Composition for improving the mechanical and surface properties of paper or cardboard, comprises gelatin and a mixture of diatomaceous earth and surfactant

摘要

Compositions (I) containing (A) 20-80 wt% gelatin and (B) 20-80 wt% of a mixture of (b1) diatomaceous earth and (b2) surfactant. Independent claims are also included for: (1) a method (M1) for improving the mechanical properties of paper or cardboard sheets by adding (I) to the refined paper pulp (2) a method (M2) for improving the surface properties of paper or cardboard by treatment in the size-press, involving the application of an aqueous suspension of (I) to one or both sides of the paper or cardboard sheet.