Fillers general requirements

One of the disadvantages of CTBN epoxy adhesives has been their high viscosity, which limits formulation options. Recently new adducts, such as EPON 58003 and RSM-2577 from Resolution Performance Products, have been introduced that have significantly lower viscosities.28 In addition, lower concentrations of these new CTBN epoxy adducts are generally required to achieve equivalent adhesive performance. New lower-viscosity CTBN adducts have also resulted in formulations where a greater concentration of cost-reducing filler, such as calcium carbonate, can be used. 

Respirators come in two primary types air supplied or air purifying. Air supplied respirators provide the user with an external supply of clean breathing air, while air purifying respirators make use of adsorbents and fillers to remove chemical vapors and particulate from the air. Respirators are generally required where solvent or dust levels are high, where irritating odors are present, and where materials that are respiratory sensitizers are common. 

Except for the approximate 400,000 pounds (180,000 kg) of decachlorobiphenyl imported from Italy and Erance used as filler for investment casting waxes (lARC 1978), most domestic use of PCBs was restricted to nominally closed applications by 1974 (lARC 1978). The production of capacitors and transformers involved filling them with Aroclors through a small hole in the unit and then sealing the hole. While smaller capacitors contained smaller amounts, the production of large capacitors generally required at least 2-3 pounds (1 kg) of Aroclors many times that amount was required to produce the transformers. By 1976, only 5% of the transformers produced in the United States were filled with... 

RPs can be processed in different ways. The individual components (reinforcement and resin) can be put together by the processor. Although TP resins generally require no additional material, the TSs usually require the addition of different additives and fillers, such as those reviewed in Chapter 6. 

In the first, the reactivity of the filler surface to well defined probe molecules is observed. Of these, FMC is perhaps the more powerful, giving the ability to measure heat of adsorption directly and using the polymers, coupling agents or additives of interest. IGC is more instrumentally developed, but generally requires the use of model probes because of the need for them to be volatile and reversibly adsorbed. 

Filler grade - Filler uses for barite generally require high brightness, high purity, and fine particle size, usually -325 mesh or finer. Purity is typically... 

Another difference between hot and cold elastomeric SBR latices is that hot types are carried to < 90% conversion and not normally shortstopped. The cold latices are usually shortstopped at ca 60—80% conversion. Again the desired physical properties of the contained copolymer are responsible for these differences. Cold latices are used in applications where the modulus, eg, in foam, or retention of physical properties at high filler loadings, eg, in fabric backing, are required. The cold latices are generally suppHed at a higher soHds concentration than the hot series because of these uses. 

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