1. Heat Seal Characteristics of
Cyclic Olefin Copolymer /
Polyethylene Blends
Randy D. Jester
TAPPI 2002 PLACE Conference
Boston, Massachusetts
1

2. Topas® COC Manufacturing Plant
• Oberhausen, Germany
• Start-up October 2000
• COC Capacity: 66 MM lbs.
• Backward integrated in Norbornene
• Cost efficient continuous process using
metallocene technology
Largest COC and Norbornene Plant in the World

3. What is COC?
catalyst
+ CH2 CH2 CH2 CH2
n m
Feedstocks Catalyst : Metallocenes
Norbornene High activity, low residues
Ethylene Narrow MW distribution
Microstructure control
COC properties can be tailored by adjusting the
Norbornene content

4. Abstract
• Cyclic Olefin Copolymers (COC) use is
growing in flexible packaging films
• Attributes include easy processing, stiffness,
heat resistance, moisture barrier and clarity
• Can be used to modify the heat sealing
characteristics of polyethylenes:
– improvements in seal strength
– improvement of hot-tack strength
– high temperature seal through capability with
high Tg grades.

5. Experimental
• Materials: MI Density Tg°C
– Dow 2045 LLDPE 4 0.920 -127
– Equistar NA 952 LDPE 2 0.918 -127
– Equistar NA 204 LDPE 3 0.931 -127
– Borealis 7230 LDPE 4.5 0.923 -127
– Exxon Mobil 3125 Plastomer 1.2 0.91 -121
– Dow 1140 Plastomer 1.2 0.902 -121
– Ticona 8007 COC 1.8 1.02 80 (low)
– Ticona 5013 COC < 1.0 1.02 136 (high)
• Extrusion:
– 25 mm Killion (DS), DSB I barrier type screw, 30: 1 L/D,
Maddock Mixing head
• T range: 160 - 260°C, Cast rolls: 35°C,film: 51
microns

6. Experimental (cont.)
• Testing Equipment:
– Tensiles MTS 8016 Tensile testing machine,, 23°C, 50%
r.h. (ASTM D 882)
– Microscopy Optical (phase contrast)
– DMA TA Instruments Dynamic Mechanical Analyzer
(DMA), model 2980, tension mode on MD film, 3°C/min.
temperature sweeps, at 10HZ
– Heat Seal Davinor Inc., J&B Hot Tack Tester
• Seal Strength Test - Seal Pressure = 0.3034 N/mm (44psi), Seal
Time = 1 sec., Cool Time = 30 sec., Peel speed = 200 mm/sec,
sample size = 25.4 mm (1 inch ) wide.
• Hot-Tack Test - Seal Pressure = 0.3034 N/mm (44psi), Seal Time =
1 sec., Cool Time = 0.1 sec., Peel speed = 200 mm/sec, sample
size = 25.4 mm (1 inch ) wide.
• Seal Initiation Temperature - defined as seal temperature where a
8.8 Newton seal strength is achieved.

7. COC allows downgauging of films
1.E+05 1.00
Blend Modulus
Thickness @ Constant Initial Stiffness(mils)
Film Stiffness @Constant
Thickness
Blend Layer Thickness (mils)
Blend Modulus (psi)
1.E+04
Initial Construction: Plastomer - 0.6 mils
Dowlex 2032 - 0.8 mils
Plastomer - 0.6 mils
1.E+03 0.10
0.0% 2.5% 5.0% 7.5% 10.0% 12.5% 15.0% 17.5% 20.0%
Reference 2 Wt % 80C Tg COC
COC blends offer potential cost savings

8. Improved Ultimate Seal Strength with 80ºC Tg COC
blended with LLDPE
40
0 % COC
35 15 % COC
Seal Strength (Newtons)
25 % COC
30
25
20
15
Dwell Time = 250 ms
10 Seal Pressure = 63 psi
5 cast film
0
70 80 90 100 110 120 130 140 150 160 170
Reference 2 Sealing Temperature (°C)
COC blends produce a wider sealing window

9. Effect of Blending 80ºC Tg COC with LLDPE
on Hot Tack Force
5
0 % COC
15 % COC
Hot Tack Force (Newtons)
4 25 % COC
3
2
Dwell Time = 250 ms
1 Seal Pressure = 63 psi
0
70 80 90 100 110 120 130 140 150 160 170
Reference 2 Sealing Temperature (°C)
COC blends produce a wider sealing window

