| 摘要 |
<p>This invention provides an aliphatic secondary diamine which is N,N'-di-(3,3-dimethyl-2-butyl)-1,6-diaminohexane, and a chain extender which comprises N,N'-di-(3,3-dimethyl-2-butyl)-1,6-diaminohexane and a mixture of 2,4-diethyl-6-methyl-1,3-benzenediamine and 4,6-diethyl-2-methyl-1,3-benzenediamine.</p> |
