Adhesive for rubber bonding

Patent metadata

Field	Value
Publication number	US-10005935-B2
Application number	US-201615142713-A
Country	US
Kind code	B2
Filing date	Apr 29, 2016
Priority date	May 1, 2015
Publication date	Jun 26, 2018
Grant date	Jun 26, 2018

Abstract

Films comprising a resin matrix, an entanglement polymer, and a latent curative, wherein the resin has a functionality of at least 2.0 and a viscosity of at least 0.1 Pascal-seconds, and the film is dimensionally stable at 25° C. The films are particularly useful for the bonding of elastomers to rigid substrates, such as rubber to metal, and contain no volatile organic compounds (VOCs), and are shelf stable for extended periods of time.

First claim

What is claimed is:

1. A film composition comprising a resin matrix, an entanglement polymer, and a latent curative, wherein the resin has a functionality of at least 2.0 and a viscosity of at least 0.1 Pascal-seconds, and the film is dimensionally stable at 25° C.

2. The film of claim 1 , wherein the resin matrix comprises a mixture of a first resin and a second resin having different molecular weights.

3. The film of claim 2 , wherein the first resin comprises a molecular weight of less than about 500 Daltons.

4. The film of claim 2 , wherein the second resin comprises a molecular weight of about 400 to about 4000 Daltons.

5. The film of claim 2 , wherein the first resin comprises between 40 and 60 weight percent, and the second resin comprises between 60 and 40 weight percent based on the total weight of the resin matrix.

6. The film of claim 1 , wherein the resin matrix comprises at least one of a phenolic resin, an acrylic resin, or an epoxy resin and is liquid at 25° C.

7. The film of claim 1 , wherein the resin matrix comprises an epoxy-functional resin.

8. The film of claim 1 , wherein the resin matrix comprises an epoxy novolac, a tris-(hydroxyl phenyl) methane-based epoxy resin.

9. The film of claim 1 , wherein the entanglement polymer comprises a high molecular weight polymer with a number average molecular weight of at least 15,000 Daltons.

10. The film of claim 9 , wherein the molecular weight of the entanglement polymer is at least 100,000 Daltons.

11. The film of claim 1 , wherein the entanglement polymer contains moieties capable of reacting with at least one of the resin matrix, or the latent curative.

12. The film of claim 1 , wherein the entanglement polymer comprises at least one of carboxylated nitrile rubber, natural rubber, chlorinated natural rubber, epoxy terminated phenoxy polymer, an epoxy-rubber adduct, an unsaturated polymer such as chlorosulfonated polyethylene, hydrogenated nitrile butadiene rubber (HNBR), polyacrylate elastomers, or epichlorohydrin elastomers, or combinations thereof.

13. The film of claim 1 , wherein the entanglement polymer comprises at least one of a block copolymer or a random copolymer.

14. The film of claim 1 , wherein the latent curative comprises at least one of dicyandiamide, urea, or dinitrosobenzene (DNB).

15. The film of claim 14 , wherein the dicyandiamide is present at about 2 to about 8 phr, the urea is present in an amount from 0 to about 5 phr, and the dinitrosobenzene is present in an amount from 0 to about 15 phr, based on the total weight of the rein and entanglement polymer.

16. The film of claim 1 , wherein the latent curative comprises a catalyst and optionally an accelerator.

17. The film of claim 1 , further comprising an elastomer crosslinker.

18. The film of claim 17 , wherein the elastomer crosslinker comprises dinitrosobenzene.

19. The film of claim 1 , wherein the resin is present from about 50 to about 70 weight percent, the entanglement polymer is present from about 15 to about 25 weight percent, and the latent curative is present from about 5 to about 15 weight percent, based on the total weight of those three constituents in the film.

20. The film of claim 1 , further comprising a conductive filler comprising at least one of a thermally conductive filler or an electrically conductive filler.

21. The film of claim 1 , wherein the film contains no water or solvent.

22. The film of claim 1 , further comprising a metal adhesion promoter.

23. The film of claim 22 , wherein the metal adhesion promoter comprises at least one of a phenolic resin, a silane, or an organotitanate.

24. The film of claim 1 , disposed between an elastomer substrate and a metal substrate to form an assembly.

25. The film of claim 24 , wherein no other primer or adhesive materials are disposed between the elastomer substrate and the metal substrate.

26. The film of claim 1 , wherein the film in the assembly comprises a tack peel strength of at least 2 pli as measured according to ASTM D429.

27. The film of claim 24 , wherein the elastomer substrate comprises at least one of natural rubber, nitrile, neoprene, chlorobutyl rubber, bromobutyl rubber, or styrene-butadiene rubber.

28. The film of claim 27 , wherein the assembly is heated to at least 80° C. to cure the film.

29. The film of claim 28 , wherein the cured film in the assembly exhibits a peel strength of at least 25 pli, as measured by ASTM D429.

30. The film of claim 1 , incorporated into a multi-layer laminate comprising a primer side for contact with a metallic substrate and an adhesive side for contact with an elastomer.

31. The film of claim 1 , incorporated into a multi-layer laminate comprising an additional layer comprising an elastomer film.

32. The film of claim 31 , wherein the elastomer film is selected to correspond to an elastomer substrate.

Assignees

• Lord Corp

Inventors

• Fornes Timothy
• Cox Christopher

Classifications

• B32B25/04

  comprising rubber as the main or only constituent of a layer, {which is} next to another layer of {the same or of} a {different material (next to a layer of a particular substance B32B9/043; next to a bituminous or tarry layer B32B11/044; next to a water setting substance layer B32B13/042; next to a metal layer B32B15/06; next to a glass layer B32B17/063; next to a layer formed of natural mineral fibres or particles B32B19/043; next to a wood layer B32B21/045; next to a cellulosic plastic layer B32B23/046)} · CPC title

• C09J7/10 Primary

  without carriers · CPC title

• C09J133/10

  Homopolymers or copolymers of methacrylic acid esters · CPC title

• B32B2307/748

  Releasability · CPC title

• B32B25/00

  Layered products comprising {a layer of} natural or synthetic rubber {(fibrous or filamentary layer made of a natural or synthetic rubber B32B5/02; particulate layer made of a natural or synthetic rubber B32B5/16; foamed layer made of a natural or synthetic rubber B32B5/18)} · CPC title