| 摘要 |
Paper-like flat elements are prepared by comminuting polyurethane foam in an aqueous medium, mixing the comminuted polyurethane with beaten pulp or cellulose derivative or fibrous synthetic polymeric material and forming a web from the mixture on a paper-making machine. The pieces of polyurethan foam may be comminuted by beating them in a hollander. Fibres of natural cellulose, regenerated cellulose, cellulose acetate or synthetic polymers such as polyacrylonitrile, polyamides or polyesters, cut short, are beaten separately and added to the beaten polyurethane, or may be beaten with the polyurethane. A non-foaming surface-active substance may be added to the polyurethane in the beater or to the mixed pulp. A binder or a wet-strengthening agent may be added to the pulp. The surfaceactive substance may be a mixture of paraffinic hydrocarbons and polyglycol oleate. Wetstrengthening resins may be condensates of polyalkylenepolyamines and epichlorohydrin, melamine-formaldehyde or urea-formaldehyde resins. Binders may be natural or synthetic latices, e.g. of a copolymer of butadiene, acrylonitrile and methacrylic acid, or polychlorobutadiene. The formed sheets can be impregnated with natural or synthetic latices. The products have good heat-insulating and sound-damping properties, and can be used for packaging, as insulating layers, as carpet underlays or as window-leathers.ALSO:Paper-like flat elements are prepared by comminuting polyurethane foam in an aqueous medium, mixing the comminuted polyurethane with beaten pulp or cellulose derivative or fibrous synthetic polymeric material and forming a web from the mixture on a paper-making machine. The pieces of polyurethane foam may be comminuted by beating them in a hollander. Fibres of natural acetate or synthetic polymers such as polyacrylonitrile, polyamides or polyesters, cut short, are beaten separately and added to the beaten polyurethane, or may be beaten with the polyurethane. A non-foaming surface-active substance may be added to the polyurethane in the beater or to the mixed pulp. A binder or a wet-strengthening agent may be added to the pulp. The surface-active substance may be a mixture of paraffinic hydrocarbons and polyglycol oleate. Wet-strengthening resins may be condensates of polyalkylenepolyamines and epichlorohydrin, melamine-formaldehyde or urea-formaldehyde resins. Binders may be natural or synthetic latices, e.g. of a copolymer of butadiene, acrylonitrile and methacrylic acid, or polychloro-butadiene. The formed sheets can be impregnated with natural or synthetic latices. The products have good heat-insulating and sound-damping properties, and can be used for packaging, as insulating layers, as carpet underlays or as window-leathers. |
