Bentone 27 trialkylaryl ammonium hectorite Elementis Rheology Modifiers / Thickeners >> Organoclay >> Hectocrite Acrylics/ Acrylates Vegetable based Epoxy (EP) Polyesters Silicones (Si) PU - Prepolymers Polyvinyl acetate emulsions & derivatives (PVAc…) SEALANT ADHESIVE >> Hot-melt >> Pressure sensitive (HMPSA) ADHESIVE >> Solvent based BENTONE 27 rheological additive is an organic derivative of a special smectite. It is designed for moderate to high-polarity organic systems and for synthetic binders. Adhesives and mastic compounds Industrial finishes Plastisols, organosols Epoxy/Coal Tar no sag of high build coats, no excessive penetration of the composition into the substrate, no flooding Nitro-cellulose combinations increased viscosity, good shelf life, no sag, higher film thickness Polyacrylic no cracking of paint film, increased film thickness Polyester increased film thickness and film stability, unpigmented top coats of good clarity Polyurethane increased film thickness, no hard pigment settling, no sag Polyvinyl increased film thickness, no settling, no sag Incorporation of BENTONE 27 in organic systems, e.g. paints, requires high shear dispersion equipment and the addition of a chemical activator. BENTONE 27 is activated in two steps: 1. Dispersion (mechanical breakdown of agglomerates) 2. Gelation (development of the gel structure) There are three basic ways to incorporate BENTONE 27: 1. as a dry powder for in-situ gelation 2. as a pregel of commonly used concentration (5-10% by weight) 3. as a pregel of higher concentration (10-15% by weight) adjusted to lower viscosity by addition of a wetting agent 1. Addition of BENTONE 27 as a dry powder for in-situ gelation: No masterbatching process step is required with this method. The BENTONE 27 powder is added directly to the resin (diluted if need be) and is dispersed in it for 5 min. After this, the pigments are added and dispersed. Then the chemical activator is added. If plastic flow of the mill base is desired, the chemical activator can be added before the pigment. If a wetting agent is to be used, it should be added after the chemical activator and prior to the pigment dispersion. 2. Addition of BENTONE 27 as a pregel: The solvent is charged to the mixing tank. BENTONE 27 powder is added and dispersed at high shear force. Then a chemical activator (most suitably methanol or propylene carbonate, see below) is introduced for gelation. For incorporation (e.g. into a paint), begin with the binder solution and stir the pregel into it. Add the pigments and disperse. 3. Addition as a pregel containing surfactant: This method is recommended when a pregel of high concentration is required or for postcorrection of the flow properties of a paint. This pregel is prepared in the same way as described under 2. It is advisable to add the surfactant to the solvent prior to introducing and dispersing BENTONE 27. For more details see Rheology Handbook. Suitable dispersion equipment High speed disc impellers (Cowles Dissolver), Ultra-Turrax, pearl-, sand-, ball- and three-roll mills. Recommended quantities of BENTONE 27 The level depends on the system in which BENTONE 27 is to be used. In paints of intermediate or high polarity, typical levels range between 0.2 and 1.0% BENTONE 27 (dry) based on total system weight. In synthetic resins (epoxy, polyester), quantities to be added are between 0.5 and 1.0 %. Summary of Toxicity Data This summary is provided as an overview of more detailed toxicity test results on BENTONE 27. Comprehensive reports detailing the procedure and results of these tests are available upon request. Acute Oral Toxicity (Rats) BENTONE 27 has an acute oral LD50 greater than 20.0 g/kg. Primary Skin Irritation (Rabbits) BENTONE 27 is not a primary skin irritant as defined by 16-CFR Hazardous Substances Act, Section 1500.41. Eye Irritation (Rabbits) BENTONE 27 is not an ocular irritant as defined by 16-CFR Hazardous Substances Act, Section 1500.42. Organic derivative of a special smectite rheological additive for moderate to high-polarity organic adhesives and sealants. Use level: 0.5 and 1.0 % in synthetic resins (epoxy, polyester).