New Developments – Environment Friendly Adhesive Systems

Shilip Kumar – Business Manager Rohm and Haas (India) Pvt. Ltd.

August, 2008

Contents

• Drivers for Innovation in Adhesives• Laminating Adhesives – An overview• New Developments :

– Solvent-Free Adhesives• Fast Cure adhesives • Retort / Boil in Bag adhesives • ELM adhesives

– Water Based Dry Lamination adhesives

Drivers for Innovations in Adhesives

• Key Drivers – Total Cost reduction– Shorter order to ship cycle times– Stricter regulations and increasing consumer awareness of food

safety– Packaging with enhanced features– Environmental concerns

• Innovations to address these needs– New generation Solvent-free adhesives:

• Fast Cure• High Performance – Retort Grade

– Water-based adhesives

Solvent-based Dry Lamination

• Solvents to be dried • Typically 2 component polyurethane (PU) adhesives

+ Relatively easy to run + Versatile: General Purpose to High Performance- Residual solvent odour in laminate- Safety & Health risk- Environmental pollution- Risk of carcinogenic aromatic amine- Slower speeds versus solvent-free- Most expensive

Solvent-free Lamination

• No Solvents used• 1 or 2 component Polyurethane (PU) adhesives

+ Most cost effective+ High speeds+ No residual odour/solvent- Needs skilled operators and good equipment- Handling of isocyanates, health risk- Risk of carcinogenic aromatic amines- Difficult to run rigid & polar substrates (e.g. PET/Foil)

Water-based Dry Lamination

• Water-based emulsion• 1 or 2 component acrylic based adhesives

+ Cost effective+ No residual odour+ No risk of carcinogenic aromatic amines+ Can be used on existing Dry Laminators at similar speeds to SB+ Ease of use+ Immediate slitting and processing+ Environmentally safe- Drying capacity of machines- Ink compatibility- Needs Operator training

Dry

Pro

duct

s

Generally 2 layer laminates

Adhesives – Applications

High Performance

Mainly SB, New SL

Medium Performance-SB, SL,

WB (lower end)

General Performance - SB, WB, SL

Liqu

ids

Ret

ort

Typically 3 layer laminates 4 layer complexlaminates

Laminating Adhesives : How They Stack Up

Good

Fair

Low

Economics Safety, Odor Risk Cure Time*

* - Slitting, heat sealing

Processing

Low

Low

High

High

Low Easy

Fair Easy

Fair

Key Regulations : Adhesives in Food Packaging

21 CFR 175.105 To cover laminates subjected to room temp applications (49°C and below).

21 CFR 177.1390Laminate structures for use at temp of >121°C (retortable laminates)

21 CFR 177.1395Laminate structures for use at temp between 49°-121°C as boilable, hot-fill.

• 90/128 EEC : PAA limit : 10 ppb • BgVV : PAA limit : 2 ppb • FDA : Compositional regulation/need for functional barrier

Solvent-Free Adhesives – Concerns

• Low green bond.• Minimum 24hrs cure time for slitting.• Suitable only for General performance segment and

some Medium performance jobs.• Food Legislation - Carcinogenic Primary Aromatic

Amine issues.

Solvent-Free New Developments

• Fast cure • Retort / Boil in Bag • Extremely Low Monomer (ELM)

New Fast Cure Solvent-Free adhesives• Unique Fast Cure Technology

– RT Applied & Cured– Similar pot life as current products– 200 gms/25mm bond seen in 2 hrs– Second pass & Slitting possible in 4 hours – Ready to fill in 3 days (including liquids)– Good Metal adhesion – Met.PET & Foil– Lower Work in Process (WIP) costs – Hot fill FDA clearance (177.1395) – 3 days with Mor-FreeTMC-411 & 5 days

with Mor-FreeTM C-132-1Products commercialized :• Morfree L75-164 + C-411 (100 : 40 pbw)• Morfree L75-164 + C-132-1 (100 : 63 pbw)

To know more about our Mor-Free L75-164 Fast Cure Technology…http://go.rohmhaas.com/morfree

Pot Life of MF 75-164/C-411 at 100:40 Mix RatioPot Life For Mor-Free L 75-164/C-411

