short course: basics of architectural coatings...basics of architectural coatings coating materials...

European Coatings CONFERENCE | Architectural coatings | October 14th, 2014 | Dr. Christian Schaller | 1

Willkommen bei Sto

European Coatings CONFERENCE | Architectural coatings

Short course: Basics of architectural coatings

Düsseldorf, 14 October 2014

Dr. Christian Schaller

E-Mail: [email protected]


Basics of architectural coatings

Who am I?

1990 Abitur am Heinrich-Heine Gymnasium in Ostfildern

1991 - 1997 Chemie Diplomstudium an Universität Stuttgart

1998 - 2001 Promotion am Forschungsinstitut für Pigmente und Lacke in Stuttgart

2002 - 2009 Ciba Spezialitätenchemie in Basel, CH

2009 - 2011 BASF SE – The Chemical Company in Ludwigshafen, D

Juli 2011 Sto AG in Stühlingen, D



Agenda

Market figures

Composition of architectural coatings

Binders: Dispersions, silicones, silikates

Pigments

Additives

Metal coatings

Wood coatings

Facade coatings

Functions of coatings and renders

Optics

Protection: Light stabilization, natural and artificial weathering, biocides,

water managment

Functional facade coatings



Coating materials - Beschichtungsstoffe (ISO 4618:2006)

Coating materials

Paint, varnish Organic render Filler, putty



Application of coatings world wide in 2012

52 % Architectural coatings

7 % Corrosion

protection

17 % Industrial

coatings

2 % Coil

coatings

6 % Wood

coatings

Market size:

35,7 Mio t

96 Bio. € + 8 %

7 % Transportation

coatings

2 % Marine coatings

4 % others

Quelle: Verbandsstatistik

2 % Can Coatings



What are architectural coatings?

Floor

coatings

Metall coatings

e.g. fences,…

Wood coatings

e.g. windows, doors

Roof tile

coatings

Wall, ceiling

coatings

Fassade

paints

Concrete

coatings



What are architectural coatings?

Terms architectural coatings and decorative coatings are used interchangeably.

They include all coatings applied for decorative purposes on new and existing

residential, commercial, industrial or other buildings (wikipedia.org)

Substrates for architectural/decorative coatings

Minerals, stones

Wood

Metals

Elements for architectural/decorative coatings

Walls, ceilings and floors

Doors, window frames, fences, decks

Radiators, tanks

Constructions elements



Architectural Coating (BAM) market in Germany 2012

Total market:

1.73 Mio. €

950.000 t

49 % Interior paints

14 % Facade paint

6 % Primer, impregnations,

sealer

10 % Fillers

9 % Lacquers and varnishes

12 % Organic renders



Composition of

architectural coatings



Coating components

Formulation additives

Performance additives

Additives

1 5 % 1

Binder

Binding

Adhesion

Protection

5 95 % 1

Pigments

Color

Protection

Functionalities

0 30 % 1

Fillers, fibres

Economy

Application

50 60 % 1

Solvent

Carrier for binder

Application

1) % of the solid film



Coating materials - Beschichtungsstoffe (ISO 4618:2006)

Facade paint acc,

1062-1 in %

Organic render acc.

15824 in %

Mineral render acc.

998-1 in %

Aggregate pasty pasty powder

Organic binder 30,0 (disp.) 10,0 (disp.) 2,0 (powder)

Mineral binder - - 16,0

Water 22,0 16,0 -

Dispersion aid 1,0 0,1 -

Wetting agent 0,2 0,1 -

Thickener 0,8 0,1 0,3

Coalescing aid - 0,7

Flame retardant - 8,0 -

Film conservation 1,0 1,0 -

Hydrophobant - 0,5 0,5

Fibres - 0,5 0,2

Fillers 30,0 5,0 -

TiO2 15,0 2,0 1,0

Sand - 45,0 80,0

100,0 100,0 100,0



Binders



Binder technologies for architectural coatings

Façade/wall paints

WB acrylate, styrene-acrylate, VAE dispersions

WB silicones and silicates

Wood coatings

WB acrylate, styrene-acrylate, alkyd, hybrid dispersions

SB alkyds, oils

Metal coatings

WB acrylate, PU dispersions

SB 2K-PUR

Floor coatings

WB/SB 2K-PUR, Epoxies, PUD



What are dispersion?

