0 引言
0 Introduction
涂料广泛应用于我们的日常生活中，对被涂件起到了保护、装饰及特殊功能作用。涂料主要由成膜物质（树脂）、颜填料、助剂和溶剂（或水）组成。随着工业的发展与生活水平的提高，颜料被越来越多地应用到涂料油墨工业当中，以赋予更好的表观效果。与染料不同，颜料通常不溶于所使用的介质，大多数情况下都是以聚集体的方式存在。要得到好的着色力、遮盖力及色度等，必须将颜料的聚集体打开并保持稳定。如果颜料没有分散好，许多缺陷就有可能发生，如：絮凝、失光、颜色偏移、浮色/发花、沉淀等。本文介绍了颜料及分散剂的结构，以及分散剂在颜料分散时所起的作用。
Coating is widely used in our daily life, and it plays a protective, decorative and special function to the coated parts. Coatings are mainly composed of film-forming materials (resins), pigments, fillers, additives and solvents (or water). With the development of industry and the improvement of living standard, pigment is applied more and more to the paint and ink industry to give better apparent effect. Unlike dyes, pigments are usually insoluble in the medium used, mostly in the form of aggregates. In order to obtain good tinting power, hiding power and chromaticity, the aggregate of pigments must be opened and kept stable. If the paint does not have good dispersion, many defects are likely to occur, such as flocculation, loss of light, color offset, floating color and precipitation / flooding. The structure of pigments and dispersants and the role of dispersants in dispersing pigments are introduced in this paper.
1 颜料的形态及粒径
Morphology and particle size of 1 pigment
在涂料中，颜料大多被制成悬浮液使用。
In paint, pigments are mostly made into suspensions.
颜料的粒径范围分布很宽，一般从0.05 μm到1 mm之间。但研究表明，当颜料的粒径在0.05 ~ 0.50 μm之间时，具有最佳的着色力、光泽、遮盖力和耐候性等。图1显示了不同颜料粒径的对比。
The particle size range of pigment is very wide, generally from 0.05 M to 1 mm. However, when the particle size of pigment is between 0.05 and 0.50 m, it has the best tinting power, gloss, hiding power and weather resistance. Figure 1 shows the comparison of particle sizes of different pigments.
颜料制造过程中形成的最小粒子称为原始粒子，它以单晶体或者一组晶体存在，粒径非常小。而原始粒子之间以面和面相结形成的团块，称为聚集体，聚集体比较紧密，一般的分散设备很难将其分散成原始粒子。而原始粒子和聚集体通过范德华力结合在一起，形成的较大颜料粒状团块，称为附聚体。附聚体粒子之间以点、边、角相接触，粒子间作用力小，可通过机械的力量将其分散成原始粒子或聚集体，见图2。
The smallest particles formed in the manufacture of pigments are called primitive particles, which exist in single crystals or a group of crystals, and the particle size is very small. The aggregates formed by the surface and surface of the original particles are called aggregates, and the aggregates are relatively compact. It is difficult to disperse the original particles into the original particles by the general dispersing equipment. The granular aggregates formed by the combination of the original particles and the aggregates through the van Edward force are called agglomerates. The particles of agglomerates are contacted by point, edge and angle, and the force between particles is small. The particles can be dispersed into original particles or aggregates by mechanical force, as shown in figure 2.
我们希望颜料分散后成为原始粒子的悬浮液（理想状况），至少也是聚集体和原始粒子的悬浮液。但体系的趋势是从高能态恢复到低能状态，故以微细颗粒分布的颜料容易聚集成絮凝体。从结构上看，絮凝体与附聚体非常相似，但絮凝体中颜色之间是树脂溶液而不是空气。分散剂的存在会阻止或减缓絮凝的发生。
We want the pigment to disperse and become the suspension of the original particles (ideally), at least the suspension of the aggregates and the original particles. But the tendency of the system is to recover from high-energy state to low energy state, so the pigment with fine particle distribution is easy to aggregate into flocs. Structurally, the flocs are very similar to agglomerates, but the color between the flocs is the resin solution rather than the air. The presence of dispersants can prevent or slow down the occurrence of flocculation.
