High Performance Copolymer Dispersions for Flexible Packaging

October 17, 2005

Christopher Guy & Norman Seung

Agenda

• Ethylene Acrylic Acid Dispersion History• Overview of Ethylene Acrylic Acid

Chemistry Used• Versatility of Markets and Applications• Limitations of Traditional EAA Dispersions• New and Future Developments with EAA

EAA Dispersion History

• EAA Dispersions have been commercially available since the early 80’s

• Features of Traditional EAA dispersions:– High Acrylic Acid Content (20%)– 100% Waterbased– Surfactant-Free– Runs on Conventional Coating Equipment– FDA and BGVV Approvals

O

OC+

H

HC

H

H

C

H

H

C-

Ethylene Acrylic Acid

H

H

C-

H

H

C-

H

H

C-

H

H

C-

H

C-

H

H

C-

H

H

C-

H

H

C-

H

H

C-

O OHC

H

HC

H

CH

--

Ethylene Acrylic Acid Chemistry

Polyethylene lamellaecontaining no branching

Polyethylene lamellaecontaining branching

Branching and comonomers interfere with the folding process.

Branching in PE decreases the crystallinity.

Effect of Branching on Crystallinity

Typical Properties of Ethylene and Acrylic Acid

Ethylene• Water Resistance• Flexibility• Barrier Properties• Chemical Resistance

Acrylic Acid• Adhesion• Low Heat-Seal

Temperature• Toughness• Optics

Application Requirements

Parameters affecting adhesion• Wettability• Chemical attraction• Flow characteristics of polymer

– Viscosity of aqueous dispersion– Melt-flow of deposited polymer

Surface Wetting

30354045505560

0 20 40 60 80 100

Temperature (deg. C)

Dyn

e / c

m

10% AA20% AA MI 300w/ defoamer20% AA MI 1300Low Visc.w/IPA

Increasing Coating Temperature Lowers Surface Tension

Chemical Attraction

Hydrogen Bonding adds: - melt strength- tensile strength- hot tack

Carboxyl Group

C0

0 HC0

0H

--

+ C0

0 H+

-0C0H

-

+

+

Adhesion to polar substrates

Flow Characteristics

• Shearing stress of the coating can impact the viscosityof EAA dispersions.

Application Specifics

• Applied via low viscosity coating equipment (gravure, flexo, air knife, meyer rod)

• Dry the dispersion to remove water and fuse polymer• Cool coating to 140°F (60°C) to prevent blocking• Aging is not required - can be extrusion coated

immediately • Typical priming coating weights

– Non-porous films and foil - 0.5 to 1.0 g/m²– Paper - 0.8 to 1.2 g/m²

• Typical lamination coating weight– Least porous substrate - 1.6 to 2.4 g/m²

Applicator:gravure

flexomeyer rod

Substrate

Aqueous Dispersion of EAA (10-25% non-volatile)

Drying

(60 – 130°C)

Typical Coating of the Substrate0.5 – 2 g/m2

Application Specifics

Excellent Good Poor(>3lbs/in) (1-3 lbs/in) (<0.5 lbs/in)

Aluminum PE PPSteel EVA PETGlass Nylon PVCPaper CPE EVOHIonomers Copper PCEMAA

180° T-peel test of composite samples

EAA Adhesion Recommendations

Typical Primers Used

• Polyurethane (one and two parts)• Polyester and polyester urethane• Acrylics (various different types)• Polyvinylidene chloride• Polyethylene imine• Vinyl (copolymer and blends)

Agenda

• Ethylene Acrylic Acid Dispersion History• Overview of Ethylene Acrylic Acid

Chemistry Used• Versatility of Markets and Applications• Limitations of Traditional EAA Dispersions• New and Future Developments with EAA

Aqueous inks Metallized Paper Paper saturation

Textile warp sizing Coatings Coated filler

Lamination Flexible packaging Bottle coatings

Paint Fabric coatings Nonwoven binders

Primer / Tie Coat Glass fiber sizing Heat Seal Coatings

Overprint varnishes Can & coil coatings Medical

Possibilities…

Medical

• Medical Device Packaging– Excellent adhesion to Tyvek®– Forms a clear, flexible and breathable film– Enables gas-sterilization– FDA and BGVV Compliant

• Medical Garments– Melt flow reaches 1,300 g/10 min (190°C)– Binder for multiple layer porous sheets

Heat Seal Coatings

• Improving line speeds with– Low heat seal temperature, sealing 20-30°C

lower than polyethylene– Excellent hot tack

• Low viscosity coating allows application on traditional coating equipment

• Pattern Applied if Desired• Thinner films than extrusion coatings• FDA and BGVV compliant

Metallized Paper

• Pre-treatment coating used to prepare base paper to accept metallization

• Improves vaporized aluminum adhesion to paper

• Post-metallizing coating to protect aluminum surface of paper and reduce oxidation

Paper and Film Lamination

• Used as a tie layer• Adhesion to

– Foil, Paper, LDPE, Nylon • Water, grease and oil resistant• Effective at low coating weights• Applied via conventional coating

equipment

Agenda

• Ethylene Acrylic Acid Dispersion History• Overview of Ethylene Acrylic Acid

Chemistry Used• Versatility of Markets and Applications• Limitations of Traditional EAA Dispersions• New and Future Developments with EAA

New Developments

• High Performance Characteristics– Enabling Adhesion to More Substrates – Increasing Bond Strength– Reducing Heat Seal Temperature– Improving Hot Tack– FDA and BGVV Food Compliance

Enabling Adhesion to More Substrates

• Coating adhesion to:– PP – PET– PVC

• New Developments with Michem®Prime show improved adhesion to a wide range of substrates and can eliminate need for a primer.

Bond Strength to LDPE

0

50

100

150

200

250

300

350

400

450

100 110 120 130 140 150 160

Temperature (°C)

Bon

d St

reng

th to

LD

PE (g

MP 48525RMP2960MP498345NMP4983R

Improving Bond Strength

Future Modifications

• Capabilities include modification to:– Water Sensitivity– Heat Seal Temperature– Hot Tack– Foam Control– Rheology Control

Conclusions• Developments in EAA Dispersion

Chemistry have enabled:– Faster line speeds in flexible packaging with

lower heat seal temperatures– Increased Versatility of Substrate Use with

Improved Adhesion to Broad Range of Substrates

– Improved Bond Strength– Broadened Application Ease of Use– Maintained FDA and BGVV Compliance

Contact Information:Christopher Guy9080 Shell RoadCincinnati, Ohio 45236513.793.7766 (p)513.793.2504 (f)chrisguy@michelmaninc.com

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