| 摘要 |
PROBLEM TO BE SOLVED: To provide a transparent plastic sheet for a frame or the like hard to generate the undulation phenomenon or expansion and contraction phenomenon caused by a change in temperature or humidity, having rigidity enhancing plane keeping properties and having a high thermal deformation temperature. SOLUTION: The transparent plastic sheet comprises at least three layers and the hardness of the outer layers 1 and 2 is made different from that of the inner layer 3. Alternatively, the transparent plastic sheet comprises at least three layers and the thickness of both outer layers 1 and 2 is same to or less than that of the inner layer 3 and the both outer layers are higher than the inner layer in hardness, rigidity, heat resistance and flexibility.
|
