| 摘要 |
PURPOSE:To contrive to supply stably VDC-MA extruded product with high market request by using vinylidene chloride-methyl acrylate family copolymer (herein under mentioned as VDC-MA) prepared under a specified condition. CONSTITUTION:VDC-MA is prepared in such a manner that the relation of weight- average molecular weight having 3-15wt% MA component to 100wt% copolymer and the value of 70,000-250,000 measured by gel permeation chromatography method, to the contained ratio of copolymer contained in copolymer with molecular weight equal to 20,000 or less, becomes the value in the range of the quadrilateral defined by the straight line connecting four coordinate points, i.e. point A (70,000, 18), point B (150,000, 4), point C (250,000, 4) and point D (120,000, 18) in a normal coordinates with both logarithms graduated respectively such that average molecular weight is graduated on an abscissa (logarithmic scale) and the contained ratio of the copolymer with 20,000 or less molecular weight is graduated on an ordinate (logarithmic scale). Thus prepared material is used for VDC-MA. The contained amount of MA component is kept at 15% or less, and also a little modifying agent which does not remarkably deteriorate gas barrier property is added, whereby extruding moldability may be kept at excellent state. |
