| 摘要 |
This invention relates to a method for obtaining materials and products based on urea-formaldehyde resin. Thus, the invention is a method of obtaining composite materials and products, particularly for construction and building purposes, based on urea-formaldehyde resins. It relates particularly to cast materials and products. As the active filler and curing agent for the urea-formaldehyde resin there is used phosphogypsum, which is a by-product of phosphoric acid production and which can be used either moist or dried. Moist phosphogypsum usually contains 40 weight percent of water and is added in up to 40 to 90 weight percent of the overall mixture. The dried phosphogypsum contains only water of crystallization since its "loose" water has been extracted. It is added in quantities of from 30 to 50 weight percent of the overall mixture. This method does not require special temperatures and pressures, i.e., it can be used at atmospheric pressure and at room temperature. Some heating and increased pressure can be used if desired. Depending on the ratio of the initial components, materials of a wide spectrum of physical and mechanical properties can be obtained. The new materials and products find diverse applications in the fields of construction (building) and industry, e.g., for dividing walls, paneling, heat insulation, tubes, adhesive and the like. |
