This document discusses laminating adhesives and evaluates new oligomer materials for these applications. It examines UV/EB curable laminating adhesive formulations containing oligomers, monomers, and photoinitiators. Testing of various oligomers shows that polyester and polycarbonate urethane acrylate materials like NTX12514 and PRO12546 maintain high optical clarity and bond strength after weathering, making them suitable for laminating adhesives requiring durability. Polyether urethane acrylates provide weaker bonding but better retention of properties after aging. Material selection depends on the specific performance needs of laminating adhesive applications.
2. Laminating Adhesives
Technology Types:
! Solventborne
! Waterborne
! Solventless (100% solids, 2K or
1K)
! Hotmelt
! UV/EB Curable
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Laminating adhesive: An adhesive layer to bond two substrates
together.
Processes:
! Dry Processes
• UV Laminating Process
! Wet Processes
• EB Laminating Process
! Co-extrusion Process
3. UV/EB Adhesive Laminating Process
UV Adhesive Lamination:
• High line speed
• Low VOC
EB Adhesive Lamination:
• No heat generation
• Will cure through opaque films
UV Lamp
Secondary Rewind
Unwind
Station Primary Unwind
Station
Coater
Electron Beam
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4. Markets and Applications
Food Packaging and
Consumer Goods
Medical Automobile
Photovoltaic
Electronics
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5. Performance Requirements
General Applications:
! Initial bond strength
! Ultimate bond strength
! Resistance to service environment (heat, humidity, electric)
Special Applications:
! High optical clarity
! Electrical insulation (low dielectric constant, high breakdown voltage)
! Gas permeability (moisture, oxygen, etc.)
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6. Scope of this Study
! Typical Formulation of
UV/EB Curable
Laminating Adhesives
Components Level
Oligomers 40% to 70%
Monomers 70% to 30%
Photoinitiators 1% to 3%
! New Oligomer Development
Products Type of Oligomers Viscosity at
60°C, cps
Color
CN9018 Polyether UA 20,000 <100 APHA
CN966J75 Polyester UA 4500 <100 APHA
PRO12184 Polyester UA, High
molecular weight
16,000 <100 APHA
PRO12507 Tin-free polyester UA 15,500 <100 APHA
NTX12321 Allophonate 41,000 <120 APHA
NTX11945 Bio-based UA 12,000 <120 APHA
NTX12514 Moisture-resistant
polyester UA
5600 <150 APHA
NTX12427 Polyvinyl Acetal 25,000 <150 APHA
NTX12585 Polycaprolactone UA 22,800 <120APHA
PRO12384 Polycarbonate UA 26,000 <100 APHA
PRO12546 Polycarbonate UA 22,500 <100 APHA
PRO12599 Polycarbonate UA, High
molecular weight
80,400 <100 APHA
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8. Key Performance Evaluated
! Sample Preparation
● Each oligomer was formulated using Sartomer’s standard adhesive formulation
package.
● The adhesives were laminated between DuPont (XST-6578) PET films.
● Curing condition: Under a Fusion 600 W/in D lamp at a speed of 15 fpm.
● Thickness of each adhesive sample: Tested to be approximately 9 mils.
! Application Property Test
• Initial bond strength: Instron
• Initial optical clarity: UV/Vis spectra
• Ultimate bond strength and optical clarity under different weathering conditions:
• ASTM D4329-05 cycle B QUV
• 85°C/85% relative humidity
• Freeze-thaw cycles (each cycle includes 20 hours at 85°C/85% relative
humidity and 2 hours at -40°C)
• The weathering samples were equilibrated at RT/50% relative humidity
environment for seven days before T-peel testing.
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10. Optical Clarity After 500 Hours QUV Weathering
All the materials kept optical clarity
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11. Optical Clarity After 500 Hours 85°/85%
Relative Humidity Weathering
High molecular weight polyester and polycarbonate
urethane acrylates began to lose optical clarity.
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12. Optical Clarity After 500 Hours Freeze-Thaw Cycles
Polyester urethane acrylates CN966J75, PRO12184, PRO12507 and
polycarbonate urethane acrylate NTX12599 lost optical clarity.
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14. Change in Bond Strength After 500 Hours
Weathering
! Polyester, polycaprolactone and polycarbonate urethane acrylates
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demonstrate high initial bond strength. Polyether urethane acrylate
shows weak initial bond strength.
! Most polyester, polycaprolactone urethane acrylates lost bond strength.
Polyether urethane acrylates can hold bond strength.
15. Change in Bond Strength After 2000 Hours
Weathering
! NTX12514 (Polyester UA) and PRO12546 (Polycarbonate UA) still exhibit high
bond strength after all three weathering tests.
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16. Optical Clarity After 2000 Hours QUV
! Only five products kept optical clarity after 1000 hours weathering.
! CN9018, polyether urethane acrylate lost optical clarity after
2000 hours QUV.
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17. Optical Clarity After 2000 Hours Freeze-Thaw Cycles
! All five products survived 2000 hour 85°C/85% R.H. and freeze-thaw
weathering
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18. Feature Products- Change in Bond Strength With
Aging Time
! PRO12546-Polycarbonate
urethane acrylate
! NTX12514-Polyester urethane
acrylate
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19. Conclusions
! Polyester urethane acrylates can be designed to have superior
durability even under harsh weathering conditions.
! Not all the polycarbonate urethane acrylates can deliver high
durability. Specific composition and molecular weight do matter.
! NTX12514 and PRO12546 are featured products for laminating
adhesive applications requiring:
● Strong initial bond strength
● High optical clarity
● Maintenance of high optical clarity and bond strength under different weathering
environments
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20. Thank you
For more information:
www.sartomer.com
contact@sartomer.com
(800) SARTOMER
(610) 363-4100
@SartomerGlobal on Twitter
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