Latent reactive adhesive film

Patent metadata

Field	Value
Publication number	US-11535778-B2
Application number	US-201917051074-A
Country	US
Kind code	B2
Filing date	Apr 26, 2019
Priority date	Apr 27, 2018
Publication date	Dec 27, 2022
Grant date	Dec 27, 2022

Abstract

The invention relates to an adhesive film which comprises a layer of an adhesive that comprises one or more polymers and at least one peroxide, characterized in that the adhesive comprises at last 50% by weight of thermoplastic polymers that do not have C═C multiple bonds, in that at least one peroxide has the general structural formula R—O—O—R′, wherein R and R′ each represent organyl groups or together represent a cyclic organyl group, and in that the peroxide in solution has a 1-minute half-life temperature of less than 200° C. In a preferred embodiment, the thermoplastic polymer is a polyurethane and the peroxide is a dicumyl peroxide.

First claim

The invention claimed is:

1. A latently reactive adhesive composition consisting of:
one or more polymers and at least one peroxide,
wherein, the one or more polymers comprises at least 50% by weight of a polyurethane lacking C═C multiple bonds,
wherein the at least one peroxide has the general structural formula R—O—O—R′ where R and R′ each represent organyl groups or collectively represent a cyclic organyl group, and
wherein the polyurethane of the adhesive composition melts and crosslinks upon thermal activation.

2. The latently reactive adhesive composition of claim 1 , wherein the at least one peroxide is dicumyl peroxide.

3. A latently reactive adhesive composition consisting of:
one or more polymers, at least one peroxide, and at least one adhesion promoter,
wherein, the one or more polymers comprises at least 50% by weight of a polyurethane lacking C═C multiple bonds,
wherein the at least one peroxide has the general structural formula R—O—O—R′ where R and R′ each represent organyl groups or collectively represent a cyclic organyl group, and
wherein the polyurethane of the adhesive composition melts and crosslinks upon thermal activation.

4. The latently reactive adhesive composition according to claim 1 , wherein an amount of the at least one peroxide in the adhesive is within a range of from 0.1% to 10% by weight.

5. The latently reactive adhesive composition according to claim 1 , wherein the at least one peroxide is a ketone peroxide or a cyclic peroxide.

6. The latently reactive adhesive composition according to claim 1 , wherein the polyurethane is semicrystalline.

7. The latently reactive adhesive composition according to claim 1 , wherein the polyurethane has a maximum softening temperature of not more than 25° C.

8. The latently reactive adhesive composition according to claim 1 , wherein the polyurethane has a maximum glass transition temperature of not more than −25° C., as determined by dynamic differential calorimetry (DSC).

9. The latently reactive adhesive composition according to claim 1 , wherein an adhesive strength of the latently reactive adhesive composition, as disposed on a substrate surface, after curing, and after storage at 23° C., 50% relative humidity (RH) for eighteen weeks, is at least 90% of an adhesive strength of the latently reactive adhesive composition, as disposed on a substrate surface, after curing, and after storage for not more than one day at 23° C., 50% RH.

10. The latently reactive adhesive composition according to claim 1 , wherein an adhesive strength of the latently reactive adhesive composition, as disposed on a substrate surface, after curing, and after storage at 40° C. for eighteen weeks in a drying cabinet under standard climatic conditions (23° C./50% relative humidity (RH)), is at least 90% of an adhesive strength of the latently reactive adhesive composition, as disposed on a substrate surface, after curing, and after storage for not more than one day at 23° C., 50% RH.

11. The latently reactive adhesive composition according to claim 3 , wherein the at least one peroxide is dicumyl peroxide.

12. The latently reactive adhesive composition according to claim 3 , wherein an amount of the at least one peroxide in the adhesive is within a range of from 0.1% to 10% by weight.

13. The latently reactive adhesive composition according to claim 3 , wherein the at least one peroxide is a ketone peroxide or a cyclic peroxide.

14. The latently reactive adhesive composition according to claim 3 , wherein the at least one adhesion promoter is at least one silane functionalized by one or more alkoxy groups.

15. The latently reactive adhesive composition according to claim 14 , wherein the one or more alkoxy groups comprises methoxy and/or ethoxy groups.

16. The latently reactive adhesive composition according to claim 3 , wherein the polyurethane is semicrystalline.

17. The latently reactive adhesive composition according to claim 3 , wherein the polyurethane has a maximum softening temperature of not more than 25° C.

18. The latently reactive adhesive composition according to claim 3 , wherein the polyurethane has a maximum glass transition temperature of not more than −25° C., as determined by dynamic differential calorimetry (DSC).

19. The latently reactive adhesive composition according to claim 3 , wherein an adhesive strength of the latently reactive adhesive composition, as disposed on a substrate surface, after curing, and after storage at 23° C., 50% relative humidity (RH) for eighteen weeks, is at least 90% of an adhesive strength of the latently reactive adhesive composition, as disposed on a substrate surface, after curing, and after storage for not more than one day at 23° C., 50% RH.

20. The latently reactive adhesive composition according to claim 3 , wherein an adhesive strength of the latently reactive adhesive composition, as disposed on a substrate surface, after curing, and after storage at 40° C. for eighteen weeks in a drying cabinet under standard climatic conditions (23° C./50% relative humidity (RH)), is at least 90% of an adhesive strength of the latently reactive adhesive composition, as disposed on a substrate surface, after curing, and after storage for not more than one day at 23° C., 50% RH.

Assignees

• Tesa Se

Inventors

• Kupsky Marco
• Dollase Thilo
• Koop Matthias
• Preuss Philipp

Classifications

• C08G2170/20

  Compositions for hot melt adhesives · CPC title

• C08G18/86

  by peroxides · CPC title

• C09J175/04 Primary

  Polyurethanes · CPC title

• C09J7/10 Primary

  without carriers · CPC title

• C09J2301/312

  parameters being the characterizing feature · CPC title