1 ml Polymer dispersion contains

ca. 100.000.000.000.000 particles

1 macromolecule contains between

1.000 and 10.000

monomer units

1 particle contains up to 10.000

macromolecules

Dispersion is a system in which particles are dispersed in a continuous phase of a

different composition (or state). A dispersion is classified in a number of different ways,

including how large the particles are in relation to the particles of the continuous phase,

whether or not precipitation occurs ….. (wikipedia.org)



Binder – technologies used for façades

Dispersions

Acrylate for low PVC exterior paints/plasters

Color/weather stability, reduced dirt pickup

Styrene acrylate for standard exterior/interior paints

Universal, price

VAE - ethylene vinyl acetate (EVA) for interior paints

VOC-free, abrasion resistance

Silicones

Silicone modified (resin/oil) coatings for exterior paints/plasters

Hydrophobicity, weather stability

Silicates

Silicates for exterior/interior paints/plasters

Mineral system, ecological



Market share of facade paint binder chemistry in Europe



Market share of facade paint binder chemistry in Germany



Pigments



Pigments and extender

Besides binder solvents and additives pigments and extender (filler)

are used to introduce

Color

Hiding power

Special optical effects

Functional properties e.g. sandability, hardness,….

Tasks of pigments Requirements for

pigments and extenders

Special tasks of extender

• Selective absorption

• Light scattering

• Optical effects by

oriented reflection or

orientation

• UV protection

• Corrosion protection

• Dispersibility

• Unsoluble

• Light fast and weather

resistance

• Chemical resistance

• Physiological compatible

• „Filling“with skeletal

material

• Sandability

• Improvement of

mechanical and technical

coating properties



Pigments

DIN 55943:

inorganic or organic, chromatic or achromatic colouring

agents that are practically insoluble in the application medium

Organic pigments

+ Broad range of colors

+ Brilliant chromatic colors

+ High tint strength

- Durability

- Hiding powder

Inorganic pigments

+ Good durability

+ Good hiding

+ Good rheology

- Low tint strength

- Low brilliance

- Small range of colors

- Low chemical stability

http://www.google.de/imgres?imgurl=http://www.agnihotra.ch/wp-content/2008/10/pigmente.jpg&imgrefurl=http://www.agnihotra.ch/?tag=pigment&usg=__NFmQzcI6NS8F04FuNyslhb-SOMQ=&h=600&w=800&sz=206&hl=de&start=1&zoom=1&tbnid=R52_70fDcDbOhM:&tbnh=107&tbnw=143&ei=Qr-yTq3WNouVOsLo1OYB&prev=/search?q=pigmente&um=1&hl=de&sa=N&tbm=isch&um=1&itbs=1

http://www.google.de/imgres?imgurl=http://maltechnikwerkstatt.files.wordpress.com/2009/05/pigmente02.jpg&imgrefurl=http://maltechnikwerkstatt.wordpress.com/&usg=__m1MOO8z8gDyl8mweaheLunjFlDA=&h=480&w=640&sz=121&hl=de&start=47&zoom=1&tbnid=dg5Prb2ZGJ6dpM:&tbnh=103&tbnw=137&ei=iL-yTs7LH4OAOvuGteEB&prev=/search?q=pigmente&start=42&um=1&hl=de&sa=N&tbm=isch&um=1&itbs=1

http://www.google.de/imgres?imgurl=http://chs.tanatexchemicals.com/s_producten/media/upload/pages/image/FIL30944.jpg&imgrefurl=http://chs.tanatexchemicals.com/de/anwendungen/lackeundfarbstoffe&usg=__eiwND0mBl-pRpkOjwRCrRMu5LzI=&h=216&w=324&sz=24&hl=de&start=14&zoom=1&tbnid=tvAVHkXwkEh3VM:&tbnh=79&tbnw=118&ei=WsCyToyyH7Ta4QTbw_iABA&prev=/search?q=anorganische+pigmente&um=1&hl=de&sa=N&tbm=isch&um=1&itbs=1



