免清洗助焊剂

免清洗助焊剂与溶剂清洗型、水清洗型助焊剂相比,具有无松香、不用清洗处理、无接触故障、无卤化物、焊接质量好等优点,是环境友好产品。文章详细介绍了国内外主要免清洗助焊剂的活性成分、溶剂和特殊成分,并介绍了免清洗助焊剂的铜镜腐蚀测试、铬酸银试纸测试、表面绝缘阻抗测试和软铣焊性试验等4种测试方法。     

无卤素无松香免清洗助焊剂的研制

针对目前助焊剂含有卤素、松香等问题,文章以丁二酸、苹果酸、松香醇、松香酸甘油脂、TX-10、无水乙醇、异丙醇等为原料,经过多次实验,最终获得无卤素无松香型免清洗助焊剂。该助焊剂不含卤素,绝缘性能好,无腐蚀性,性能非常优异,能够满足助焊剂的需求。     

NCSF—1新型免清洗助焊剂的研制

报道一种不含卤素，松香和树脂，低固含量新型免清洗助焊剂的研制及其市场应用前景。     

电子封装用免清洗助焊剂的研究进展

介绍了助焊剂的作用及其分类;总结了免清洗助焊剂的特点、种类和检测方法,介绍了几种新型免清洗助焊剂及其研究进展;对免清洗助焊剂的成分如活化剂、溶剂、表面活性剂和添加剂的功效做了说明,指出了存在的一些问题,并展望了今后的发展方向。     

低固免清洗助焊剂的研究与制备

研究了免清洗助焊剂的配制及合成工艺,通过微胶囊化对助焊剂活性成分预处理,得到稳定无腐蚀性、残留少的低固免清洗助焊剂,并对所配制助焊剂在软钎焊性、固含量、腐蚀性、卤素含量和酸度等方面进行了性能测试。结果表明:采用复配的有机酸活性物质满足预期要求;制备的免清洗助焊剂多项性能满足规范要求,解决了助焊性与腐蚀性的矛盾。     

电子封装用无卤素免清洗助焊剂的研制

研制了一种新的用于电子封装的无卤素助焊剂,并参考日本工业标准和相关国家标准对其进行了全面的性能测试.结果表明,该助焊剂在可焊性、绝缘性、腐蚀性等方面均符合标准,且具有焊接效果良好、无卤素、无毒、环保,焊后免清洗等优点.     

国外信息

劳伦斯读书笔记(十八) ▲日本公开昭60-261,689和61-09,992及其它一些相关专利介绍了制备膏状或乳状助焊剂的方法。制法;将已粉碎的助焊剂细粒悬浮于一种浆乳或粘液内,其成分为各种松香衍生物如松香甘油酯、其它松香酯或松香,溶剂为高沸点型,如丁基卡必醇,用来使物料软化至膏或浆乳的稠度。     

专利集目录

中国专利全集　第一集 (2 40元 )1、浅色改性松香酚醛树脂的制造方法2、用松脂制造松香改性酚醛树脂的方法3、高得率无酸渣制备聚合松香的方法4、以松脂为原料催化加氢制二氢或四氢脂松香5、马来酐改性松香甘油酯的制造方法6、松香专用包装袋7、自动温控电热松香炉8、弦乐器松香盒9、氢化松香的制造方法1 0、以松脂为原料生产歧化松香的方法1 1、无卤素非松香型低固含量免清洗助焊剂1 2、含巯氧吡啶锌、氧化亚铜和松香的油漆1 3、氢化松香酸作为生产聚碳酸酯和聚酯碳酸酯的链终止剂的用途1 4、利用造纸厂制胶锅自制分散松香胶的装置1 5、全…     

助焊剂系列化合物专利信息

一种SnZn系无铅钎料用助焊剂及其制备方法;一种用于无铅焊的低固含量免清洗助焊剂;无铅软钎焊料丝用无卤素助焊剂及制备方法;无铅软钎焊料丝用助焊剂及制备方法;     

