Process for increasing the wettability of difficult to wet surfaces

摘要

The wettability of hydrophobic solid surfaces of synthetic polymeric substances relative to aqueous fluids is increased by applying to the surface at 15-35 DEG C or incorporating in at least the layer adjacent to the surface, at least one inorganic salt of germanium, tin, lead, titanium, zirconium, hafnium or thorium. The salt may be applied to the surface in aqueous solution, which may contain a detergent, or as a solution in an organic solvent e.g. an alcohol, ketone, ester, ether, or amine, which may also contain an inorganic or organic acid, e.g. tartaric or sulphaminic acids, or as a solution in a water/organic solvent mixture. A solvent may be used which has a solvating action upon the surface, and the surface may be electrically charged before application of the salt. Alternatively, solid salt may be scattered upon the surface, which is then heated to a temperature in the region of the melting point of the polymer, or incorporated in a moulding composition of the polymer. In an Example, nylon fabric is immersed in an aqueous detergent solution of stannous chloride and zirconium oxychloride, rinsed with water and dried.ALSO:The wettability of hydrophobic solid surfaces of synthetic polymeric substances relative to aqueous fluids is increased by applying to the surface at 15 - 35 DEG C, or incorporating in at least the layer adjacent to the surface, at least one inorganic salt of germanium, tin, lead, titanium, zirconium, bafnium or thorium. The salt may be applied to the surface in aqueous solution, which may contain a detergent, or as a solution in an organic solvent e.g. an alcohol, ketone, ester, ether, or amine, which may also contain an inorganic or organic acid, e.g. tartaric or sulphaminic acids, or as a solution in a water/organic solvent mixture. A solvent may be used which has a solvating action upon the surface, and the surface may be electrically charged before application of the salt. Alternatively, solid salt may be scattered upon the surface, which is then heated to a temperature in the region of the melting point of the polymer, or incorporated in a moulding composition of the polymer. In Examples (1) polystyrene film is immersed in an aqueous solution of SnCl2, TiCl3 and detergent, rinsed with water and dried; (2) polypropylene film is immersed in an aqueous solution of zirconium oxychloride, TiCl3 and detergent, and rinsed with 1NNaOH and then with water, (3) nylon fabric is treated as in (1) with an aqueous detergent solution of stannous chloride and zirconium oxychloride; (4) a moulded article of vinyl formaldehyde resin is treated as in (1) with an aqueous solution containing SnCl2, lead acetate, hydrochloric acid and detergent; (5) polystyrene film is immersed in aqueous detergent containing zirconium oxychloride, and then rinsed in 1NNaOH; (6) polypropylene film is treated as in (1) with an aqueous solution containing germanium dichloride, hydrochloric acid and detergent; (7) polypropylene film is immersed in a solution of stannous chloride in propylene glycol; (8) polystyrene film is immersed in a solution of stannous chloride in acetone. Surfaces of polymeric materials such as polypropylene and polyethylene thus treated show improved wettability with respect to printing inks.