Clear, flowable RTV silicone coating

ACC AS1722 is a clear, low viscosity room temperature cure silicone which can be used to seal, bond and coat sensitive electronic components. It has excellent adhesion to most substrates including plastics and will not cause corrosion of sensitive metals such as copper. It is supplied in convenient 310ml cartridges.

ACC AS1722 is a specially formulated neutral cure silicone sealant designed for use with electronic assemblies. An alkoxy 1-part room temperature vulcanising (RTV) silicone sealant, the system produces a sealant with excellent adhesion to most common substrates.

Key Features

• High clarity


• Contains UV trace for inspection


• Adhesion to many substrates

Typical Applications

• Assembly of electrical and electronic equipment


• Sealing of corrosion sensitive devices


• Shallow encapsulation of small circuits and connectors

Video - mixing and degassing LED phosphors

We just added a video to our page about the THINKY Mixing and Vacuum Degassing Machines. It demonstrates the successful mixing and dispersion of LED phosphors into a silicone resin with absolutely no air bubbles.

FIP Gaskets - Cheaper than you think?

We have just added Technical Bulletin TB2009-14 to our articles page about using benchtop robotics to lay down liquid Form-in-Place gaskets.

Optically clear silicone encapsulants

LED, photovoltaic (PV) and other light sensitive devices require UV stable, non-yellowing encapsulants for protection and improved light transmission. The table below shows a range of addition cure silicones which are temperature and moisture resistant, non-yellowing and UV stable.

Product	Hardness	Viscosity mPas	RI	Mix Ratio
OPT7020	40	4500	1.40	10:1
ACC Q-Sil 218	59	3000	1.40	10:1
ACC Q-Sil 222	59	2200	1.40	10:1
ACC QLE1102	45	1000	1.40	1:1
ACC Q-Gel 300	Gel	1000	1.40	1:1
ACC Q-Gel 301	Gel	2000	1.40	1:1
ACC Q-Gel 310	Gel	1000	1.40	1:1
ACC Q-Gel 311	Gel	1000	1.40	1:1
ACC Q-Gel 900	Gel		1.43	1:1
ACC Q-Gel 910	Gel		1.47	1:1
ACC Q-Gel 920	Gel		1.49	1:1
ACC Q-Gel 92-14-1	Gel	650	1.515	1:1
ACC Q-Gel 92-16-1	Gel	2820	1.539	1:1
ACC Q-Gel 92-18-1	Gel	5690	1.549	1:1

Of special note is ACC Q-Sil 222 which is self bonding to a wide range of substrates without the use of a primer.

These materials are technically well suited to the following applications

• LED potting


• Outdoor signage, displays and lighting


• PV module manufacture


• PV concentrator cell manufacture


• Sealing aviation displays

Check out our range of silicones from ACC and Opti-tec.

Fuel resistant silicone

Modern diesel engines require gaskets to seal a variety of components, including fuel systems and control units. RTV silicones have been used in and around the engine for many years, being chosen for their flexibility and ability to withstand high temperatures. For use within a diesel engine, the gasket material must be able to withstand the temperatures generated from the engine - but most importantly, must be able to withstand the continual contact with diesel fuel.

In general, silicone RTV sealants are prone to attack from mineral oils. To overcome this problem they can be formulated using fluorosilicone polymers; however, the dramatic increase in costs usually prohibits their commercial use.

The good news is that our sales partners ACC have taken one of their patented acetone cure RTV silicone sealants and carried out extensive testing to prove their suitability for applications involving contact with both conventional and bio-diesel fuels.

These tests proved ACC AS1810 suitable for use with conventional and bio-diesel when used as a gasket material in conjunction with mechanical fixings.

Silicones and LEDs - removing heat and enhancing light

Optics and packaging are playing an ever more important role when designing LED-based products which are both efficient and maintain performance over long periods of time. Silicone elastomers have proven themselves to be versatile in solving a variety of design and production issues. Our sales partner, ACC Silicones, have published a guide to products and applications in this growing field.

These include Optically Clear Encapsulants, a range of gels with differing cure cycles and physical properties. Together with harder silicone elastomers we can offer a product for most LED potting applications which require optical clarity. In particular, we can offer refractive index from 1.40 to 1.49, with an exciting new product available at 1.53.

Dissipating unwanted heat away from the diode to a suitable heat sink is essential for overall performance and can easily be achieved by selecting a thermally conductive silicone encapsulant. When selecting a thermally conductive encapsulant there is always a trade off between flexibility and thermal conductivity, due to the nature of the fillers used - as you raise the conductivity you will also see a rise in hardness. ACC Q-Sil 553 has been proven to provide a good balance offering reasonable conductivity whilst retaining a low modulus and hardness, thus reducing stress during the thermal cycle.

Not just flying high, cooking too

Part of our range of silicone adhesive/sealants from ACC, the Silcoset range has a long-established reputation. They are approved for use by the MOD and Rolls Royce in aerospace and other critical applications.

With high temperature resistance and good adhesion, you would expect there to be other, perhaps more conventional, applications as well. You would be correct. Silcoset 158 is the product of choice for fixing glass panels onto doors and hinges in domestic ovens.

Single part, solvent free silicone conformal coating

ACC 14 is a new silicone conformal coating which is single part, 100% solids and solvent free. The RTV (ambient temperature curing) coating has been formulated to provide protection for high specification printed circuit boards.

Key features:

• 1-part, no mixing


• Clear


• Ambient temperature cure - touch dry in 15 minutes


• Wide service temperature range (-50°C to +200°C)


• Low viscosity


• Excellent adhesion


• Excellent resistance to solvents, humidity and mould


• Solvent free, 100% solids content


• No shadowing effect

It can be applied by dip, spray coating, selective spray applicators, and flooding. No solvent dilution is required to achieve application viscosity. And, it's pretty safe to use! No flash-proof equipment needed, and there are no risk or safety phrases associated with it.

Let us know if you need it!

Good conductivity

We have just updated the website with a Technical Bulletin describing the case for silicone conductive compounds, and why they have so many applications.

One product fairly new to the range is ACC AS1806, which is a single part thermally conductive silicone adhesive. It is a black paste, with a fast, neutral cure and good adhesion. It has an excellent thermal conductivity of 1.55 W/m·K.

It is used for electronics applications in aerospace, under bonnet automotive, consumer products and LED applications. Because of its neutral cure and the absence of any harmful by-products, ACC AS1806 is a perfect replacement for conventional oxime based silicone adhesives. A self-levelling version, ACC AS1803, is also available.

Silicone in a bag

To complement our successful range of silicone encapsulants and potting compounds, we have introduced these new, easy to use, twinpack sachets.

The small pack size (250g) makes this the affordable solution for users who want to avoid the use of scales and mixing equipment.

Simply remove the clip, mix and pour. Standard products include ACC Q-Gel 310, ACC Q-Gel 301, ACC Q-Sil 550, ACC Q-Sil 553 and ACC Q-Sil 216.

• Clean & Simple to use


• Minimum wastage


• No external mixing equipment needed


• Guaranteed correct mix ratio