0.00

2000.00

4000.00

6000.00

8000.00

10000.00

12000.00

14000.00

16000.00

0:00:00 0:14:24 0:28:48 0:43:12 0:57:36 1:12:00 1:26:24

Time, Hours:minutes:seconds

Visc

osity

, cp 25°C

38°C43°C49°C

Pot life at 38° C 30mins

Pot Life of MF 75-164/C-132-1 at 100:63 Mix RatioPot Life For Mor-Free L 75-164/C-132-1

0.00

2000.00

4000.00

6000.00

8000.00

10000.00

12000.00

14000.00

0:00:00 0:14:24 0:28:48 0:43:12 0:57:36 1:12:00 1:26:24

Time, Hours:minutes:seconds

Visc

osity

, cp 25°C

38°C43°C49°C

Pot life at 38° C 43mins

Comparative Bond Strength Development

Bond Strength Development in PET/PE

0100200300400500600700800900

MF403A/C-411 MFL75-164/C-411 MFL75-164/C-132-1

Avg

.Loa

d in

gm

s/25

mm

4hrs 8hrs 24hrs 48hrs 26days

Bonds develop rapidly in 8hrs

Conclusion - New Fast Cure / Hot Fill

• Cure response is fast, pot life is similar to more slowly curing products• Fast bond development for further processing (500 gms/25mm in 8

hours) • Good metal adhesion depending on coreactant choice (Mor-FreeTM C-

411)• A solvent free product that can be used for hot fill applications and has

FDA 177.1395.• Room temperature application and cure.

Solvent-Free for Retort Laminates

• Mor-FreeTM 225 / C-33 is a new retort grade SL adhesive system• Meets FDA 177.1390 and 177.1395• Better Economics due to lower coat weights as compared to SB

adhesives.• Is RT applied and can be RT cured, but hot room is generally

recommended to speed up cure. • Is more robust on all clear barrier structures.• Not recommended for foil containing structures with aggressive fills

Physical Properties – Mor-FreeTM 225/C-33

Mix Ratio 100 : 100 pbw

Viscosity 3500 / 2400 cps

Sp. Gravity in gms/cc 1.176 / 1.170

Application temp 43 – 54 °C

Pot life 20mins at 54 °C

Coat weight 2.0 – 2.4 gsm

Bond Strength study

0

500

1000

1500

2000

2500

Pre-RetortBond

Post RetortBonds

Bond

s - P

eak

Load

(GLI

)

PetSiOX/Nylon/440CPPDupontLBT/SiOxNylon/440CPPPETAlOx/Nylon/440CPP

Solvent-Free ELM

Sources of Primary Aromatic Amines– Adhesives– Inks– Laminate Construction– Additive composition in Films– Curing conditions of laminate– Storage conditions of laminate– Age of structure

Amines may be formed as follows:

Isocyanates react with water

R - NCO + H20intermediate stage, carbon dioxide splits off

R - NH2

corresponding amine is formed

Amines may be formed as follows:

Polyurethanes can hydrolyse(especially under sterilization conditions)

R`- O - CO - NH - R + H2Ointermediate stage, carbon dioxide splits off

R`- OH + R - NH2

1 component

2 comp MDI based

Hybriddifferent NCO´s

ELMExtremely Low Monomer

Aliphatic0 %

0.1 %

> 10 %

Aro

mat

ic N

CO

leve

l

Historical Developments in Solvent-Free Technology

Solvent Free ELM Adhesives - Specific Advantages

Easy to use and process• Ambient cure, no post curing • No preheating in hot rooms• Extremely easy to use, less waste,

clean-up and down-time• To be applied at very high

application speeds without misting at low application temperatures

• Very stable pan life, no moisture reactivity in the pan, no waste

• Excellent wettability of “difficult”substrates

Total Safety• Dramatically reduces the risk of

Primary Aromatic Amine formation• Reduces the risk of anti seal effect• No hazardous substances, no

