This paper gives a analysis to the chemism of PV99 leveling agents that improve powder coating’s flowing. PV99 leveling agent has properties as listed: reduce or eliminate defect on coating surface (i.e.: shrinkage, pinhole, skim, etc.), enhance the wetness, increase fluidity and fullness of coating surface, promote pigment’s dispersion, etc. It has wonderful performance in polyester/ Primid polyester series for surface’s improvement.

 

High-quality is based on research and continuously innovative product line. PV99, the latest leveling agent researched by Zhihua Chemical, it can effectively improve powder coating’s application property and can greatly perfect the coating surface. It is well known, good leveling agents should have 4 properties as listed below:

PV99 is a high effective leveling agents with properties as listed above. We successfully introduce hydroxyl or carboxyl organic ester compound to Polypropylene copolymer butyl, which greatly extent the property of ester thus made the product be widely applied to powder coatings. This leveling agent can applied to epoxy powder, epoxy polyester powder, and pure polyester powder.

 

By physical effects, ester group of PV99 Leveling agent can reduce the chemical and physical effect from pigment aggregation, reduce the formation of pigment aggregates and presence, and reduce surface tension of pigment particle, which can help the stability of pigment dispersions to ensure that pigment particles in the powder coating’s coloring effect. Especially for dark pigments, the surface of coating can be more vivid and clear in eyes. PV99 can add exclusively, with a bit or no dosage of other wetting agents.

With introduction of active groups, the effect of ester in Acrylate Copolymerical can be fully reflected. Ester group form monolayer, which gives the coating a wonderful level and smooth surface, then by optical interaction, refraction can appear, which made the coating a bright surface, just like the effect of solution coatings.

PV99 leveling agent has an obvious effect upon transport of hydrone in process of transport in molecule. It enables the water molecules produced by water molecules in pigment or produced in process of ester curing cross-linking, a rapid migration to coating surface and evaporate in short time, thus a good performance of coating forms. Especially in the hydroxyalkyl amide system, water produced in polymerization by Hydroxyalkyl amide and polyester hydroxyl in hydroxyl powder in process of powder coating’s curing period. Pinholes phenomenon may appear when the coating is above 100um, which reduce down the coating’s performance. With dosage of PV99 leveling agents, this phenomenon can greatly improved, just like the effect with dosage of TGIC series.

We adopt advanced philosophy of propenyl copolymerization, taking isopropanol as solvent, AIBN as evocating agent, Allylamine derivatives as polymer chain transfer agent, control the speed of reflowing and dropping in a low range, finally Acrylate Copolymerical synthesized with well distribution of MWD.

 

Appearance: White powder

Active ingredient: 66~68%

Density: 0.48~0.68%

Volatile: ≤0.15%

 

With hundreds of tests among PV99, leveling agents imported and domestic common-type, the results is listed in table 1, compared to domestic common-type leveling agent and coupling agents, PV99 comprehensively reduce the dosage of resin, table 2 for detail reference.

  Table 1: comparison of effects    

Table 2: Dosage of resin by different prescriptions with PV99, common-type leveling agent, coupling agent

 

As a newly developed and high-effective leveling agent, the strong application properties need to be tested by all users. Current research shows PV99 has good properties as listed below:

1. Fine performance in leveling the surface of coating; raise the glossiness with good view of the surface.

2. The powder coating can reduce or eliminate the defect of the surface, i.e.: shrinkage, pinhole or skim; It can enhance the wetness, increase fluidity and fullness of coating surface.

3. Other leveling agents can not substitute  the film coating effect of PV99 in Primid polyester series; it also has a good performance in powder transfer

4. It can greatly reduce ester content with using active coupling agent（Zhihua Chemical）together. Under condition that not to reduce the properties of protection and decoration, with PV99 it can greatly cut down the cost price.

 

 

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[3] Zhenfa Chen, Techniques of Powder coating and Paint Coating，Shanghai: Shanghai Scientific and Technological Literature Publishing House，87~93

[4] Sulan Feng ，Powder Coating，Beijing：Chemical Industry Press，76~83