| 摘要 |
PROBLEM TO BE SOLVED: To provide a (meth)acrylic polymer with improved impact resistance. SOLUTION: A multi-stage core-shell particle comprises a core, a first shell, and optionally a second shell, and is substantially free from vinylically unsaturated compounds having at least two equally reactive double bonds, wherein (i) the core contains a first (meth)acrylic polymer; (ii) the first shell contains a low Tg polymer comprising 0-25 wt.% of a styrenic monomer and 75-100 wt.% of a (meth)acrylic monomer and capable of forming a homopolymer having a Tg in the range of -75 to -5°C, and the first shell constitutes >65 vol.% of the combined volume of the core and first shell; (iii) the second shell, when present, contains a second (meth)acrylic polymer which may be identical to or different from the first (meth)acrylic polymer; and (iv) the core and the first shell both contain 0.5-1.0 wt.% of a graft-crosslinker. COPYRIGHT: (C)2010,JPO&INPIT |
