共查询到18条相似文献,搜索用时 93 毫秒
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以丁二酸、苹果酸(w=2.00%)为活化剂,乙二醇、异丙醇和乙二醇丁醚(w=3.00%)为助溶剂,聚乙二醇-6000(w=0.25%)为成膜剂,咪唑(IM)、苯并咪唑(BIA)和苯并三氮唑(BTA)分别为缓蚀剂,配制系列水基免清洗助焊剂。用静态失重法、电化学阻抗谱法和扫描电子显微镜等方法研究了三种缓蚀剂对金属铜的缓蚀作用。结果表明:随三种缓蚀剂含量的增加,缓蚀率均表现出先提高后降低的趋势。其中BTA的添加量为0.08%时,缓蚀率达88.78%,金属膜电阻Rf达1.25×106·cm2,缓蚀效果最佳。研究还表明:缓蚀剂总量为0.08%时,BIA和BTA复配(0.04%BIA+0.04%BTA),缓蚀率达94.25%,Rf达2.26×106·cm2,显示出明显的缓蚀协同效应。助焊剂铺展实验也表明,复配缓蚀剂的最佳添加量为0.04%BIA和0.04%BTA。 相似文献
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通过实验优选了环保型水性免清洗助焊剂所用的活化剂、成膜剂和表面活性剂等组分。采用交流阻抗法确定了缓蚀剂苯并三氮唑(BTA)的最佳配比,探究了体系中各组分对助焊剂缓蚀性能的影响。结果表明,酸–胺复配可以降低助焊剂的腐蚀性,而缓蚀剂BTA能显著提高助焊剂体系的缓蚀性能。当苹果酸和己二酸以1∶5的物质的量之比与三乙醇胺复配,n复配酸∶n三乙醇胺=11∶1,且酸–胺复合液的质量分数为3.15%、表面活性剂聚乙二醇2000的质量分数为0.2%、缓蚀剂BTA的质量分数为0.05%,助溶剂异丙醇和乙二醇丁醚的质量分数均为1.5%,成膜剂聚乙烯醇的质量分数为0.2%时,所制备的助焊剂体系的缓蚀性能最佳,膜电阻最大,为6.2×105Ω·cm2。该助焊剂体系对基底金属铜板的腐蚀性较弱。 相似文献
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以丁二酸、苹果酸(w= 2.00%)为活化剂,乙二醇、异丙醇和乙二醇丁醚(w= 3.00%)为助溶剂,聚乙二醇-6000(w= 0.25%)为成膜剂,咪唑(IM)、苯并咪唑(BIA)和苯并三氮唑(BTA)分别为缓蚀剂,配制系列水基免清洗助焊剂。用静态失重法、电化学阻抗谱法和扫描电子显微镜等方法研究了三种缓蚀剂对金属铜的缓蚀作用。结果表明:随三种缓蚀剂含量的增加,缓蚀率均表现出先提高后降低的趋势。其中BTA的添加量为0.08%时,缓蚀率达 88.78%,金属膜电阻Rf 达1.25×106 Ω·cm2,缓蚀效果最佳。研究还表明:缓蚀剂总量为0.08%时,BIA和BTA复配(0.04%BIA + 0.04% BTA),缓蚀率达94.25%,Rf 达2.26×106 Ω·cm2,显示出明显的缓蚀协同效应。助焊剂铺展实验也表明,复配缓蚀剂的最佳添加量为0.04% BIA和0.04% BTA。 相似文献
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免清洗助焊剂在电子类产品中的应用 总被引:10,自引:0,他引:10
本文综述了适用于电子类产品的两种类型的免清洗助焊剂 ,即低松香型和无松香型免清洗助焊剂 ,分别介绍了两种免清洗助焊剂在工业上的原料配比情况与相关生产工艺要求 ,并给出了免清洗助焊剂的质量指标和相关检测方法 ,在此基础上分析了其市场信息 ,得出导致目前市场竞争激烈的原因。 相似文献
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张克贤 《精细与专用化学品》2010,18(7):56-60
高效环保型海面溢油分散剂可以有效地消除海洋溢油污染,本课题研制的高效环保型溢油分散剂使用易分解、低毒性的酯型表面活性剂作乳化分散剂,溶剂选择无毒的油酸酯。既满足了乳化分散性,又确保对环境无污染。所制备的高效环保型海面溢油分散剂的技术和性能指标达到国家标准GB 18188.1-2000的要求。 相似文献
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The science of understanding how fires burn and how heat smoke and gases are generated and affect people has progressed substantially in the last half century. The principles of facility design for life safety in fires have reached a degree of maturity. Standards and code provisions for fire detection, suppression and control have become the norm. Real‐scale (or nearly real‐scale) test methods for the flammability of furnishings and interior finish have been established. In addition, some tests have been developed that measure the results of the burning of a small sample from the finished product. Yet, while there have been numerous small‐scale apparatuses developed for assessing the generation of heat, toxic gases, and visible or corrosive smoke, these facets of life and property safety have not