What should be paid attention to when using coupling agents

The theoretical dosage of coupling agent is to allow all hydrophilic reactive groups in the coupling agent to react with the hydroxyl or proton groups provided by the pigment and filler, and there is no need to be excessive. However, the actual dosage should be determined based on the particle size and surface functional groups of the filler to determine the most suitable dosage. The relationship between viscosity and the amount of coupling agent can be determined using viscosity measurement method.

The point where viscosity decreases the most is the most appropriate amount of titanium acid ester.

Based on experience, the dosage of coupling agent should be around 1-3% of the solid pigment and filler in the coating. The finer the particle size and larger the surface area of the pigment and filler, the more coupling agent should be used.

In water-based coatings, due to the lack of solvents and low wettability, the adhesion is not as good as corresponding solvent based coatings. Titanium ester coupling agents can form bridge bonds with polymers and inorganic substrates. Due to the introduction of polar groups (such as epoxy groups) in the coupling agent, the affinity with the substrate is increased, resulting in significantly improved adhesion. This is the most prominent advantage of titanium ester coupling agents in water-based coatings. Compared with silane coupling agents, it does not increase the hardness of the coating, but can improve its flexibility.

Titanate coupling agents are a novel class of chemical additives that have rapidly developed and widely used in many production fields in the past decade. There have been many reports on their synthesis and application abroad, and they are also receiving increasing attention domestically.

Titanium ester coupling agent is widely used in the coating industry and is a multifunctional additive, but it also needs to undergo practical application tests to achieve the best results. In order to achieve modernization of the coating industry, extensive research on the application of titanium esters in the coating industry must be carried out.