| 摘要 |
1. A method of producing flexible phenolic urethane formaldehyde resins, characterized in that at least 94g of phenol is heated along with 30 + 3.33n up to 120 + 3.33 n g of carbamide, where n stands for the water content in the reaction mixture, in the presence of 18.25 + 2.03n up to 73.0 + 2.03n g of hydrogen chloride at the temperature of 373-423 degrees K, until over 50 percent, preferably over 90 percent, of the used hydrogen chloride is transformed into ammonium chloride, and further solvents not containing active hydrogen atoms are added, solution is separated from insoluble substances, added to the multi-hydroxyl alcohol solution, preferably oligomeric, containing 4.25-34 g of hydroxyl groups, possibly phenol is added and (or other monomer reacting with formaldehyde) heated to the temperature of 403-453 degrees K, and then cooled to the temperature not higher than 383 degrees K, from 18.6 to 120 g of formaldehyde is added, preferably in the form of formalin, possibly 0.16 - 0.64 g per each gram of phenol entered additionally to reach the level of over 94 g to the reaction mixture, and up to 30 g of formaldehyde per each gramo-equivalent of reactive spots of other monomer reacting with formaldehyde entered into the reaction mixture and further polycondensation at the temperature of 293-373 degrees K is performed, in the manner typical of novolaks or resols, with pH not exceeding 9.
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