Post on 26-Jun-2020
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
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
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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30
35
Epikote 828/ref. Dimer acid modified epoxy
Man
dre
l Fle
x [
mm
]
0
50
100
150
200
250
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
0
5
10
15
20
25
30
35
Ref (0%) 2,5% 5,0% 7,5%
Percentage B-Tough C2
Man
drel
flex
ibili
ty [m
m]
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40
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Köni
g ha
rdne
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
0
5
10
15
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30
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Ref (0%) 2,5% 5,0% 7,5%
Percentage B-Tough C2 (active a.k.a. rubber part)
Man
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
Man
drel
Fle
x [m
m]
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150
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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
0
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15
20
25
30
35
E1001/ref.E828/ref.
828 with B-Tough C2 (5%)
Epoxy functionalised toughening agent
Man
drel
Fle
x [m
m]
0
50
100
150
200
Har
dnes
s [s
]
Mandrel Flex König hardness
brittle
flexible
Epikote with hardener Ancamide 23861 week @RT
0
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
Man
drel
flex
ibili
ty
[mm
]
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250
Köni
g ha
rdne
ss [s
]
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.