IR REFLECTIVE PIGMENTS AND COLORANTS

David White

Heucotech, Ltd.

99 Newbold Road Fairless Hills, PA 19030-4307

215-736-0712

Davewhite@heubachcolor.com

Western Coatings ShowOctober 25-28, 2015Las Vegas, NV

Agenda

• Introduction• Challenge & Principle• Current main Application: Coil Coating / Roofing• Wood Coating• IR-reflecting Pigments in Multilayer Systems• Smart formulating of a Car Refinish System• Enhanced life-time of a composite Thermal Insulation System• Benefits

IR REFLECTIVE PIGMENTS

Introduction / Principle

IR REFLECTIVE PIGMENTS

IR REFLECTIVE PIGMENTS

cities with IR-absorbing surfaces (streets, pavements, dark roofs etc.)

temperature in the city center is 2°- 5°C higher compared to suburb

IR REFLECTIVE PIGMENTS

Solar emission spectrum of the sun

~50% of total energy in NIR (near infrared radiation)

NIR-radiationNIR-radiationUVUV

0 m N.N. (sea level) wavelength [nm]

slide 7 / 38

(NIR)-Radiation

Absorption

Reflection

Emission(Radiation und convection)

Heat flux

Interaction of (pigmented) surfaces with (NIR)-Radiation

IR REFLECTIVE PIGMENTS

slide 8 / 38

1. Reflectivity is the fraction of the solarenergy that is reflected by the surface (roof,wall) back to the sky. White color has thehighest solar reflectance, while black has thelowest.2. Emissivity is the emission of the absorbedheat as IR radiation. High infrared emissivityhelps to keep surfaces cool. Metallic surfacesfor example have a low infrared emissivity.3. Roof insulation

All 3 effects combined offer a system that significantly reduces heat build-up in buildings

IR REFLECTIVE PIGMENTS

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IR REFLECTIVE PIGMENTS

The surface temperature coated with an IR reflecting pigment increases less during the day time. High solar reflectance reflects the radiation before it effects the energy balance of the roof (building)!

It is mainly seen from sunset tomorning, where a surface with a high emissivity cools down faster.High infrared emittance gives the roof (building) the ability to radiate some of the absorbed solar energy!

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IR REFLECTIVE PIGMENTS

TSR means Total Solar Reflectance

TSR is the total amount of solar energy that is immediately rejected by the surface material (e.g. coating). This term is a key figure to describe the heat build-up of surfaces.A high TSR indicates efficient reflection – a low TSR value indicates a strong tendency to absorb NIR light and hence a significant heat build-up!It is useful to interpret the TSR value in relation to the matrix used and/or a reference pigment (e.g. titanium dioxide)IR-

slide 11 / 38

heat build-up of different pigments until equilibrium stage(20% Pigmentation in Alkyd/Melamine) according to ASTM D4803

max. DT20 °C

Paint characteristic: heat build-up

25,0

30,0

35,0

40,0

45,0

50,0

55,0

60,0

65,0

0 10 20 30 40 50 60

Irradiation time [min]

Tem

pera

ture

[°C

]

Titaniumdioxide; max 43°C

P.Br. 29 (1); max 49°C

P.Bk. 30; max 55 °C

Carbon Black; max 63°C

IR REFLECTIVE PIGMENTS

IR REFLECTIVE PIGMENTS

0

10

20

30

40

50

60

70

80

90

100

300 800 1300 1800 2300

Wavelength [nm]

Re

fle

cta

nc

e [

%]

Titaniumdioxide; TSR 85%

Chromium Iron Oxide P.Br. 29 (1); TSR 21%

Chrome Iron Nickel Black Spinel P.Bk.30;TSR 9%

Carbon Black; TSR 5%

Pigment Characteristic: Total Solar Reflectance

TSR – Spectra of different Pigments (20% Pigmentation in Alkyd/Melamine)

slide 13 / 38

Dry film thickness / NIR-Opacity / Influence of Substrate

TSR-value of a P.Br.29 as function of the dry film thickness at a constant

Pigment/Binder ratio over black (absorbing) substrate:

the influence of the substrate is decreasing with increasing dry film thickness

IR REFLECTIVE PIGMENTS

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TSR-value / temperature difference

IR REFLECTIVE PIGMENTS

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NIR-Reflective Pigments for Roof Coating

Did you know white-painted metal roofing has the highest solar reflectance value of any roofing product available and can save you up to 40% of your annual energy bills?

