PREPARATION OF ORGANIC PHOSPHORUS DERIVATIVE OF 2,4-DI-TERT-BUTYLPHENOL AND ORGANIC PHOSPHORUS DERIVATIVE OF BIPHENYL 4,4-DIHALOMAGNESIUM COMPOUND AND USE OF SAID ORGANIC PHOSPHORUS DERIVATIVE FOR STABILIZATION OF PLASTICS, ESPECIALLY POLYOLEFINE MOLDING COMPOSITION

摘要

Process for the preparation of organophosphorus derivatives of 2,4-di-t-butylphenol having a high content of organophosphorus derivatives of biphenyl, characterised in that, in the first step, a 4,4'-dihalobiphenyl whose halogen has an atomic weight of at least 35 is reacted under Grignard conditions with magnesium to give the corresponding Grignard compound, which is further reacted, in a second step, with bis(2,4-di-t-butylphenyl) chlorophosphite of the formula IV …IMAGE… to form a mixture in which at least 50% by weight of the phosphorus is bound in the form of tetrakis(2,4-di-t-butylphenyl)-4,4'-biphenylene diphosphonite of the formula I …IMAGE… the bonding of the phosphorus being determined by 31P-NMR analysis. …??The invention furthermore relates to a polyolefin moulding composition which contains tetrakis(2,4-di-t-butylphenyl)- 4,4'-biphenylene diphosphonite of the formula I prepared by reacting a 4,4'-dihalobiphenyl whose halogen has an atomic weight of at least 35, with magnesium to give the Grignard compound and subsequent reaction thereof with bis(2,4-di-t-butylphenyl) chlorophosphite. …??The moulding composition has improved properties compared with moulding compositions which contain said phosphonite prepared in accordance with the prior art. …??The invention also relates to a process for the preparation of 4,4'-dihalomagnesium compounds of biphenyl by reacting a 4,4'-dihalobiphenyl whose halogen has an atomic weight of at least 35 with magnesium in the absence of an entrainer, in which process a 4,4'-dihalobiphenyl whose halogen has an atomic weight of at least 35 is reacted with finely divided magnesium kept in suspension.