| 摘要 |
NEW MATERIAL:3,9-Bis[2-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]- 1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane represented by the formula and having novel crystal structure characterized by sharp X-ray diffraction peaks at diffraction angles of 2theta=4.2 deg. and 2theta=10.6 deg. measured by X-ray diffrac tion with Cu-K wavelength X-ray. USE:Agent for preventing the softening, embrittlement, surface cracking, discoloration, etc., of various synthetic resins by the action of heat, light and oxygen during processing or use. PREPARATION:The hydroxyphenylpropionic acid ester of formula is dissolved in a recrystallization solvent consisting of 1pt.wt. of a water-soluble solvent (e.g. methanol, isopropanol, etc.) and 0-3pts. of water or consisting of a 5-10C cyclic aliphatic hydrocarbon (e.g. cyclohexane) and the titled crystal is precipitated from the solution at >=40 deg.C.
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