found widespread inclusion in building and fire codes. There has been an invigorated effort in ISO TC92 SC3, Fire Threat to People and the Environment, to develop a coherent and comprehensive set of fire safety standards and guidance documents for life safety. Smaller efforts are ongoing within some national and regional standards bodies. In November 2008, experts in this field gathered at The Royal Society in London to hear papers that captured the state of the art and to discuss where we might go from here. This paper summarizes the papers and the discussion from that meeting. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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正向渗透(FO)是一种以溶液自身渗透压作为推动力的膜分离技术。温度对溶液、膜的性质以及溶液与膜之间的相互作用有很大影响,进而影响FO的水通量。利用数值模拟与试验研究了温度对FO性能的影响。结果表明,当膜两侧等温时,FO水通量随着温度的升高而增大;当膜两侧不等温时,原液(FS)一侧温度的影响比提取液(DS)一侧更大,主要是因为温度升高降低了溶液黏度,强化了过膜扩散过程,而温度对DS渗透压的影响不明显。在不同温度条件下,FO水通量和热通量随流量的增大而增大,主要是由于流速的增大压缩膜表面的流体边界层,强化了传质和传热过程。 相似文献
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流化床开车、停车及反应控制过程中,对流化床的流量进行调节的不当操作可能致使局部热点的出现,使操作状态恶化,故充分认识流化床的非稳态流化特性具有重要意义。选用直径为0.45 mm的玻璃珠,在厚15 mm、宽400 mm、高1200 mm的二维流化床中进行液固流态化实验,研究了流量变化对颗粒浓度的影响。实验发现,当流量下降时,流化床中形成了浓-稀相突跃界面,且界面前方有过渡段存在;而当流量上升时,流化床中形成的是由浓到稀的过渡段,变化过程中其浓度波动要远大于流量下降时,且需要更长的时间来达到稳定。以相同时间完成流量下降时,流量变化量较小,则流化床各段的平均颗粒浓度变化速度较慢,同时不利于浓-稀相界面的形成。流量下降幅度相等、流量变化时间延长,则使流化床中的颗粒浓度变化速度呈现先慢后快的特点,同时流量变化较慢,则浓-稀相突跃界面不易形成。 相似文献
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In order to study the effect of heat flux and inlet temperature on the fouling characteristics of nanoparticles, and to further reveal the fouling mechanism for insights into proper operating conditions, γ-Al_2O_3/water suspensions were chosen as the subject of this research. The particulate fouling characteristics of γ-Al_2O_3/water suspensions on the surface of stainless steel have been experimentally studied by varying the heat flux and the inlet temperature under single-phase flow and subcooled-flow boiling conditions. The results show that in the condition of single-phase flow, the asymptotic value of fouling resistance decreases with increasing of heat flux and inlet temperature. The asymptotic value of fouling resistance under single-phase flow is much higher than for the subcooled-flow boiling condition. The effect of heat flux on the fouling resistance under the two flow states has an inverse relationship, and there exists a minimum value of fouling resistance between these two states. For subcooled-flow boiling, the asymptotic value of fouling resistance increases with increasing heat flux, whereas the effect on fouling resistance by the inlet temperature is negligible. 相似文献