Thixotropy agent

Mewtonian andMon-Mewtonian Materials. A Newtonian material s viscosity is shear-independent, whereas non-Newtonian materials are shear-dependent (Eig. 7). Eor most potting materials, a Newtonian material is preferred because the material is required to flow under all electronic components, but not be susceptible to shear. However, when flowable material is used for conformal coating appHcations, a non-Newtonian material with thixotropy agent added is desired since the material should flow on the electronic substrate but stop at the edge without creeping or mnover at the circuitry. 

A study was made of the comparative stabilities at various exposures of an upset stomach remedy suspension. This product consisted of a dispersion of bismuth subsalicylate and phenylsalicylate in an aqueous system. Methyl-cellulose and magnesium aluminum silicate were selected as the suspending agents, because the presence of polyvalent metallic ions precluded the use of hydrocolloids affected by these ions. In addition, it was found that methyl-cellulose contributed a demulcent effect. The viscosity, as well as the suspension characteristics of the combination of protective colloids used, was of a synergistic nature. These colloids formed a thixotropic system. The thixotropy undoubtedly aids in stabilizing this system. In order to make this product palatable and impart elegance, color and flavor were added. Sample 1 (with protective colloids) showed no separation, while sample 2 (without... 

Thixotropic agents Thixotropic agents impart thixotropy to the adhesive to control flow and increase viscosity. 

Fumed Silica. Today colloidal silica (fumed silica) is the most common thixotropic agent in epoxy resins. Fumed silica, an amorphous silicon dioxide, is a versatile, efficient additive used for flow control and thixotropy. Fumed silica has long been the dominant thixotrope employed in the adhesive and sealant industry. 

Special considerations filler porosity is important consideration in silica matting agents some silica matting agents affect thixotropy of alkyd paints... 

Other thixotroping agents include Bentones and Tixogels, of which a number of grades are available, and China clay or kaolin, usually added as a filler, but which imparts thixotropy to the formulated product. Organofunctional silanes are extremely effective... 

CAS 112945-52-5 EINECS/ELINCS 231-545-4 Uses Filler for plastics, silicone rubber, cosmetics, pharmaceuticals, direct and indirect food applies., transparent polyester resin coatings, specialty RTV systems adsorbent, anticaking agent, glidant, suspending agent for pharmaceuticals thixotropy/suspension aid for acrylic enam-... 

In order to suppress the dripping of polyolefins, thixotropy-inducing agents like bentonite may be added. 

Fumed silica is widely used in industry as an efficient thickening agent providing shear thinning and thixotropy to liquid media like adhesives, resins, paints, and inks. Various parameters control the rheological performance of fumed silica ... 

Thixotropic agent n. A chemical that imparts the property of thixotropy to a solution or suspension. 

Kaolin or china clay, like many minerals, is used much more widely outside the plastics industry than within it, especially in the paper industry but also to a lesser extent in paint, rubber and pharmaceuticals. It is currently used to improve the electrical properties of PVC wire and cable insulation. Other applications are in automotive parts and as an antiblocking agent in plastic films. It can benefit thixotropy, and calcined kaolin can improve dimensional stability. (Calcined kaolin is also competing with silica in the antiblocking agent market.) Polarite 102A from Imerys is an example of a premium kaolin product, targeted at polyamide automotive applications. 

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