Titanium dioxide TiO2

Primary pigment for paints and coatings but expensive

TiO2 key raw material for façade coatings essential for:

Quality (opacity, durability, color fastness…)

Costs (up to 40 % of the formula costs are caused by TiO2)

Usually coated with inorganic oxides (Al, Si, Zn, Zr) to

reduce photocatalytic effects

improve weather stability

aid dispersibility

Strategies for efficient and economic use

Stabilization

Separation

Spacing

Substitution


TiO2 offers highest performance of any material for opacity and whiteness

TiO2 dispersion vs relative hiding (PVC of paint 20 %)


Why TiO2?

Source: DuPont Technologies

From Mie theory: rutile TiO2 vs. ZnO

At equal concentration, 6 times greater

thickness is needed to achieve same opacity

Efficiency of TiO2 in coating depends upon:

Primary particle size TiO2 producer

Amount of aggregation TiO2 producer

Dispersion quality in film paint producer



Pigment volume concentration (PVC)

low PVC

(< CPVC)

CPVC high PVC

(> CPVC)

PVC

Permeability

Gloss

Blistering

Adhesion

Varnish

Enamel paintFacade paints

Flat interior paintsSheen interior paints

Silicate paints

Silicone paints

Elastomeric paints



Additives



Additives

Additives (lat. additivum „to add“, „attached““), additional components incorporated into a

coating to improve both processing of raw liquid system and/or improve application

properties or influence dry coatings performance (wikipedia.org)


Processing

Storage

Application


Coating performance

Coating properties

Additional functionality




Tensides

Polyacrylates/

Polyphospates

Wetting /

Dispersing

agents

Rheology

modifiers

Clays

Cellulosics

ASE, HASE

HEUR

Slip & leveling

agents

Silicones

Fluorocarbons

Defoamers

Mineral oils

Silicones

Polymers

Other additives

Compatibilizers

Humactants




Biocides

Film protection

IPBC, OIT….

In can

preservation

BIT, MIT, CIT,…

UV absorber

BP, BTZ, HPT

HALS

Light stabilizer Antioxidants

Hindered

phenolics

Phosphites

Thiosynergists

Hydrophobants

Silicones

Fluorocarbons

Added

functionality

IR reflection

Electric

Magnetic

Corrosion



Influence of light on coatings



Light and thermal stabilization of coatings

Automotive Architectural PlasticsWoodIndustrial



…and other painfull consequences….



Definition of UV light according DIN 5031

Ultraviolett (UV) light damages

organic materials (e.g.

coatings....)

Most radiation (l < 290 nm) is

absorbed by ozone in

atmosphere

5 - 7 % of UV light reaching earth

surface

UV-A: 315 - 380 nm

UV-B: 280 - 315 nm

UV-C: 100 - 280 nm

~ ~

l / nm100 200 300 400 500 600 700 800 900 1000 106

UV-B UV-A VISUV-C IR-A / IR-C

VIS: 380 - 780 nm

Visible (VIS) light responsible

for photo-synthesys

„life on earth“

IR-A/C: 800 - 4000 nm

Infra red (IR)

heat radiation



Interactions of light with materials

Reflection

22

22

k)1n(

k)1n(R

Degree of Reflection:

R Reflection

n Refractive Index

k Absorption coefficient

„Mirror Effect“

Mie theorie:

