Preparations of a polyurethane and/or polyurea and a copolymer which are hydrophobic contain at least one conversion product (S), at least one copolymer (C), optionally at least one (blocked) polyisocyanate, optionally a solvent, and optionally at least one surface-active substance. The conversion product (S) may be the reaction product of at least one compound (A) with at least one unblocked or at least partially blocked di-, tri- or polyisocyanate (IC). The compound A may be the reaction product of a polyhydric alcohol with a carboxylic acid or with an alkylisocyanate, or a reaction product of an alkanolamine and/or alkylamine (a3) with a carboxylic acid and/or alkylisocyanate. The highly hydrophobic preparations may be applied to textiles without negatively influencing a subsequent adhesion of the textile substrate or the membrane permeability of the substrate even after thermal treatment, and exhibit very good wash permanence on the substrates.