Breathable, cloth-like film/nonwoven composite

• US 5,695,868 A
• Filed: 11/25/1996
• Issued: 12/09/1997
• Est. Priority Date: 12/17/1993
• Status: Expired due to Term

• Current Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Original Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Inventors: McCormack, Ann Louise
• Primary Examiner(s): Sweet, Mark D.
• Application Number:
  US08/755,692
• Time in Patent Office: 379 Days
• Field of Search: 428/283, 428/288, 428/290, 428/516, 428/688, 524/427, 604/370, 604/384
• US Class Current: 442/389
• CPC Class Codes: B32B 2038/0028 Stretching, elongating
• CPC Class Codes: B32B 2250/242 All polymers belonging to those covered by group B32B27/32
• CPC Class Codes: B32B 2262/0253 Polyolefin fibres
• CPC Class Codes: B32B 2262/14 Mixture of at least two fibres made of different materials
• CPC Class Codes: B32B 2270/00 Resin or rubber layer containing a blend of at least two different polymers
• CPC Class Codes: B32B 2307/724 Permeability to gases, adsorption
• CPC Class Codes: B32B 2307/7265 Non-permeable
• CPC Class Codes: B32B 2323/046 LDPE, i.e. low density polyethylene
• CPC Class Codes: B32B 2323/10 Polypropylene
• CPC Class Codes: B32B 2555/02 Diapers or napkins
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/12 next to a fibrous or filamentary layer
• CPC Class Codes: B32B 27/20 using fillers, pigments, thixotroping agents
• CPC Class Codes: B32B 27/32 comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• CPC Class Codes: B32B 37/153 at least one layer is extruded and immediately laminated while in semi-molten state
• CPC Class Codes: B32B 38/0032 increasing porosity B32B38/04 takes precedence
• CPC Class Codes: B32B 5/022 Non-woven fabric
• CPC Class Codes: B32B 5/24 one layer being a fibrous or filamentary layer
• CPC Class Codes: B32B 7/12 using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: Y10T 428/31913 Monoolefin polymer
• CPC Class Codes: Y10T 442/668 : Separate nonwoven fabric layers comprise chemically different strand or fiber material
• CPC Class Codes: Y10T 442/673 : Including particulate material other than fiber
• CPC Class Codes: Y10T 442/678 : Olefin polymer or copolymer sheet or film [e.g., polypropylene, polyethylene, ethylene-butylene copolymer, etc.]

Abstract

Disclosed herein is a breathable film and a breathable, cloth-like film/nonwoven composite made from the breathable film which is stretch-thinned and bonded to a fibrous polyolefin nonwoven web. Certain thermoplastic films such as, for example, linear low density polyethylene films are difficult to thermally bond to, for example, polypropylene nonwoven webs due to the incompatibility of the two polymers. The present invention incorporates a bonding agent into one or both of the two layers thereby making it easier to thermally bond the two layers together. Processes for forming the various composite are also disclosed.

Claims

1. A breathable film/nonwoven laminate comprising:

a film formed from a blend including, on a dry weight basis, based upon the total weight of the film, from about 10 to about 68 percent of a predominately linear polyolefin polymer, from about 30 to about 80 percent of a filler and from about 2 to about 20 percent of a bonding agent, said film having a water vapor transmission rate of at least 100 g/m² /24 hours, and

a fibrous polyolefin nonwoven web bonded directly to said film to form a laminate, said laminate having a peel strength of at least 24 grams.

2. The laminate of claim 1 wherein said predominately linear polyolefin polymer is linear low density polyethylene.

3. The laminate of claim 1 wherein said filler is calcium carbonate.

4. The laminate of claim 1 wherein said film is a stretched film having a weight per unit area of less than 35 g/m².

5. The laminate of claim 1 wherein said film is a stretched film having a weight per unit area of less than about 18 g/m².

6. The laminate of claim 1 wherein said fibrous polyolefin nonwoven web is a polypropylene nonwoven web.

7. The laminate of claim 1 wherein said fibrous polyolefin nonwoven web contains bicomponent fibers with a polyolefin as a component of said bicomponent fibers.

8. The laminate of claim 1 wherein a second fibrous polyolefin nonwoven web is bonded to said film on a side of said film opposite said fibrous polyolefin nonwoven web.

9. A film/nonwoven laminate comprising:

a film layer including, on a dry weight basis, based upon the total weight of the film, from about 30 to about 80 percent of a filler and from about 20 to about 70 percent polyolefin polymer, and

a fibrous nonwoven web bonded directly to said film layer by a plurality of fibers within said fibrous nonwoven web which contain a polyolefin polymer and a bonding agent, said polyolefin polymer and said bonding agent forming at least a portion of an exterior surface of said fibers to create a peel strength between said film layer and said fibrous nonwoven web of at least 24 grams.