BECKOSOL AQ 510

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January 2011
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.
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
Perstorp
* 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
Arolon 6473 SAE-J1960kJ Weatherometer 60° & 20° Gloss
100
Gloss
80
60
40
20
0
0
1500
3000
4500
6000
7500
6000
7500
6000
7500
Exposure Hours
60° Gloss
20° Gloss
QUV-A340
Arolon 6473 QUV-A340 60° & 20° Gloss
100
Gloss
80
60
40
20
0
0
1500
3000
4500
Exposure Hours
60° Gloss
20° Gloss
QUV-B313
Arolon 6473 QUV-B313 60° & 20° Gloss
100
Gloss
80
60
40
20
0
0
1500
3000
4500
Exposure Hours
60° Gloss
20° Gloss
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 (Cytec), 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
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