| 摘要 |
<p>@ A method of producing polymers of the polyurethane type without using isocyanates, characterized in that compounds containing active atoms of hydrogen, preferably oligoesterols or oligoetherols, are amidated with isocyanic acid, preferably obtained "in statu nascendi", and then amide compounds thus obtained, preferably oligourethanes, oligoallophanates or oligourethanallophates, are condensed with an aldehyde in a medium with a pH of not higher than 10 until a polymer is obtained.</p><p>It is preferable to amidate oligoesterols or oligoetherols with isocyanic acid obtained from urea in the presence of hydrochloride of a tertiary amine. Oligourethanes, oligoallophanates or oligourethanallophanates can be condensed alone with formaldehyde or in the presence of other compounds able to react with formaldehyde or their hydroxymethyl derivatives.</p> |
