Hot Melt Adhesive Based on Olefin Block Copolymers

• US 20110021103A1
• Filed: 07/23/2010
• Published: 01/27/2011
• Est. Priority Date: 07/24/2009
• Status: Active Grant

• Current Assignee: Bostik Incorporated (Totalenergies Se)
• Original Assignee: Bostik Incorporated (Totalenergies Se)
• Inventors: Alper, Mark D., Kanderski, Monina D.
• Granted Patent: US 8,921,474 B2
• Time in Patent Office: Days
• US Class Current: 442/329
• CPC Class Codes: A61F 13/4902 characterised by the elastic material
• CPC Class Codes: B32B 2255/02 on fibrous or filamentary layer
• CPC Class Codes: B32B 2255/10 on synthetic resin layer or on natural or synthetic rubber layer
• CPC Class Codes: B32B 2255/26 Polymeric coating
• CPC Class Codes: B32B 2262/00 Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
• CPC Class Codes: B32B 2272/00 Resin or rubber layer comprising scrap, waste or recycling material
• CPC Class Codes: B32B 2274/00 Thermoplastic elastomer material thermoplastic elastomer fibres B32B2262/0215, thermoplastic elastomer particles B32B2264/0221, thermoplastic elastomer foam B32B2266/0292
• CPC Class Codes: B32B 2307/51 Elastic
• CPC Class Codes: B32B 2309/14 Velocity, e.g. feed speeds
• CPC Class Codes: B32B 2555/02 Diapers or napkins
• CPC Class Codes: B32B 27/12 next to a fibrous or filamentary layer
• CPC Class Codes: B32B 27/32 comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• 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 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 53/02 of vinyl-aromatic monomers and conjugated dienes
• 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: 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 1/4374 using different kinds of webs, e.g. by layering webs
• CPC Class Codes: Y10T 442/60 Nonwoven fabric [i.e., nonwoven strand or fiber material]
• CPC Class Codes: Y10T 442/602 : Nonwoven fabric comprises an elastic strand or fiber material

Abstract

A hot melt adhesive composition, comprising a blend of components including about 5% to about 50% by weight of an olefin block copolymer; about 10% to about 70% by weight of a first tackifying resin having a softening point of at least about 95° C.; about 0 to 65% of a second tackifying resin that is different than the first tackifying resin; about 0% to about 60% by weight of a plasticizer; about 0% to about 20% by weight of an aromatic reinforcing resin having a softening point equal to or higher than 115° C.; about 0.1% to about 5% by weight of a stabilizer; and about 1% to about 40% by weight of a secondary polymer that is different from the olefin block copolymer, the first and second tackifying resins and the reinforcing resin, having relatively low crystallinity, which low crystallinity is equal to or less than 250 Joules/gram, wherein the components total 100% by weight of the composition, and the viscosity of the composition is equal to or less than about 20,000 mPa·s at 163° C. Laminates, especially those used in disposable soft goods, and methods of making such laminates using the hot melt adhesive composition are also described. The adhesive composition and/or laminate may be used in making a variety of end products such as a disposable diaper, a sanitary napkin, a bed pad, a bandage, a surgical drape, a tape, a label, a plastic sheet, a nonwoven sheet, a paper sheet, a cardboard, a book, a filter, or a package.

Claims

1. A hot melt adhesive composition, comprising a blend of the following components:

about 5% to about 50% by weight of an olefin block copolymer;

about 10% to about 70% by weight of a first tackifying resin having a softening point of at least about 95°

C.;

about 0 to 65% of second tackifying resin different than the first tackifying resin;

about 0% to about 60% by weight of a plasticizer; and

about 0% to about 20% by weight of an aromatic reinforcing resin having a softening point equal to or higher than 115°

