Polymethylmethacrylate resin with an impact modifier capsulated therein and a process of preparing for the same

A process for producing a PMMA resin with an impact modifier capsulated therein which comprises the following three emulsion polymerizing stages:

• Conducting a first emulsion polymerizing stage for preparing a granular emulsion of a glass polymer for a core with a conversion ratio of 93-99% and an average diameter of 80-200 nm, by adding the composition of a part of the first monomers, deionized water, an emulsifier, a grafting agent, and a crosslinking agent under a nitrogen atmosphere, into a reactor, heating and agitating the composition, emulsion-polymerizing the composition adding a polymerization initiator thereto when the temperature of the composition reaches 50-90° C., continuously polymerizing the composition while adding the remaining first monomer to form a seed emulsion, and finally inputting the initiator into the composition at the end of the polymerizing step,
• Conducting a secondary emulsion polymerizing stage for producing the polymer emulsion grafted to the glass polymer granule core a the conversion ratio of 93˜99% and an average thickness of 10-150 nm, by agitating the emulsion at a temperature of 50-90° C., adding an emulsifier, a crosslinking agent, and the secondary monomers of at least one of butylacrylate or butadiene and styrene, and inputting the polymerization initiator at the end of the polymerizing;
• Conducting a third emulsion polymerizing stage for producing a PMMA resin with an impact modifier capsulated therein with a conversion ratio is of more than 95%, in which a glass polymer (outer layer) is grafted to the rubber polymer (intermediate layer) with the thickness of 60˜3000 nm, by continuously polymerizing and adding the third monomers and polymerization initiator, and adding a chain transfer agent and polymerization initiator at the end of the polymerization.