Toughen–up your coating with B-ToughTM

Epoxy functional dimer technology for epoxy coatings

European Coatings Conference February 28-29, 2012

Berlin

Content

Introduction to toughening

Introduction to dimer acids in epoxy systems

Prove of concept

Results of B-Tough C2TM versus conventional technologies

Conclusions

Introduction to toughening

Introduction to dimer acids in epoxy systems

Prove of concept

Results of B-Tough C2 versus conventional technologies

Conclusions

What is toughness?

A mattress is flexible but too soft

Glass is hard but too brittle

What is toughness?

= impact resistance

Cracks are caused by: impact/collision exposure to severe conditions

• temperature • UV radiation/sun light • chemicals (salt water)

And what if a material is not tough?

Hard and non-flexible materials are vulnerable to cracking

Why are cracks bad?

Cracks undermine the protective effect of coatings

Why are cracks bad?

Cracks undermine structural integrity

Epoxy toughened systems

Adhesives: Construction

Aerospace Automotive

Electronics

Hard disk Conductors Motherboard

Assembly Windmill

Epoxy toughening is a well-known concept in several epoxy applications

Conventional technologies used for toughening

Type Viscosity [mPa.s]

Remarks

Non reactive block copolymer 3.600

Present as individual (separate) particles in epoxy matrix

Silicon modified toughener (reactive)

35.000 Silicon core, epoxy functional shell, chemically bonded to epoxy matrix, high viscosity

Elastomer toughener (reactive) 200.000 Epoxy functionalised CTBN rubber, very high viscous

Market trends

VOC reduction Low VOC, high solid trend Unions & Occupational Safety & Health authorities

Reduce time & costs Faster cure Wider over coating interval Low temperature cure Easy to apply

Higher performance Longer lifetime New functionalities: e.g. self cleaning

Croda offerings to the market

Pripol TM Dimer acid

Priamine TM

Dimer diamine

B-Tough TM

Toughening agent

Flexibility hardness high VOC

Low viscous Flexibility Low VOC

Flexibility and Hardness

Polyamide curative Epoxy modification

Dimer Diamine curative

Epoxy modification

year 2011 2011 1980

Content

Introduction to toughening

Introduction to dimer acids in epoxy systems

Prove of concept

Results of B-Tough C2 versus conventional technologies

Conclusions

Why? Dimer acid use in epoxy resins Dimer acid use in epoxy resins

Brings flexibility (vibration/stress absorption) Enhances hydrophobicity, weatherability and compatibility with organic

matrices (tar, hydrocarbon resins)

Large hydrocarbon part (C36) Hydrophobic Hydrolytic resistance of derivatives Affinity for non-polar matrices and surfaces

Irregular non-crystalline structure Flexibility Low Tg

Flow, wetting

HOOC COOH HOOC COOH

Dimer acid use in epoxy resins

Dimer acid technology traditionally used in epoxy resins In polyamide curatives In modified epoxies; flexibility at cost of hardness though

0

5

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Epikote 828/ref. Dimer acid modified epoxy

Man

dre

l Fle

x [

mm

]

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Har

dness

[s]

Mandrel Flex König hardness

C H 3

C H 3

O C H 3

C H 3

O

O

O

O H O H

O

C H 3

O

C H 3

O O

O

O

brittle

flexible

Dimer technology for impact modification

Low glass transition temperature and low polarity of dimer acid makes it suitable for flexibilisation

Dimer acid too small as soft segment (Mw 580) for phase separation

B-Tough™ epoxy functional dimer technology allows incorporation of larger molecular weight soft segments

Potentially resulting in phase separated morphology

Resulting in better toughening performance etc.

Modification of rigid polymers with apolar soft segments

A special way of impact modification

Crystalline or high-Tg amorphous ‘hard’ segments

Large low-Tg amorphous ‘soft’ segments flock together, driven by polarity difference, forming large domains that provide impact strength. Copolymer, chemically linked, therefore no stability issues.

Phase separated morphology

Soft segments form rubbery particles in hard epoxy matrix

Results in impact strength

Rubbery particles restrict crack growth Energy of crack is absorbed by the rubber By plastic deformation, shear banding,

cavitation

Toughness: reducing crack growth while maintaining a hard matrix

For hardness and good high temperature performance Toughness requires 2-phase structure

Additional advantages

Due to the incorporation of B-Tough in the epoxy the moisture diffusion will be reduced as the dimer technology is extremely hydrophobic

B-Tough can be added as additive to the system No volatile toxic or smelly monomers Not susceptible to thermal or oxidative degradation Very low glass transition temperatures

Easy to formulate: low viscous

Epoxy functionalised toughening agent B-Tough C2 Typical values

• Viscosity much lower than many conventional tougheners easier to formulate with B-Tough

• Compatible enough to react, phase separate during cure

Product code EEW Typical [g/eq]

Rubber content [%]

Viscosity @ 25°C Typical [mPa.s]