2 颜料的分散过程
The dispersing process of 2 pigment
颜料的分散过程由润湿、分散、稳定3个步骤组成。润湿过程中，颜料表面的的空气和水气被树脂溶液所替换，固/气两相（颜料/空气）被转换成固/液两相（颜料/树脂溶液）。分散剂尤其是低分子型的润湿分散剂能加快润湿的过程。分散过程中，主要依靠机械能作用（冲击和剪切力），颜料的团聚态被打碎成较小的微粒，成为分散状态（均匀分布）。第三步是稳定的过程，分散剂用于保持颜料分散状态的稳定，阻止失控的絮凝，并依据颜料表面所吸附的黏结剂种类和分子结构，促使悬浮液获得稳定状态。分散剂尤其是高分子分散剂对颜料粒子的稳定起了很大的作用。
The dispersing process of pigment consists of 3 steps: wetting, dispersing and stabilizing. In the wetting process, the air and water vapor on the surface of the pigment are replaced by the resin solution, and the solid / gas phase (pigment / air) is converted into solid / liquid two phases (pigment / resin solution). Dispersants, especially low molecular weight wetting dispersants, can accelerate the wetting process. In the process of dispersion, the aggregation state of the pigment is broken into smaller particles and become dispersed (uniform distribution) mainly depending on mechanical energy (impact and shear force). The third step is the stable process, dispersants for pigment dispersion keep stable, prevent runaway flocculation, and on the basis of binder surface adsorption and molecular structure of pigment, to obtain the steady state suspension. Dispersants, especially polymer dispersants, play an important role in stabilizing pigment particles.
3 分散剂的作用
3 the role of dispersant
分散剂在涂料生产中发挥了非常重要的作用。分散体系的稳定能避免诸多的涂料问题及漆膜弊病，如果配方合理，适量地添加分散剂能够有效降低成本，改善涂料性能。
Dispersant plays a very important role in the production of coatings. The stability of the dispersion system can avoid many coating problems and paint film defects. If the formula is reasonable, adding dispersant properly can effectively reduce the cost and improve the coating performance.
3.1 提升光泽，增加流平效果
3.1 improve luster, increase leveling effect
有试验表明，完全相同的配方，采用不同的分散剂，得出的漆膜光泽会有明显的差别。例如，在某黑色卷材涂料体系中，不同的3种分散剂制得的涂料涂膜的20°光泽分别是69.7%、81.5%、77.1%。如果所采用的分散剂不恰当，颜色絮凝后变粗，其对光泽所起的作用类似于消光粉，自然会影响光泽。
Experiments show that the same formula, using different dispersants, paint film brightness will have obvious difference. For example, in a black coil coating system, the 20 degree gloss of the coatings prepared with 3 different dispersants is 69.7%, 81.5% and 77.1%, respectively. If the dispersant used is not appropriate, the color will be coarser after flocculation, and the effect on the luster is similar to that of matting powder, which will naturally affect the luster.
3.2 防止浮色发花
3.2 to prevent floating
防止浮色发花，是大家所熟知的分散剂的作用之一。选用合适的分散剂，无论是罐内浮色发花还是漆膜的浮色发花，都可以得到改善或消除。图3显示的是采用不同的分散剂制得的蓝漆与白漆按相同比例混合均匀后所得出的罐内浮色发花的结果。还有些分散剂，例如SN-2004，是受控絮凝类的分散剂，分子链中含有一些羧基基团，与颜料亲和的同时，还会互相形成氢键，从而使颜料粒子稳定，达到预防浮色发花的效果。
Prevent floating, is one of the dispersing agent known as. Choose appropriate dispersant, whether it is in the tank or floating film floating, can be improved or eliminated. Figure 3 shows the results are evenly mixed according to the same proportion with blue paint dispersing agent prepared with different white paint tank floating results. There are some dispersants, such as SN-2004, dispersant is controlled flocculation the molecular chain containing some carboxyl groups, and at the same time, dye affinity, but also with each other to form hydrogen bonds, so that the pigment is stable, to prevent the floating effect.
3.3 提高着色力
3.3 improve tinting strength
颜料分散和稳定得更好，其着色力会明显加强。图4显示的是采用不同的分散剂分散的黑浆，与白漆按相同的比例混合后的涂膜结果，可以明显看出其着色力的差别。
The pigment is dispersed and stabilized better, and its tinting power is obviously enhanced. Fig. 4 shows the difference of tinting power between the black pulp dispersed with different dispersants and the film mixed with white paint in the same proportion.
3.4 降低黏度，增加颜料载入量
3.4 reduce viscosity and increase pigment loading
采用合适的分散剂，所得的色浆黏度会明显降低。这样可以增加颜料的载入量，提高生产效率。图5是采用不同分散剂分散的大红色浆的黏度对比。
The viscosity of the paste will be reduced obviously by using proper dispersing agent. This can increase the amount of pigment loading, improve production efficiency. Figure 5 is the viscosity comparison of the red slurry which is dispersed with different dispersants.
3.5 减少絮凝，增加施工性和使用性
3.5 reduce flocculation, increase workability and usability
许多人在评估分散剂时，都会做指研试验。如果分散剂搭配不恰当，指研的区域与未指研的区域会产生明显的色差，絮凝后的颜料着色力会下降，这给调色及涂料施工都带来困难。采用流板试验，也能观察
Many people do finger tests when they evaluate dispersants. If the dispersant does not match properly, there will be obvious color difference between the studied area and the non reference area, and the tinting power of the pigment after flocculation will decrease, which will bring difficulties to the color matching and coating construction. The flow plate test can also be observed