Analysis and solution of water-based paint shrinkage cavity and oil pocket

The surface defects of the coating film are mainly depressions, pinholes, and shrinkage or thick edges of the corners. There are two kinds of depressions on the surface of the coating film, one is circular depression and the other is hexagonal polygon depression. The depression on the surface of the coating film is caused by the surface tension gradient. Due to the change of the coating composition and the temperature change, the surface tension is uneven, and the fluid flows from the low surface tension to the high surface tension. As a result, depressions are formed on the surface of the fluid, also known as Maragoni effect, the shrinkage cavity with the edge bulging and the center sinking into a circle eventually appears. There is a substance with low surface tension in the center of the shrinkage cavity, which has a surface tension difference with the surrounding paint. The liquid fluid flows away from it (shrinkage crater pollution source) around it and flows into a depression-shrinkage crater

therefore. Reducing the source of shrinkage cavities that cause poor surface tension of the coating, increasing the viscosity of the coating and increasing the thixotropy are all beneficial to resist the formation of shrinkage cavities. Because the reasons for shrinkage cavities are different, and the treatment methods are different, we need to prescribe the right medicine. For the shrinkage cavities in the first and fourth cases, our company also has a good solution. We recommend our water-based anti-oil wetting agent 1070/2986. For the shrinkage crater caused by poor compatibility in the system, we recommend our water-based anti-shrinkage wetting agent 210/3013.

SN-1070 Water-based oil repellant

1. Typical performance:

1. Reduce static surface tension and dynamic surface tension, and improve the wettability of inks, coatings and adhesives on substrates.

2. It has reduced surface tension and good oil resistance

3. It has excellent miscibility with water-based resins and is used in high-gloss systems without reducing gloss.

4. Recoatability, and provide scratch resistance, slippery feeling, does not affect the silver row effect.

Features:

Water-based oil repellent 1070 can provide anti-oil, anti-shrinkage effect, can provide anti-scratch, and does not affect recoating, does not affect the arrangement of silver powder, and can be completely soluble in water. Especially suitable for water-based mechanical paint, water-based steel structure paint, water-based baking paint, etc.

Addition amount: of the total system amount: 0.1-2%

Anti-oil effect:

SAINO 210

Anti-crater wetting agent

I. Overview

SAINO 210 is an additive that can effectively improve the anti-cratering effect on difficult-to-wet substrates and contaminated substrates. It is a substrate wetting agent with excellent wetting and anti-cratering effects.

2. Physical parameters

Main ingredient: polysiloxane copolymer

Appearance: colorless to pale yellow liquid

Active ingredient: 100%

Solubility: soluble in water

3. Features and uses

1. Excellent anti-shrinkage effect, anti-shrinkage edge ability and good leveling.

2. It has good compatibility with the system and can effectively prevent defects such as shrinkage crater, orange peel and pinhole in the coating.

3. Does not affect the recoating of paint.

4. Efficiently promote the spreading, wetting and flow of the coating on the surface of the substrate, and has a rapid wetting and spreading effect for low surface energy substrates, especially to improve the wettability of the coating on difficult-to-wet substrates and contaminated substrates .

The scope of application:

Water-based wood paint, water-based industrial paint, release agent water based, water-based glass paint, water-based ink

5. How to use:

It can be used directly or added after dilution. It should be fully stirred during use to make it evenly dispersed. For best results, pre-test additions. The general addition amount is 0.1-1.0% of the total coating.