transport or storage restrictions ELM ProductsMor-FreeTM 415+CR88-551

Mor-FreeTM ELM415+CR88-554

Mor-FreeTM ELM415+CR87-550

Superior Properties• Universal product tailored to

application needs with choice of co-reactant

• Good adhesion to films, metallizedfilms and aluminum foil

• Superior chemical and heat resistance with hot fill

• Extremely good sealability

0,00

1,002,00

3,004,00

5,00

6,007,00

8,009,00

10,00

1 3 7 14 18 22 29Days

µg/1

00 m

l/4 d

m²

Aliphatic Polyurethane

ELM 415 A + CR 88-554

Hybrid Polyurethane

NCO/OH Polyurethane

Mor-Free ELM Solvent-free AdhesivesFood Contact & Migrations

Old Limit 2002-72/EC20 ppb

Decay example of Primary Aromatic Amines

in a OPA printed – PE Laminate

New limit 01/07/200810 ppb

TR

EN

D

Acrylic WBDL For Flexible Packaging

Water Based Acrylic Adhesive Chemistry –Very Different from SB/SL PU Systems

• An emulsion polymer made by free radical polymerisation of acrylic monomers on water.

• High MW polymer particles finely suspended in water.• Appearance : Opaque white• Particle Size : 0.05 – 1.0 microns• Molecular Weight : 500,000 – 1,000,000 is typical• Very flexible – Laminate bond strength is related to the

deformation energy required to separate the laminate.

WB Adhesives - Benefits

• User Friendly – Easy Mixing / No Viscosity Adjustment• Cost effective• No Adhesive wastage • Better Optics• No VOC or DG Issues• Safer, Greater Regulatory Compliance• Faster Processing – No WIP• Shorter Time to Market• Performance Equivalent to Medium Performance PU

Systems

Water Based Acrylic vs Solvent Based UrethaneWater Based Acrylic• Very High Molecular Weight• Low Viscosity (Particles)• High Application Solids

Solvent Based Urethane• Low Molecular Weight• Viscosity increases dramatically

with increasing molecular weight (Chains)

• Low Application Solids

Energypropagates

crack

Energydeformsadhesive

High adhesion/Moderate cohesion

Moderate adhesion/High cohesion

vs.

Polyurethane :

Acrylic :

Robond - How it works

Shear vs. Laminate Bond Strength

0

200

400

600

800

Green BondStrength

Cured BondStrength

Green ShearStrength

Cured ShearStrengthB

ond

Stre

ngth

(gra

ms

/ 25m

m) S

hear

Str

engt

h (k

N/m

2) Robond 1K GP Adhesive

Solvent Based MP Urethane

Robond 2K MP Adhesive

32

Factors to Consider

1. Cylinder2. Pump3. Dryer – Air velocity, Volume of air, Exhaust4. Nip temperature and pressure5. Smoothing Bar6. Ink compatibility wet-out

33

Cylinder – Different Cell Geometries

Pyramid Quad Channel Quad (QCH)

Smoothing Bar

Smoothing Bar

Pump selection

• Critical to minimize foaming• Select pumps with minimum shear• Do not use ink pumps, centrifugal or

gear pumps• Recommendation:

– peristaltic or – diaphragm

The RobondTM L Family

Robond L-90DRobond L-90D

General PurposeGeneral Purpose

Robond L-208 / CR-3ARobond L-208 / CR-3A

Medium PerformanceMedium Performance

Robond LAcrylic Dry Bond

Laminating Adhesives

* Robond L-168A – New Development

Concerns with WBInk wettability

• Universal Ink wet-out is an issue• Wet-out problem can be resolved using an “Inline corona treater”.• Corona Treater cleans the surface of the printed film of waxes, low

molecular weight compounds,..

• New Product to address this concern – Robond L-168A• Robond L-168A has good wettability shown promising results on a

wide variety of Ink systems.

Robond L-168A overcomes ink and substrate wetting issues

With General WB With Robond L-168APoor wetting 100% wetting

Robond L-168A overcomes ink and substrate wetting issues

With General WB With Robond L-168APoor wetting 100% wetting

Conclusion

Environment Friendly WB adhesives a viable option forGP & lower end MP applications.

Newly developed product will address Ink wet-out relatedissues.

Rohm and Haas Company -Leading supplier of adhesives and coatings for the flexible packaging industry

A comprehensive product portfolio for all bonding needs

• Adhesives for paper,film and foil lamination

- General purpose through high performance.

- Water-based, solvent-based, solvent-free energy curable.

• Heat-and cold-seal coatings- Solvent-based, water-based, barrier,

dispersions.• Primers • Extrudable Tie Layer

resins

Thank you for the kind attention.