Patent ID: 7056984

Claim:
A method of producing an acrylic syrup in which a grafted rubber which is at least part of a polymerized solid component has a branching coefficient with which the slope obtained by double-logarithmically plotting the RMS radius (z-average inertial radius) calculated from the GPC-MALLS measurement and the molecular weights, is 0.35 to 0.65 (nm/(g/mol)), comprising the steps of: (i) preparing a starting solution by dissolving a rubbery polymer in a vinyl monomer containing at least 85% by weight of methyl methacrylate, said rubbery polymer being dissolved in an amount of 2 to 20 parts by weight per 100 parts by weight of a total amount of said vinyl monomer and a vinyl monomer for post-addition; (ii) heating said starting solution in a nonoxidizing atmosphere and, then, adding a chain transfer agent to said starting solution under a reflux condition; (iii) adding a polymerization initiator and a vinyl monomer which is for the post-addition containing at least 85% by weight of methyl methacrylate over a period of from 0.5 to 8 hours continuously or in a divided manner under a reflux condition after the chain transfer agent has been added; and (iv) continuing the heating to conduct the reflux for from 0.01 to 10 hours after the polymerization initiator and the vinyl monomer for post-addition have been added.