl-polyamino group derived from reacting a carboxy group of said interpolymers with a polyamino compound having one primary or secondary amino group and at least one tertiary amino or heterocyclic amino group and
• (c) at least one carboxylic ester group having no more than 7 aliphatic carbon atoms in the ester group.