©2009 Cytec Industries Inc. All rights reserved.

Johnny Zhang Asia Pacific TS&D Manager for Liquid Coating Resins

Cytec Surface Specialties 章志源

液体涂料树脂 亚太地区技术服务与发展经理 氰特表面技术

POLYURETHANE - DISPERSIONS

Dr. Ulrike Kuttler Global Application Development Manager CYTEC Austria

Pioneering Sustainable Change

1. PUD „Basics“ Basic chemistry Raw materials Schematic production process Different production procedures Structure related properties „Take aways“ Basics

2. Structure – property relationship, advanced knowledge

Influence of soft segments Influence of molecular weight

3. Application examples and formulation recommendations 4. Trends

Agenda

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Soft - Segments Hard - Segments

In the synthesis of PU dispersions Polyisocyanates (hard segments) and Polyols (soft segments) are co- reacted in a polyaddition reaction.

Structure of PU- dispersions

OH-Polyester

OH-Alkyd OH-Polyether OH- Acrylate

OH- Polycarbonate

Polyisocyanate (TDI, IPDI,

TMXDI...) Diol

Dimethylolpropionic acid (Amine)

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N N

NO O

O(CH2)6 OCN

(CH2)6 OCN

(CH2)6O C N

(CH2)6O C N N N N

O O

H H(CH2)6 OCN

(CH2)6 OCN

O C N

OCN

CH3

CH3

CH3

OCNO C N

(CH2)6O C N N N

O

O

(CH2)6 OCN

(CH2)6O C N OCN

Typical Hard - Segments

Hexamethylen diisocyanate (HDI)

Isocyanurate

Biuret

Urethdion

Isophorondiisocyanat (IPDI) Dicyclohexylmethandiisocyanat (Desmodur W)

aliphatic / cycloaliphatic

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CH3

OCNO C N

OCN

OCN

OCNO C N

CH3

OCN

OCN Toluylendiisocyanate (TDI)

Diphenylmethan-diisocyanate (MDI)

Typical Hard - Segments

aromatic

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Soft-Segments Hard-Segments

Co-reacting Soft- and Hard-Segments

Neutralization (amines or strong bases)

Dispersing in water

Chain elongation Chain stopping

Schematic Production Process for PUD‘s

Different production procedures for PUD‘s

„ACETONE“ PROCESS 1. Polyaddition (i.e. co- reaction of soft segments with Polyisocyanates and a

hydrophilic acid component) as well as the chain extension step (with Di- oder Polyamines) is run in Acetone (homogeneous phase) (instead of Acetone solvents like e.g. MEK, MIBK, THF are also suitable)

2. after the neutralization- and dispersion step the Acetone is distilled off

Advantages:

• very universal • viscosity during synthesis easy to control

Disadvantages:

• complex and expensive • residual solvent in the resin • Process not sustainable • Unfavorable yield

Different production procedures for PUD‘s

„MELT“ PROCESS 1. Polyaddition (i.e. co- reaction of soft segments with Polyisocyanates and a

hydrophilic acid component) is run WITHOUT any solvent (in a melt)

2. A potential chain extension step is run AFTER the neutralization and dispersion step (i.e. in water)

Advantages:

• NO residual solvent • good yield • no „solvent waste“

Disadvantages:

• Tricky process (very high viscosities) • Process not suitable for all the different PUD- chemistries

„SOLVENT“ PROCESS 1. Polyaddition (i.e. co- reaction of soft segments with Polyisocyanates and a

hydrophilic acid component) is run WITH solvent (NMP/NEP are the most common ones)

2. A potential chain extension step is run AFTER the neutralization and dispersion step (i.e. in water)

Advantages:

• very universal • viscosity during synthesis easy to control

Disadvantages:

• Resin may contain quite high amounts of solvent • Toxicology and price of NMP (NEP?)

Different production procedures for PUD‘s

„MONOMER“ PROCESS 1. Polyaddition (i.e. co- reaction of soft segments with Polyisocyanates and a

hydrophilic acid component) is run in acrylic monomers (acrylic /methacrylic acid and esters thereof) that act as „solvent“

2. A potential chain extension step is run AFTER the neutralization and dispersion step (i.e. in water)

3. Radical polymerization of the acrylic monomers yields a solvent free, acrylic modified PUD (graft polymer)

Advantages:

• NO residual solvent • good yield • no „solvent waste“

Disadvantages:

• Smart but tricky process • Only for acrylic modified PUDs (graft polymers)

Different production procedures for PUD‘s

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Hard - Segment „ net-points“ Soft - Segment flexibility

Film Morphology

Soft- and Hard- Segments within the polymer are leading to a „structure of domains“. This special stucture is creating the well known tough-elastic behaviour of PUD based coatings (even at low temperatures!)

