PURPOSE: To produce an unsaturated dimer of α-methylstyrenes excellent in preservation stability with good productivity by making an alkali coexist in a reactional solution containing the unsaturated dimer of the α-methylstyrenes, alkalinizing the pH and then distilling the alkalinized reactional solution.
CONSTITUTION: α-Methylstyrenes are reacted in the presence of an aqueous solution of a sulfonic acid compound to afford an unsaturated dimer of the α-methylstyrenes. The sulfonic acid compound which is a catalyst is then removed to make an alkali coexist in the reactional solution. The pH is regulated to ≥8 and the reactional solution is subsequently purified by distillation to provide the high-purity unsaturated dimer of the α-methylstyrenes excellent in preservation stability. α-Methylstyrene is preferred as the α-methylstyrenes. A salt comprising a combination of a weak acid with a strong base is preferably used as the alkali and potassium carbonate is especially preferred as the alkali. This dimer is useful as a molecular weight modifier, etc., in producing a copolymer such as SBR.
SAITO TAKAYUKI
ITO TATSUO
NISHIZAWA HIROSHI
Next Patent: RECOVERY OF CHLOROCARBON FROM GASEOUS MIXTURE