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:
Feb. 21, 1978
Filed:
Jun. 01, 1976
Karl Heinz Vopel, Kansas City, MO (US);
Friedrich Hellrung, Nievenheim-Ueckerath, DT;
Otto Berendes, Dormagen, DT;
Bayer Aktiengesellschaft, Leverkusen, DT;
Abstract
An O,O-dialkyl-dithiophosphoric acid ester is reacted in two steps with approximately an equimolar amount of chlorine, the first step at about 0.degree. to 80.degree. C with all the reactants supplied, and the second step at about 0.degree. to 100.degree. C with precipitation of sulfur from the disulfur dichloride which is produced as a by-product in the first step and which serves as the chlorinating agent in the second step. Advantageously the first step is carried out continuously in two stages about one-third to two-thirds of the chlorine being supplied continuously to each stage. The first stage is at about 30.degree. to 60.degree. C and the second stage at about 10.degree. to 25.degree. C. The second step is thereafter performed batchwise and the desired product is distilled off from the residual sulfur.