Dyed sheath/core fibers and methods of making same

• US 6,531,218 B2
• Filed: 04/30/2001
• Issued: 03/11/2003
• Est. Priority Date: 09/16/1996
• Status: Expired due to Term

• Current Assignee: SHAW Industries Group Incorporated (Berkshire Hathaway Incorporated)
• Original Assignee: BASF Corporation (BASF SE)
• Inventors: Shore, Gary W., McIntosh, Stanley A., Hoyt, Matthew B., Bailey, Bobby J., Wilson, Phillip E.
• Primary Examiner(s): EDWARDS, NEWTON O
• Application Number:
  US09/844,269
• Publication Number:
  US 20020004137A1
• Time in Patent Office: 680 Days
• Field of Search: 428/370, 428/373, 428/374
• US Class Current: 428/370
• CPC Class Codes: D01D 5/253 with a non-circular cross section; Spinnerette packs therefor D01D5/38 takes precedence
• CPC Class Codes: D01F 8/12 with at least one polyamide as constituent
• CPC Class Codes: Y10T 428/2924 Composite
• 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 428/2931 Fibers or filaments nonconcentric [e.g., side-by-side or eccentric, etc.]

Abstract

Dyeable and dyed filaments have a core and a sheath which entirely surrounds the core. The core is formed of a core polymer which is susceptible to dyeing by a dye bath chemical, while the sheath is formed of a sheath polymer which is resistant to dyeing by the dye bath chemical. When the filament is brought into contact with a dye bath containing the dye chemical, the dye chemical in the dye bath will physically diffuse or migrate through the sheath polymer to cause the core polymer to be dyed a color of the dye bath chemical, while the sheath polymer is substantially undyed thereby.

Claims

1. A sheath/core filament comprising a sheath formed of an essentially non-dyeable nylon sheath polymer which is resistant to, and thereby essentially undyed by, dyes, and a core entirely surrounded by the sheath and formed of a dyeable core polymer which is susceptible to dyeing by the dyes, wherein said filament includes less than about 10 wt. % of said sheath polymer.

2. The filament of claim 1, which is a trilobal filament.

3. The filament of claim 1, which has between about 90 wt. % to about 97 wt. % of the core polymer, and between about 3 wt. % to about 10 wt. % of the sheath polymer.

4. The filament of claim 3, wherein the core polymer is a nylon having an amine end group content (AEG) of between about 10 meq/kg to about 100 meq/kg, and wherein the sheath polymer is a nylon having an AEG of less than about 10 meq/kg.

5. The filament of claim 4, wherein the nylon sheath polymer has an AEG content of less than about 5 meq/kg.

6. The filament of claim 5, wherein the nylon sheath polymer is a nylon-6,12 homopolymer.

7. The filament of claim 1, wherein the core is a nylon polymer which is at least one selected from the group consisting of nylon-6, nylon-12, nylon-11, nylon-6/6, nylon-6/10 and copolymers and blends thereof.

8. The filament of claim 7, wherein the core nylon polymer has an amino end group (AEG) content of between about 10 meq/kg and about 100 meq/kg.