专利集目录

中国专利全集　第一集 (邮购价 2 40元 )1、浅色改性松香酚醛树脂的制造方法2、用松脂制造松香改性酚醛树脂的方法3、高得率无酸渣制备聚合松香的方法4、以松脂为原料催化加氢制二氢或四氢脂松香5、马来酐改性松香甘油酯的制造方法6、松香专用包装袋7、自动温控电热松香炉8、弦乐器松香盒9、氢化松香的制造方法1 0、以松脂为原料生产歧化松香的方法1 1、无卤素非松香型低固含量免清洗助焊剂1 2、含巯氧吡啶锌、氧化亚铜和松香的油漆1 3、氢化松香酸作为生产聚碳酸酯和聚酯碳酸酯的链终止剂的用途1 4、利用造纸厂制胶锅自制分散松香胶的装置1…     

麦芽糖醇的纳滤浓缩

为了节约能耗,采用D和G 2种纳滤膜对麦芽糖醇进行了提纯和浓缩研究。实验中用G膜去除麦芽糖醇中的多糖醇,用D膜除去山梨糖醇和水分。研究结果表明:渗透液的通量随压力、循环流量和温度的增加而增大,而随物料质量分数的增加而减小;另外,截留率随压力和循环量的增加而增大,而随物料的质量分数和温度的增加而减小。综合考虑操作条件对分离效果的影响,最后确定了适宜的操作条件,对于D膜,操作压力为1.2—1.5 MPa,循环流量60—100 L/h;对于G膜,操作压力为1.0—1.2 MPa,循环流量40—60 L/h,操作温度均为40—45℃。     

An analysis of fine dry grinding in ball mills

The kinetics of dry grinding of several cement clinkers and two coals were investigated in a laboratory tumbling ball mill. The kinetic process is first-order at first, but the rates of breakage decrease as fines accumulate in the bed. It was demonstrated that the slowing of the breakage rates applies to all sizes in the mill, indicating that the cushioning action of fines affects the whole breakage process, even though mill power remains constant. Tests on cleaning or non-cleaning the balls showed that the major factor was not the build-up of a coating on the balls. Radio-tracing tests showed that the effect was not due to pelletizing of fines into larger particles. The quantitative magnitude of the cushioning action was different for different materials. It is, therefore, postulated that cushioning is affected not only by air trapped in the bed of fine particles but also by the cohesive attraction of fine particles, which is a function of the material.     

Effects of bubble coalescence dynamics on heat flux distributions under bubbles

Bubble coalescence events and single bubble nucleation, growth, and departure were observed with a charge‐coupled device (CCD) camera synchronized with a high‐speed data acquisition system measuring the heat fluxes at different positions underneath the bubble. Four different kinds of coalescence events took place with characteristic heat flux signatures for each type of event. The heat transfer measurements under four typical heaters representing different positions under the bubble showed very different heat flux characteristics during each ebullition cycle. The results show that transient conduction due to the movement of the contact line during bubble interactions, sliding, stretching, and oscillating is the main mechanism resulting in the high heat transfer rates during coalescence. Fast evaporation of the liquid layer trapped between the two bubbles and higher heat fluxes near the contact line as the microlayer evaporated also generate high heat flux spikes but have less influence due to their short duration and small influence area. © 2012 American Institute of Chemical Engineers AIChE J, 59: 1735–1745, 2013     

新型酯化反应器的研究

根据酯化反应釜的工艺要求提出了2种新的换热器模型,运用实验和模拟2种方法,以同功率下循环流量的大小为着眼点,对不同形式换热器模型的反应槽进行研究,测试了搅拌器的流量准数和功率准数,得出:同功率下桨在套式和板式换热器模型产生循环流量都大于盘管换热器。还通过对搅拌槽内部流场的模拟讨论了3种新型换热器模型的内部流场变化,并对2种新式换热器模型提出了优化方向。     

陶瓷微滤膜分散传质性能

引　言近年来 ,国内外对膜法制乳的研究已做了相当多的工作[1～ 7] ,并取得了良好的结果 .膜法制乳即以微滤膜为分散介质制备乳液的方法[8] .研究结果证明 ,采用膜分散制乳的方法可以得到液滴直径小且均一的稳定的乳液 .由于微滤膜的孔隙率较大 ,这种方法所需压力很小 ,能耗小 ,粒径可小于 10 μｍ,这是传统的分散方法无法达到的 .由此可见 ,膜法分散是理想的分散方法 .目前工业中的萃取操作多采用传统的分散法 ,分散的液滴粒径大 (1ｍｍ左右 ) ,比表面积小 ,滴内传质速度小 ,萃取效率低 .而膜法分散应用于萃取 ,传质面积和滴内传质速度比传…     

