Polymeric compositions, oil compositions containing said polymeric compositions, transmission fluids and hydraulic fluids

A transmission fluid composition having improved shear stability comprising

• (A) from about 0.1% to about 20% by weight of at least one oil-soluble homopolymer of a non-aromatic mono-olefin having at least three carbon atoms, said homopolymer having a number average molecular weight from about 850 to about 10,000,
• (B) at least one nitrogen-containing ester of a carboxy-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, said nitrogen-containing ester being characterized by the presence within its polymer structure 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 carbonylpolyamino group derived from reacting a carboxy group of said interpolymer with a polyamino compound having one primary or secondary amino group and at least one tertiary amino or heterocyclic amino group;
• and
• (C) from about 1% to about 90% by weight of at least one low temperature viscosity reducing organic diluent.

A hydraulic fluid having improved shear stability comprising a major amount of a base oil;

• (A) a minor shear stabilizing amount of at least one oil-soluble polymer which is a homopolymer of a non-aromatic mono-olefin having at least three carbon atoms, or a copolymer of said non-aromatic mono-olefin with an aromatic mono-olefin, said polymer having a number average molecular weigh tof about 500 to about 100,000;
• (B-1) a minor viscosity index improving amount of at least one nitrogen-containing ester of a carboxy-containing interpolymer obtained from (i) an aliphatic olefin or a vinyl aromatic monomer and (ii) at least one alpha, beta-unsaturated aliphatic carboxylic acid, anhydride or ester monomer thereof, said interpolymer having a reduced specific viscosity of from about 0.05 to about 2, said nitrogen-containing ester being characterized by the presence within its polymer structure 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 carbonylpolyamino 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;
• (B-2) a minor pour point depressing amount of at least one oil-soluble acrylate polyerization product of at least one ester of the formula:
• CH.sub.2 .dbd.C(X)--COOR
• wherein X is hydrogen or an alkyl or aryl group, and R is a monovalent hydrocarbyl group containing at least four carbon atoms or an ether derivative of said hydrocarbyl group;
• and
• (C) a minor fluidity improving amount of at least one low temperature viscosity reducing liquid organic diluent.