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Isotactic Polybutene Granules from Japan

Isotactic polybutene granules, a stereoregular polymer of butene with high crystallinity, fall under HTS 3902.90.0050 as 'other' primary olefin polymers (>95% butene content). Used in films and molded parts for its strength and chemical resistance. Classified per note (a)(1) for named poly- prefixes.

Duty Rate — Japan → United States

12.5%

Rate breakdown

9903.05.4912.5%Section 301 (forced labor) — Japan (col1 rate < 12.5 percent): MFN < 12.5% → total duty capped at 12.5%

Import Tips

Include stereochemistry details in technical data sheets for CBP review

Segregate from polyethylene shipments to prevent co-mingling errors

Watch for moisture content affecting primary form integrity