A copolymer comprising units derived from (a) methacrylic acid esters containing from about 9 to about 25 carbon atoms in the ester group and (b) methacrylic acid esters containing from 7 to about 12 carbon atoms in the ester group, said ester groups having 2-(C1-4 alkyl)- substituents, and optionally (c) at least one monomer selected from the group consisting of methacrylic acid esters containing from 2 to about 8 carbon atoms in the ester group atoms and which are different from methacrylic acid esters (a) and (b), vinyl aromatic compounds, and nitrogen-containing vinyl monomers with the proviso that no more than 60% by weight of the esters contain not more than 11 carbon atoms in the ester group. Also described are additive concentrates and lubricating oil compositions containing the copolymers and processes for preparing copolymers.
一种共聚物,其组成单元来自(a)酯基中含有约 9 至约 25 个碳原子的
甲基丙烯酸酯和(b)酯基中含有 7 至约 12 个碳原子的
甲基丙烯酸酯,所述酯基具有 2-(C1-4烷基)-取代基、(c) 至少一种单体,选自酯基原子中含有 2 至 8 个碳原子且不同于
甲基丙烯酸酯 (a) 和 (b)、
乙烯基芳香族化合物和含氮
乙烯基单体的
甲基丙烯酸酯,但以重量计,不超过 60% 的酯在酯基中含有不超过 11 个碳原子。此外,还介绍了含有共聚物的添加剂浓缩物和润滑油组合物,以及制备共聚物的工艺。