| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of manufacturing a methacrylic resin which is little in the occurrence of silver streaks, foaming, discoloration, an odor and the like in thermoforming and excels in thermal decomposition resistance. SOLUTION: In the method of manufacturing the methacrylic resin, a mixture of 71-95 wt% methyl methacrylate alone or a monomer mixture of≥75 wt.% methyl methacrylate and≤25 wt.% at least one monomer selected from among methyl acrylate, ethyl acrylate, and butyl acrylate and 29-5 wt.% solvent are continuously polimerized, with the use of a complete mixing tank of a first stage reactor and and a plug flow type reactor of a second stage reactor which are connected in series in two stages, under the conditions that (1) the polymerization temperatures in the first stage complete mixing tank and the second stage plug flow type reactor are set; (2) the average residence times in the first stage complete mixing tank and that in the second stage plug flow type reactor are set by an initiator; (3) the concentration of the radical polymerization initiator based on the composition is controlled; (4) the concentration of a chain-transfer agent based on the composition is controlled; and (5) the monomer conversion at the outlet of the second stage plug flow type reactor is maintained at 70-90%. COPYRIGHT: (C)2004,JPO&NCIPI
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