| abstract |
A sheet-like material comprises a composition mainly consisting of high molecular weight poly p-phenylene- sulfide, characterised in that: a) the amount of extract thereof through chloroform extraction is less than 1.5 weight % of the total weight prior to said extraction, and b) i. the index of crystallinity thereof is in the range above 2.5 and below 8.0, ii. the size of crystallite thereof is in the range above 50 ANGSTROM and below 100 ANGSTROM , and iii. orientation factors thereof measured in three directions of through, Edge and End are respectively above 0.70, as measured by wide angle X-ray diffraction method. The sheet-like material may be laminated to a thin metallic film to produce a printed circuit board. |