October 2014 AROLON® 6473 Product Code: 91787-00 Acrylic Polyol DESCRIPTION ® AROLON 6473 is an acrylic polyol resin designed for use in high performance, two component polyurethane ® ® coatings. AROLON 6473 is a non-HAP’s and higher solids version of AROLON 6472. APPLICATIONS    High performance clear coats & pigmented topcoats Aerospace coatings Industrial maintenance coatings   Automotive and transportation finishes (railcar, off-road equipment) Automotive refinish     Capable of 420 g/l VOC in clears Fast dry Excellent scratch resistance Excellent buffability FEATURES     Non-HAP’s Outstanding UV durability Excellent chemical resistance Excellent flexibility & impact resistance TYPICAL PROPERTIES Appearance Percent Solids, Weight Percent Solids, Volume Viscosity, cps at 25°C (Brookfield) Gardner Color Pounds per Gallon, Solution Flash Point, °F (SFCC) Hydroxyl Value, Solids Hydroxyl Equivalent Weight, Solids Hydroxyl Equivalent Weight, Solution Solvent Clear liquid 72 67 5000 <1 8.64 81 172 326 453 n-Butyl Acetate STORAGE Store in typical warehouse conditions, 40-90F, to ensure a useful shelf life of at least one year. SAFETY ® Read the AROLON 6473 Material Safety Data Sheet before handling, storing or using this product. 919-990-7500 ● 800-448-3482● P.O. Box 13582 Research Triangle Park, NC USA 27709 ●1035 Swabia Court, Durham, NC USA 27703 ● www.reichhold.com SUGGESTED FORMULATION ® AROLON 6473 Clear Topcoat for Optimum Chemical Resistance Formula Number 4493-50C (no UVA / HALS light stabilizers) Component A: Raw Material ® AROLON 6473 Methyl n-Amyl Ketone 10% CAB-381-0.1 in MAK 1% Dabco T-12 in MAK 2,4-Pentanedione TOTAL Component A #/100 314.49 154.13 8.13 2.81 10.77 490.33 Gal/100 36.40 22.67 1.17 0.41 1.33 61.98 Component B: Raw Material Tolonate HDT-LV Methyl n-Amyl Ketone TOTAL Component B #/100 241.51 87.44 328.95 Gal/100 25.16 12.86 38.02 819.28 100.00 TOTAL Component A+B (1) (2) (3) (4) Analysis: NCO / OH * NCO Equivalents OH Equivalents VOC, Pounds per Gallon VOC, Grams per Liter Weight per Gallon Percent Solids, Weight Percent Solids, Volume % Dabco T-12 Catalyst on Resin Solids % 2,4-Pentanedione on Resin Solids 1.90 1.32 0.69 3.51 420.00 8.19 57.22 49.55 0.006 2.30 (5) Suppliers: (1) Reichhold, Inc. (2) Eastman (3) Air Products (4) (5) Sigma-Aldrich Vencorex * The NCO / OH ratio can be lowered if resistance to harsh chemicals is not a performance requirement. TYPICAL PERFORMANCE DATA ® AROLON 6473 Clear Topcoat Performance Formula Number 4493-50C (no UVA / HALS light stabilizers) Gloss, 7-day Cure, Over White Basecoat 60 Degree 20 Degree Gardner Circular Dry Time, 3 Wet Mils, Hours Set-to-touch Dry-hard Dry-through Pot Life, Viscosity, #2 Zahn Cup, Seconds Initial 1 Hour 2 Hour 3 Hour 4 Hour Conical Mandrel Chemical Resistance Durability 94 88 1.25 1.90 2.40 23.94 25.41 29.28 32.78 36.21 Pass Excellent Excellent For more information regarding tin catalysts and cure rates, please see the ACCELERATORS section of our FORMULATION GUIDELINES. ® AROLON 6473 PAGE 2 OF 5 DURABILITY DATA Weatherometer QUV-A340 QUV-B313 ® AROLON 6473 PAGE 3 OF 5 FORMULATION GUIDELINES ISOCYANATE TO HYDROXYL RATIO (NCO / OH) The ratio of NCO / OH used is very important in polyisocyanate / polyol coatings (polyurethanes) to maximize performance properties. Typically a 10% stoichiometric excess of isocyanate is recommended due to the isocyanate reacting with water from solvent, pigment, or air, and forming urea linkages. NCO / OH ratios greater than 1.1 / 1.0 provide for increased chemical resistance while lower levels offer better economics at lower performance. ACCELERATORS It sometimes becomes necessary to speed up the cure of two component urethane coatings. This can be especially true in high solids systems where dry time can be quite sluggish. These accelerators will reduce