印刷制版用N_2等离子体蓝紫光源的实验研究

我国的印刷制版行业目前正处于从传统PS版向计算机直接制版(Computertoplate)技术转变的进程之中,PS版的产销量十分可观,在CTP技术中继续使用传统的PS版对我国印刷包装行业意义重大。实现传统PS版的CTP技术关键在于解决曝光光源问题。本文采用连续直流源空心阴极放电方式产生氮气等离子体蓝紫光源,成功地对一种超感度重氮萘醌系PS版进行曝光,从注入功率、放电气压等方面探讨了氮气等离子光源的最佳工作条件,在工作气压70Pa、放电电压580V、电流1.8A下获得了0.46mW/cm2的蓝紫光输出。气体放电光源还可轻易实现高频大功率脉冲输出,本研究结果表明,新型空心阴极氮气等离子体光源在实现PS版CTP技术方面具有一定的发展前景。     

普通PS版感光特性的研究

计算机直接制版技术(CTP)是当前印刷技术领域研究的热点问题之一,采用传统PS版的计算机直接制版(CTCP)由于继续沿用传统的预涂感光版(PS版),在印刷适性、耐印力、印品分辨率等方面具有明显的优势,同时成本低,市场量大。但人们对PS版感光材料曝光特性的研究相对较少,本文给出了1种超感度重氮盐PS版的最低曝光能量同波长之间的关系,在波长405nm处所需的临界曝光能量仅为10.35m J/cm2。从曝光前后颜色密度值变化、感光材料红外分析方面,对PS版的曝光效果做了详细的测量。     

用于CTCP技术的射频无电极放电氮气等离子体光源研究

本文报道了一种利用射频无极放电激励的氮气等离子体新型光源,成功地对“星光”PS版进行了曝光,光谱分析表明氮气射频放电光源的光谱结构较碘镓灯更适于传统PS版曝光。为此,进一步从射频功率、工作气压等方面探讨了光源的最佳运行参数,得到在230Pa、160W采用两个传输透镜聚焦后获得的光源功率密度是2.23mW/cm2。最后给出了运用此光源对PS版的曝光结果。     

显影对PS版性能的影响

阳图PS版感光层中的感光树脂经曝光发生光分解反应后,感光层可被显影液溶解形成稳定的亲水空白部分;而未曝光的感光层显影后仍留在印版上,具有亲油性而构成图像部分,这样就形成可上机印刷的印版.印版从胶辊上接受油墨而转印到纸张等承印物上,就制成了印刷品.     

胶印PS版与感光胶浅析

胶版印刷在整个印刷领域中占据了主导地位。胶版印刷采用的预制感光版(PS版)已成为胶印的主要版材。目前。我国PS版的年生产能力已达3500万m2,仅从数量上看已经供大于求,但是存在品种少的缺憾。提高PS版质量,增加PS版品种的工作重点之一是改进感光胶质量。本文还简要介绍了计算机直接制版技术(CTP),并指出CTP非银盐版材和热敏版材将是今后CTP版材的发展方向。     

阳图感光胶的树脂匹配

PS版印刷仍会在较长时期内存在,感光胶在PS版的成本构成中所占比例不大,但对PS版的质量却起着至关重要的作用。文章从感光胶的成分出发,概述了感光胶中树脂匹配的重要性及如何匹配树脂,以达到感光胶的最佳应用效果。     

阳图PS版用重氮萘醌系感光组成物研究进展

目前PS版在印刷领域仍占有较重要地位,重氮萘醌系感光组成物自20世纪应用以来,经久不衰。文章主要介绍了PS版用重氮萘醌系感光组成物的研究进展情况,包括重氮类感光化合物,与之配合使用的版基、成膜树脂、酯化体。同时产酸剂、背景染料、溶剂及其它添加剂简单进行了归纳,并研究了重氮萘醌系阳图PS版的配方化学及发展趋势。     

胶印PS版用成膜树脂及酯化树脂的发展

胶印PS版由于生产工艺成熟,价格便宜,制版设备简单,是目前印刷领域使用最为广泛的版材。对胶印版材所用的成膜树脂和阳图感光PS版用酯化树脂的相关文献进行了综述。成膜树脂是胶印PS版中非常重要的组成部分。酯化树脂的作用是将感光基团引入感光组成物。成膜树脂重点介绍了酚醛树脂和烯类树脂,酯化树脂则着重于介绍酚醛树脂和酚树脂。     

影响感光制版曝光的因素

阐述了在建陶产品如印花砖的丝网感光制版中影响模版质量的有关因素。在丝网印刷感光制版的各种因素中，涉及到网版的因素最多，而其中一半的因素与曝光有关。网版质量与曝光时间有着密切的关系，而曝光 时间则受多种因素的影响，其主要有四个方面：网版、丝网、光源和曝光时间、感光胶的湿度。     

一种用于CTCP技术的新型脉冲等离子体光源

继续沿用传统PS版的计算机直接制版技术(CTCP)对于我国的印刷包装行业具有特殊重要的意义。亟待解决的问题是实现光源对PS版的脉冲式曝光。本文报道了一套采用正弦脉冲高频电源激励的新型氮气等离子体光源,首次获得了光源的准脉冲输出,并成功的对一种超感度PS版进行了曝光。光谱分析表明氮气等离子体光源的光谱结构较碘镓灯更适于传统PS版曝光。进一步从电源电压、工作气压等方面探讨了光源的最佳运行参数,随着电源功率的增大和光源结构参数的优化,可望得到更大的光输出功率。本文对实现CTCP技术的脉冲式曝光具有一定的参考价值。     