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IR-Reflecting Pigments – Main Application Coil Coating

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IR-Reflecting Pigments – Main Application „Cool Roofs“

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NIR-Reflective Pigments for Roof Coating

IR REFLECTIVE PIGMENTS

ecological contribution of NIR-reflecting Pigments

Interior Heat management by reduced heat flux

(reduced energy consumption for cooling)

Increased lifetime by reduced thermal binder degradation

(Arrhenius-Equation k = A * exp (-Ea/RT) )

(exponential increase of degradation rate in relation to temperature)

Increased lifetime by reduced thermomechanical stress

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Applications-

NIR REFLECTIVE COATINGS

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NIR-Reflecting Coatings

IR Reflective pigments- reflecting CICPs – Complex Inorganic Colored Pigments

Offer a wide range of color shades from yellow to black! They provide an outstanding performance profile: for optimum NIR-reflection superior weather- and light fastness opacity, dispersibility high TSR values highest outdoor durability excellent cost efficiency

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PRODUCT TSR in %PY 53 Nickel Antimony Titanium Yellow 63PBr 24 Chrome Antimony Titanium Yellow 54PBr 24 Chrome Antimony Titanium Yellow 58PG 50 Cobalt Titanate Green 23PBl 28 Cobalt Aluminate Blue 27PBl 28 Cobalt Aluminate Blue 34PBl 36 Cobalt Chromite Blue 24PBr 29 Iron Chromite Brown 22PG 17 Chromium Green-Black 21PBr 35 Iron Chromite Spinel 24PBk 30 Chrome Iron Nickel Black 10

slide 23 / 38

Applications-

Wood Coatings

slide 24 / 38

craters- and blisterscraters- and blisters

Tmax= 60°C Tmax= 90°C

NIR-reflecting pigmentation Conventional pigmentation

Colour difference after 7h irradiation DE = 0,5 DE = 2,2

Wood panels under max. temperature impact

IR-reflecting Colorants – Wood Coating

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cyclic impact on coated spruce panels

4 cycles: 48h conditioning (50% humidity at room temperature)6h IR-Irradiation48h conditioning (50% humidity at room temperature)

NIR-reflecting Pigmentation Conventional Pigmentation

Loss of adhesionand blistering

Loss of adhesionand blistering

DE = 0,2 DE = 1,7

IR-reflecting Colorants – Wood Coating

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Applications-

Composite Thermal Insulation

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Using IR reflecting pigments, the heat build-up on the composite thermal

insulation is reduced, with positive impact on prevention of premature failure

Bri

ck

Pla

ster

Insu

lati

on

≥20°C

80°C

Increased thermal/thermo-

mechanical stress due to higher surface temperatures

Bri

ck

Pla

ster

Insu

lati

on

20°C

60°C

IR-Reflecting Colorants – Composite Thermal Insulation

Exterior coating with IR-reflecting pigment

Exterior coating without IR-reflecting pigment

Composite Thermal Insulation

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Heat-build-up*, Composite thermal insulation, 1/3 STD

25

35

45

55

65

75

85

95

0 5 10 15 20 25 30 35 40 45

Irradiation time [min.]

Tem

per

atu

re [

°C]

PBk 7 - 1/3 STD

PBk 11 - 1/3 STD

PBk 30 - 1/3 STD

PBr 29 - 1/3 STD

measured at the surface w ith IR thermometer

A comparison of IR-reflecting black pigments (PBk 30,PBr 29) with IR absorbing

pigments (PBk 7, PBk 11) shows dramatic differences in heat build-up

D = 15°C

* Measured in a closed box, interior walls Al-foil covered, 150W IR-bulb, electronically dimmed to 60W, 32 cm distance lamp-sample, contactless temperature measurement by IR thermometer, sample 100x200x22 mm

