Jihua Group Company Fine Chemicals Factory (High Activity)
Weifang Binhai Petrochemical Co., Ltd. (high activity)
Jinzhou jinglian lube oil additive co., ltd
Lanzhou Luborun Lanlian Additive Co., Ltd.
Xinjiang Xinfeng chemical co., ltd
Hangzhou shunda group new material co., ltd.
Nantong kaitai polymer material co., ltd
Only Hangzhou Shunda Group New Materials Co., Ltd. is from Zhejiang. Nantong kaitai polymer material co., ltd is from Jiangsu, which is very close to Zhejiang. Everything else is from the north. One of them is from Shandong.
Baidu search: polyisobutylene, you can find many companies, there are several in Guangzhou, but they seem to be agents. You are a professional in this field, you need to find it yourself.