Coatings additives

In addition to chemical and spectral sensitizers, several other classes of chemical compounds are added to emulsions before coating. Additives are used to facihtate coating operations, eg, surfactants (qv) and viscosity enhancers to reduce spontaneous development ia unexposed regions, eg, tetraazaiadenes and mercaptotetrazoles and to reduce abrasion and permit high temperature processing, eg, aldehydes (qv). 

Eatty bisamides are used primarily to kicrease sHp, reduce blocking, and reduce static ki polymeric systems. Other specialty appHcations kiclude cosolvents or coupling agents for polyamide reskis, fillers for electrical kisulation coatings, additives for asphalt to reduce cold flow, and synthetic waxes for textile treatments (68). Bisamides have been used ki all the traditional primary amide appHcations to kicrease lubricity and have become the amide of choice because of thek better efficiency. Bisamides have the highest commercial value ki the amide market. 

Extmsion coating lines operate at speeds up to 1000 m /min and can apply 10—30 g/m of coating. Additionally, multiple layers can be extmded from one die. Multiple extmders feeding one die provide the unique capabiUty of producing layers of different resins to give superior functional properties. For example, an inexpensive resin can be used as the core of a three-ply extmdate, the outer pHes being more expensive but also much thinner than if extmded alone. 

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. 

Table 2 Preservatives found in the coatings/additives application...

L.J. Calbo, Handbook of Coatings Additives, M. Dekker, New York, NY (1987). 

Table II.I gives references for a variety of plastic, rubber and coatings additives and polymerisation aids.

Table II.l Classes of commercial plastic, mbber and coatings additives and polymerisation aids (including references to databases by trade name, chemical, function, application and manufacturer)...

R.J. Kane (ed.), Paper Coating Additives, TAPPI Press, Atlanta, GA (1995). 

Novel coating additives are also being studied as a way to ameliorate the disadvantages that have become synonymous with waterborne paints ... 

Only free enzyme conjugate will bind to the coating. Addition of an enzyme substrate results in formation of a blue color, the intensity of which is inversely proportional to the amount of -lactam in the sample. Absence of -lactams in a sample results in all of the enzyme conjugate remaining unbound and available for binding to the immobilized -lactam. Presence of -lactams results in a portion of the enzyme conjugate being bound and unavailable to bind with the immobilized -lactam. The Delvo-X-Press test uses an optical density reader to compare the optical density of a standard set at a cutoff level of 5 ppb penicillin G, with that of each sample tube in total assay time of about 10 min. 

Semiconductor Materials LCD Materials Coating Additives Performance Chemicals Curable Resins... 

Specialty Chemicals Coatings Additives Plastics Acetate Cable Rare Earths Silicas Fine Chemicals Sulfuric Acid Services... 

Compatibility with film-coating additives and the tablet being coated. 

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