摘要:
A process for obtaining a cationic polymer is disclosed. The cationic polymer is obtained by polymerization of at least one cationic monomer, at least one crosslinker and optionally further monomers, such as nonionic monomers, associative monomers and/or chain transfer agents. The cationic polymer has an at least bimodal molecular weight distribution with at least one first peak (P1) and at least one second peak (P2), wherein the first peak has a lower average sedimentation coefficient of 100 Sved and the second peak has a higher average sedimentation coefficient of 1000 Sved. The polymerization is carried out in two subsequent steps I) and II). In step II), the crosslinker is either completely absent or present in a very limited amount. Step II) is carried out after the polymerization of step I) is finished or vice versa.
摘要:
The instant invention pertains to a method and a fluid composition for producing contact lenses with improved lens quality and with increased product yield. The method of the invention involves adding a Butylated Polyvinylpyrrolidone into a fluid composition including a lens-forming material in an amount sufficient to reduce an averaged mold separation force by at least about 20% in comparison with that without the Butylated Polyvinylpyrrolidone.
摘要:
A use of a graft copolymer obtained by free-radical polymerization of a monomer mixture comprising N-vinyllactam, vinyl ester, and a polyether for increasing the activity of a pesticide is disclosed. A composition comprising a pesticide and a graft copolymer obtained by free-radical polymerization of a monomer mixture comprising i) 30 to 80% by weight of N-vinylpyrrolidone, N-vinylcaprolactam or mixtures thereof, ii) 10 to 50% by weight of vinyl acetate, and iii) 10 to 50% by weight of a polyether is also disclosed. Furthermore a method for preparing said composition by mixing the pesticide and the graft copolymer and a method for controlling phytopathogenic fungi and/or undesired plant growth and/or undesired attack by insects or mites and/or for regulating the growth of plants are also disclosed.