| 摘要 |
Water-soluble films suitable for water-dissolvable packaging comprising a polyurethane polymer having defined amounts of poly(ethylene oxide) (and optionally poly(propylene oxide)) groups and acid (preferably carboxyl) groups at least 50% neutralised with a base, at least a proportion of which is of the non-volatile type, the polyurethane being made by chain extension of a urethane prepolymer. Also water-soluble packaging (sachets, capsules, bags) made from the films and their use in packaging various materials, and a process for the production of aqueous polyurethane solutions which may be used for making such films.
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