Grinding process and performance evaluation of water-based industrial resin-free color paste

Water-based industryResin-free color pasteGrinding process and performance evaluation

Paint industry:

Abstract:

​Three new dispersants with high efficiency and excellent performance were used to prepare 14 kinds of pigment pastes, and the compatibility of the pastes in four common binder resins was evaluated. Experimental results show that the water-based industrial resin-free color paste made of the three SAMASO & CPT dispersants of Samaso Chemical Company is in line with the water-based industry with strong versatility, excellent salt spray resistance, water resistance/alcohol resistance/excellent compatibility with different solvents. Paint requirements provide a new way for the development of water-based industrial paint pastes.

1 Preface

As the country pays increasing attention to environmental protection, many chemical companies are moving towards the emerging technological materials fields of energy saving, environmental protection and safety. The development of water-based industrial paint is a typical example. Water-based industrial paint mainly includes water-based resin connectors, water-based colorants, solvent water, co-solvents, and functional additives. Among them, water-based resin connectors have gradually developed into water-based emulsion type, water-based resin connectors based on actual application needs in industrial production. There are three series of latex type and water-dilutable type[1], and also include 5 varieties of water-based alkyd resin, water-based epoxy resin, water-based acrylic resin, and water-based polyurethane resin. However, in traditional water-based industrial paint coloring, the formulation reagents cannot be unified, resulting in limitations in the variety of additives available for each resin. For example, it is almost impossible to use one reagent to achieve stable uniformity for all pigment pastes and excellent blendability into all types of binder resins.

2 Preparation and testing of water-based resin-free color paste

2.1 Preparation materials

Pigments: Phthalocyanine blue, Changzhou North America; Phthalocyanine green, Zhenjiang; P.Y.154 yellow, Changzhou North America; P.Y.74 yellow, Changzhou North America; P.Y.83 yellow, Clariant; P.R.122 red, Hangzhou Lily; P.R.254 red, Hangzhou Lily; P.V.23 purple, Nubiola; R-706 titanium dioxide, DuPont.

Auxiliaries: SAMASO DP6210, SAMASO DP6211, SAMASO DP6213, triethanolamine, TEGO 810.

Resin: DSM Resin, Beijing Jinhuili, Tongde Chemical, Shanghai Xinhua Resin, Guangzhou Shiyuan Chemical, and customer sample evaluation

2.2 Preparation equipment and instruments

Electronic balance: One thousandth, METTLER; Blue high-speed dispersing grinder WJ-0.5, Shanghai Tianchen Modern Environment; 25 μm wire rod, Modern Environment XB-25; Oscillation machine: Foshan Shunde Jingqu Yi Intelligent Machinery Co., Ltd. company.

2.3 Preparation method of water-based resin-free color paste

Follow the formula sequence in Table 1. First add solvent water, dispersant, and defoaming agent to the dispersion tank, turn on the high-speed disperser, and use the dispersion disk to evenly dissolve the dispersant completely.

Secondly, add different toners in measuring units into the dispersion cylinder according to the formula proportion for dispersion; after dispersing until the toner is completely dissolved into the liquid, transfer the dispersed color slurry into an oscillating iron can or a glass jar, and seal it. Put it into the oscillating machine; adjust the oscillating grinding time to 6 hours.

After the shaking time is completed, take out all the samples and unseal them, add the remaining water and mix well to make up for the percentage, and filter it with a 200~400 mesh gauze to obtain the color slurry stock solution.

2.4 Water-based resin-free color paste performance testing method

1

Color difference test: When the system contains diluent, it is necessary to test the compatibility between the pigment and the diluent. Generally, the finger grinding method is used, that is, the fingers are used to make circles on the undried paint. The purpose is to show the difference between the surface and internal colors of the paint through the circular patterns [2].

2

Incorporation test: In the resin binder, test the compatibility between the pigment paste and the matrix binder. The test method is to add the pigment paste into the connector resin, mix the two through stirring or high-speed dispersion according to the conditions of use, and then apply the mixed paint on the glass plate using a wire rod, and Use visual observation and evaluation. After the coating film dries, if no obvious particles are observed with the naked eye, it indicates that the two have good compatibility.

3

Water resistance test: In addition to the appearance requirements, industrial paints also have stricter requirements for adhesion, weather resistance, and water resistance, in order to achieve the purpose of anti-corrosion and anti-rust. The test method is to directly soak the workpiece coated with color paste industrial paint in water, take it out after a few days, use a tool to scratch the surface of the workpiece, and observe the surface and scratched surface.

3 Performance test results

3.1 Color paste fineness

The fineness of all the obtained color pastes was tested using a fineness plate. The results showed that the fineness of the obtained color pastes were all ≦5 μm. Meets the fineness requirements of color paste for industrial paint.

3.2 Color difference of color paste in white dilute base

Add 12 kinds of pigment pastes into the resin containing white diluent according to the method described in 2.4 (1). After making the film, grind it with your finger and observe as shown in the figure below:

Compatibility of organic pigments and carbon black in white dilute paint

The results show that the 12 pigment colors have excellent compatibility in diluent-containing resins.

3.3 Incorporation test of color paste in different resin systems

Add 14 kinds of pigment pastes into the resin according to the method described in 2.4 (2). After making the film, observe it as shown in the figure below:

Compatibility of organic pigment paste and carbon black paste in water-based hydroxyl acrylic resin

The results show that the 14 pigment colors have excellent compatibility in resin.

3.4 Water resistance

Add the color paste into the water-based hydroxy acrylic baking paint resin, coat it on a rust-free iron sheet and bake it to form a film. Then put it into a water tank to soak for 7 days. Take it out and observe that the paint film does not appear wrinkled, whitish, hazy, etc. Phenomenon.

3.5 Alcohol resistance

Use absolute ethanol and color paste to dilute it at a ratio of 1:1, and observe whether there is any precipitation, flocculation, etc. of the pigment after the color paste is diluted.

Schematic diagram of the state after diluting the color paste with absolute ethanol 1:1

4 Summary

Three dispersants synthesized by polymerization technology are used to disperse water-based industrial paint pastes. The obtained pastes are added to white dilute resin and three types of resins respectively. The results show that the pastes not only have excellent stability, but also have Broad compatibility. Finally, the effect of dispersants on the water resistance of water-based industrial paints was evaluated, and the results showed that dispersants had no effect on the water resistance of industrial paints