汽车涂料产业发展前景

汽车涂料作为汽车的“外衣”,不仅要求有良好的防腐、耐磨和抗冲击性能,而且还要求漆膜丰满、鲜映度高、不泛黄,并且具有各种装饰效果。为了达到上述性能和装饰效果,一辆汽车往往需要多种涂料进行配套装饰。目前,世界汽车工业普遍采用的汽车涂料品种有阴极电泳漆(按膜厚分为薄膜、中厚膜和厚膜3种)、中涂层、面漆、罩光清漆、防石击涂料、汽车修补漆和塑料漆。采用的涂层体系有2道涂层体系(即厚膜阴极电泳漆和面漆)和3道涂层体系(即薄膜或中厚膜阴极电泳漆、中涂层和面漆)。根据车型的不同,单车用漆一般在25～55kg。     

细菌孳生对阴极电泳系统的危害及防治方法

在生产中阴极电泳生产线经常出现持续的电泳膜层增厚、外观粗糙等问题,造成电泳打磨返工量增加,电泳漆消耗量上升,从而影响到面漆后的外观质量.经过对电泳槽化学参数、电泳物理参数以及油漆材料的质量、细菌的检测分析发现,电泳系统孳生了细菌的生长,使得阴极电泳涂装生产线出现电泳漆膜外观粗糙、膜层增厚等问题.通过增设去离子水装置以及紫外线杀菌装置,定期投加杀菌剂,电泳漆ED5用磺酸代替乳酸,ED6用无机酸代替有机酸,有效地防止了细菌的生长.经过改进,电泳漆膜各项性能达到质量要求,面漆外观质量得到了提高.     

流平剂对阴极电泳漆性能和槽液稳定性的影响

论述了阴极电泳漆槽液中加入流平剂消除涂层缺陷的方法，并系统考查了加入流平剂后涂层的各种性能，试验结果表明，槽液中加入流平剂，是改进阴极电泳漆膜外观的有效方法。     

镀锌板表面有机硅烷-磷化复合膜与阴极电泳漆膜配套性研究

本文介绍了一种可以满足阴极电泳涂装要求的有机硅烷化的磷化处理液,对有机硅烷化的磷化转化膜进行电化学、耐碱性、溶出率、硫酸铜点滴测试,结果显示当有机硅烷和磷化成分配比为8：2时,其耐蚀性最好。通过分析入槽前干膜和湿膜的电化学等性能,发现无论是湿膜或干膜在一定条件下均能得到均一致密的膜层。讨论不同电泳电压、电泳时间对膜厚以及膜外观的影响,当电泳电压为150V、电泳时间为120s时,可形成性能优异的电泳漆膜。     

阳离子超细颜料色浆含量及电泳电压对阴极电泳漆效果的影响

为了改善阴极电泳漆漆膜的色泽、牢度、平滑度、致密与均匀度等性能,以有机颜料（P．Y．83）、十八烷基二甲基苄基氯化铵、去离子水制备了阳离子水性超细颜料色浆,并将其加入阴极电泳漆。探讨了阳离子水性超细颜料色浆含量及电压大小对漆膜外观、电沉积量及得色量的影响。结果表明：槽液电导率随着超细颜料色浆含量增加而增大;超细颜料色浆含量从4％增大到20％时,漆膜电沉积量从11．05∥m。增大到71．45g／m2,K／S值从10．5384增大11．0537;超细色浆含量过大,影响漆膜外观的平整性;在较低电压范围内,漆膜光滑、平整,电沉积量、得色量随着电泳电压的增大而逐渐增大;电泳的电压过高时,漆膜粗糙,出现气泡、橘皮等现象,电沉积量急剧增大,得色量急剧下降。     

