| 摘要 |
1,064,494. Wet-spinning. ACSA, APPLICAZIONI CHIMICHE S.p.A. Sept. 19, 1963 [Sept. 27, 1962], No. 36893/63. Heading B5B. A solution of a vinyl chloride polymer having a syndiotacticity greater than 2, maintained at 90‹ C. to 150‹ C. is wet spun by extrusion into a coagulation bath maintained at 30‹ C. to 80‹ C., the spinning solution and the coagulum bath being in containers adjacent to one another but thermally isolated from one another to an extent sufficient to maintain the stated temperature difference between them. Apparatus for the process comprises means for maintaining the spinning solution at the desired temperature and a vessel for holding the coagulum bath provided with an opening in its side in which a spinneret is fixed so that, when the vessel is filled, only the spinneret face is in contact with the bath. In one embodiment (not shown), spinning solution passes from a tank via duct (1) to metering pump (2), filter (3) and thence to spinneret (4) which is attached to spinneret holder (5) directly coupled to vessel (6) containing coagulating liquid. The temperature of the spinning solution is maintained by jacket (7) in which hot oil circulates. The difference in temperature between spinning solution and coagulating liquid may be e.g. 40‹ C. to 100‹ C. thus permitting the spinning of polymers which require a high spinning solution temperature but a volatile coagulating bath. Specified solutions are solutions of highly syndiotactic vinyl chloride homopolymer or copolymers or polymer mixtures containing not less than 85% by weight of vinyl chloride in cyclohexanone, dimethylformamide, dimethylacetamide or nitrobenzene. Specified coagulants are water, methanol, ethanol, isopropanol, acetone, acetic acid and tert-butanol.
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