| 摘要 |
The present invention provides emulsion copolymers and coating compositions containing the same having improved room temperature and hot block resistance in 5 coatings wherein the copolymers have a broad measured glass transition temperature and are the copolymerization product of a vinyl monomer composition A and a softer vinyl monomer composition B having a Hansch parameter of at least 3.2, and containing one or more vinyl monomer M, such that each of which vinyl monomer(s) M would when homopolymerized provide a homopolymer having a .0 measured Tg of 200C or less, such as, for example, 2-ethylhexyl acrylate. In addition, the present invention provides methods for making the emulsion copolymers by a powerfeed process comprising feeding vinyl monomer composition A into a reactor from a feed vessel while feeding, simultaneously or after a delay, vinyl monomer composition B into the feed vessel while polymerizing the monomers in the reactor. |
