Pressure-sensitive adhesive blends comprising ethylene/propylene-derived polymers and propylene-derived polymers and articles therefrom

• US 6,489,400 B2
• Filed: 12/21/2000
• Issued: 12/03/2002
• Est. Priority Date: 12/21/2000
• Status: Expired due to Term

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Siedle, Allen R., Khandpur, Ashish K., Bennett, Greggory S.
• Primary Examiner(s): Nutter, Nathan M.
• Application Number:
  US09/746,612
• Publication Number:
  US 20020120064A1
• Time in Patent Office: 712 Days
• Field of Search: 525/191, 525/240, 428/500, 428/343, 428/355.EN
• US Class Current: 525/191
• CPC Class Codes: C08L 2205/02 containing two or more polymers of the same C08L -group
• CPC Class Codes: C08L 23/10 Homopolymers or copolymers of propene
• CPC Class Codes: C08L 23/14 Copolymers of propene C08L23/16 takes precedence
• 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 123/14 Copolymers of propene C09J123/16 takes precedence
• 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 428/2878 including addition polymer from unsaturated monomer
• CPC Class Codes: Y10T 428/31855 Of addition polymer from unsaturated monomers

Abstract

The present invention relates to a blend of at least one amorphous ethylene/propylene-derived copolymer, at least one non-stereoregular propylene-derived polymer having a melt viscosity of greater than about 500 Poise, and an optional tackifier that provide pressure-sensitive adhesive compositions in which a good balance of adequate adhesion to both low and relatively high surface energy substrates can be achieved.

Claims

1. A pressure-sensitive adhesive composition comprising a blend of:

at least one amorphous ethylene/propylene-derived copolymer,

at least one non-stereoregular propylene-derived polymer having a melt viscosity of greater than about 500 Poise, and

optionally at least one tackifier.

2. The pressure-sensitive adhesive composition of claim 1, wherein the at least one propylene-derived polymer has a stereoregularity index of about 1.0 to about 5.0.

3. The pressure-sensitive adhesive composition of claim 1, wherein the at least one propylene-derived polymer comprises polypropylene.

4. The pressure-sensitive adhesive composition of claim 3, wherein the polypropylene is a metallocene-generated polypropylene.

5. The pressure-sensitive adhesive composition of claim 1, wherein the at least one ethylene/propylene-derived copolymer has a glass transition temperature (Tg) of greater than −

40°

C. to about 0°

C.

6. The pressure-sensitive adhesive composition of claim 1, wherein the at least one ethylene/propylene-derived copolymer is derived from less than 30% by weight ethylene monomers.

7. The pressure-sensitive adhesive composition of claim 1, wherein the at least one ethylene/propylene-derived copolymer is derived from essentially no diene monomers.

8. The pressure-sensitive adhesive composition of claim 1, wherein the at least one ethylene/propylene-derived copolymer is derived from a major portion of propylene monomers.

9. The pressure-sensitive adhesive composition of claim 1, wherein the composition is crosslinked.

10. The pressure-sensitive adhesive composition of claim 1, wherein the at least one propylene-derived polymer has a weight average molecular weight of about 70,000 grams/mole to about 1,000,000 grams/mole.

11. The pressure-sensitive adhesive composition of claim 1, wherein the at least one propylene-derived polymer has a melt viscosity of greater than about 750 Poise.

12. The pressure-sensitive adhesive composition of claim 1, wherein the at least one propylene-derived polymer has a Tg of about −

15°

C. to about 10°

C.

13. The pressure-sensitive adhesive composition of claim 1, wherein the at least one propylene-derived polymer is derived from essentially no diene monomers.

14. The pressure-sensitive adhesive composition of claim 1, wherein the at least one propylene-derived polymer is derived from at least about 60% by weight propylene monomers.

15. The pressure-sensitive adhesive composition of claim 1, wherein the at least one propylene-derived polymer has a weight average molecular weight of at least about 10,000 grams/mole.

16. The pressure-sensitive adhesive composition of claim 1, wherein the composition comprises a single domain system.

17. The pressure-sensitive adhesive composition of claim 1, wherein the composition comprises a major portion of the at least one amorphous ethylene/propylene-derived copolymer and a minor portion of the at least one propylene-derived polymer based on total weight of the ethylene/propylene-derived copolymer and propylene-derived polymer components.

18. An article comprising:

a substrate; and

a pressure-sensitive adhesive composition comprising a blend of;

at least one amorphous ethylene/propylene-derived copolymer,

at least one non-stereoregular propylene-derived polymer having a melt viscosity of greater than about 500 Poise, and

optionally at least one tackifier;

wherein the pressure sensitive adhesive is at least partially applied to the substrate.

19. The article of claim 18, wherein the substrate comprises polypropylene and the pressure-sensitive adhesive composition has a 180°

peel adhesion to the substrate of at least about 100 N/dm.

20. The article of claim 18, wherein the substrate comprises polyethylene and the pressure-sensitive adhesive composition has a 180°

peel adhesion to the substrate of at least about 100 N/dm.

21. The article of claim 18, wherein the substrate comprises glass and the pressure-sensitive adhesive composition has a 180°

peel adhesion to the substrate of at least about 100 N/dm.

22. A tape comprising:

a backing having a first and second side; and

a pressure-sensitive adhesive composition comprising a blend of;

at least one amorphous ethylene/propylene-derived copolymer,

at least one non-stereoregular propylene-derived polymer having a melt viscosity of greater than about 500 Poise, and

optionally at least one tackifier;

wherein the pressure sensitive adhesive is applied on at least a portion of the first side of the backing and, optionally, on at least a portion of the second side of the backing.

23. A process for preparing a pressure-sensitive adhesive composition comprising the steps of:

providing at least one amorphous ethylene/propylene-derived copolymer,

providing at least one non-stereoregular propylene-derived polymer having a melt viscosity of greater than about 500 Poise,

optionally, adding at least one tackifier to the composition, and

blending the composition comprising the at least one amorphous ethylene/propylene-derived copolymer and the least one non-stereoregular propylene-derived polymer to form the pressure-sensitive adhesive composition.