【作者】 范明明；

【导师】 邹竞； 王虹；

【作者基本信息】 天津大学 ， 化学工艺， 2008， 博士

【摘要】 光敏热显成像材料(Photothermographic materials,简称PTG材料)是近年来国际感光界的研究热点之一。PTG材料具有成像质量优异,影像保存稳定性高,干式加工便捷无污染等优点,因此尽管传统的卤化银胶片市场正在逐步萎缩,而具有环境友好特点的PTG材料市场仍有着良好的发展前景。当前,国际感光界的学者正在大力开展对PTG材料成像机理方面的研究。其中美国学者Whitcomb和日本学者Maekawa对于PTG材料热显影过程中银离子的迁移及还原过程进行了深入的分析研究,并提出了不同的见解。本论文以邻苯二甲酸(PA)与酞嗪(PHZ)为起始原料,采用液相沉淀法合成了PTG材料热显成像过程中可能存在的含银中间体邻苯二甲酸二银(Ag2PA)与[Ag2PHZ2PA·H2O]配合物,通过元素分析、ICP-AES分析对Ag2PA与[Ag2PHZ2PA·H2O]配合物的元素组成进行了确定,采用XRD、FTIR、TG与DSC等方法对Ag2PA与[Ag2PHZ2PA·H2O]进行了表征,确定了其分子结构。通过对PTG材料热显影过程中银离子迁移过程的分析表明,调色剂PA与PHZ在PTG材料热显影过程中起着改变反应历程,降低反应活化能的作用,Maekawa等提出的银离子迁移路线具有一定的合理性。采用X射线衍射K值分析法,在100~123℃PTG材料热显影温度范围内,研究了山嵛酸银(AgBeh)与PA的固相反应过程。结果表明,AgBeh与PA的固相反应为固态扩散控制过程。在一定的反应时间内,Jander方程能够较好的描述AgBeh与PA的固相反应动力学,反应的表观活化能为84.5 kJ·mol-1,表观频率因子为7.06×107 min-1。AgBeh与PA样品以较小的颗粒度分散于PTG体系中,有利于提高PTG材料的成像速度。通过XRD及FTIR等方法对Ag2PA与PHZ之间的反应进行研究,结果表明Ag2PA与PHZ可以通过固液相反应发生作用,反应物的扩散过程为Ag2PA与PHZ之间反应的控制步骤。测定了调色剂PA、PHZ与6-异丙基酞嗪在粘合剂PVA中的扩散系数。实验表明,温度越高,调色剂的扩散系数越大。在相同的条件下,PHZ与6-异丙基酞嗪的扩散系数均远大于PA的扩散系数。随着粘合剂浓度的增大,PA、PHZ与6-异丙基酞嗪的扩散系数均有所降低,这种降低的趋势在不同的温度条件下均有体现。综合分析认为,对于PA—PHZ的调色剂组合体系,决定银离子迁移速率的主要因素为调色剂PA在粘合剂涂层中的扩散行为,适当增加PTG材料的热显影温度、调整涂层结构与配方以缩短调色剂PA在涂层中的有效扩散距离以及降低PTG材料涂层中粘合剂的浓度均有利于提高PTG材料的显影速度,即提高PTG材料的热显影效率;对于PA—6-异丙基酞嗪的调色剂组合体系,在实际的PTG材料热显成像条件下,调色剂6-异丙基酞嗪的扩散行为会对银离子的迁移速率起到一定的限制作用,而这种限制作用有利于获得色调更佳的银影像。测定了调色剂PA、6-异丙基酞嗪在苯丙乳液粘合剂中的扩散系数并确定了扩散活化能。实验数据显示,PA、6-异丙基酞嗪在苯丙乳液粘合剂中的扩散系数均略大于其在同浓度PVA粘合剂中的扩散系数。更多还原

【Abstract】 As one of those frontier subjects in the field of photographic science, photothermographic materials (PTG materials) have attracted many attentions for their various advantages, such as excellent imaging quality, steady image preservation, convenient operation and pollution-free dry technology. Although traditional silver halide film market has been shrinking severely in recent years, PTG materials have showed its bright future. Since understandings about the detail of the relevant imaging process would be the key for deeper researches, scholars in this field have made great efforts in order to reveal the concerning mechanism; among them, Whitcomb and Maekawa have the very important silver ion transfer and reduction process thoroughly investigated and analyzed, but raised quite different proposals.In current study, using phthalic acid (PA) and phthalazine (PHZ) as the starting materials, di-silver phthalate (Ag2PA) and complex [Ag2PHZ2PA·H2O], which were supposed to be the silver-intermediates in the development process, were prepared using liquid deposition approach; their compositions and structures were carefully characterized through methods of ICP-AES, elemental analysis, XRD, FTIR, TG and DSC. The analysis of silver ion transfer in development process for PTG materials showed that the toners PA and PHZ could have the reaction course changed and the activation energy reduced, and the silver ion transfer course proposed by Maekawa seemed to be reliable in some extent.Using X-ray powder diffraction (K value) method, the solid state reaction between silver behenate (AgBeh) and PA was studied within the developing temperature of PTG materials ranged from 100℃to 123℃. The obtained data showed that this reaction was actually diffusion-controlled, and Jander equation could properly describe this reaction in a certain reaction time course. The apparent activation energy and apparent frequency factor of the solid state reaction were 84.5 kJ·mol-1 and 7.06×107 min-1, respectively. Diminishing the granularity of AgBeh and PA could speed up the progress of development. XRD and FTIR results proved that the reaction between Ag2PA and PHZ was controlled by the diffusion of the reactants.The diffusion behavior of PA, PHZ and 6-isopropyl phthalazine in binder PVA were measured, and the diffusion coefficients for PHZ and 6-isopropyl phthalazine were found to be larger than that of PA. It could be seen that the values of the above mentioned diffusion coefficients would be increased if raising the diffusion temperature. For each of the following systems, such as PA—PVA, PHZ—PVA and 6-isopropyl phthalazine—PVA, the values of the diffusion coefficients would become smaller with the increase of the binder concentration under different temperatures. For PA—PHZ co-toner system, the main factor of controlling the silver ion transfer velocity was the diffusion behavior of PA in the binder coat. Several technical improvements, such as increasing the development temperature, shortening the diffusion distance of PA in the binder coat by adjusting the coat structure and ingredients, decreasing the binder concentration, were all advantageous for enhancing the development velocity. For PA—6-isopropyl phthalazine co-toner system, the diffusion behavior of 6-isopropyl phthalazine in the binder coat would limit the silver ion transfer velocity, therefore be propitious to obtain a better silver image.The diffusion coefficients of toners PA and 6-isopropyl phthalazine in the binder styrene-butyl acrylate latex were also measured, and the diffusion activation energies of PA and 6-isopropyl phthalazine were determined. The experimental data showed that the diffusion coefficients of PA and 6-isopropyl phthalazine in styrene-butyl acrylate latex were greater than those of PA and 6-isopropyl phthalazine in PVA under the same binder concentration.更多还原