Coatings and Wash Primers

Some dichromate conversion coatings and wash primers designed for corrosion prevention are suitable for adhesive bonding. [Pg.493]

The largest commercial use for polyvinyl formal is as wire enamel, usually in conjunction with cresylic phenolic resin. Similar resins are used also with phenolics as structural adhesives. They are very resistant to greases and oils. Some grades have been used as can coatings and wash primers. Although they can be molded, extruded, or cast, these grades have achieved little commercial significance. [Pg.451]

Uses Corrosion inhibitor pigment for reactive coating systems and wash primers fungistat... [Pg.540]

The wash primer is a special type of vinyl coating. This material contains a poly(vinyl butyral) resin, zinc chromate, and phosphoric acid in an alcohol-water solvent. The coating is so thin it is HteraUy washed onto a freshly blasted steel surface, where it passivates the metal surface by converting it to a thin iron phosphate-chromate coating. The alcohol solvent makes it possible to apply the coating over damp surfaces. The coating forms the first coat of... [Pg.365]

The main application of poly (vinyl formal) is as a wire enamel in conjunction with a phenolic resin. For this purpose, polymers with low hydroxyl (5-6%) and acetate (9.5-13%) content are used. Similar grades are used in structural adhesive (e.g. Redux) which are also used in conjunction with phenolic resin. Poly(vinyl formal) finds some use as a can coating and with wash primers. Injection mouldings have no commercial significance since they have no features justifying their use at current commercial prices. [Pg.393]

A low acid polyvinyl butyral-based pretreatment primer ( etch or wash primer are alternative names) is usually advantageous as the first treatment of a metal-sprayed surface before painting. Up to an equal volume of spirit soluble phenolic resin is used as a diluent to the polyvinyl butyral of conventional pretreatment primers. This has an incidental, but particularly valuable effect, in reducing the free acid available to penetrate into the pores of the coating. The modified pretreatment primer is highly water resistant and this helps to avoid damage due to condensation. [Pg.431]

Welds on steelwork need special attention because of the different composition of weld metal and adjacent steelwork, the rough surface and spatter caused by welding and the presence of welding flux. The latter is often alkaline and destructive to many paints. It is necessary to clean thoroughly, preferably by reblasting for 25-50 mm each side of the weld, fare the rough metal and wash off residual flux. The cleaned surface should then be stripe coated with the primer used on the remainder of the surface. [Pg.642]

ECL has also been applied to the analysis of polymerase chain reaction (PCR) products [53,55], PCR is first used to amplify the specific genes by use of two primers, one of which is biotinylated. The double-stranded DNA is then captured on streptavidin-coated magnetic beads and washed with an alkaline solution to denature and separate the strands. The particle-bound, single-strand DNA is used to capture products hybridized with Ru-labeled complementary... [Pg.179]

Major polymer applications safety glass interlayer (automotive windshields), control of light, heat and sound in construction glass, bulletproof glass, adhesives and sealants, binders for rocket propellant, photoconductive papers, magnetic tapes, powder coating, wood sealers and primers, inks, ceramic binders, dry toners, wash primers, composite fiber binders... [Pg.681]

Chem. Analysis 80% (polyvinyl butyral) 1.5% max. (polyvinyl acetate) Uses Polyvinyl butyral for coafings and adhesives binders for inks, toners, adhesives, and structural composites wash primers and general metal or wood coatings indirect food additive Features Thermoplastic imparts adhesion, toughness, and flexibility retains clarity of coating... [Pg.137]

Uses Thixotrope for high polarity and oxygenated solv. systems such as nail lacquers, paints/coatings (nitrocellulose lacquers, sol n. vinyls, epoxies, acrylics, wash primers, inorg. zinc-rich primers, chlorinated mb-ber, unsat. polyesters)... [Pg.867]

Sathiyanarayanan, S., Syed Azim, S., and Venkatachari, G. (2009) Corrosion protection of galvanized iron by polyaniline containing wash primer coating. Prog. Org. Coat, 65,152-157. [Pg.291]

Zinc tetroxychromate, or basic zinc chromate, is commonly used in the manufacture of two-package polyvinyl butyryl (PVB) wash primers. These consist of phosphoric acid and zinc tetroxychromate dispersed in a solution of PVB in alcohol. These etch primers, as they are known, are used to passivate steel, galvanized steel, and aluminium surfaces, improving the adhesion of subsequent coatings. They tend to be low in solids and are applied at fairly low film thicknesses [23]. [Pg.41]

Aluminum. Aluminum is cleaned hy solvents and chemical solutions to remove oily soils and corrosion products. Cleaned aluminum is pretreated using chromate conversion coating and anodizing. Phosphoric acid-activated vinyl wash primers, which are also considered pretreatinents, must he applied directly to metal and not over other pretreatinents. [Pg.352]

Solvent A liquid used to dissolve or disperse the film forming constituents to regulate the desired properties. Substrate The surface in which a coating is applied. Wash primer 91% polyvinyl butyl and 9% zinc tetraoxychromate by weight in a mixture of isopropanol and butanol which is mixed with 18% PO4 in isopropanol and water just before use. [Pg.436]

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