02

2

4

6

S I2n

1nDN~I

l

Scattering

IS Scattered light

I0 Incidential light

N Number of particles

D Particle diameter

Wavelenght of light

n Refractive index

Scattering

„White Effect“

Transmittance

dc

0

eI

IT

I Transmitted light

I 0 Incidential light

„Color of liquids“

Absorption

dcT

1logA 10

Lambert-Beer law: A Absorbance

T Transmission

Extinction coefficient

c Concentration

d Film/layer thickness

„Color of surfaces“



Light absorbance and subsequent reactions

P-H

R •

P•

O2

ROO •

POO •

P-HROOH

POOH

RO• + •OH

PO• + •OH

P-H

CHh • n

CH*

CH: Chromophore

= UV absorbing group

UV absorber

UV absorber (UVA):

Absorption (filter effect) of

damaging UV light before

exited state CH* is formed

Peroxide decomposers:

Deactivation of

peroxides

Peroxide

decomposers

Radical scavengers

Trapping of radicals before

subsequent reactions leading to

degradation

Radical-

scavenger

auto-

catalytic



Mode of actions of light stabilizers

HALS: Avoid surface defects

HALS: Avoid surface defects and protect pigments

UVA:Light protection by pigments(Absorption/scattering/reflexion)

Surface not properly protected No additional UVA needed

UVA:Optimal performance at higherconcentration (c), film thickness (d) and extinction ()

Surface not properly protected

HALS

Synergism with UVA and HALS Only HALS for opaque Systems

Clear coatings

d

UV Absorber

dceT

HALS

Pigmented coatings



Natural and artificial weathering



Why do we need weathering tests?

Weathering tests can be performed during every step in development and

production process

Materials can be subjected to quality inspection to get insights into interactions

with solar radiation, heat and water

to evaluate the performance of coatings (quality control)

to optimize performance of coatings

to predict protective/aesthetical properties



Variables for natural weathering

Location (world wide weathering….)

Orientation (north, south,….)

Sample racks with differing inclinations (5°, 45°, 90°)

Open or closed rack/boxes (air cooling from back)

With and without glass cover panels (interior vs exterior)

Fresnel mirrors can concentrate sunlight on samples (EMMA®, EMMAQUA®)

Sensors and mechanical drives can track sun’s path to maximize radiant exposure

Most important: you need to know what you want to see



Artificial weathering methods



Fluorescence light vs xenon light exposure

Pigment: P.O. 34 in AM system

Exposure: 200 h

Light fastness

ISO 11341/C

Xe-WOM CAM 0

Weather fastness

ISO 11341/A

Xe-WOM CAM 7

Weather fastness

SAE J1960

Xe-WOM CAM 180

UV-A 8 h / 4 h

ASTM G154-00

UV-B 8 h / 4 h

ASTM G154-00



Correlation natural vs artificial exposure

UV-A and UV-B exposure

“Quick and dirty” tests for relative comparison between materials (binders)

under specific conditions

Fluorescence devices are relatively cheap

Not suitable for colored substrates

No comparison to service life performance or correlation to outdoor exposures

Xenon exposure

Suitable for clear and colored substrates

Correlation to natural exposure depending on system and climatic conditions

12 month Florida, US 2000 h CAM 7 (validated for automotive systems)

12 month Stühlingen, CH 1000 h CAM 7 (validated for wood coatings)

Xenon devices are expensive and need high maintenance



Natural vs artificial weathering

Natural/outdoor exposure

Realistic conditions (light, dirt, algea,…)

No size limitations

Long exposure time/limited acceleration

Reproducibility of climate and seasons

Artifical weathering

Reproducibility and repeatability

Acceleration possible

Test can run continuously

Only light effects

Size limitation

Correlation not always given



Limitations of artificial weathering

Real life

21 days

@ 35-40 °C

Accelerated

3 min

@ 100 °C



Biocides



Microbiological attack on facades

Fungi Algea

Conditions • H2O

• Nutrients

• H2O

• Light

• CO2

Substrate • Wet • Wet

Facade • Optik • Optik



Influences of microbiological attack

ConstructionEnvironment Climate Material

Air pollution

Orientation

Surface/splash

water

……

River valley

Lake area

Fog area

Forest edge

Seasons

…..

Overhanging roof

Attic

Building height

……

Cracks

Water uptake

Substrate

Biocides

Food

…..



