PROBLEM TO BE SOLVED: To provide a compound to be a diamine crosslinking agent which can create an acidic polysaccharide crosslinked body for medical material which satisfies all of safety, easy preparation, efficient physical properties alteration and disintegration properties.SOLUTION: The present invention provides a diamine compound of formula (I) having primary amino groups at both terminals and an ester bond in the molecule [Ris H, a -CONRRgroup, a -COORgroup, a substituted/unsubstituted alkyl group, a substituted/unsubstituted alkenyl group or a substituted/unsubstituted alkynyl group； Ris a -CONRRgroup or a -COORgroup； R-Rindependently represent H or an alkyl group substituted/unsubstituted with a phenyl group； Ris H or a methyl group].SELECTED DRAWING: None【課題】安全性・調製の簡便さ・物理的性質変換の効率・分解消失性のすべてを兼ね備えた医用材料用途の酸性多糖架橋体を創出可能なジアミン架橋剤となる化合物の提供。【解決手段】両端が一級アミノ基であり、分子内にエステル結合を有する式（Ｉ）で表されるジアミン化合物。[Ｒ１は、Ｈ、－ＣＯＮＲ３Ｒ４基、－ＣＯＯＲ５基、置換/無置換のアルキル基、置換/無置換のアルケニル基又は置換/無置換のアルキニル基；Ｒ２’は、－ＣＯＮＲ３Ｒ４基又は－ＣＯＯＲ５基；Ｒ３～Ｒ６はそれぞれ独立に、Ｈ又はフェニル基で置換/無置換のアルキル基；Ｒ８’は、Ｈ又はメチル基]【選択図】なし
