Ultra-high-tenacity polyvinyl alcohol fiber and process for producing same

• US 4,603,083 A
• Filed: 12/12/1984
• Issued: 07/29/1986
• Est. Priority Date: 12/12/1983
• Status: Expired due to Term

• Current Assignee: Toray Industries Incorporated
• Original Assignee: Toray Industries Incorporated
• Inventors: Suzuki, Mitsuo, Tanaka, Hiroyoshi, Ueda, Fujio
• Primary Examiner(s): Kendell, Lorraine T.
• Application Number:
  US06/680,721
• Time in Patent Office: 594 Days
• Field of Search: 428/364, 264/185, 264/210.8, 525/56, 525/319
• US Class Current: 428/364
• CPC Class Codes: D01F 6/14 from polymers of unsaturated alcohols, e.g. polyvinyl alcohol, or of their acetals or ketals
• CPC Class Codes: Y10T 428/2913 Rod, strand, filament or fiber
• CPC Class Codes: Y10T 428/2929 Bicomponent, conjugate, composite or collateral fibers or filaments [i.e., coextruded sheath-core or side-by-side type]

Abstract

An ultra-high-tenacity multifilament fiber of polyvinyl alcohol having a degree of polymerization of at least 1500, said filament having a tensile strength of at least 12 g/d and an initial modulus greater than 280 g/d, which is produced by a process for producing an ultra-high-tenacity polyvinyl alcohol fiber which comprises the steps of dissolving polyvinyl alcohol having a degree of polymerization of at least 1500 in a solvent, dry-spinning the resulting polymer solution through a spinneret into an environment of air or inert gas, introducing the dry-spun filaments into a coagulating bath, and drawing the coagulated filaments at a total effective draw ratio of at least 20 times.

Claims

1. An ultra-high tenacity filament of polyvinyl alcohol having a degree of polymerization of at least 1500, a fineness lower than 10 deniers, a residual elongation lower than 5%, a tensile strength of at least 12 g/d and an initial modulus of at least 280 g/d.

2. An ultra-high-tenacity polyvinyl alcohol filament as claimed in claim 1, which is produced by the dry-jet wet spinning process.

3. An ultra-high-tenacity polyvinyl alcohol filament as claimed in claim 1, which has a tensile strength of at least 15 and an initial modulus of at least 300 g/d.

4. An ultra-high-tenacity polyvinyl alcohol filament as claimed in claim 1, which is produced from polyvinyl alcohol having a degree of polymerization of at least 2500 and has a tensile strength of at least 17.5 g/d and an initial modulus of at least 350 g/d.

5. An ultra-high-tenacity polyvinyl alcohol filament as claimed in claim 1, which has birefringence of at least 50×

10^-3 and has no long-period patterns arising from small-angle X-ray scattering.

6. An ultra-high-tenacity polyvinyl alcohol filament as claimed in claim 1, having a fineness lower than 5 deniers.

7. An ultra-high-tenacity polyvinyl alcohol filament as claimed in claim 1, having a fineness lower than 3 deniers and a round or oval cross-section.