| 摘要 |
Polyamide resins of softening pt. of 100-180 degrees C, consisting of condensation prods. of (a) a polymeric fatty acid with a content of dimeric fatty acid of 80-100 wt. % and (b) =10 wt. % (w.r.t. (a)) of a dicarboxylic acid of formula HOOCR-COOH, where R denotes an alkyl residue of 4 to 10 C, a cycloaliphatic, aromatic or araliphatic residue, (c) 0.8 to 0.98 eq. ethylene diamine, and (d) 0.02 to 0.2 eq. of an etherdiamine of the formula H2N-(CH2)n-O-(R-O)x-(CH2)nNH2 (where R is an alkyl grp. of chain length of 1 to 44 C, which opt. may carry alkyl substituents of 1 to 4 C; n = 3 to 5; and x = 0, 1, 2, or 3), are used as stiffening material for shoe caps. The shoe caps exhibit greater stiffness than previously used materials and the prods. exhibit a better cold flexibility and excellent adhesion to synthetic shoe material. |
