New Hot Melt Formulations for Tape and Label

New Hot Melt Formulations for Tape and Label Applications Ingrid Brase & Yuhong Hu AWA Adhesives Technology Seminar Chicago March 2013

Pressure Sensitive Adhesives – Key Requirements Wet out Adhesion Allows adhesive to flow and penetrate Strong enough to bond/hold Balance of the two at a certain time scale § § § 2 Peel Strength Shear Resistance Quick Stick / Tack Heat Resistance – SAFT, Heated Shear Release Force from the liner

Pressure Sensitive Adhesives – Hot Melt: Strength § Easy to apply, no drying, no solvents, environmental friendly § Fast setting for high production speed § Short compression time § Small space needs, immediate use of product § Easy to store, 100% solids, stable § Aggressive tack, good adhesion on LSE § Cost effective 3 Hot Melt: Weakness § Relatively poor aging especially under UV § Inherently limited by high temperature (heat sensitivity) § Limited solvent-resistance

Hot Melt PSA — Raw Materials § Polymer § Tackifier Resin § Diluent § Additives 4 20 - 40% Mw > 10, 000 cohesion: inner strength flexibility, toughness 25 - 60% Mw < 5, 000 adhesive strength, stickiness determines surface energy 5 - 25% Mw <1000 optimization of flow properties, viscosity < 5% protects or modifies properties; antioxidants

Hot Melt PSA Raw Materials – Polymers Long chains molecules comprised of building blocks known as monomers. Polymer Function § § § 5 Strength Toughness Flexibility Stability Elongation Adhesion Properties dependent on: § Molecular weight distribution § Chemistry type § Co-monomer type and ratio § Morphology § Saturation

Hot Melt PSA Raw Materials – Styrenic Block Copolymers § Styrenic Block Copolymers: SIS, SBS, SEPS § Anionic polymerization, very narrow Mwt distribution § Physical crosslinking by phase separated mid-block and end-block 6 SBS SIS SEBS SEPS Thermal Stability Fair Poor Excellent Mid block Tg -85 -60 -55 Solubility Parameter 8. 35 8. 15 7. 75 7. 65

Hot Melt PSA Raw Materials – Tackifiers High glass transition temperature Low molecular weight amorphous polymers Compatible with the base polymer Tackifier Function § § § 7 Raise Tg of polymer Reduce entanglements Promote wet-out Reduce viscosity Tack Adhesion Properties dependent on: § Chemistry Type - Feed Stock Source § Viscosity § Softening Point (Ring & Ball) (~ Tg + 40 -50°c) § Molecular Weight § Acid Number § Density § Color (Gardner) § Compatibility to polymer phase

Hot Melt PSA Raw Materials – Tackifiers § Hydrocarbon base (oil & gas) § Acyclic and cyclic C 5 & C 9 § Dicyclopentadiene § Features § Used extensively in all hot melt adhesives § Good adhesion to both stiff and more flexible substrates § Low odor and color (hydrogenated HC) § Key tackifier in some regions for products used in the hygiene market § Wide formulating latitude 8

Hot Melt PSA Raw Materials – Tackifiers § Natural Sources (trees & paper industry) § Rosin Esters - derived from pine tree resins - gum rosin based or tall oil based § Terpene and derivatives - from orange peel/pine extracts § Features § Used extensively in PSA and packaging applications § Excellent compatibility with both SIS and SBS § Enhance adhesion to polar substrates § Range of softening points available leading to formulating latitude 9

Hot Melt Physical Properties Testing Bulk Properties: § Brookfield viscosity § Color § Softening point § Viscosity and color stability § Rheology § Tensile § Density 10

Hot Melt PSA — Typical Applications Labels Graphics Tapes HMPSA Hygienic Medical Automotive 11

Hot Melt PSA for Labels General Requirements § Quick stick, good wet-out on various substrates § Good die-cutting and matrix stripping § No edge lifting § Humidity resistance § Good adhesion at both ambient and cold temperatures ** § Clarity ** § Re-positionable or removable ** ** for specific applications 12

