Abstract: A process for producing paper or board, which process comprises ad-mixing (I) an aqueous composition of pH ?6 and (II) at least one water-soluble polymeric anionic compound to a paper stock having a pH in the range from 6 to 8 and then dewatering the paper stock by sheet formation and drying, wherein the aqueous composition comprises (a) polymers having primary amino groups and/or amidine groups to a combined content for these groups of ?1.5 meq/g of polymer, and (b) 0.01 to 50 mol % of 1,4-cyclohexanedione (b) based on the combined amount of primary amino groups and/or amidine groups of the polymers, and also to the paper or board thus obtained.

Abstract: The invention relates to an aqueous composition comprising (a) polymers having primary amino groups and/or amidine groups to a combined content for these groups of ?1.5 meq/g of polymer, and (b) 0.01 to 50 mol % of 1,4-cyclohexanedione (b) based on the combined amount of primary amino groups and amidine groups of the polymers, wherein the pH of the aqueous composition is ?6, and further to its use as strength enhancer and to a method of producing paper and board, employment of the aqueous composition and also the paper and board thus obtained.