晶态磷化工艺与阴极电泳技术的配套性研究

为了探究不同磷化膜与阴极电泳涂装的配套性效果,并研究不同工艺条件对配套性的影响,利用晶态磷化工艺制备的磷化样板作为阴极电泳的基板,考察了电泳电压、电泳时间、电泳温度、膜层耐碱性对电泳漆膜配套性的影响。结果表明:制得的常温低渣磷化膜和改性纳米SiO_2磷化膜均具有优异的耐碱性能,在电泳电压为200~240 V、电泳时间为120~180 s,电泳温度为25~30℃时均能够获得较好的电泳膜层。对电泳后的漆膜涂层进行附着力、杯凸、盐雾划叉等试验测试,同样表明上述制备的两种磷化膜和电泳有较好的配套性,电泳后的漆膜各项性能均能达到国家及行业标准要求。     

环氧丙烯酸阴极电泳涂料的研制及涂装工艺对涂膜性能的影响

通过接枝共聚的方法在环氧树脂主链上接枝丙烯酸酯类单体,再配以其他物质合成出自交联的阴极电泳涂料用的丙烯酸接枝环氧树脂,以此为主体树脂制备出白色的电泳涂料.探讨了阴极电泳涂料的电泳工艺参数对涂膜性能的影响.结果表明:在电泳电压为90 V左右,漆液固体分为16%,pH值为5.8,电泳时间为2.0～3.0min条件下.可获得...     

磺化煤在电泳涂漆中的应用

一、概述电泳涂漆的疵病与使用的电压、固体含量、pH值、温度、时间等工艺参数有关,也与漆种的质量及槽液杂质离子的存在有着密切的关系。由于生产周期的增长,无机离子在漆液中的含量将逐渐升高,严重影响电泳涂漆的质量。我们曾采用了多种方法来处理,都未能较好的改善漆膜的质量。通过反复试验、实践,采用磺化煤处理的方法,得到满意的效果,有疵病的电泳漆经磺化煤处理后,漆膜平整、光滑。     

甲丁醚化氨基树脂固化剂对丙烯酸酯型阴极电泳涂料漆膜性能的影响

氨基树脂固化剂在阴极电泳涂料中存在槽液稳定性较差等问题,限制了其在电泳涂料中的应用.通过对氨基树脂固化剂适当改性,用甲醇和正丁醇混合醚化六羟甲基三聚氰胺制备了甲丁醚化度不同的新型氨基树脂固化剂,研究了其在丙烯酸酯型阴极电泳涂料中的应用.结果显示甲丁醚化度适宜的氨基树脂固化剂可得到各项性能优良的固化漆膜,且可保证电泳槽液的稳定性.     

光固化阴极电泳涂料的制备与应用

光固化阴极电泳涂料具有节能、环保的优点.合成了可用于紫外光固化阴极电泳涂料的功能性树脂.首先利用丙烯酸-β-羟乙酯对异氰酸酯进行部分封闭,制备含异氰酸根的不饱和单体TDI-HEA,后期将含异氰酸根的不饱和单体接枝到酸化胺化环氧树脂E-55-NR3上,制得具有多官能度的水性感光树脂.通过考察电泳工艺对沉积漆膜效果的影响,得到最佳电泳工艺为:电压80 V,时间100 s.另外,还考察了闪蒸及固化条件对漆膜性能的影响.研究表明,闪蒸温度80℃、5 min下固化制备的漆膜具有优异的耐溶剂性.     

汽车用锌铁合金和热镀锌板材涂装性能的比较

以热镀锌钢板代替锌铁合金镀层钢板可降低汽车生产成本而不影响汽车涂装性能。对2种钢板作系列前处理后,采用随车挂板和贴板方法进行涂装,对2种板材的涂装性能进行了研究。结果显示：相同工艺条件下,两者的整体涂装性能相近,电泳防腐蚀性能接近,涂层厚度相同;两者的耐高温性能和附着力性能相同;热镀锌板的磷化层晶体尺寸更为均一,其电泳...     

