Laminated structures

• US 6,887,941 B2
• Filed: 08/26/2003
• Issued: 05/03/2005
• Est. Priority Date: 12/29/2000
• Status: Active Grant

• Current Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Original Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Inventors: Zhou, Peiguang
• Primary Examiner(s): Nutter, Nathan M.
• Application Number:
  US10/648,458
• Publication Number:
  US 20040038058A1
• Time in Patent Office: 616 Days
• Field of Search: 525/191, 525/240, 428/58, 442/149, 442/150, 442/151, 442/155, 156/327, 156/358
• US Class Current: 525/191
• CPC Class Codes: B32B 2037/1215 Hot-melt adhesive
• CPC Class Codes: B32B 2305/20 in the form of a non-woven mat
• CPC Class Codes: B32B 2307/51 Elastic
• CPC Class Codes: B32B 25/04 comprising rubber as the main or only constituent of a layer, which is next to another layer of the same or of a different material next to a layer of a particular substance B32B9/043; next to a bituminous or tarry layer B32B11/044; next to a water setting substance layer B32B13/042; next to a metal layer B32B15/06; next to a glass layer B32B17/063; next to a layer formed of natural mineral fibres or particles B32B19/043; next to a wood layer B32B21/045; next to a cellulosic plastic layer B32B23/046
• CPC Class Codes: B32B 37/12 characterised by using adhesives
• 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 5/04 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 5/26 another layer next to it also being fibrous or filamentary relative arrangement of fibres or filaments of different layers B32B5/12
• CPC Class Codes: B32B 7/12 using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: C08L 2205/02 containing two or more polymers of the same C08L -group
• CPC Class Codes: C08L 2207/14 Amorphous or atactic polypropylene
• CPC Class Codes: C08L 23/10 Homopolymers or copolymers of propene
• CPC Class Codes: C08L 2666/04 Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof
• CPC Class Codes: C09J 123/02 not modified by chemical after-treatment
• CPC Class Codes: C09J 123/10 Homopolymers or copolymers of propene
• CPC Class Codes: C09J 123/12 Polypropene
• CPC Class Codes: C09J 123/14 Copolymers of propene C09J123/16 takes precedence
• CPC Class Codes: C09J 123/142 at least partially crystalline copolymers of propene with other olefins
• CPC Class Codes: C09J 123/20 having four to nine carbon atoms
• CPC Class Codes: C09J 153/00 Adhesives based on block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Adhesives based on derivatives of such polymers
• CPC Class Codes: C09J 153/02 : Vinyl aromatic monomers and conjugated dienes
• CPC Class Codes: Y10T 428/192 : Sheets or webs coplanar
• CPC Class Codes: Y10T 428/31855 : Of addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 442/2738 : Coating or impregnation intended to function as an adhesive to solid surfaces subsequently associated therewith
• CPC Class Codes: Y10T 442/2746 : Heat-activatable adhesive
• CPC Class Codes: Y10T 442/2754 : Pressure-sensitive adhesive
• CPC Class Codes: Y10T 442/2787 : Coating or impregnation contains a vinyl polymer or copolymer

Abstract

Hot-melt, pressure-sensitive adhesive compositions of amorphous polyalphaolefin and crystalline polypropylene have improved bond strength over the amorphous polyalphaolefin alone. The adhesive compositions improve dynamic shear strength, dynamic peel strength, as well as static peel strength. The adhesive compositions are particularly suitable for use in absorbent articles.

Claims

1. A laminated structure comprising:

a first substrate;

a second substrate; and

a pressure sensitive hot melt adhesive bonding the first substrate and the second substrate to one another, wherein the adhesive includes an amorphous polyalphaolefin and a crystalline polypropylene having a degree of crystallinity of at least about 40%, the amorphous polyalphaolefin comprising a butene-1 terpolymer with ethylene and propylene and having a number-average molecular weight between about 5,000 and about 30,000 and a weight-average molecular weight between about 20,000 and about 60,000, the crystalline polypropylene having a number-average molecular weight between about 20,000 and about 300,000, and wherein the adhesive composition has a melt index between about 200 and about 2000 grams per 10 minutes.

2. The laminated structure of claim 1, comprising between about 70% and about 90% of the amorphous polyalphaolefin, and between about 10% and about 30% of the crystalline polypropylene.

3. The laminated structure of claim 1, comprising between about 73% and about 87% of the amorphous polyalphaolefin, and between about 13% and about 27% of the crystalline polypropylene.

4. The laminated structure of claim 1, comprising between about 75% and about 85% of the amorphous polyalphaolefin, and between about 15% and about 25% of the crystalline polypropylene.

5. The laminated structure of claim 1, wherein the degree of crystallinity of the crystalline polypropylene is at least about 60%.

6. The laminated structure of claim 1, wherein the degree of crystallinity of the crystalline polypropylene is at least about 80%.

7. The laminated structure of claim 1, wherein the amorphous polyalphaolefin has a weight-average molecular weight between about 25,000 and about 50,000.

8. The laminated structure of claim 1, wherein the adhesive composition has a melt index between about 400 and about 1800 grams per 10 minutes.

9. The laminated structure of claim 1, wherein the adhesive composition has a melt index between about 500 and about 1500 grams per 10 minutes.

10. The laminated structure of claim 1, wherein the butene-1 terpolymer comprises betewen about 20% and about 65% by weight butene-1.

11. The laminated structure of claim 1, wherein the butene-1 terpolymer comprises betewen about 30% and about 55% by weight butene-1.

12. The laminated structure of claim 1, wherein the crystalline polypropylene comprises at least one of the group consisting of isotactic polypropylene, syndiotactic polypropylene, and combinations thereof.

