The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 18, 2000
Filed:
Oct. 12, 1999
Saehan Industries Incorporation, Kyongsangbuk-Do, KR;
Abstract
Disclosed is a method for the preparation of 3-(hydroxyphenylphosphinyl)-propanoic acid which is commonly used as a flame retardant for polyester resins. The preparation of 3-(hydroxyphenylphosphinyl)-propanoic acid is attained by the condensation of phenylphosphonous dichloride and acrylic acid and the hydrolysis of the condensate. In the condensation, the mole ratio of phenylphosphonous dichloride to acrylic acid is within the range of 1:1.1 to 1:1.25. Under a pressure of greater than 1 atm, acrylic acid is added at 65.about.110.degree.C. at an amount more by 10.about.25 mole % than that of phenylphosphonous dichloride and the condensation is carried out at a temperature of 70.about.100.degree. C. under at greater than 1 atm, to produce 3-(hydroxyphenylphosphinyl)-propanoic acid at high yields with desired color.