Polyurea-based adhesives, articles therefrom and methods of their preparation and use

• US 6,824,820 B1
• Filed: 07/30/1999
• Issued: 11/30/2004
• Est. Priority Date: 06/07/1999
• Status: Expired due to Term

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Leir, Charles M., Dastur, Meherdil D., Sherman, Audrey A., Kinning, David J.
• Primary Examiner(s): Yoon, Tae H.
• Application Number:
  US09/355,601
• Time in Patent Office: 1,950 Days
• Field of Search: 524/270, 524/505, 524/589, 528/28, 528/61, 427/208.4, 427/208.6, 427/208.8, 428/343, 428/349
• US Class Current: 427/208.4
• CPC Class Codes: C08G 18/5024 containing primary and/or secondary amino groups
• CPC Class Codes: C08G 18/61 Polysiloxanes
• CPC Class Codes: C08G 18/765 alpha, alpha, alpha', alpha', -tetraalkylxylylene diisocyanate or homologues substituted on the aromatic ring
• CPC Class Codes: C08G 2170/40 Compositions for pressure-sensitive adhesives
• CPC Class Codes: C09J 2475/00 Presence of polyurethane
• CPC Class Codes: C09J 2475/006 in the substrate
• CPC Class Codes: C09J 7/22 Plastics; Metallised plastics
• CPC Class Codes: C09J 7/35 Heat-activated
• CPC Class Codes: C09J 7/38 Pressure-sensitive adhesives [PSA]
• 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 428/2826 Synthetic resin or polymer

Abstract

An adhesive composition comprising

a silicone free polyurea-based polymer, comprising a segmented copolymer, wherein the copolymer comprises repeating units of Formula I:

wherein:

each B is independently a polyvalent radical selected form a group consisting of arylene, aralkylene, cycloalkylene, polyoxyalkylene, or mixtures thereof;

each D is independently selected from the group consisting of hydrogen, an alkyl group, a cycloalkyl group, a phenyl group, a group that completes a ring structure that includes B to form a heterocycle, and mixtures thereof;

each Z is independently a polyvalent radical having about 1 to about 20 carbon atoms;

each Y is independently a polyoxyalkylene;

m is an integer greater than zero; and

a is zero or an integer greater than zero; and

wherein the composition comprises a tackifier in an amount sufficient to provide the adhesive composition as a pressure sensitive adhesive and in an amount less than about 45 parts by weight tackifier per hundred part by weight polyurea-based polymer.

Claims

1. An adhesive composition comprising

a silicone free polyurea-based polymer, comprising a segmented copolymer, wherein the copolymer comprises repeating units of Formula I:

wherein;

each B is independently a polyvalent radical selected from a group consisting of arylene, aralkylene, cycloalkylene, polyoxyalkylene, or mixtures thereof;

each D is independently selected from the group consisting of hydrogen, an alkyl group, a cycloalkyl group, a phenyl group, a group that completes a ring structure that includes B to form a heterocycle, and mixtures thereof;

each Z is independently a polyvalent radical having about 1 to about 20 carbon atoms;

each Y is independently a polyoxyalkylene;

m is an integer greater than zero; and

a is zero or an integer greater than zero; and

wherein the composition comprises a tackifier in an amount sufficient to provide the adhesive composition as a pressure sensitive adhesive and in an amount less than about 45 parts by weight tackifier per hundred part by weight polyurea-based polymer.

2. The composition of claim 1, wherein B is a polyoxyalkylene.

3. The composition of claim 1, wherein Y is selected from the group consisting of polyethylene oxide, polypropylene oxide, and polytetramethylene oxide.

4. The composition of claim 1, wherein a is an integer greater than zero.

5. The composition of claim 1, wherein the composition exhibits a peel adhesion of greater than about 20.0 N/dm when tested according to ASTM D 3330-90, wherein ASTM D 3330-90 is modified by substituting a glass substrate for a stainless steel substrate.

6. The composition of claim 1, wherein the composition exhibits a shear strength of greater than about one minute when tested according to ASTM D 3654-88.

7. The composition of claim 1, wherein the composition exhibits a shear strength of greater than about 10 minutes when tested according to ASTM D 3654-88.

8. The composition of claim 1, wherein the composition exhibits a shear strength of greater than about 100 minutes when tested according to ASTM D 3654-88.

9. The composition of claim 1, wherein the polyurea-based polymer comprises a segmented copolymer, wherein at least about 0.5 mole fraction of linkages between segments in a backbone of the polymer are urea linkages.

10. The composition of claim 1, wherein the polyurea-based polymer comprises a segmented copolymer, wherein at least about 0.75 mole fraction of linkage between segments in a backbone of the polymer are urea linkages.

11. The composition of claim 1, wherein the polyurea-based polymer comprises a segmented copolymer, wherein at least about 0.95 mole fraction or linkages between segments in a backbone of the polymer are urea linkages.

12. The composition of claim 1, wherein the composition further comprises an acid-containing polymeric material.

13. An adhesive tape comprising:

a backing; and

the adhesive composition of claim 1 coated on at least a portion thereof.

14. The adhesive tape of claim 13, wherein the backing comprises a polyurea.

15. The adhesive tape of claim 13, further comprising a release material coated on at least a portion of the backing, on a side of the backing opposite of the adhesive.

16. A method of preparing the adhesive composition of claim 1, the method comprising the steps of:

providing at least one polyisocyanate;

providing at least one polyamine;

reacting the at least one polyisocyanate with the at least polyamine to form the polyurea-based polymer; and

optionally adding the tackifier to the polyurea-based polymer.

17. The method of claim 16, wherein at least one polyisocyanate and the at least one polyamine are reacted by reactive extrusion.

18. The method of claim 16, further comprising the stop of hot-melt coating the adhesive composition onto a substrate.

19. The method of claim 16, further comprising the step of solvent coating the adhesive composition onto a substrate.

20. The method of claim 16, wherein the polyurea-based polymer is polymerized on-web.

21. The adhesive composition of claim 1, wherein the polyurea-based polymer exhibits a peel adhesion of greater than about 10.0 N/dm when tested according to ASTM D 3330-90, wherein ASTM D 3330-90 is modified by substituting a glass substrate for a stainless steel substrate.