1. Continuing Development of Low VOC Benzoate Coalescents: Direct-to-Metal Coatings
William D. Arendt
Marianne Conner, Emily McBride, and Gina Macy
Emerald Kalama Chemical, LLC Kalama, Washington
Western Coatings Symposium
October 27, | Las Vegas, NV
© Copyright 2015, Emerald Kalama Chemical, LLC. All rights reserved.

2. Agenda Introduction VOC Data Evaluation Recap/Summary
Background on plasticizers for coatings
Summary of performance of benzoates
Formulating coatings with benzoates
VOC Data
Evaluation
Direct-to-metal coatings
Primer and gloss layer
Initial and revised formulations
Recap/Summary

3. Introduction

4. Plasticizers in Coatings
Plasticizers have been used in coatings for decades
Solution coatings
Waterborne architectural paint
Industrial coatings
Types of plasticizers used
Phthalates (BBP, DOP, DBP, DIBP)
Dibenzoates (DPG and DEG dibenzoates, blends, PG dibenzoate)
Others (including monobenzoates)
Why?
In past, to improve film formation or tooling properties
VOC of true plasticizers is significantly less than traditional higher VOC coalescents

5. Waterborne Direct-to-Metal Coatings
Waterborne coatings for direct-to-metal applications
Used in indoor and outdoor applications, professional and DIY markets for home and commercial structural use
Attributes – Used on ferrous surfaces to be used with or without primer, can be used on other surfaces
Example applications: doors, windows, trim, shutters, fences, garage doors, outdoor furniture, railing and wrought iron
Coalescents typically used
TMPDMIB – 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate
Glycol ethers – DPM, DPnB and others (water soluble types)
Plasticizers, in blends or by themselves:
Di and monobenzoates
Phthalates

6. Recent Benzoate Coalescent Development
New dibenzoate platform created and introduced at Waterborne Symposium
Blend of three dibenzoates; initial product of platform: 975P
Also introduced in 2011: a diblend of historic dibenzoates tailored to use in latex systems: 850S
Diethylene glycol/dipropylene glycol dibenzoate blend
In 2013, one new dibenzoate blend commercialized: 500P
Blend of diethylene and dipropylene glycol dibenzoate designed for lower VOC
lowest VOC of the line of dibenzoates

7. Summary of Performance of Recent Di- and Monobenzoates in Paint
Dibenzoate evaluation data in interior and exterior architectural paints compared to 2,2,4-trimethyl-1,3- pentanediol monoisobutyrate indicated:
Significantly reduced VOC
Better gloss in higher sheen paints indicating better film formation and an add to the binder system
Better scrub resistance in most instances
Similar blocking resistance
Similar performance on exposure fences
All parameters observed
Dirt pickup similar out to 36 months (most recent period of testing)

8. Formulating with Benzoate Coalescents
Partitioning in Binary Blends of Coalescents
Hard Acrylic emulsion mixed with 975P
Hard Acrylic emulsion mixed with TEGDO

9. Formulate to Benzoates
Determine VOC contributed by the low VOC coalescent
VOC will be reduced with low VOC coalescent
Adjustments for performance can be made
Replace existing coalescent
TMPDMIB – one for one replacement
In some hard styrenated acrylic types partitioning may require a change in mix intensity, order of addition, type of surfactant etc.
Other types – Add to level of performance required, start at a one for one replacement
If the efficiency is less than expected, consider:
Intensity of mixing – in binary blend – test MFFT or LTC – if this works use in adjusted paint manufacture. If it does not:
Try a ternary blend (emulsion, existing nonionic surfactant and coalescent at level of use in paint formulation)

10. Formulate to Benzoates (Continued)
If above does not work – look at effect of HLB of the nonionic surfactant on MFFT or LTC.
If this works, use alternate nonionic (generally lower than existing HLB) and evaluate in paint in existing formula
If the change in surfactant does not provide an optimal response, change order of addition as used in ternary blend – level of surfactant may need adjustment but most likely not
After the formulation has been adjusted, test the formulation completely to ensure proper performance

11. Goals Discuss reduction of VOC possible with use of benzoate esters
Present the use of the dibenzoates in direct-to-metal applications

12. Reducing VOCs

13. Coalescents Evaluated
DIBENZOATES
975P: DPG/DEG/PG dibenzoate triblend
850S: Second generation dibenzoate binary blend
500P: Third generation dibenzoate diblend
CONTROLS
DPM: Dipropylene glycol monomethylether
DPnB: Dipropylene glycol n-butylether
TMPDMIB: 2,2,4-Trimethyl-1,3-pentanediol monoisobutyrate
BBP: Butyl benzyl phthalate

