Expandable compositions and methods of making and using the compositions
View Patent ↗A novel expandable composition and method for using the same are disclosed. The disclosed method relates to using the composition, for example, as an automotive cavity sealant. The inventive composition normally is a combination of at least one base polymer, at least one expansion or blowing agents, at least one hydrocarbon resin, at least one curing agent or catalyst and optionally at least one additives such as a supplemental polymer, colorant, tackifier, processing oil, among others.
1. A composition comprising a maleic anhydride-modified copolymer of ethylene and vinyl acetate, at least one expansion agent, at least one hydrocarbon resin, and at least one sulfur containing curing agent, wherein said composition does not comprise a peroxide curing agent.
2. The composition of claim 1 wherein at least one expansion agent is a hydrazide.
3. The composition of claim 1 wherein at least one expansion agent is selected from the group consisting of p,p′-oxybis(benzenesulfonyl hydrazide) and diphenylazide-4,4′-disulphohydrazides.
4. The composition of claim 1 wherein at least one hydrocarbon resin is selected from the group consisting of rosin esters polyterpenes and C5 to 9 hydrocarbon and aromatically modified hydrocarbon resins.
5. The composition of claim 1 wherein at least one sulfur containing curing agent is tetramethylthiuram disulfide.
6. The composition of claim 1 additionally comprising at least one processing oil.
7. The composition of claim 1 additionally comprising at least one supplemental polymer selected from the group consisting of ethylene acrylic acid copolymers, polybutadienes, ethylene vinyl acetate polymers, and ethylene propylene diene monomer polymers.
8. The composition of claim 1 additionally comprising at least one filler.
9. The composition of claim 1 wherein the maleic anhydride-modified copolymer of ethylene and vinyl acetate comprises from about 50 to about 90 weight percent of the composition.
10. The composition of claim 1 wherein the at least one hydrocarbon resin comprises from about 1 to about 15 weight percent of the composition.
11. The composition of claim 1 wherein the at least one expansion agent comprises from about 1 to about 15 weight percent of the composition.
12. The composition of claim 1 additionally comprising at least one urea or modified urea.
13. The composition of claim 1 comprising both p,p′-oxybis(benzenesulfonyl hydrazide) and a diphenylazide-4,4′-disulphohydrazide.
14. The composition of claim 1 comprising about 55 to about 84 weight percent of the maleic anhydride-modified copolymer of ethylene and vinyl acetate, about 1 to about 15 weight percent of the at least one expansion agent, said at least one expansion agent being selected from the group consisting of p,p′-oxybis(benzenesulfonyl hydrazide) and diphenylazide-4,4′-disulphohydrazides, about 1 to about 15 weight percent of the at least one hydrocarbon resin, and up to about 5 weight percent of tetramethylthiuram disulfide.
15. The composition of claim 14 additionally comprising from about 5 to about 10 weight percent of at least one supplemental polymer selected from the group consisting of ethylene acrylic acid copolymers and polybutadienes.
16. The composition of claim 14 additionally comprising at least one urea or modified urea.
17. The composition of claim 14 additionally comprising at least one filler.
18. The composition of claim 14 wherein at least one hydrocarbon resin is selected from the group consisting of rosin esters, polyterpenes and C5 to C9 hydrocarbon and aromatically modified hydrocarbon resins.
19. The composition of claim 14 additionally comprising at least one processing oil.
20. The composition of claim 14 comprising both p,p′-oxybis(benzenesulfonyl hydrazide) and a diphenylazide-4,4′-disulphohydrazide.
21. The composition of claim 14 wherein at least one expansion agent is pretreated with a naphthenic binder.
22. The composition of claim 1 , wherein said composition has been injection molded.
23. The composition of claim 1 , wherein said composition has been injection molded to form a self-retaining sealant.