阴极电泳涂料用主体树脂

电泳涂料的合成与应用是涂料行业的一个突破性进展。目前几乎所有的汽车工业用底漆及其它行业用的防腐底漆都采用电泳涂料 (漆 ) ,而其中 90 %以上又都是阴极电泳涂料。本文简要介绍了以环氧树脂、丙烯酸树脂、聚丁二烯树脂、聚氨酯树脂等为主体的阴极电泳涂料主体树脂和相关的化学反应。     

Electrophoretic deposition of HA/MWNTs composite coating for biomaterial applications

A composite coating of hydroxyapatite (HA)/multi-walled carbon nanotubes (MWNTs) has been fabricated by electrophoretic deposition (EPD). The nano powders of HA and MWNTs were dispersed in ethanol with total concentration of 0.005 g/mL and MWNTs 20% and 30% contents (wt). And the pH value of suspension was adjusted in a range from 4 to 5. After stabilization the mixture was ultrasonically treated for 3 h to form a stable suspension. Prior to the electrophoretic deposition, the titanium substrate was hydrothermally treated at 140 in NaOH (10 mol/L) solution for 6 h. A titanium sheet and circinal net of stainless steel were used as a cathode and an anode respectively, and a constant deposition voltage of 30 V was applied for 50-60 s in the EPD process. The thickness of the coatings was controlled from 10 mum to 20 mum. The samples of composite coating were then sintered in a resistance tube furnace in flowing argon at 700 for 2 h. The structure of the as prepared coating was characterized by SEM and XRD, and the bonding force of the coating/substrate was measured by an interfacial shear strength test. It is shown that the bonding strengths between the coating and the titanium substrate is as high as 35 MPa. The cell culture experiments indicate that the prepared composite coating of HA/MWNTs possesses good biocompatibility.     

SCC Behaviour of X-70 Pipeline Steel in Near-Neutral pH Solutions

The stress corrosion cracking (SCC) behaviour of X-70 pipeline steel in near-neutral pH solutions was studied via slow strain rate testing (SSRT). The results showed that the cracking mode of X-70 pipeline steel in near-neutral pH solutions was transgranular at different temperatures and applied potentials with the feature of quasi-cleavage. The pH value of the solution decreased with increasing the addition of CO2, which increased the susceptibility to SCC. SCC susceptibility increased as the applied potential moved towards the cathodic direction, suggesting that hydrogen induced cracking (HIC) dominated the cracking process at cathodic potentials. The slight decrease of pH values with decreasing temperature of the solution increased the susceptibility to SCC, which attributed to the change of solubility of CO2 in the solution at different temperatures. The propagating directions of SCC cracks were different at different potentials. At rather negative cathodic potentials, the cracks were almost perpendi     

低磁不锈钢表面处理工艺及防护涂层体系设计研究

研究了不同表面处理工艺对低磁不锈钢基材自身耐蚀性能及涂层附着性能的影响,通过电化学阻抗及耐阴极剥离性测试确定了适用于低磁不锈钢表面的防护涂层体系.研究结果表明,以棕刚玉为喷砂磨料对基材进行喷砂处理,不仅可以提高基材表面粗糙度,满足涂层高附着需求,同时可降低基材表面残留粒料对基材引起的电化学腐蚀.以环氧锌黄为底层的防护涂...     

Fabrication of submicrometer-sized gold electrodes of controlled geometry for scanning electrochemical-atomic force microscopy

A method for fabricating submicrometer-sized gold electrodes of conical or spherical geometry is described. By generating an electric arc between an etched gold microwire and a tungsten counter electrode, the very end of the gold microwire can be melted and given an overall spherical or conical shape a few hundred nanometers in size. The whole wire is subsequently insulated via the cathodic deposition of electrophoretic paint. By applying a high-voltage pulse to the microwire, the film covering its very end can then be selectively removed, thus exposing a submicrometer-sized electrode surface of predefined geometry. The selective exposure of the preformed end of the microwire is demonstrated by cyclic voltammetry, scanning electron microscopy, and metal electrodeposition experiments. The electrophoretic paint coating provides a low-capacitance, robust insulating film allowing exploration of a very wide potential window in aqueous solution. The submicrometer-sized electrodes can easily be turned into probes suitable for combined scanning electrochemical-atomic force microscopy by bending and flattening the gold microwire so that the tip is borne by a flexible enough arm. The good agreement between theoretical and experimental scanning electrochemical microscopy approach curves thus obtained confirms that only the very end of the tip, of predefined geometry, is exposed to the solution.