capa polycaprolactone polyols - triiso€¦ · in formulation b capa ® is added to match the oh...

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


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


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


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


Weight in g

Abrasion resistance

Taber abrasion on steel

CS10 wheels, 500 g load, 1000 cycles

0

5

10

15

20

25

30

35


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


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


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

capa polycaprolactone polyols - triiso€¦ · in formulation b capa ® is added to match the oh...

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