From Quality to Innovation

Novel Light Stabilizers for

Waterborne and Epoxy Coatings

Dr. I-Chyang Lin

Everlight USA Everlight Chemical Industrial Corporation

September, 2013

Everlight Chemical Profile

• Founded in 1972 in Taiwan • Listed in Taiwan Stock Exchange

since 1988 • Consolidated Revenue (2012): USD$ 205 Millions • 1,500 Employees world-wide

2011 2012

Everlight

Sun Light

…

UV-C UV-B UV-A IR

100 200 300 400 500 600 700 800 900 1000 l [nm]

ultraviolet (UV) rays(100nm-400nm) 7% radiation energy

visible light (400nm-760nm) 71%

ultra red rays(760nm-50um) 22%

Ultraviolet Light Spectrum

UV-A 400nm-320nm : 88% Polymer Degradation

Skin Suntan

UV-B 320nm-290nm

9% Polymer

Degradation Skin Sunburn

UV-C <290nm

3% The ozone

layer blocking

Why Light Stabilizers for Coatings

Degradation

Protective Coating

Substrate (metal,wood,plastic)

Examples of coating degradation.. ?

UV-light

• gloss loss

• cracking

• chalking

• color change

• delamination

• Corrosion ?

Without Light Stabilizers

Manhattan, NY

Newark, New Jersey

George Washington Bridge, New York

Barcelona

Denmark (offshore windmill farm)

Stockholm

near Dusseldorf

Dusseldorf

Why Light Stabilizers for Coatings

Degradation

Protective Coating

Substrate (metal,wood,plastic)

Examples of coating degradation.. ?

UV-light

• gloss loss

• cracking

• chalking

• color change

• delamination

• Corrosion ? !

Without Light Stabilizers

Color Retention and Corrosion Reduction Clear Waterborne 2K Epoxy Coating

Clear w/b epoxy coating over white base-coated steel substrate Exposure：700 hours, ASTM G154-1 Q-U-V (UVA-340)

Light Stabilizer : EP5 (incorporated in Hardener)

Blank

3% EP5

Liquid Coating Raw Materials

• BINDER - (Polymer/Resin) Forms a film above the substrate and holds the pigment in place. – E.g. acrylic, alkyd, epoxy/polyamide, polyurethane, polyester,

phenolic, polyvinyl butyral, chlorinated rubber, silicone, etc. • SOLVENT - (includes water) to adjust solids content and modify viscosity and

drying time • PIGMENT

– Color pigment (organic/inorganic) for color, hiding power and durability.

– Extender pigment (filler) for property and cost. E.g. TiO2, KAOLIN - (China Clay, aluminum silicate), fumed silica, talc (magnesium silicate ), calcium carbonate, barium sulfate, Mica (sheet silicate), etc.

• ADDITIVES for various purposes, – e.g. flow promoters, x-linking agents, rheology modifiers,

dispersants, wetting agents, catalysts, biocides, light stabilizers, matting agents, antioxidants, flame retardants.

Prevention of Polymer Degradation

X X*

UV Absorber

hv R. RH

O2

O2 1

O2

ROO.

RO.

ROOH RH RH

HALS (Hindered Amine Light Stabilizer)

Commercial UV absorbing products

Organic UV Absorbers

Oxanilide

Benzophenone

Benzotriazole

Triazine

Others

Inorganic UV Cutter

TiO2

ZnO

Carbon Black

Other Pigments

Organic UV Absorbor types

N

H

ON

O

H

2-Hydroxy Phenyl Benzotriazole (BZTs)

EV74,76, EV-80,81 2-Hydroxy Benzophenone

NN

N

O

R3

R1

R2

HO O

O R

H

N

N

N

O

O

R

R

R

R

R

H

2-Hydroxy Phenyl s-triazines (2HPT) Oxanilide

Mechanism of UVA O O

HO O

H

hv

-kT

Exciting state △E=hÅ Ground state

Proton transfer

Exciting state

Ground state

Proton transfer

NN

N

OH

R

NN

+N

OH

R

hv

-kT

Benzophenone Benzotriazole

UVA and Beer’s Law

* *

l

especially bottom and below

Recommendations for Industrial Coatings

Pigmented coat

Substrate

Clearcoats UVA : 2% (1 - 3%) HALS: 1% (1 - 2 %)

Ratio UVA:HALS 2:1 *Performance Blends: 1.5-3%

Pigmented: UVA : 1% (0 - 2 % depending on pigmentation) HALS : 2% (1 - 3 %)

Ratio UVA:HALS 1:2 (Opaque - HALS only?)

