Thermoplastic elastomer adhesive

DETAILED DESCRIPTION OF THE INVENTION The adhesive composition of the present invention contains two components which can be applied between a thermoplastic elastomer and a substrate under bonding conditions in order to produce an exceptionally high strength, water- and heat-resistant adhesive bond.
The first component of the present invention comprises a linear polyester polyurethane, a halogenated polyolefin and a phenolic resin.
The linear polyester polyurethanes which are an essential element of the invention are typically prepared by reacting isocyanate-functional urethane polyester prepolymers with low molecular weight chain extending diols employing conventional techniques well known in the art.
An extensive description of some of the useful techniques for preparing polyester urethane prepolymers can be found in Saunders and Frisch: "Polyurethanes, Chemistry and Technology," Part II, Interscience, (New York 1964), especially at pages 8 to 49, and in the references cited therein.
Other preparative techniques which are known in the art can also be employed.
More specifically, the linear polyester polyurethanes which can be employed in the adhesive compositions of the present invention typically are prepared by reacting at least one linear polyester having two active hydrogen atoms with a diisocyanate in order to form an isocyanate-functional urethane polyester prepolymer.
The urethane polyester prepolymer is then reacted with a low molecular weight chain extending diol in order to prepare the linear polyester polyurethane useful in the present invention.
The hydrogen atom-containing linear polyesters used to produce the polyurethanes of the invention are generally hydroxy-terminated polyesters having an average molecular weight in the range from about 500 to 4000.
The linear polyesters are typically formed from bifunctional monomers having either aliphatic or aromatic segments therein.
For example, the linear polyesters may be formed by reacting polyhydric alcohols with polycarboxylic acids in hydroxyl:carboxyl ratios ranging from 2:1 to 15:14