分散剂的分子结构和在配方中应用的重要.doc

推荐 分散剂的分子结构和在配方中应用的重要性.散剂, 配方, 分子结构, 重要性, 应用分散剂的分子结构和在配方中应用的重要性.分散剂的分子结构和在配方中应用的重要性.王盛龙谈谈分散剂 摘要:分散剂的分子结构和在配方中应用的重要性.关键词:分散剂在涂料配方设计中有些存在很多的误区.认为分散剂无关紧要.其是不然,分散剂在涂料配方中起着非常重要的作用,它迁涉到,光泽,流平,丰满度,以及施工的性能和生产效益以及存储等等方面.现将Ciba的EFKA分散剂的组成及分子结构和应用提给大家也许有一些帮助.Wetting and Dispersing Agents润湿分散剂Dispersing agentsSolvent-based溶剂型分散剂China Road Show March 2004Martin PhilipoomWetting and Dispersing Agents润湿分散剂They should not be considered as member of the substrate-wetting group of surfactants which are used to improve the leveling of a liquid resin formulation or to prevent the formation of craters但润湿分散剂不应作为表面活性剂中用来提高液体树脂流平性或者防止缩孔形成的基材润湿剂的一员来考虑。Wetting and Dispersing Agents润湿分散剂The quality of a dry paint or ink film is strongly dependanton how finely and uniformly distributed are the solid particles in the resin matrix 涂料或者油墨干膜层的质量强烈地依赖于固体粒子在树脂体系中良好而均一地分散。 Defects like poor colour strength, insufficient hiding powerlow gloss and decreased weather resistance are typical examples known to the technician诸如着色力差，遮盖力不足，光泽低，耐候性降低等缺陷是涂料技术人员所知道的典型例子。Furthermore, a poorly dispersed system results inferiormechanical properties of the dry film而且，差的分散体系导致干膜的机械性能变差。To obtain a finely dispersed system, the solid-liquid interface has to be modified during the grinding step为了获得良好的分散体系，固液界面必须在研磨阶段得到改进。During grinding, the pigment agglomerates and aggregates are crushed to primary particles and the newly formed surfaces are wetted by the liquid carrier在研磨过程中，大块 颜料和颜料凝聚体被粉碎成接近初级粒子，同时新形成的表面被液体载体湿润。The use of a wetting agent can increasethe speed at which the liquid phase wets the pigment surface润湿剂的使用能提高液相润湿颜料表面的速度。This is important as the grinding step is the most time- and energy-consuming phase during the paint and ink production process 研磨阶段是 涂料和油墨生产过程中最耗时，耗能的重要阶段。Another important consideration is the consecutive stabilization of the fresh dispersion of the particles 另外值得重要考虑的是新的粒子分散体的连续稳定性Grinding flocculates 研磨 絮凝 Agglomerates凝聚体Primary particles初级粒子 Flocculates絮凝Flocculation can cause colour shift, sedimentation and changes in viscosity of the dispersion絮凝能导致分散体发生颜色偏移，沉降和粘度变化The origin of flocculation is found in the Brownian motion of particles絮凝的起因是建立在粒子布朗运动的基础上。Small particles (typically 0.01-1 micron) move randomly in the suspension, collide with each other and form flocculates, reducing theirtotal energy. The smaller the particles, the stronger the flocculation微小的粒子（粒径0.01-1微米）在悬浮液中自由移动，相互碰撞形成絮凝，降低总能量。粒子越小，絮凝作用越强。If, in addition to being smaller, their concentration is also high, theprobability of encounter is increased and the tendency to flocculationis increased 粒子越小，浓度越高，相遇的可能性越大，絮凝倾向越强。Stabilization mechanism稳定机理Scientifically, two main stabilization mechanisms can be distinguished: electrostatic and steric stabilization.按科学的方法，主要分为两种稳定机理：静电排斥和空间位阻Electrostatic stabilization takes place when particles bear the same electrical surface charge and as a result, repulsion take place当粒子表面带有相同的电荷而发生排斥时便形成静电稳定As this mechanism relies on the separation of ionic charges,it is mainly relevant in systems of high polarity like aqueous paints由于这种机理依赖于带电离子排斥，因此主要对于象水性涂料这种高极性体系有用 Electrostatic repulsion静电排斥 The charge around the particle is organized into a double layer in which each layer possesses equalCharge粒子周围的电荷形成一个双电层，每层带有等量的电荷。