Purification of acrylamide via crystallization with centrifugal liquor separation
US4010142A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 15, 1975 |
| Grant date | Mar 1, 1977 |
| Priority date | — |
| Expiry date | Dec 15, 1995 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02B2075/027
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Removal of organic impurities from a dilute solution of aqueous acrylamide is achieved by PA1 A. vacuum stripping of the aqueous acrylamide at > 25.degree. to 50.degree. C to concentrate the aqueous solution to about 80% acrylamide; PA1 B. cooling to about 25.degree. C to produce a slurry of acrylamide crystals; PA1 C. centrifuging the acrylamide crystals to express mother liquor and forming a crystal cake of acrylamide crystals; PA1 D. washing the crystal cake with water wash to produce an aqueous rinse liquor; and PA1 E. recycling the mother liquor and rinse liquor to vacuum stripping, step (a). The recycling of mother liquor from step (c) and rinse liquor from step (d) is effected n times where n = 4-20. This purifying process serves to remove certain nonvolatile and non-ionic organic impurities from the acrylamide monomer which are principally trieneamide together with small amounts of valeramide-.DELTA.-1:3-diene and .delta.-cyano-valeramide-.DELTA.-ene. The present process is designed to lower the concentration of trieneamide to a maximum value of 7.5 ppm. These organic impurities in the past had interfered with the activity of and the production of water-soluble homopolymers…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.