Non-woven polypropylene fabric

Patent metadata

Field	Value
Publication number	US-9587334-B2
Application number	US-201113574085-A
Country	US
Kind code	B2
Filing date	Jan 20, 2011
Priority date	Jan 21, 2010
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

Provided is a non-woven fabric produced by using a polypropylene-based resin composition containing a specific low-crystalline polypropylene. The non-woven fabric is a non-woven fabric obtained by achieving reductions in denier values of fibers, the non-woven fabric being excellent in dispersibility of the fibers.

First claim

The invention claimed is:

1. A non-woven fabric, is obtained by a process comprising producing a non-woven fabric from a polypropylene-based resin composition,
wherein the polypropylene-based resin composition comprises a low-crystalline polypropylene and a high-crystalline polypropylene;
the polypropylene-based resin composition comprises the low-crystalline polypropylene at a content of from 5 to 50 mass % with reference to a total of the low-crystalline polypropylene and the high-crystalline polypropylene;
the polypropylene-based resin composition has a melt flow rate of from 500 to 2,000 g/10 min and a melting endotherm ΔH measured by DSC of from 50 to 95 J/g; and
the low-crystalline polypropylene satisfies (a) to (f):
(a) [mmmm] is from 20 to 60 mol %;
(b) [rrrr/(1-mmmm)]≦0.1;
(c) [rmrm]>2.5 mol %;
(d) [mm]×[rr]/[mr] 2 ≦2.0;
(e) weight-average molecular weight (Mw) is from 10,000 to 200,000; and
(f) molecular weight distribution (Mw/Mn)<4
wherein the low-crystalline propylene homo-polymer, and
wherein the process comprises a meltdown method.

2. A non-woven fabric laminate, comprising the non-woven fabric of claim 1 .

3. A fiber product, comprising the non-woven fabric of claim 1 .

4. A fiber product, comprising the non-woven fabric laminate of claim 2 .

5. A hygienic material, comprising the non-woven fabric of claim 1 .

6. The hygienic material of claim 5 , wherein the hygienic material is a paper diaper.

7. The non-woven fabric of claim 1 , wherein [mmmm] of the low-crystalline polypropylene is from 30 to 50 mol %.

8. The non-woven fabric of claim 1 , wherein [rrrr]/(1-[mmmm]) of the low-crystalline polypropylene is 0.05 or less.

9. The non-woven fabric of claim 1 , wherein an average fiber diameter of the fabric is about 1.0 μm or less.

10. The non-woven fabric laminate of claim 2 , comprising:
a meltblown non-woven fabric, and
a first spunbound non-woven fabric, laminated with the meltblown non-woven fabric.

11. The non-woven fabric laminate of claim 10 , further comprising:
a second spunbound non-woven fabric layer, on an opposite side of the meltblown non-woven fabric layer from the first spunbound non-woven fabric layer.

12. The non-woven fabric laminate of claim 11 ,
wherein a basis weight of the laminate is from 7 to 100 g/m 2 .

13. A process for producing the non-woven fabric of claim 1 , comprising:
producing a non-woven fabric from a polypropylene-based resin composition,
wherein the polypropylene-based resin composition comprises a low-crystalline polypropylene and a high-crystalline polypropylene;
the polypropylene-based resin composition comprises the low-crystalline polypropylene at a content of from 5 to 50 mass % with reference to a total of the low-crystalline polypropylene and the high-crystalline polypropylene;
the polypropylene-based resin composition has a melt flow rate of from 500 to 2,000 g/10 min and a melting endotherm ΔH measured by DSC of from 50 to 95 J/g; and
the low-crystalline polypropylene satisfies (a) to (f):
(a) [mmmm] is from 20 to 60 mol %;
(b) [rrrr/(1-mmmm)]≦0.1;
(c) [rmrm]>2.5 mol %;
(d) [mm]×[rr]/[mr] 2 ≦2.0;
(e) weight-average molecular weight (Mw) is from 10,000 to 200,000; and
(f) molecular weight distribution (Mw/Mn)<4,
wherein the low-crystalline polypropylene is a propylene homo-polymer, and
wherein the producing comprises producing by a meltdown method.

14. A process of producing a non-woven fabric laminate, comprising:
producing a non-woven fabric by the process of claim 13 , and
laminating the non-woven fabric with another fabric layer, thereby obtaining the laminate.

15. The process of claim 13 , wherein
a melting temperature of the resin is from 220 to 270° C.,
a single-hole discharge amount of from 0.1 to 0.5 g/min,
a temperature of the heated gas flow of from 250 to 280° C., and
a flow rate of the heated gas flow of from 200 to 600 m 3 /hr.

Assignees

• Takebe Tomoaki
• Minami Yutaka
• Koori Yohei
• Idemitsu Kosan Co

Inventors

• Takebe Tomoaki
• Minami Yutaka
• Koori Yohei

Classifications

• Y10T428/2915

  including textile, cloth or fabric · CPC title

• C08F110/06

  Propene · CPC title

• Y10T442/60

  Nonwoven fabric [i.e., nonwoven strand or fiber material] · CPC title

• C08F2500/12

  Melt flow index or melt flow ratio · CPC title

• Y10T442/609

  Cross-sectional configuration of strand or fiber material is specified · CPC title