Hot Melt PSA for Labels § Application § Slot die, roll coat § Line speed, 500 – 1000 ft/min § Typical coat weight § 0. 8 to 1. 2 mil § Property and Application testing § Peel, tack, shear on SS, corrugated, LDPE, HDPE, etc. § 95% RH and 95ºF aging test § Staining test § Stripping and die-cutting § Release force test 13

Hot Melt PSA for Labels — Examples 14 Applications Properties General Purpose Paper labels Balance tack, peel, shear, permanent bond Clear bottle labels Light color, clear/no look label Packing slips Aggressive tack, migration resistance Fruit labels/ Food labels Food Contact, FDA compliance Tire labels High initial tack, good wet out on LSE Dairy labels/ Freezer labels Soft, low Tg, broad Tg, adhesion on moist surface Removable labels Low adhesion, no build up, no transfer, removable

Examples — General Purpose Labels Considerations § Adhesion / Tack § Removal / Cohesion § Die Cuttability § Staining resistance § Transparency * 15 Ingredients % range Function SIS or SBS 20 -30 Cohesion Tackifier (C 5/C 9, Rosin ester…) 45 -60 Wetting of surface, increase Tg Oil 20 -25 Surface tack, lower Tg AO 0. 5 Thermal stability

Expanding Portfolio: Low Temperature Hot Melt PSA • Gap in product line: optimized product for low temp applications • Adhesion and quik stik at low temp • Good release for auto dispensing 16

Low Temp Label Product • Utilize key raw materials to meet criteria 17

Low Temperature HMPSA for Labels: Rheology 18

Release Force Charts Original Adhesive • Release force values at 1200 in/min • Original 17. 8 grams/in • Modified 11. 3 grams/in 19 Modified Adhesive

Hot Melt PSA for Tapes General Requirements § Adhesion to hard-to-stick surfaces and various foams § Excellent holding power after aging § Good adhesion at elevated temperatures § Resistance to various environmental conditions § Met skin contact requirement ** ** for specific applications 20

Hot Melt PSA for Tapes § Application § Slot die § Line speed 50 – 300 ft/min § Typical coat weight § 2 to 5 mil § Property and end-use testing § Ultimate holding power (static shear) § Static shear at 40ºC, 50ºC and 60ºC § S. A. F. T on PET and foil § Adhesion on foam § Aging performance § Peel, tack 21

Hot Melt PSA for Tapes — Examples 22 Applications Properties High shear tape High cohesion, high S. P. high S. A. F. T. Foam tape Aggressive grab on various types of foam, high S. A. F. T. Removable tape No build up, no transfer, removable Road marking tape Aggressive tack, good aging performance Hook & loop/ diaper tape Good wet out, high cohesion, high shear at body temp, high peel adhesion Automotive tape High heat resistance, good aging performance Medical tape High MVTR, non-irritating to skin, painless removal, good grab

Examples — High Shear Tape Considerations § High shear § Cohesion § Heat resistance § Adhesion on hard-to- stick substrate § Good grab 23 Ingredients % range Function SIS or SBS 30 -40 Cohesion Tackifier (C 5/C 9, Rosin ester…) 40 -60 Wetting of surface, increase Tg End block tackifier 0 - 15 Increase shear resistance Oil 5 -20 Surface tack, lower Tg AO 0. 5 Thermal stability

Creating High SAFT/ High Cohesion HMPSA’s • High SAFT/ High Shear HMPSA’s • Balanced performance: cohesion/ adhesion • Reasonable coating viscosity 24

High SAFT/ High Shear HMPSA: Adhesion profile • 25

High SAFT/ High Shear HMPSA: Cohesion Profile Hours SHEAR 72 o. F 120 o. F 158 o. F SAFT, o. F 26

High SAFT/Shear HMPSA 27

Summary • HMPSA can be utilized for a wide variety of pressure sensitive applications • Understanding end use and process requirements is key • Skilled formulators can use tools available to meet new and emerging needs 28

Acknowledgements • • 29 Bill Chen Pete Walter Brad Mc. Leod Stephen Shepherd

THANK YOU! ANY QUESTIONS?