(based on resin solids)

Clear coat

Substrate

Cross-Section of industiral coatings

Waterborne Coatings

Conventional Light stabilizers in Waterborne Coating Formulations

• Designed for solvent based systems

• Need special procedure and extra efforts to incorporate in waterborne systems: – Dilute in co-solvents – Disperse with extra care

Liquid Hydroxyphenyl-benzotrialzole (UVA)

1. Dispersion test in Acrylic Waterborne Resin

(5g UVA/100g -Acrylic Waterborne Resin)

(5g UVA/100g -PU Waterborne Resin)

Dispersing of traditional liquid benzotrialzole in waterborne system is difficult.

Traditional UV Absorbers: Difficult Dispersion in Waterborne Systems

2. Dispersion test in PU Waterborne Resin

filter filter

(5g Ev.-AQ1/100g -Acrylic Waterborne Resin)

(5g Ev.-AQ1 /100g -PU Waterborne Resin)

1. Dispersion test in Acrylic Waterborne Resin

2. Dispersion test in PU Waterborne Resin

Liquid AQ stabilizers are easily dispersible in waterborne systems!

Eversorb® AQ Light Stabilizers:

Great for Waterborne Coatings

filter filter

Liquid performance products (based on AQ technology)

AQ Technology Light stabilizers for Waterborne Coating Formulations

• Very high active content – 90% actives – 100% total solids

• Easy incorporation – Stir-in products – Post addable – No need for cosolvent

• Effective performance – color and gloss retention

Light Stabilizers for Waterborne Coatings – AQ Technology

Chemicals class Recommended System

Functions

AQ1

Blend UV-Absorber

+ HALS

-Nonionic -Amphoteric

-Anionic

Prevent discoloration of clear coatings and

enhanced gloss retention

AQ2

Blend UV-Absorber

+ HALS

-Cationic Prevent discoloration of clear coatings and

enhanced gloss retention

AQ3 UV-Absorber

-Nonionic -Amphoteric

-Anionic

Prevent discoloration of clear coatings

AQ4 HALS

-Nonionic -Anionic

Prevent discoloration of pigmented coatings

and enhanced gloss retention

AQ Stabilizers: 0.5 - 3 % (based on resin solids content)

Light Stabilizers for Waterborne Coatings – AQ Technology

Chemicals class Recommended

System Functions

AQ5 NOR HALS

-Nonionic -Anionic

• Prevent discoloration of pigmented coatings • Enhanced gloss retention • Suitable for alkyd and acidic systems

AQ6 UV-Absorber

-Nonionic -Anionic

• Prevent discoloration of clear coatings • High performance and efficiency • Recommended for UV cut / filtering

AQ7 UV-Absorber

-Nonionic -Amphoteric

-Anionic

• Imprrove weathering stability of waterborne UV curable coatings • High performance and efficiency • Provide efficient UV cut / filtering

AQ Stabilizers : 0.5 - 3 % (based on resin solids content)

Resin ： Polyurethane (PU) Waterborne Clear Coat ing Exposure Time : 1000 hours Additives :EVERSORB® AQ1& AQ3 Test Methods ：ASTM G154-2 (Q-U-V with UVB-313 light bulb )

ΔE=13.1 G=53

ΔE=1.2 G=75

ΔE=13.1 G=53

ΔE=2 G=83

Improvement of Color & Gloss Retention for PU Water-borne Clear Wood Coatings

Eversorb® AQ1 vs. AQ3:

for color retention, AQ3 is better than AQ1,

for gloss retention, AQ1 is better than AQ3.

