Elastomeric compositions and their use in articles
A dynamically vulcanized alloy contains at least one isobutylene-containing elastomer and at least one thermoplastic resin, wherein the elastomer is present as a dispersed phase of small vulcanized or partially vulcanized particles in a continuous phase of the thermoplastic resin. The dynamically vulcanized alloy also contains an anhydride functionalized oligomer. The alloy maintains a high Shore A hardness value while obtaining improved flowability for processing.
1. A dynamically vulcanized alloy comprising the four following components:
a) at least one isobutylene-containing elastomer;
b) at least one polar thermoplastic resin,
c) an anhydride functionalized oligomer, wherein the oligomer, prior to functionalization, has a molecular weight in the range of 750 to 1250, and
d) a plasticizer, the plasticizer comprising a component selected from the group consisting of tertiary amines, secondary diamines, and sulfonamides,
wherein the anhydride functionalized oligomer and the plasticizer are present in the alloy in a ratio ranging from 0.3 to 1.5, and
wherein the anhydride functionality of the oligomer is grafted to the polar thermoplastic resin and the elastomer is present as a dispersed phase of small vulcanized or partially vulcanized particles in a continuous phase of the thermoplastic resin.
2. The alloy of claim 1 , wherein the oligomer is selected from the group consisting of an alkyl, an aryl, and an alkenyl oligomer.
3. The alloy of claim 1 , wherein the anhydride functionality is either a succinic anhydride or a maleic anhydride.
4. The alloy of claim 1 , wherein the anhydride functionalized oligomer is a poly-n-alkyl succinic anhydride or a poly-iso-alkyl succinic anhydride.
5. The alloy of claim 1 , wherein the functionalized oligomer is selected from the group consisting of poly-isobutylene succinic anhydride, polyisobutene succinic anhydride, polybutene succinic anhydride, polyisopentene succinic anhydride, polypentene succinic anhydride, polyoctenyl succinic anhydride, polyisooctenyl succinic anhydride, poly-hexenyl succinic anhydride, and poly-dodecenyl succinic anhydride.
6. The alloy of claim 1 , wherein the alloy comprises 2 to 35 phr of the anhydride functionalized oligomer, based on the amount of the isobutylene-containing elastomer in the alloy.
7. The alloy of claim 1 , wherein the alloy is substantially free of any acrylates.
8. The alloy of claim 1 , wherein said elastomer is a halogenated butyl rubber.
9. The alloy of claim 1 , wherein said elastomer is a copolymer of isobutylene and an alkylstyrene.
10. The alloy of claim 1 , wherein said elastomer is a copolymer of isobutylene and paramethylstyrene, and is optionally halogenated.
11. The alloy of claim 1 , wherein the thermoplastic resin is selected from the group consisting of polyamides, polyimides, polycarbonates, polyesters, polysulfones, polylactones, acrylonitrile-butadiene-styrene resins, polyphenylene sulfide, styrene-acrylonitrile resins, styrene maleic anhydride resins, aromatic polyketones, ethylene vinyl acetates, ethylene vinyl alcohols, and mixtures thereof.
12. The alloy of claim 1 , wherein the elastomer is present in the alloy in an amount in the range of 2 to 90 weight percent.
13. The alloy of claim 1 , wherein the total amount of the anhydride functionalized oligomer and the plasticizer is present in an amount of 5 phr to 35 phr based on the amount of the isobutylene-containing elastomer in the alloy.
14. The alloy of claim 1 , wherein the oligomer has an anhydride level of 5 to 25 wt %.
15. A dynamically vulcanized alloy comprising the following components:
a) at least one isobutylene-containing elastomer;
b) at least one polar thermoplastic resin,
c) an anhydride functionalized oligomer wherein the oligomer has a molecular weight, prior to functionalization, in the range of 750 to 1250 and the anhydride functionality is grafted to the polar thermoplastic resin, and
d) a plasticizer, the plasticizer comprising a component selected from the group consisting of tertiary amines, secondary diamines, and sulfonamides,
wherein the total amount of anhydride functionalized oligomer and the plasticizer is present in an amount of 5 phr to 35 phr based on the amount of the isobutylene-containing elastomer in the alloy, and the anhydride functionalized oligomer and the plasticizer are present in a ratio ranging from 0.15 to 3.0, and
wherein the elastomer is present as a dispersed phase of small vulcanized or partially vulcanized particles in a continuous phase of the thermoplastic resin.
16. The alloy of claim 15 wherein the elastomer is present in the alloy in an amount in the range of 2 to 90 weight percent.
17. The alloy of claim 15 wherein the anhydride functionality is either a succinic anhydride or a maleic anhydride and the oligomer is selected from the group consisting of an alkyl, an aryl, and an alkenyl oligomer.