The Dynamic Tensile Test
Rich St. Coeur, Manager of New Technology Platform Development; Jennifer Feys, R&D Product Development Specialist
Intertape Polymer Group, Marysville, MI

This paper will examine the use of a new method to measure creep resistance of pressure-sensitive adhesives. To prove validity, the new method is directly compared to the face-to-face shear test. In this comparison, the new method delivers test results in less time with less variability and higher reproducibility than the face-to-face test. An analysis of the data presented in the report yields an R² adjusted correlation of 77.2% between the two tests for all tape samples values measured and 91.0% for those samples with face-to-face shear values greater than 100 minutes.

Evaluating the Physical Properties of PSA Tapes
Boine Johnson, President
Texture Technologies Corp., Scarsdale, NY

Traditionally 90 degree and 180 degree peel tests and/or tack measurements with a Polyken tact tester have been the second-generation tests following the original rolling ball test methods. Later in this presentation we will show some improvements in the peel tests, but the main thrust will be in the adhesive test methods utilizing the TA.XT2i from Stable Micro Systems of Godalming, Surrey in the UK.

Accurately Predicting High Speed Unwind
Debbie Chrzanowski, Manager Product Development & Improvement
Intertape Polymer Group, Marysville, MI

We are all familiar with customer complaints of tape with low adhesion. Upon closer examination, the customer assumption of low adhesion is sometimes a function of low roll unwind force. It is commonly known that most consumers assume that tape, which dispenses easily, or with low force, will not adhere properly. Those of us in the tape industry acknowledge the misunderstanding and, when given the chance, educate the consumer on the separate mechanics of tape adhesion and roll unwind force, or ease of dispensing.

Most pressure-sensitive tapes are "self-wound", that is, wound on themselves, without the benefit of a release liner. Therefore, the adhesive is in intimate contact with the tape's backing. When the tape is unwound, the adhesive must remain on the side to which it was applied. Thus, unwind force should be low, so as not to disturb the adhesive/backing interface. However, if the unwind is too low, the tape may have an unacceptably low adhesion to its own backing which will result in flagging when overlapped or applied to itself.

It would be ideal to supply the consumer with the same product dispensing performance (unwind condition) at all times. However, if a relationship between common in-process measurables and unwind force could be developed, the opportunity for better consistency and control would then exist.

Accurately predicting high speed unwind (HSUW) with in-process testing during the manufacturing process has always been a challenge. Only when the product has been converted into finished rolls do we know the actual unwind characteristics.

A new test method has been designed that, when used in conjunction with predetermined converting controls, will provide the opportunity to produce PSA tape products with consistent roll-toroll HSUW values.

There were 2 significant factors identified in this work, HSAB (High Speed Adhesion to Backing) and Roll Hardness, which had high correlation to HSUW. HSUW along with these two factors will be described in detail.

Advancements In Solventless Technology For Silicone Psas
Tim Mitchell, Senior Development Chemist
Dow Corning Corporation, Midland, MI

Silicone Pressure Sensitive Adhesives (PSAs) have been used for many years in areas where typical organic PSAs have failed. One of the most important uses is in applications where large temperature extremes occur. A wide variety of silicone PSAs are available on the market today and in all cases these materials are offered at 50-60% solids in an organic carrier solvent. While many organic PSAs have found alternative delivery systems (emulsion, hotmelt, etc.), industrial silicone PSAs have been slow to evolve with the times. Attempts have been made in the past to make solventless versions of an industrial silicone PSA without much commercial success. The PSA would have the tack and adhesion performance that was typical of a silicone PSA, but the high temperature shear performance was lacking. Recently, there have been advancements in silicone-based raw materials that have opened up the ability to formulate solventless silicone PSAs that have the tack, adhesion and high temperature shear performance of common solvent-based silicone PSAs. This paper will discuss the performance of past solventless attempts, current solvent-based products and a novel solventless silicone PSA (patent pending) using 180 degree peel, Polyken probe tack, Texture Analyzer, High Temperature Shear testing and Rheology testing procedures.

Revisiting Dynamic Lap Shear Method for Evaluating Tapes
Marc I. Johnson, Texture Technologies Corp.

For many decades the Static Holding Power test has been the accepted method of evaluating the shear resistance of a pressure sensitive adhesive. This method tends not only to give variable results, but they are then reported in mixed units, either as time to fall, or the amount of movement in a given time, making comparisons difficult. What is proposed in the conversion of this test to a dynamic one, by determining the force required to disentangle the molecular structure at a very slow rate. The proposed method is fully explained and examples given.

