Continuing Development of Low VOC Benzoate Coalescents:

Direct-to-Metal CoatingsWilliam D. Arendt

Marianne Conner, Emily McBride, and Gina Macy

Emerald Kalama Chemical, LLC Kalama, WashingtonWestern Coatings Symposium

October 27, 2015 | Las Vegas, NV

© Copyright 2015, Emerald Kalama Chemical, LLC. All rights reserved.

2

®Agenda

• Introduction– 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

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 2011 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)

Formulating with Benzoate Coalescents

Hard Acrylic emulsion mixed with 975P Hard Acrylic emulsion mixed with TEGDO

Partitioning in Binary Blends of Coalescents

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

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

CoalescentBoiling 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 120DPnB [230] 6.8 x 10-2  TMPDMIB 110 [254] 1.3 x 10-2  975P 215 [>350] 3.6 x 10-6 193850S 180 [>330] 9.0 x 10-5 202500P 236 [>350] 1.0 x 10-8 232

       

16

®VOC, ASTM D6886

VOC 0

10

20

30

40

50

60

Control 0 VOC

1.5% Wt TMPDMIB

1.5% Wt 975P

1.5% Wt 850S

VO

C, g

/L

VOC0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

We

igh

t %

Lo

st

17

®

0.0

0.5

1.0

1.5

% W

t

TMPDMIB

975P

850S

500P 0

10

20

30

40

50

VO

C (g

/L)

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.

Boiling Point at atmospheric pressure of methyl palmitate: 319 - 321ºC.

US VOC: Proposed Modification of ASTM D6886

GC VOC Method - Methyl Palmitate BP Marker

DTM Coating Performance

19

®Introduction

• Several formulations were included in the study– 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

®

Viscosity (KU and ICI)Contrast Ratio Reflectance Gloss Color Wet Edge/Open TimeHeat Stability Freeze/Thaw Stability

Low Temperature Coalescence Flow and Leveling Scrub Resistance Flexibility Hardness Development Adhesion Flash Rust Salt Fog Exposure

Paint Physicals % PVC % Volume Solids % Volume Solids w/ Dibenzoates

100% acrylic, Tg = 35ºC Gloss 18 38 40

Styrenated acrylic, Tg = 56ºCPrimer 40 38 41

Gloss 16.5 37 41

All tests conducted – not all will be discussed

Physicals and Coatings Test

Gloss DTM White Paint Based on Polymer 1

22

®

Based on ASTM D2369 raw material volatilities of individual coatings components.

VOC < 100 g/L

VOC < 50 g/L

Gloss DTM WhiteVOC, Regulated and Material

23

®Partitioning in Polymer Dispersion 1 – Binary Blend

1-Day3-Day

7-Day

0

4

8

12

16

Binder975P

TMPDMIB850S

500P

MFF

T (º

C)

All coalescents had partitioned where resultant MFFT was less than 40ºF (4.4ºF).

24

®Acrylic DTM White – Polymer 1Function Control Series 1 Series 2

Local water 49.8 49.8 49.8

Dispersant 7.8 7.8 7.8

Non-ionic surfactant grind aid, HLB = 8 2.0 2.0 2.0

pH adjust 2.0 2.0 2.0

Non-ionic surfactant (HLB = 12.6) - - 1.50

Defoamer 0.3 0.3 0.3

Titanium dioxide 209.2 209.2 209.2

Local water 5.0 5.0 5.0

Binder (Tg = 35ºC) 515.1 515.1 515.1

Local water 129.5 129.5 129.5

pH adjust 4.0 4.0 4.0

Defoamer 3.0 3.0 3.0

Defoamer 2.5 2.5 2.5

Coalescing aid 16.0 - 16

Low VOC Coalescents 20.0 16

Local water 8.0 4.0 -

Solvent (DPM) 14.0 14.0 14.0

Corrosion inhibitor 9.0 9.0 9.0

Local water 23.7 23.7 -

HEUR thickener 1 4.0 4.0 4.0

HEUR thickener 2 2.3 2.3 2.3

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

26

®

20º Gloss 60º Gloss0

10

20

30

40

50

60

70

80

90

100TMPDMIB

975P

850S

Glo

ss

GLOSS: Acrylic, DTM White

27

®BLOCK RESISTANCE: Acrylic, DTM White

1 Day, RT 1 Day, 120F 7 Days, RT 7 Days, 120F0

1

2

3

4

5

6

7

8

9

TMPDMIB

975P

850S

Cure-Time, Condition

Ra

tin

g,

AS

TM

D4

94

6

28

®

TMPDMIB 975P 850S0

100

200

300

400

500

600

700

800

Sc

rub

Cy

cle

s t

o F

ail

ure

SCRUB RESISTANCE: Acrylic, DTM White Based on Polymer 1

Polymer 1 – Top Coat Performance:Series 2 Equal Loading

30

®Gloss

20º Gloss 60º Gloss 85º Gloss50

60

70

80

90

100

TMPDMIB

975P

850S

500P

Glo

ss

31

®Block Resistance

1 Day RT 7 Day RT0

1

2

3

4

5

6

7

8

9

10

TMPDMIB

975P

850S

500P

Ra

tin

g,

10

= e

xc

ell

en

t

32

®

@ 396 Hours TMPDMIB 975P 850S 500P

Rust Rating 9-P 7-P 8-P 8-P

Blisters 6M 6MD 6MD 6M

Scribe Creep 7 7 7 7

Salt Fog Test (396 Hours)

