Water based coatings are used in crosslinking agents

Water based coatings are used in crosslinking agents

There is a large number of hydrating couplets on the market, as well as epoxy crosslinking agents, but not very often, and there are also applications of titanate coupling agents.

If you can choose the right fluid agent and the film agent to satisfy the above content, you may obtain better surface effect by using the filler with fine grain size. There are two types of additives commonly used: crosslinking agents; Functional packing.

The reason for the improvement in performance is to increase the density of the crosslinking, or to improve the density, or increase the area of the filling contact to reduce the amount of resin contact area.

The choice of rheological agent. In waterborne wood coatings system, rheological additives has a very important position, affecting all aspects of the coating, an ideal and effective rheological curve needs to have the role of two aspects:

1. The thixotropy:

Good thixotropy can solve the anti-sinking and anti-flow effect. More importantly, good thixotropy can keep the silver in onto the board, under the action of spray, latex particles tended to parallel arrangement of the state, it is especially important for water-based wood coatings.

Later liquidity, or from a higher perspective:

After spraying, the coating needs certain thixotropy to prevent the flow and keep the particles in order. In after the window film contraction causes the emulsion particles are further, the viscosity at this time as low as possible is helpful to arrange, as well as the coating flow flat (why in aqueous system, the influence of rheological additives convection flat is crucial, flow ping agent selection section will continue to elaborate).

Here is a simple introduction to the water system rheological agent, and the water-based coating system is used in the following three categories:

A) alkaline swelling; For example, the cellulose, the acid (ASE) class, which thickens the water and is sensitive to the pH;




Chinese name: Diethyl toluene diamine(DETDA)

Physical and chemical properties: light yellow transparent liquid, slightly soluble in water, soluble in alcohols, ethers, ketones and other polar organic solvents, and polyether, polyester polyol compatibility.

Density 1.022

Viscosity (20 ℃) ??mPa·ss290±10

Pour Point ℃-9

Boiling point of310°C

Flash Point°C161.1°C


B) associated PU type (HEUR); It is generally classified into three types: Newtonian type (commonly used in the field of construction coating), pseudo plastic and strong plastic (our system needs to use strong plastic). This type of thickening of particles is sensitive to surfactant and is not sensitive to pH values;

C) gas phase silicon dioxide, organic bentonite, wax type (hydrogen bonding).

For thixotropy, can see this line of thinking from all kinds of formula, such as choosing organic bentonite, waxes rheological additives (BYK some information of wax additives help many of directional) is discussed.

It is mainly based on the following points: 1. Not sensitive to the system's HLB values; It's very sensitive to pH.

This system can be used to design the rheological curve, and the last hope film-forming agent "to meet the need of type association thickener association" in the narrative, we look forward to in the system of pH in alkali, the alkali swelling rheological additives have stronger thixotropic, after onto the plate, due to the volatilization of neutralizer, system into acid, causing thickening effect, the system viscosity as low as possible, to increase the flow and packing orientation.

It is important to note that if it is not carefully designed for pH and neutralizing agents, the alkali disinflation agent itself will not be favorable. Some people have done special research on this, which is why the development of the HEUR rheology agent was developed. The HEUR is usually slightly weaker than the ASE or the cellulose class, but is very helpful for the system. Especially when spraying, the high shear viscosity (strong plastic) is higher than the base solution, so as to prevent the splashing, and the wet film is thicker, which helps to smooth the flow.

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Diethyl toluene diamine(DETDA)  http://www.yaruichem.com