新型有机电荷传输材料的合成及在OPC中的应用

【作者】 于建香；

【导师】 蒲嘉陵； 王文广；

【作者基本信息】 北京印刷学院 ， 材料物理与化学， 2002， 硕士

【摘要】 无论是用于有机光导体（OPC），还是用于电致发光（EL），一种优秀的电荷传输材料应具备以下特点: （1）电荷传输速度快；（2）与电荷产生材料匹配性好；（3）注入效率高；（4）与树脂的相容性良好；（5）电荷迁移率对电场依赖性小。电荷传输分子均匀溶解/分散于聚合物所形成的体系，即MDP体系（Molecule-Doped Polymer）是比较理想且实用的体系.有机空穴传输材料的种类和数量目前都有非常成熟的研究和应用，但是电子传输材料由于种种原因发展比较缓慢，制约着OPC 、EL等技术的进一步发展，同时传输材料的MDP体系本身存在着一系列的矛盾需要解决，例如 ，提高电荷传输速度就要求实现电荷传输分子的高浓度搀杂，同时，树脂的比例减少，影响了成膜性能，机械强度等。电子传输材料由于其自身的共轭对称性和分子之间很强的相互作用，与高分子的相容性一般较差，难以进行高浓度的搀杂，例如TNF只有在Vylon200（一种树脂）中才能够达到40%，而在其它高分子成膜树脂中的溶解度都非常低，一般不超过20%本课题针对MDP体系以上的矛盾，根据电荷传输分子设计的基本要求，设计并合成了一系列的环状化合物及其它不对称结构的化合物，在母体化合物上连接电荷传输官能团，传输官能团通过化学键的作用实现局部传输基团的高浓度堆集，有可能形成一种局部甚至一定范围内排列有序的“聚集态”结构，提高电荷传输性能。我们采用的母体之一是具有穴状结构的杯芳烃[4]的衍生物，在一个母体上可以形成四个连接传输基团的位置，可以近距离组合传输基团。我们根据这种思路合成了带有环状结构的腙或咔唑，三苯胺的衍生物如HTM1～HTM10（图A所示）带有环状结构的TNF和联苯醌的衍生物如ETM1～ETM4等（图B）。环状结构的衍生物是由合成对叔丁基杯[4]芳烃开始，杯芳烃的羟基以及对位可以比较容易的进行化学转化，生成对位是甲酰基或氨基的产物，杯子下端的羟基经过改造，变成醚基和乙酰基等。活泼的醛和胺与苯肼/二苯肼以及TNF的羰基发生缩合反应，生成所设计的产物。另外还合成了非环状结构的腙以及TNF的衍生物，非环状结构的腙和TNF的衍生物的反应在非常温和的条件下经过缩合反应容易生成。又根据相关的文献报道，由3，3’，5，5’-四叔丁基联苯醌经过了还原，脱叔丁基，氧化等各步反应，成功的合成了3，3’，5-三叔丁基联苯醌（图C中的ETM6化合物）。我们也对3，5-二甲基-3’，5’-二叔丁基联苯醌（图C 中ETM7所示）和环状结构的醌（见图B所示）的合成进行了探讨和尝试，只有完全对称的联苯醌（ETM7）的合成是发生的。ETM2， ETM3和ETM4的合成反应都没有完成，原因可能是直接的氧化偶合方法和格式试剂与卤代物的偶合反应不适合我们所设计的目标化合物。在实验的过程中我们一直没有用缩合的方法得到HTM9，10所示环状结构的化合物，即环状结构母体与咔唑醛和三苯胺基醛的缩合物，但是相对于环状结构的简单化合物的合成却非常简单和成功，而且具有很高的收率。这可能是因为环状结构化合物的位阻或者环状结构本身的特殊性而导致反应难以发生。<WP=4>图A 环化HTM 图中HTM1～HTM2为环化结构的醛与苯肼缩合的产物，HTM3～HTM6为环化结构的醛与二苯肼缩合的产物，HTM9为环化结构的胺与咔唑基醛缩合的产物，HTM10为环化结构的胺与三苯胺基醛缩合的产物。<WP=5>所有合成的化合物经过了TLC、IR、UV、NMR 等测试，基本确定了它们的结构，用DSC测试系统测试了3，3’，5-三叔丁基联苯醌，3，3’，5，5’-四叔丁基联苯醌以及TNF与树脂的相容性。结果表明新型的不对称联苯醌与树脂的相容性很好，可以与PC，PVB，Vlon200以超过50%的浓度搀杂。对所合成的传输材料（HTM3，5，8和ETM1，TNF的衍生物2）与感光范围在780-830nm的H2Pc配合，制作了双层结构功能分离型OPC和单层结构（三组分和双组分）OPC的器件，利用本实验室开发的EMS’93静电照相测试系统测试了所制备器件的静电照相性能。测试结果证明， 环状结构的孔穴传输材料（HTM1，2，3，5）由于与树脂的相容性较低，共轭体系不完全，或者与H2Pc的能级匹配性不好，由它们制作的器件的静电照相性能不好，ETM1和TNF的衍生物2制作的单层三组分的OPC器件的静电照相性能优于TNF的性能，ETM6制作的单层三组分器件的性能也与TNF不相上下，而且与DEH不形成CTC的复合物。表现出良好的电子传输性和静电照相性能。更多还原