After Test

Before Test (covered)

Fig.2-1 Delta difference color (” E) Fig.2-2 60o Gloss

0 2 4 6 8 10 12 14 16color change (ΔE)

Control

3% AQ1

20 30 40 50 60 70 80 90 10060 o Gloss

Control

3% AQ1

Fig.1-1 Color change (” E) Fig.1-2 60o Gloss

3% AQ3 3% AQ3

13.1

2

1.2

90

53

83

75

original original

Resin system： Waterborne Acrylic Pigmented :Island green NO. 420-6 Exposure Time : 2000 hours Additives:EVERSORB® AQ4 Test Methods ：ASTM G154-2 (Q-U-V with UVB-313 light bulb )

After Test

Before Test (covered)

ΔE=4 G=15

ΔE=0.29 G=45

Fig.2-1 Delta difference color (” E) Fig.3-2 60o Gloss

0 1 2 3 4 5 6color change (ΔE)

Control

1% AQ4

3% AQ4

10 15 20 25 30 35 40 45 50 55 6060 o Gloss

Control

1% AQ4

3% AQ4

55

15

35

45

4

0.88

0.29

original original 0 hrs

1000 hrs

1000 hrs

1000 hrs

0 hrs

1000 hrs

1000 hrs

1000 hrs

Improvement of Color Retention for Acrylic Waterborne Pigmented Coatings

Light stabilization of Epoxy/amine

Discoloration may occur over a relatively short period of time when epoxies are exposed to Ultra Voilet (UV) light radiation from indoor lighting, or natural sunlight.

Need of Light Stabilizer for Epoxy

• EP4: a liquid light stabilizer • Use level: 0.5 to 2.0 wt% based on total resin

solids (A+B). • Effective in amine-based epoxy systems, e.g.

epoxy flooring, wall coatings, and wind mill applications.

EP4 for Epoxy/amine System

2-K Epoxy System: PART-A: Conventional Epoxy

PART-B: Modified Cyclo-aliphatic amine

A:B=2:1(wt%) Curing: 24hrs @ 50℃ Samples: 3mm thick epoxy disks

Exposure: QUV 340nm (70℃*1.35W/m2) Test Time: 96hrs Additive: 0.5 wt% base on epoxy (A+B) Measurement: Delta yellowness index (” YI)

Blank Control

EP4

EP4 in Epoxy/amine (Conventional System)

Development of Light Stabilizers for Waterborne Epoxy Compatibility and Performance Studies

• Comparison of three different light stabilizer packages – Performance study – Dispersibility and compatibility in water

and in waterborne epoxy/hardener resins. – Design of Experiment (DOE) was used

” Y=44.9 ” Y=11.3

3% EP5

Blank

Improved Color Retention of Clear Waterborne 2K Epoxy Coating

After Test

Before Test (covered)

Clear epoxy coating over white base-coated substrate Exposure：152 hours, ASTM G154-1 Q-U-V (UVA-340)

Light Stabilizer : EVERSORB EP5 (incorporated in Hardener) Epoxy resin : POLYPOX E 403 Hardener : POLYPOX IH 7005W

Color Retention and Corrosion Reduction Clear Waterborne 2K Epoxy Coating

Clear w/b epoxy coating over white base-coated steel substrate Exposure：700 hours, ASTM G154-1 Q-U-V (UVA-340)

Light Stabilizer : EP5 (incorporated in Hardener)

Blank

3% EP5

Conclusions

• Eversorb® AQ light stabilizer technology (100%

solids) provides high active content, easy incorporation and weather stability for waterborne coatings.

• Eversorb® EP4 can improve UV resistence of solvent based epoxy coatings.

• Eversorb® EP5 can be easily incorporated, and is effective for the improvement of UV resistence of water based epoxy coatings. It helps maintain color retention, coating integrety, and corrosion performance.

• Genenal use level for coatings: 1-3% based on total resin solids.

Dr. Yaoshing Huang Yung-Chi Yang

Cedric Wackernagel

Special thanks

Thank you