| 摘要 |
PROBLEM TO BE SOLVED: To obtain a composite brightening agent that, when compounded into a thermoplastic or thermosetting resin, gives a molded article excellent in dichroism and free from defects in external appearance of weld lines without detriment to the weatherability, impact resistance, gloss, etc., by incorporating glossy particles into crosslinked polymer particles having a specified average particle size. SOLUTION: This brightening agent is crosslinked polymer particles (e.g. obtd. from styrene, methyl methacrylate, and divinylbenzene) contg. glossy particles pref. having an average particle size of 5-500μm and selected from among metal powders (e.g. an aluminum powder), nickel sulfate, cobalt sulfate, manganese sulfate, metal oxides, muscovite, biotite, synthetic mica, titanium sulfide-coated mica, etc., and has an average particle size of 5-500μm. The content of the glossy particles is pref. 5-90 wt.%, and the average shape ratio of the agent is pref. 1/4-1/1.
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