Aqueous polyolefin dispersion for packaging boards and papers...• Heat sealability • Elasticity/flexibility • Adhesion to polyolefins + • Coat complex geometry • Coat in

Aqueous Polyolefin Dispersion for P k i B d d PPackaging Boards and Papers

Jouko Vyorykka1, Karl Zuercher1, David Malotky2

1Dow Europe GmbHDow Europe GmbH2The Dow Chemical Company

PaperCon 2011 Page 1059

Outline

• Polyolefin dispersions processing and fundamental propertiesproperties

• Materials and ResultsAdhesion priming- Adhesion priming

- Barrier improvement- Performance balancePerformance balance

• Summary and Conclusions


Introduction


Processing Plastic PelletsProcessing Plastic Pellets

Printing/Coating Spray coating

Plastic PelletsPhoto

F th d F

Photo

Dipping Frothed FoamsDipping


Processing Waterborne Polyolefin Dispersionsg y p

Printing/Coating Spray coating

Photo

F th d F

Photo

Dipping Frothed FoamsDipping


Aqueous Polyolefin Dispersions (POD)

Positive performance characteristics of polyolefins:• Heat sealability• Heat sealability

• Low temperature flexibility• Water & chemical resistance

+Application benefits of water-borne systems:

• Adhesion to polar substrates• Acceptance of inorganic fillers• Acceptance of inorganic fillers

• Low viscosity application


How are PODs different from other dispersions?

• Dispersion of polymers which are not self-dispersingDispersion of polymers which are not self-dispersing• High molecular weight polymers• Thermoplastic and elastomer formulationsp• Low viscosity• High solids• Solvent-free solution


Aqueous POD benefitsAqueous POD benefits

Waterborne Application vs Extrusion Properties of PODsWaterborne Application vs. Extrusion• Thinner coatings • Use existing waterborne application

i t

Properties of PODs• Water resistance• Oil & grease resistance

equipment • Higher line speeds• Penetrate porous/fibrous webs

• Heat sealability• Elasticity/flexibility • Adhesion to polyolefins

+p

• Coat complex geometry• Coat in pattern

p y• Adhesion to polar

substrates


Continuous Mechanical Dispersion Process

Optional SurfactantDilution WaterInitial Water

Continuous High Shear Mixer

Liquid or Molten Polymers

HIPE System:- Water continuous phase- Rhombohedral particles

- High viscosity

Spherical Particles< 75% Solids

High viscosity- 90+% Solids

Ref : U.S. Patents: 5,539,021; 5,959,027; 5,688,842; 5,959,027; 6,087,440HIPE = High Internal Phase Emulsion

®TM Trademark of The Dow Chemical Company (“Dow”) or affiliated company of Dow


POD Characteristics

Polyolefin

Water

Stabilizing Agent

• Avg particle size: ~ 1 µmAvg. particle size: ~ 1 µm• Solids content (wt%): 40 to 55% • pH: 8.0-10.5

Semi-crystalline polymers

• Viscosity (Brookfield @ 25°C): < 500 cps


Properties of PODs

• Water resistanceOil & i t• Oil & grease resistance

• Heat sealability

El ti it /fl ibilit• Elasticity/flexibility

• Adhesion to polyolefins Olefin backbone

• Adhesion to polar substrates


Materials and Results


Product description

P d t T t P l F tiPolymer

ltiPolymer

lProduct designation

Target performance

Polymer composition

Functional groups

melting point [˚C]

glass transition point [˚C]

POD Primer Primer Ethylene-Copolymer Medium 63 -53

POD Eth lPOD Standard Standard Ethylene-

Copolymer Low 63 -53

Barrier Ethylene-POD BI Barrier Improvement

EthyleneCopolymer Low 63 -53

POD BR Blocking Propylene- Medium 80 26POD BR Reduction copolymer Medium 80 -26

®TM Trademark of The Dow Chemical Company (“Dow”) or affiliated company of Dow


Adhesion priming

9 0EPE - 280 C EPE - 300C

6.0

7.0

8.0

9.0

ng [0

-10]

2.0

3.0

4.0

5.0

Adh

esio

n ra

tin

0.0

1.0

2.5 2.5 0.8 0.8 Ref Ref

C C C

A

Coat weight [g/m2]

P t t t

• POD priming improves adhesion already at 0.8 g/m2

none Corona none Corona none CoronaPre-treatment

• Enables higher extrusion coating line speeds


Water Vapor Barrier Improvement

WVTR (90% RH, 38C)

8006 / 2 10 / 2

500

600700

m2

*24h

]

6 g/m2 10 g/m2

200

300400

WVT

R [g

/m

0100

50 60 70 80 90 100 110

Normalized polar content

• Reduction of polar content improves significantly t b i


water vapor barrier


Water barrier improvement

H2O absorption (Cobb 2 min)

3.00

2.00

2.50

ion

[g/m

2] 6 g/m2 10 g/m2

0 50

1.00

1.50

ater

abs

orpt

0.00

0.50

50 60 70 80 90 100 110

N li d l t t

Wa


• Reduction of polar content improves significantly t b iwater barrier


Improved dispersions

Test resultsPOD BI

Barier improved dispersion

POD BRBlocking reduced

dispersionp p

Barrier test results

WVTR (90%,RH 38C) [g/m2/24h] 54 185

WVTR (50%RH, 23C) [g/m2/24h] 13 9.5Cobb 2 min [g/m2] [g/m2/24h] 0.1 0.6Grease resistance (Kit test) folded sample 12 12

Blocking test results

Blocking rating / fiber tear % (45˚C, 1500 psi) 3 / 0% 3 / 0%Blocking rating / fiber tear % (60˚C 1500 psi) 5 / 83% 4 / 0%Blocking rating / fiber tear % (60 C, 1500 psi) 5 / 83% 4 / 0%

Heat seal performance

Heat seal initiation temperature (˚C) <70 <100


Summary and Conclusions


Summary

• Polyolefin dispersion have potential to:- Reduce steps to build existing structures and create new

structures.- Coating with online paper or paperboard machineCoating with online paper or paperboard machine

• Thinner coatings at higher line speeds• Use existing coating techniques

- Enable sustainable solutions• Fluorochemical free• E it l VOC• Emits low VOCs• Lower material use


Conclusions

• Benefits demonstrated in:- Adhesion primer between paper and extruded polyolefinAdhesion primer between paper and extruded polyolefin- Dispersions with improved water and water vapor resistance- Oil and grease barrier with balance of water vapor barrier

→ Polyolefin Dispersions have broad application potential

- Low in-reel blocking with 100% polymer and heat sealing can be achieved

→ Enables on-line coating in paper or board machine


Thank you!


Documents

Aqueous polyolefin dispersion for packaging boards and papers...• Heat sealability • Elasticity/flexibility • Adhesion to polyolefins + • Coat complex geometry • Coat in