| 摘要 |
PURPOSE:To obtain an extruded sheet, which is made of methyl methacrylate polymer having specified molecular weight and the internal strain in the extrusion direction of which is the specified amount or less and which does not shrink at hot processing, by a method wherein peripheral speed difference is realized between forming rolls. CONSTITUTION:The methyl methacrylate polymer concerned means copolymer or homopolymer containing 75% or more of methyl methacrylate having a molecular weight of 220,000 or less. The forming roll, which comes into close content firstly and that, which comes into close contact lastly, mean forming rolls 4 and 5 in case of a three-roll calendar, round which resin is wound closely. The provision of negative peripheral speed difference between forming rolls means to make the peripheral speed of the forming roll, which comes into close contact lastly, slower than that of the forming roll, which comes into close contact firstly. By providing the negative peripheral speed difference between the forming rolls, an acrylic resin extruded sheet, the internal strain in the extrusion direction of which is small or concretely 2% or less, can be obtained. |
