dr. thorsten brand ecc-düsseldorf, 12.06 · pdf filedr. thorsten brand...

Can you can? We can! Polyesters for Can & Flexible

Packaging Coatings

Dr. Thorsten Brand

ECC-Düsseldorf, 12.06.2013

1. Polyesters in can coatings

2. DYNAPOL® polyesters for interior can

coating applications

3. Development push – Novelties

4. Polyesters for flexible packaging

Polyesters serve many coating end uses

Coil Coating Can Coating Flexible Packaging

Interior

coatings

HM-PES

MM-PES

Stamping enamels

(e.g. base coat

white)

HM-PES

MM-PES

Printing inks

HM-PES

Overprint varnish

(clear coat)

HM-PES

MM-PES Interior side

seam

protection

HM-PES

• In Can Coating HM-

& MM-PES is partly

used as synergistic

packs

• Main strengths

of HM-PES:

adhesion &

sterilization

resistance

• Main strengths

of MM-PES:

economy &

reactivity

The coating layers of a can are based on a wide range of high (“HM”) and medium (“MM”) molecular weight polyesters

Dynapol

LH 830-02

Coater

Only with a full understanding of the entire

value chain it is possible to have the right

solutions for the target end markets

Can

Manufacturer

End User

YOU

Brand Owner

Resin

Manufacturer

DYNAPOL®

Paint

Manufacturer

PAINT

Polyesters fulfill the technical needs for

can coatings…

Typical requirements for general coatings

• Sufficient reactivity

• Good substrate adhesion

• Blocking resistance

• Surface hardness

• Durability

• Appearance

• Sufficient flexibility for can forming process

• High sterilization resistance even vs. acidic or alkaline media

Additional requirements for can coating lacquers

…and polyesters show outstanding

characteristics in further aspects

Apart from fulfilling aforementioned technical properties

polyesters support the cured coating films to be:

• Free of taste and smell

• Hazard free

• Compliant with food contact regulation (e.g. FDA section 175.300)

• Highly durable

• Highly resistant to different media

Sub-range Properties Application

DYNAPOL® L

High molecular weight

polyesters

10.000 - 25.000 g/mol

Can coating

Coil coating

Flexible packaging

DYNAPOL® LH

Medium molecular

weight polyesters

2.000 - 7.000 g/mol

Coil coating

Can coating

DYNAPOL® LS Flexibilizer resin,

high/medium molecular

weight polyesters

Coil coating

Can coating

Flexible packaging

DYNAPOL® P, S High molecular weight

crystalline polyesters

Can coating

side seam powder

The versatile DYNAPOL® portfolio is

serving various can coating demands

Special feasibility for

interior can coatings

High and medium molecular weight

polyesters fit for interior can coating –

a comparison

0

1

2

3

4

5

Solution viscosity

Yield

Sterilization

in H2O

Sterilization in

acetic acid (3 %)

Flexibility

Glass

transition

temperature

A medium molecular weight polyester for standard performing films –

DYNAPOL® LH 318-02

• FDA 175.300 approved binder

• Synergistic effect with phenolic resins

• Good sterilization resistance to

moderately aggressive filling goods

• Recommended for 2 & 3 pc-cans

• High flexibility

• Medium film glass transition temperature

Rating Key: #5 = excellent

#1 = poor

Qualitative rating

0

1

2

3

4

5

Solution viscosity

Yield

Sterilization

in H2O

Sterilization in

acetic acid (3 %)

Flexibility

Glass

transition

temperature

A high molecular weight polyester for advanced performance films –

DYNAPOL® L 952


• High sterilization resistance

• Recommended for 2 & 3 pc

• Good balance between hardness and

flexibility

• High glass transition temperature


#1 = poor

Qualitative rating



a comparison

A high molecular weight polyester for excellent film performance –

DYNAPOL® L 912


• Very high sterilization resistance

even through acetic filling goods

• Recommended for 3 pc

• Very high glass transition temperature


#1 = poor

Qualitative rating

0

1

2

3

4

5

Solution viscosity

Yield

Sterilization

in H2O

Sterilization in

acetic acid (3 %)

Flexibility

Glass

transition

temperature



a comparison

The goal is to develop polyesters beyond

the current performance abilities –

especially in interior can coatings

Developmental aims

• Improve benchmark

characteristics

• Manufacture even higher

performing DYNAPOL® grades

Pe

rfo

rma

nce

DYNAPOL® L xxx

Benchmark polyester

e.g. DYNAPOL® L 912

Status quo

• Market feedback confirms

superior performance of dry

coating films

Key properties in order of importance – Qualitative rating

• Sterilization resistance to acetic acid (3 %)

• Sterilization resistance to H2O

• Flexibility

• Yield

• Solution viscosity

• Glass transition temperature

The performance of DYNAPOL® L 912 is

benchmark for new developments


#1 = poor

0

1

2

3

4

5Solution viscosity

Yield

Sterilization

in H2O

Sterilization in

acetic acid (3 %)

Flexibility

Glass

transition

temperature

Testing of developmental products vs.

benchmark was carried out in a fixed

reference paint formula

• Resin : Cross-linker ratio: 80 : 20

• Cross-linker: Benzoguanamine resin

• Curing time: 13 minutes

• Curing temperature: 205°C (200°C PMT)

• Viscosity DIN 4mm cup: 140 s +/- 10 s

Interior Can Coating – Guide

Formulation

p.b.w Product

60 Polyester solution (~35%)

25 Pigment

10 Cross-linker

1 Catalyst

1 Additives

3 Solvents

0

1

2

3

4

5

Solution viscosity

Yield

Sterilization

in H2O

Sterilization in

acetic acid (3 %)

Flexibility

Glass

transition

temperature

0

1

2

3

4

5

Solution viscosity

Yield

Sterilization

in H2O

Sterilization in

acetic acid (3 %)

Flexibility

Glass

transition

temperature

Yield optimized product

• More favourable solution viscosity

• Higher yield

• Good sterilization properties

L 912: purple colored

Developmental product: blue colored

Film performance optimized product

• Higher sterilization resistance to H2O

• Higher flexibility

• Higher glass transition temperature

• More favourable solution viscosity


#1 = poor L 912: purple colored

Developmental product: grey colored

The new developmental products show

significant improvement in comparison to

benchmark

Coil Coating Can Coating Flexible Packaging

Polyesters serve many coating end uses

DYNAPOL® polyesters are suitable as main-binder, co-binder or as additive in

Foil primers

Printing inks

Overprint varnishes

Foil lacquers

Heat sealing lacquers

Hot laminating adhesives

on substrate materials like aluminium, PET, PVC, PP, Paper, Cardboard, etc, …

Of course different materials can be used in one composite film.

High molecular weight polyesters are

feasible for many purposes in flexible

packaging coatings

Printing Inks

Protective top coat

Substrate: e.g. alu foil

Interlayer

Substrate: PET foil

Example - peel strength adjustment

by polyester selection

0

1

2

3

4

5

6

7

8

9

10

N /

15

mm

L 208 L 206 EP L 311-T LS 415

Peel strength at room temperature

Substrate:

Aluminium hard (20µm)

Sealing conditions:

T: 180 °C

t: 1 s

DFT: ~ 4 µm

Summary

• Polyesters offer versatile solutions for different can

coating layers / applications

• High molecular weight polyesters show superior

film performance in interior can coatings

• Most recent developmental results show excellent

progress in coating performance

• Further developmental approaches are in progress

• Due to its adaptability the substances class of

polyesters is increasingly applied in flexible packaging

coatings

6/14/2013 Novel Can Coating Solutions

Harald Jung

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