White DTM Primer: Based on Polymer 2

34

®VOC Regulated and Material

Coalescent VOC (g/L)Include Water Exclude Water

TMPDMIB 71 108975P 49 75850S 49 75500P 49 75

Coalescent VOC (g/L)Include Water Exclude Water

TMPDMIB 71 108975P 38 58850S 38 58500P 38 57

Original Formulation

Revised Formulation

35

®Polymer 2 Partitioning - Diblend

36

®Formulations, White DTM Primer

Function 2:1 Original(DPnB: BBP)

Original – No Solvent Revised

Local water 81 81 81Dispersant 18 18 18Non-ionic surfactant 3 3 3pH adjust 1 1 1Defoamer 1.5 1.5 1.5Titanium dioxide 100 100 100Calcium carbonate 200 200 200Anti-corrosion pigment 15 15 15Corrosion inhibitor 25 25 25Binder ( Tg = 30ºC) 425 425 425Defoamer 0.5 0.5 0.5Local water 130.9 130.9 130.9Corrosion inhibitor 10 10 10Thickener 4 4 4Solvent (DPnB) 38.3 0 28.7Coalescent 19.1 57.4 28.7Thickener 2.4 2.4 2.4

Total 1074.7 1074.7 1074.7

37

®Original – Block Resistance

1 Day RT 7 Day RT0

2

4

6

8

10

12

2:1 DPnB/BBP

TMPDMIB

975PRa

tin

g

38

®Original – Hardness Development

0 5 10 15 20 25 300

5

10

15

20

25

30

35

40

45

50

2:1 DPnB/BBP

Texanol

975P

Days

Ko

nig

Ha

rdn

es

s

Revised

40

®Revised - Set to Touch Time

Series10

5

10

15

20

25

BBPTMPDMIB975P850S500P

Set t

o To

uch

Tim

e (m

in)

41

®Revised - Block Resistance

1 Day RT 7 Day RT0

1

2

3

4

5

6

7

8

9

10

BBP

TMPDMIB

975P

850S

500P

Ra

tin

g,

10

= e

xc

ell

en

t

42

®Revised - Hardness Development

0 5 10 15 20 25 300

5

10

15

20

25

30

35

40

45

BBPTexanol975P850S500P

Days

Koni

g Ha

rdne

ss

43

®

@ 495 Hours TMPDMIB 975P 850S 500P

Rust Rating 8-P 8-P 9-P 9-P

Blisters 4MD 4M 6MD 6MD

Scribe Creep 6 8 7 7

Salt Fog Test

DTM Topcoat – Polymer 2

45

®VOC Regulated and Material

CoalescentVOC (g/L)

Include Water Exclude Water

TMPDMIB 85 137975P 3 4850S 3 4500P 2 3

CoalescentVOC (g/L)

Include Water Exclude WaterTMPDMIB 89 144975P 46 75850S 46 74500P 46 74

Original Formulation

Revised Formulation

46

®Formulations, DTM TopcoatFunction Original Revised

Local water 64.71 64.71

Dispersant 6.38 6.38

Non-ionic surfactant 1.96 -

Non-ionic surfactant (HLB = 8.7) - 1.96

Defoamer 0.98 -

Thickener 0.98 0.49

Titanium dioxide pigment 185.87 185.87

Corrosion inhibitor 19.62 19.62

Binder (MFFT = 56ºC) 563.19 563.19

Local water 71.76 71.76

pH adjust 1.96 1.96

Solvent (DPnB) - 34.97

Coalescent 69.93 34.97

Flash rust inhibitor 4.90 4.90

Thickener - 0.49

Total 992.24 991.26

47

®Original - Gloss

20º Gloss 60º Gloss 85º Gloss0

10

20

30

40

50

60

70

80

90

100

TMPDMIB

975P

850S

500P

Glo

ss

48

®Original – Hardness Development

0 5 10 15 20 25 300

5

10

15

20

25

30

35

TMPDMIB

975P

850S

500P

Days

Ko

nig

Ha

rdn

es

s

Revised

50

®Revised - Gloss

20º Gloss 60º Gloss0

10

20

30

40

50

60

70

80

TMPDMIB

975P

850S

500P

Glo

ss

51

®Revised – Block Resistance

1D RT 7D RT0

1

2

3

4

5

6

7

8

9

10

TMPDMIB

975P

850S

500P

Ra

tin

g,

10

= e

xc

ell

en

t

52

®

0 5 10 15 20 25 300

10

20

30

40

50

60

TMPDMIB975P850S500P

Days

Ko

nig

Ha

rdn

es

sRevised – Hardness Development

53

®Salt Fog Test

@ 594 Hours TMPDMIB 975P 850S 500P

Rust Rating 8-P 7-P 9-P 9-P

Blisters 6F 6F 4F 6F

Scribe Creep 6 7 7 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

Some of the Emerald Kalama Research Staffin front of the lab

Emerald Kalama’s Research and Applications Lab Building

• 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

Appendix

58

®Test MethodsTest Reference/MethodpH 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 chartdried 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 11890-2

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 ContinuedTest Reference/MethodScrubbability 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 D6900 - A gloss alkyd (ICI / Devoe Devguard 4308-6650 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 ContinuedTest Method

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 ContinuedTest Reference/methodFreeze/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 16000 in 85% PVC paint or neat coalescent