When two particles approach one another, their charged double layersoverlap and repulsion take place当两个粒子相互接近时它们所带的双电层发生交迭并产生排斥Electrostatic repulsion静电排斥At the same time, London-van-der-Waals forces leads to attraction of the particles同时伦敦范德瓦力使粒子相互吸引。If the attractive forces are stronger than the repulse forces, the dispersionwill be unstable. However, if repulse forces predominate, the system willbe non-flocculating如果吸引力大于排斥力，分散就不稳定。而如果排斥力占优，体系就不会絮凝。Steric stabilization is brought about by adsorbed polymers and applies to both water- and solvent-based sytems空间位阻稳定是由所吸附的高分子带来的作用，它对水性体系和溶剂型体系都适用。This stabilization is dependant on the structure and dimensions of the adsorbed polymer layer这种稳定依赖于吸附的高分子层的结构和厚度In general, effective steric stabilization has to fulfill several conditions: 一般说来，有效的空间位阻稳定必须具有几个条件：the particle surface has to be totally covered with dispersant粒子表面必须被分散剂完全包覆the layer has to be of sufficient diameter高分子层的直径足够大the polymer has to be strongly adsorbed on the surface to avoid de-adsorption upon collision or dilution of the dispersion高分子必须被有力的吸附在表面避免在分散体碰撞或稀释时脱吸。the steric chains should be linear and extend into the medium to buildup a protective layer空间位阻链应该是线性的并且可以伸展到介质中形成保护层Steric stabilization空间位阻稳定The polymer can adsorb onto a particlethrough the so-called “anchoring groups”or segments that have strong affinity forthe chemistry of the surface聚合物通过在粒子表面具有强烈化学吸附能力的“锚定基团”或者链段吸附在粒子上The remainder of the polymer can be seen as dissolved and can extend into the resin medium聚合物的其余链段能与树脂相混溶并能伸展到树脂介质中These extended parts of the stabilizing polymer become the first contactsbetween two approaching particles这些具有稳定作用的聚合物伸展开来的部分成为两个相互接近粒子最先接触的部分A certain degree of inter-penetrationbetween the polymer layers from theadjacent pigments particles is possible邻近的颜料粒子所带的聚合物层之间会有一定程度的互穿As the concentration of solvated chains increases with decreasing distance, the free energy of the system increases随着距离的减小溶解链段的浓度升高，体系的自由能也随之升高。As a result of osmotic pressure, the solvent molecules start to migrate intothe zone of the penetrating polymer layers and re-separate the two particles until a lower energy level is reached由于渗透压的作用，溶剂分子开始向聚合物层相互渗透的区域迁移并使两个粒子重新分开，直到达到一个较低的能量水平。In this way equilibrium is attained between penetration and repulsion以这种方式获得渗透与排斥之间的平衡The diameter of the absorbed layer determines whether the distanceBetween the particles is large enough to overcome the van-der-Waalsattraction forces between the molecules吸附层的厚度决定着粒子之间的距离是否足够大以克服分子间 的范德瓦力Minimum distance between two pigment particlesin a stable dispersion在稳定的分散体中两个颜料粒子间的最小距离Minimum distance between two pigment particlesin a stable dispersion在稳定的分散体中两个颜料粒子间的最小距离In practice it is generally accepted that a molecular weight of at least5000 g/mol is required to achieve sufficient distance (100Å is consideredto be optimal for most particles实际中通常公认的是要达到有效距离要求分子量至少在5000g/mol(对于大多数粒子100 