| 摘要 |
<p>Aqueous polymer dispersion comprises at least one core copolymer (A) and at least one shell copolymer (B), where the glass transition temperature (T g) of the core is 70-100[deg] C, the T gof the shell is 20-55[deg] C, the total T gof the core-shell copolymer is 30-80[deg] C and the dispersion contains an emulsifier content of = 1.5 wt.%, relative to the solid substance. An independent claim is included for preparing the above polymer dispersion, comprising (a1) providing water, emulsifier and optionally a small quantity of initiator, (a2) subsequently adding a content of the monomers ((i) 1-20C alkyl(meth)acrylate, (ii) vinyl aromatic compounds having up to 20C and (iii) acid functional monomer) of 1-10 wt.% optionally simultaneously during the addition of the initiator for forming an internal seed, (a3) adding the monomers ((i)-(iii) and (iv) optional hydroxy functional monomer), for the copolymer (A) (core) in step-wise manner, (a4) polymerizing up to a quantity of at least 5 wt.%, relative to its total weight, (a5) adding the monomers (i)-(iv) for the copolymer (B), and (a6) polymerizing up to a quantity of at least 5 wt.%, relative to its total weight.</p> |
