Abstract: In a process for producing bleached mechanical woodpulp, said process comprising the steps of a) delaminating comparatively large particles of wood, which have optionally been pretreated with chemicals and/or water, into modified particles of wood, b) grinding the modified particles of wood from a) in one or more refiners, c) optionally treating the stalk obtained in step b) with oxidative or reductive bleaching agents, a composition Z is present during step a) and/or step b), said composition Z comprising one or more of the following components (Z1) to (Z3): a salt of dithionous acid H2S2O4 (Z1), a dithionous acid or dithionous acid derivative generator compound (Z2), a salt of sulfurous acid (sulfite) plus sodium tetraborohydride (Z3) and also optionally additives (Z4).

Abstract: In a process for producing bleached mechanical woodpulp, said process comprising the steps of a) delaminating comparatively large particles of wood, which have optionally been pretreated with chemicals and/or water, into modified particles of wood, b) grinding the modified particles of wood from a) in one or more refiners, c) optionally treating the stalk obtained in step b) with oxidative or reductive bleaching agents, a composition Z is present during step a) and/or step b), said composition Z comprising one or more of the following components (Z1) to (Z3): a salt of dithionous acid H2S2O4(Z1), a dithionous acid or dithionous acid derivative generator compound (Z2), a salt of sulfurous acid (sulfite) plus sodium tetraborohydride (Z3) and also optionally additives (Z4).

Abstract: In a process for producing bleached mechanical woodpulp, said process comprising the steps of a) delaminating comparatively large particles of wood, which have optionally been pretreated with chemicals and/or water, into modified particles of wood, b) grinding the modified particles of wood from a) in one or more refiners, c) optionally treating the stalk obtained in step b) with oxidative or reductive bleaching agents, a composition Z is present during step a) and/or step b), said composition Z comprising one or more of the following components (Z1) to (Z3): a salt of dithionous acid H2S2O4 (Z1), a dithionous acid or dithionous acid derivative generator compound (Z2), a salt of sulfurous acid (sulfite) plus sodium tetraborohydride (Z3) and also optionally additives (Z4).

Abstract: In a process for producing bleached mechanical woodpulp, said process comprising the steps of a) delaminating comparatively large particles of wood, which have optionally been pretreated with chemicals and/or water, into modified particles of wood, b) grinding the modified particles of wood from a) in one or more refiners, c) optionally treating the stalk obtained in step b) with oxidative or reductive bleaching agents, a composition Z is present during step a) and/or step b), said composition Z comprising one or more of the following components (Z1) to (Z3): a salt of dithionous acid H2S2O4 (Z1), a dithionous acid or dithionous acid derivative generator compound (Z2), a salt of sulfurous acid (sulfite) plus sodium tetraborohydride (Z3) and also optionally additives (Z4).

Abstract: A method of producing cellulose from lignocellulosic material by sulfite digestion or sulfate digestion in the presence of a salt of dithionous acid comprises using the salt of dithionous acid in an amount from 0.1 to 4.0 wt. % based on the amount of oven-dry lignocellulosic material.

Abstract: A method of producing cellulose from lignocellulosic material by sulfite digestion or sulfate digestion in the presence of a salt of dithionous acid comprises using the salt of dithionous acid in an amount from 0.1 to 4.0 wt. % based on the amount of oven-dry lignocellulosic material.

Abstract: A process for the production of singly and/or multiply coated paper and/or board, except for photographic papers and self-adhesive labeling papers, which are particularly suitable for printing, packaging and inscription, is described. The substrate, for example base paper or board, is coated once or several times with a free-falling liquid curtain, the coating liquid having in particular an extensional viscosity of from 1 to 1000 Pa·s at a Hencky strain of from 1 to 15.

Abstract: A coating slip composition which can be applied by the curtain coating method to substrates to be coated, for example base paper or cardboard, is described. The substrate, which may be base paper or cardboard, is coated with one or more free-falling liquid curtains, a binder being added to the coating liquid. The binder is selected from the group comprising styrene/butadiene latex binders, styrene/acrylate latex binders, styrene/butadiene/acrylonitrile latex binders, styrene/maleic anhydride binders and styrene/acrylate/maleic anhydride binders, the binder having a particle size of <130 nm.

Abstract: A process for the production of singly and/or multiply coated paper and/or board, except for photographic papers and self-adhesive labeling papers, which are particularly suitable for printing, packaging and inscription, is described. The substrate, for example base paper or board, is coated once or several times with a free-falling liquid curtain, the coating liquid having in particular an extensional viscosity of from 1 to 1000 Pa·s at a Hencky strain of from 1 to 15.

Abstract: A coating slip composition which can be applied by the curtain coating method to substrates to be coated, for example base paper or cardboard, is described. The substrate, which may be base paper or cardboard, is coated with one or more free-falling liquid curtains, a binder being added to the coating liquid. The binder is selected from the group comprising styrene/butadiene latex binders, styrene/acrylate latex binders, styrene/butadiene/acrylonitrile latex binders, styrene/maleic anhydride binders and styrene/acrylate/maleic anhydride binders, the binder having a particle size of <130 nm.