Primer coatings, automotive

Our electrochemical work differed drastically from the Groseclose work in that polymer coated metal samples were employed. Furthermore, we found that coatings can have corrosion resistance when their rest potentials are either more noble (B210/NVP) or less noble (B210/GBL) than the uncoated substrate. Leidheiser (22,23) examin zinc phosphate pretreated panels with automotive primer after 10 days exposure to the salt spray. The start and finish rest potentials of the samples with good paint performance were consistently more negative than those samples with poor paint performance ... 

Salt spray test. The model coatings of Table I are of the high solid type used in automotive top coats. Their primary function is not corrosion protection since this is first of all a matter of phosphate layer, electrocoat and/or primer. However, the topcoats may contribute to corrosion protection by their barrier function for water, oxygen and salts. Therefore their permeability is important as one of the factors in the corrosion protection by the total coating system. We feel that a salt spray test of the model coatings directly applied to a steel surface is of little relevance for their corrosion protection performance in a real system. 

Automotive primers and primer surfaces Coatings for domestic electrical appliances... 

Inhibitive Primers. The traditional primers are red lead and linseed oil, alkyd resins and zinc potassium chromate, proprietary epoxy, alkyd, urethane and latex systems with modified phosphate, borate and molybdate pigments. Chromate-based pigments, although in use in aircraft coatings, automotive primers and coil coating primers, are subject to environmental concern on the toxicity of hexavalent chromium which is likely to result in their replacement by innocuous products. 

Georgia. VOC emissions are limited (lb/gal) by industry and coatings used automotive— primers, 1.2 if dipped and 2.8 if sprayed, topcoat, 2.8, and repair, 4.8 metal furniture, 3.0 appliance, 2.8 and miscellaneous metal-performance coatings, 3.5, high-performance coatings, 6.2, clear-coat, 4.3, and all others, 3.0 coil coating, 2.6. 

The electrolytic deposition of a coating that is known as E-coat provides an excellent corrosion protection as evidenced by automotive coating. Today nearly all automobiles are corrosion protected by applying the cathodic E-coat, in which the steel body of a car is used as the cathode of the electrolytic deposition of a primer coat, on the surface of zinc phosphated steel. It is quite logical to consider that if an E-coat is applied to a chromate conversion-coated aluminum alloy surface, a significant improvement of the corrosion protection of aluminum alloys could be realized because such an attempt represents the combination of the two best components, i.e., chromate conversion coating and E-coat. We could find the best example that demonstrates the need of SAIE in such attempts. 

Polyester resins possess premium performance properties such as exterior durability, gloss, flexibility hardness, color stability, and versatility of cure. Polyesters are used in product finishes for household appliances, food and beverage containers, aircraft and equipment, automotive primers and bake coats, metal furniture, and fixtures. For example, water-soluble saturated polyesters are used in industrial baking paints, and in combination with melamine resin. Polyesters can be formulated in high solids and waterborne formulations to meet the requirements for the low VOC coatings being mandated by the EPA. 

The majority of the currently used coating systems is based on copolymers prepared from epoxy resins, polyfunctional amines, and partially blocked isocyanates (84-87). The resins are generally solubilized by the formation of cationic derivatives of amines by aminolysls of the carbamate in the partially blocked isocyanate. The principal applications of these cationic electrocoating systems are as automotive primers, in appliances, as primers and one-coat system.s, and in various other industrial applications. The main... 

MAJOR APPLICATIONS Protective coatings (for appliance, automotive primers, pipes, etc.). Encapsulation of electrical and electronic devices. Adhesives. Bonding materials for dental uses. Replacement of welding and riveting in aircraft and automobiles. In composites for materials in space industry, printed circuitry, pressure vessels and pipes. Construction uses such as flooring, paving, and airport runway repair. 

Uses Defoamer for water-reducible emulsion and latex systems, high gloss architectural paints, wood preservative stains, aq. flexographic inks, primers, acid catalyzed systems, automotive basecoats, coating colors (folding boxboard), wastewater treatment Properties Lt. yel. si. vise, translucent liq. sol. in butanol, glycol ethers, ethoxypropanol, hexanol, isobutanol, IPA, methoxypropanol, MEK, min. spirits, xylene partly sol. in acetone, ethanol dens. 1.01 g/ml (20 C) flash pt. > 200 C pH = 7.0 (2% in Dl water) nonionic 100% act. 

Chem. Descrip. Polyester PU disp. (41%) in water/N-methyl pyrrolidone, neutralized with dimethyl ethanolamine Uses Urethane for sfoving industrial coatings, stoving automotive primer surfacers and two-pack PU primers and top coats for plastics Properties = 50 nm mean particle size sol. in water partly sol. in glycol ethers, alcohols dens. = 1.1 g/ml (20 C) vise. 1000 0500 mPa-s-(23... 

Uses Leveling agenf, gloss aid, anficrafering agenf for aq. sysfems, aq. air-dried and baked indusfrial coatings, automotive fopcoafs, automotive primer surfacers, inks... 

Chem. Descrip. Branched sat. polyester resin in xylene Uses Polyester for solv.-based coatings, industrial coatings, bicycle and motor bike coatings, metallic base coats, primer surfacers, automotive accessory coatings... 

Uses Hardener, flexibilizer, gloss aid, flow aid in metal deco, automotive primers and topcoats, and general industrial coatings, high-solids coatings... 

Uses Flexibilizer in metal decorative, automotive primers and topcoats, oveq)rint varnishes, aerospace coatings, and prepolymer synthesis Features Highest reactivity exc. adhesion to substrates fast cure Prr rerties Gardner < 1 color It. straw liq. sol. in alcohols, esters, ketones, xylene partly sol. in min. spirits low m.w. sp.gr. 1.12 dens. 9.3 Ib/gal vise. 10,000 cps acid no. 0.1 hyd. no. 230 100% act. polyester polyol 0.02% moisture K-Flex UD-320 [King Ind.]... 

Uses Polyol for thermoset water-reducible coatings, dispersions and emulsions crosslinked with melamines or aminoplast resins, in automotive primers, container coatings, and general industrial uses Properties Vise, liq. sol. In polar org. soivs. and water insol. in aliphatic and aromatic hydrocarbons sp.gr. 1.19 g/cc vise. 11,000 cps hyd. no. 330 flash pt. (CC) > 200 F 100% act. 

Uses Butylated benzoguanamine-fonnaldehyde in combination with all, epoxide, and oil-fiee polyester resins for high performance baking enamels for appliances, can coatings, automotive primers Fealwes Unplasticized low vise. high reactivity, flexibility Properties Gardner < 1 color dens. = 1.01 g/ml (20 C) dynamic vise. 

Uses PVC plastisol adhesion promoter for automotive underbody coatings and anti-chip primers adhesion promoterforelectrodeposilion primers used in mfg. of automobiles, trucks, and buses Features 130 C cure high tens. str. 

Uses Crosslinking agent for coating systems incl. automotive primers/... 

Chem. Descrip. Antimony-doped tin oxide coated onto inert core (mica) Uses Electroconductive additive in coatings and plastics for ESD protection in electronic component pkg., floor/wall coatings, plastics, laminates electrostatic painting (automotive primers) dielec, film and paper toners... 

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