聚氨酯型染料的合成及其在皮革加工过程中的着色理论研究

Pigments used in leather finishing process exists the problem of poor smooth feeling, resistance to wet rubbing, fastness to solvent, etc. Polyurethane dyes with the characteristics of high strength, easy film forming, resistance to solvent, resistance to transference, stability to heat and manufacturability and low toxicity, etc. In this project a new kind of polymeric dyes is prepared through the polycondensation reaction by yellowness resistance isocynate polyester containing hydroxyl group, reactive dyes, chain extension agent. The effluence of molecular weight and terminal group on the color fastness will be discussed; The ration of soft and hard segment of the polyurethane is adjusted to get the appropriate glass transition temperature, in order to ensure that the polyurethane polymeric dyes with the perfect moisture permeability and steam performance. The color fastness of product applied in leather coating will be studied, such as resistance to transference, resistance to solvent, resistance to dry and wet rubbing, fastness to heat and fastness to sunlight. The products are characterized by IR and DTA. The polyurethane dyes are applied in the leather coating instead of pigment and dyes. The dyeing theory for series of polyurethane dyes in leather coating is studied by using UV-VIS and IR.

皮革加工过程中所用颜料存在平滑性和细腻感差、成革不耐湿擦、耐溶剂性不佳等缺点。聚氨酯染料具有高分子的高强度、易成膜性、耐溶剂性、耐迁移性、耐热性和可加工性及安全低毒等特性。本项目由耐黄变异氰酸酯与含羟基聚合物、含活性基团染料、扩链剂等通过缩聚反应得到产品，讨论分子量大小和端基基团对聚氨酯高分子染料色牢度的影响；通过对聚氨酯软段和硬段比例的调整使得聚氨酯高分子染料具有合适的玻璃化温度，以保证使用聚氨酯染料涂层的良好透湿气性能。研究产品在涂层应用后的色牢度，包括耐迁移性、耐溶剂性、耐干湿擦、耐热、耐日晒等性能。对目标产物通过IR、DTA等现代分析手段进行表征。将合成的聚氨酯高分子染料在皮革涂层中代替颜料膏和染料水使用，采用紫外-可见分光光度计、红外光谱等测试方法对系列聚氨酯高分子染料在皮革涂层中的着色理论进行研究。

本课题研究中，首先以2，4-甲苯二异氰酸酯（TDI）和聚丙二醇1000（PPG-1000）为原料合成聚氨酯预聚体，用2,2-二羟甲基丙酸（DMPA）扩链制备端异氰酸酯基团的聚氨酯，并用带有羟基基团的酸性染料（酸性红B、酸性嫩黄G、弱酸性黑BG）对其进行封端改性处理，获得相应的聚氨酯型大分子染料。调整合成参数制得了分别应用于制革染色工艺的聚氨酯大分子染料和应用于制革涂饰工艺的聚氨酯大分子染料（简称PUⅡ—酸性红B、PUⅡ—酸性嫩黄G、PUⅡ—弱酸性黑BG）。在制备过程中预聚反应最优实验参数为n(-OH)：n(-NCO) =1:3~1:4，加入DMPA扩链和用染料封端并控制体系反应参数总R值为1.1~1.2。.通过红外光谱、激光粒度分析、色牢度分析以及热性能分析测试等手段对产物以及涂膜性能进行表征与研究，结果表明：酸性染料经酰胺键（-CO-NH-）能够连接在聚氨酯链端，并形成水性高分子染料；这种高分子染料分散体系的乳液平均粒径在60~160um，可以稳定存放，满足水相染色要求；涂膜的热力学等性能也符合皮革涂饰的要求。聚氨酯型高分子皮革染料上染实验研究表明:聚氨酯型高分子皮革染料上染皮纤维是,聚氨酯染料以离子键、氢键、分子间作用力与皮纤维产生交联，从而与皮纤维达到更牢固的结合。