14. Coalescent Physical Properties
Boiling Point
Vapor Pressure
Flash Point
°C at 5 mm Hg
[760 mm Hg])
(mm Hg at 25°C)
(°C)
DPM
[180]
4.0 x 10-1
120
DPnB
[230]
6.8 x 10-2
TMPDMIB
110 [254]
1.3 x 10-2
975P
215 [>350]
3.6 x 10-6
193
850S
180 [>330]
9.0 x 10-5
202
500P
236 [>350]
1.0 x 10-8
232

16. VOC, ASTM D6886

17. US VOC: Proposed Modification of ASTM D6886
GC VOC Method - Methyl Palmitate BP Marker
Boiling Point at atmospheric pressure of methyl palmitate: ºC.
In California, South Coast Air Quality Management District (SCAQMD) is considering adoption of this method to quantify VOC. TMPDMIB, TMPDDIB and many other coalescents will be 100% VOC by this definition (Draft Method 313) if set to this marker.

18. DTM Coating Performance

19. Introduction Several formulations were included in the study Coatings
Gloss coating or primer
Based on prescreen data (MFFT of binary blend)
Formulations evaluated as received
System modified to reflect a necessary change for proper partitioning
Polymers used
Polymer 1 – 100 (100% acrylic, Tg = 35ºC, MFFT = 33°)
Polymer 2 – 35 (styrenated-acrylic, MFFT = 56°C)
Coatings
Gloss DTM (Polymer 1 – 100 , Polymer 2 – 35)
Primer DTM (Polymer 2 – 35)

20. Physicals and Coatings Test
Paint Physicals
% PVC
% Volume Solids
% Volume Solids w/ Dibenzoates
100% acrylic, Tg = 35ºC
Gloss 18 38 40
Styrenated acrylic, Tg = 56ºC
Primer 41
16.5 37
Viscosity (KU and ICI)
Contrast Ratio
Reflectance
Gloss
Color
Wet Edge/Open Time
Heat Stability
Freeze/Thaw Stability
All tests conducted – not all will be discussed
Low Temperature Coalescence
Flow and Leveling
Scrub Resistance
Flexibility
Hardness Development
Adhesion
Flash Rust
Salt Fog Exposure

21. Gloss DTM White Paint Based on Polymer 1

22. Gloss DTM White VOC, Regulated and Material
VOC < 100 g/L
VOC < 50 g/L
Based on ASTM D2369 raw material volatilities of individual coatings components.

23. Partitioning in Polymer Dispersion 1 – Binary Blend
All coalescents had partitioned where resultant MFFT was less than 40ºF (4.4ºF).

24. Acrylic DTM White – Polymer 1
Function
Control
Series 1
Series 2
Local water
49.8
Dispersant
7.8
Non-ionic surfactant grind aid, HLB = 8
2.0
pH adjust
Non-ionic surfactant (HLB = 12.6) -
1.50
Defoamer
0.3
Titanium dioxide
209.2
5.0
Binder (Tg = 35ºC)
515.1
129.5
4.0
3.0
2.5
Coalescing aid
16.0 16
Low VOC Coalescents
20.0
8.0
Solvent (DPM)
14.0
Corrosion inhibitor
9.0
23.7
HEUR thickener 1
HEUR thickener 2
2.3

25. Polymer 1 – Top Coat Performance: Series 1 (High Dibenzoate Loading)

26. GLOSS: Acrylic, DTM White

27. BLOCK RESISTANCE: Acrylic, DTM White
Avanse MV 100

28. SCRUB RESISTANCE: Acrylic, DTM White Based on Polymer 1
Avanse MV 100

29. Polymer 1 – Top Coat Performance: Series 2 Equal Loading

30. Gloss

31. Block Resistance

32. Salt Fog Test (396 Hours) @ 396 Hours TMPDMIB 975P 850S 500P
Rust Rating
9-P
7-P
8-P
Blisters 6M
6MD
Scribe Creep 7

33. White DTM Primer: Based on Polymer 2

34. VOC Regulated and Material
Original Formulation
 Coalescent
VOC (g/L)
Include Water
Exclude Water
TMPDMIB 71
108
975P 49 75
850S
500P
Revised Formulation
 Coalescent
VOC (g/L)
Include Water
Exclude Water
TMPDMIB 71
108
975P 38 58
850S
500P 57