Biocides

Biocide is a chemical substance which can deter, render harmless, or exert a controlling

effect on any harmful organism by chemical or biological means. Biocides are commonly

used in medicine, agriculture, forestry, and industry (wikipedia.org)

European Community Classification

Biocidal Products Directive 98/8/EC (BPD), classification of biocides, is broken down into

4 main groups with 23 product types (i.e. application categories)

MAIN GROUP 1: Disinfectants and general biocidal products

MAIN GROUP 2: Preservatives

Product-type 6: In-can preservatives

Product-type 7: Film preservatives

Product-type 8: Wood preservatives

MAIN GROUP 3: Pest control

MAIN GROUP 4: Other biocidal products


Functionality/Efficency


Influencing parameters on durability of biocides (actives) in coatings

Water

Rain (duration/intensity)

Dew

Climate / °C

Night/day...

Seasons…

Light/radiation

UV/VIS

IR

Wind

Direction

Intensity

Coating

Water management

Durability

Biocide

Compatibility

Solubility

Material parameters Leaching

Chemical/biological

degradation

Evaporation

UV degradation

Ecotoxicity Biocidal Product Directive (BPD) 98/8/EC (PT 7 )

Risk assesment: emission scenario documents PT 7

Predicted Environmental Concentration (PEC)



Substrates



Substrates for architectural coatings

Stone like (mineral) substrates

Concrete

Mineral plasters (EIFS)

Fairfaced/exposed brickwork

Natural stone

Metal

Iron and iron alloys

Aluminium

Zinc

Copper and Copper Alloys

Wood

Natural wood

Wood composite material

Others

Wallpaper

Boards (gypsum, fibre cement,…)



Metals



Metal for architectural application

Architectural metals used in buildings and structures

comprise several distinctive metallic materials for

structural and decorative purposes

Iron and iron alloys (structural: columns, fronts, domes

and light courts; decorative: stairs, elevators, verandas,

balconies, railings, fences, …)

Aluminium (constructive as well as decorative features:

entrances, elevator doors, ornamental trim,…)

Zinc (roofing, gutter…)

Copper and Copper Alloys (roofing,…)

Metal need to be protected from damaging impact of

environment

Most metal need corrosion protection due to coatings



Basics of corrosion

Corrosion derives from Latin and means an intensive gnawing

A process being destroyed by reacting chemically with its

environment

Corrosion is gradual destruction of substrate, (e.g. metal like

iron, zinc, etc.) by electro chemical oxidation reaction with

environment - reaction of metals with oxygen and water

Corrosion not only loss of decorative appeal - if not prevented it

shorten lifetime of objects

air

water

metal

Anode area

Cathode area

rust

Fe2+ + 2 OH- → Fe(OH)2

2 Fe → 2 Fe2+ + 4 e-

O2 + 4 e- + H2O → 4 OH-

O2



Film formation, barrier properties and anti corrosion performance

Coherent and defect-free polymer film is basic requirement for effective

protection of metal surface

metal

interstices (as well as film defects) as pathways

for migration of oxygen, water and ions and …

… when they reach polymer-metal

interphase electrochemical reactions will

take place, causing rust

Scratches, pores and zones of paint with reduced crosslinking density must be avoided

Delamination can be delayed by designing binders with better film forming

and barrier properties, adhesion to metal and pigment distribution



Powder coatings



Use of powder coatings for architectural applications

New Juventus Turin stadium, Turin Italy

Hôtel du département des Bouches-du-Rhône

Marseille, France

Petronas Twin Towers, KL, Malaysia

Powder coatings are used for

metall construction elements and

facade parts



Wood



Wood a unique construction material

There are different applications

Interior (parquet, furniture, …)

Exterior (timber, joinery, …)

There are different paint qualities

Water-borne, solvent-borne, UV,…

Alkydes, acrylics, 2K PUR, NC…

Film forming, low film forming, penetrating…

Clear, semi-transparent, opaque…

There are a large choice of wood species

Softwood, hardwood

Pale/colorless, colored wood

Modified wood, composites

……but there is no universal solution for wood….



