Polyurethane elastic fiber nonwoven fabric and its production and synthetic leather using the same

• US 6,784,127 B1
• Filed: 09/24/2001
• Issued: 08/31/2004
• Est. Priority Date: 02/24/1999
• Status: Expired due to Term

• Current Assignee: KB Seiren, Ltd.
• Original Assignee: Kanebo, Ltd. (HOYU Company Limited), Kanebo Gohsen, Ltd.
• Inventors: Tanaka, Yutaka, Yamakawa, Yukio, Kawabata, Eiji, Furuya, Tadashi
• Primary Examiner(s): Juska, Cheryl A.
• Assistant Examiner(s): JOHNSON, JENNA LEIGH
• Application Number:
  US09/890,742
• Time in Patent Office: 1,072 Days
• Field of Search: 442/104, 442/105, 442/400, 442/401, 442/409, 442/414, 428/365, 428/904
• US Class Current: 442/409
• CPC Class Codes: B32B 27/12 next to a fibrous or filamentary layer
• CPC Class Codes: D04H 1/42 characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
• CPC Class Codes: D04H 1/4358 Polyurethanes
• CPC Class Codes: D04H 1/72 the fibres being randomly arranged
• CPC Class Codes: D04H 3/02 characterised by the method of forming fleeces or layers, e.g. reorientation of yarns or filaments
• CPC Class Codes: D04H 3/14 with bonds between thermoplastic yarns or filaments produced by welding
• CPC Class Codes: D06N 3/0027 Rubber or elastomeric fibres
• CPC Class Codes: Y10S 428/904 Artificial leather
• CPC Class Codes: Y10T 428/2915 including textile, cloth or fabric
• CPC Class Codes: Y10T 442/2369 Coating or impregnation improves elasticity, bendability, resiliency, flexibility, or shape retention of the fabric
• CPC Class Codes: Y10T 442/2377 Improves elasticity
• CPC Class Codes: Y10T 442/69 Autogenously bonded nonwoven fabric
• CPC Class Codes: Y10T 442/696 Including strand or fiber material which is stated to have specific attributes [e.g., heat or fire resistance, chemical or solvent resistance, high absorption for aqueous compositions, water solubility, heat shrinkability, etc.]

Abstract

A polyurethane elastomer fiber non-woven fabric contains polyurethane elastomer fiber filaments melt-bonded with one another, and has a tensile elongation of 100% or more, a 50% elongation recovery of 75% or more and a tear strength per METSUKE of 5.5 gf or more. The non-woven fabric can be prepared by a method of providing a thermoplastic polyurethane elastomer having Shore hardness A of 92 or more, drying the elastomer to a water content of 150 ppm or less, and melt-spinning and, at the same time, spraying it together with a high speed gas stream so as to deposit and laminate the elastomer into a sheet form. A synthetic leather using the non-woven fabric is also provided. The non-woven fabric has not only an excellent elasticity but also high tear strength.

Claims

1. A non-woven polyurethane fabric comprising polyurethane elastic fiber filaments which are mutually fused and bonded and having a tensile elongation of not less than 100%, a recovery at 50% elongation of not less than 75% and a tear strength per basis weight of not less than 5.5 gf, said fabric being produced by dehydrating a thermoplastic polyurethane elastomer having a Shore A hardness of not less than 92 to reduce the moisture content thereof to no more than 150 ppm, melt-spinning the thermoplastic polyurethane elastomer and depositing and laminating the filaments in a sheet form at a temperature which is 35°

C. lower than the Vicat softening temperature.

2. A synthetic leather comprising a base material layer made of a non-woven polyurethane fabric comprising polyurethane elastic fiber filaments which are mutually fused and bonded and having a tensile elongation of not less than 100%, a recovery at 50% elongation of not less than 75% and a tear strength per basis weight of not less than 5.5 gf, said fabric being produced by dehydrating a thermoplastic polyurethane elastomer having a Shore A hardness of not less than 92 to reduce the moisture content thereof to no more than 150 ppm, melt-spinning the thermoplastic polyurethane elastomer and depositing and laminating the filaments in a sheet form at a temperature which is 35°

C. lower than the Vicat softening temperature.