High Young's modulus poly-p-phenylene terephthalamide fiber
AssigneeAsahi Kasei Kogyo Kabushiki Kaisha
InventorsTakashi Fujiwara, Shuji Kajita, Tetsuo Matsushita, Seiichi Manabe
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Abstract
A high Young's modulus poly-p-phenylene-terephthalamide fiber having a unique fine-structure and excellent properties, including excellent resistance to lateral stress and to friction. The fiber is made by extruding an anisotropic dope in a non-coagulating layer, passing the extrudate through a coagulating layer, washing and drying the resulting coagulated fibers in the absence of substantial tension, and heating the fibers under tension.
Claims9
A high Young's modulus fiber consisting essentially of poly-p-phenylene-terephthalamide wherein the tangential refractive index (TRIv) of the fiber by polarized light vibrating in the direction perpendicular to the fiber axis is in the range of from 0.06 to 0.10, the tangential refractive index (TRIp) of the fiber by polarized light vibrating in the direction parallel to the fiber axis is in the range of from -0.020 to +0.020, the central refractive index (Nvo) of the fiber by polarized light vibrating in the direction perpendicular to the fiber axis and the X-ray diffraction intensity ratio (RIX) are in the range satisfying the conditions of the formulae (1) through (4):
- Nvo.gtoreq.-0.08(RIX)+1.670 (1)
- Nvo.ltoreq.1.640 (2)
- RIX.gtoreq.0.85 (3)
- RIX.ltoreq.1.10 (4),
- and the apparent crystallite size (ACS in A) of the fiber and the orientation angle (OA in degrees) of the fiber are in the range circumscribed by the four lines (a), (b), (c), and (d) defined by the formulae (5) through (8) as illustrated in FIG. 1:
- OA.gtoreq.0.10 (ACS)+4.8 (5)
- OA.gtoreq.0.40 (ACS)-19.8 (6)
- OA.ltoreq.0.05 (ACS)+13.3 (7)
- OA.ltoreq.3 (ACS)-146 (8).
Dependencies are inferred from the claim text.