Silicone Adhesive Tapes
2011- Silicon and acrylic adhesives are those
widely used in Polyimide tapes. In fact, the polyimide tapes have two
layers- the polyimide film and the adhesive that is applied to that film.
Although silicon adhesives are mostly used for the sealant layer, many
applications require the tape to have acrylic adhesive. Why is this so can
be only understood by comparing both the types of adhesives- the silicon and
the acrylic adhesives.
Silicon Adhesives- The Characteristics
Silicone offers better
elongation at break. It is applied for electrical insulation of electrical
equipment. As it offers the highest heat resistance among film adhesive
tapes, it is also widely used for high temperature insulation. Some of the
characteristics of silicon adhesives are listed below for better
- Silicone is highly flexibile at sub-ambient temperature.
- It can give consistent performance over wide ranges of temperature.
- It has very good aging and UV resistance.
- It can withstand high temperature.
- Silicone also shows a good resistance to polar solvent.
Acrylic Adhesives- The Characteristics
Acrylic Adhesive Tapes
two types of acrylic adhesives water-based and solvent-based. Water-based
acrylic adhesives dry slowly as compared to solvent based adhesives.
However, usually solvent-based acrylic adhesives show better resistance to
other solvents, chemicals and water. Some of the characteristics of acrylic
adhesives are as follows.
- Acrylic adhesives have a reasonable adhesion to a wide range of
- It has a good aging, transmittance and UV resistance that are
suitable for fiber optic applications.
- It also shows a reasonable temperature resistance but not as good as
- It has a lower tack meaning it sticks less when dry.
Acrylic vs Silicone Adhesives
Now when we know the
characteristics of both - silicone and acrylic adhesives, we can move on to
compare both the types of adhesives.
Silicone adhesives can withstand higher temperature range as compared to
acrylic adhesives. Acrylics have the property of being more brittle and as
such they can crack at extremely low temperatures too. If we take the
general view, acrylic adhesive have better adhesion at mid-range
temperatures which means a temperature range that falls within 0°C to
100°C. On the other hand, silicone adhesives have higher adhesion at
lower temperatures that is under 0°C as well as at higher temperatures
that is above 100°C.
As such, it seems that silicone adhesives are more standard and preferred
for most of the applications. However, some situations where silicone can
not be used, one has to depend on acrylic adhesives. As far as the point of
lower tack in pure acrylics is concerned, it has an alternative too for
better performance. Modified acrylic or rubber adhesives can be used for a
better tack. Pure acrylic adhesives are commonly used on tapes which are
used for bonding, sealing or surface protection.