Distribution of Two‐Phase Flow across 2.7‐mm Vertically Split U‐Type Junctions

A visual observation of the two‐phase flow across vertically split U‐type junctions and its flow redistribution inside two 2.7‐mm diameter smooth tubes with curvature ratios (2R/D) of 3 and 7, respectively, are reported. The range of mass flux is between 100 and 700 kg/m²s and quality (x) ranges from 0.001 to 0.5. The ratio of liquid distribution between the upper and lower outlet legs is related to the inlet flow pattern, but its influence is reduced at higher mass flux. The difference in liquid flow rates in the lower and upper legs is significantly affected by gravity at a small inlet mass flux, but this difference becomes less profound when the inlet mass flux is increased. The difference between the liquid flux in the upper and lower leg is reduced for the smaller curvature radius due to the reduced effect of gravity between the upper and lower legs. However, there is no consistent trend of gas flow distribution across the U‐type junction as compared to liquid flow distribution. The air mass flux in the upper and lower legs always increase with an increase in both gas quality and the total mass flux.     

助熔剂对甲基磺酸盐镀锡板性能的影响

研究了甲基磺酸盐体系镀锡生产中两种不同的助熔剂对镀锡板耐蚀性和涂装性能的影响。结果表明:对耐腐蚀性能而言,无机盐类助熔剂明显优于烷基磺酸类助熔剂。与采用烷基磺酸类助熔剂时相比,由于采用无机盐类助熔剂形成的钝化膜量略高,且其中热稳定性较好的组分Cr₂O₃较多,因此漆膜与其镀锡板的附着性能略好,但因钝化膜中Cr(OH)₃偏低而抗硫性略差。镀锡板生产前需要综合考虑用户对产品的功能要求来选择适宜的助熔剂。     

不同国产纳滤膜对饮用水中氟离子的去除影响研究

选用两种国产纳滤膜NF1和VNF2进行除氟的实验研究,考察了不同的原水pH、操作压力、进水F-浓度、温度以及腐殖酸的浓度对纳滤除氟截留率以及膜通量的影响.实验结果表明:VNF2膜的截留率高于NF1膜,而膜通量则低于NF1;同时两种膜的最佳操作条件为pH在6.5～7.0,温度在18～23℃,操作压力为0.4 MPa,进水...     

聚合物添加剂对流动沸腾传热与减阻的研究

研究了两种不同相对分子质量 (2 5 6× 10 4 和 85 5× 10 4 )的聚合物添加剂聚丙烯酰胺 (简称PAM )在垂直铜管内对水的流动沸腾传热的强化情况 ,研究了添加剂水溶液浓度、质量流率、热通量等对流动沸腾传热的影响 ,根据测得的稀溶液在垂直铜管内流动沸腾的总压降 ,用Martinelli分离流模型求得了相应的摩擦压降。结果表明在低热通量下 ,在适当的浓度范围内 ,两种不同分子量的PAM不仅可提高流动沸腾传热系数 ,还可降低流动沸腾的阻力。研究还表明 ,在相同操作条件下 ,在同样质量浓度下 ,两种不同分子量的PAM对水流动沸腾具有较为相近的强化传热与减阻作用     

纳滤和反渗透膜形貌结构与膜性能关系探索

纳滤和反渗透膜表面形貌结构、亲疏水性的性质与膜脱盐率、水通量等性能存在一定关系。对几款商用纳滤、反渗透膜进行表面形貌结构、表面粗糙度、亲水性表征。结果表明,纳滤膜表面平整粗糙度低、亲水性强、脱盐率较低,但水通量高。反渗透膜表面存在大量疏松的峰谷结构,比纳滤膜粗糙度更大、亲水性强。对比两款海水反渗透膜,推测调整反渗透膜"叶片"大小和数量可调节反渗透膜的脱盐率和水通量性能。