capa polycaprolactone polyols - triiso · 2013. 2. 19. · formulations in formulation b capa ® is...
TRANSCRIPT
Capa® -Polycaprolactone polyols
Reactive diluents for 2K PU
Capa® - Polycaprolactones
� Aliphatic, liquid, low viscosity polyols suitable as reactive diluents
in 2K PU formulations
By adding Capa® - polycaprolactones to an 2K solvent borne formulation
following benefits can be obtained:
� Decreased VOC with maintained viscosity
� High gloss and excellent aspect due to perfect compatibility between Capa and the acrylic
� Improved drying time and increased flexibility
� Improved scratch and abrasion resistance
� Improved outdoor durability
Products and formulations
All formulations are identical apart from the polyol part
� A - Reference system - with polyester, f = 4− Commercial high solids formulation based on acrylic polyol with 10 % of
polyester polyol
� B - Acrylic with Capa 3050, MW=540g/mol, f = 3
− The polyester in the reference formulation is replaced on OH basis. The amount of Capa 3050 has been adjusted to match the OH content of the polyester.
� C - Acrylic with 2*Capa 3050, MW=540g/mol, f = 3− Twice the amount needed to match the OH content of the polyester polyol has been
added to the formulation
� Tolonate HDT LV 2 at a ratio of NCO/OH=1.05 for all the systems
� All formulations have been cured at room temperature
Formulations
� In formulation B Capa® is added to match the OH content of the polyester reference. Formulation C contains twice that amount while keeping an equal OH molar ratio.
* Solvent ratio 8:67:25 ** BYK-315, BYK-322. BYK-358
A B C
Part AReference
system
Acrylic/ Capa
3050
Higher amount
of Capa 3050
Acrylic polyol (75 % in BuAc) 4.5 % OH 71.43 71.43 61.5
Polyester ref (78 % in BuAc) 5.4 % OH 7.7
Capa 3050 9.4 % OH 3.4 7.0
Solvent mixture
(BuAc+Solvesso 100+MAK)*18.0 22.2 28.6
Additive package** 0.9 0.9 0.9
DBTL (1 % in BuAc) 2.0 2.0 2.0
Total 100.0 100.0 100.0
Part B NCO/OH 1.05
Tolonate HDT LV2 30.8 30.8 30.8
Solvent mixture
(BuAc+Solvesso 100+MAK)*
to adjust viscosity to 22 sec
in DIN cup 4 at 23 C
16.6 10.4 0
Effect on VOC
VOC in g/l to obtain 22 sec in DIN cup 4 at 23 C
355
360
365
370
375
380
385
390
395
A - Reference system B - Acrylic/Capa 3050 C - Acrylic/2*Capa 3050
-25 g/L
� By addition of Capa® to the formulation it is possible to further decrease the VOC content without compromising the viscosity
Pot life
0
20
40
60
80
100
120
140
160
180
A - Reference system B - Acrylic/Capa 3050 C - Acrylic/2*Capa 3050
Pot life in min
� Capa® - polycaprolactones are very reactive
� The pot life can be adjusted by the amount of catalyst used in the formulation
Drying times
Measure performed Erichsen coatmaster 509 MC
� Addition of Capa®-polycaprolactones decreases the drying time of the coatings
0
100
200
300
400
500
600
700
800
900
1000
A - Reference system B - Acrylic/Capa 3050 C - Acrylic/2*Capa 3050
Dust free time in min
Tack free time in min
Measure performed Erichsen coatmaster 509 MC
0
10
20
30
40
50
60
70
80
90
100
A - Reference system B - Acrylic/Capa 3050 C - Acrylic/2*Capa 3050
Gloss at 20° Gloss at 60° Haze
Coatings appearance
� Capa® - polycaprolactones are fully compatible with acrylic resins and do not affect the aspect or appearance of the coatings
Scratch resistance
� Addition of Capa® - polycaprolactones increases the scratch resistance of the coating
Scotch Brite gloss retention
Gloss measured at 60 degree angle
0
20
40
60
80
100
0 25 50
Number of double rubs (385 g)
