German technical background  VOK-377 leveling agent

VOK-377 silicone surface additive for solvent-free, radiation-curing, solventborne coating systems, adhesives and printing inks to significantly reduce surface tension. Contains hydroxyl functional groups, does not contain solvents.

Product information 

Chemical composition 

Polyether modified polydimethylsiloxane solution containing hydroxyl functional groups 

Typical physicochemical data 

The data presented on this data page is typical and not a product specification. 

Density (20 °C): 1.02 g/ml 

Hydroxyl value (solid): ca. 45 mg KOH/g 

Storage and transportation 

Stir well before use. At temperatures below 5 °C, the product may delamination or become turbid. Heat to 20 °C and stir well. 

Application areas 

Coatings industry 

Product features and benefits 

Due to its high surface activity, the additive accumulates on the coating surface. Its activity allows the additive to be incorporated into the polymer network and anchored to the coating surface. VOK-377 improves surface slip, substrate wetting and tape peelability, even at low dose levels. Half the standard dose of conventional silicones is sufficient. If the additive is immobilized to the coating surface by its active group, these properties last longer than conventional non-reactive silicones.

Recommended Use 

VOK-377 reacts with resins via hydroxyl groups and is mainly used in solventborne and solvent-free two-component polyurethane systems, UV-curable coatings, polyester/melamine baking coating systems, and a range of waterborne systems. The high compatibility allows the additive to be used in the production of highly transparent varnishes without causing turbidity. 

Wood and furniture coatings

Cans listen to paint

Coil coatings

Leather finishing agent

Recommended dosage 

0.05-1% additive dosage (form purchased) is based on total formulation. 

The above recommended dosage is for reference, and the appropriate dosage needs to be determined through a series of tests. 

Addition method and processing guidance 

The additive can be added at any stage of the production process, including post-adding. 

Special considerations 

When the paint is used outdoors, weathering will remove the top layer of resin and additives from the coating. Testing must be carried out to determine whether these conditions will allow the additive to be effective for a long enough time. In order for the additive to be incorporated into the coating system through its functional groups, the coating needs to be carefully and evenly sanded before recoating or repairing to ensure sufficient adhesion. 

Printing inks and varnishes

Product features and benefits

VOK-377 is a highly effective silicone additive that improves substrate wetting of solvent-free UV-curable varnishes and printing inks, even at low doses. In most cases, half the standard dose of conventional silicones is sufficient. The significantly reduced surface tension makes the product particularly suitable for wetting demanding substrates and conventional offset inks. VOK-377 is effective in printing inks for high-speed printing machines. Since the additive is highly compatible with standard resins, it is also suitable for the production of highly transparent varnishes. When used in UV systems, VOK-377 is comparable to VOK-UV3510. The two products are interchangeable. For all VOK-silicone additives, VOK-377 is best suited for improving tape peelability in overprint varnishes. 

Recommended Use 

It is particularly recommended for gloss varnishes, flexo inks, offset inks and screen inks. 

Recommended dosage

0.05-2% additive dosage (purchased form) based on total formulation. 

The above recommended dosage is for reference, and the appropriate dosage needs to be determined through a series of tests.

Addition method and processing guidance 

The additive can be added at any stage of the production process, including post-adding. 

Adhesives & sealants 

Product Features & Benefits VOK-377 is a highly effective silicone additive that significantly reduces surface tension and thus improves wetting of demanding substrates.

The hydroxyl functional group of the additive can be incorporated into the adhesive substrate. The high compatibility allows the additive to be used in the production of highly transparent varnishes without causing turbidity. 

Recommended Use 

Particularly recommended for improving substrate wetting of UV adhesive systems. 

Recommended dosage 

0.05-1% additive dosage (form purchased) is based on total formulation. 

The above recommended dosage is for reference, and the appropriate dosage needs to be determined through a series of tests. 

Addition method and processing guidance 

The additive can be added at any stage of the production process, including post-adding.