| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject remoldable polymer with controllable reaction by heat treatment of a low molecular weight thiourea polymer obtained from a cyclic tiourea compound and formaldehyde. SOLUTION: This polymer is a high molecular weight tiourea polymer of formula I or II (R and R1 are each alkyl, cycloalkyl or a substitution product thereof; n, p and q are each an integer) having 20,000-100,000 weight-average mean molecular weight. For instance, the polymer of formula I is obtained by adding formaldehyde to a cyclic tiourea compound of formula II (e.g. 4- methyl-2-imidazolidinethione) and treating at pH 5-10 then at pH 1-4 to obtain a low molecular weight tiourea polymer of formula IV (m is an integer) having 2,000-6,000 weight-average molecular weight and then heat-treating the obtained low molecular weight tiourea at 180-250 deg.C. The polymer is obtained by these easy treatments and usable as various molding materials or the like.
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