Gloss retention, % A - Reference system
B - Acrylic/Capa 3050
C - Acrylic/2*Capa 3050
Percentage of the initial gloss remaining after the coatings have been scratched using a Scotch Brite sponge
Scratch resistance was performed on Taber Model 550 (rotation speed 0.5 tr/min) Applied on Taber glass panels (hole in the center) at RT
� The resistance of the coatings towards permanent scratches is largely increased with the addition of Capa® - polycaprolactones
Scratch resistance
Weight (force) needed to obtain permanent scratch
0
50
100
150
200
250
A - Reference system B - Acrylic/Capa 3050 C - Acrylic/2*Capa 3050
Weight in g
Abrasion resistance
Taber abrasion on steel
CS10 wheels, 500 g load, 1000 cycles
0
5
10
15
20
25
30
35
A - Reference system B - Acrylic/Capa 3050 C - Acrylic/2*Capa 3050
mg of coating removed during
the abrasion
weight loss, mg
� The coating formulations containing Capa® - polycaprolactones show a superior abrasion resistance compared to the reference formulation containing a conventional polyester
Chemical resistance
Layer thicknesses of 150µm wet which corresponds to 40 µm dry on Q-panel
Chemical spot test
0
1
2
3
4
5
A - Reference system B - Acrylic/Capa 3050 C - Acrylic/2*Capa 30505 = no m
ark, 0 = destroyed surface
Ethanol (48%) 5min Skydrol (5 min)
Xylene (5 min) Acetic acid 10% (1h)
Sulfuric acid 10%(1h) Ammoniacal solution 10% (1h)
5 = no mark and 0 = destruction of the film
� All coatings show very good chemical resistance
� Slight improvement of Xylene resistance was observed for form. B
Flexibility
� Addition of Capa largely increases the flexibility of the system
� Proportional to the amount of Capa
AFNOR impact resistance Evaluated on coatings heated during 24h at 80°C and then cooled to -25°C for 3h
� The high flexibility of Capa® - polycaprolactones offers improved
flexibility even at – 25 °C
0
10
20
30
40
50
60
70
80
90
100
A - Reference system B - Acrylic/Capa 3050 C - Acrylic/2*Capa 3050
Indirect impact in
cm.kg
Direct impact in
cm.kg
Pendulum hardness
Pendulum Koenig hardness (in s) of coatings cured at RT
0
20
40
60
80
100
120
140
160
A - Reference system B - Acrylic/Capa 3050 C - Acrylic/2*Capa 3050
D+1
D+3
D+7
Measured on glass, layer thicknesses of 150µm wet which corresponds to 45µm dry
Capa® - polycaprolactones offer increased flexibility without any significant impact on the final hardness of the coatings
QUV-B exposure Decrease in gloss at 20°
Accelerated weathering (QUV-B)
0
10
20
30
40
50
60
70
80
90
100
0 500 1000 1500 2000
h in QUV-B
Relative gloss decrease, %
A - Reference system
B - Acrylic/Capa 3050
C - Acrylic/2*Capa 3050
� Coatings containing Capa® - polycaprolactones are more resistant to UV-B
exposure in terms of gloss retention
� Measured on Al panels : 45µm dry of clearcoat over white basecoat, -
� Cycle : succession of 4 hours periods of UV-B exposure at 60°C each followed by 4 hours periods of condensation at 40 ° C
ConclusionsBy replacing a standard polyester reactive diluent in a 2K solvent borne formulation with Capa® - polycaprolactones the following benefits are obtained:
� Lower VOC content at comparative viscosity
� A decreased drying time of the coating
� Highly improved scratch and abrasion resistance
� Improved outdoor durability and humidity resistance
� Increased flexibility, even at low temperatures
� No compromise on final hardness
� Excellent coating properties with less amount of polyol :
– comparing the amount of Capa® needed in the formulation vs the standard polyester