Paint and Coatings AdditivesArchitectural Coatings

New Low-VOC Coalescents for Exterior Coatings

Dibenzoate Technology - A Viable Alternative

By William Arendt, Rebecca Hanes, Emily McBride

Low-VOC figure 1 — Credit: Emerald Performance Materials

Low-VOC figure 2 — Credit: Emerald Performance Materials

Low-VOC figure 3 — Credit: Emerald Performance Materials

Low-VOC table 1 — Credit: Emerald Performance Materials

Low-VOC figure 4 — Credit: Emerald Performance Materials

Low-VOC table 2 — Credit: Emerald Performance Materials

Low-VOC figure 5 — Credit: Emerald Performance Materials

Low-VOC figure 6 — Credit: Emerald Performance Materials

Low-VOC figure 7 — Credit: Emerald Performance Materials

References

Butt, J.; Joshi, M.;Strepka, A. Film-Forming Aid to Minimize Volatile Organic Content in Exterior Applications, Proceedings of the 37th Waterborne, High-Solids and Powder Coatings Symposium, New Orleans, LA, 2010, 31-45.
Arendt, W.; McBride, E. New Dibenzoate Plasticizer/Coalescent Blends for Low-VOC Coating Formulations, Proceedings of the 38th Waterborne, High-Solids and Powder Coatings Symposium, 2011, 419-429.
Arendt, W.; McBride, E. New Dibenzoate Plasticizer/Coalescent Blend for Low-VOC Coating Formulations, Coatings Tech2011, 8, 26-33.
Arendt, W.; Hanes, R.; McBride, E. New Plasticizer and Coalescent for Graphics Applications, Proceedings of the 39th Waterborne, High-Solids and Powder Coatings Symposium, 2012, 442-457.
Arendt, W.; Hanes, R.; McBride, E. Advances in Low-VOC Coalescent, PCI, 2012, 28, No. 8, 40-44.
Arendt, W.; McBride, E.; Hanes, R. Low VOC Tri-dibenzoate Blend in Exterior Coatings and Interior Paint Based on Harder Acrylic Polymers, Presentation at the Cleveland Coatings Society Sink or Swim Conference, June 4-5, 2012.
Arendt, W.; McBride, E.; Hanes, R. Low VOC Tri-dibenzoate Blend in Exterior Coatings and Interior Paint Based on Harder Acrylic Polymers, Presentation at the Coatings Trends and Technologies Conference, September 11-12, 2012.
RHOPLEX™ VSR-50, Product Data Sheet for Rohm and Haas, Feb 2008.
RHOPLEX™ MULTILOBE (ML 200), Product Data Sheet for Dow.

APPENDIX 1 » Exterior paint formulation used in the evaluation.

Acrylic flat

Ingredient Type	Chemical Name/Class	Pounds
Water	Dihydrogen oxide	254
Thickener	Hydroxyethylcellulose, glyoxal treated	3
Propylene glycol	1,2-propanediol	16
Surfactant	Nonionic surfactant, HLB = 12.6/dispersant	1
Defoamer	Oil-based defoamer	2
Dispersant	Sodium salt of maleic anhydride copolymer	14
Pigment	Titanium dioxide (rutile)	200
Extender	Sodium-potassium alumina silicate	140
Extender	Diatomaceous earth alumino-silicate	20
In-can preservative	5-chloro-2-methyl-4-isothiazolin-3-one/ microbicide	2
Biocide	4,5-dichloro-2-N-octyl-3(2H)-isothiazolone/fungicide,algicide	6
em>Grind
Let down:
Polymer⁸	Acrylic emulsion, Tg 9 ºC/emulsion	360
Polymer	Opaque polymer, particle size: 0.4 microns	66
Coalescent	Plasticizer	8/td>
Surfactant	Nonionic surfactant/HLB = 12.6	0.5
Defoamer	Oil-based defoamer	2/td>
Thickener	Nonionic HEUR/thickener	3
Total		1108

Acrylic semigloss

Ingredient Type	Chemical Name/Class	Pounds
Water	Dihydrogen oxide	65
Dispersant	Hydrophobic copolymer/pigment dispersant	13
Surfactant	Sulfosuccinate/anionic surfactant	2
Defoamer	Polysiloxanes, 0 VOC/silicone defoamer	0.5
Pigment	Titanium dioxide (rutile)	225
Filler	Hydrous aluminum silicate, particle size=0.2 microns/extender	10
In-can preservative	5-chloro-2-methyl-4-isothiazolin-3-one/ microbicide	2
Grind
Letdown
Polymer 7	Acrylic emulsion, Tg 12 ºC	484
Polymer	Opaque polymer, particle size: 0.4 microns	43
Plasticizer/coalescent	Plasticizer	4
Surfactant	Nonionic surfactant, HLB = 12.6/wetting aid	1
Defoamer	Polysiloxane	1
Propylene glycol	1,2-propanediol	7
Ammonia (28%)	28% ammonium hydroxide aqueous	2
Thickener	Nonionic HEUR	17
Thickener	Nonionic HEUR	4
Biocide	20% IPBC (3-iodo-2-propynyl-n-butylcarbamate)/fungicide	8
Water	Dihydrogen oxide	154
Total		1040

APPENDIX 2 »Test methods employed.

Test	Reference/Method
pH	ASTM E70
Stormer viscosity	ASTM D562
ICI viscosity	ASTM D4287
Contrast ratio, reflectance, and CIE values	ASTM D2805, E97, D2244 – 3 mil wet film over a Leneta 3B chart dried for 5 days. Contrast ratio is reflectance of black over reflectance over white.
Gloss and sheen	ASTM D2243
Low-temperature coalescence	Paint and equipment conditioned at 40 °F for 2 h. Paint drawn down on a Leneta Form 3B to 6 mils wet. The films were dried horizontal for 24 h and rated (10= Excellent, 0= Very poor).
Flow and leveling	ASTM D4062
Dry adhesion	ASTM D3359B
Wet adhesion	ASTM D6900
Early blister	ASTM D714
Accelerated dirt pick up	A paint sample was applied by 3 mil drawdown on an aluminum Q36 panel. The panel was allowed to dry overnight before placing in the QUV chamber for 7 days of exposure. The top half of the panel was covered and synthetic dirt (brown iron oxide dispersion) spread evenly over the uncovered portion. The panel was placed in a 120° oven for 30 min, removed from the oven and the loose dirt was removed by tapping on the panel. The top portion of the panel was uncovered. The % Y reflectance of the tested part and the untested part were read. The % Y reflectance retained was reported. The higher the %, the better the dirt pick up resistance.
Blocking resistance	ASTM D4946
Scrubbability	ASTM D2486
Exterior panel preparation	Yellow Southern pine was used; application was at a natural spread rate of 400 square feet per gallon. South 45° and 90° panels self primed, two coats. North 90° the wood was primed with a waterborne acrylic primer and two coats of experimental paints. Two ounces of phthalo blue colorant were added to each paint. The 4 mils wet colored paint was applied to aluminum panels.