additives influencing coatings properties · 11.11.2010, page 4, [email protected] –...
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Additives influencing Coatings
PropertiesMark Heekeren, Technical Service Automotive Coatings
16. November 2010
11.11.2010, Page 2, [email protected] – Surface Additives for Automotive Coatings
Common Defects in Coatings
• Poor flow and leveling
• Insufficient substrate wetting
• Foam stabilization / Popping
• Overspray acceptance
• Recoat ability (On-line Repair)
• Craters
Related to surface tension
11.11.2010, Page 3, [email protected] – Surface Additives for Automotive Coatings
Substrate Wetting: Impact of Surface Tension
Good substrate wetting:
paint < substrate
no additive0,1% BYK-333
11.11.2010, Page 4, [email protected] – Surface Additives for Automotive Coatings
Surface Tension
White spirit
80
70
60
50
40
30
20
Water
Melamine resins
Alkyd
resins
Acrylic
resins
Phosphatized steel
Non – treated steel
SMC-Polyester
mN
/mSolvents Resins Substrates
Aqueous
Xylene
11.11.2010, Page 5, [email protected] – Surface Additives for Automotive Coatings
Craters
Particle/
Droplet/
Dirt(28 mN)
Substrate 32 mN
Paint (30 mN)
11.11.2010, Page 6, [email protected] – Surface Additives for Automotive Coatings
Surface slip
higher content of dimethylgroups = higher surface slip
11.11.2010, Page 7, [email protected] – Surface Additives for Automotive Coatings
Leveling: Definition
Leveling
11.11.2010, Page 8, [email protected] – Surface Additives for Automotive Coatings
Leveling
What controls leveling?
• Rheology
• Time
• Surface tension
How to improve leveling?
• Deflocculating wetting & dispersing additives
(rheology in pigmented systems)
• Solvents (time)
• Resins
• Additives
11.11.2010, Page 9, [email protected] – Surface Additives for Automotive Coatings
Influence of rheology modifier on the Wave Scan Values
0,0
5,0
10,0
15,0
20,0
25,0
30,0
35,0
du dullness Wa 0,1-0,3mm Wb 0,3-1,0mm Wc 1-3mm Wd 3-10mm We 10-30mm
Without rheology agent
+ 0,5% Rheology modifier
+ 1.0% Rheology modifier
11.11.2010, Page 10, [email protected] – Surface Additives for Automotive Coatings
Silicones: Recommended Areas of Usage
For improvement of
Substrate wetting
Surface slip
Crater resistance
Adjustment of flow and leveling
........................different types of silicones are required
11.11.2010, Page 11, [email protected] – Surface Additives for Automotive Coatings
(CH3)3 Si O Si O Si O Si (CH3)3
CH3 CH3
y x
Alkyl mN/m
CH3
CH2CH3
(CH2)9CH3
21
26
32
Silicones: Adjustment of Surface Tension Reduction
Org
an
ic
Mo
dific
atio
n
Alk
yl
• Polyether (EO / PO)
• Aralkyl
• Polyester
• reactive
- Acrylic
- COOH
- OH
11.11.2010, Page 12, [email protected] – Surface Additives for Automotive Coatings
Influence of organic modified siloxanes on the surfacetension
Dosage
mN/m
BYK-300
BYK-315
BYK-331
30
29
28
27
26
25
BYK-310
BYK-378
Flo
w/L
evelli
ng
Substr
ate
wettin
g/
Anti C
rate
ring / S
urf
ace s
lip
11.11.2010, Page 13, [email protected] – Surface Additives for Automotive Coatings
Acrylates: Orientation by Controlled Incompatibility
optimal too compatibletoo incompatible
11.11.2010, Page 14, [email protected] – Surface Additives for Automotive Coatings
n
R1
C CH2
C = O
O
R2
R1 = - H (Acrylate)
- CH3 (Methacrylate)
R2 = - Alkyl
- Polyester
- Polyether
- Salt
Chemistry of Acrylates
11.11.2010, Page 15, [email protected] – Surface Additives for Automotive Coatings
“Standard” Silicone Additives vs.Silicone Macromer modified Acrylates
„Standard“ Silicone
- Modified silicone additive
- Silicone content: 30-60%
- Branched or linear modification
Silicone Macromers
- Silicone modified acrylate
- Silicone content: 2-15%
- Single or multi modificationwith Silicone Macromers
Polysiloxane
Polyether
Acrylate
11.11.2010, Page 16, [email protected] – Surface Additives for Automotive Coatings
Silicon modified acrylatesNo Ghosting Effect when Recoated
Active Silicone
BYK-3550
27,6 mN/m
27,4 mN/m
27,4 mN/m
