| 摘要 |
In a process for producing N-alkoxymethyl polyamides by reacting together a high molecular weight synthetic linear polyamide, formaldehyde and an alcohol in presence of an oxygen-containing acid catalyst having an ionisation constant at least as great as 9.6 X 10-6 and an equivalent conductance measured at 25 DEG C. in .01 N concentration no greater than 370 ohms-1 cm2, the polyamide, formaldehyde and alcohol are mixed and heated to reaction temperature before addition of the acid catalysts. Suitable acid catalysts are phosphoric, p - toluenesulphonic, maleic, oxalic, acetic, formic, or hydroxyacetic. The reaction may be performed at 50-200 DEG C. and at pressures from atmospheric to 500 pounds per square inch. It may be continued for 1 to 200 minutes after addition of the acid. Suitable alcohols are methanol, ethanol, propanol, isopropanol, butanol, olelyl alcohol, lacryl alcohol, benzyl alcohol, ethylene glycol, its methyl ether, methyl glycollate and allyl alcohol. Mixtures of alcohols may be used. 0.1 to 10 parts of formaldehyde are used per part of polyamide. The molecular ratio of formaldehyde to alcohol is preferably between 1 and 1.5, but may vary from 0.1 to 2.0. Paraformaldehyde, trioxane or formaldehyde-liberating substances such as methylal or hexamethylene-tetramine may be used. In an example, pulverized polyhexamethylene adipamide, paraformaldehyde, ethanol and water were mixed and heated to 120 DEG C. A solution of phosphoric acid in ethanol was then forced into the mixture, the temperature was maintained for 20 minutes and the mixture extruded into aqueous ethanol containing ammonia to neutralize the catalyst. The solution was filtered and poured into aqueous alkali to precipitate N-ethoxymethyl polyhexamethylene adipamide which had suffered relatively little degradation. Other examples are given, using methanol or isobutanol in place of the ethanol. The products may be used for wrapping, for coating fabric for leather substitutes, as adhesives as fibres, for moulding or as interlayers for safety glass. Specifications 461,236 and 535,934 and U.S.A. Specifications 2,071,250, 2,130,948, 2,321,890 and 2,321,891 are referred to.
|