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PU- dispersions - Structure properties

O

R NH C NH R N H C O R‘

O

R

Urea Urethane

Urea- as well as Urethane groups have a strong dipole moment. This is causing strong interactions with the surface of substrates excellent adhesion to “difficult substrates” like e.g. plastics Moreover this dipole moment is causing strong intermolecular forces (cohesion) outstanding mechanical properties and elasticity

1. PUD‘s are produced by a polyaddition- reaction of soft segments (OH- group containing pre- polymers) with Polyisocyanates (hard segments) and a hydrophilic acid component

2. The different production procedures for PUD- resins are tricky and complex

3. The majority of the hard segments (Polyisocyanates) as well as many soft segments (OH- Polycarbonates, OH- Polyethers,….) are high price raw materials leading to PUD‘s with elevated price level

4. The different production procedures for PUD- resins are tricky and complex

5. The outstanding and quite often unique properties of PUD‘s like e.g.

• adhesion to critical substrates • outstanding mechanical properties • excellent elasticity and abrasion resistance • tough elastic behaviour even at low temperatures

make PUD‘s your first choice for many paint applications!

PUD Basics – The „Take Aways“

Structure – Property Relationship

Advanced Knowledge

PU- dispersions - Soft Segments

OH- Polyester OH- Alkyd OH- Polyether OH- Polyacrylate OH- Polycarbonate

Advantage

Very good appearance V. good mech. properties Good body Good substrate penetration Low viscosity Hydrolytic stability Quick drying Outdoor durability Hydrolytic stability Outdoor durability

Disadvantage

Hydrolytic stability Yellowing, outdoor durability Hydrolytic stability Poor light- and thermo stability Stability against oxidants Price

PU- dispersions - the molecular weight

PUD‘s with low / medium molecular weight („chain stopped“ grades) designed for 2 pack applications (crosslinking with Polyisocyanates) Advantages:

• Good leveling (due to slow physical drying) • Good degassing • Good pigment wetting • Excellent chemical- and solvent resistance properties • Can be formulated with little to no solvents

Disadvantages:

• Need crosslinker (Polyisocyanat) • More complicated handling • potlife • Price (expensive Polyisocyanate)

PU- dispersions - the molecular weight

PUD‘s with high / very high molecular weight („chain extended“ grades) designed for 1 pack applications (crosslinking with Polyisocyanates is possible) Advantages:

• quick physical drying • Excellent orientation of metalic pigments (bright metalic effect!) • Outstanding elasticity and mechanical properties • Does not need crosslinker (Polyisocyanat) • Easy handling (1 pack!) • No potlife

Disadvantages:

• weak pigment wetting • weak chemical- and solvent resistance properties • Poor leveling (due to quick physical drying) • should be formulated with solvents

Application examples and

formulation recommendations

PU- dispersions - preferred fields of application

SUBSTRATE Plastic Metal Wood

LAYER Primer Basecoat Monocoat Primer Surfacer Basecoat Primer Clearcoat

MAIN BENEFIT Adhesion, mech. Properties Adhesion, metalic effect, mech. properties Adhesion, stone chip properties Adhesion, metalic effect, mech. properties Penetration, adhesion Abrasion resistance, „Anfeuerung“

w/b 1 Pack Primer for Plastic

Black, conductive 1 Pack Primer based on Daotan TW 6450 excellent adhesion to plastic (ABS, PC) and excellent humidity resistance Application: e.g. Primer for plastic bumper (auto OEM)

34,3g Daotan TW 6450/30WA 2,5g Dimethylethanol amine 10% in water 2,3g Butyl glycol 0,2g Defoamer 0,3g Additol VXW 6208 (wetting and dispersing agent) 4,5g Bentone EW 3% solution 13,1g Kronos 2310 2,3g Talcum AT Extra 1,6g conductive Carbon Black Premix and grind in bead mill to requested fineness 9,2g de- ionized Water 0,3g Defoamer 0,3g Additol VXW 6503 (substrate wetting agent) 11,7g Butyl glycol 17,4g de- ionized Water (for adjusting to spraying viscosity) 100,0g

