Laminated structures having modified rubber-based adhesives
View Patent ↗Elastic attachment adhesive compositions of conventional rubber-based construction adhesive and a crystalline polymer have improved bond strength over conventional elastic attachment adhesives. The addition of a crystalline polymer to conventional rubber-based elastic attachment adhesive also results in elastic attachment adhesive compositions having improved bond strength. These elastic attachment adhesive compositions are particularly suitable for use in absorbent articles.
1. A laminated structure comprising:
a first elastomeric substrate;
a second substrate being selected from the group consisting of a necked-bonded laminate, a stretch-bonded laminate, a polypropylene spunbonded layer, a polyethylene layer in combination with a polypropylene spunbonded layer, a styrene-ethylene/propylene-styrene strand, a styrene/ethylene-co-butadiene/styrene strand, and a polyurethane strand; and
an elastic attachment adhesive composition bonding the first substrate and the second substrate to one another, wherein the adhesive composition includes a rubber-based adhesive and a crystalline polymer having a degree of crystallinity of at least about 60%.
2. The laminated structure of claim 1 , wherein the adhesive composition comprises between about 70% (by weight) and about 90% (by weight) of the rubber-based adhesive, and between about 10% (by weight) and about 30% (by weight) of the crystalline polymer.
3. The laminated structure of claim 1 , wherein the adhesive composition comprises between about 75% (by weight) and about 90% (by weight) of the rubber-based adhesive, and between about 10% (by weight) and about 25% (by weight) of the crystalline polymer.
4. The laminated structure of claim 1 , wherein the degree of crystallinity of the crystalline polymer is at least about 80%.
5. The laminated structure of claim 1 , wherein the crystalline polymer has a number-average molecular weight between about 3,000 and about 200,000.
6. The laminated structure of claim 1 , wherein the crystalline polymer has a number-average molecular weight between about 10,000 and about 100,000.
7. The laminated structure of claim 1 , wherein the rubber-based adhesive comprises at least one of the group consisting of styrene-isoprene-styrene, styrene-butadiene-styrene, styrene-ethylene/propylene-styrene, ethylene-propylene-diene-monomer, styrene/ethylene-co-butadiene/styrene, and styrene-poly(ethylene-propylene)-styrene-poly(ethylene-propylene).
8. The laminated structure of claim 1 , wherein the crystalline polymer comprises at least one of the group consisting of isotactic polymer, syndiotactic polymer, and combinations thereof.
9. The laminated structure of claim 1 , wherein the crystalline polymer comprises isotactic polypropylene.
10. The laminated structure of claim 1 , wherein the crystalline polymer is selected from the group consisting of: high density polyethylene, isotactic polystyrene, isotactic polybutene, and combinations thereof.
11. The laminated structure of claim 1 , wherein the first and second substrates are each part of a single substrate.
12. 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.
13. 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.
14. The laminated structure of claim 1 , wherein the first elastomeric substrate can be stretched between about 25% and about 300%.
15. The laminated structure of claim 1 , wherein the first elastomeric substrate can be stretched between about 70% and about 270%.
16. The laminated structure of claim 1 , wherein the first elastomeric substrate can be stretched between about 100% and about 250%.
17. The laminated structure of claim 1 , wherein the elastic attachment adhesive composition is stretchable.
18. The laminated structure of claim 1 , wherein the second substrate is non-elastic.
19. The laminated structure of claim 1 , wherein the second substrate is elastomeric.
20. The laminated structure of claim 1 , wherein the first elastomeric substrate is machine-direction stretchable.
21. The laminated structure of claim 1 , wherein the first elastomeric substrate is cross-direction stretchable.
22. The laminated structure of claim 1 , wherein the second substrate is machine-direction stretchable.
23. The laminated structure of claim 1 , wherein the second substrate is cross-direction stretchable.
24. The laminated structure of claim 1 , wherein the first elastomeric substrate comprises at least one of the group consisting of a necked-bonded laminate, a stretch-bonded laminate, a polypropylene spunbonded layer, a polyethylene layer in combination with a polypropylene spunbonded layer, a styrene-isoprene-styrene strand, a styrene-butadiene-styrene strand, a styrene-ethylene/propylene-styrene strand, a styrene/ethylene-co-butadiene/styrene strand, and a polyurethane strand.