B-Tough C2 1875 40 3100

Explanation ‘rubber content’

B-Tough C2 contains 40% rubber phase:

So 5% ‘rubber’ requires 5 = 12.5 % w/w B-Tough C2 0.40

Example: if 100 g contains 5% rubber, it contains 12,5 g B-Tough C2

‘Rubber’-part: 40%

Epoxy-part: 20%

Benzyl alcohol-part: 40%

B-Tough C2

Content

Introduction to toughening

Introduction to dimer acids in epoxy systems

Prove of concept

Results of B-Tough C2 versus conventional technologies

Conclusions

Toughening in coating systems Liquid vs. solid epoxy resin, various hardeners

EPIKOTE™ 828 Epoxy toughening agent: 5% rubber phase Hardener:

Ancamide™ 3201: polyaminoamide adduct (previously known as SIQ 2201) Ancamide 2386 : modified amidoamine

Formulated to 80% solids with xylene/butanol (4/1)

EPIKOTE 1001 Epoxy toughening agent: 5% rubber phase Hardener:

Ancamide 3201: polyaminoamide adduct (previously known as SIQ 2201) Ancamide 2386 : modified amidoamine

Formulated to 70% solids with xylene/butanol (4/1)

Solid epoxy 1001 requires more solvent than liquid epoxy 828

Method/formulation

Preparation

Formulation (in parts by weight): Epoxy resin

Epikote 828 100 B-Tough C2 23 Solvent 44

Xylene/Butanol (4:1)

Curing agent Ancamide 3201 62.8

Properties Solid content 80% Viscosity @25°C 150 mPa.s

Initial

Rubber phase 5%

Toughening in coating systems

Evaluation Test conditions of the coating 1 wk @ 25°C

100µ wet

Mechanical properties: Flexibility (Mandrel) Hardness König Impact at 25 /4 / -25°C

Direct Indirect

Chemical resistance Chemicals Salt spray

Impact of varying amount of B-Tough C2 on hardness and flexibility

Impact of B-Tough C2 on hardness and flexibilityEpikote 828, cured with SIQ 2201 (Ancamide 3201), curing 1 week at 25°C

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Ref (0%) 2,5% 5,0% 7,5%

Percentage B-Tough C2

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drel

flex

ibili

ty [m

m]

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200

Köni

g ha

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ss [s

]

FlexibilityHardness

Higher load of B-Tough C2 improves flexibility; hardness drops only little bit

Impact of B-Tough C2 on hardness and flexibilityEpikote 828, cured with SIQ 2201 (Ancamide 3201), curing 1 week at 25°C

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Ref (0%) 2,5% 5,0% 7,5%

Percentage B-Tough C2 (active a.k.a. rubber part)

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drel

flex

ibili

ty [m

m]

02040

6080100120140

160180200

Kön

ig h

ardn

ess

[s]

Flexibility Hardness

brittle

flexible

Impact of varying amount of B-Tough C2 on impact resistance

Impact resistance for varying percentages of B-Tough C2Epikote 828, cured with SIQ 2201 (Ancamide 3201), curing 1 week at 25°C

0255075

100125150175200

Ref (0%) 2,5% 5,0% 7,5%

Percentage B-Tough C2

Impa

ct re

sist

ance

[kg.

cm]

Direct impact (25°C)

Indirect impact (25°C)

Direct impact (-25°C)

Indirect impact (-25°C)

Higher load of B-Tough C2 improves impact resistance for both high and low temperatures Freedom of formulation due to ease of mixing

Mandrel flexibility/hardness 5% rubber phase, B-Tough C2, Ancamide 3201

Allows change from solid to liquid resin for VOC reduction Hardness of 828 system, non-brittle, with flexibility of 1001 system

Epikote with hardener Ancamide 32011 week @RT

0

510

1520

2530

35

E1001/ref.E828/ref.

828 with B-Tough C2 (5%)

Epoxy functionalised toughening agent

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drel

Fle

x [m

m]

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250

Har

dnes

s [s

]

Mandrel Flex (100 µm) König hardness

brittle

flexible

Impact resistance 5% rubber phase, B-Tough C2, Ancamide 3201

Epikote with hardener Ancamide 32011 week @RT

0255075

100125150175200

E1001/ref.

E828/ref.

828 with B-Tough C2 (5%)

Epoxy functionalised toughening agent

Impa

ct re

sist

ance

[kg.

cm]

Direct impact (25°C)

Indirect impact (25°C)

Indirect impact (4°C)

Mandrel flexibility/hardness 5% rubber phase, B-Tough C2, Ancamide 2386

Coatings with this hardener are already flexible

But toughening agent does improve impact strength (next slide)

Epikote with hardener Ancamide 23861 week @RT

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25

30

35

E1001/ref.E828/ref.

828 with B-Tough C2 (5%)

Epoxy functionalised toughening agent

Man

drel

Fle

x [m

m]

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100

150

200

Har

dnes

s [s

]

Mandrel Flex König hardness

brittle

flexible

Epikote with hardener Ancamide 23861 week @RT

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25

50

75

100

125

150

175

200

E1001/ref.

