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:
Oct. 05, 1999
Filed:
Mar. 30, 1998
Parshuram Gajanan Shukla, Maharashtra, IN;
Swaminathan Sivaram, Maharashtra, IN;
Natarajan Rajagopalan, Madras, IN;
Council of Scientific & Industrial Research, New Delhi, IN;
Abstract
The present invention relates to a process for the preparation of polyurethane microcapsules containing monocrotophos, which comprises of preparing a solution of diol or polyol having a molecular weight in the range of 200-2000, crosslinker, monocrotophos and a catalyst selected from amino or organometallic compounds; dispersing this solution into a dilute solution of stabilizer which consists of a block copolymer having the general formula �A!.sub.n -�B!.sub.m where A and B are chemically and compositionally dissimilar segments where n and m segments are in between 30-115 and 10-60 units respectively, such that the sum of n and m does not exceed 175 units, in an aliphatic hydrocarbon; adding an isocyanate dropwise to this dispersion; agitating the mixture at 1000-1400 revolutions per minute for the first 6-8 hours and then at 500-800 revolutions per minute for an additional period of 14-18 hours at a temperature between 30.degree. to 40.degree. C. to permit the formation of polyurethane microcapsules; heating the dispersion for an additional period of 1-2 hours at a temperature not exceeding 50.degree. C.; filtering the microcapsules; washing the microcapsules with lower aliphatic hydrocarbon and drying the microspheres under vacuum at temperature between 20.degree. to 35.degree. C.