IR-Reflecting Colorants – Composite Thermal Insulation

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Heat-build-up*, Composite thermal insulation, 1/9 STD

25

35

45

55

65

75

85

95

0 5 10 15 20 25 30 35 40 45

Irradiation time [min]

Tem

per

atu

re [

°C]

PBk 7 - 1/9 STD

PBk 11 - 1/9 STD

PBk 30 - 1/9 STD

PBr 29 - 1/9 STD

measured at the surface w ith IR thermometer

At lower proportions of black pigment in 1/9 STD formulations, the heat

build-up of non IR-reflecting pigments still is drastically higher

D = 13°C

IR-Reflecting Colorants – Composite Thermal Insulation

* Measured in a closed box, interior walls Al-foil covered, 150W IR-bulb, electronically dimmed to 60W, 32 cm distance lamp-sample, contactless temperature measurement by IR thermometer, sample 100x200x22 mm

slide 30 / 38

Heat-build-up*, Composite thermal insulation, 1/25 STD

25

35

45

55

65

75

85

95

0 5 10 15 20 25 30 35 40 45

Irradiation time [min]

Tem

per

atu

re [

°C]

PBk 7 - 1/25 STD

PBk 11 - 1/25 STD

PBk 30 - 1/25 STD

PBr 29 - 1/25 STD

measured at the surface w ith IR thermometer

D = 7°C

Even small amounts of non IR-reflecting pigments in a very light 1/25 STD

colour „poison“ the system regarding heat build-up:

PBk 7 and PBk 11 need to be avoided when formulating cool dark and light

colors

IR-Reflecting Colorants – Composite Thermal Insulation

* Measured in a closed box, interior walls Al-foil covered, 150W IR-bulb, electronically dimmed to 60W, 32 cm distance lamp-sample, contactless temperature measurement by IR thermometer, sample 100x200x22 mm

slide 31 / 38

PBk7 PBk30 PBk7 PBk30

Composite thermal insulation with plaster colored with PBk7 and an IR-

reflecting pigment were irradiated with Red/IR-light in a closed box

The surface of the carbon black plaster reached temperatures of >105°C,

causing the insulation layer to degrade in the zone of highest irradiance

IR-Reflecting Colorants – Composite Thermal Insulation

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Measurement of maximum temperatures under realistic conditions

Experimental parameters

Langelsheim, Germany (51.93°N, 10.34°E); sample facing south

9.7.2010; 14:00 o‘clock

38°C maximum air temperature

Thin insulation(20 mm)~15°, south

Thick insulation(110 mm)~45°, south

PBk301/3 STD

PBk71/3 STD

PBr 29 1/9 STD PBk7, 1/9 STD

IR-Reflecting Colorants – Composite Thermal Insulation

slide 33 / 38

PBk7 PBk30PBk7 PBk30

Composite thermal insulation with plaster colored with PBk 7 and IR-reflecting

PBk 30 on professional composite thermal insulation were irradiated with

Red/IR-light in a closed box

The surface of the plaster colored with PBk 7 reached temperatures of max.

102°C, with visibile effects on the structural integrity of the insulation layer in

the zone of highest irradiance, even in this professional set-up

after 5hirradiation !

IR-Reflecting Colorants – Composite Thermal Insulation

slide 34 / 38October 2012

Temperature build-up of composite thermal insulation can be reduced by using IR-

reflecting Pigments

especially PBk7 (Carbon black) and PBk11 (black ironoxide) have to be

avoided, even in low concentrations

Positive effect on heat management expected

Less heat transfer into buildings => less energy consumption for cooling

Longer life-time of composite thermal insulation can be expected with the use of

IR-reflecting pigments in the top coat (coloured plaster, painted plaster)

Less thermal stress/degradation on binder

Less ageing of the insulation layer

Less thermomechanical stress on the interface plaster/insulation layer

Application of darker colours with lower luminosity values becomes possible

IR-Reflecting Colorants – Composite Thermal Insulation

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Thank You for your Attention !!!

David White

Heucotech, Ltd.

99 Newbold Road Fairless Hills, PA 19030-4307

215-736-0712 ext. 142

Davewhite@heubachcolor.com QUESTIONS?