the pot life and should only be used as needed. Pot life and curing time require careful formulation to achieve a good balance of performance and application properties. There are several types of accelerators available, but the most common are tin and amine compounds. Organotin catalysts are preferred over amine catalysts, since they don’t affect pot life as drastically. The most commonly used organotin compound is dibutyltin dilaurate. Usage levels are dependent upon desired dry times and pot life properties. Other types of accelerators which can be effective are tertiary amines like Desmorapid PP (Bayer) at 0.2-0.5% on resin solids or zinc carboxylates (8% zinc octoate) at up to 0.2% on resin solids. Carboxylic acids, such as acetic or formic acid, tend to reduce the effectiveness of tin catalysts and therefore inhibit the reaction, resulting in a longer pot life. As the acid evaporates, the reaction in the film proceeds as normal. 2,4-Pentanedione will chelate with the tin compound and also increase pot life without adversely effecting the film cure. PIGMENTATION Most pigments used with conventional urethane systems are suitable for use with these high solids coatings. Typical pigments include phthalocyanine blues and greens, titanium dioxide, toluidine red, etc. Fillers and extenders include calcium carbonate, silicas, barium sulfate, wollastonite, and talcs, with the most beneficial (least durability degradation) being barium sulfate and wollastonite. Some pigments such as zinc oxides, zinc phosphates, some organic pigments and certain types of carbon blacks may act as a catalyst and reduce pot life. Pigment volume concentration (PVC) is also important in formulating high solid coatings, just as it is in conventional coatings. Usually a high PVC (around 40-45%) provides faster dry. Gloss can be maximized by reducing the pigment/binder ratio and using flow and leveling additives. SOLVENT SELECTION As with conventional systems, the solvent blend should consist mainly of oxygenated solvents, such as ketones or esters. Aromatic solvents, such as toluene and xylene, are not active solvents for acrylic polyurethane systems, but have good latent solvency when used in blends with other solvents. ® AROLON 6473 PAGE 4 OF 5 Special anhydrous grades of solvents such as MAK (methyl n-amyl ketone) and PM Acetate are usually required. The water content of the solvent blend used in the polyisocyanate should not exceed 0.05% (500 ppm). Alcohols and glycol ethers are not recommended because of their ability to react with the isocyanate. ADDITIVES Most additives used with conventional coatings are suitable for high solid coatings. Since low VOC coatings tend to be heavier (more viscous) and “fluffier” than conventional systems, defoamers are even more important for release of air during both pigment dispersion and application of the coating. Suitable defoamers would include BYK-077 (BYK Additives and Instruments) as well as 1-2% mineral spirits. Suitable flow-control agents include surfactants such as Anti-Terra-U (BYK Additives and Instruments) and Nuosperse 657 (Elementis), silicone and acrylic resins such as Modaflow (Allnex), and amino resins (urea formaldehyde). Bentonite clays, colloidal silicas, and castor based thixotropes such as Bentone SD-2 and M-P-A 60 X (Elementis) are employed for sag resistance and pigment suspension. Since isocyanates react with water (OH groups), the incorporation of a moisture scavenger is recommended, especially for high build systems. The isocyanate can react with water from the pigment or solvent, and also with water condensed onto the paint droplets as it is atomized and sprayed. Solvent evaporation causes cooling resulting in moisture condensation. Moisture scavengers include molecular sieves and triethyl ortho formate. ® AROLON 6473 PAGE 5 OF 5