Crimped conjugated fiber and nonwoven fabric comprising the same

Patent metadata

Field	Value
Publication number	US-10077518-B2
Application number	US-200913121978-A
Country	US
Kind code	B2
Filing date	Oct 23, 2009
Priority date	Oct 29, 2008
Publication date	Sep 18, 2018
Grant date	Sep 18, 2018

Abstract

A crimped conjugated fiber having a cross-sectional configuration wherein: a cross section of the fiber comprises at least a portion (a) comprising a propylene polymer (A) and a portion (b) comprising a propylene polymer (B), the mass ratio of the portion (a) and the portion (b) is in the range of 10:90 to 55:45, the propylene polymer (A) has Mz/Mw (A) and the propylene polymer (B) has Mz/Mw (B) wherein the difference thereof is in the range of 0.30 to 2.2, the absolute value difference of the melting points of the propylene polymer (A) and the propylene polymer (B) is in the range of 0 to 10° C., and the ratio of MFR (A) of the propylene polymer (A) to MFR (B) of the propylene polymer (B) is in the range of 0.8 to 1.2. A nonwoven fabric of crimped conjugated fiber is also provided.

First claim

The invention claimed is:

1. A crimped conjugated fiber having a cross-sectional configuration wherein:
a cross section of the fiber comprises at least a portion (a) and a portion (b),
the mass ratio of the portion (a) and the portion (b) [(a):(b)] is in the range of 10:90 to 55:45,
the portion (a) comprises a propylene polymer (A) and the portion (b) comprises a propylene polymer (B),
the propylene polymer (A) has Mz/Mw (A) and the propylene polymer (B) has Mz/Mw (B) wherein the difference thereof [Mz/Mw (A)−Mz/Mw (B): ΔMz/Mw] is in the range of 0.30 to 2.2,
the propylene polymer (A) has a melting point [Tm (A)] and the propylene polymer (B) has a melting point [Tm (B)] wherein the absolute value of the difference of the melting points is in the range of 0 to 5° C., and
the ratio of MFR (A) of the propylene polymer (A) to MFR (B) of the propylene polymer (B) is in the range of 0.8 to 1.2.

2. The crimped conjugated fiber according to claim 1 , wherein the propylene polymer (A) has Mw/Mn (A) and the propylene polymer (B) has Mw/Mn (B) wherein the absolute value of the difference thereof [|Mw/Mn (A)−Mw/Mn (B)|:|ΔMw/Mn|] is not more than 1.5.

3. The crimped conjugated fiber according to claim 1 , wherein the crimped conjugated fiber has an eccentric core-sheath configuration in which the portion (a) is a core (a′) and the portion (b) is a sheath (b′).

4. The crimped conjugated fiber according to claim 3 , wherein the mass ratio of the core (a′) and the sheath (b′) [(a′):(b′)] is in the range of 10-30:90-70.

5. The crimped conjugated fiber according to claim 1 , wherein the propylene polymer (A) and the propylene polymer (B) are both propylene homopolymers.

6. The crimped conjugated fiber according to claim 1 , wherein the propylene polymer (A) and the propylene polymer (B) are both propylene/α-olefin random copolymers.

7. A nonwoven fabric comprising the crimped conjugated fiber described in claim 1 .

8. The nonwoven fabric according to claim 7 , wherein the crimped conjugated fiber is thermally fusion bonded by embossing.

9. The crimped conjugated fiber according to claim 2 , wherein the propylene polymer (A) and the propylene polymer (B) are both propylene homopolymers.

10. The crimped conjugated fiber according to claim 2 , wherein the propylene polymer (A) and the propylene polymer (B) are both propylene/α-olefin random copolymers.

11. A nonwoven fabric comprising the crimped conjugated fiber described in claim 2 .

12. A nonwoven fabric comprising the crimped conjugated fiber described in claim 3 .

13. A nonwoven fabric comprising the crimped conjugated fiber described in claim 4 .

14. The nonwoven fabric according to claim 11 , wherein the crimped conjugated fiber is thermally fusion bonded by embossing.

15. The nonwoven fabric according to claim 12 , wherein the crimped conjugated fiber is thermally fusion bonded by embossing.

16. The nonwoven fabric according to claim 13 , wherein the crimped conjugated fiber is thermally fusion bonded by embossing.

Assignees

• Morimoto Hisashi
• Masuda Kazuhiko
• Mitsui Chemicals Inc

Inventors

• Morimoto Hisashi
• Masuda Kazuhiko

Classifications

• Y10T442/629

  Composite strand or fiber material · CPC title

• Y10T428/2924

  Composite · CPC title

• D04H3/14 Primary

  with bonds between thermoplastic yarns or filaments produced by welding · CPC title

• D01D5/22

  with a crimped or curled structure; with a special structure to simulate wool (producing crimped or curled effects in filaments or threads after formation D02G1/00) · CPC title

• D01F8/06

  with at least one polyolefin as constituent · CPC title