Measurement of the surface energy of the dried film by contact angle
Wiped with isopropanol
Wiped with isopropanol
27,7 mN/m
25,8 mN/m
25,8 mN/m
11.11.2010, Page 17, [email protected] – Surface Additives for Automotive Coatings
Excellent Adhesion of Wrap Guard Foils
Low influence onto surface energy of the paint results in a better adhesion of
wrap guard foil and adhesives
Source: Sabine Nollmann, kontexta
11.11.2010, Page 18, [email protected] – Surface Additives for Automotive Coatings
Influence of the additive dosage onto the leveling
less active silicone
0,0
5,0
10,0
15,0
20,0
25,0
30,0
35,0
40,0
45,0
du dullness Wa 0,1-
0,3mm
Wb 0,3-
1,0mm
Wc 1-3mm Wd 3-10mm We 10-
30mm
0.02%
0.05%
0.10%
0.25%
bell-application of a 1K-OEM-clear coat, horizontal dried,
dosage: % active substance on total formulation
11.11.2010, Page 19, [email protected] – Surface Additives for Automotive Coatings
Influence of the additive dosage onto the leveling
very active silicone
0,0
5,0
10,0
15,0
20,0
25,0
30,0
35,0
40,0
45,0
du dullness Wa 0,1-
0,3mm
Wb 0,3-
1,0mm
Wc 1-3mm Wd 3-10mm We 10-
30mm
0.02%
0.05%
0.10%
0.25%
bell-application of a 1K-OEM-clear coat, horizontal dried,
dosage: % active substance on total formulation
11.11.2010, Page 20, [email protected] – Surface Additives for Automotive Coatings
Influence of the additive dosage onto the leveling
silicone modified acrylate
0,0
5,0
10,0
15,0
20,0
25,0
30,0
35,0
40,0
45,0
du dullness Wa 0,1-
0,3mm
Wb 0,3-
1,0mm
Wc 1-3mm Wd 3-10mm We 10-
30mm
0.02%
0.05%
0.10%
0.25%
bell-application of a 1K-OEM-clear coat, horizontal dried,
dosage: % active substance on total formulation
11.11.2010, Page 21, [email protected] – Surface Additives for Automotive Coatings
Influence of additive combination onto the leveling
bell-application of a 1K-OEM-clear coat, horizontal dried,
dosage: % active substance on total formulation
Silicone & Acrylate in combination
0,0
5,0
10,0
15,0
20,0
25,0
30,0
35,0
du
dullness
Wa 0,1-
0,3mm
Wb 0,3-
1,0mm
Wc 1-3mm Wd 3-
10mm
We 10-
30mm
0.10% less active silicone
0.1% less active silicone + 0.25%
Acrylate
0.05% very active silicone
0.05% very active silicone + 0.25%
Acrylate
11.11.2010, Page 22, [email protected] – Surface Additives for Automotive Coatings
Measurement of the surface tension by ring method
1K-OEM-clear coat
26
26,5
27
27,5
28
28,5
29
29,5
30
30,5
31
31,5
0 0,05 0,1 0,15 0,2 0,25 0,3
% active substance on total formulation
mN
/m
less active silicone
very active silicone
silicone mod. acrylate
acrylate
11.11.2010, Page 23, [email protected] – Surface Additives for Automotive Coatings
Measurement of the surface slip
1K-OEM-clear coat
Measurement of the force which
is needed to push a 500 g
weight over the coating layer
0
0,5
1
1,5
2
2,5
3
0 0,1 0,2 0,3
% active substance on total formulation
Newton
less active silicone
very active silicone
silicone mod. acrylat
acrylate
11.11.2010, Page 24, [email protected] – Surface Additives for Automotive Coatings
Summary:
• Surface additives are useful do adjust leveling
• It is necessary to find the optimum between leveling and substrate
wetting/anti crater properties
• Various additives provide different effects
• Combinations of additives are necessary for the optimal
performance
11.11.2010, Page 25, [email protected] – Surface Additives for Automotive Coatings
ANTI-TERRA®, BYK®, BYK®-DYNWET®, BYK®-SILCLEAN®,
BYKANOL®, BYKETOL®, BYKOPLAST®, BYKUMEN®, DISPERBYK®,
DISPERPLAST®, LACTIMON®, NANOBYK®, SILBYK® and VISCOBYK®
are registered trademarks of BYK-Chemie.
AQUACER®, AQUAFLOUR®, AQUAMAT®, CERACOL®, CERAFAK®,
CERAFLOUR®, CERAMAT®, CERATIX® and MINERPOL® are
registered trademarks of BYK-Cera.
This information is given to the best of our knowledge. Because of the
multitude of formulations, production, and application conditions, all the
above mentioned statements have to be adjusted to the circumstances
of the processor. No liabilities, including those for patent rights, can be
derived from this fact for individual cases.