Back to results
US 3,992,562 AGranted
Manufacture of insoluble and only slightly water-swellable polymers of N-vinyl lactams of improved adsorptivity
AssigneeBASF SE
InventorsWalter Denzinger, Ernst Hofmann, Karl Herrle
Life of this patent
Estimating the term…
Abstract
Manufacture of insoluble polyvinyl lactams by polymerization in the absence of oxygen and in the presence of sulfur compounds having a functionality of less than 6.
Claims7
A process for the manufacture of insoluble and only slightly swellable homopolymers of an N-vinyl lactam or copolymers of two or more vinyl lactams selected from the group consisting of N-vinyl pyrrolidone, N-vinyl caprolactam and N-vinyl piperidone which comprises:
- polymerizing the vinyl lactam or the mixture of vinyl lactams in a dilute aqueous solution of said lactam or lactams at a pH of 6 to 10 with the exclusion of oxygen, said polymerization taking place in the presence of
- a. divinyl ethylene urea, and
- b. from 0.05 to 2% by weight, based on the vinyl lactam of at least one sulfur compound selected from the group consisting of sodium sulfide, sodium sulfite, sodium pyrosulfite, sodium dithionate, sodium sulfoxylate and sodium formaldehyde sulfoxylate.
Dependencies are inferred from the claim text.