The main reason for the drying speed of water-based paint is here!

Quick-drying is the most frequently heard customer request for water-based coatings.

Although water-based coatings face the above-mentioned technical challenges, they will inevitably become an important member of the coatings field due to their environmental protection characteristics.

1.

Like all coatings, the performance of water-based coatings is largely determined by the resin used in the formulation.

a.

b.

c.

d.

e.

2.

 Water-based resin film formation and curing generally have several levels of mechanism.
First of all, the aggregation and fusion of emulsion particles is a mechanism that all emulsions must experience when they surface dry.
Then, the volatilization of water and other film-forming aids fully manifests the basic properties of the thermoplastic resin itself, which is the second stage of curing.
Finally, some emulsions introduce a cross-linking mechanism during the preparation, or introduce a cross-linking agent when the coating is used, so that the hardness of the film is further improved on the basis of the thermoplastic resin.
The cross-linking mechanism of this last step has a great influence on the final curing speed and degree of the film.
Common cross-linking mechanisms include oxidation cross-linking (such as alkyd resin cross-linking), Michael additive cross-linking (such as some self-cross-linking emulsion systems), and nucleophilic substitution cross-linking (such as epoxy, polyurethane, etc.
) ).
These cross-linking reactions are all affected by temperature, pH and other factors.
The relationship between the curing requirements of the system and other properties should be balanced when formulating.

3.
The amount and type of film-forming aids:

In theory, any resin solvent is a film-forming aid.
In practice, considering factors such as safety, cost, speed, etc.
, there are only a dozen common film-forming additives, mainly some high-boiling alcohols, ethers and esters.
These film-forming additives will have their own preferences for different water-based paint engineers.
Generally, an experienced engineer usually uses only two or three kinds of film-forming additives.
The main considerations are the distribution of reagents between water and resin and the distribution inside resin particles.
Especially when the water-based resin is a multi-phase resin, the selection and matching of the film-forming aids becomes particularly important.

4.
Construction environment:

 At the beginning of this article we discussed the issue of water.
It is precisely because of the characteristics of water that the construction environment of water-based coatings is higher than that of oil-based paints.
The main purpose is to control the temperature and humidity during construction as much as possible.
The construction of general formula should try to avoid high humidity environment.
If construction must be carried out under high humidity, the formula should be adjusted, or a resin with fast film-forming properties should be selected or the site should be isolated.