Fire-resistant paint: "Prevent the spread of fire"

Fireproof coatings can save a lot of money, and even more importantly: life. But what solutions are being used to develop this coating, how are they tested, and what are the future trends? In our interview, Klaus Bendell, from Clariant, gave some answers.
Klaus Bender is the head of Clariant's technology marketing

. He will also organize seminars for formulaters and other coating professionals on the basics of flame retardant coatings.
do we use which fire protection coating?
: "The coating is
different depending on what you want to achieve. If you want to prevent the development of fire, use a coating that prevents inflammation of building materials. This involves combustible underground, so first and foremost wood. Ignition sources, such as short circuits or discarded cigarette butts, should then be prevented. Here we have a relatively low level of demand, involving temperature effects.
we found another situation was burning, which caused the burning of building materials, office supplies and plastic. This has become a big problem in our family because we found a lot of plastic here today. Inflammation progresses relatively quickly and smoke develops more strongly. The fire then spreads through openings to other rooms, and we will soon have to deal with it, such as Grenfell Tower in London a few years ago.
want to protect the whole building from collapse in this situation, you need more powerful weapons. The expansion coating is then used to protect the steel structure. These coatings work through foaming and form protective foams in the event of a fire, providing excellent high temperature insulation.
are the raw materials used by manufacturers of fireproof coatings?
Bender
:
In the first case, ammonium polyphosphate or aluminium trihydrate (ATH) can be used when simply protecting the coating from ignition. Hydrations form water vapor, which reduces the temperature of the initial fire. Ammonium polyphosphate also forms a carbon layer on the surface and reacts with the coating composition, protecting building materials from oxygen supply and preventing further spread of flame.
expansion coatings are designed to provide passive fire protection. In order to compare: active fire prevention will be a sprinkler system. Passive fire prevention, on the other hand, is only present and works without activation in the event of a fire.
, we also found that ammonium polyphosphate is largely the main ingredient. This expansion effect then requires more ingredients, which must be precisely added to the color.
also uses halogenated flame retardants. What's the status quo here?
Bender
:
, halogenated flame retardants, whether chlorinated or brominated, still play a relatively important role, especially in plastics. In the event of a fire, halogens are separated and act as free radical sensing agents, i.e. they infest high-energy free radicals, such as hydroxyl free radicals, thus slowing the chain reaction in a fire scenario.
disadvantage is the formation of hydrogen halide, or hydrochloric acid, and other toxic gases in the event of a fire. As a result, halide fire protection agents are increasingly being observed and some have been banned. This is especially true for PU-based materials, where TCPP may no longer be used in the future. But there are some alternatives available. At Clariant, for example, we offer phosphorus-based flame retardants with the same effect.
current test method for fire protection coatings?
Bender:
tests developed to simulate a fire are as variable as the fire itself. This is first a small flame with a lure, one of which tries to ignite a small surface. Here, you usually get only a simple result and then indicate a pass or failure.
modern methods also produce a variety of physical test data, such as combustion energy or oxygen consumption. The latter is measured using a tapered thermometer, which we also use in Clariant, using a relatively small sample × of 10 to 10cm.
also requires oxygen consumption through the European SBI test (single combustion project), which is now the standard building material classification test for the whole of Europe. Old test standards and old test methods still exist. In Germany, for example, it would be "Brandschacht-Test", England's Railant Panel Test or France's Epiadiateur, and they would basically want the same thing, the burnability assessment of building materials. These tests have actually been removed from the market in order to obtain uniform tests for the whole of Europe.
from the paint manufacturer's point of view, how does the test work?
Usually
use
substrates, and people know about fire behavior, such as particleboards," Bender said. Apply varnish to it to compare coated and unpainted samples. Of course, the performance of the coating sample must not be lower than that of the uncoated sample.
it's hard to test the paint film yourself because it has to be too thick to make the results less realistic. For example, there are tests for textiles and plastics. For example, in the case of plastic, use light and then place it on the surface to see if it starts to burn or if something falls to burn. As a result, the characteristics of the test are very different and suitable for the appropriate application.
standards can be obtained and recognized globally, such as in the plastics or automotive industries. But there are also many local applications only, such as in Russia, Korea or Japan.
are their trends in fire protection coatings?
We
general
water-based formulations," Bender said. Of course, we must also provide answers in the field of flame retardants. For example, ammonium polyphosphate can also be used in water-containing systems, but special requirements already exist, such as viscosity behavior, which differs from solvent-based formulations for water-containing formulations.
in the absence of water-load systems, there is a tendency for 2K systems, for example, to have very good properties in harsh conditions. For example, in terms of durability, high requirements must be met.
interview was conducted by Jan Gesthuizen