【作者】 史瑶；

【导师】 李金培； 刘春艳；

【作者基本信息】 中国科学院研究生院（理化技术研究所） ， 物理化学， 2008， 博士

【摘要】 虽然光敏热显影材料(Photothermographic imaging materials, PTG)在医用胶片领域中得到广泛地应用和发展,但是PTG材料仍存在着诸如感光性能低等问题。为了解决以有机长链脂肪羧酸银为银源的光敏热显影材料(PTG)感光性能低的问题,我们选用另一类银盐,苯并三氮唑银,作为银源,构建成以聚乙烯醇(PVA)为粘合剂的亲水性PTG材料体系,从调色/显影促进剂和光敏元等方面对苯并三氮唑银体系进行了研究,主要研究内容和结果如下:1.调色剂邻苯二甲酸(H2PA)对苯并三氮唑银(AgBTA)体系的影响。邻苯二甲酸(H2PA)具有促进AgBTA体系显影的作用,其阳离子(H+)降低了体系的pH值,同时也降低了还原剂的显影活性和H2PA与银离子的络合能力;其阴离子(PA2-)与苯并三氮唑银在热显影过程中生成中间体,起到传输银离子的作用。2.调色剂酞嗪(PHZ)对苯并三氮唑银体系的影响作用。PHZ引入AgBTA体系中可以起到促进AgBTA光敏热显影材料显影的作用,并且该作用随着其用量的增加而增大。在AgBTA体系中协同使用PHZ和H2PA的显影促进作用要好于单独使用PHZ的作用。在使用PHZ/H2PA的AgBTA体系中,PHZ的促进作用随AgBTA乳液体系的pH值增加而增强。分析表明,PHZ与AgBTA生成银复合物而发挥显影促进作用,生成的银复合物是无定型的晶体并且对AgBTA颗粒的热性能没有影响。3.新调色剂烟酸对苯并三氮唑银体系的作用。在AgBTA体系中,烟酸可以作为新的调色剂促进显影提高显影密度,并且烟酸的显影促进作用随体系pH值的增加而增强。通过实验寻找到烟酸的最佳用量和条件:烟酸用量为10%,体系的pH值为8。分析测试结果表明烟酸与AgBTA生成银络合物促进显影。4.显影促进剂硫脲类化合物在苯并三氮唑银体系中的作用研究。硫脲化合物加入AgBTA体系中均可以起到增加显影密度的作用,其中带有推电子取代基的硫脲更适合作为AgBTA的显影促进剂。防灰雾剂四氯邻苯二甲酸(H2PACl4)和四氯邻苯二甲酸酐(TCPA)都可以抑制四甲基硫脲加入AgBTA体系后热显影产生的灰雾。5.光敏元AgX对苯并三氮唑银体系的影响研究。苯并三氮唑银光敏热显影体系中,卤化剂(NH4Br)与苯并三氮唑银乳液共同球磨可以置换生成AgBr光敏元。对于阳离子相同的卤化剂而言,提高体系感光性能的顺序为:KI>KBr>KCl。异位加入AgBr乳剂颗粒的苯并三氮唑银体系的感光性能要好于NH4Br原位置换AgBr体系的性能;乳剂颗粒形状不同对提高体系的感光性能影响不同,其中T-颗粒乳剂>八面体乳剂>立方体乳剂。更多还原

【Abstract】 In recent year, significant advances were made in technology of photothermographic imaging materials (PTG), and wide application was realized in medical films fields. However, there were still some problems need to be improved, such as low sensitivity of PTG materials and so on. In order to solve the problem of low sensitivity of PTG materials, another kind of silver salt differed from long chain silver carboxylates, silver benzotriazoles, was used as silver sources to construct the hydrophilic PTG materials with polyvinyl alcohol (PVA) as binder. We studied the influence factors, such as toners/development promoters and light capturing photocatalysts, in the photothermographic imaging materials based on silver benzotriazole as silver sources. The main results were summarized as follows:1. Effects of phthalic acid(H2PA) as toners on silver benzotriazole photothermographic imaging materials. Phthalic acid (H2PA) promoted the development of photothermographic imaging system based on silver benzotriazole as silver source. The results indicated that the positive ion (H+) of H2PA decreased the value of pH in the system, imaging activity of developer and the capability of H2PA combined with silver ions; the negative ion (PA2-) of H2PA created the intermediate with silver benzotriazole and the intermediate carried silver ions during the thermo-imaging process.2. Effects of phthalazine(PHZ) as toners on silver benzotriazole photothermographic systems. The results indicated that the development of silver benzotriazole materials was promoted by the introduction of phthalazine (PHZ), and the promotion was strengthened with increasing the amounts of PHZ. The cooperative promotion of PHZ and H2PA was better than that of single PHZ. The promotion of PHZ increased with increasing the pH of the silver benzotriazole emulsion constructed from phthalazine/phthalic acid (PHZ/H2PA) toner system. The analysis data implied that a silver complex, which was supposed to be easy to transmit silver ions to development center, produced by PHZ and silver benzotriazole. The above silver complex was non-fixed structure crystal and did not affect the thermal performance of silver benzotriazole.3. Influences of nicotinic acid as a new toner on silver benzotriazole systems. The results indicated that the development of silver benzotriazole materials promoted by the introduction of nicotinic acid as a new toner. The promotion of nicotinic acid increased with increasing the pH of the silver benzotriazole emulsion. The results showed that the best promotion of nicotinic acid could be obtained in the case of the mol ratio of nicotinic acid to silver benzotriazole 0.1 and value of pH in emulsion about eight. The analysis data implied that the silver complex produced by nicotinic acid and silver benzotriazole. 4. Effects of thioureas compounds as auxiliary ligands improving the solubility of silver benzotriazole. The results indicated that the thioureas that added into system all promoted the silver benzotriazole development and the promotion increased with the amount of thioureas. The thiourea substituted by electron donor groups as development promoters was more favorable. Tetrachlorophthalic acid(H2PACl4) and tetrachlorophthalic anhydride(TCPA) as antifoggants all decreased the minimum or fog density of silver benzotriazole system including tetramethylthiourea.5. Effects of AgX as photocatalysts on silver benzotriazole photothermographic imaging system. The results revealed that the in situ AgBr grains were formed in condition that NH4Br ball-milled with silver benzotriazole. According to KX series, Sensitivity of PTG films were improved in the descending order: KI>KBr>KCl. Ex suit formed AgX emulsion grains introduced into PTG construction was more favorable for improving the sensitivity of PTG films than in suit made AgX particles introduced by halogenating agent NH4Br. The improvement depended on emulsion grains sharps and sizes, and the influence improved in that descending order: tabular grain > octahedral grain > cubic grain.更多还原