| 摘要 |
A flexible polyurethane foam composition suitable for cushioning and having substantially the density and body of flexible rubber latex foam, which comprises a flexible polyurethane foam material having uniformly dispersed therein from 30 to 200% by weight, based on the weight of the polyurethane portion of the said material, of an inert mineral filler having substantially spherical-shaped particles and a density of at least 2 grams per cubic centimetre and an average particle diameter between 50 and 800 microns, said polyurethane material in the absence of filler being of low density, e.g. normally from 1 to 2 pounds per cubic foot, but when filled having a density substantially that of flexible rubber latex foam, e.g. from 3 to 4 pounds per cubic foot, and having substantially the volume, tensile strength, elongation and load-bearing characteristics of equivalent unfilled foam. The polyurethane foams are obtained by reacting an excess of a specified aromatic polyisocyanate and a long chain polyol, preferably a polyalkylene ether polyol, or a saturated polyester having terminal hydroxy groups in the presence of a catalyst by known methods. The preferred fillers are zircon sand and zircon silicate and other specified fillers are barium sulphate, beach sand, ground quartz, silicon dioxide, zirconium oxide and zinc oxide. The reaction of a mixture of polyols derived from propylene oxide and glycerine and from ethylene oxide and ethylene glycol with a mixture of tolylene di-isocyanates is described wherein a master-batch consisting of the filler and part of the polyol mixture; a catalyst solution consisting of water, triethylenediamine and a silicone surfactant; trichlorofluromethane; the di-isocyanate; and a tin masterbatch consisting of a 1 to 5% solution of stannous octoate in either or both of the polyols are simultaneously blended and introduced into a mould. The fully expanded product was heated and then allowed to cure at room temperature. |
