含红外染料纳米聚合物微粒的制备及其热敏成像性能的研究

Study on Preparation and Thermal Imaging Performance of Polymer Nanoparticles Containing Infrared Absorbing Dye

随着制版技术的发展以及人们环保意识的增强,作为印刷生产中的重要材料,免化学处理的热敏CTP版材正在被越来越多的使用。本研究以热塑性纳米聚合物微粒、水溶性高分子树脂、红外染料以及相应助剂为原料,以十二烷基硫酸钠和十六醇为表面活性剂,通过细乳液聚合技术制备了含红外染料的聚合物纳米微粒;并与聚乙烯醇水性树脂混合后得到了热敏成像涂层。通过紫外分光光度计、Zeta电位仪、凝胶渗透色谱仪、扫描电子显微镜等来表征样品的性能。结果发现,红外染料的浓度对乳液粒径、粒径分布以及聚合分子量分布有一定的影响。该体系在830nm红外激光照射下,曝光部分可以发生热致亲和性变化,变为不溶于水的聚合物,而未曝光部分仍然可以用水洗去,这样利用水显影即可得到清晰的图像。该体系有望用于开发免化学处理热敏CTP印刷版材。

With the development of making plate technology and emphasis on environmental protection,chemical-free-processing CTP plate has been becoming a research hotspot in printing industry.In this study,polymer particles contain near-infrared dye(absorption maximum at about 830 nm,IR-830) were prepared through miniemulsion polymerization technology with nanometer polymer particles,water soluble polymer resin,IR-830 dye and other assistants as raw,sodium dodecyl sulfate and hexadecanol as emulsifier.Polyvinyl alcohol was used as water soluble polymer binder resin for the production of latex coatings.Using the above prepared materials,a thermography coating was prepared.Structure and properties of the sample were characterized by Ultraviolet Spectrophotometer,Zeta Potentiostat,Gel Permeation Chromatographer,Scanning Electron Microscope and so on.The result showed that different concentrations of IR- 830 dye polymer effect molecular weight distributions of polymer,particle size and distributions of latex particles.Under computer-controlled laser exposure,the IR dye-containing polymer particles absorb IR laser energy and produce high temperature,causing great changes of the imaged areas.As a result,the imaged areas could not be removed by water,whereas the polymer particles of the non-imaged areas remain unchanged,and still could be easily removed by water cleaning.After developing with water,negative graphic was obtained.The research result is able to be used in developing chemical-free-processing CTP plates.