| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a stabilizer containing chlorine in a small amount which is suitable for stabilizing an organic material against decomposition caused by oxidation, heat or light. SOLUTION: This method is a producing method concerning the reaction of biphenyl in a low-chlorine stabilizer mixture with both of phosphorus trichloride and aluminum trichloride by Friedel-Crafts reaction and then the reaction of the reaction product with 2,4-di-tert-butylphenol in the presence of a tertiary amine or an aromatic amine and a solvent while separating two layers formed, and comprises solvent-layer treatment with water, a base and a desiccant, separation of precipitate from a stabilizer mixture-containing solution and solvent evaporation. The stabilizer mixture comprises (a) 50-80 wt.% of tetrakis(2,4-di- tert-butylphenol)biphenylene diphosphonite and its isomer, (b) 5-25 wt.% of bis(2,4-di-tert-butylphenol)biphenylene monophosphonite and its isomer and (c) 5-25 wt.% of tris(2,4-di-tert-butylphenol) phosphonite, and the total content of the ingredients (a), (b) and (c) is not more than 100 wt.%.
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