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US 6,605,736 B1Granted
Process for the preparation of condensed phosphoric esters
AssigneeDaihachi Chemical Industry Co., Ltd.
InventorsShin Nakamura, Kazuo Noguchi, Taku Fujisawa, Takafumi Ohkawa
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Abstract
A condensed phosphoric ester having a very low content of volatile components is provided by a process including a first step of reacting a phosphorus oxytrihalide with a bisphenol-based compound to prepare a phosphorohalidate; a second step of removing unreacted phosphorus oxytrihalide; and a third step of reacting the phosphorohalidate with a monophenol-based compound at a specific ratio.
Claims8
A process for preparing a condensed phosphoric ester, comprising:
- a first step of reacting a phosphorus oxytrihalide with a bisphenol-based compound to prepare a phosphorohalidate;
- a second step of removing unreacted phosphorus oxytrihalide remaining after the first step;
- and
- a third step of reacting the phosphorohalidate with a monophenol-based compound in a stoichiometrically excess amount with respect to the phosphorohalidate,
- wherein the amount of the monophenol-based compound in the third step is greater, by equal to or less than 2 mol %, than the theoretically necessary amount for turning the entire amount of the phosphorohalidate into the condensed phosphoric ester.
2 more elements
Dependencies are inferred from the claim text.