A polymer dispersion comprising an aqueous, continuous phase and dispersed particles
of polyurethane, which is based on organic, non-aromatic isocyanates with a functionality
of at least 2, said polyurethane having a high degree of crystallinity and whose
crystalline phase has a melting point between 25 and 70 C., and a copolymer
and/or terpolymer having a Tg (glass transition temperature) between
-;20 and +50 C. obtainable by emulsion polymerization of ethylenically unsaturated
monomeric materials containing only C, H, O and/or N atoms, which monomeric materials
comprise from 0.5 to 15 percent on the total of monomeric materials of monomers
containing at least one nitrile group, in a weight ratio between 50:50 and 10:90
(polyurethane to emulsion polymer), in which the particles of the dispersion are
in the form of multiphase particles comprising said polyurethane and said copolymer
and/or terpolymer and which dispersion is obtainable by emulsion polymerization
of the monomeric materials in the presence of the polyurethane dispersion, said
eventual polymer dispersion having a solids content of 30 to 70%. The invention
also comprises the use of these dispersions as an adhesive, especially for heat
seal laminating, preferably for 3-D(imensional) Laminating. The dispersion is also
useful as a size for glass fibers.
