Method for Producing Temperature Resistant NonWovens

• US 20100267914A1
• Filed: 03/12/2010
• Published: 10/21/2010
• Est. Priority Date: 04/21/2009
• Status: Active Grant

• Current Assignee: ExxonMobil Chemical Patents Inc. (Exxon Mobil Corporation)
• Original Assignee: ExxonMobil Chemical Patents Inc. (Exxon Mobil Corporation)
• Inventors: Westwood, Alistair Duncan, Williams, Michael Glenn, Richeson, Galen Charles
• Granted Patent: US 9,168,718 B2
• Time in Patent Office: Days
• US Class Current: 526/348
• CPC Class Codes: A61F 13/4902 characterised by the elastic material
• CPC Class Codes: A61F 13/51464 being stretchable or elastomeric
• CPC Class Codes: B29C 48/05 Filamentary, e.g. strands
• CPC Class Codes: B32B 2250/20 All layers being fibrous or filamentary
• CPC Class Codes: B32B 2262/0253 Polyolefin fibres vinyl or acrylic copolymers B32B2262/0223 or B32B2262/0246
• CPC Class Codes: B32B 2262/12 Conjugate fibres, e.g. core/sheath or side-by-side
• CPC Class Codes: B32B 2262/14 Mixture of at least two fibres made of different materials
• CPC Class Codes: B32B 2307/306 Resistant to heat
• CPC Class Codes: B32B 2307/51 Elastic
• CPC Class Codes: B32B 2307/718 Weight, e.g. weight per square meter
• CPC Class Codes: B32B 2310/0887 using electron radiation, e.g. beta-rays
• CPC Class Codes: B32B 2410/00 Agriculture-related articles
• CPC Class Codes: B32B 2432/00 Cleaning articles, e.g. mops, wipes personal care B32B2555/00
• CPC Class Codes: B32B 2437/00 Clothing anti-ballistic clothing B32B2571/02
• CPC Class Codes: B32B 2439/70 Food packaging
• CPC Class Codes: B32B 2457/10 Batteries
• CPC Class Codes: B32B 2471/02 Carpets
• CPC Class Codes: B32B 2471/04 Mats
• CPC Class Codes: B32B 2509/00 Household appliances
• CPC Class Codes: B32B 2535/00 Medical equipment, e.g. bandage, prostheses, catheter medical patches B32B2556/00
• CPC Class Codes: B32B 2555/00 : Personal care
• CPC Class Codes: B32B 2605/00 : Vehicles
• CPC Class Codes: B32B 37/153 : at least one layer is extruded and immediately laminated while in semi-molten state
• CPC Class Codes: B32B 5/02 : characterised by structural features of a fibrous or filamentary layer layer formed of metallic wires B32B15/02; layer formed of natural mineral fibres B32B19/02; layer formed of wood fibres B32B21/02
• CPC Class Codes: B32B 5/022 : Non-woven fabric
• CPC Class Codes: B32B 5/024 : Woven fabric
• CPC Class Codes: B32B 5/04 : characterised by a layer being specifically extensible by reason of its structure or arrangement , e.g. by reason of the chemical nature of the fibres or filaments
• CPC Class Codes: B32B 5/06 : characterised by a fibrous or filamentary layer mechanically connected, e.g. by needling to another layer, e.g. of fibres, of paper
• CPC Class Codes: B32B 5/08 : the fibres or filaments of a layer being of different substances , e.g. conjugate fibres, mixture of different fibres
• CPC Class Codes: B32B 5/22 : characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed layer formed of natural mineral fibres or particles next to a foam layer B32B19/047, next to a layer made of particles B32B19/048, or next to a fibrous or filamentary layer B32B19/06; paper layer or cardboard layer next to a paper layer or cardboard layer B32B29/005, next to a foam layer B32B29/007, next to a fibrous or filamentary layer B32B29/02, or next to a particulate layer B32B29/04
• CPC Class Codes: B32B 5/26 : another layer next to it also being fibrous or filamentary relative arrangement of fibres or filaments of different layers B32B5/12
• CPC Class Codes: D04H 1/42 : characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
• CPC Class Codes: D04H 1/4291 : Olefin series
• CPC Class Codes: D04H 3/007 : Addition polymers
• CPC Class Codes: D04H 3/16 : with bonds between thermoplastic filaments produced in association with filament formation, e.g. immediately following extrusion

