| 摘要 |
<p>PURPOSE:To manufacture an oriented material of good thickness accuracy and with little uneven shrinkage at the time of heat shrinking by specifying heat recovery rate in the both directions of two axes of a film of sheet-shaped copolymer pulling biaxial oriented material composed of specified weight ratio of methacrylic acid methyl and specified acrylic acid alkyl ester and having a specified value of melt flow index. CONSTITUTION:A film or sheet-shaped pulling biaxially oriented material of copolymer resin is composed of 99-85wt.% of methacrylic methyl unit and 1-15wt.% of acrylic acid alkyl ester unit having 1-4 carbon and having 0.5-12g/10min. of melt flow index and mechanical properties of 90% or more of heat recovery rate in the both directions of two axes improved isotropically. When the heat recovery rate of the oriented material is less than 90%, orientation degree is not uniform, which, for instance, generates large distortion of a picture drawn in the shrink art and also makes the dimension after shrinking not constant. On the other hand, when the rate is 90% or more, shrink art without noticeable distortion and of pre-arranged constant dimension is realized.</p> |
