Metal moisture resistant coatings

Chen, G., Broad, R., Valentine, R.W., and Mannix, G.S. (2001) Ethylene-vinyl acetate copolymer as moisture resistant coating for metal fuels in pyrotechnic compositions, US Patent 6,174,391 Chem. Abstr., 134 (7), 88437s. 

Figure 4 shows the insulative ability of the above formulation. Three coats were applied over a primer to a total dry film thickness of 20 mils, allowing 24 hours dry time between coats. This graph indicates complete failure in 8 minutes. When subjected to other tests the coating lacked adhesion to metal, moisture resistance, and flexibility. After, puffing, the coating disintegrated under vibration. 

In pigmented coatings, phenolic varnishes find use as vehicles for porch and deck paints where moisture and abrasion resistance are of utmost importance. Their moisture resistance and good metal adhesion make them useful vehicles for metal primers. In concrete paints they outperform most other oil-containing vehicles due to their better alkali resistance. 

Uses Intermediate producing paints, coatings, printing inks, textiles, metals, plastic films and parts with low surf, energy, chem. and moisture resist., oil/grease resist., low ref. index, and surf, lubricity Properties Pale to tan solid sol. in acetone, isobutyl alcohol, MEK si. sol. in trichloroethylene m.w. 464 sp.gr. 1.6 (90 C) vise. 7 cps (80 C) thickening pt. 65-70 C b.p. 102-175 C (50 mm) 70.8% F Precaution Self-extinguishing Zonyl BA-L [DuPont]... 

Natural rubber latex Excellent tack, good strength. Surface can be tack free and yet bond to similarly coated surface. Poor aging and ultraviolet (UV) resistance. Good moisture resistance. Felt, fabric, paper, metal, elastomers Medium... 

Fine metal particles coated with PT are protected from oxidation and have improved handling properties [820]. Electrical conductors with good heat and moisture resistance (no discoloration) contain copper powder and 0.5% powder [821]. The electrochemical oxidation of hydrogen, formic acid, and methanol is possible on an active electrode with a small amount of platinum dispersed into a pyrrole/bithiophene copolymer as matrix [822] or on Pt-Sn catalysts electrodeposited on a PMT [823]. The reduction of tetracyanoquino-dimethane and chloranil at a PMT coated glassy carbon electrode is possible [824]. CO2 molecules can be converted to salicylic add derivatives by photoirradiation in the presence of phenol derivatives and PHT in ethanol. PHT acts as a photocatalyst on irradiation with visible light, and the luminescence is quenched by both CO2 gas and phenol molecules (cf. Sect. 3.5) [367]. 

Uses Surfactant for paints, coatings, printing inks, textiles, metals, plastic Aims and parts with low surf, energy, chem. and moisture resist., oil/grease resist., low ref. index, and surf, lubricity... 

Bromine reacts with essentially all metals, except tantalum and niobium, although elevated temperatures are sometimes required, eg, soHd sodium does not react with dry bromine but sodium vapor reacts vigorously. Metals such as lead, magnesium, nickel, and silver react with bromine to form a surface coat of bromide that resists further attack. This protective coating allows lead and nickel to be used as linings in bromine containers. Metals tend to be corroded by bromine faster in the presence of moisture than without, probably because of the formation of hydrobromic and hypobromous acids. 

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