Designing Silicone Psas - A New Look At Resin [2002]
Roy M. Griswold, Sr. Chemist, Mary Krenceski, Materials Technologist, Jeffery Wengrovius, Principal Chemist
GE Silicones, Waterford, NY

Silicone pressure sensitive adhesives (PSAs) were introduced into the market in the mid-1950's and have seen enhanced properties developed to meet increasing performance demands. The subject of this paper is the use of the Six-Sigma approach, focused on the role of low molecular weight, highly condensed silicone resin in determining PSA performance. Statistical software is used to design a PSA with improved adhesive tack and peel adhesion properties. Supporting data from dynamic mechanical thermal analysis and a Texture Analyzer are used to understand the silicone PSA behavior.

A Test Method To Evaluate The Viscoelastic Properties Of Pressure Sensitive Adhesives Using A Texture Analyzer
Nattakarn Hongsriphan, Graduate Student; Carol M. F. Barry, Associate Professor; Joey L. Mead, Associate Professor
University of Massachusetts Lowell, Lowell, MA

A test method employing the Texture Analyzer was developed to evaluate the viscoelastic properties of pressure-sensitive adhesives. Dynamic testing of coated substrates was performed using the “cycle until count” mode and measurement of compression force. The available frequencies were 1 to 7 Hz, and the strain and temperature were varied from 0 to 25% and -10 to 120°C, respectively. Adhesive-substrate interactions were examined for several substrates. Results were assessed using single point data, Lissajou figures (stress-strain curves), and derived dynamic mechanical properties. Time-temperature superposition curves were developed from the single point data. Lissajou figures facilitated examination of adhesive hysteresis at various test conditions. Since the “cycle until count” mode effectively imposed a sinusoidal strain on the adhesive sample, the storage and loss moduli generated with new method was compared with dynamic mechanical properties obtained from conventional oscillatory shear.

Rubber-Acrylic Hybrid Pressure Sensitive Adhesives
Paul Foreman, Senior Scientist; Patrick Eaton, Project Supervisor; Smita Shah, Senior Research Chemist
National Starch and Chemical Company, Bridgewater, NJ

During the early years of the pressure sensitive industry, formulation of a rubber elastomer together with a tackifying resin was the dominant adhesive technology. Building on years of experience and assisted by the development of new materials, skilled formulators have developed the technology to fill a wide variety of needs from removable to repositionable and permanent adhesives. They find application in numerous end uses. If one were to name the two outstanding properties of most rubber-resin adhesives these would be versatility in adhesion, particularly to low energy adherends such as polyolefins, and aggressive tack. They have excellent 'thumb appeal'. While adhesion scientists may sometimes be tempted to discount the importance of this, it is undeniably a factor in consumer perception of performance. The Achilles heel of these products is generally their color and lack of long term durability due to oxidation and exposure to sunlight. Of course, wherever short term use is intended and color is not a factor, these deficiencies may be outweighed by the advantages of rubber-resins. While it is possible to formulate rubber-resin adhesives from low color, hydrogenated materials thus overcoming these problems, the excellent balance of adhesive properties is sacrificed.

Acrylic pressure sensitives are in many ways the complement to rubber-resin systems. First introduced to the merchant adhesive market in 1957, they have steadily replaced and overtaken the rubber-resin systems. The reason, of course, is performance and value in use. They produce colorless, optically clear films with outstanding resistance to environmental degradation. They adhere well to many substrates and have a good overall balance of adhesive properties. They are, however, generally weak in the areas of low surface energy adhesion and tack (unless a significant compromise in cohesive strength is made), i.e. precisely the areas in which rubber-resins stand out.

We shall now discuss approaches to resolving this dilemma which have led us to introduce an exciting hybrid polymer technology capable of giving us the most desirable features of the acrylics and the rubber formulations in a single material.

Epoxy Functionalized Acrylic Pressure-Sensitive Adhesives for Pendent Rosin Tackifiers and Anchoring Effect on Adhesion Performance
Jin-Hee Park, Hyun-Joong Kim
Laboratory of Adhesion & Bio-Composites, Program in Environmental Materials Science, Seoul National University, Seoul 151-921, South Korea

Use Of Marble Sludges As Filler For Thermoset Coatings To Reduce The Breaking Of Marble Tiles
Verónica Morote-Martínez, José Miguel Martín-Martínez
Adhesion & Adhesives Laboratory, University of Alicante, 03080 Alicante, Spain

Adhesion Failure Mechanism between Hot-dip Galvanized Sheet and Mastic Sealer for Automobile
Dong-Hyuk Lim1, Jin-Hee Park1, Hyun-Joong Kim1, Young-Geun Kim2
1Laboratory of Adhesion & Bio-Composites, Program in Environmental Materials Science, Seoul National University, Seoul 151-921, South Korea
2Surface Technology Research Group, POSCO, Gwangyang-si, Jeonnam, 545-090, South Korea

