Preparation of phenylphosphate esters of 4,4'-biphenol
AssigneeBromine Compounds Ltd.
InventorsOlga Weinberg, Joseph Zilberman
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Abstract
A process for preparing 4,4′-biphenol phenylphosphate ester products is described. These ester products, having low acid value and low contents of phenol and residual catalyst, being flowable powders, and further having excellent physical properties such as heat and hydrolytic stability, are useful as halogen-free, effective flame retardants, particularly in thermoplastic polymer compositions.
Claims30
A 4,4′-biphenol phenylphosphate ester product, comprising at least 98% of esters having the formula
- 4
- wherein “n” is a whole number, said percentage being HPLC area percentage.
A process for preparing an oligomeric 4,4′-biphenol phenylphosphate ester product, which comprises reacting a phosphorus oxychloride with 4,4′-biphenol at 90-120° C., to produce intermediate phosphorochloridates, and subsequently reacting said intermediate phosphorochloridates with excess phenol at 120-180° C.
A process for preparing an oligomeric 4,4′-biphenol phenylphosphate ester product, which comprises reacting 4,4′-biphenol with a mixture of diphenyl chlorophosphate and phenyl dichlorophosphate at 130-200° C.
A process for preparing a monomeric 4,4′-biphenol phenylphosphate ester product, which comprises reacting 4,4′-biphenol with diphenyl chlorophosphate at 130-200° C.
Dependencies are inferred from the claim text.