Tackified amorphous-poly-alpha-olefin-bonded structures

• US 7,517,579 B2
• Filed: 07/18/2007
• Issued: 04/14/2009
• Est. Priority Date: 11/04/2003
• Status: Expired due to Term

• Current Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Original Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Inventors: Killian, Thomas Michael, Fairbanks, Jason Sybren, Neculescu, Cristian M., Jung, Mark J., Hesse, Daniel William, Thoresen, Rhiannon L., Hansen, Richard M., Palmer, Randall J., Schultz, Richard D., Rice, Jonathan K., Grube, Violet May, Shea, Courtney Eileen, Campbell, Stephen Michael, Rogers, Sandra Marie, Potnis, Prasad Shrikrishna, Wallajapet, Palani Raj Ramaswami
• Primary Examiner(s): Salvatore; Lynda
• Application Number:
  US11/879,642
• Publication Number:
  US 20070264515A1
• Time in Patent Office: 636 Days
• Field of Search: 442/328, 442/373, 442/381, 442/374, 428/103, 428/107, 428/109, 428/137, 428/214, 428/219, 428/102, 428/223, 428/99
• US Class Current: 428/219
• CPC Class Codes: B32B 2307/54 Yield strength; Tensile strength
• CPC Class Codes: B32B 2307/7265 Non-permeable
• 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 7/12 using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: C08L 23/10 Homopolymers or copolymers of propene
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 57/02 Copolymers of mineral oil hydrocarbons
• CPC Class Codes: C09J 123/10 Homopolymers or copolymers of propene
• CPC Class Codes: C09J 123/14 Copolymers of propene C09J123/16 takes precedence
• CPC Class Codes: Y10T 428/12278 Same structure at both ends of plural taper
• CPC Class Codes: Y10T 428/12347 Plural layers discontinuously bonded [e.g., spot-weld, mechanical fastener, etc.]
• CPC Class Codes: Y10T 428/14 Layer or component removable to expose adhesive
• CPC Class Codes: Y10T 428/24033 including stitching and discrete fastener[s], coating or bond
• CPC Class Codes: Y10T 428/249923 Including interlaminar mechanical fastener
• CPC Class Codes: Y10T 428/249982 With component specified as adhesive or bonding agent
• CPC Class Codes: Y10T 428/249985 Composition of adhesive or bonding component specified
• CPC Class Codes: Y10T 428/27 Web or sheet containing structurally defined element or component, the element or component having a specified weight per unit area [e.g., gms/sq cm, lbs/sq ft, etc.]
• CPC Class Codes: Y10T 428/28 Web or sheet containing structurally defined element or component and having an adhesive outermost layer
• CPC Class Codes: Y10T 428/2848 : Three or more layers
• CPC Class Codes: Y10T 428/2852 : Adhesive compositions
• CPC Class Codes: Y10T 428/2878 : including addition polymer from unsaturated monomer
• CPC Class Codes: Y10T 428/31913 : Monoolefin polymer
• CPC Class Codes: Y10T 442/659 : Including an additional nonwoven fabric

Abstract

A bonded structure including one or more substrates bonded together with a tackified amorphous poly-alpha-olefin adhesive composition. One method of making such a bonded structure is carried out by applying a tackified amorphous poly-alpha-olefin adhesive composition to one or more substrates at a temperature of about 170 degrees Celsius or lower, and joining the substrates to themselves or to one another. The bonded structure has a dynamic peel strength between about 400 and about 1000 grams per 25 millimeters. The bonding efficiency of the bonded structure renders the bonded structure suitable for incorporation into a variety of articles, including personal care products, health/medical products, and household/industrial product, for example.

Claims

1. A bonded structure comprising:

a first substrate;

a second substrate; and

an adhesive composition bonding the first substrate and the second substrate to one another at an add-on level between about 10 and about 15 grams/meter², wherein the adhesive composition comprises an amorphous poly-alpha-olefin and a tackifier selected from at least one of the group consisting of;

petroleum distillates, rosin, rosin esters, and polyterpenes, and the bonded structure has a dynamic peel strength between about 150 and about 1000 grams per 25 millimeters.

2. The bonded structure of claim 1, having a compression-tensile peel strength between about 80 and about 400 grams per square millimeter.

3. The bonded structure of claim 1, wherein the amorphous poly-alpha-olefin comprises propylene copolymerized with at least one of the group consisting of:

butene, ethylene, and hexene.

4. The bonded structure of claim 1, wherein the amorphous poly-alpha-olefin comprises a polypropylene-1-butene amorphous poly-alpha-olefin.

5. The bonded structure of claim 1, wherein the adhesive composition comprises between about 50% and about 99% by weight amorphous poly-alpha-olefin and between about 1% and about 50% by weight tackifier.

6. The bonded structure of claim 1, wherein the tackifier comprises a C5 hydrocarbon tackifier.

7. The bonded structure of claim 1, wherein the adhesive composition consists essentially of the amorphous poly-alpha-olefin, the tackifier, and an antioxidant stabilizer.

8. The bonded structure of claim 7, wherein the antioxidant comprises about 1% or less by weight of the adhesive composition.

9. The bonded structure of claim 1, wherein at least one of the first and second substrates has a thickness of about 40 μ

m or less.

10. The bonded structure of claim 9, wherein at least one of the first and second substrates has a thickness of about 5 μ

m to about 20 μ

m.

11. The bonded structure of claim 1, having no burn-through visual defects greater than about 1 millimeter.

12. The bonded structure of claim 1, wherein at least one of the first and second substrates comprises a low-surface-energy olefin substrate.

13. The bonded structure of claim 12, wherein the low-surface-energy olefin substrate has a surface tension of less than about 33 dynes/cm.

14. The bonded structure of claim 1, wherein at least one of the first and second substrates comprises a low-tension elastic material.

15. The bonded structure of claim 14, wherein the low-tension elastic material provides about 200 grams per inch or less of force when elongated 20%.

16. The bonded structure of claim 1, wherein at least one of the first and second substrates comprises a liquid-impermeable, water-vapor-transmissible substrate.

19. The bonded structure of claim 1, wherein the tackifier is rosin esters.

17. An article comprising:

a first substrate;

a second substrate;

an adhesive composition bonding the first substrate and the second substrate to one another at an add-on level between about 0.5 and about 25 grams/meter² thereby forming a bonded structure, wherein the adhesive composition comprises an amorphous poly-alpha-olefin and a tackifier, and the bonded structure has an end seal strength between about 60 and about 600 grams per 25 millimeters, and the article is selected from the group consisting of personal care products, health/medical products, and household/industrial products; and

the adhesive composition bonding the first substrate and the second substrate is applied by at least one of the group consisting of melt spraying, slot coating, and swirl patterning.

18. An article comprising:

a film;

a nonwoven web; and

an adhesive composition bonding the film and the nonwoven web to one another at an add-on level between about 2 and about 5 grams/meter² thereby forming a bonded structure, wherein the adhesive composition comprises a polypropylene-1-butene amorphous poly-alpha-olefin and a C5 hydrocarbon tackifier, and the bonded structure has an end seal strength between about 60 and about 600 grams per 25 millimeters, and the article is selected from the group consisting of personal care products, health/medical products, and household/industrial products, wherein the adhesive composition has a Brookfield viscosity between more than 10000 and about 15000 centipoises at 190 degrees Celsius.

20. The article of claim 18, wherein:

the adhesive composition is applied at an add-on level of about 2 grams/meter²; and

the bonded structure has a dynamic peel strength between at least about 195 grams per 25 millimeters.