COATINGS RESINS

Hexamethylolmelamine can further condense in the presence of an acid catalyst ether linkages can also form (see Urea Eormaldehyde ). A wide variety of resins can be obtained by careful selection of pH, reaction temperature, reactant ratio, amino monomer, and extent of condensation. Eiquid coating resins are prepared by reacting methanol or butanol with the initial methylolated products. These can be used to produce hard, solvent-resistant coatings by heating with a variety of hydroxy, carboxyl, and amide functional polymers to produce a cross-linked film. 

Liquid coating resins are prepared by reacting methanol or butanol with the initial hydroxyme-thylureas. Ether exchange reactions between the amino resin and the reactive sites on the polymer produce a cross-linked film. 

Fulk Storage and Handling of Acy hid Coating Resins, C-186, Rohm and Haas Co., Philadelphia, Pa. 

Syntactic Cellular Polymers. Syntactic cellular polymer is produced by dispersing rigid, foamed, microscopic particles in a fluid polymer and then stabilizing the system. The particles are generally spheres or microhalloons of phenoHc resin, urea—formaldehyde resin, glass, or siUca, ranging 30—120 lm dia. Commercial microhalloons have densities of approximately 144 kg/m (9 lbs/fT). The fluid polymers used are the usual coating resins, eg, epoxy resin, polyesters, and urea—formaldehyde resin. 

Heat-reactive resins are more compatible than oil-soluble resins with other polar-coating resins, such as amino, epoxy, and poly(vinyl butyral). They are used in interior-can and dmm linings, metal primers, and pipe coatings. The coatings have excellent resistance to solvents, acids, and salts. They can be used over a wide range of temperatures, up to 370°C for short periods of dry heat, and continuously at 150°C. Strong alkaUes should be avoided. 

Catalysts. The alkanolamines continue to find use as blocked catalysts for textile resins, coatings resins, adhesives, etc. Of particular utifity in curing durable-press textiles is AMP-HCl. Other salts, such as those of the benzoin tosylate or A-toluenesulfonic acid, find utifity in melamine- or urea-based coatings (18) (see Amino resins and plastics). 

Although blending with other coating resins provides a variety of ways to improve the performance of alkyds, or of the other resins, chemically combining the desired modifier into the alkyd stmcture eliminates compatibiUty problems and gives a more uniform product. Several such chemical modifications of the alkyd resins have gained commercial importance. 

Trimethylolpropane inNlkyd Coating Resins, Celanese Chemical Co., New York, 1961, p. 4. 

New teipolymers of vinyl acetate with ethylene and carbon monoxide have been prepared and their uses as additives to improve the curing and flexibihty of coating resins, eg, nitrocellulose, asphalt, phenoHcs, and polystyrene, have been described (130—132). Vinyl acetate and vinyUdene cyanide form highly alternating copolymers. 

Toxicological Studies of Uralac Powder Coating Resin andPowders, Scado B. V., ZwoUe, The Netherlands, 1979. 

Other Coatings Resins. A wide variety of other resin types are used in coatings. PhenoHc resins, ie, resins based on reaction of phenols and formaldehyde, have been used in coatings for many years. Use has been declining but there are stUl significant appHcations, particularly with epoxy resins in interior can coatings. 

This lelationship has been shown to hold for a wide variety of coating resins and resin solutions over a wide range of concentrations. A simplification of equation 3 where T is the reference temperature is given in equation 2, which assumes that the viscosity at T is 10 Pa-s. 

The most important coating appHcation for the nonreactive polyamide resins is in producing thixotropy. Typical coating resins such as alkyds, modified alkyds, natural and synthetic ester oils, varnishes, and natural vegetable oils can be made thixotropic by the addition of dimer acid-based polyamide resins (see Alkyd resins). Specialty high performance coating appHcations often requite the properties imparted by dimer acid components. 

Thin coatings consist of paints and varnishes, which are applied as liquids or powdered resin with a thickness of about 0.5 mm [e.g., epoxy resin (EP) [2]]. Typical thick coatings are bituminous materials [3] and polyolefins [e.g., polyethylene (PE) [4]], thick coating resin combinations [e.g., EP tar and polyurethane (PUR) tar [2]] as well as heat-shrinkable sleeves and tape systems [5]. 

The ease with which acrylic monomers may polymerise with each other and with other monomers has led to a host of compositions, frequently of undisclosed nature, being offered for use as moulding materials, casting resins, coating resins, finishing agents and in other applications. 

Polyesters are eneountered in many forms. They are important as laminating resins, moulding compositions, fibres, films, surface coating resins, rubbers and plasticisers. The common factor in these widely different materials is that they all contain a number of ester linkages in the main chain. (There are also a number of polymers such as poly(vinyl acetate) which contain a number of ester groups in side chains but these are not generally considered within the term polyester resins.)... 

These comprise a large group because almost any acid can be reacted with almost any alcohol to produce an ester which might be suitable as a coating resin. The distinction between an alkyd and a polyester is that the former contains monobasic acids usually derived from vegetable oils such as linseed, soyabean or coconut while the latter do not. 

Figure 3 Gradient separation of anions using suppressed conductivity detection. Column 0.4 x 15 cm AS5A, 5 p latex-coated resin (Dionex). Eluent 750 pM NaOH, 0-5 min., then to 85 mM NaOH in 30 min. Flow 1 ml/min. 1 fluoride, 2 a-hydrox-ybutyrate, 3 acetate, 4 glycolate, 5 butyrate, 6 gluconate, 7 a-hydroxyvalerate, 8 formate, 9 valerate, 10 pyruvate, 11 monochloroacetate, 12 bromate, 13 chloride, 14 galacturonate, 15 nitrite, 16 glucuronate, 17 dichloroacetate, 18 trifluoroacetate, 19 phosphite, 20 selenite, 21 bromide, 22 nitrate, 23 sulfate, 24 oxalate, 25 selenate, 26 a-ketoglutarate, 27 fumarate, 28 phthalate, 29 oxalacetate, 30 phosphate, 31 arsenate, 32 chromate, 33 citrate, 34 isocitrate, 35 ds-aconitate, 36 trans-aconitate. (Reproduced with permission of Elsevier Science from Rocklin, R. D., Pohl, C. A., and Schibler, J. A., /. Chromatogr., 411, 107, 1987.)...

Hydrogen cyanide is an important raw material used in the production of methyl methacrylate and is widely used for Lucite, Plexiglas molding, and extrusion powders as well as coating resins. It is used widely in the agricultural sector to fumigate orchards and tree crops. 

Used industrially in the manufacture of pharmaceuticals, textile chemicals, adhesives, binders, petroleum refining chemicals, fuels, lubricants, coating resins, varnishes, polymerizations, lacquers, agricultural chemicals, cosmetics, ion exchange resins, photographic chemicals, surfactants used in the paper industry and as a flocculation aid. 

Eventually, the final criterion, i.e. authorization and access to relevant data, led to the selection of three cases in different chemical companies using batch processes and located in The Netherlands. For reasons of confidentiality the names of these companies cannot be revealed, therefore they are named company A, B and C. Their real names are known to the author. These companies produce coating resins, active pharmaceutical ingredients and plastic granules respectively. By selecting these three... 

Figure 39 Primary process of coating resins at company A.

Aminoquinolines, 21 185, 199 Amino resins, 16 409. See also Amino resins and plastics coating resins, 7 96-98 formaldehyde in, 12 121 Amino resins and plastics, 2 618-652 chemistry of resin formation,... 

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