ORGANOCLAY

Due to its lipophilic properties, organoclay can be used to remove oil from water, and is used in water treatment systems. There are numerous organoclays commercially available for such diverse applications as water treatment, plastic reinforcement and coating additives. We selected one type of commercial organoclay (Bentone SD-1 made by Elementis) as most suitable for artists own use to amend their oil paint. The organoclay sold by Natural Pigments is an organic derivative of bentonite clay. It is very easily dispersed in oil and alkyd-based paint (mediums composed primarily of aliphatic and other non-polar to medium polarity substances). It can be added at any point in the paint making process and can be used as a post-additive on the painter's palette. It increases the viscosity of paint, helps paint to hold its shape and prevents settling of pigments and fillers. It is an effective rheological additive that adds thixotropic properties to paint, helps hold the shape of brushstrokes and can be used in place of wax and stearates to prevent paint from separating. It does not require any preparation to use, such as the preparation of pregels and does not require chemical activators as required by some organoclays. It can be added as a powder directly to oil or alkyd vehicles or the finished paint.

Organoclay (Bentone SD-1) is is an organic derivative of bentonite clay and used as a rheological additive. Mixes easily with oil and alkyd paints to increase viscosity, prevent pigment settling, and increase crispness of handling. Add 1–4% of total weight of the paint.
It provides viscosity increase, reduces sagging of coatings on vertical surfaces and prevents settling of pigments and fillers.
Organoclay is readily dispersible for non-polar to medium-polarity organic applications. It may be added at any point in the paint making process is using all normal paint-making equipment. This rheological additive can be incorporated in the pigment grind under high shear and under low shear. A chemical activator is not required to disperse the organoclay in conventional solvent containing paints.
It can be added to the pigment grind or by mixing rather than grinding. Its does, however, require some minimal shear (minimum tip speed 4 meters per second when a high speed mixer is used). The liquid paint to which it is to be added should well stirred as it is sifted in. Sufficient time for full activation should be allowed. The amount of time required will depend upon the amount of paint, the type and speed of mixer in use and the viscosity and solids of the system. When grinding with the pigment, it is not sensitive to high temperatures and no minimum temperature is required.
Making Paint: Add the cream-colored powder to the oil before adding the oil to the pigment. Stir it into the oil, using about 2 to 5% of the total weight of the paint. Grind the mixture with a muller on flat surface thoroughly to build viscosity and thixotropic properties. Allow the paint to rest for one or more hours before use.
Adding to Paint: Add the cream-colored powder to the paint with a palette knife or spatula, using about 2 to 5% of the total weight of the paint. It is highly recommended to grind the paint with a muller on flat surface thoroughly to build viscosity and thixotropic properties. Allow the paint to rest before use.
The manufacturer states that "tThe best rheological performance under letdown conditions is achieved when the system temperature is between 21 °C (70 °F) and 35 °C(95 °F). When used in the pigment grind, it is not sensitive to high temperatures and no minimum temperature is required.
Organoclay is made by modifying phyllosilicates (such as smectite, bentonite, etc.), which is a clay mineral originating from volcanic ash, with quaternary amines, a type of surfactant that contains a nitrogen ion. By exchanging the original interlayer cations for organic cations (typically quaternary alkylammonium ions) an lipophilic (oil loving) surface is created, consisting of covalently linked organic moieties. The lamellar structure remains analogous to the parent clay mineral.