10. Effect of COC Addition on Seal Strength
60
LDPE, Den.=0.923, MI = 4.5
LLDPE Den.=0.920, MI=4
Plastomer Den.=0.91, MI=3
Seal Strength @ 120C (Newtons)
50
40
30
20
10
0
0 20 40 60 80 100 0 20 40 60 80 100 0 10 15 20 40 60 80 100
LDPE LLDPE Plastomer
% 80ºC Tg COC in Blend

11. Effect of COC Addition on Hot-Tack
16
LDPE, Den.=0.923, MI = 4.5
LLDPE Den.=0.920, MI=4
Plastomer Den.=0.91, MI=3
14
Hot Tack Strength @ 120 C
o
12
10
8
6
4
2
0
0 20 40 60 80 100 0 20 40 60 80 100 0 10 15 20 40 60 80 100
LDPE LLDPE Plastomer
% 80ºC Tg COC in Blend

12. Effect of 80º C Tg COC Addition on SIT
140
LDPE, Den.=0.923, MI = 4.5
LLDPE Den.=0.920, MI=4
Plastomer Den.=0.91, MI=3
130
Seal Initiation Temperature (SIT) = Temp. where 8.8 Newton seal strength
achieved
Seal initiation Temperature (ºC)
120
110
100
90
Seal < 8.8 N
80
0 20 40 60 80 100 0 20 40 60 80 100 0 10 15 20 40 60 80 100
LDPE LLDPE Plastomer
% COC

13. Seal Strength at 120ºC of LDPE vs. LLDPE
35
30
LLDPE to COC - no distortion of COC, LLDPE tore during pull
Ultimate Seal Strength (Newtons)
LDPE to COC - no distortion of COC, LDPE peeled off cleanly
25
20
15
10
5
0
LLDPE 60% LLDPE/ LDPE 60% LDPE/ LLDPE to LDPE to
40% COC 40% COC COC COC
60% LLDPE/40% 60% LDPE /
COC @ 2X seal 40%COC @ 2X
pressure seal pressure

14. Phase Contrast Optical Microscopy:
80% 12 MI LDPE + 20% 80°C Tg COC,
51 µm cross section, 625X
160C
180C
200C
Reference 3

15. Seal Through Test Results
200
180
Seal BarTemperature (Celsius)
160
140
120
100
80 Initial Seal Bar
Sticking
60 Seal Bar
contamination
40
LLDPE - density=0.920, MI=4
20
Plastomer, density=0.902, MI=1.2
0
90% 130 Tg 5% 130 Tg 10% 130 Tg 15% 130 Tg 20% 130 Tg 30% 130 Tg 40% 130 Tg
COC / 10% COC / 95% COC / 90% COC / 85% COC / 80% COC / 70% COC / 60%
Plastomer LLDPE LLDPE LLDPE LLDPE LLDPE LLDPE
High Tg COC as an outer layer blend
component can provide seal through capability

16. Conclusions
• COC/polyethylene blends can exhibit both improved
modulus and heat seal performance
• COC is more compatible with LLDPE and Plastomers
than LDPE
• COC level and matrix polymer affect heat seal
performance
– 80º Tg COC generally improves hot tack strength at all
blend levels for the polyethylene systems studied.
– 80º Tg COC reduced the seal strength of LDPE at
concentrations of 20% and up while maintaining or
improving the seal strength of LLDPE and Plastomer
• 130º Tg COC blended at levels above 20% can provide
“seal through” capability to polyethylenes

17. Acknowledgements
I would like to thank the following people for their
contributions to this paper:
• Dr. Rong Chen
• Dr. Angel Romo-Uribe
• David Constant
• Robert Roschen
• Rick Vliet
• Betsy Kelly
• Kathy Fitzgibbon
• Betty Fernekess
1

18. References
1. ASTM, Designation: F 1921-98, Standard Test Methods for Hot Seal Strength
(Hot Tack) of Thermoplastic Polymers and Blends Comprising the Sealing
Surfaces of Flexible Webs, ASTM Standards 1999
2. R.R. Lamonte, “Stiffer, Thinner, Packaging Films with Improved Sealing
Using Cyclic Olefin Copolymers”, Flexpac Conference, Amsterdam, Holland,
November 2000
3. D.R. Constant, “Cyclic-Olefinic Copolymers as Non-Migrating Polymeric Slip
Additives in LDPE Cast Films”, ANTEC 2002 Conference, San Franscico, CA

19. Backup Slides

20. Regulatory Status
FDA Food Contact Notification (FCN No. 75) became effective August 22,
2000
Norbornene is listed by the EU as an approved monomer for use in polymers
in contact with food.
USP Class VI
FDA Drug Master File, DMF# 12132 and Device Master File, MAF # 1043
established
COC meets all major regulatory requirements