Paints, conducting

These systems have not been installed to any significant extent and have now been superseded by conductive paints, conductive polymers or titanium mesh anode systems. 

For EMI shielding applications, numerous processes are used, some require conductive fillers. These applications include parts molded with conductive filler and conductive paints. Conductive fillers used in commercial applications include aluminum, silver, nickel, and copper flakes and powders, stainless steel fibers, and fibers and flakes coated by nickel and silver. Thermoplastic compounds can provide up to 65-70 dB of electromagnetic noise attenuation but obtaining values over 45 dB is difficult. Static dissipative compounds (ESD) are mostly produced with carbon black which accounts for approximately 90% of the market but many other fillers are also used. 

Mitsubishi Carbon Black . [Mitsubishi Kasei] Carbon black pigments for inks, plastics, paints conductive grades avail. 

Similar to the Types la and lb fibers, the Type Ic fibers consist of a thin, conductive metal layer electrodeposited upon a carbon base fiber (see Figure 5). Their manufacture is described by Morin(27) and by HaU and Ando(25). The paper by Hall and Ando provides a good overview of their properties and characteristics. Nickel plated exPAN carbon fiber are typical of the Type Ic fibers that are readily commercially available. General uses for Type Ic fibers are in ESI shielding, conductive adhesives and paints, conductive fabrics, and high performance electric contacts(2P). They are included in the Type 1 category because their conductivity is characteristically metallic. Thus, by this convention they appear in the Type 1 classification while the various other carbon fibers fall into the Type 2 category. 

Traditional appHcations for latices are adhesives, binders for fibers and particulate matter, protective and decorative coatings (qv), dipped goods, foam, paper coatings, backings for carpet and upholstery, modifiers for bitumens and concrete, and thread and textile modifiers. More recent appHcations include biomedical appHcations as protein immobilizers, visual detectors in immunoassays (qv), as release agents, in electronic appHcations as photoresists for circuit boards, in batteries (qv), conductive paint, copy machines, and as key components in molecular electronic devices. 

Ziac foil coated with a conductive, pressure-sensitive adhesive is used for repair of other ziac coatings or for imparting corrosion resistance at field sites. The 0.08-mm ziac tape or sheet has a 0.025-mm coaductive adhesive. The laminate is cut to size and pressed tightly to activate the adhesive. Conductive tape can be wrapped around pipe, especially around welds or connections. The corrosion resistance of this material is iatermediate between galvanized or thermally sprayed coatings and zinc-filled paints (21,50). 

Metal powder—glass powder—binder mixtures are used to apply conductive (or resistive) coatings to ceramics or metals, especially for printed circuits and electronics parts on ceramic substrates, such as multichip modules. Multiple layers of aluminum nitride [24304-00-5] AIN, or aluminay ceramic are fused with copper sheet and other metals in powdered form. The mixtures are appHed as a paste, paint, or slurry, then fired to fuse the metal and glass to the surface while burning off the binder. Copper, palladium, gold, silver, and many alloys are commonly used. 

Reaction of 1-pentanol with propionic acid provides 1-pentyl propionate [624-54-4] a new coatings solvent for automotive refinish and OEM paints, apphances, and for higher-solids systems (37). The esterification of 1-pentanol with formic acid to 1-pentyl formate [638-49-3] is conducted by concomitant removal of by-product water by a2eotropic distillation with diethyl ether (38). 

Electrostatic spraying is used in shops to coat conductive objects. It is very useful for odd-shaped objects such as wire fence, cables, and piping. An electrostatic potential of 60,000 volts on the object attracts oppositely-charged paint particles the spray can wrap around and coat the side of the object opposite to the spray gun. This technique produces very uniform finishes and has the least paint loss of the three methods. However, it is slow, requires expensive equipment, produces only thin coats, and is sensitive to wind currents. 

MiscelEneous. Small quantities of cobalt compounds are used in the production of electronic devices such as thermistors, varistors, piezoelectrics (qv), and solar collectors. Cobalt salts are useful indicators for humidity. The blue anhydrous form becomes pink (hydrated) on exposure to high humidity. Cobalt pyridine thiocyanate is a useful temperature indicating salt. A conductive paste for painting on ceramics and glass is composed of cobalt oxide (62). 

Surfaces. Essentially any electrically conductive surface can be electroplated, although special techniques may be required to make the surface electrically conductive. Many techniques ate used to metalline nonconductive surfaces. These are weU-covered ia the Hterature (3) and can range from coating with metallic-loaded paints or reduced-silver spray, to autocatalytic processes on tin—palladium activated surfaces or vapor-deposited metals. Preparation steps must be optimized and closely controlled for each substrate being electroplated. 

The introduction of rfpowered sources has extended the capability of GD-OES to non-conductors, and several rf sources of different design have become commercially available. This is of the greatest importance for surface and depth-profile analysis, because there exists a multitude of technically and industrially important non-conductive coating materials (e. g. painted coatings and glasses) which are extremely difficult to analyze by any other technique. 

If the rf source is applied to the analysis of conducting bulk samples its figures of merit are very similar to those of the dc source [4.208]. This is also shown by comparative depth-profile analyses of commercial coatings an steel [4.209, 4.210]. The capability of the rf source is, however, unsurpassed in the analysis of poorly or nonconducting materials, e.g. anodic alumina films [4.211], chemical vapor deposition (CVD)-coated tool steels [4.212], composite materials such as ceramic coated steel [4.213], coated glass surfaces [4.214], and polymer coatings [4.209, 4.215, 4.216]. These coatings are used for automotive body parts and consist of a number of distinct polymer layers on a metallic substrate. The total thickness of the paint layers is typically more than 100 pm. An example of a quantitative depth profile on prepainted metal-coated steel is shown as in Fig. 4.39. 

For asbestos removal, the provisions of the OSHA Asbestos Standard 29 CFR 1926.1101 are more protective of worker health and safety than are the more general provisions. The HASP therefore provides that the asbestos removal tasks conducted inside the building will be performed in accordance with the OSHA Asbestos Standard. After the asbestos has been removed, the lead-based paint will be removed. Again, the provisions of the OSHA Standard for lead removal are more protective of worker health and safety than are the more general provisions of 29 CFR 1910.120. Therefore, the removal of the lead-based paint inside the building will be performed in full compliance with the OSHA Lead Standard [1]. 

Metal flakes in a suspension are common. For example, aluminum paint is actually aluminum flakes suspended in paint. Upon application, the flakes orient themselves parallel to the surface and give very good coverage. Similarly, silver flakes can be applied to give good electrical conductivity. 

Impedance spectroscopy This technique is essentially the extension of polarization resistance measurements into low-conductivity environments, including those listed above. The technique can also be used to monitor atmospheric corrosion, corrosion under thin films of condensed liquid and the breakdown of protective paint coatings. Additionally, the method provides mechanistic data concerning the corrosion processes, which are taking place. 

Carbonaceous materials graphite, carbon, graphite chips, coke breeze, conductive polymer, conductive paint. 

Conductive paints (resins) have recently been used for the cathodic protection of steel reinforcing bars in concrete, but they are always used in conjunction with a primary anode material, e.g. platinised-niobium or platinised-titanium wire or a conductive polymer rod. 

Brown and Fessler have conducted a laboratory evaluation of conductive mastics that can be brushed or sprayed onto the concrete surface to achieve the necessary thickness. However, the most extensive study on conductive paints for cathodic protection purposes has been undertaken by the Federal Highway AuthorityA total of nine commercially available resins were evaluated in this work. It was shown that neither thermal cycling, freeze thawing nor the application of cathodic protection currents... 

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