Conductive composite filament and process for producing the same

• US 5,318,845 A
• Filed: 01/13/1993
• Issued: 06/07/1994
• Est. Priority Date: 05/27/1988
• Status: Expired due to Term

• Current Assignee: Kuraray Company Limited
• Original Assignee: Kuraray Company Limited
• Inventors: Matsuo, Yoshiteru, Kawamoto, Masao, Tanaka, Kazuhiko, Asano, Shoji, Nakamura, Eiichirou
• Primary Examiner(s): Ryan, Patrick J.
• Assistant Examiner(s): EDWARDS, NEWTON
• Application Number:
  US08/004,186
• Time in Patent Office: 510 Days
• Field of Search: 57/210, 57/227, 57/228, 57/244, 57/248, 57/905, 57/245, 428/370, 428/364, 428/373, 428/399, 428/372
• US Class Current: 428/373
• CPC Class Codes: D01F 1/09 for making electroconductive or anti-static filaments
• CPC Class Codes: D01F 8/12 with at least one polyamide as constituent
• CPC Class Codes: Y10S 57/905 Bicomponent material
• CPC Class Codes: Y10T 428/2927 including structurally defined particulate matter
• CPC Class Codes: Y10T 428/2929 Bicomponent, conjugate, composite or collateral fibers or filaments [i.e., coextruded sheath-core or side-by-side type]
• CPC Class Codes: Y10T 428/2976 Longitudinally varying

Abstract

A highly oriented, undrawn, conductive, composite filament is provided, which is white or colorless and has antistatic properties durable over a long period when clothing utilizing the fiber are actually put on and washed. The filament is a sheath-core composite filament comprising a sheath of a fiber-forming thermoplastic polymer (A) and a core of a composition (B) comprising a conductive material which comprises a conductive metal oxide and a thermoplastic polyamide, having a core resistance of not more than 9×10¹⁰ Ω/cm·filament, the composite filament maintaining a critical elongation--an elongation reached in the course of extending a composite filament at which the core resistance exceeds 1×10¹¹ Ω/cm·filament at a D.C. voltage of 1 kV--of at least 5% and a shrinkage in hot water at 100° C. of not higher than 20%. Such fiber can be obtained by conducting high orientation melt spinning at a rate of at least 2,500 m/min while selecting a polyamide as the core component to contain the white or colorless conductive material and having the composition previously dried to a moisture content of 100 to 1,200 ppm.

Claims

1. A combined filament yarn comprising:

(1) a core of non-conductive polyethylene terephthalate multifilament yarn surrounded by

(2) a sheath of highly oriented, undrawn, conductive filament yarn, the filaments of said yarn each comprising;

(a) a conductive polyamide core containing therein at least one conductive metal oxide, said polyamide core having been adjusted to a moisture content of from about 100 to 1200 ppm during spinning of said conductive filament yarn, said polyamide core surrounded by

(b) a polyethylene terephthalate or polybutylene terephthalate sheath;

wherein,

said conductive filament yarn exhibits a resistance at a DC voltage of 1 kV of less than 9×

10¹⁰ Ω

/cm., filament, a critical elongation of at least 5%, a shrinkage in hot water at 100°

C. of 20% or less, and a yarn length of 0.5 to 15% greater than that of said non-conductive polyethylene terephthalate core, and wherein

the conductive filament yarn has a Young'"'"'s modulus and tensile strength smaller than that of said non-conductive polyethylene terephthalate core, said non-conductive polyethylene terephthalate core and said conductive filament yarn sheath being at least partially intermingled to form said combined filament yarn.

2. A combined filament yarn according to claim 1 wherein the non-conductive polyethylene terephthalate multifilament yarn of the core has a total fineness of 20 to 100 denier.

3. A combined filament yarn according to claim 1 wherein the weight ratio of the yarn comprising the non-conductive core to the yarn comprising the conductive sheath ranges from 1:

2 to 5;

1.