摘要 |
<p>1,250,266. Laminates. AMERICAN CYANAMID CO. 11 Nov., 1969 [20 Dec., 1968], No. 55213/69. Heading B5N. [Also in Divisions B1-B2 and C3] A polyurethane based adhesive composition for use in bonding together woven and non- woven fabrics, and plastic sheeting or foams, particularly those of PVC or polyurethane, comprises the product formed by thickening a water chain-extended isocyanate-terminated prepolymer obtained by reacting an aromatic diisocyanate having the isocyanate groups directly attached to the aromatic ring with less than the equivalent amount of a mixture of two glycols, one of which is a non-polymeric glycol containing a pendant carboxyl group, and the other being a polyalkylene ether glycol. In examples an isocyanate-terminated prepolymer is prepared by reacting tolylene di-isocyanate with a polypropylene glycol and 2,2-bis(hydroxymethyl)- propionic acid, is chain-extended with water in presence of triethylamine, thickened with a polyacrylic-type thickening agent, and used to bond a woven wool fabric and a cellulose acetate tricot to opposite sides of a sheet of polyurethane foam. Alternatively, the same adhesive or a mixture thereof with partially methylated trimethylol melamine, is applied through a perforated template to a woven wool fabric and the latter is then bonded to cellulose acetate tricot using the pressure provided by the weight of a sheet of plate glass. In use it is necessary to dry and cure the adhesive, e.g. by heating to between 250‹ and 350‹ C.</p> |