Abrasive Cloth and Method for Producing Nanofiber Structure

• US 20070218279A1
• Filed: 04/20/2005
• Published: 09/20/2007
• Est. Priority Date: 04/21/2004
• Status: Active Grant

• Current Assignee: Toray Industries Incorporated
• Original Assignee: Toray Industries Incorporated
• Inventors: Ochi, Takashi, Nonaka, Shuichi, Matsunase, Takeo, Naruse, Yoshihiro
• Granted Patent: US 8,895,458 B2
• Time in Patent Office: Days
• US Class Current: 428/365
• CPC Class Codes: B24B 37/24 characterised by the composition or properties of the pad materials
• 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 1/4383 sea-island
• CPC Class Codes: D04H 1/43835 Mixed fibres, e.g. at least two chemically different fibres or fibre blends
• CPC Class Codes: D04H 1/43838 Ultrafine fibres, e.g. microfibres
• CPC Class Codes: Y10T 428/2915 including textile, cloth or fabric
• CPC Class Codes: Y10T 442/2008 Fabric composed of a fiber or strand which is of specific structural definition
• CPC Class Codes: Y10T 442/2861 Coated or impregnated synthetic organic fiber fabric
• CPC Class Codes: Y10T 442/2893 Coated or impregnated polyamide fiber fabric
• CPC Class Codes: Y10T 442/608 Including strand or fiber material which is of specific structural definition
• CPC Class Codes: Y10T 442/614 Strand or fiber material specified as having microdimensions [i.e., microfiber]
• CPC Class Codes: Y10T 442/626 Microfiber is synthetic polymer
• CPC Class Codes: Y10T 442/659 Including an additional nonwoven fabric

Abstract

An abrasive cloth which comprises an article in a sheet form having, in at least a part thereof, nanofibers comprising a thermoplastic polymer and having a number average single fiber fineness of 1×10⁻⁸ to 2×10⁻⁴ dtex wherein the sum of single fiber fineness percentages (which is defined in the specification) of a single fiber fineness of 1×10⁻⁸ to 2×10⁻⁴ dtex is the range of 60% or more, and exhibits a stress at 10% elongation in a longitudinal direction of 5 to 200 N/cm-width; and a method for preparing a nanofiber structure, which comprises providing a nanofiber dispersion having a dispersant and, dispersed therein, nanofibers comprising a thermoplastic polymer and having a number average diameter of 1 to 500 nm, attaching the dispersion to a support, and then removing said dispersant. The above abrasive cloth is excellent in texturing characteristics, and the above method allows the preparation of a nanofiber structure wherein nanofibers form a composite with the support.

Claims

1. An abrasive cloth comprising a sheet-like material having at least in its part nanofibers made of a thermoplastic polymer, the nanofibers having a number average single fiber fineness of 1×

10<sup>−

8</sup> to 4×

10<sup>−

4</sup> dtex and the sum of fineness ratios of single fiber finenesses in the range of 1×

10<sup>−

8</sup> to 4×

10<sup>−

4</sup> dtex of 60% or more,

wherein stress at 10% elongation in a longitudinal direction is in the range of 5 to 200 N/cm width.

3. The abrasive cloth according to claim 1 or 2, wherein 50% or more of the nanofibers in a single fiber fineness ratio falls within a width of 30 nm in a single fiber diameter difference.

4. The abrasive cloth according to claim 1 or 2, wherein the sheet-like material is made of a nonwoven fabric.

5. The abrasive cloth according to claim 1 or 2, wherein the sheet-like material is made of a woven fabric.

6. The abrasive cloth according to claim 1 or 2, wherein the sheet-like material is made of a knitted fabric.

7. The abrasive cloth according to claim 1 or 2, wherein a ratio S between a value of compressive elasticity of the sheet-like material under a load of 0.1 kg/cm² and that under a load of 0.5 kg/cm² is 4.0 or less.

8. The abrasive cloth according to claim 1 or 2, wherein an abrasion resistance coefficient of the sheet-like material is 50 mg or less.

9. The abrasive cloth according to claim 1 or 2, wherein a surface roughness value of the sheet-like material is 100 μ

m or less.

10. The abrasive cloth according to claim 1 or 2, wherein a surface hardness value of the sheet-like material is 20 or more.

11. The abrasive cloth according to claim 1 or 2, wherein the sheet-like material has at least on its one surface a napped surface composed of the nanofibers.

12. The abrasive cloth according to claim 1 or 2, wherein the sheet-like material is formed in such a way that nanofibers are laminated on a support.

