Paper coating slurries for cast coating
AssigneeBASF SE
InventorsDieter Distler, Volker Schadler, Titus Leman, Thomas Steinmacher
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Abstract
A paper coating slip containing a mineral pigment and an aqueous polymer dispersion as a binder, wherein the polymer dispersion is obtainable by emulsion polymerization of ethylenically unsaturated compounds (monomers) and the paper coating slip gels at above 35° C., i.e. the viscosity of the paper coating slip at from 35 to 60° C. is at least twice the viscosity at 30° C.
Claims10
A process for the production of coated papers by coating base papers with paper coating slips comprising a mineral pigment and an aqueous polymer dispersion as a binder, wherein the polymer dispersion is obtainable by emulsion polymerization of ethylenically unsaturated compounds (monomers) and the paper coating slip gels at above 35° C., i.e. the viscosity of the paper coating slip at from 35 to 60° C. is at least twice the viscosity at 30° C., and wherein the coating of the papers is carried out by a cast coating process which comprises the following process steps:
- application of the aqueous paper coating slip to base paper
- bringing of the coated paper into contact with a metal cylinder, in particular a chromium cylinder, heated to at least 90° C.
A paper coating slip comprising a mineral pigment and an aqueous polymer dispersion as a binder, said polymer dispersion being obtainable by emulsion polymerization of ethylenically unsaturated compounds (monomers), said paper coating slip gelling at above 35° C., i.e. the viscosity of the paper coating slip rising between 35 and 60° C. to at least twice the value compared with the viscosity at 30° C., and said paper coating slip comprising a polymeric compound a) having a temperature-dependent light transmittance, temperature-dependent transmittance meaning that there is a temperature range bounded by the temperatures T1 (lower temperature) and T2 (higher temperature) in which the light transmittance decreases to less than 80% of the light transmittance at T1, and these compounds a), owing to their temperature-dependent solubility in water, having a corresponding turbidity range T1 to T2 (coagulescence).
Dependencies are inferred from the claim text.