Patent GB-997334-A (GB)
Title: Improvements relating to cellular materials
Inventor: MERRIMAN PETER
IPC: C08J9/32
Filed: 1962-01-11
Abstract: A resilient cellular material comprises rigid cellular bodies of glass or synthetic resin bonded by a resilient cross-linked cellular material.  It may be produced by forming a dispersion of the rigid bodies in a fluid precursor of the resilient material before, during or after foaming and subsequently cross-linking the material.  The invention may be applied to the making of latex foam rubber, polyurethane foam or vinyl resin foam.  The rigid bodies may be microballoons, i.e. expanded particles of glass or synthetic resin, e.g. urea-formaldehyde or phenol-formaldehyde resin of 2-100 microns diameter, and may be nitrogen filled. They may also be fragments of expanded polystyrene, cellular ebonite or rigid cellular polyurethane of 0.1-40 mm. diameter and may be fibre shaped.  The fragments may be treated with a solvent, detergent or catalyst, e.g. a tertiary amine or ferric acetylacetonate to increase adhesion.  Less than 30% of non-cellular materials, e.g. rayon fibres and vulcanized rubber may also be incorporated into the mix.  The rigid cellular bodies may be added to the extent of 1/4 -30%, to a synthetic resin mix prior to curing or to particles of cured resilient foam prior to bonding with an adhesive.  In the latter case, 1-30% of the cellular material should be rigid.  The adhesive should be a foamable or non-foamable polyurethane forming composition, or a liquid organic polysulphide plus an epoxy resin and a rubber latex and should constitute 1/13 -\ba1/3 of the mixture.  The mixture is compounded by compressing it to 50-95% of its initial volume.  In Example 1, ureaformaldehyde resin microballoons are stirred into polypropylene glycol. Polyurethane foamed is prepared by adding water-soluble silicone, water, diazabicyclooctane, stannous octoate, N-methylmorpholine and tolylene di-isocyanate. In other Examples: (2) nitrogen filled phenol formaldehyde resin microballoons are incorporated into polyurethane foam, (3) urea-formaldehyde microballoons are added to a prepolymer mixture of a polyether triol, triethylene diamine and tolylene di-isocyanate, which is then foamed by adding further tolylene di-isocyanate, polydimethyl - siloxane oil, triethylamine, N-methyl-morpholine and water, (4) phenolformaldehyde microballoons are incorporated into a polyurethane pre-polymer which was subsequently foamed, (5) urea-formaldehyde microballoons are incorporated in a mixture of natural and synthetic rubber latex polymers, potassium oleate, sulphur, N-N1-di-beta-naphthyl-p-phenylen diamine, zinc mercapto benzthiazole and zinc diethyldithio-carbamate which is foamed with addition of further potassium oleate, zinc oxide, lauryl pyridinium chloride and sodium silicofluoride and steam vulcanized, (6) phenol-formaldehyde microballoons are incorporated into rubber latex which is subsequently foamed, (7) and (8) a polyether tetrol stannous octoate and tolylene diisocyanate mixture is used to bind fragments of resilient polyurethane and rigid expanded polystyrene, (9) fragments of resilient polyurethane, rigid expanded polystyrene, rayon fibres and vulcanized rubber are bonded with a polyurethane forming mixture. The products may be used for packing and upholstery. Specifications 869,624, 898,272 and 973,071 are referred to.