保定市分散剂厂

1. The role of dispersants in coatings.

  涂料中所用的颜料绝大多数是以初级粒子的附聚体和凝聚体混合形式存在的，如果不能将这些大小不一的颜料粒子分散为更细小的粒子或初级粒子，并使其成为不再聚集或絮凝的稳定分散体系，则会产生絮凝、返粗、沉淀、浮色发花、光泽度降低、着色力及遮盖力下降等缺陷。

Most of the pigments used in the coatings are in the form of the agglomerate and agglomerate of primary particles. If they can not be dispersed into smaller particles or primary particles, and make it a stable dispersion system that is no longer aggregated or flocculated, flocculation, roughing, precipitation, and flocculation will be produced. Defects such as floating color, flower glossiness, gloss reduction, coloring power and hiding power decrease.

 分散剂就是能够提高颜料分散体系稳定性的界面活性物质，添加在液体介质中的分散剂能吸附在粉碎成细小微粒的颜料表面构成吸附层，产生电荷斥力和空间位阻效应，防止分散了的颜料粒子再度形成有害的絮凝，可保持分散体系处于稳定的悬浮状态。

The dispersant is the interface active substance which can improve the stability of the pigment dispersion system. The dispersant added in the liquid medium can adsorb the adsorbed layer on the surface of the pigment that is crushed into fine particles, and produce the charge repulsion and the spatial steric effect to prevent the dispersing of the pigment particles to form a harmful flocculation and keep the dispersion. The system is in a stable suspension state.

二、分散剂的分类  

Two. Classification of dispersants

颜料分散过程比较复杂，但有三个作用是最主要的，即润湿作用、解聚集作用和稳定化作用，只有当润湿、解聚集和稳定化这三者能协同作用，颜料才能均匀、稳定地分散于涂料中。使用适宜的润湿分散剂可同时提供颜料润湿、解聚集和稳定化的作用，不仅可缩短研磨分散的时间，降低研磨体系的粘度，提高颜料的着色力和遮盖力，而且能防止颜料的絮凝、返粗、沉淀，提高涂料贮存稳定性，保证颜料始终处于良好的分散状态，保持颜色的均匀性。颜料分散剂大多数既具有润湿功能又具有分散稳定作用。

The process of pigment dispersion is complex, but the three main functions are the wetting, depolymerization and stabilization. Only when the wetting, depolymerization and stabilization of the three can synergy, the pigment can be dispersed evenly and steadily in the paint. The suitable wetting dispersant can simultaneously provide the effect of the wetting, depolymerization and stabilization of the pigment. It can not only shorten the time of the grinding and dispersing, reduce the viscosity of the grinding system, improve the pigment's coloring force and cover power, but also prevent the pigments from flocculation, roughening and precipitation, raise the storage stability of the paint and guarantee the beginning of the pigment. They are in good dispersion and keep the color uniformity. Most of pigment dispersants have the function of wetting and dispersing and stabilizing.

常用分散剂的化学结构主要有：

The main chemical structures of the commonly used dispersants are as follows:

①低分子量的羧酸酰胺盐及电中性的长链羧酸多氨基盐，拥有较多吸附基，可在颜料表面形成牢固的吸附层，提高了颜料分散的稳定性，起到防止浮色发花作用；

The carboxylic acid amides with low molecular weight and the polyamino salt of the electrically neutral long chain carboxylic acid have more adsorbates, which can form a solid adsorption layer on the surface of the pigment, thus improving the stability of the pigment dispersion and preventing the floats and flowers from floating.

②高分子量羧酸酯类聚合物，通过带高分子链的基团吸附在颜料表面而形成空间位阻控制，防止颜料絮凝，保持颜料分散体系的稳定性；

(2) high molecular weight carboxylic acid esters (HMW) are adsorbed on the surface of pigment with polymer chain groups to form the space resistance control, prevent pigment flocculation and keep the stability of the pigment dispersion system.

③含锚定基团的高分子聚合物或嵌段共聚物，锚定基能牢牢固定在颜料表面，而较高分子量的溶剂化链可有效地分散在漆料中，增加吸附层的厚度，提高分散稳定性；

The anchoring group can be firmly fixed on the surface of the pigment, and the solvent chain of high molecular weight can be effectively dispersed in the paint, increasing the thickness of the adsorption layer and improving the dispersion stability.

④多价羧酸聚合物，含较多羧基，极性很强，可使涂料形成触变性流体，使颜料形成可控絮凝分散状态，对防止浮色发花很有效。

Polycarboxylic acid polymers, containing more carboxyl groups and very strong polarity, can make the coating form thixotropic fluid, and make the pigment form a controllable flocculation and dispersion state, which is very effective for preventing the floatation of floatation.