Shear Thinning Rheology Modifier Additive for Water-based Paints
Characteristics of a Shear Thinning Rheology Modifier
As this rheology additive is shear thinning, it is also known as a strongly pseudoplastic, non-Newtonian fluid. This means that there is an inverse relationship between its shear rate and viscosity. As viscosity increases, shear rate decreases. Viscosity changes are dependent upon force.
This low shear thickener is a VOC-, APEO- and tin-free organic zirconium complex neutralized with ammonia. Benefits of a shear thinning rheology modifier include highly effective storage stability, as well as the prevention of settling and separation of pigments. It also improves viscosity stability after tinting with universal colorants in water-based coatings systems. Concentration levels need to be managed as too high a level can lead to excessive crosslinking, which may cause separation and structure loss. There is no need for biocides when using this product.
Borchi® Gel PN prevents long-term paint sedimentation and syneresis (photo shows coatings after 2 weeks of storage at 40ºC)
Using Borchi® Gel PN Rheology Modifier with Dispersants for Inorganic Pigments and Cellulosic Thickeners
Due to its rheological properties, Borchi® Gel PN can be used with our Borchi® Gen 1252 wetting and dispersing agent for titanium dioxide dispersions. Benefits of using both products together include the elimination of settling, and improved viscosity variance over time after extended heat age stability. They also provide high opacity and strong tint strength. There is no change in gloss or contrast ratio. Borchi® Gel PN is more effective than fumed silica in TiO2 dispersions.
Viscosity stability is better over time with Borchi® Gel PN for TiO2 dispersions when compared with fumed silica
Borchi® Gel PN can also be used with our Borchi® Gen 1757 wetting and dispersing agent for bismuth vanadate pigment dispersions. Benefits of combining these products include better storage stability and anti-settling of bismuth vanadate pigments.
Borchi® Gel PN in WB PY 184 dispersion brings anti-settlementation and long term stabilization of dense inorganic pigments. Viscosity profile does not impact the flow behavior of the pigment concentrate allowing for higher pigment loading in combination with Borchi® Gen 1757
When used with a cellulosic thickener, Borchi® Gel PN builds up shear viscosity and improves sag resistance. It builds a stronger rheological network that is resistant to water and solvent impact. This shear thinning rheology modifier additive has lower spattering tendencies compared to the cellulosic thickener. It’s thixotropic profile allows for superior sag resistance and leveling.
Borchi® Gel PN builds up viscosity and improves sag resistance when used with a cellulosic thickener
Other shear thinning thixotropic rheology modifier additives from Borchers include Borchi® Gel NA. Both additives are shear thinning rheology modifiers for water-based paints.
Shear thinning rheology modifiers for water-based paints like Borchi® Gel PN and Borchi® Gel NA prevent drops in viscosity when adding universal colorants
The level of Borchi® Gel PN or Borchi® Gel NA (which is neutralized with sodium hydroxide) is important. Too much can lead to excessive crosslinking which may cause separation and structure loss
Appearance Clear, colorless to slight yellowish liquid Non-volatile content NA pH NA Density 1.23 g/cm3 DIN 51757
Viscosity NA Solvent(s) Water
- Thixotropic additive for use in water-based coatings systems whose binders or additives contain free hydroxyl and carboxyl groups
- Strongly psuedoplastic and non-Newtonian rheology modifier
- Contains shear thinning behavior
- Develops viscosity in the low shear range to prevent settling and separation
- Improves viscosity stability after tinting with Universal Colorants in coatings
- Once applied, the structure rebuilds slowly for improved flow and leveling while retaining good sag resistance
- Wide range of polymer systems
- Vinyl acetate
- Styrene acrylic
- Surfactant stabilized polymers
- Wide range of polymer systems
- 0.5 – 2.0% on total paint formulation
The degree of thixotropy will depend on the type of reactive groups present in the system, the pH of the coating (ideally between 7.5 and 8.5), the level of the desired gel structure and the amount of Borchi® Gel PN used. The exact dosage should be experimentally determined. Borchi® Gel PN can be added to the mill-base or as a post add provided good mixing conditions are used.
Protect from the effects of weathering and store at temperatures between 5 and 30 °C. Once opened, containers should be
resealed immediately after each removal of the product.
Please refer to our safety data sheet for information relating to product safety.
SAFETY DATA SHEET
- Europe : EINECS
- Switzerland : EINECS
- USA : TSCA
- Canada : DSL
- New Zealand : NZIoC
- China : IECSC
- Korea : ECL
- Taiwan : NECI
- Philippines : PICCS