Conductive nonwoven fabric and method of producing meltblown nonwoven fabric used in conductive nonwoven fabric

Patent metadata

Field	Value
Publication number	US-10829879-B2
Application number	US-201415505495-A
Country	US
Kind code	B2
Filing date	Aug 22, 2014
Priority date	Aug 22, 2014
Publication date	Nov 10, 2020
Grant date	Nov 10, 2020

Abstract

Provided is a conductive nonwoven fabric, including a meltblown nonwoven fabric made from a melt liquid-crystal-forming wholly aromatic polyester having a melt viscosity at 310° C. of less than or equal to 20 Pa·s and satisfying (A) an average fiber diameter from 0.1 μm to 5 μm, (B) two or less film-like objects existing per 1 mm2 of the nonwoven fabric, (C) a breaking length in a warp direction of greater than or equal to 10 km and a breaking length in a weft direction of greater than or equal to 6 km, (D) a basis weight from 1.0 g/m2 to 15 g/m2, (E) a thickness from 5 μm to 50 μm, and (F) an air permeability of less than or equal to 300 cc/cm2/second, and a metal coating film formed on the meltblown nonwoven fabric.

First claim

The invention claimed is:

1. A conductive nonwoven fabric, comprising:
a meltblown nonwoven fabric comprising a melt liquid-crystal-forming wholly aromatic polyester having a melt viscosity at 310° C. of less than or equal to 20 Pas, the meltblown nonwoven fabric satisfying (A), (B), (C), (D), (E), and (F); and
a metal coating film formed on the meltblown nonwoven fabric:
(A) an average fiber diameter from 0.5 to 4 μm;
(B) two or less film-like objects existing per 1 mm 2 of the nonwoven fabric;
(C) a breaking length in a warp direction of greater than or equal to 10 km and a breaking length in a weft direction of greater than or equal to 6 km;
(D) a basis weight from 1.0 g/m 2 to 15 g/m 2 ;
(E) a thickness from 5 μm to 50 μm; and
(F) an air permeability of less than or equal to 82 cc/cm 2 /second.

2. The fabric of claim 1 , wherein the meltblown nonwoven fabric further satisfies satisfying (G):
(G) a surface roughness (Ra) of less than or equal to 15 μm.

3. The fabric of claim 1 , wherein the metal coating film comprises at least one selected from the group consisting of copper, nickel, gold, silver, cobalt, tin, and zinc.

4. The fabric of claim 1 , wherein the metal coating film comprises an alloy or a laminate film of at least two selected from the group consisting of copper, nickel, gold, silver, cobalt, tin, and zinc.

5. A conductive tape, comprising the fabric of claim 1 .

6. A method of producing a meltblown nonwoven fabric, the method comprising:
melt spinning a melt liquid-crystal-forming wholly aromatic polyester using a spinning nozzle to obtain a spun product while blowing the spun product at a spinning temperature from 310° C. to 360° C. with air in an amount from 5 Nm 3 to 30 Nm 3 per a width of the spinning nozzle of 1 m, thereby forming a web on a collecting plane; and
conducting heat treatment to produce the meltblown nonwoven fabric,
the melt spinning being conducted through the spinning nozzle having a nozzle spout size from 0.1 mm to 0.3 mm, a ratio (L/D) of a nozzle spout length (L) to the nozzle spout size (D) from 20 to 50, and a distance between nozzle spouts from 0.2 mm to 1.0 mm,
the heat treatment being conducted at a temperature of greater than or equal to <(a melting point of the melt liquid-crystal-forming wholly aromatic polyester) 40° C.> and less than or equal to <(the melting point of the melt liquid-crystal-forming wholly aromatic polyester)+20° C.> for a period of greater than or equal to 3 hours.

7. The method of claim 6 , further comprising: continuously treating the meltblown nonwoven fabric between an elastic roll having a surface Shore D hardness from 85° to 95° and a metal roll at a temperature from 100° C. to 250° C. and a linear pressure from 100 kg/cm to 500 kg/cm.

8. The method of claim 6 , wherein the ratio (L/D) is no more than 45.

9. The fabric of claim 1 , wherein the metal coating film comprises copper.

10. The fabric of claim 1 , wherein the metal coating film comprises nickel.

11. The fabric of claim 1 , wherein the metal coating film comprises gold.

12. The fabric of claim 1 , wherein the metal coating film comprises silver.

13. The fabric of claim 1 , wherein the metal coating film comprises cobalt.

14. The fabric of claim 1 , wherein the metal coating film comprises tin.

15. The fabric of claim 1 , wherein the metal coating film comprises zinc.

16. The fabric of claim 1 , wherein the average fiber diameter (A) is in a range of from 1 to 4 μm.

17. The fabric of claim 1 , wherein the average fiber diameter (A) is in a range of from 1 to 3 μm.

18. The fabric of claim 1 , wherein the air permeability (F) is at least 1 cc/cm 2 /second.

19. The fabric of claim 1 , wherein the polyester comprises, in polymerized form, p-hydroxybenzoic acid, 2-hydroxy-6-naphthoic acid, and/or biphenol.

20. The fabric of claim 1 , wherein the polyester comprises a repeating unit of the formula:

Assignees

• Kuraray Co

Inventors

• Shirotani Yasuhiro
• Houhashi Kimihiko
• Ohira Kazuo

Classifications

• D04H3/16 Primary

  with bonds between thermoplastic filaments produced in association with filament formation, e.g. immediately following extrusion · CPC title

• D06M11/83 Primary

  with metals; with metal-generating compounds, e.g. metal carbonyls; Reduction of metal compounds on textiles · CPC title

• D04H3/011

  Polyesters · CPC title

• D01F6/62

  from polyesters · CPC title

• D04H1/435

  Polyesters · CPC title