Acrylate adhesives vs. silicone adhesives
Silicone and acrylate adhesives are the adhesives most commonly used in polyimide tapes. Polyimide tapes consist of two layers: – the polyimide film and the adhesive that is applied to this film.
Although silicone adhesives are most commonly used for the adhesive layer, many applications require the tape to have an acrylic adhesive. You can only understand why this is the case if you compare the two types of adhesive – the silicone and the acrylate adhesive.
Silicone adhesives - The properties
Silicone offers better elongation at break. It is used for electrical insulation of electrical devices. Because it offers the highest heat resistance among adhesives, it is also commonly used for high-temperature insulation. Some of the characteristics of silicone tapes are listed below for better understanding.
- Silicone is highly flexible at sub-ambient temperatures.
- It can provide consistent performance over wide temperature ranges.
- It has very good aging and UV resistance.
- It can withstand high temperatures.
- Silicone also shows good resistance to polar solvents.
Acrylate adhesives – The properties
There are two types of acrylic adhesives: water-based and solvent-based. Water-based acrylic adhesives dry slower compared to solvent-based adhesives. However, solvent-based acrylic adhesives usually have better resistance to other solvents, chemicals and water. Some of the properties of acrylate adhesives are as follows.
- Acrylic adhesives have reasonable adhesion to a variety of substrates.
- It has good aging, transmission and UV resistance suitable for fiber optic applications.
- It also has reasonable temperature resistance but is not as good as silicone adhesives.
- It has a lower stickiness, which means it is less sticky after drying.
A comparison of acrylate vs. silicone adhesives
Now that we know the properties of silicone and acrylic adhesives, we can proceed to compare the two types of adhesive.
Silicone adhesives can withstand a higher temperature range compared to acrylic adhesives. Acrylic adhesives have the property of being more brittle and can therefore break even at extremely low temperatures. In general, acrylic adhesives bond better at medium temperatures, ie in a temperature range between 0°C and 100°C. On the other hand, silicone adhesives have better adhesion at lower temperatures, ie below 0°C, as well as at higher temperatures, ie above 100°C.
So it seems that silicone adhesives are rather standard and preferred for most applications. However, in some situations where silicone cannot be used, one has to resort to acrylic adhesives. As for the point of lower tack with pure acrylates, again there is an alternative for better performance. Modified acrylic or rubber adhesives can be used for better tack. Pure acrylate adhesives are commonly used for adhesive tapes that are used for bonding, sealing or surface protection.