Stimuli Responsive Pressure Sensitive Adhesives
Yadunandan L. Dar, Wendy Yuan-Huffman, Allison Xiao, Smita Shah, Donna Huang, and Ed Hartmann
Corporate Research, National Starch and Chemical Company, 10 Finderne Avenue, Bridgewater, NJ 08807

Contribution Of Relaxation Processes Into Pressure Sensitive Adhesion Of Interpolymer Complexes
Mikhail Novikov,1, Tatiana Kiseleva1, Julia Anosova1, Parminder Singh2, Gary W. Cleary2 and Mikhail M. Feldstein1
1A.V. Topchiev Institute for Petrochemical Synthesis, Russian Academy of Sciences, 29, Leninsky pr., 119991, Moscow, Russia.
2Corium International, Inc., Redwood City, California, USA

Preparation of SIS/SBS-based UV-crosslinkable Pressure Sensitive Adhesives using Thiol-ene Reaction
Dong-Hyuk Lim1, Hyun-Sung Do1, Hyun-Joong Kim1*, Jung-Suk Bang2, Goan-Hee Yoon2
1 Lab. of Adhesion and Bio-Composites, Program in Environmental Materials Science, College of Agriculture and Life Sciences,Seoul National University, Seoul 151-921, South Korea
2 Vixxol A&C Co., Inc., Ansan 425-110, South Korea

MF/PVAc Hybrid Resins on the Adhesion for Surface Materials of Building Interior Materials as Environmental-friendly Adhesive in Under Heating System
Sumin Kim and Hyun-Joong Kim
Lab. of Adhesion & Bio-Composites, Program in Environmental Materials Science, Seoul National University, Seoul 151-921, South Korea

Synthesis of Hydrogenated Rosin Epoxy Methacrylate and Acrylic Copolymers Bearing Type II (benzophenone) Photoinitiators and Application as a Reactive Tackifier and UV-crosslinkable Acrylic Pressure Sensitive Adhesives
Hyun-Sung Do, Jin-Hee Park and Hyun-Joong Kim
Lab. of Adhesion & Bio-Composites, Program in Environmental Materials Science, Seoul National University, Seoul 151-921, S. Korea

Adhesion Performance and UV-curing Behavior of UV-polymerizable Acrylic Pressure Sensitive Adhesives for Dicing Tape
Hyun-Sung Do, Young-Jun Park and Hyun-Joong Kim
Lab. of Adhesion & Bio-Composites, Seoul National University, Seoul 151-921, S. Korea

Adhesion Performance and Viscoelastic Properties of UV-crosslinked SBS-based Hotmelt PSA: Effects of Photocrosslinker
1Dong-Hyuk Lim, 1Hyun-Sung Do, 1Hyun-Joong Kim†
2Jung-Suk Bang and 2Goan-Hee Yoon
1Lab. of Adhesion & Bio-Composites, Major in Environmental Materials Science,
Seoul National University, Seoul 151-921, S. Korea
2Vixxol Corporation, Ansan 425-833 S. Korea

Behavior Of Pressure Sensitive Adhesives From Blends Of Acrylic Block Copolymers And Homopolymers
Carlos A. Barrios, Mark D. Foster The Maurice Morton Institute of Polymer Science
The University of Akron, Akron, OH, 44325-3909

Synthesis and Characterization of Acrylic Emulsion Pressure Sensitive Adhesives Reinforced with Nanoclay
Young-Jun Park, Hyo-Sook Joo, Soungtaek Hong and Hyun-Joong Kim
Lab. of Adhesion & Bio-Composites, Seoul National University, Seoul 151-921, S. Korea

Preparation and Characterization of Water-soluble Acrylic Pressure Sensitive Adhesive
Hyun-Sung Do, Young-Wook Song and Hyun-Joong Kim
Lab. of Adhesion & Bio-Composites, Seoul National University, Seoul 151-921, S. Korea

Adhesion Performance and Thermal Curing Behavior of Self-curable Acrylic PSA using Glycidyl Methacrylate
Hyun-Sung Do, Jin-Hee Park and Hyun-Joong Kim
Lab. of Adhesion & Bio-Composites, Seoul National University, Seoul 151-921, S. Korea

Effect Of Stress Relaxation In The Course Of Adhesive Joint Formation On Adhesive Properties Of Pressure Sensitive Adhesives
Mikhail B. Novikov, Julia V. Anosova and Mikhail M. Feldstein
A.V. Topchiev Institute for Petrochemical Synthesis, Russian Academy of Sciences,29, Leninsky prosp., 119991, Moscow Russia

SATAS, D. (1998). Pressure sensitive adhesives and gels. Proceedings of the 21st Annual Meeting of the Adhesion Society, 320-321

JACKSON, M. L., LOVE, B. J. & HEBNER, S. R. (1998). Structural and electrical performance of environmentally exposed water-based epoxies. Proceedings of the 21st Annual Adhesion Society Meeting, Savannah, February 22-25, 1998.