Bentone 34 organically modified bentonite clay Elementis Rheology Modifiers / Thickeners >> Organoclay >> Bentonite Acrylics/ Acrylates Epoxy (EP) Aminoplaste & Phenoplastes (UF, MUF...) Polyesters ADHESIVE SEALANT rheological additive for low to intermediate polarity organic systems BENTONE 34 is an organic derivative of a special smectite. This rheological additive is designed for low to intermediate polarity organic systems. Adhesives Automotive finishes Buffing compounds Finishes for household appliances High-build systems Industrial finishes Plastisols Putty and caulking compounds Refinishes for household appliances Underbody sealants and sound-absorbing compounds Wood preservatives and finishing systems Alkyd no hard pigment settling, no sag, no syneresis in thixotropic paints, no flooding, prevents excessive penetration Bitumen good thixotropy, no melt, no flow at elevated temperatures, no embrittlement in cold water Chlorinated Rubber Cyclized Rubber no pigment or filler settling, no stringing of the paint, good chemical stability of the coating due to homogeneous surface and higher thickness Epoxy Ester no pigment settling or sag of the paint Polyacrylic no film cracking, higher film thickness are possible Incorporation General Incorporation of BENTONE 34 in organic systems, e. g. paints, requires high shear dispersion equipment and the addition of a chemical (polar) activator. BENTONE 34 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 34: 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 BENTON E 34 as a dry powder for insitu gelation: No masterbatching process step is required with this method. The BENTONE 34 powder is added directly to the resin (diluted if need be) and is dispersed in it for 5min. After this) the pigments are added and dispersed. Then the chemical activator is added. If plastic flow of the mill base is desired, the activator can be added before the pigment. If a wetting agent is to be used, it should be added after the chemical activator 2) Addition of BENTONE 34 as a pregel: The solvent is charged to the mixing tank. BENTONE34 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 34. Suitable dispersion equipment High speed disc impellers (Cowlers Dissolver), Ultra-Turrax, pearl-, sand-, ball- and three-roll mills. Chemical (polar) activators are recommended to ensure full activation, i. e. optimum efficiency of BENTONE 34. Recommended use level of BENTONE 34 The level depends on the system in which BENTONE 34 is to be used. For house paints and industrial paints typical levels are between 0.2 and 0.5 % (dry) BENTONE 34 based on total system weight. For primers slightly higher quantities are required (0.5 -–1 % dry BENTONE 34). In aqueous systems between 0.2 and 0.3 % BENTONE 34 (dry) are used. Summary of Toxicity Data This summary is provided as an overview of more detailed toxicity test results on BENTONE 34. Comprehensive reports detailing the procedure and results of these tests are available upon request. Acute Oral Toxicity in Rats BENTONE 34 was too innocuous to permit the intragastric administration of a dose large enough to establish an LD50. Primary Skin Irritation in Rabbits Using the procedure of Draize (J. Pharm. and Exptl. Therap., 82, 377 [1944]), BENTONE 34 was inert when applied to the intact or abraded skin of rabbits. Primary Eye Irritation in Rabbits Using the procedure of Draize (J. Pharm. and Exptl. Therap., 82, 377 [1944]), BENTONE 34 caused at most only a temporary mild irritation as might be expected from any foreign body. Allergenicity (conducted with Guinea Pigs) BENTONE 34 additive is non-allergic to guinea pigs. Subacute Oral Toxicity with Rats A 12-week feeding study at the dietary levels as high as 25 % gave no indication of a toxic reaction. Chronic Skin Toxicity Study with Rabbits Experiments were conducted involving chronic exposure of the skin of rabbits to BENTONE 34 during periods of at least 6 hours or more daily for 65 consecutive weekdays. No evidence of a toxic reaction was found. Organic derivative of a special smectite rheological additive for low to intermediate polarity organic adhesives, sealants and caulks.