Imports In 2010, North Korea imported $15M in Buta-1, 3-diene and isoprene, becoming the 0th largest importer of Buta-1, 3-diene and isoprene in the world. At the same year, Buta-1, 3-diene and isoprene was the 0th most imported product in North Korea. North Korea imports Buta-1, 3-diene and isoprene primarily from: N/A.