TiO_2和Ag修饰硅基电极的光电性能研究

采用n型单晶硅经光电化学阳极刻蚀成多孔硅,然后用TiO2和硝酸银溶液修饰多孔硅表面,通过电流-电压关系,时间-电流密度关系等方法研究几种复合多孔硅电极的光电性能,发现用TiO2和金属膜修饰的多孔硅电极光电流敏感,启动电压低,亮暗电流比明显,表现了更好的电极稳定性。     

无皂乳液聚合法合成聚苯乙烯微球应用于准固态电解质染料敏化太阳能电池

制备了一种提高染料敏化太阳能电池短路电流和电池光电转化效率的准固态凝胶电解质,该电解质含有5%高聚物PVDF-HFP和2% TiO₂纳米颗粒。另外,通过乙醇相无皂乳液聚合法合成了大小均一的聚苯乙烯微球,并用于制备染料敏化太阳能电池的多孔光阳极。研究了准固态电解质和液态电解质应用于不同光阳极染料敏化太阳能电池的规律。结果表明,与液态电解质相反,准固态电解更适用于孔洞较多的光阳极,在相同测试条件下,电池的短路电流由12.80 mA·cm^-2提高到13.53 mA·cm^-2,效率比液态提高11.43%,达到6.63%。     

Investigation of Morphology of Porous Silicon Formed on N+ Type Silicon

The properties of porous silicon (PS) are closely connected to its morphology, much investigation has been done in order to correlate the morphological characteristics of PS with the anodisation parameters. In this paper the results of morphological analysis of PS formed on N⁺type substrates of 1 0 0 and 1 1 1 orientation are presented. The dependences of the porosity, thickness of PS, density of pores and of the effective surface on the current density are obtained. Interpretation of these results in terms of diffusion layer and energy levels is given, with special attention given to the low current density case.     

CO_2/PS等静压微孔发泡研究

对CO_2与PS在高压设备中进行等静压处理的微孔发泡进行了研究。结果表明,改变CO_2的压力可以控制发泡的泡孔密度和泡孔大小。增加等静压的压力和PS中CO_2的浓度,可以提高泡孔的密度、减小泡孔的直径。结合CO_2的扩散及释压发泡,获得了CO_2在PS中扩散过程的数据,采用剩余界面法得出了CO_2在PS中的扩散厚度与扩散时间的关系。根据CO_2在PS中解吸附的特征,对泡沫不发泡皮层的厚度控制也进行了研究。     

Synthesis and foaming of water expandable polystyrene-activated carbon (WEPSAC)

In this study, water acts as a co-blowing agent to support carbon dioxide (CO₂) in the extrusion foaming process of polystyrene (PS) to produce foams with very low density for thermal insulation applications. Herein, we report a simple suspension polymerization method to prepare water expandable polystyrene (WEPS) based on a PS/water containing activated carbon (AC) composite. AC pre-saturated with water was introduced into the styrene monomer to form a water-in-oil inverse emulsion without emulsifiers. Via suspension polymerization, water expandable PS/AC (WEPSAC) beads could be subsequently obtained. Low density PS foams (∼0.03 g/cc) were successfully produced in the CO₂ extrusion foaming process using WEPSAC. Because of lower foam density and better IR absorption due to the presence of water containing AC, WEPSAC foams provided a lower thermal conductivity than conventional talc reinforced PS foams.     

Formation of Porous Silicon Filter Structures with Different Properties on Small Areas

Porous silicon (PS) layer systems have a broad range of possible applications. An advantage is the good control of the refractive index and the etch rate of the layers by the applied current density and the time respectively. For micro-optical devices you need patterned PS. For some optical devices it is not sufficient to have only one filter but it is necessary to form filters with different properties on a small area. We applied a method (M. Frank, U.B. Schallenberg, N. Kaiser, and W. Buß, in Conference on Miniaturized Systems with Microoptics and Micromechanics, edited by M.E. Moamedi, L.J. Hornbeck, and K.S.J. Pister (SPIE, San Jose, 1997), SPIE Proceedings Series 3008, p. 265) to PS which fits this goal by the following steps: fabrication of the desired reflectors below each other and partial removal of upper reflectors with reactive ion etching (RIE). The technological aspects of patterning PS after the fabrication are an important topic of this work. Problems are discussed in detail and solutions are given.     

Nanocellular Foams of PS/PMMA Polymer Blends

A nanocellular PS/PMMA polymer blend foam was prepared, where bubble nucleation was localized in the PMMA domains. The blend, which contains dispersed nanoscale PMMA islands, was prepared by polymerizing MMA monomers in a PS matrix to form highly dispersed PMMA domains in the PS matrix by diffusion mixing. The resulting blend was foamed with CO₂ at room temperature. A higher depressurization rate at lower foaming temperature made the bubble diameter smaller and the bubble density larger, and a higher PS composition in the blend resulted in a larger bubble density. A void with 40–50 nm in average diameter and a pore density of 8.5 × 10¹⁴ cm^?3 was obtained as for the finest nanocellular foams.