Tire innerliners having improved cold temperature properties

A cured elastomeric composition for use in a tire innerliner, comprising:

• a. from 50 to 90 phr of at least one isobutylene-based elastomer;
• b. from 1 to 50 phr of natural rubber;
• and
• c. from 1 to 30 phr of at least one hydrocarbon fluid additive, wherein the hydrocarbon fluid additive has a flash point of at least 200° C., a pour point of less than or equal to −15° C., and specific gravity at 15.6° C. of less than or equal to 0.880;
• wherein the cured elastomeric composition has a MOCON permeability coefficient of less than or equal to Z, where Z=0.282X+0.4817 where X is the amount of natural rubber in phr, and wherein the cured elastomeric composition has a brittleness of less than or equal to A, where A=−0.13X−51 where X is the amount of natural rubber in phr.

A process for producing an air barrier comprising the steps of:

• a. combining from 50 to 90 phr of at least one isobutylene-based elastomer, from 1 to 50 phr of natural rubber, and from 1 to 30 phr of at least one hydrocarbon fluid additive, wherein the hydrocarbon fluid additive has a flash point of at least 200° C., a pour point of less than or equal to −15° C., and specific gravity at 15.6° C. of less than or equal to 0.880;
• b. curing the combined components to form a cured elastomeric composition wherein the cured elastomeric composition has a MOCON permeability coefficient of less than or equal to Z, where Z=0.282X+0.4817 where X is the amount of natural rubber in phr, and wherein the cured elastomeric composition has a brittleness of less than or equal to A, where A=−0.13X−51 where X is the amount of natural rubber in phr;
• and
• c. shaping the cured elastomeric composition to form the air barrier.

An aircraft tire comprising an innerliner which comprises:

• a. from 50 to 90 phr of at least one isobutylene-based elastomer;
• b. from 1 to 50 phr of natural rubber;
• and
• c. from 1 to 30 phr of at least one hydrocarbon fluid additive, wherein the hydrocarbon fluid additive has a flash point of at least 200° C., a pour point of less than or equal to −15° C., and specific gravity at 15.6° C. of less than or equal to 0.880;
• wherein the aircraft tire has a MOCON permeability coefficient of less than or equal to Z, where Z=0.282X+0.4817 where X is the amount of natural rubber in phr, and wherein the cured elastomeric composition has a brittleness of less than or equal to A, where A=−0.13X−51 where X is the amount of natural rubber in phr.