【Abstract】 Being used in OPC or in EL, excellent charge transport materials must have these properties：(1) Faster in charge transporting; (2) Suitable for charge generate materials; (3) Effective in injecting; (4) Good solubility in matrix; (5) Independent on electric field. Charge transport molecule equably dispersed or dissolved in polymer to form a MDP system, which is ideal and applied. Organic hole transport materials are well applied in many systems. While electron transport materials are so slow to develop that restrict the progress of OPC and EL technology. At the same time, the system of MDP itself exists a series of conflict to solve, for example, to improve the charge transport efficiency must request that organic molecule have high solubility in matrix, but at the same time, more organic molecule in polymer will reduce proportion of resin and finally affect the performance of polymer film and the mechanical properties of OPC .Not all electron transport materials perform high solubility in polymer for their structure characteristic. For instance, TNF is able to reach 40% weight ratio in Vylon200, but only 20% in other polymer. We have designed a new molecule model and synthesized a series of derivatives of ring compounds according to the essential requirement of charge transport molecule. This new molecule model is based on calix (4) arene which is a ring macromolecule containing four same units of phenol connected by methylene bridge . The calix (4) arene is modified by a series of chemical reactions to form a new aldehyde and amino derivative , and finally the desired compounds HTM1～HTM6 and the derivative 1 of TNF are acquired while the aldehyde or amino is condensed with phenyl hydrazine and N,N-diphenyl hydrazine or TNF . We also gained hydrazone which has non-ring structure and the derivative 2 of TNF . Because of being fixed on ring molecule , the functional groups are in order in short distance. The new molecule model possibily give a way to solve the question of about ETM .3,3’,5- tri(tert-butyl) diquinone is modified by a series of chemical reactions to <WP=7>form a new compound 3,3’,5- tri(tert-butyl) diquinone, we also discuss the way how to synthesis the compound 3,5-dimethyl-3’,5’-di (tert-butyl) diquinone and ring diquinone , and finally find that direct oxidation and Grinand coupling method is not fit for our aim compound .All compounds have been tested by TLC、IR、UV、NMR. Their structures had basically been confirmed. The solubility of 3,3’,5- tri(tert-butyl) diquinone and TNF in polymer solution were tested by DSC testing system .The results show that 3,3’,5- tri(tert-butyl) diquinone have good performance in polymer PC, PVB and Vylon200 which can dissolve in polymer over 50%, and finally we made three kinds of receptors ,the first is single layered receptor which has two contains , the second is also single layered receptor but has three contains ,the last is two layered photoreceptor which have two contains .All photoreceptors must have charge generate material , i.e.,H2Pc we used which has most absorbing in 780～830 nm ,and charge transport materials including hole /electron transport materials, the compounds we have synthesized were CTM component ,their xerographic performance was tested by EMS’93 . They did not behave good performance in xerography resulting from badly solubility in polymer, or little conjugate in structure ,or bad consistent with CGM in ion energy . Another compounds TNF derivatives1 and TNF derivatives 2 are better in xerographic performance than TNF; 3,3’,5- tri(tert-butyl) diquinone has approximately the same performance as TNF in the same content . Further more, it doesn’t also form CTC complex with DEH .更多还原