13. The laminated structure of claim 1, wherein the first and second substrates are each part of a single substrate.

14. The laminated structure of claim 1, wherein each of the first and second substrates is selected from the group consisting of:

nonwoven material, woven material, and film.

15. The laminated structure of claim 1, wherein at least one of the first and second substrates comprises at least one of the group consisting of cellulosic material, thermoplastic material, and combinations thereof.

16. The laminated structure of claim 1, wherein at least one of the first and second substrates comprises at least one of the group consisting of a necked-bonded laminate, a polypropylene spunbonded layer, and a polyethylene layer in combination with a polypropylene spunbonded layer.

17. The laminated structure of claim 1, wherein the first and second substrates each comprise a neck-bonded laminate.

18. The laminated structure of claim 1, wherein the first substrate comprises a film and the second substrate comprises a spunbond web.

19. The laminated structure of claim 1, wherein the adhesive composition is melt-blown onto at least one of the first and second substrates.

20. The laminated structure of claim 1, wherein the adhesive composition is applied to at least one of the first and second substrates in a swirl pattern.

21. The laminated structure of claim 1, wherein the adhesive composition is applied to at least one of the first and second substrates in a concentration of between about 1 gram per square meter and about 50 grams per square meter.

22. The laminated structure of claim 1, wherein the adhesive composition is applied to at least one of the first and second substrates in a concentration of between about 5 grams per square meter and about 20 grams per square meter.

23. The laminated structure of claim 1, wherein the laminated structure has a dynamic shear bond strength greater than a dynamic shear material strength.

24. The laminated structure of claim 1, wherein the laminated structure has a static peel bond strength greater than a static peel material strength.

25. A laminated structure comprising:

a first substrate;

a second substrate; and

a pressure sensitive hot melt adhesive bonding the first substrate and the second substrate to one another, wherein the adhesive includes an amorphous polyalphaolefin and a crystalline polypropylene having a degree of crystallinity of at least about 40%, the amorphous polyalphaolefin comprising a butene-1 copolymer and having a number-average molecular weight between about 5,000 and about 30,000 and a weight-average molecular weight between about 20,000 and about 60,000, the crystalline polypropylene having a number-average molecular weight between about 10,000 and 100,000 and a weight-average molecular weight between about 20,000 and about 300,000, and wherein the adhesive composition has a melt index between about 200 and about 2000 grams per 10 minutes.

26. The laminated structure of claim 25, comprising between about 70% and about 90% of the amorphous polyalphaolefin, and between about 10% and about 30% of the crystalline polypropylene.

27.The laminated structure of claim 25, comprising between about 73% and about 87% of the amorphous polyalphaolefin, and between about 13% and about 27% of the crystalline polypropylene.

27. The laminated structure of claim 25, comprising between about 75% and about 85% of the amorphous polyalphaolefin, and between about 15% and about 25% of the crystalline polypropylene.

28. The laminated structure of claim 25, wherein the degree of crystallinity of the crystalline polypropylene is at least about 60%.

29. The laminated structure of claim 25, wherein the degree of crystallinity of the crystalline polypropylene is at least about 80%.

30. The laminated structure of claim 25, wherein the amorphous polyalphaolefin has a weight-average molecular weight between about 25,000 and about 50,000.

31. The laminated structure of claim 25, wherein the adhesive composition has a melt index between about 400 and about 1800 grams per 10 minutes.

32. The laminated structure of claim 25, wherein the adhesive composition has a melt index between about 500 and about 1500 grams per 10 minutes.

33. The laminated structure of claim 25, wherein the butene-1 copolymer comprises between about 25% and about 65% by weight butene-1, and a balance of a comonomer selected from the group consisting of ethylene, propylene, and combinations thereof.

34. The laminated structure of claim 25, wherein the butene-1 copolymer comprises between about 30% and about 55% by weight butene-1, and a balance of a comonomer selected from the weight butene-1, and a balance of a comonomer selected from the group consisting of ethylene, propylene, and combinations thereof.

35. The laminated structure of claim 25, wherein the crystalline polypropylene comprises at least one of the group consisting of isotactic polypropylenem syndiotactic polypropylene, and combinations thereof.

36. The laminated structure of claim 25, wherein the first and second substrates are each part of a single substrate.

37. The laminated structure of claim 25, wherein each of the first and second substrates is selected from the group consisting of:

nonwoven material, woven material, and film.

38. The laminated structure of claim 25, wherein at least one of the first and second substrated comprises at least one of the group consisting of cellulosic material, thermoplastic material, and combinations thereof.

39. The laminated structure of claim 25, wherein at least one of the first and second substrates comprises at least one of the group consisting of a necked-bonded laminate, a polypropylene spunbonded layer, and a polyethylene layer in combination with a polypropylene spunbonded layer.

40. The laminated structure of claim 25, wherein the first and second substrates each comprise a neck-bonded laminate.

41. The laminated structure of claim 25, wherein the first substrate comprises a film and the second substrate comprises a spunbond web.

42. The laminated structure of claim 25, wherein the adhesive composition is melt-blown onto at least one of the first and second substrates.

43. The laminated structure of claim 25, wherein the adhesive composition is applied to at least one of the first and second substrates in a swirl pattern.

44. The laminated structure of claim 25, wherein the adhesive composition is applied to at least one of the first and second substrates in a concentration of between about 1 gram per square meter and about 50 grams per square meter.

45. The laminated structure of claim 25, wherein the adhesive composition is applied to at least one of the first and second substrates in a concentration of between about 5 grams per square meter and about 20 grams per square meter.

46. The laminated structure of claim 25, wherein the laminated structure has a dynamic shear bond strength greater than a dynamic shear material strength.

47. The laminated structure of claim 25, wherein the laminated structure has a static peel bond strength greater than a static peel material strength.