Research on water resistance and salt spray resistance of dispersants in water-based systems

Summary

This article introduces a structured polymer dispersant with excellent performance.

Keywords: dispersant, water resistance, salt spray resistance

The application of wetting and dispersing agents in water-based coatings is very important.

This article mainly introduces a new type of water-resistant structural polymer dispersant, focusing on the performance of the dispersant in water resistance and salt spray resistance in one-component waterborne acrylic, two-component epoxy and two-component acrylic polyurethane systems.

The principle of dispersant resistance to water and salt spray

There are many factors that affect the water resistance and salt spray resistance of the dispersant, such as active groups, molecular structure, molecular weight and HLB value, etc.

Figure 1 »Principle of dispersant resistance to water and salt spray

Experimental part

Water resistance test

Water resistance test in one-component acrylic system

Experimental formula:

In this experiment, a commonly used acrylic emulsion in the market was selected, and the dosage of various additives was adjusted reasonably to make it a formula for experimentation.

Experimental methods and results:

Water resistance test is carried out according to HG/T 4758 waterborne acrylic resin paint type II room temperature self-drying one-component paint.
The test method is two coats, each with an interval of 24h, the total dry film thickness is 50±5μm, and the drying and curing time is 14d
.

After 24 hours of water resistance according to the industry standard, the experimental results are shown in Figure 2
.

It can be seen from the experimental results that in a single-component acrylic resin system, UNIQ®SPERSE 688 W has better water resistance than competing products under the same conditions
.

Figure 2 »Water resistance results of one-component acrylic system

Water resistance test in two-component acrylic polyurethane system

Experimental formula:

This experiment selects a commonly used hydroxy acrylic emulsion and HDI curing agent on the market, and adjusts the amount of various additives reasonably to make it a formula for experimentation.
The specific formula is shown in Table 2
.

Experimental methods and results:

Water resistance test is carried out according to HG/T 4761 waterborne polyurethane coating metal surface paint topcoat.
The test method is two coats, each with an interval of 24h, the total dry film thickness is 60±5μm, and the drying and curing time is 7d
.

After 48 hours of water resistance according to the industry standard, the experimental results are shown in Figure 3
.

Figure 3 »Water resistance results of two-component acrylic polyurethane system

It can be seen from the experimental results that in the two-component acrylic polyurethane resin system, UNIQ®SPERSE 688 W has better water resistance than competing products under the same conditions
.

Water resistance test in two-component epoxy system

Experimental formula:

This experiment selects a commonly used epoxy emulsion and water-based epoxy curing agent on the market, and adjusts the amount of various additives reasonably to make it a formula for experimentation.
The specific formula is shown in Table 3
.

Experimental methods and results:

According to HG/T 4759 waterborne epoxy resin anticorrosive coating primer, the water resistance test is carried out.
The test method is to apply two coats, each with an interval of 24h, the total dry film thickness is 100±10μm, and the drying and curing time is 14d
.

After 240 hours of water resistance according to the industry standard, the experimental results are shown in Figure 4
.

Figure 4 »Water resistance results of two-component epoxy system

It can be seen from the experimental results that in the two-component epoxy resin system, UNIQ®SPERSE 688 W has better water resistance than competing products under the same conditions
.

Salt spray resistance test

Experimental formula:

In this experiment, a commonly used salt spray-resistant single-component acrylic emulsion was selected, and the dosage of various additives was adjusted reasonably to make it a formula for experimentation.
The specific formula is shown in Table 4
.

Experimental method results:

Spray one line, the thickness of the dry film is 50μm, the drying and curing time is 3 days at room temperature, and the experiment is done after baking at 20°C for 8 hours
.
The salt water concentration is 5%, and the salt spray resistance time is 168h.
The results are shown in Figure 5
.

Figure 5 »Salt spray resistance test results

It can be seen from the experimental results that UNIQ®SPERSE 688 W has better salt spray resistance than competing products under the same conditions in the water-based acrylic system that requires salt spray resistance
.

in conclusion

(1) The dispersant has excellent water resistance and salt spray resistance through reasonable structural design and the introduction of functional solvation segments
.

(2) Experiments have shown that the dispersant has superior water resistance performance compared to competing products in one-component waterborne acrylic, two-component acrylic polyurethane and two-component epoxy systems
.

(3) Experiments have proved that the dispersant also has better salt spray resistance than competing products in the salt spray resistance system
.

references

[1] Wang Jianwei, Wang Zhengdong, Hu Liming, Molecular structure design of hyperdispersants [J], Progress in Chemical Industry, 1994, (4): 32-37

[2] Wang Jianwei, Wang Zhengdong, Hu Liming, Application of Hyperdispersants [J], Coating Industry, 1995, (1): 29-33

Source: Qi Pei, Wu Xingwei, Eucard Chemical (Shanghai) Co.
, Ltd.