25. An absorbent article comprising:
a first elastomeric substrate;
a second substrate being selected from the group consisting of a necked-bonded laminate, a stretch-bonded laminate, a polypropylene spunbonded layer, a polyethylene layer in combination with a polypropylene spunbonded layer, a styrene-ethylene/propylene-styrene strand, a styrene/ethylene-co-butadiene/styrene strand, and a polyurethane strand; and
an elastic attachment adhesive composition bonding the first substrate and the second substrate to one another, wherein the adhesive composition includes between about 70% (by weight) and about 90% (by weight) of a rubber-based adhesive and between about 10% (by weight) and about 30% (by weight) of a crystalline polymer having a degree of crystallinity of at least about 40%.
26. The absorbent article of claim 25 , wherein the degree of crystallinity of the crystalline polymer is at least about 60%.
27. The absorbent article of claim 25 , wherein the degree of crystallinity of the crystalline polymer is at least about 80%.
28. The absorbent article of claim 25 , wherein the crystalline polymer has a number-average molecular weight between about 3,000 and about 200,000.
29. The absorbent article of claim 25 , wherein the crystalline polymer has a number-average molecular weight between about 10,000 and about 100,000.
30. The absorbent article of claim 25 , wherein the rubber-based adhesive comprises at least one of the group consisting of styrene-isoprene-styrene, styrene-butadiene-styrene, styrene-ethylene/propylene-styrene, ethylene-propylene-diene-monomer, styrene/ethylene-co-butadiene/styrene, and styrene-poly(ethylene-propylene)-styrene-poly(ethylene-propylene).
31. The absorbent article of claim 25 , wherein the crystalline polymer comprises at least one of the group consisting of isotactic polymer, syndiotactic polymer, and combinations thereof.
32. The absorbent article of claim 25 , wherein the crystalline polymer comprises isotactic polypropylene.
33. The absorbent article of claim 25 , wherein the crystalline polymer is selected from the group consisting of: high density polyethylene, isotactic polystyrene, isotactic polybutene, and combinations thereof.
34. The absorbent article of claim 25 , wherein the first and second substrates are each part of a single substrate folded over.
35. The absorbent article of claim 25 , wherein the first elastomeric substrate can be stretched between about 25% and about 300%.
36. The absorbent article of claim 25 , wherein the first elastomeric substrate can be stretched between about 70% and about 270%.
37. The absorbent article of claim 25 , wherein the first elastomeric substrate can be stretched between about 100% and about 250%.
38. The absorbent article of claim 25 , wherein the elastic attachment adhesive composition is stretchable.
39. The absorbent article of claim 25 , wherein the second substrate is non-elastic.
40. The absorbent article of claim 25 , wherein the second substrate is elastomeric.
41. The absorbent article of claim 25 , wherein the first elastomeric substrate comprises at least one of the group consisting of a necked-bonded laminate, a stretch-bonded laminate, a polypropylene spunbonded layer, a polyethylene layer in combination with a polypropylene spunbonded layer, a styrene-isoprene-styrene strand, a styrene-butadiene-styrene strand, a styrene-ethylene/propylene-styrene strand, a styrene/ethylene-co-butadiene/styrene strand, and a polyurethane strand.
42. The absorbent article of claim 25 , comprising a diaper.
43. The absorbent article of claim 25 , comprising swim wear.
44. The absorbent article of claim 25 , comprising child training pants.
45. The absorbent article of claim 25 , comprising an adult incontinence garment.
46. The absorbent article of claim 25 , comprising a feminine care product.
47. The absorbent article of claim 25 , comprising a medical garment.
48. A laminated structure comprising:
a first elastomeric substrate;
a second substrate being selected from the group consisting of a necked-bonded laminate, a stretch-bonded laminate, a polypropylene spunbonded layer, a polyethylene layer in combination with a polypropylene spunbonded layer, a styrene-ethylene/propylene-styrene strand, a styrene/ethylene-co-butadiene/styrene strand, and a polyurethane strand; and
an elastic attachment adhesive composition bonding the first substrate and the second substrate to one another, wherein the adhesive composition comprises between about 75% (by weight) and about 90% (by weight) rubber based adhesive and between about 10% (by weight) and about 30% (by weight) crystalline polymer having a degree of crystallinity of at least about 40%, and wherein the rubber-based adhesive is selected from the group consisting of styrene-isoprene-styrene, styrene-butadiene-styrene, styrene-ethylene/propylene-styrene, styrene/ethylene-co-butadiene/styrene, and styrene-poly(ethylene-propylene)-styrene-poly(ethylene-propylene).