The invention relates to a water dilutable resin composition comprising a resin that is a reaction product of an aldehyde and a hydroxyl-aromatic compound, said composition further comprising an amino compound comprising 2 - 6 amino groups and a sugar alcohol, wherein the resin has an initial molar ratio of aldehyde to hydroxyl-aromatic compound from 2.3 to 5.5, a ratio of resin to amino compound plus sugar alcohol of 45:55 to 70:30 parts by weight, a ratio of amino compound to resin between 20:80 and 50:50 parts by weight and a ratio of sugar alcohol to resin plus amino compound is between 5:95 and 30:70 parts by weight. The invention further relates to a process for the manufacture the resin composition, to the use of the resin composition as a binder material for non-woven fibrous material, in particular insulation materials, and to a process for the manufacture of such insulation material.