Abstract:
PROBLEM TO BE SOLVED: To provide an improved method for producing a copolymer which is created by copolymerizing at least one hydrophilic N-vinyllactam and at least one hydrophobic comonomer and which is soluble in water to become a clear solution by free radical copolymerization in an organic solvent.SOLUTION: After 70-99 wt.% of used N-vinyllactam is transformed, a combination of: distilling 3-30% of the reaction mixture away and continuing polymerization in the same solvent; and performing the polymerization under pressure so as to avoid evaporation of components, is performed.
Abstract:
PROBLEM TO BE SOLVED: To provide methods for producing vinyllactam copolymers, which comprise causing radical polymerization of water-soluble N-vinyllactam and hydrophobic comonomers in an organic solvent in the presence of an initiator. SOLUTION: The following process measures are combined appropriately and comprise (i) performing polymerization under reflux, (ii) adding at least 5 mol% of N-vinyllactam to the polymerization mixture if at least 70 mol% of the total amount of hydrophobic monomer used have completely reacted, (iii) returning the condensate formed in the reflux from below to the polymerization mixture, (iv) introducing the initiator in the form of a solution in an organic solvent from below into the polymerization mixture, (v) adding N-vinyllactam to the reflux, (vi) distilling off a portion of the solvent and continuing polymerization following conversion of 70 to 99% by weight of the N-vinyllactam used, (vii) introducing at least one monomer from below into the polymerization mixture, and (viii) performing polymerization under pressure so as to avoid vaporization of the component. COPYRIGHT: (C)2008,JPO&INPIT
Abstract:
Mezcla conteniendo A) al menos un copolímero , obtenible mediante (i) polimerización por disolución radicalmente iniciada de una mezcla monomérica de (a) del 0,01 al 99,99% en peso de al menos un monómero, seleccionado del grupo, compuesto por los N-vinilimidazoles y dialilaminas, si fuera necesario, en forma parcial o totalmente cuaternizada; (b) del 0,01 al 99,99% en peso de al menos un monómero hidrosoluble neutro o básico diferente de (a); (c) del 0 al 50% en peso de al menos un ácido insaturado o de un anhídrido insaturado; (d) del 0 al 50% en peso de al menos un monómero radicalmente copolimerizable diferente de (a), (b) o (c); y (e) del 0,01 al 10% en peso de al menos un monómero que actúa como reticulante con al menos dos dobles enlaces no conjugados etilénicamente insaturados, y (ii) posterior cuaternización o protonación parcial o total del polímero para el caso de que el monómero (a) no esté cuaternizado o sólo parcialmente y B) al menos un filtro UV inorgánico.