Abrasive cloth and method for producing nanofiber structure
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.
1. An abrasive cloth comprising a sheet material comprising polyurethane and having nanofibers of various finenesses made by a melt spinning method of a thermoplastic polymer at least in a surface of the abrasive cloth, the nanofibers of said surface of the abrasive cloth being formed of a napped surface of said nanofibers,
the nanofibers having a number average single fiber fineness of all nanofibers in the abrasive cloth of 0.8×10 −5 to 2×10 −4 dtex and the sum of fineness ratios of single fiber finenesses in the range of 0.8×10 −5 to 2×10 −4 dtex of 75% or more,
wherein stress at 10% elongation in a longitudinal direction is in the range of 10 to 200 N/cm width,
wherein 70% or more of the nanofibers in a single fiber fineness ratio falls within a width of 30 nm in a single fiber diameter difference, and
wherein a content of polyurethane is in the range of 20 to 60 wt. % of a fiber weight in the sheet material, and wherein the sheet material is impregnated with polyurethane.
2. The abrasive cloth according to claim 1 , wherein the sheet material is made of a nonwoven fabric.
3. The abrasive cloth according to claim 1 , wherein the sheet-like material is made of a woven fabric.
4. The abrasive cloth according to claim 1 , wherein the sheet-like material is made of a knitted fabric.
5. The abrasive cloth according to claim 1 , wherein a ratio S between a value of compressive elasticity of the sheet material under a load of 0.1 kg/cm 2 and that under a load of 0.5 kg/cm 2 is 4.0 or less.
6. The abrasive cloth according to claim 1 , wherein an abrasion resistance coefficient of the sheet material is 50 mg or less.
7. The abrasive cloth according to claim 1 , wherein a surface roughness value of the sheet material is 100 μm or less.
8. The abrasive cloth according to claim 1 , wherein a surface hardness value of the sheet material is 20 or more.
9. The abrasive cloth according to claim 1 , wherein the sheet material is formed in such a way that nanofibers are laminated on a support.
10. The abrasive cloth according to claim 9 , wherein a thickness of the nanofiber laminated layer is 70% or less of a thickness of the whole abrasive cloth.
11. The abrasive cloth according to claim 1 , wherein the sheet material has a space inside thereof, and the space is impregnated with a polymeric elastomer.
12. The abrasive cloth according to claim 11 , wherein the polymeric elastomer is polyurethane.
13. The abrasive cloth according to claim 11 , wherein a content of the polymeric elastomer is in the range of 20 to 60 wt. % of a fiber weight of the sheet material.
14. An abrasive cloth comprising a sheet material comprising polyurethane and having nanofibers of various finenesses made by a melt spinning method of a thermoplastic polymer at least in a surface of the abrasive cloth, the nanofibers of said surface of the abrasive cloth being formed of a napped surface of said nanofibers,
the nanofibers having a number average single fiber fineness of all nanofibers in the abrasive cloth of 0.8×10 −5 to 2×10 −4 dtex and the sum of fineness ratios of single fiber finenesses in the range of 0.8×10 −5 to 2×10 −4 dtex of 75% or more,
wherein stress at 10% elongation in a longitudinal direction is in the range of 10 to 200 N/cm width,
wherein a ratio S between a value of compressive elasticity of the sheet material under a load of 0.1 kg/cm 2 and that under a load of 0.5 kg/cm 2 is 4.0 or less, and
wherein a content of polyurethane is in the range of 20 to 60 wt. % of a fiber weight in the sheet material, and wherein the sheet material is impregnated with polyurethane.