What is Wood? Structural substances

OH

OH

O

OH

OO

OHO

O

OO

OHO

OHOHO OH

OO

OH

OH

CH2OH

H3CO

CH2OH

HOH2C

Pentose

Hexose

OH

OH

O

OH

OO

OHO

O

OO

OHO

OHOHO OH

OO

OH

OH

CH2OH

H3CO

CH2OH

HOH2C

Pentose

Hexose

25 % - 30 % Hemicellulose

Branched low-molecular weight Hexose/Pentose polymers

„Glue“ among cellulose structures and lignin

O

O

O

OH

O

OH

OH

O

O

OHOH

OH

O

O

O

OH

O

OH

O

OH

O

O

O

O

OH

O

O

O

O

O

OH

OO

OH

MeO MeO

MeO

MeO

MeO

MeO

OMe

MeO

MeO

OMe

OMe

OH

MeO

MeO

OMe

20 % - 30 % Lignin (lignocellulosic material)

3D phenylpropanol polymer

Structural support and adhesive material in plants

Lignin is the „cement“ for wood

40 % - 45 % Cellulose

Linear D-Glucose polymer (200.000 to >Mio.)

Cellulose is the „skeleton“ of wood

OHO

OO

OHO

CH2OH

OHOH

O

O

OO

OHO

CH2OH

OHOH

OHCH2OH CH2OHD-Glucose

41

-1,4-Glucan

OHO

OO

OHO

CH2OH

OHOH

O

O

OO

OHO

CH2OH

OHOH

OHCH2OH CH2OHD-Glucose

41

41

-1,4-Glucan

Lignin responsible for photo-oxidation

OH groups of cellulosics cause water sensitivity



What is Wood? Non structural substances

Organic components („extractives“ )

Some are highly colored and chemically active:

Tannins act against microbes, pathogens brown staining

Resins act as biocide migration from knots

Terpenes act as bactericide, fungicide...

Essential oils, waxes, fatty acid ester….

Inorganic components („ashes“)

K, Ca, Mg-salts; Fe, Mn, B cations...

Colored extractives cause darkening/brown staining by

migration to the substrate surface

Chromophores from extractives can be bleached-out

by photo-oxidation



Wood protection strategies

Plywood

Bulk wood

WPC

MDF

Modified

wood

Constructive protection

Wood assembly

Chemical treatment

Industrial treatment of wood

Impregnation/film protection

Light protection

Pigmentetd coatings

Light stabilizer

Protection from water

Coating

Hydropobic impregnation



Stones



Mineral substrates for exterior and interior architectural coatings

Substrates for interior wall paints

Mineral/organic renders

Wall papers

Gypsum boards

Substrates for exterior façade paints

EIFS (Exterior insulation and finishing system)

Mineral/organic renders

Concrete

Specifications for coatings

DIN EN 13 300 Classifies aqueous coatings for decoration and

protection of new and existing, coated and uncoated walls

and ceilings for interior applications

DIN EN 1062-1 Paints and varnishes - Coating materials and coating

systems for exterior masonry and concrete - Part 1:

Classification; German version EN 1062-1:1996

DIN EN 15824 Specifications for external renders and internal plasters

based on organic binders



Concrete

Concrete is composite construction material composed of

Aggregate (coarse gravels or crushed rocks e.g. limestone, or granite, mixed

with fine aggregate e.g. sand)

Cement (Portland cement, and other materials e.g. fly ash and slag cement)

Various chemical admixtures to achieve varied properties

Water

Concrete has relatively high compressive strength,

but much lower tensile strength

Today ferroconcrete is used with following

advantages

Chemical compatibility: alkalinity of concrete protect

steel from corrosion

Force transmission due to composite nature

Similar temperature coefficient



Properties of concrete

Alkalinity of ferroconcrete is key for corrosion protection of steel

reinforcement

Natural influences (CO2, acidic rain,..) reduces alkalinity and so corrosion

protection

Requirements for concrete coatings

Alkali resistance

Protection against water

Diffusion resistance against CO2; sd CO2 > 50 m

Crack bridging

Ca(OH)2 + CO2 + H2O CaCO3 + H2O

Hydrated limestone limestone

pH > 12 pH < 9,5

Carbonization



Exterior insulation and finishing system (EIFS)

