ALTERNATIVE METHOD OF PRODUCING BISPHENOL A DICYANATE PREPOLYMER Russian patent published in 2013 - IPC C08G73/06 C08G65/40 

FIELD: chemistry.

SUBSTANCE: method consists of two steps, where at the first step, starting bisphenol A reacts with a cyanuric halide (cyanuric chloride or cyanuric bromide) to form a bisphenol A monocyanate prepolymer, and at the second step, the bisphenol A monocyanate prepolymer reacts with a cyan halide (cyan chloride or cyan bromide) to obtain the desired bisphenol A cicyanate prepolymer.

EFFECT: disclosed method enables partial replacement of the hazardous and poisonous cyan halide with much less hazardous cyanuric halide and also avoid the use at the second step of high temperatures and metal-containing polymerisation catalysts which cut the storage life of the bisphenol A cicyanate prepolymer.

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