35. Polymer 2 Partitioning - Diblend

36. Formulations, White DTM Primer
Function
2:1 Original
(DPnB: BBP)
Original –
No Solvent
Revised
Local water 81
Dispersant 18
Non-ionic surfactant 3
pH adjust 1
Defoamer
1.5
Titanium dioxide
100
Calcium carbonate
200
Anti-corrosion pigment 15
Corrosion inhibitor 25
Binder ( Tg = 30ºC)
425
0.5
130.9 10
Thickener 4
Solvent (DPnB)
38.3
28.7
Coalescent
19.1
57.4
2.4
Total
1074.7

37. Original – Block Resistance

38. Original – Hardness Development

39. Revised

40. Revised - Set to Touch Time

41. Revised - Block Resistance

42. Revised - Hardness Development

43. Salt Fog Test @ 495 Hours TMPDMIB 975P 850S 500P Rust Rating 8-P 9-P
Blisters
4MD 4M
6MD
Scribe Creep 6 8 7

44. DTM Topcoat – Polymer 2

45. VOC Regulated and Material
Original Formulation
 Coalescent
VOC (g/L)
Include Water
Exclude Water
TMPDMIB 85
137
975P 3 4
850S
500P 2
Revised Formulation
 Coalescent
VOC (g/L)
Include Water
Exclude Water
TMPDMIB 89
144
975P 46 75
850S 74
500P

46. Formulations, DTM Topcoat
Function
Original
Revised
Local water
64.71
Dispersant
6.38
Non-ionic surfactant
1.96 -
Non-ionic surfactant (HLB = 8.7)
Defoamer
0.98
Thickener
0.49
Titanium dioxide pigment
185.87
Corrosion inhibitor
19.62
Binder (MFFT = 56ºC)
563.19
71.76
pH adjust
Solvent (DPnB)
34.97
Coalescent
69.93
Flash rust inhibitor
4.90
Total
992.24
991.26

47. Original - Gloss

48. Original – Hardness Development

49. Revised

50. Revised - Gloss

51. Revised – Block Resistance

52. Revised – Hardness Development

53. Salt Fog Test @ 594 Hours TMPDMIB 975P 850S 500P Rust Rating 8-P 7-P
Blisters 6F 4F
Scribe Creep 6 7

54. Recap and Conclusions
The VOC test methodologies and standards can vary significantly, but physical parameters indicate which coalescent is lowest VOC
Besides being low VOC, dibenzoates function very well in paint with advantages
Formulation with benzoates is normally a one-for-one replacement for TMPDMIB, but if there are differences, formulation changes are simple
Data on the performance of dibenzoates in direct-to-metal coatings indicate that dibenzoates can replace TMPDMIB or TMPDDIB.
As with other coatings applications , dibenzoates may require a slightly different formulation approach (not always a drop-in)
Possibly can also replace glycol ethers
The old “saws” about plasticizer use in coatings are simply not true with the right low VOC coalescents

55. Disclaimer
The information contained herein is believed to be reliable, however is based upon laboratory work with small scale equipment and does not necessarily indicate end-product performance. Because of variations in methods, conditions and equipment used commercially in processing these materials, Emerald makes no representations, warranties or guarantees, express or implied, as to the suitability of the products for particular applications, including those disclosed, or the results to be obtained. Full-scale testing and end-product performance are the responsibility of the user. Emerald Performance Materials shall not be liable for and the customer assumes all risk and liability for use and handling of any materials beyond Emerald’s direct control. Nothing contained herein is to be considered as permission, recommendation nor as inducement to practice any patented invention without permission of the patent owner.

56. Acknowledgements
Permission to publish by Emerald Kalama Chemical LLC, Ed Gotch, CEO
Marianne Conner, Debbie Davidson, Gina Macy, Emily McBride, Sarah Strother, and Ian Query for data development
Emerald Kalama’s Research and Applications Lab Building
Some of the Emerald Kalama Research Staff
in front of the lab

57. Appendix

58. Test Methods 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 – 3 mil wet film on Leneta 3B chart
dried for five days.
Low Temperature Coalescence
Paint and equipment conditioned at 40°F for 2 hours. Paint drawn down on a Leneta Form HK to 6 mils wet. The films were dried horizontal for 24 hours and rated (see lab rating system below).
Thermogravametic Analysis (TGA)
TA Q-500 TGA employed. Isothermal under air with a flow rate of 160 ml/minute. 5 mg sample size
VOC, Oven method
EPA 24, D-2369, 3 ml toluene used with 0.3 g sample.
Lab Rating System
10= Excellent, 0= Very poor
VOC, GC method 1
ASTM D-6886, post add of 1.5% coalescent to a commercial zero VOC paint
VOC, GC method 2
ISO
Boiling point, atmospheric or reduced pressure
Reported values as available reported for reduced pressure or atmospheric pressure. Most of atmospheric extrapolated for reduced pressure data
Flow and Leveling
ASTM D4062 – Leneta test blade used to apply paint. Dried paint rated.
Dry Adhesion
ASTM D3359B – Paint was applied to dried aged alkyd with a brush and dried for 7 days before testing by cross hatch tape adhesion.