Masonry

Exterior insulation and finishing system (EIFS) is a type of building exterior wall

cladding system that provides exterior walls with an insulated finished surface and

waterproofing in an integrated composite material system (wikipedia.org)

Insulation material

Reinforcement

Top coat render acc

(DIN EN 15824/998-1)

+

Facade paint

(DIN EN 1062-1)

Base coat

Thermal conductivity (λ) in W/mK:

Material l in W/mK

VIP 0,004 – 0,008

Aerogel 0,013 - 0,018

PUR 0,024 - 0,035

EPS/XPS 0,032 - 0,040

Mineral woll 0,030 - 0,050

Wood fibre boards 0,040 - 0,052

Cork 0,040 – 0,050



Requirements for ETICS

ETAG 004: GUIDELINE FOR EUROPEAN TECHNICAL APPROVAL

of EXTERNAL THERMAL INSULATION COMPOSITE SYSTEMS

WITH RENDERING

Water absorption (Capillary test) (5.1.3.1)

Hygrothermal behavior (5.1.3.2.1)

Freeze/thaw behavior (5.1.3.2.2)

Impact resistance, hard body impact (5.1.3.3)

Water vapour permeability (5.1.3.4, DIN EN 12 086)

Bond strength

between basecoat and insulation (5.1.4.1.1.)

between adhesive and substrate (5.1.4.1.2.)

between adhesive and insulation (5.1.4.1.3. )

Bond strength after aging (5.1.7.1.1.+5.1.7.1.2.)



Specifications for facade coatings

DIN EN 1062-1: Paints and varnishes - Coating materials and

coating systems for exterior masonry and concrete - Part 1:

Classification; German version EN 1062-1:1996

Optical properties (gloss)

Mechanical properties (crack bridging)

Permeability for CO2

Water permeability

Water vapor permeability



Specifications for renders and plasters

DIN EN 15824: Specifications for external renders and internal

plasters based on organic binders; German version EN

15824:2009

Water vapor permeability (for renders) (EN ISO 7783-2)

Water absorption (for renders) (EN 1062-3)

Adhesion (for renders and plasters)

Durability (only for renders)

Thermal conductivity

Reaction to fire (for renders and plasters)



Interior architectural coatings

DIN EN 13300: Paints and varnishes - water-borne coating

materials and coating systems for interior walls and ceilings

– Classification; German version EN 13300:2001 + AC:2002

Wet scrub restistance (WSR)

Hiding power, contrast ratio

Gloss

Grain size, granularity



Functions of architectural coatings

Basic functions Protective functions Additional functionalities

• Color/aesthetics • Water balance

• Exterior durability

• Color stability

• Resistance against biological

contamination

• Low dirt pick-up

• Self cleaning coatings (Lotus®-Effect)

• Dirt-reppeling, low dirt-pick up coatings

• Air cleaning / photocatalytic coatings

• Heat management, heat

absorbing/reflecting coatings

• Anti-freeze / icing / fooging coatings

• Light emitting coatings

• Self-healing coatings

• Conducting, magnetic, electric

coatings……



Optical and aesthetical apperance of buildings



Protective functions of architectural coatings

Water

Precipitation (rain, snow,..)

Air humidity (dew, fog,…)

Temperatur

Natural (day, night, climate,…)

Artificial (fire,…)

Radiation

UV and visible light

Infrared

Air pollution

Mineral (dust,…)

Organic (NOx, rust,…)

Bioorganism

Microorganism (fungi, algea..)

Animals (termites,…)

Mechanic

Exterior (hail, balls,….)

Interior (insulation loss,

swelling,….)