Å的吸附厚度被认为是最理想的）In day-to-day practice, the paint and ink industries employlow molecular weight (2000 g/mol) as well as high molecular weight (5000-25000 g/mol) wetting and dispersing agents 日常实践中，涂料和油墨工业既使用低分子量润湿分散剂（ 2000 g/mol）也使用高分子量润湿分散剂（ 5000-25000g/mol) Conventional Wetting and Dispersing Agents5000 series 5000系列 传统润湿分散剂 High Molecular Weight Polymeric Dispersants 4000 series4000系列 高分子量聚合物分散剂5000-serie Conventional Wetting and Dispersing Agents5000系列传统式润湿分散剂Function and characteristics:功能和特性designed for inorganic fillers/pigments 为无机填料/颜料而设计reduction of surface tension at the solid/liquid interface在固/液界面降低表面张力 anchoring groups adsorb to charged surfaces锚定基团吸附到带电表面 good compatibility with the medium与介质有良好的相容性sep aration of inorganic particles by wetting通过润湿使无机粒子相互分开 stabilization of inorganic particles by controlled flocculation通过可控絮凝稳定无机粒子 Categorisation according to chemical structure依据化学结构分类Classes and typical examples of conventional W&D Agents.传统润湿分散剂的分类与典型例子 CATIONIC 阳离子型如：油酰胺 ANIONIC阴离子型如：钠盐ELECTRONEUTRAL oleylamine oleate电中性型油酰胺盐NON-IONIC 非离子型 aliphatic polyetherThe effectiveness of wetting and dispersing agents is determined bytwo moieties:润湿分散剂的效力由两部分决定：脂肪族聚醚the interaction of the polar head of the molecule with the surfaceof the pigment-分子的极性端与颜料表面的吸附作用the behaviour of the non-polar hydrocarbon tail in the medium非极性烷基尾链在介质中表现行为In certain polar media, free molecules are drawn to those alreadyattached to the pigment surface through apolar-apolar interaction ofthe tails. This interaction takes a reverse position in respect to the firstlayer of the molecules. 在某一极性介质中 ，游离的分散剂分子通过非极性尾链 间的吸附作用被拉向那些已经吸附在颜料表面的分子。这种相互所用使附于第一分散剂层上的分子处于翻转位置, 即非极性链段部分朝内,极性端基部分朝外.The polar heads will form hydrogen bonding interactions between different pigment units resulting in a network that enhanced the separation of the particles (controlled flocculation)那些朝外的极性端会在不同的颜料聚集体间形成氢键作用进而形成网状结构，这种网状结构增强了粒子的分隔（控制絮凝）This interaction is of great importance in this class of dispersants sincethe relative low molecule weight (800-1000) will not give sufficientsterical hindrance由于相对比较低的分子量（800-1000)不能提供有效的空间屏蔽，致使这种相互作用对于这类分散剂非常重要。The difference in the interaction density among the various types ofdispersants determines the grade of the controlled flocculation. Thisinteraction is strongly influenced by the amount of polar heads present in the liquid phase as well as the polarity of the medium不同类型的分散剂吸附密度的差异决定了控制絮凝的等级。这种吸附作用受液相中极性端数量和介质极性的强烈影响。Wetting and Dispersing agents 润湿分散剂controlled flocculation 控制絮凝如50系列的分散剂4000-series High Molecular Weight Polymeric Wetting and Dispersing Agents4000 系列高分子量聚合物型润湿分散剂4000-series High Molecular Weight Polymeric Dispersants4000系列 高分子量聚合物型分散剂In order to achieve a strong interaction between the surface of organicpigments and the dispersing agents, EFKA developed different types ofdispersants which have main common features: they are build of highmolecular weight polymers (5000-30000) which in general have apolyurethane or polyacrylate structure为了在有机颜料表面与分散剂之间获得强吸附作用，EFKA开发了不同类型的分散剂，这些分散剂的主要通性是：都是高分子量聚合物(5000-30000)，一般分为聚氨酯型结构和丙烯酸酯型结构。