Primers, general paint

Chem. Descrip. Amorphous hydrated siiica CAS 7631-86-9 EINECS/ELINCS 231-545-4 Uses Matting agent in soivent- and water-borne architectural paints, board, coii and can coatings (< 0.75 mii), eiectrocoat primers, general industrial coatings, water-based coatings, printing inks, radiation-cured systems (< 0.75 mii), vinyi topcoats Features Med. porosity... 

General paint coating systems are a combination of oil-type rust preventative primer and long oil alkyd resin paint or chlorinated rubber paint (intermediate and overcoats) with a total thickness of less than 150 p,m. These are applied in relatively mild atmospheres such as rural, mountain, and city. 

The pigment is the principal agent in the electrochemical control of corrosion by primers (see Section 14.3). Probably the best known anticorrosive pigment is red lead. When used in conjunction with linseed oil as the binder it gives very good primers which will perform well over relatively poorly prepared (manually abraded) steel surfaces. Present-day use of red lead (and lead pigments, generally) in paints has been drastically curtailed as a result of understandable pressure from the environmentalists. 

Zinc phosphate primer 54 38 2 h 24 h Lead and chromate-free, general purpose for steel in atmospheric exposure, can recoat conventional paint systems... 

Ba0-B203-H20, is used as a corrosion inhibitor in industrial paints and primers, a biocide in paints and plastics, and to a lesser extent as a fire retardant additive. It is generally manufactmed by reacting barium sulfate with a sodium tetraborate hydrate in water. Several other crystalhne hydrated barium borates are also known but have less industrial importance. 

The properties of the latices and the paints produced from them were evaluated by several commercial firms. Ihe latex properties varied somewhat from sample to sample but, in general, the paints produced from the latexes were comparable to those produced from high-grade commercial latexes made by conventional means. One property of the paint produced from the radiation-catalyzed latex, enamel holdout, which is one measure of the capability of a paint to serve as a primer for enamel on unpainted wood, was superior to that of paint made from conventionally produced latex. 

Soluble Polystyrene. Styrene homopolymers (generally in admixture with other binders) are used in special applications such as zinc dust primers and bronze lacquers, in paints for mineral substrates and paper, as well as in adhesives. Polystyrene and poly(a-methylstyrene) have good water resistance, low permeability, resistance to chemicals and light, and also dry quickly. Suitable solvents include aliphatic and aromatic hydrocarbons, in some cases containing ketones or esters. 

Heavy-duty coating systems generally comprise two primer coats and two topcoats, modern system sometimes consist of one primer coat and two topcoats. The total dry film thickness (DFT) of such anticorrosive paint systems is 150 - 200 pm, each layer has a minimum DFT of 40-50 pm. Due to their excellent adhesion, the first and second primers prevent corrosion of the metal surface. The pigments and extenders allow the primers to react with ions (CD and SO4") that diffuse into the film from the atmosphere. The pigmented organic film also forms a barrier against humidity that may otherwise initiate a corrosive process. 

Trailers. Trailer chassis are generally coated in the same way as truck chassis but with a two-coat system. The primer is either a one-pack alkyd paint or a two-pack epoxy paint that are cured at ambient temperature with amine adducts or isocyanates. 

Chem. Descrip. Calcium carbonate CAS 471 -34-1 EINECS/ELINCS 207439-9 Uses Filler tor interior flat paints, primers, sealers, polyester fiberglass premixes, preforms, hand lay-up gel coats, rubber automotive prods., household prods., tubing, medical prods., closures, putty, caulk, bath tub sealers, adhesives filler for NR, SR, polyvinyl plastisols, PE, coated materials, heels, soles, flooring, mats, molded and extruded goods, foam prods., footwear, sundries, SMC Features Fine-ground general-purpose... 

Uses Acrylic for fast drying two-pack systems, primer surfacers for car repair and general Industrial applies., automotive refinishinq, hlqh-qrade Industrial paints... 

Chem. Descrip. Phenolic modified alkyd (TOFAoil type) in xylene Uses Alkyd for metal/wood primers, automotive/industrial primers, aerosol finishes, aluminum paints, machine enamels, flooring finishes, marine finishes, lawnmower/toy enamels Features General purpose resin fast drying and nonlifting Properties Gardner 12 max. color dens. 8.3 Ib/gal vise. W-Y acid no. 35 50% NV... 

Uses Alkyd for air-dty, low-bake, and general-purpose stoving industrial paints, primers, enamels, hammer finishes, marine paints, coatings for toys, office furniture, drums, agric. machinery Features High adhesion, cohesion, flexibility Properties Vise. 1600 mPa s acid no. 7 (base resin) flash pt. (Abel CC) 38 C 70% NV... 

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