Color stability - Surfactant leaching and efflorescence

Efflorescence

Migration and crystalization

of water soluble salt on surface

Surfactant leaching /Abläufer

Washing out of water soluble

components from coating

Influencing factors

Formulation components

Application (Film built, drying

conditions…)

How to avoid it?

Optimize formulation

Reduce water soluble components

Follow recommended application



Color and appearance – color stability

UV stability of coatings

Color fading

Surface defects

Erosion of surface

Influencing factors

UV stability of pigments,

binders etc.

Weather conditions

Orientation

How to avoid it?

Optimize formulation (PVC….)

Use more durable products



Measures against microbiological attack of facade coatings

Driving rain

Splash/surface

water

Constructive

protection

Condensation

H2O vapour

Constructive protection

Avoid direct water contact (driving rain/splash water)

Try to keep facade dry

Optimize water balance of facade coatings

Allow quick re-dry

Low liquid water permeability (w value)

High water vapour diffusion (sd value)

Play with hydrophobicity and hydrophilicity

Optimize formulation

Adjust formulation in terms of PVC,…

Reduction of potential food source

Use of modern biocidal products

Actives with improved durability in coatings

Encapsulated actives with reduced

solubility/leaching rates



Parameters to describe water management

Water permeability (Wasserdurchlässigkeitsrate)

w value in [kg/(m2•h0,5)]

Water vapour diffusion resistance factor

(Wasserdampf-Diffusionswiderstandszahl)

µ [-]

Water vapour diffusion equivalent air layer thickness

(Wasserdampfdiffusionsäquivalente Luftschichtdicke)

Sd value in [m]

Water-vapour transmission rate (permeability)

(Wasserdampf-Diffusionsstromdichte)

V in [g/m²d]



Water management: hydrophilicity vs hydrophobicity

Today there are two worlds

Hydrophobic paints like e.g. Lotusan®

self-cleaning due to super hydrophobic and micro

structured surface

rain runs off

long drying time after dewing

Hydrophilic paints like e.g. ThermoSan

(Nano-Quarz-Gitter-Technology)

fast surface drying

water uptake in film

Super-

hydrophobic

(Lotusan®)

hydrophobic

(Silicon paint)

hydrophilic

(dispersion paint)

Paint Contac angel

Super-hydrophilic < 10°

hydrophilic 10° - 90°

hydrophobic 90 - 140°

Super-hydrophobic > 140°



Functional facade coatings



Self-cleaning coatings - The Lotus®-Effect

The „Lotus-Effect ®“ is the technical

translation of the lotus leave mechanism

of action

Double functionality of mechanism of action

Function 1:

Micro structured surface

Contact area for dirt and water is

extremly reduced

Function 2:

Super hydrophobic surface

Raindrops drip off and rip of dirt

particles



Heat management with NIR technology

Morgens halb zehn in Deutschland...... 09:30 pm somewhere in Germany......

Sun light is energy riche radiation

Visual aspect

Thermographic picture



Benefits and potential use of NIR technology

Thermal picture of Atlanta/Georgie

http://earthobservatory.nasa.gov/Features/GreenRoof/

Dark colors can reach up to 80 °C under direct sun

irradiation

Heat sensitive substrates can show problems

Today colors with HBW < 20 are not recommended for

EPS based Exterior insulation and finishing system

(EIFS)

Colors based on NIR technology can close this gap

Full color freedom on EPS based EIFS

Energy safeing due to reduced use of air cons

Reduction of urban-heat-island effect (UHI)

~ 50 °C~ 65 °C

Standard paint NIR technology



Air cleaning paints

Air pollutants

substances (smoke,

NOx) hit color surface

Result is improved air

quality

Air cleaning paints can be used to

Improve room air quality in inhabitated space (e.g. against smoke, odours)

Reduces air pollution in urban life (e.g. streets, tunnels, subways,…)

Light activates photocatalytic paint

Formation of active oxygen

Decomposition of pollutants at surface


Thank you for your attention

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