STERIC HINDERED PHENOLS HAVING ANTIOXIDANT PROPERTIES, METHODS FOR THEIR PRODUCTION, METHOD FOR PRODUCTION OF POLYOLEFINS Russian patent published in 1995 - IPC

FIELD: organic chemistry. SUBSTANCE: desired steric hindered phenols have formula I where R₁ and R₂ are substituents as mentioned below, R₃ is hydrogen atom or lower alkyl, n=0-3 or A is (R₁R₂) where R₁ and R₂ are steric hindered substituents; R₁ having formula II and R₂ is identical to R₁ or it has formula III. In these formulae X and X′ are the same or different and represent oxygen atom, each of R₄, R₅, R₆, R₇ is C₁-C₈-alkyl or R₄ and R₆ may be additionally hydrogen atom and R₈ is hydrogen, methyl or ethyl. Antioxidants are prepared by interaction of bisubstituted phenol and appropriate β- or g-unsubstituted norbornenon in alcohol medium with the help of basic catalysis. Proposed phenol antioxidants are used for production of polyolefins, the process is carried out by polymerization of a-olefins or by their copolymerization and/or by copolymerization with dienes, mass ratio phenol antioxidant and monomer being 0.1:(40-100). (Co)polymerization is carried out till content of phenol said phenol oxidant being bound with said (co)polymer is 0.05-20 mass per 100 mass of (co)polymer. Structures of compounds having formulae II and III are given in specification. EFFECT: improves quality of desired product, improves efficiency of method. 9 cl, 1 dwg, 13 tbl