13. The abrasive cloth according to claim 12, wherein a thickness of the nanofiber laminated layer is 70% or less of a thickness of the whole sheet-like material.

14. The abrasive cloth according to claim 1 or 2, wherein the sheet-like material has a space inside thereof, and the space is impregnated with a polymeric elastomer.

15. The abrasive cloth according to claim 14, wherein the polymeric elastomer is polyurethane.

16. The abrasive cloth according to claim 14, wherein a content of the polymeric elastomer is in the range of 20 to 60 wt. % of a fiber weight of the sheet-like material.

2. An abrasive cloth comprising a sheet-like material having at least in its part nanofibers made of a thermoplastic polymer, the nanofibers having a number average single fiber fineness of 1×

10<sup>−

8</sup> to 2×

10<sup>−

4</sup> dtex and the sum of fineness ratios of single fiber finenesses in the range of 1×

10<sup>−

8</sup> to 2×

10<sup>−

4</sup> dtex of 60% or more,

wherein stress at 10% elongation in a longitudinal direction is in the range of 5 to 200 N/cm width.

17. A method for producing a nanofiber structure, wherein a nanofiber dispersion liquid in which nanofibers having a number average diameter of 1 to 500 nm and made of a thermoplastic polymer are dispersed in a dispersion medium is attached to a support, and then the dispersion liquid is removed.

18. The method for producing a nanofiber structure according to claim 17, wherein the nanofibers made of the thermoplastic polymer have a number average diameter of 1 to 200 nm.

19. The method for producing a nanofiber structure according to claim 17, wherein in order to attach the nanofiber dispersion liquid to the support, the nanofiber dispersion liquid is sprayed and thereby attached to the support.

20. The method for producing a nanofiber structure according to claim 17, wherein in order to attach the nanofiber dispersion liquid to the support, the support is immersed into the nanofiber dispersion liquid to be thereby attached with the nanofiber dispersion liquid.

21. The method for producing a nanofiber structure according to claim 17, wherein in order to attach the nanofiber dispersion liquid to the support, the nanofiber dispersion liquid is coated on the support.

22. The method for producing a nanofiber structure according to claim 17, wherein a porous support is used as the support.

24. The method for producing a nanofiber structure according to claim 17 or 23, wherein a concentration of the nanofibers contained in the nanofiber dispersion liquid is in the range of 0.0001 to 1 wt. %.

25. The method for producing a nanofiber structure according to claim 17 or 23, wherein a concentration of the nanofibers contained in the nanofiber dispersion liquid is in the range of 0.001 to 0.1 wt. %.

26. The method for producing a nanofiber structure according to claim 17 or 23, wherein a concentration of a dispersant contained in the nanofiber dispersion liquid is in the range of 0.00001 to 20 wt. %.

27. The method for producing a nanofiber structure according to claim 17 or 23, wherein a concentration of a dispersant contained in the nanofiber dispersion liquid is in the range of 0.0001 to 5 wt. %.

28. The method for producing a nanofiber structure according to claim 26, wherein the dispersant is at least one type selected from the group consisting of a nonionic dispersant, an anionic dispersant, and a cationic dispersant.

29. The method for producing a nanofiber structure according to claim 28, wherein a zeta potential of the nanofiber falls within the range of −

5 to +5 mV, and the dispersant is the nonionic dispersant.

30. The method for producing a nanofiber structure according to claim 28, wherein a zeta potential of the nanofiber is not less than −

100 mV and less than −

5 mV, and the dispersant is the anionic dispersant.

31. The method for producing a nanofiber structure according to claim 28, wherein a zeta potential of the nanofiber exceeds +5 mV and is not more than 100 mV, and the dispersant is the cationic dispersant.

32. The method for producing a nanofiber structure according to claim 26, wherein a molecular weight of the dispersant is in the range of 1000 to 50000.

33. The method for producing a nanofiber structure according to claim 17 or 23, wherein a fiber ratio of single fibers contained in the nanofibers and falling within a diameter range more than 500 nm and not more than 1 μ

m is 3% or less.

34. The method for producing a nanofiber structure according to claim 17 or 23, wherein the support is composed of at least one structure selected from the group consisting of a nonwoven fabric, paper, a woven fabric, a knitted fabric, and foam.

23. A method for producing a nanofiber structure, wherein nanofibers having a number average diameter of 1 to 500 nm and made of a thermoplastic polymer are dispersed in a dispersion medium to thereby prepare a nanofiber dispersion liquid, and then the nanofiber dispersion liquid is subjected to papermaking with a use of a porous support as a base.