Main differences between the polymeric dispersants and the conventional wetting and dispersing agents:高分子量分散剂和传统式润湿分散剂的分别anchoring mechanismchemical structure化学结构锚定机理molecular weight分子量Classification of pigments and characterisation of the surfaces 颜料的分类和其表面性质Inorganics:无机： charged particles带电荷的颗粒crystal lattice 晶体点阵metal oxides as 金属氧化物如TiO2, Fe2O3, CrO3surface + (metal ions) and - (oxygen ions)表面（金属离子）和（氧化离子）surface of a rutile TiO2(octahedral arrangement)金红石型的TiO2表面（八面结构）distribution of the charges on the surface表面电荷的分布Organics: 有机 consist mainly of C, H, O and N atoms主要由C,H,O原子组成covalent bonds共价键conjugation with aromatic rings gives colour共轭型的苯环为发色团Perylen-Pigment PR 179苝红类Mono-azo-Type PY 154单偶氮类Isoindolin-Pigment PY 139异吲哚啉酮类Naphtol AS-Pigment PR 170偶氮萘酚类Anchoring mechanisms锚定机理Review: conventional w&d agents回顾：传统式润湿分散剂effective by interaction of the polar head with the surface of the pigment/filler and compatibility of the chain in the medium-通过极性端基对颜料/填料表面吸附同时非极性链与介质相溶而发挥作用strong affinity to inorganic surfaces (+ and - charges)对无机not effective with organic pigments (covalent bonds of C, H, N, O atoms)-对有机颜料无效（C,H,N,O原子的共价键）颜料表面具有强吸引力（正电荷和负电荷）Anchoring mechanisms 锚定机理Polymeric Dispersants: 高分子量分散剂anchoring groups that have ability to adsorb to organic surfaces (C, H, N, O atoms) and inorganic surfaces (charged)能够吸附在有机颜料表面(C,H,N,O原子)和无机颜料（带电荷）的锚定基团Physical adsorption:物理吸附：hydrogen bonding 氢键dipoleLondon/van-der-Waals forces 伦敦 范德瓦力-dipole intinteraction by numerous anchoring groups in one polymer chain聚合物链上的大量锚定基团的吸附作用eraction 偶极引力Anchoring mechanisms锚定机理Polymeric Dispersants:高分子量分散剂hydrogen bonding氢键Different electro negativities(strong bindings)不同的电极性（强键）dipole-dipole interaction偶极引力Anchoring mechanisms锚定机理： Polymeric Dispersants:高分子量分散剂：London-Van der Waals Forces 伦敦范德瓦力 (similar chemical structure)（相似的化学结构）Polymer backbone聚合物背脊 Polymer backbone聚合物背脊Anchoring mechanisms锚定机理 Polymeric Dispersants:聚合物分散剂：conventional W&D Agent polymeric Dispersants聚合物分散剂 传统润湿分散剂 remaining part acts as steric barrier preventing reflocculation caused by Brownian motion支链部分起空间屏蔽作用防止布朗运动引起的再絮凝Problems related to flocculation by insufficient stabilisation:由于不足的稳定作用引起絮凝而带来的问题：pigment flooding / rub-out颜poor colour stability颜色稳定性差料浮色不能通过指擦实验lack of gloss失光poor hiding power and colour strength遮盖力和着色力变差increased viscosity粘度升高Synaeresis色漆中颜料与基料分层Solved by efficient steric hindrance通过有效的空间位阻来解决上述问题The special properties of HMW-Polymeric Dispersing Agents: 高分子量分散剂的特殊性能Very efficient in preventing flocculation. 非常有效地防止絮凝They work with both inorganic and organic pigments.对有机颜料和无机颜料都起作用。A strong viscosity reducing effect.具有强烈的降粘效果This is important where high pigment loadings are being used.这对于使用高颜料含量的场合很重要Excellent compatibility.优异的相溶性。Only small quantities are required to stabilise the pigments without flocculation.只需要少量的分散剂就可以稳定颜料而不产生絮凝。High resistance to humidity and chemicals.高耐湿性和高耐化学性。HMW-Polymeric Dispersing Agents are film-forming polymers with a high resistance to water and saponification, this in contrast to conventional Wetting Agents.