本发明提供了一种脱氯剂及其在降低异氰酸酯中氯含量和色度中的应用，属于异氰酸酯制造领域。本发明的脱氯剂是以纳米二氧化硅为基体，通过含有碱性功能基团的乙烯基吡啶和9-十八烯胺以及硅烷偶联剂对二氧化硅表面进行接枝共聚改性制得，功能基团为吡啶基和胺基。将该脱氯剂填充至固定床吸附塔中处理粗异氰酸酯，通过化学解离和物理吸附的作用，可显著降低粗MDI或粗TDI氯含量，并明显改善色度。

The invention provides a dechlorinating agent and application thereof in reducing chlorine content and chromaticity of isocyanate, and belongs to the field of isocyanate manufacturing. The dechlorinating agent disclosed by the invention is prepared by taking nano silicon dioxide as a matrix and carrying out graft copolymerization modification on the surface of the silicon dioxide through vinylpyridine containing basic functional groups, 9-octadecene amine and a silane coupling agent, and the functional groups are pyridyl and amido. The dechlorinating agent is filled into a fixed bed adsorptiontower to treat crude isocyanate, and under the action of chemical dissociation and physical adsorption, the chlorine content of crude MDI or crude TDI can be obviously reduced, and the chromaticity is obviously improved.