Abstract

Temperature resistant multilayer composites, methods for making same, and articles made therefrom. The method can include extruding one or more polyolefin polymers having a MFR from less than 90 dg/min through at least one die having a plurality of nozzles to form a plurality of continuous fibers, at least one die operating at a melt pressure from greater than 500 psi (3447 kPa) to form at least one elastic meltblown layer; adhering the at least one elastic meltblown layer to at least one extensible layer to form a multilayer composite; and at least partially crosslinking the elastic meltblown layer or the extensible layer or both.

Claims

1. A method for forming a temperature resistant multilayer composite, comprising:

extruding one or more polyolefin polymers having a MFR from less than 90 dg/min through at least one die having a plurality of nozzles to form a plurality of continuous fibers, at least one die operating at a melt pressure from greater than 500 psi (3.45 MPa) to form at least one elastic meltblown layer;

adhering the at least one elastic meltblown layer to at least one extensible layer to form a multilayer composite; and

at least partially crosslinking the elastic meltblown layer or the extensible layer or both.

2. The method of claim 1, wherein the elastic meltblown fabric is adhered to at least one face of a spunlace fabric having a basis weight within the range from 10 to 150 g/m².

3. The method of claim 1, wherein the extensible fabric comprises from greater than 10 wt %, by weight of the fabric, of a polyolefin.

4. The method of claim 1, further comprising passing the multilayer construction through a hydroentangling apparatus.

5. The method of claim 1, wherein the die is operating at a melt temperature from less than 280°

C.

6. The method of claim 1, wherein the components are melt blended in an apparatus where visbreaking agents are excluded.

7. The method of claim 1, wherein the polyolefin polymer is a propylene-α

-olefin copolymer having a comonomer-derived content within the range from 5 to 35 wt % by weight of the copolymer.

8. The method of claim 1, wherein the construction has a peak force value (ASTM 2261-07a) within the range from 1 and 2 lbs at an Elongation of greater than 1000%.

9. The method of claim 1, wherein the number of continuous fibers per square inch of the elastic meltblown fabric is within the range from 20 to 500 fibers/in².

10. The method of claim 1, wherein the elastic meltblown fabric possesses an MD Elongation from less than 100% and a CD Elongation from greater than 100%.

11. The method of claim 1, wherein the extensible fabric comprises at least one layer of a spunlace fabric having a basis weight within the range of from 10 to 150 g/m² and comprising from greater than 10 wt %, by weight of the fabric, of a polyolefin.

12. The method of claim 1, wherein the extensible fabric has an Ultimate Elongation from greater than 200%.

13. The method of claim 1, wherein the multilayer construction or its individual layers are not mechanically stretched or oriented.

14. The method of claim 1, wherein styrenic block copolymers, as a fabric layer or component of a fabric layer, are substantially absent.

15. An absorbent article comprising the multilayer construction according to claim 1.

16. The article of claim 15, wherein the article is selected from baby diapers, pullups, training pants, adult incontinence briefs and diapers, panty liners, sanitary napkins, medical garments, and bandages.

17. A method for forming a temperature resistant multilayer composite, comprising:

extruding one or more elastic or extensible resins through one or more dies having a plurality of nozzles to form a first plurality of continuous fibers;

extruding one or more inelastic resins or extensible through one or more dies simultaneously or nearly simultaneously with the one or more elastic resins to form a second plurality of continuous fibers; and

crosslinking the extruded resin using electron beam radiation having an e-beam dose of about 200 kGy or less.

18. The method of claim 17, wherein the e-beam dose is about 100 kGy.

19. The method of claim 17, wherein the e-beam dose ranges of from 40 kGy to about 60 kGy.

20. An absorbent article comprising the cured multilayer construction according to claim 17.