Acrylic resin coating systems

Uses Crosslinking agent in melamine resin coating systems, general industrial finishes, coil-coating enamels, appliance finishes, useful with alkyd, polyester, thermosetting acrylic, epoxy, and cellulose resins Properties Gardner 2 max. clear, vise, liq. limited water-sol. dens. 10.0 Ib/gal vise. (G-H) X-Z2 flash pt. > 180 F 98% NV Cymel 350 [Cytecind.j... 

Another specialty area is coil coating, which involves coating metal coils by continuous operation. Modern roller systems afford speeds of up to 200 m/min. Most coils are made of cold-rolled and surface treated steel, aluminum, or alloys of the latter with manganese or magnesium. Coating systems are based on alkyd or acrylic resins, oil-free polyester, silicone-modified polyester or acrylic resin, poly(vinylidene fluoride), or poly(vinyl fluoride). Water-reducible systems, mainly based on acrylic resins, have been developed for aluminum as well as for steel coils [21-24], Drying is carried out by continuous operation in gas- or oil-heated multichamber ovens. 

Deep shades of maroon tend to form water spots in certain binder systems, especially in media which are based on acrylic resin. More or less distinctive light spots appear on the coating. The effects that cause this phenomenon remain to be elucidated. Factors such as long-term weathering at elevated temperature, U V radiation, and the presence of demineralized water probably cause reduction and solvation effects within the coating. Products are available which are much less susceptible to these agents. Rub-out effects, especially flocculation, may also present problems in various binder systems. Special-purpose grades are therefore available which are more stable to flocculation. 

The majority of water-based UV systems are currently being used in the cabinet industry. Water-based UV coatings should be a blend of different resin systems such blends offer certain benefits. Urethane systems offer excellent clarity, hardness, and flexibility. Acrylic resins are easy to apply and offer quick water evaporation. 

Sanitary ware, including tubs, showers, combined units, basins, and toilet tank, may be made of thermoformed ABS or acrylic sheet, molded glass-fiber-reinforced polyester, or cast acrylic resins. The glass-polyester type dominates the tub/shower market. It is possible to install the units as a two-component system, assembled in place. Gel coats may be of thermoformed decorative acrylic skins. To reduce the smoke generated by fire, methyl... 

Both aqueous polymer-based systems (latex), made by emulsion or dispersion polymerization, and oil-modified alkyd resin-based systems are still in wide use [781], Table 12.2 shows the composition of a typical water-based emulsion paint. There is a wide variety of coatings, ranging from broad applicability to highly specialized, including latexes, amino resins, isocyanates, epoxy resins, acrylic resins, polyester... 

Irradiation by Ultra-Violet or Visible Light. Systems of this nature comprise materials such as acrylic resins in which a photo-sensitizer (for example, benzophenone) is incorporated. On exposure to ultra-violet radiation the photo-sensitizer dissociates into free radicals which then catalyse polymerization of the acrylic material. The reaction is controllable and takes place within a few seconds the ultra-violet radiation may be directed and focused so as to obtain cure precisely where needed. Products like these are used to retain coatings, wiring, and other components in the assembly of electronic goods. 

Conventional industrial coatings materials of the thermoset type are usually acrylic, polyester, epoxy, polyurethane or silicone resins dispersed or dissolved in organic or water/ether-alcohol coupling solvents. They are cured with gas convection or electric IR ovens. The raw materials for the polymers come from petroleum feedstocks which are processed or manufactured into a finished coating system. 

Another interesting procedure for obtaining a two-layer system involves [97] the formation of a base layer of the polymeric photoinitiator, through a spin coated film onto different substrates, followed by their immersion, under UV irradiation, into multifunctional acrylic formulations dissolved in solvents unable to remove the base layer from the substrate. By this method, a top layer of crosslinked acrylic resin is obtained, having strong adhesion to the substrate. The replacement of the polymeric photoinitiator by a low-molecular-weight analogue... 

Powder-grade PVDF is the key ingredient in the formulation of premium architectural coatings. The primary components of a PVDF-based coating system are 1) PVDF resin (typically 15-30%) 2) acrylic resin (typically 6-15%) 3) pigment (typically 10-20%i) 4) organic solvent (typically 40-65%i) and 5) other additives (typically 2-5%i), such as UV absorbers, antisettling additives, surfactants, etc. ... 

Chemical produces methylamine and its derivatives, and acrylic, polyurethane and polyester rapid cure and pressure-sensitive resins for solvent-free coating systems ... 

The acrylic resin used was Rohm and Haas Co.s QR-496 ( 4), so the exact nature of the polymer is not known. It is hydroxy functional, thus requiring an aminoplast for proper cure commercially modified hexa-methylol melamine resin was used for this purpose. During the first part of the investigation the acrylic resin was used without the melamine resin, but for final evaluation it was incorporated to give a more realistic commercial coating system. 

Acrylic Resin. The acrylic resin had excellent solubility characteristics in all nine solvents. On the basis of electrocoating experiments, sec-butyl alcohol, methyl isobutyl carbinol, and methyl isobutyl ketone were ruled out. It is not possible to coat these systems above 30-40 volts. All... 

Two solvents used in this evaluation, 2-butoxyethanol and 2-(2-butoxyethoxy) ethanol, were the most versatile. Except for the film appearance of the trimellitic alkyd, satisfactory coating systems could be made with each of the three resins. The 2-butoxyethanol has slightly lower viscosity and lower cost. On the other hand 2-(2-butoxyethoxy)-ethanol gave slightly higher rupture voltages. With the acrylic resin and... 

As mentioned earlier, UV-curable resin formulations are very attractive for fiber coating because of the rapid cross-linking rates that are achievable. Most commonly, epoxy- or urethane-acrylate resins are employed (18-22), and viscosity and cross-link density are controlled through the addition of reactive diluents. With these systems work has focused on producing low modulus, low T properties (20-22) through the incorporation of appropriate chemical constituents to enhance higher chain flexibility, for example, ether linkages. 

A second generation of phenolic dispersions, patented by J. S. Fry (33). involved the post dispersion of phenolic resins in a mixture of water and water-miscible solvents. To conform with air pollution regulations, the solvent was held to 20 volume %, or less, of the volatiles. A heat-reactive phenolic resin dispersion (34) and a phenolic-epoxy codispersion have become commercially available based on the above technology. Supplied at 40-45% solids, these products, which have a small particle size (0.75-1.0 ym), are better film formers than the earlier dispersions. Used alone or in blends with other waterborne materials, corrosion-resistant baking coatings may be formulated for coil coating primers, dip primers, spray primer-surfacers, and chemically resistant one-coat systems. Products of this type are also tackifiers for acrylic latexes, and such systems have been employed as contact, heat seal, and laminating adhesives for diverse substrates. 

Many studies have appeared dealing with the properties of crosslinked polymer systems. These include adhesion of epoxy-acrylates onto tin-plate, adhesion of isocyanate and epoxy-resin coatings, adhesion of butadiene-acrylate rubbers onto metals, glass, and ceramics, adhesion of acrylic, thiol, and polyester resins to aluminium bodies, and the mechanical and physical properties of photo-crosslinkable poly(vinyl cinnamate), vinyl-divinyl copolymers,polythiols, acrylates, epoxies, and thiols,epoxy resins, polyesters on wood, ... 

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