1. Dr. Chip Palmer Ethox Chemicals, LLC Waterborne Symposium 2012
E-Sperse® FT 600 – A New Additive for Both Improved Freeze/Thaw Stability and Open Time (patent pending)
Dr. Chip Palmer
Ethox Chemicals, LLC
Waterborne Symposium 2012

2. Low VOC Coating Formulation Difficulties
Low VOC formulation->reduce/eliminate glycols -> reduced f/t stability
Reduced/eliminated glycols -> worse coalescence -> so use lower Tg resins
-> reduced f/t stability
Reduced/eliminated glycols -> faster drying -> reduced open time/wet edge
May 8, 2012
American Coatings Show 2012

3. American Coatings Show 2012
Wet Edge and Open Time
The period in which irregularities in a freshly applied coating can be repaired without resulting in brush marks is referred to as the open time, while the period in which a coating can be applied over an existing paint film without leaving lap marks is regarded as the wet edge time (Eastman def).
Various methods are used to impart “wet edge and open time” (WE/OT) to latex paints. In the past, ethylene or propylene glycol were used, but since these contribute to VOCs, cannot be used in low VOC paints. Glycols also give freeze/thaw stability.
New materials have been developed by a number of companies that do not contribute significantly to VOCs. Generally the materials are either wet edge/open time or freeze/thaw additives, but not both. E-Sperse® 600 does both functions.
May 8, 2012
American Coatings Show 2012

4. American Coatings Show 2012
Open Time Testing
ASTM method D7488 – 11 in a acrylic latex paint
Internal testing carried out by additizing an inexpensive commercial paint
External lab testing by adding to prepared paint bases – results similar (see following charts)
Checked f/t stability concurrently with open time/wet edge testing
Used a commercial FT additive for control
May 8, 2012
American Coatings Show 2012

5. Ethox Open Time and F/T Data
E-Sperse 600 gives good
open time and f/t
The best OT additive appears to be ERS 1833 (developmental)
May 8, 2012
American Coatings Show 2012

6. Outside Lab OT/WE and F/T Testing
Used an experimental design with both -5 C and -15 C Tg acrylic latexes.
Used ASTM method D , but used both right and left side for wet edge test (plotted separately).
All wet edge and OT comparisons were made relative to the control paint.
Added an extra open time test. Made ‘X’ in paint drawdown just before the brush out to avoid wet edge effects.
Retested with a lower viscosity control paint to match the lower average viscosity of the paints with additives. Found that the viscosity had no effect on open time.
Some of the test additives were the same as Ethox internal tests. Results qualitatively matched Ethox testing.
May 8, 2012
American Coatings Show 2012

7. Outside Lab Open Time/Wet Edge Testing
Sample ID
OT/WE Ranking
(1 = best)
F/T Ranking
ERS 01832
Commercial FT/OT additive 6 3
ERS 01833
5/6
ERS 01834
E-Sperse® OT-1616 5
ERS 01835 4
ERS 01836 2
ERS 01837
E-Sperse® 600 1
E-Sperse® 600 was clearly the best product of these tested.
May 8, 2012
American Coatings Show 2012

8. Freeze/Thaw Improvement
Additive approach can only go so far in improving F/T performance; to get F/T performance, other properties must be sacrificed.
Free surfactant in coating can cause problems such as reduced adhesion, blistering, reduced repellency, water sensitivity, pinholing, viscosity reduction, etc.
The use of Ethox reactive surfactants in latex manufacture “builds in” F/T stability into the latex so little or no F/T additive is needed, and the above problems are avoided. The surfactant is locked onto the surface of the latex particles where it needs to be to function, so much less total surfactant may be used, resulting in a cost savings and improved coating properties. Open time is also greatly improved.
To learn more about these reactive surfactants and their benefits in coatings, come listen to my talk at 4:30 today.
May 8, 2012
American Coatings Show 2012

9. Thanks for your attention!
Please come by our booth (#630)
May 8, 2012
American Coatings Show 2012