Spraying viscosity: 35-40s DIN 4 Curing: 10 min flash off + 10 min 80°C Overcoat with s/b or w/b Basecoat

w/b 2 Pack Primer for Plastic

Black, conductive 2 Pack Primer based on Daotan TW 6425 excellent adhesion to plastic (ABS, PC) and excellent humidity and chemical resistance Application: e.g. Primer for plastic bumper (auto OEM)

Pack A: 31,1g Daotan TW 6425/40WA 3,0g Dimethylethanol amine 10% in water 2,7g Butyl glycol 0,3g Defoamer 0,4g Additol VXW 6208 (wetting and dispersing agent) 5,4g Bentone EW 3% solution 15,8g Kronos 2310 2,8g Talcum AT Extra 2,0g conductive Carbon Black 5,8g de- ionized Water Premix and grind in bead mill to requested fineness 11,0g de- ionized Water 0,4g Defoamer 0,3g Additol VXW 6503 (substrate wetting agent) 14,2g Butyl glycol 95,2g

w/b 2 Pack Primer for Plastic

Black, conductive 2 Pack Primer based on Daotan TW 6425 excellent adhesion to plastic (ABS, PC) and excellent humidity and chemical resistance Application: e.g. Primer for plastic bumper (auto OEM)

Pack B: 3,3g Desmodur N 3300 0,7g Butyl acetate 0,8g Solventnaphtha 150/180 4,8g Blend Pack A and Pack B shortly before processing and homogenize well Spraying viscosity: approx. 25s, DIN 4 Curing: 10 min flash off + 10 min 80°C Overcoat with s/b or w/b Basecoat

w/b Basecoat for Plastic

White Basecoat based on Daotan TW 1236 excellent adhesion to plastic (ABS, PC) and excellent humidity resistance Application: e.g. plastic parts for motorbikes

41,2g Daotan VTW 1236/40WANEP 24,8g Kronos 2310 1,3g Additol VXW 6374 (wetting and dispersing agent) 0,3g Surfynol 104/50EG (multi purpose additive) 7,1g Butyl glycol 1,4g Butyl diglycol 11,3g de- ionized Water Premix and grind in bead mill to requested fineness 0,3g Additol VXW 5907 (defoamer) 1,4g Shellsol T 10,9g de- ionized Water (for adjusting to spraying viscosity) 100,0g Spraying viscosity: 35-40s DIN 4 Curing: 10 min flash off + 10 min 80°C Overcoat with s/b 2K Clearcoat

w/b 2 Pack Monocoat for Plastic

Silver metalic 2 Pack Monocoat based on Daotan TW 7000 excellent adhesion to plastic (ABS, PC), excellent humidity- and chemical resistance Application: e.g. automotive interior plastic parts

7,5g Stapa IL Hydrolan 2154 3,5g Stapa IL Hydrolan 214 0,8g Additol XL 250 (wetting and dispersing agent) 0,2g Surfynol 104/50EG (multi purpose additive) 8,4g Butyl glycol 28,0g Daotan TW 7000/40WA 1,2g Dimethylethanol amine 10% 13,4g Viscalex HV 30 10% (thickener) 11,1g de- ionized Water 6,0g Ultralube E 500V (wax) 7,0g de- ionized Water 1,6g Isobutanol 4,3g Dimethylethanol amine 10% 7,0g de- ionized Water 100,0g 11,4g Bayhydur 3100

Pack A:

Pack B: Spraying viscosity: 300-400mPa.s/ 25s-1 Curing: 10 min flash off + 10 min 80°C

Trends

Substitute or completely eliminate NMP/NEP from PUD resins

(change in legislation, see next page)

„lower cost“ PUDs

Further improvement of humidity resistance properties

Further improvement of chemical resistance properties

Current trends in the PUD area

In Europe re- labelling of NMP (N- Methyl- pyrrolidone) was originally planned for Sept. / Oct. 2006 but had been postponed several times. Today the new NMP (N- Methyl- pyrrolidone) regulation is specifying the following: NMP: T : R36/37/38 – 61 Products with 10% NMP and higher: T : R36/37/38 – 61 Products with a NMP content from 5% to less than 10%: T : R61 This labelling has to be supplemented by a „skull“ . Products containing less than 5% NMP: NO LABELLING, but NMP content from 0,1% onwards has to be mentioned in Chapter 2 of the Safety Data Sheet.

Thank you

Our Contacts: Dr. Ulrike Kuttler Tel: +43 50 399 1302 Mobile: +43 664 38 077 82 E-mail: ulrike.kuttler@cytec.com www.cytec.com