A water soluble package and its method of disposal. The package is provided with thermoplastic polymer side walls which are capable of dissolving in water and aqueous solutions only at temperatures above approximately 37.degree. C.

A method of disposing of utensils after use. The utensils are provided as molded, formed or extruded articles which are only water soluble at temperatures above 37.degree. C. After use, the utensils are subjected to water at a sufficient temperature to substantially dissolve them whereupon the water and dissolved articles are subjected to sewer disposal.

The invention relates to a composite foil, particularly a toilet seat support in which at least one thin, outer normally water-insoluble sealing layer (3) is connected to a less thin water-soluble supporting layer (2) optionally by means of one or more intermediate layers. For obtaining a complete tightness at least the sealing layer (3) is constructed in non-porous manner by extruding a foil from a thermoplastic material. Furthermore, the invention relates to a process and apparatus for the production of the foil by extrusion, preferably with a co-extrusion die.

A composite foil formed from at least two layers in which at least one normally water-insoluble sealing layer comprises a non-porous layer connected to at least one water soluble layer. The water-insoluble layer is soluble in a non-neutral medium and the water soluble layer is (a) water soluble or (b) water insoluble, but soluble in a non-neutral medium.

A PVA-base copolymer is obtained by subjecting a lactone, whose ring is formed of 3 to 10 carbon atoms, to ring-opening polymerization in the presence of polyvinyl alcohol (PVA). The copolymer comprises a PVA chain and an aliphatic polyester grafted as a ring-opened polymer of the lactone on the PVA chain. Further, the copolymer has a PVA content of 2 to 98 wt. %, a polyester content of 98 to 2 wt. %, and a number average molecular weight of 10,000 to 500,000.