GB869624A - Improvements relating to resilient materials - Google Patents

Abstract

A method of making a resilient material comprises the steps of depositing or forming, on fragments of resilient cellular material, a liquid bonding agent derived from (a) an organic compound having at least two -NCX radicals in its molecule, where X represents in the case of each radical either an oxygen atom or a sulphur atom, and (b) an organic compound having a molecular weight (or at least an average molecular weight) within the range 500 to 10000 and having in each of its molecules at least two isocyanate-reactive groupings, and subsequently causing and/or allowing the liquid bonding agent to undergo conversion into a flexible solid reaction product. The fragments of resilient p material may be in the form of "crumb" and may consist of latex foam rubber, expanded rubber, resilient polyurethane foams, and resilient cellular vinyl resin (e.g. of plasticized polyvinyl chloride). The polyurethane foam can be prepared from a liquid polyester, polyesteramide, castor oil, polyglycol or a compound containing polyglycol chains attached to carbon or nitrogen, a polyisocyanate and an activating mixture with optionally a colouring agent and hair in the reaction mixture. The organic compound (a) is preferably a diisocyanate, used with or without a triisocyanate. It may be a compound in which the NCX groups are masked or blocked or one formed by reaction of the polyisocyanate with a di- or trimethylolpropane. As compound (b) there may be used a polyester, polyesteramide, polyether or polythioether, thioplast, polyamide, epoxy resin or a monomeric ester such as a glycerol ester of a hydroxy-acid or a transesterification product of a glyceride, a cross-linking compound such as glycol preferably being present. Compounds (a) and (b) may be deposited separately or as a prepolymer on the cellular material. Solidification may be effected by heating and/or the addition of catalysts, cross-linking agents such as primary diamines and glycols and/or the addition of cross-linking promoting agents such as an alcoholate, ester or alkanolamine chelate derived from titanium, vanadium, zirconium, aluminium or antimony. The mixture of particles and bonding agent can be shaped in moulds or formed into a continuous sheet on a conveyer belt. In typical examples (1) crumbed polyurethane foam is sprayed with a mixture of castor oil and a toluylene diisocyanate/trimethylolpropane reaction product and the treated crumb heated in a mould at 90 DEG C.; (3) a similar process is applied to a mixture of crumbed latex foam, resilient polyurethane foam and expanded synthetic rubber; (4) crumbed latex foam alone is employed; (5) resilient polyurethane foam is sprayed separately but concurrently with a toluylene diisocyanatetrimethylol propane reaction product and with ground-nut oil and the treated crumb is heated at 90 DEG C. to give a bonded product. Specifications 758,918, 776,012, 804,093, 804,094, 836,704, 849,774, 852,025, 857,660, 859,947 and 869,623 also are referred to.ALSO:A method of making a resilient material comprises the steps of depositing or forming, on fragments of resilient cellular material, a liquid bonding agent derived from (a) an organic compound having at least two -NCX radicals in its molecule, where X represents in the case of each radical either an oxygen atom or a sulphur atom, and (b) an organic compound having a molecular weight (or at least an average molecular weight) within the range 500 to 10,000 and having in each of its molecules at least two isocyanate-reactive groupings, and subsequently causing and/or allowing the liquid bonding agent to undergo conversion into a flexible solid reaction product. The fragments of resilient material may be in the form of "crumb" and may consist of latex foam rubber, expanded rubber, resilient polyurethane foams, and resilient cellular vinyl resin e.g. of plasticised polyvinyl chloride. The polyurethane foam can be prepared from a liquid polyester, polyesteramide, castor oil, polyglycol or a compound containing polyglycol chains attached to carbon or nitrogen, a polyisocyanate and an activating mixture with optionally a colouring agent and hair in the reaction mixture. The organic compound "(a)" is preferably a diisocyanate, used with or without a trisocyanate. It may be a compound in which the NCX groups are masked or blocked or one formed by reaction of the polisocyanate with a di- or trimethylolpropane. As compound "(b)" there may be used a polyester, polyesteramide, polyether or polythioether, thioplast, polyamide, epoxy resin or a monomeric ester such as a glycerol ester of hydroxy-acid or a transesterification product of a glyceride, a cross-linking compound such as glycol preferably being present. Compounds "(a)" and "(b)" may be deposited separately or as a prepolymer on the cellular material. Solidification may be effected by heating and/or the addition of cross-linking promoting agents such as an alcoholate, ester or alkanolamine chelate derived from titanium, vanadium, zirconium, aluminium or antimony. The mixture of particles and bonding agent can be shaped in moulds or formed into a continuous sheet on a conveyer belt. In Typical Examples (1) crumbed polyurethane foam is sprayed with a mixture of castor oil and a toluylene diisocyanate/trimethylolpropane reaction product and the treated crumb heated in a mould at 90 DEG C.; (3) a similar process is applied to a mixture of crumbed latex foam, resilient polyurethane foam and expanded synthetic rubber; (4) crumbed latex foam alone is employed; (5) resilient polyurethane foam is sprayed separately but concurrently with a toluylene diisocyanate/trimethylolpropane reaction product and with ground-nut oil and the treated crumb is heated at 90 degrees to give a bonded product. Specifications 758,918, 776,012, 804,093, 804,094, 836,704, 849,774, 852,025, 857,660, 859,947 and 869,623 are referred to.