Many times, we talk about anti-cratering and leveling agents. In fact, anti-cratering additives and leveling agents are two different additives, but many times, some leveling agents (especially silicone leveling agents) ) Has a good anti-crater effect, so the two are often mentioned together. Ink formula, UV / EB An additive should be used as an anti-cratering additive. The ability to reduce surface tension is the only indicator to determine its anti-cratering ability. Secondly, it is compatibility and other factors. An additive reduces surface tension. The stronger the ability, the stronger the anti-cratering ability. Our commonly used oil-resistant agents such as 47V500 are one of the most common anti-cratering additives, which can reduce the surface tension to about 22, which is much lower than The surface tension of various common resins and additives, such as Deqian's 435, can reduce the surface tension to 20-21, and stronger anti-cratering additives such as Tilo-235 can reduce the surface tension to below 19. .

             According to the basic principle of paint film leveling, the ultimate power of leveling comes from surface tension. Although too low surface tension can provide excellent anti-cratering ability, sometimes it will adversely affect the leveling. Usually, an anti-shrinking hole helps If the surface tension of the agent is lower than 22, it will adversely affect the leveling. In other words, a good anti-cratering aid is not always a good leveling agent. The principle of the leveling agent is different. Generally speaking, the role of the leveling agent is to spontaneously migrate to the surface of the paint film after being added to the coating system, providing uniform surface tension and maintaining the surface tension throughout the paint. During the film drying process (including the two major processes of solvent volatilization and resin cross-linking), no major changes occurred.

               The quality of a leveling agent depends on its ability to provide uniform surface tension, and has no direct relationship with the level of surface tension. Only according to the principle of minimum energy in physics, only the process of reducing the energy of the system is spontaneous. Therefore, if an additive wants to spontaneously migrate to the surface in the system, it must be able to reduce the surface energy of the system. The ability of the system surface tension, from this point, all leveling agents have a certain ability to reduce the system surface tension, that is, have a certain ability to prevent shrinkage. 7 ~ Generally, the surface tension of silicone-based additives is lower. Compared with acrylate-based leveling agents, silicone leveling agents have lower surface tension and stronger anti-cratering ability, and fluorine modification. The surface tension of the acrylate leveling agent can be changed within a large range (from about 30 to less than 20) according to the level of fluorine content, which means that as long as the fluorine-containing additives are not prevented, Shrinkage is very strong, for example, when the fluorine content is very low ("2% time", its anti-cratering ability is only slightly stronger than the ordinary non-fluorine acrylate leveling agent, which represents the product is EFKA-3777, When the fluorine content is increased (close to 10%), its anti-cratering ability is close to the level of silicone additives. The representative product is EFKA-3600. When the fluorine content is further increased, its anti-cratering ability is further improved, which can exceed the ordinary silicone The level of leveling agent, due to the high cost of high fluorine content products, currently related products are only used for some special purposes, such as FC-4430. For silicone additives, especially modified silicone oil additives, with Different anti-cratering structures The forces are also very different. The most important parameters that affect the anti-cratering ability are the silicon content and the type of substituent groups. The usual polyether-modified dimethyl siloxane-based additives, as the silicon content increases , Anti-cratering ability will increase; and when some methyl groups in dimethylsiloxane are replaced by long-chain alkyl or aromatic groups, the surface tension will be further increased, that is, the anti-cratering ability will be further weakened. Water-based adhesive formula Water-based resins have concluded that special anti-cratering additives usually have a certain negative impact on leveling, and leveling agents usually have anti-cratering capabilities. Their anti-cratering capabilities are related to their chemistry. Structure-related, usually silicone leveling agent has a stronger anti-cratering ability, followed by fluorine-modified acrylate, and finally the usual acrylate leveling agent.