C.;

about 1% to about 40% by weight of a secondary polymer having relatively low crystallinity, which low crystallinity is equal to or less than 250 Joules/gram, said secondary polymer being a polymer that is different from the olefin block copolymer, the first and second tackifying resins, and the reinforcing resin; and

about 0.1% to about 5% by weight of a stabilizer;

wherein the components total 100% by weight of the composition, and the viscosity of the composition is equal to or less than about 20,000 mPa·

s at 163°

C.,

2. The composition of claim 1 further including about 1% to about 25% by weight of an auxiliary polymer selected from the group consisting of SB, SI, SIS, SBS, EVA, SEB, SEEPS, SIBS, SEBS, SEP, SEPS, SBBS and blends thereof, said auxiliary polymer being a polymer that is different from the olefin block copolymer, the first and second tackifying resins, the reinforcing resin, and the secondary polymer.

3. The composition of claim 1 comprising about 10% to about 30% by weight of said olefin block copolymer.

4. The composition of claim 1 comprising about 12% to about 20% by weight of said olefin block copolymer.

5. The composition of claim 1 comprising about 2% to about 30% by weight of said plasticizer.

6. The composition of claim 1 wherein said first tackifying resin has a softening point of from about 95°

C. to about 140°

C.

7. The composition of claim 1 wherein said composition has a viscosity equal to or less than 15,000 mPa·

s at 163°

C.

8. The composition of claim 1 wherein said composition has a viscosity equal to or less than 12,000 mPa·

s at 163°

C.

9. The composition of claim 1 comprising about 2% to about 15% of said aromatic reinforcing resin.

10. The composition of claim 1 wherein the aromatic reinforcing resin is a product from pure monomer polymerization.

11. The composition of claim 1 wherein the aromatic reinforcing resin has a softening point of from about 115°

C. to about 160°

C.

12. The composition of claim 1 wherein the aromatic reinforcing resin has a softening point of from about 115°

C. to about 140°

C.

13. The composition of claim 1 wherein the aromatic reinforcing resin has a softening point of from about 120°

C. to about 140°

C.

14. The composition of claim 1 having about 40% to about 65% by weight of said first tackifying resin.

15. The composition of claim 1 having about 50% to about 60% by weight of said first tackifying resin.

16. The composition of claim 1 wherein said composition has an initial bond retention of at least about 60%.

17. The composition of claim 1 wherein said composition has an initial bond retention of at least about 70%.

18. The composition of claim 1 wherein said composition has an initial bond retention of at least about 80%.

19. The composition of claim 1 wherein said secondary polymer has a crystallinity equal to or less than 150 Joules/gram.

20. The composition of claim 1 wherein said secondary polymer has a crystallinity equal to or less than 100 Joules/gram.

21. The composition of claim 1 comprising about 2% to about 30% by weight of said secondary polymer.

22. The composition of claim 1 wherein the first tackifying resin is selected from the group consisting of aliphatic hydrocarbon resins and their hydrogenated derivatives, hydrogenated cycloaliphatic hydrocarbon resins, aromatic modified aliphatic or hydrogenated cycloaliphatic hydrocarbon resins, aliphatic modified aromatic hydrocarbon resins, partially or fully hydrogenated aromatic hydrocarbon resins, polyterpene and styrenated polyterpene resins.

23. The composition of claim 1 wherein said plasticizer is selected from the group consisting of mineral oil and liquid polybutene.

24. The composition of claim 1 further including a wax selected from the group consisting of petroleum waxes, microcrystalline waxes, low molecular weight polyethylene and polypropylene, synthetic waxes and polyolefin waxes.

25. An elastic laminate comprising a first layer of nonwoven material, a second layer of nonwoven material, and one or a plurality of elastomeric substrates disposed between said first and second nonwoven layers, bonded together with the adhesive composition of claim 1.

26. The elastic laminate of claim 25 wherein the said one or a plurality of elastomeric substrates are elastic strands.

27. An elastic laminate comprising a first layer of nonwoven material, a second layer of film material, and one or a plurality of elastomeric substrates disposed between said first and second layers, bonded together with the adhesive composition of claim 1.