Polymers for use in fibers and nonwoven fabrics, articles thereof, and composites thereof

Patent metadata

Field	Value
Publication number	US-11261544-B2
Application number	US-201816486521-A
Country	US
Kind code	B2
Filing date	Mar 7, 2018
Priority date	Mar 17, 2017
Publication date	Mar 1, 2022
Grant date	Mar 1, 2022

Abstract

An ethylene/alpha-olefin interpolymer suitable for use in fibers and nonwovens having a density of from 0.911 to 0.939 g/cc, a Brookfield viscosity of less than or equal to 50,000 cP, and a molecular weight distribution (M w,cc /M n,cc ) of 1.8 to 3.5, and articles thereof.

First claim

We claim:

1. An ethylene/alpha-olefin interpolymer suitable for use in fibers and nonwovens having a density of from 0.911 to 0.939 g/cc, a Brookfield viscosity of less than or equal to 50,000 cP, and a molecular weight distribution (M w,cc /M n,cc ) of 1.8 to 3.5, and an M zcc /M ncc is less than 5.25.

2. The interpolymer of claim 1 , wherein the ethylene/alpha-olefin interpolymer has a weight fraction (w) of molecular weight greater than 10 5 g/mole, based on the total weight of interpolymer, as determined by conventional gel permeation chromatography, of less than 2.5%.

3. The interpolymer of claim 1 , wherein the ethylene/alpha-olefin interpolymer has a comonomer distribution breadth index of greater than 50%, or alternatively, from 50% to 98%, or alternatively, 50% to 85%.

4. A meltblown nonwoven comprising an ethylene/alpha-olefin interpolymer, wherein the ethylene/alpha-olefin interpolymer has:
a density of from 0.911 to 0.939 g/cc,
a Brookfield viscosity of less than or equal to 50,000 cP, and
a molecular weight distribution (M w,cc /M n,cc ) of 1.8 to 3.5, and
an M zcc /M ncc of less than 5.25, or alternatively, less than 4.0 or 3.5.

5. The meltblown nonwoven of claim 4 , wherein the ethylene/alpha-olefin interpolymer has a weight fraction (w) of molecular weight greater than 10 5 g/mole, based on the total weight of interpolymer, and as determined by conventional gel permeation chromatography, of less than 2.5%.

6. The meltblown nonwoven of claim 4 , wherein the ethylene/alpha-olefin interpolymer has a comonomer distribution breadth index of greater than 0%.

7. A composite structure comprising the meltblown nonwoven of claim 4 .

8. The composite structure of claim 7 , wherein the composite structure further comprises one or more spunbond nonwovens.

9. A composite structure having a S a M b S c configuration, wherein S is a spunbond nonwoven, M is the meltblown nonwoven of 4 , and a, b, and c are the number of layers and are independent integers ranging from 1 to 5.

10. The composite structure of claim 9 , wherein the spunbond nonwoven is formed from bicomponent fibers having a sheath/core structure, wherein the sheath comprises polyethylene and the core comprises polypropylene.

11. The composite structure of claim 9 , wherein the spunbond nonwoven is formed from monocomponent fibers, wherein the monocomponent fibers comprise polyethylene.

Assignees

• Dow Global Technologies Llc

Inventors

• Shah Viraj
• Lin Yijian
• Wevers Ronald
• Cong Rongjuan
• Demirors Mehmet

Classifications

• D04H1/56

  in association with fibre formation, e.g. immediately following extrusion of staple fibres · CPC title

• D04H1/4291

  Olefin series · CPC title

• C08F4/65912

  in combination with an organoaluminium compound · CPC title

• D04H3/16

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

• C08F2500/06

  Comonomer distribution, e.g. normal, reverse or narrow · CPC title