59. Test Methods Continued
Reference/Method
Scrubbability
ASTM D2486 – Paint applied at 7 mils wet to a leneta P121-10N chart and dried at room temperature for 7 days. A 10 shim was employed with abrasive media (SC-2). Failure was a continuous thin line at the shim.
Wet adhesion
ASTM D A gloss alkyd (ICI / Devoe Devguard Medium Green) was applied by drawdown and cured for 6 to 12 weeks at room temperature on a Leneta P121-10N scrub chart. A drawdown of the test paint was made perpendicular to the gloss alkyd and allowed to dry for 24 hours. The coating was then crosshatched into squares with sufficient pressure to cut the latex paint film but not enough pressure to cut the alkyd film. The test panel was soaked for 5 minutes in water. The panel was placed in the scrub machine so that the squares were in the path of the nylon brush. The % removed after 500 cycles were reported.
Sag resistance
ASTM D-4400
Dirt pick up
3 mil of paint applied to aluminum panel and dried for 24 hours. Then it was placed in the QUV chamber for 7 days of exposure. The top half of the panel was covered up and the synthetic dirt was spread evenly over the un-covered portion. The panel was placed in a 120’ oven for 30 minutes. The panels were 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.
Porosity Ratio
ASTM D3793 – A 6 mil applicator was used to apply paint film to white Leneta WB charts. The ambient (dried 7-Days) and low temperature conditioned at 40ºF (dried 48 hours) were stained with 10 mils of Leneta Staining Medium for 5 minutes. The stain was washed off with mineral spirits and then air dried 3 hours. The difference in porosity of the unstained and stained was calculated for each the ambient and 40ºF conditioned panels. The ratio of the porosities of the 40ºF to the ambient was calculated.

60. Test Methods Continued
Flow and Leveling
ASTM D4062 – Leneta test blade used to apply paint. Dried paint rated.
Dry Adhesion
ASTM D3359B – Paint was applied to dried aged alkyd with a brush and dried for 7 days before testing by cross hatch tape adhesion.
Wet Edge/Open Time
Paint applied with notched drawdown bar on Leneta WB chart. At 1 minute intervals ¼ of 1” brush was dipped into the paint and brushed 10 strokes across the line. The wet edge was rated with the lab system.
Scrubbability
ASTM D2486 – Paint applied at 7 mils wet to a leneta P121-10N chart and dried at room temperature for 7 days. A 10 shim was employed with abrasive media (SC-2). Failure was a continuous thin line at the shim.
Blocking Resistance
ASTM D4946 – 3 mil wet films applied to Leneta WB chart and the films were dried for 7 days. Blocking was tested face to face at ambient and 120°F with a 1 Kg weight in place. The samples were separated and rated.
Color Acceptance
Tinted paint (with 2 ounces/gallon black) drawn down at 3 mils. After one minute the paint is rubbed up in the unsealed area. The color acceptance is then rated.
Touch Up
Touch up was tested with the paint prepared for the color acceptance. Self primed Upsom was used and applied with a Linzer 2”Bristle and polyester brush at RT and 40°F and allowed to dry overnight. The test paint was applied and rated for sheen uniformity and color difference.
Low Temperature Touch-Up
(Brush over Roll)
ASTM D7489 – Wet tinted paint was roller applied onto 1 sq.ft. Upson Board panels, all conditioned in constant temperature environmental room and dried for 24 hours. For touch up, the paint, brush, and panel conditioned at 40ºF for 4 hours, and immediately 5 strokes vertical and 5 strokes horizontal of the conditioned paint were applied as second coat onto panel. Panel replaced into 40ºF and condition for additional 24 hours. ASTM Standardized Scoring System used to rate for visual and instrumental: Rating of 1 = Poor, 3 = Good, 5 = Excellent.
Mudcracking
Paint was applied with a Leneta Antisag meter (14-60 mils) on an HK chart at ambient and 40°F. After 24 hour dry the greatest mils without cracking noted.

61. Test Methods Continued
Reference/method
Freeze/Thaw
ASTM D2243 – Frozen at 0°C and thawed at ambient. 3 cycles used.
Heat Stability
ASTM D1849 – Tested at 120°F for two weeks.Initial and final viscosities taken.
Drying Time
ASTM D1640 – 3 mil wet film applied to Leneta 3B, set to touch determined at ambient.
VOC method 3
ISO in 85% PVC paint or neat coalescent