E828/ref.

828 with B-Tough C2 (5%)

Epoxy functionalised toughening agent

Impa

ct re

sist

ance

[kg.

cm]

Direct impact (25°C)Indirect impact (25°C)Indirect impact (4°C)Indirect impact (-25°C)

Impact resistance 5% rubber phase, B-Tough C2, Ancamide 2386

So…

…the B-Tough C2 technology proved to work. How about performance versus conventional technologies?

Content

Introduction to toughening

Introduction to dimer acids in epoxy systems

Prove of concept

Results of B-Tough C2 versus conventional technologies

Conclusions

Viscosity of toughened mixtures

*) All formulations: • Epikote 828 as resin • Xylene/butanol (4/1), 10%, as solvent • Ancamide 3201 (SIQ 2201) as curing agent

Formulation:

Toughening agent

[%rubber on formulation]

Viscosity of pure toughening agent

[mPa.s]

Dynamic viscosity of mixture;

after 10 min @ 25°C [mPa.s]

Viscosity increase vs reference;

after 10 min @ 25°C [%]

Reference 0 490

B-Tough C2 5 3.100 537 10

Non-reactive block copolymer

5 3.600 537 10

Silicon modified 5 35.000 900 84

Elastomer modified 5 200.000 620 27

Mandrel flexibility/hardness 5% rubber phase, against alternative toughening technologies

Epikote 828 with hardener Ancamide 32011 week @RT

05

101520253035

828/ref.

B-Tough C2

non reactive block copolymer

silicon modifie

d

elastomer modifie

d

Epoxy toughening agent

Man

dre

l Fle

x [m

m]

0

50

100

150

200

250

Har

dn

ess

[s]

Mandrel Flex König hardness

brittle

flexible

Impact resistance 5% rubber phase, against alternative toughening technologies

Epikote 828 with hardener Ancamide 32011 week @RT

0255075

100125150175200

828/ref.

B-Tough C2

non reactive block copolymer

silicon modified

elastomer modifie

d

Epoxy toughening agent

Impa

ct re

sist

ance

[kg.

cm]

direct impact @ 25°Cindirect impact @ 25°Cindirect impact @ -25°C

Impact of curing temperature on hardness and flexibility

Impact of B-Tough C2 on hardness and flexibilityafter curing at different temperatures for 1 week

Epikote 828, cured with SIQ 2201 (Ancamide 3201)

05

101520253035

Ref (0%), 5

°C

5%, 5

°C

Ref (0%), 2

5°C

5%, 2

5°C

Ref (0%), 3

5°C

5%, 3

5°C

Percentage B-Tough C2 and curing temperature

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Köni

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]

Flexibility König hardness

At low temperature, curing remains slow At high(er) temperatures, trend is similar to that at room temperature: B-Tough C2 increases flexibility, at the same time remains hardness

brittle

flexible

Impact of curing temperature on impact resistance

Impact resistance after curing at different temperatures for 1 weekEpikote 828, cured with SIQ 2201 (Ancamide 3201)

0255075

100125150175200

Ref (0%

), 5°C

5%, 5

°C

Ref (0%

), 25°C

5%, 2

5°C

Ref (0%

), 35°C

5%, 3

5°C

Percentage B-Tough C2 and curing temperature

Impa

ct re

sist

ance

[kg.

cm]

Direct impact (25°C)

Indirect impact (25°C)

Direct impact (-25°C)

Indirect impact (-25°C)

Too sticky to measure due to low temp

Similar trend at higher temperature as seen at room temperature: B-Tough C2 improves impact resistance significantly at only 5% addition.

Taber test results

Coating layer [mm]

Weight loss [mg]

Reference 75.5 115.8

5% B-Tough C2 84.1 122.7

Non-reactive block copolymer 81.6 174.9

Silicon modified toughening agent 77.3 115.2

Elastomer modified toughening agent 80.0 149.7

ISO 7784-2: 1000 cycles, C17 wheel (medium abrasive)

Content

Introduction to toughening

Introduction to dimer acids in epoxy systems

Prove of concept

Results of B-Tough C2 versus conventional technologies

Conclusions

Conclusions

Toughen-up the epoxy coating with epoxy functionalised toughening agent B-Tough C2 1. B-Tough C2 allows to achieve the flexibility of Epikote 1001 (solid epoxy) based

solvent coatings in Epikote 828 (liquid epoxy) based coatings, with the hardness of an Epikote 828 coating.

2. B-Tough C2 allows improvement of flexibility and whilst maintaining the surface hardness.

3. B-Tough C2 also works well at low temperatures.

Additional features of B-Tough C2: Low viscous, ease of handling. Thermal and oxidative stability guaranteed.

More information needed?

For more detailed information, please take a look at www.croda.com and

register.

Thank you for your attention.