Paste formulation, typical

Table 12.27 Typical print paste formulation for the application of liquid jaggery as a reducing system for sulphur dyes [211]...

The most common derivative, N-methyl cocoyl taurine has limited solubility and is commercially available as a 30% paste. Formulators should be aware that the figure is typically a solid content, with the surfactant content being 25%, the balance of solids being mainly salt. 

Ohmic resistance and capacitance The individual types of GCP-, CNTP (carbon nanotube paste)-, and CIL-mixtures exhibit slightly higher resistance compared to C/MO and C/SO formulations - typically within 50 - 200 Q [59, 60] - despite their more compact texture and the fact that some sources quote opposite trend in pastes with ILs [72,73]. However, the presence of ILs amplifies the capacitance signal, which can be beneficial but problematic at the same time [66]. 

The viscosity of the pastes is typically within the range of 25-200 Pa-sec. The amount and type of organic medium used is determined mainly by the final desired formulation viscosity and print thickness. 

In the paste type, the paste is dispensed into the zine ean. The preformed bobbin (with the carbon rod) is inserted, pushing the paste up the ean walls between the zine and the bobbin by displacement. After a short time, the paste sets or gels. Some paste formulations need to be stored at low temperatures in two parts. Tbe parts are then mixed they must be used immediately as they can gel at room temperature. Other paste formulations need elevated temperatures (60°C to 96°C) to gel. The gelatinization time and temperature depend upon the concentration of the electrolyte constituents. A typical paste electrolyte uses zine chloride, ammonium chloride, water, and starch and/or flour as the gelling agent. 

PVC resin applicability is defined mainly by particle size and molecular weight. Small-particle PVC made by emulsion or dispersion polymerization is typically compounded into a liquid or paste formulation and spread coated, sprayed, or molded by a number of techniques. Large-particle PVC made by suspension or mass polymerization is typically extruded, calendered, or injection molded. 

Short, soft, nonstringy adhesives formulated from heavy bodied starches or dextrins are called pastes. A typical formulation for library paste is to cook a mixture of 45% low-soluble white dextrin, 5% com starch, 5% glycerol, and 45% water. 

Typically, soHd stabilizers utilize natural saturated fatty acid ligands with chain lengths of Cg—C g. Ziac stearate [557-05-1/, ziac neodecanoate [27253-29-8] calcium stearate [1592-23-0] barium stearate [6865-35-6] and cadmium laurate [2605-44-9] are some examples. To complete the package, the soHd products also contain other soHd additives such as polyols, antioxidants, and lubricants. Liquid stabilizers can make use of metal soaps of oleic acid, tall oil acids, 2-ethyl-hexanoic acid, octylphenol, and nonylphenol. Barium bis(nonylphenate) [41157-58-8] ziac 2-ethyIhexanoate [136-53-8], cadmium 2-ethyIhexanoate [2420-98-6], and overbased barium tallate [68855-79-8] are normally used ia the Hquid formulations along with solubilizers such as plasticizers, phosphites, and/or epoxidized oils. The majority of the Hquid barium—cadmium formulations rely on barium nonylphenate as the source of that metal. There are even some mixed metal stabilizers suppHed as pastes. The U.S. FDA approved calcium—zinc stabilizers are good examples because they contain a mixture of calcium stearate and ziac stearate suspended ia epoxidized soya oil. Table 4 shows examples of typical mixed metal stabilizers. 

Economics. As with the alkyl tin stabilizers, the market pricing of the mixed metal stabilizers tend to be directed by the particular appHcation. The calcium—zinc and barium—cadmium packages are typically used at 2.0—4.0 parts per hundred of PVC resin (phr) in the formulation. These completely formulated products are sold for 2.50— 4.40/kg for the Hquid products and 3.20— 6.50/kg for the soHds and pastes. The higher efficiency products aimed at rigid appHcations tend toward the higher end of the cost range. 

As pharmaceutical scientists gain experience and tackle the primary challenges of developing stable parenteral formulations of proteins, the horizons continue to expand and novel delivery systems and alternative routes of administration are being sought. The interest in protein drug delivery is reflected by the wealth of literature that covers this topic [150-154]. Typically, protein therapeutics are prepared as sterile products for parenteral administration, but in the past several years, there has been increased interest in pulmonary, oral, transdermal, and controlled-release injectable formulations and many advances have been made. Some of the more promising recent developments are summarized in this section. 

Certain vegetable and animal fats have been used as dampproofers and again emulsions or pastes are preferred and typical formulations are given in Table 4.3 [10]. The fat can be white grease, tallow or soya bean oil and although they all produce hydrophobic concrete, different effects on compressive strength are obtained. 

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