1. Pressure Sensitive Adhesive Tapes for Sales and Marketing Professionals
Tape University Basics May 12, 2009
Adhesives
Larry K. Post
North American Technical Services &
Strategic Account Technology Manager
Ashland, Inc.
Dublin, OH

2. Larry K. Post More than 30 years in PSA tape industry
Specializing in solution, emulsion and radiation cure PSA adhesives
B.S. and M.S. in chemistry from Wright State University
Graduate research on synthesis and polymer characterization of new polymerizable herbicide monomers
Larry K. Post
North American Technical Services & Strategic Account Technology Manager
Ashland, Inc.
Dublin, OH

3. Types of Adhesives Liquid Adhesives Solid Adhesives
Calendered (Rubber)
Hot Melt (Thermoplastic Elastomers)
Reactive (Acrylic and Silicone)
Radiation Cured
Water Based (Rubber and Acrylics)
Solvent (Acrylic, Rubber, and Silicone)

4. Common PSAs Natural Rubber Synthetic Rubber Acrylic Adhesives
Silicone Adhesives

5. Rubber Based Adhesives
Elastomer
Natural and Synthetic Rubbers (Butyl, Styrene Butadiene, Polyisoprene, Thermoplastic Elastomers)
Tackifiers
Natural (Rosin, Rosin Salts and Esters)
Synthetic Hydrocarbons(C5, C9, Polyterpenes)
Fillers
Clay, Calcium Carbonate, Talc and Silica
Plasticizing Oil
Polybutene
Naphthenic Oils
Anti-oxidants
Cross Linking Agents
Flame Retardants
Colorants
Deodorants

6. Performance Characteristics and Features
Multi-component systems requires intensive processing
Natural and synthetic components
Applied as 100% solids and from solutions
Cost effective
Good tack and adhesion to a variety of surfaces including low surface energy surfaces
Good shear strength
Duct, and some Packaging and Masking Tapes are based on Natural Rubber

7. Performance Characteristic Shortcomings
Fair Chemical, UV and Oxidation Resistance
Poor Elevated Temperature Resistance
Moderate Useful Life Time
Requires Extensive Processing (except hot melt)

8. Rubber vs. Thermoplastic Rubber Adhesives
Similarities
Differences
Natural rubber adhesives have higher operating temperatures
Natural rubber can be chemically crosslinked vs. physical crosslinks for thermoplastic rubber
Thermoplastic rubber adhesives melt
Natural rubber adhesives require intensive mixing
Tackifiers
Anti-oxidants
Fillers
Oils
Same formulating principles
Can be coated as 100% solids or from solution

9. Natural Rubber Tackification
1400
1200
1000
800
600
400
200
Natural Rubber Tackification
From Handbook of PSA Technology 3rd Edition, pg. 265, edited by Don Satas, Satas & Associates, Rhode Island © 1999.
Fig Effect of resin concentration on peel adhesion (X), tack (*) and shear resistance (0) for hydrocarbon resin in natural rubber

10. Synthetic Adhesives Acrylic Adhesives Silicone Adhesives
2-Ethyl Hexyl Acrylate, Butyl Acrylate and co-monomers
Cross Linker
Silicone Adhesives
Dimethyl and Diphenyl Dimethyl Silicones
Catalyst (Platinum or Peroxide)

11. Acrylic PSA Features Colorless-excellent clarity
Balanced shear, adhesion and tack
Low Tg
Excellent resistance to thermal and UV degradation
Excellent aging characteristics
Broad temperature performance range
Good resistance to non-polar solvents
Water resistant
Non-corrosive
Easily formulated
Biocompatible (ISO 10993)
Sterilizable (EtO & Radiation) chemistry

12. Solution Acrylics
Good balance of properties; generally higher performance than emulsion acrylics
Coater ready
Mechanically stable
Viscosity controlled by solvent & solids
Newtonian rheology
Solvent management
UL foil tape, mounting tapes, and transfer tapes

13. Packaging tape largest application for emulsion acrylics
Polymerized in water (surfactant needed)
Good properties similar to solution acrylics but typically lower adhesion, tack and shear.
Stabilize emulsion from biological attack
Some sensitive to water
Environmentally safe
Less expensive than solution acrylics
Packaging tape largest application for emulsion acrylics

14. Effect of Crosslinking and Molecular Weight on Mechanical Properties
From Advances in Pressure Sensitive Adhesive Technology, Don Satas, p. 3, © 1989, Satas & Associates, RI.

15. Silicone Adhesives’ Features
Wide temperature use range up to 500F
Biocompatible (ISO 10993)
Sterilizable (EtO and Radiation)
Resistant to moisture, UV, oxidation, chemical and biological attack
Excellent electrical insulation properties
Adheres to difficult to bond to substrate such as polyimides and fluoropolymers
Clean removability

16. Silicone Adhesives have….
Better resistance to moisture, microbes, UV, chemicals, and oxidation
Broader temperature use range
Lower adhesion and tack at room temperature, but better properties at temperature extremes
More expensive
…than acrylic and rubber based adhesives

17. Applications for Silicone PSAs
Printed Circuit Board Mask
Solder Mask
Electrical Insulating Tapes
Silicone to Silicone Bonding Applications (Splicing Tape)
Low Friction Tape
Plasma Spray Tape
Medical Applications

18. MQ Silicate Tackifier Resin
Silicone PSA Compositions
MQ Silicate Tackifier Resin
From T. Mitchell Dow Corning Presentation, February 2002

19. Properties of Adhesives
Rubber Adhesives
Acrylic & Silicone Adhesives
Chemistry
Molecular Weight
Degree of Chain Entanglement
Degree of Cross Linking Tg
Chemistry
Molecular Weight
Rubber:Resin:Filler:Oil Ratio
Degree of Cross linking Tg
Physical properties and fitness for use are governed chemistry, molecular weight, crosslink density, and additives

20. Considerations for Adhesive Selection
Environment
Temperature of Application and Use
Relative Humidity
Exposure to Sunlight, Water, Chemicals
Application
Machine or Hand Applied
Speed of unwind or liner removal
Pressure of application
Time for bond formation
Functionality
Surface (Chemistry, Texture and Cleanliness)
Barrier Properties
Removable residue free, repositionable or permanent
Leachable Materials
FDA compliant (skin and food)
Regulatory compliant
Material and Performance specifications
Life Time
Cost
Chemistry and Process determine adhesive properties which combined drive COST!

21. Performance Comparison
TACK and PEEL: Rubber>Acrylic>Silicone
COHESIVE STRENGTH at
ELEVATED TEMPERATURE: Silicone>Acrylic>Rubber
STABILITY: Silicone>Acrylic>Rubber
TEMPERATURE RANGE: Silicone>Acrylic>Rubber
COST: Silicone>Acrylic>Rubber
Convertibility Silicone>Acrylic>Rubber

22. How Things “Stack-Up”
* High to low surface energy silicones, poor to low surface energy ethylenes
J Johnston - Personal communication

23. How do you know which adhesive to use?
Factors to Consider
Surfaces
Application
Functional Properties
Service Temperature
Thermal Resistance
Chemical Resistance
Barrier Properties
Durability
Construction
Cost
The selection of the type of adhesive is determined by understanding the functional properties required, application technique and cost.