ASCOTRAN® - Eliminate flash-rusting whilst preserving the water-resistance of your waterborne coating

Blog Archive | 5 minutes  | Author: Adam Morgan , Ph.D.

What is flash-rusting and how can I prevent it efficiently, without increasing the water sensitivity of my film?

Flash-rusting is a phenomenon familiar to most waterborne coating formulators. This immediate corrosion of metal surfaces by waterborne coatings is characterised by the appearance of small rust-coloured spots on the surface of the substrate. A desire to reduce VOC content of coatings is partially responsible for driving the growth of waterborne technologies over recent years, making high-performance anti flash-rust additives of particular interest.

To meet this demand, ASCOTEC has developed a range of efficient and versatile anti flash-rust additives under the ASCOTRAN® brand. These are effective in a wide range of binder types and on many different substrates. Not only do they protect against flash-rusting but they also help to increase the lifetime of your metal packaging.

These ready-to-use liquids are film-forming additives that passivate the metal surface at very low dosages. Whilst many other anti flash-rust additives reduce the water resistance of a coating, ASCOTRAN® technology combines high-performance with hydrophobising properties.

Remember that you can submit a sample request for an ASCOTRAN® product on our product page. Alternatively, our technical sales team are on hand to assist with any enquiries (01827 314151).


What are the key benefits of ASCOTRAN® anti flash-rust additives?

ASCOTRAN® products are able to offer the waterborne coating formulator the following benefits:

  • Ecolabel compliance.
  • VOC-free.
  • In-can protection.
  • Easy to incorporate.
  • Preserves the water-resistance of the dry film.
  • Multi-metal protection.
  • Cost-effective.
  • Low use dosages.


The ASCOTRAN® product range

We always recommend speaking with Lawrence Industries’ technical sales team in order to get the best recommendation for your system. However, the table below offers a good starting point and raison d’être for each grade.

Demonstrate the performance benefit of ASCOTRAN® to me with some example systems

So, we’ve outlined the benefits - but let us look at how the ASCOTRAN® products compare in some model systems. First, it is worth highlighting the five grading criteria for anti flash-rust additive performance. In the figure below you will see the level of flash rusting required to assign a given grade of performance to the coating (Grade 0-4).

ASCOTRAN® flash-rust inhibitors work at low dosages and compete with high nitrite-containing additives. Usage of these is responsible for the formation of hazardous nitrosamines. Even when the film dries under severe humidity conditions, they perform better than most commonly used flash-rust inhibitors. In the example below the performance of ASCOTRAN® H10, H14 and H18 are ranked against three competitor grades, when added at varying dosages to a 1k waterborne acrylic DTM.

It is clear to see that ASCOTRAN® H10 and H14 have the highest performance in this series. How about in a 2k waterborne epoxy DTM?

Again, the ASCOTRAN® H14 is the best in this test series. No matter what type of waterborne coating you are formulating, we have the products and expertise to help you achieve your goals.


How can I preserve the water resistance of my film when using anti flash-rust additives?

ASCOTRAN® is different from many other flash rust inhibitors in that it combines performance with hydrophobising properties. In the two examples below, a waterborne 2k epoxy primer is tested to ASTM D870 at 40°C. This test method assesses the water resistance of coatings under water immersion conditions.

ASCOTRAN® H14 and H18 are the two best performers in this case, with perfect results obtained in both zinc-free and zinc-rich coatings respectively.

How do I protect the metal packaging of my waterborne coating from corrosion?

Brand image can be sabotaged through packaging corrosion. If you are making a high-performance coating then the packaging needs to stay in top condition as well, to meet customer expectations. The images below show the difference that ASCOTRAN® can make to the protection of your packaging.

What should I do now?

If you know the grade that you are looking for then why not put in a sample request on our ASCOTRAN® product page, or give us a call on 01827 314151. Should you need technical assistance in choosing the right product for your formulation then our technical sales team are on standby to assist you with your enquiry.
Author: Adam Morgan , Ph.D.

Adam studied chemistry at the University of Warwick for 8 years, where he obtained a Ph.D. in the field of polymer and inorganic colloid science. He has been with Lawrence Industries since 2014 as a technical sales manager covering all industry areas. He is now responsible for marketing within the company as well.