Page 344 - Handbook of Adhesives and Sealants

302 Chapter Eight

TABLE 8.6 Advantages and Limitations of Rubber, Acrylate and Silicone Pressure
Sensitive Adhesives 5
Chemical family Advantages Limitations
Rubbers ....... Good flexibility Low tack and adhesion
(without additives)
High initial adhesion (better than
acrylics) Poor aging, subject to yellowing
Ease of tackification (with Limited upper service
additives) temperature use
Lowest cost Moderate service life
Good shear strength
Good adherence to low- and high-
energy surfaces
Suitable for temporary or
permanent holding
Acrylates ...... Good UV resistance Poor creep resistance
(compared to rubbers)
Good hydrolysis resistance (better
than rubbers) Fair initial adhesion
Excellent adhesion buildup Moderate cost (compared to
rubbers, silicones)
Good solvent resistance
Good temperature use range ( 45
to 121 C, or 50 to 250 F)
Easier to apply (than rubbers)
Good shear strength
Good service life
Silicones ....... Excellent chemical and solvent Highest cost (compared to
resistance rubbers, acrylates)
Wide temperature use range ( 73 Lack of aggressive behavior
to 260 C, or 100 to 500 F)
Good oxidation resistance
Good adherence to low- and high-
energy surfaces

characteristics of these various methods of applications for elastomeric
pressure sensitive adhesives. Thermoplastic elastomers are usually
employed in hot melt pressure sensitive adhesives.
Most pressure sensitive adhesives are applied to plastic, paper, foil
or fibrous material as suitable backings. Pressure sensitive tapes are
made with adhesive on one side or on both sides (double faced tape).
Double faced foam tapes are available to suit applications where sub-
strates have surface irregularities, contours, and significant gaps in
the joint area.
Several very high bond strength adhesive tapes have been developed
for semi-structural applications. 13,14 Use of foam carrier provides not