Resilient absorbent coform nonwoven web

Patent metadata

Field	Value
Publication number	US-2016228596-A1
Application number	US-201615134608-A
Country	US
Kind code	A1
Filing date	Apr 21, 2016
Priority date	Dec 21, 2009
Publication date	Aug 11, 2016
Grant date	—

Abstract

A resilient coform nonwoven web that contains a matrix of meltblown fibers and an absorbent material is provided. The meltblown fibers may constitute from 45 wt % to about 99 wt % of the web and the absorbent material may constitute from about 1 wt % to about 55 wt % of the web. The meltblown fibers may be formed from a thermoplastic composition that contains at least one propylene/α-olefin copolymer having a propylene content of from about 60 mole % to about 99.5 mole % and an α-olefin content of from about 0.5 mole % to about 40 mole %. The copolymer may have a density of from about 0.86 to about 0.90 grams per cubic centimeter and the thermoplastic composition may have a melt flow rate of from about 200 to about 6000 grams per 10 minutes, determined at 230° C. in accordance with ASTM Test Method D1238-E. The coform web may be imparted with a three-dimensional texture by, for example, using a three-dimensional forming surface. As one example, the resilient coform web is suitable for use as a component in the absorbent core of a personal care absorbent product.

First claim

What is claimed is:

1 . A resilient coform nonwoven web comprising a matrix of meltblown fibers and an absorbent material, wherein the meltblown fibers constitute from 45 wt % to about 99 wt % of the web and the absorbent material constitutes from about 1 wt % to about 55 wt % of the web, and further wherein the meltblown fibers being formed from a thermoplastic composition that contains at least one propylene/α-olefin copolymer having a propylene content of from about 60 mole % to about 99.5 mole % and an α-olefin content of from about 0.5 mole % to about 40 mole %, wherein the copolymer further has a density of from about 0.86 to about 0.90 grams per cubic centimeter and the composition has a melt flow rate of from about 120 to about 6000 grams per 10 minutes, determined at 230° C. in accordance with ASTM Test Method D1238-E.

2 . The resilient coform nonwoven web of claim 1 , wherein the α-olefin includes ethylene.

3 . The resilient coform nonwoven web of claim 1 , wherein propylene constitutes from about 85 mole % to about 98 mole % of the copolymer and the α-olefin constitutes from about 2 mole % to about 15 mole % of the copolymer.

4 . The resilient coform nonwoven web of claim 1 , wherein the copolymer has a density of from about 0.861 to about 0.89 grams per cubic centimeter, and preferably from about 0.862 to about 0.88 grams per cubic centimeter.

5 . The resilient coform nonwoven web of claim 1 , wherein the propylene copolymer is single-site catalyzed.

6 . The resilient coform nonwoven web of claim 1 , wherein the melt flow rate of the composition is from about 170 to about 1500 grams per 10 minutes.

7 . The resilient coform nonwoven web of claim 1 , wherein the thermoplastic composition comprises from about 0.001 wt % to about 15 wt % of a surfactant.

8 . The resilient coform nonwoven web of claim 1 , wherein the propylene/α-olefin copolymer constitutes from about 15 wt % to about 99.9 wt % of the thermoplastic composition.

9 . The coform nonwoven web of claim 1 , wherein the absorbent material comprises pulp fibers.

10 . The resilient coform nonwoven web of claim 1 , wherein the absorbent material comprises superabsorbent polymer particles or superabsorbent polymer fibers.

11 . The resilient coform nonwoven web of claim 1 , wherein the meltblown fibers constitute from 50 wt % to about 90 wt % of the web and the absorbent material constitutes from about 10 wt % to about 50 wt % of the web.

12 . The resilient coform nonwoven web of claim 1 , wherein the web defines an exterior surface having a three-dimensional texture that includes a plurality of peaks and valleys.

13 . An absorbent personal care article comprising the resilient coform nonwoven web of claim 1 .

14 . An absorbent personal care article comprising a body-side liner, an absorbent core comprising the resilient coform nonwoven web of claim 1 , and a garment-side baffle.

15 . A method of forming a resilient coform nonwoven web, the method comprising:
merging together a stream of an absorbent material with a stream of meltblown fibers to form a composite stream, wherein the meltblown fibers constitute from 45 wt % to about 99 wt % of the web and the absorbent material constitutes from about 1 wt % to about 55 wt % of the web, and further wherein the meltblown fibers are formed from a thermoplastic composition that contains at least one propylene/α-olefin copolymer having a propylene content of from about 60 mole % to about 99.5 mole % and an α-olefin content of from about 0.5 mole % to about 40 mole %, wherein the copolymer further has a density of from about 0.86 to about 0.90 grams per cubic centimeter and the composition has a melt flow rate of from about 120 to about 6000 grams per 10 minutes, determined at 230° C. in accordance with ASTM Test Method D1238-E; and thereafter, collecting the composite stream on a forming surface to form a resilient coform nonwoven web.

16 . The method of claim 15 , wherein the melt flow rate of the composition is from about 170 to about 1500 grams per 10 minutes.

17 . The method of claim 15 , wherein the thermoplastic composition comprises from about 0.001 wt % to about 15 wt % of a surfactant.

18 . The method of claim 15 , wherein the stream of absorbent material is merged together with first and second streams of meltblown fibers.

19 . The method of claim 15 , wherein the first stream and second stream of meltblown fibers are supplied from respective first and second die heads, each of which is oriented at an angle of from about 45° to 55° relative to a plane tangent to the die heads.

20 . The method of claim 15 , wherein the web defines an exterior surface having a three-dimensional texture that includes a plurality of peaks and valleys.

Assignees

• Kimberly Clark Co

Inventors

• Jackson David M

Classifications

• D04H1/407 Primary

  containing absorbing substances, e.g. activated carbon · CPC title

• A61L15/60

  Liquid-swellable gel-forming materials, e.g. super-absorbents · CPC title

• A61F13/15658

  Forming continuous, e.g. composite, fibrous webs, e.g. involving the application of pulverulent material on parts thereof · CPC title

• A61F13/538

  characterised by specific fibre orientation or weave · CPC title

• A61L15/24 Primary

  Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds; Derivatives thereof {(A61L15/225 takes precedence)} · CPC title