Abstract:
PROBLEM TO BE SOLVED: To provide an aqueous dispersion of a water-soluble polymer.SOLUTION: In the aqueous dispersion of a water-soluble polymer of N-vinylformamide and/or N-vinylacetamide, the dispersion includes, based on 100 pts.mass of water, (A) 5-80 pts.mass of a polymer that is water-soluble, includes an N-vinylformamide unit and/or an N-vinylacetamide unit, and has a particle size of 50 nm-2 μm, and (B) 1-50 pts.mass of at least one polymeric dispersant that is incompatible with the water-soluble polymer (A) in an aqueous solution.
Abstract:
The present invention relates to a process of making paper or paperboard in which a cellulosic thin stock is provided and subjected to one or more shear stages and then drained and a moving screen to form a sheet which is dried, wherein the process employs a retention system which is applied to the thin stock, said retention system comprising as components i) a blend of different cationic polymers and ii) a microparticulate material, in which the blend of cationic polymers comprises, a) a cationic polymer having a charge density of at least 3 mEq per gram and a molar mass of greater than 700,000 Da, b) a cationic polymer having a charge density of below 3 mEq per gram and an intrinsic viscosity of at least 3 dl/g, wherein one of the components of the retention system is dosed into the thin stock after the final shearing stage and the other is dosed into the thin stock before the final shearing stage.
Abstract:
Process for the Manufacture of Paper and Paperboard The present invention relates to a process of making paper or paperboard in which a cellulosic thin stock is provided and subjected to one or more shear stages and then drained and a moving screen to form a sheet which is dried, wherein the process employs a retention system which is applied to the thin stock, said retention system comprising as components i) a blend of different cationic polymers and ii) a microparticulate material, in which the blend of cationic polymers comprises, a) a cationic polymer having a charge density of from 0.5 and below 3 mEq per gram and a molar mass of greater than 700,000 Da, which cationic polymer is selected from polymers containing vinyl amine units and polyethylenimine, b) a cationic polymer having a charge density of below 3 mEq per gram and an intrinsic viscosity of at least 3 dl/g, wherein one of the components of the retention system is dosed into the thin stock after the final shearing stage and the other is dosed into the thin stock before the final shearing stage.
Abstract:
Process for the Manufacture of Paper and Paperboard The present invention relates to a process of making paper or paperboard in which a cellulosic thin stock is provided and subjected to one or more shear stages and then drained and a moving screen to form a sheet which is dried, wherein the process employs a retention system which is applied to the thin stock, said retention system comprising as components i) a blend of different cationic polymers and ii) a microparticulate material, in which the blend of cationic polymers comprises, a) a cationic polymer having a charge density of from 0.5 and below 3 mEq per gram and a molar mass of greater than 700,000 Da, which cationic polymer is selected from polymers containing vinyl amine units and polyethylenimine, b) a cationic polymer having a charge density of below 3 mEq per gram and an intrinsic viscosity of at least 3 dl/g, wherein one of the components of the retention system is dosed into the thin stock after the final shearing stage and the other is dosed into the thin stock before the final shearing stage.
Abstract:
Process for the Manufacture of Paper and Paperboard The present invention relates to a process of making paper or paperboard in which a cellulosic thin stock is provided and subjected to one or more shear stages and then drained and a moving screen to form a sheet which is dried, wherein the process employs a retention system which is applied to the thin stock, said retention system comprising as components i) a blend of different cationic polymers and ii) a microparticulate material, in which the blend of cationic polymers comprises, a) a cationic polymer having a charge density of from 0.5 and below 3 mEq per gram and a molar mass of greater than 700,000 Da, which cationic polymer is selected from polymers containing vinyl amine units and polyethylenimine, b) a cationic polymer having a charge density of below 3 mEq per gram and an intrinsic viscosity of at least 3 dl/g, wherein one of the components of the retention system is dosed into the thin stock after the final shearing stage and the other is dosed into the thin stock before the final shearing stage.
Abstract:
Un proceso de fabricación de papel o cartón en el que se proporciona una materia prima celulósica diluida y se somete a una o más etapas de cizallamiento y luego se drena y en un tamiz móvil se forma una hoja que se seca, en el que el proceso emplea un sistema de retención que se aplica a la materia prima diluida, comprendiendo dicho sistema de retención como componentes, I) una mezcla de diferentes polímeros catiónicos y II) un material en forma de micropartículas, en el que la mezcla de polímeros catiónicos comprende, a) un polímero catiónico que tiene una densidad de carga de al menos 3 mEq por gramo y una masa molar superior a 700.000, en el que el polímero catiónico (a) se selecciona del grupo que consiste en polietileniminas, polietileniminas modificadas, polivinilaminas y polivinil carboxamidas parcialmente hidrolizadas, b) un polímero catiónico que tiene una densidad de carga inferior a 3 mEq por gramo y una viscosidad intrínseca de al menos 4 dl/g, en el que el polímero catiónico (b) comprende entre 5 y 40 % en moles de un monómero catiónico seleccionado del grupo que consiste en poliacrilamidas catiónicas que comprenden acrilamida y una sal de amonio cuaternario de cloruro de metilo de dimetilamino etil acrilato, y en el que uno de los componentes del sistema de retención se dosifica en la materia prima diluida después de la etapa final de cizallamiento y el otro se dosifica en la materia prima diluida antes de la etapa final de cizallamiento.
Abstract:
The present invention relates to a process of making paper or paperboard in which a cellulosic thin stock is provided and subjected to one or more shear stages and then drained and a moving screen to form a sheet which is dried, wherein the process employs a retention system which is applied to the thin stock, said retention system comprising as components i) a blend of different cationic polymers and ii) a microparticulate material, in which the blend of cationic polymers comprises, a) a cationic polymer having a charge density of at least 3 mEq per gram and a molar mass of greater than 700,000 Da, b) a cationic polymer having a charge density of below 3 mEq per gram and an intrinsic viscosity of at least 3 dl/g, wherein one of the components of the retention system is dosed into the thin stock after the final shearing stage and the other is dosed into the thin stock before the final shearing stage.
Abstract:
The present invention relates to a process of making paper or paperboard in which a cellulosic thin stock is provided and subjected to one or more shear stages and then drained and a moving screen to form a sheet which is dried, wherein the process employs a retention system which is applied to the thin stock, said retention system comprising as components i) a blend of different cationic polymers and ii) a microparticulate material, in which the blend of cationic polymers comprises, a) a cationic polymer having a charge density of at least 3 mEq per gram and a molar mass of greater than 700,000 Da, b) a cationic polymer having a charge density of below 3 mEq per gram and an intrinsic viscosity of at least 3 dl/g, wherein one of the components of the retention system is dosed into the thin stock after the final shearing stage and the other is dosed into the thin stock before the final shearing stage.