高分子量聚合物型分散剂是本身可成膜的高聚物，与传统的润湿剂相比具有高耐水性和耐皂化性。Calculation method for required amount of solid Dispersant on pigment颜料所需固体分散剂量的计算方法Inorganic pigments 无机颜料 10% of Oil Absorption value 吸油量的10 Organic pigments: 有机颜料 blue, green, violet: 篮、绿、紫25% of BET value BET 值的25yellow, orange, Red: 黄、橙、红 50% of BET value BET值的50%Carbon black pigments: 碳黑颜料20% of Oil Absorption value 吸油量的20Based on polyurethane聚氨酯型Chemistry: Polyurethanes (patented)化学成分：聚氨酯（专利产品）MW ca 5000 - 18000分子量在500018000 n ca. 2 - 10 Based on polyurethane 聚氨酯型The polyurethane Dispersants have a branched backbone with a three-dimensional net structure. On various places of this net structuredifferent anchoring groups are introduced聚氨酯型分散剂支化的主链具有三维网状结构。这种网状结构的不同位置引入了不同的锚定基团。Branched polyurethane有支链的聚氨酯Progress of history of polyurethane polymeric dispersants聚氨酯型分散剂的历史发展如EFKA40系列The new generation has started with the development of EFKA-4050. Itwas presented in 1998. One year later EFKA-4080 was promoted新一代的分散剂伴随着EFKA-4050的开发而开始发展，在1998年已做过介绍，一年后推出了EFKA-4080。The latest development is EFKA-4060 with very strong viscosity depressing properties最Based on polyurethane 聚氨酯型新开发的EFKA-4060具有非常强的降粘性。The main differences between EFKA-4046 and EFKA-4047 and the products of the new generation are mainly in the structure of the anchoring groups. EFKA-4046与EFKA-4047以及与新一代产品的区别主要在于锚定基团的结构EFKA-4046: rigid side chains刚性侧链EFKA-4050: EFKA-4080: flexible side chains 弹性侧链Based on polyurethane 聚氨酯型In addition EFKA-4060 has prolonged side chains另外EFKA-4060 还有延长的侧链EFKA-4060: prolonged side chains(non-polar)延长的侧链（非极性）EFKA-4050: short side chains(non-polar)短侧链（非极性）Based on polyurethane聚氨酯型By the extension of the non-polar side chains decreases the interaction between the polar hearts of the neighbouring polymers this results in a strong reduction of theviscosity, because no build up of a structure take place通过非极性侧链的伸展减少了相邻聚合物极性中心间 的相互作用，因为没有了结构阻力的关系从而导致粘度大大降低。Chemistry: Polyacrylates (patented)化学结构：聚丙烯酸酯（专利产品）MW ca. 5000 - 25000 g/mol分子量 500025000g/molAlkyl-, Polyether : solubility, compatibility and steric hindrance烷基，聚醚： 提供溶解性，相溶性和空间位阻Fluorocarbon-: depression of surface tension氟碳化合物： 降低表面张力Alkylamines-:anchoring group for pigment surface烷基胺： 吸附颜料表面的锚定基团Acidic groups:anchoring group for inorganic pigments酸性基团： 吸附无机颜料的锚定基团Based on polyacrylate 丙烯酸酯型The polyacrylates have linear structures with a C-C backbone that bears various functional side groups and short chains. They bear groups that participate in the anchoring of the pigment. Other playa role in the solvation of the acrylate in the liquid medium, or induce a sterical hindrance丙烯酸酯分散剂具有带C-C主链的线性结构，这种结构承载着用来锚定颜料的基团，其他链段提供丙烯酸酯在液体介质中的相容性或形成空间屏蔽作用。Lineair polyacrylate线性聚丙烯酯Based on polyacrylate丙烯酸酯型Linear polyacrylate 线性聚丙烯酸酯The main differences with polyurethane-based dispersants are the higher molecular weights of the polyacrylates. This together with theirexcellent compatibility makes them very suitable for those pigmentswhere PU-dispersants fail 与聚氨酯型分散剂的主要区别在于丙烯酸酯分散剂具有更高的分子量。这一点加上它优异的相容性使得它们非常适合分散那些用聚氨酯分散剂不好分散的颜料。Based on po