Hot technical inventory of water-based coatings

01 The color change of the living environment under the covid-19 epidemic

At a time of uncertainty like the new crown epidemic, people long for home design to feel fresh and clean, similar to the uniforms of emergency personnel

Color trend: The need for comfort and tranquility, while full of vitality, makes the living space more enjoyable, suitable for family and work activities

Cynthia Challener, CoatingsTech | JANUARY 2021

02 Antibacterial and antiviral coating technology

Bacteria are living microorganisms that can be killed by antibacterial agents, while viruses are non-living pathogens that cannot be killed but can only be rendered inactive

Creating a surface coating with relatively low surface energy can weaken the anchoring of spiny glycoproteins on the surface and use active chemicals to inactivate spiny glycoproteins and viral nucleotides

Copper ion, silver ion antimicrobial and antiviral technology

Microencapsulation technology + metal ion modification technology

Many commercial products at home and abroad claim that the virus can be inactivated by coating

03 Renewable biomass raw materials replace petrochemical raw materials

Sustainability concept proposed by the European Chemical Industry Council (Cefic)

• Reduce the carbon footprint and increase the bio-carbon (C14) content of the coating material

• Water-based technology → Bio-based technology

04 Nano material application technology

Nano materials, good volume effect and surface effect, effectively improve the mechanical properties, corrosion resistance and wear resistance of the material

Hot nano materials: silicon dioxide, titanium dioxide, graphene, zinc oxide, etc.

Graphene oxide surface functional groups

05 Amphiphilic Janus particle additive

The water-based paint needs to be hydrophilic and stable in the liquid state, and after the coating is dried, the coating needs to be hydrophobic;

Water-based coatings have good film-forming properties with low Tg, and high Tg (high surface hardness) is required for the coating film after drying
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The emulsion synthesizes amphiphilic Janus particles and is added to the water-based coating system.
After spraying, they will quickly migrate to the coating surface (active self-layering)
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The hydrophilic side of the Janus particles will continue to adhere to the adhesive constituting the coating, and the hydrophobic half will face the air interface, forming a durable hydrophobic coating on the dried coating
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 Surface chemistry map of Janus particles (left) and scanning electron microscope (SEM) image of Janus particles (right)

a) Schematic diagram of the coating structure; b) SEM image of the cross-sectional view of the coating structure; c) Surface hydrophobic angle

 06 Organic-inorganic hybrid technology

Emulsion Synthesis Method

07 Anti-icing coating technology

Deicing surface: deicing power Tice≤100kpa; natural deicing power≤20kpa
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Inspiration from nature: low surface energy + micro-nano structure → super-hydrophobic coating + micro-nano structure
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Liquid immersion surface (LIS) technology introduces a slip function in the liquid layer of the coating
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The Kendal adhesion theory, which uses the force required to remove rigid materials from the surface of an elastomer (Figure 1), breaks through the traditional thinking of superhydrophobic/low surface energy surfaces
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Kinetic energy must be absorbed through surface cracking (erosion) or converted into heat through elastic surfaces
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The parameter Wa refers to the adhesion work (surface energy) of the material
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The convex structure reduces the Wa value of the interface, thereby reducing the adhesion of ice
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Elastomer + slip layer technology designs elastic coatings with different degrees of cross-linking and embeds miscible polymer chains to achieve interface sliding
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After more than 100 deicing tests, natural deicing is still achieved

Figure 1 Anti-icing mechanism of rigid adhesion on elastic coatings

The three parameters are: adhesion work (wa), modulus (K) and thickness (t)

08 Co-reactive dispersant technology

The dispersant, usually a low T‎‎g‎‎ polymer, does not have any function.
It is located at the interface between the pigment particles and the continuous phase.
It will not become a part of the continuous resin phase and will play a decisive role in the barrier properties of the final coating.

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It can also produce the plasticizing effect of the final coating, thereby reducing the barrier properties
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