A quaternary ammonium antistat that goes off the market is replaced on four numbers: active content, carrier and its hydroxyl contribution, form and viscosity, and the dose the old formulation ran. Match those in your own system, confirm resistivity on the cured part at 12 percent and 50 percent relative humidity, and the substitution is done. A name-for-name swap is not available, because no two suppliers publish a validated equivalence.
Quat is short for quaternary ammonium compound, an ammonium salt with four alkyl groups on the nitrogen and a permanent positive charge. In polyurethane, quats are the additive route to static control in foam, in shoe soles and in cast parts.
What the old additive was doing
A cationic antistat does not conduct through the bulk of the part. A share of the molecules migrates to the surface and orients there, hydrophobic tail in the polymer and hydrophilic head at the air, and the head draws a very thin water film out of the air. The ionic additive and the adsorbed water form an electrolyte at the surface, and that electrolyte is the path the charge takes. The volume of the part is the reservoir that keeps the surface supplied, which is why an additive that is non-permanent by mechanism typically holds its effect for years in service.
The active has to reach the surface, so its concentration in the part and its mobility in that polymer set the result. The reading depends on humidity, so a replacement qualified only at 50 percent relative humidity is not qualified. And the effect builds over days as migration proceeds, so a reading taken straight out of the mold understates the part.
The four numbers to match
Active content. The Deuteron LE grades carry the same tetraalkylammonium ethyl sulphate active at 100 percent (LE 100 LV), 85 percent in a glycol (LE 829 in 1,4-butanediol, LE 151 in 1,2-ethanediol), 80 or 50 percent in butanol (LE 80, LE 50), or 50 percent on silica (LE 15P). If the old grade was, say, 85 percent active and you ran it at 2 percent, the same 1.7 percent of active is the first point on the new ladder.
Carrier, and what it brings into the cross-link. In a reactive polyurethane the carrier is not inert. 1,4-butanediol is a chain extender, and LE 829 carries a hydroxyl value of approximately 180 that Deuteron says has to be counted to keep the cross-linking right. Butanol in LE 50 contributes about 11.5 percent OH content. LE 100 LV contributes nothing. Read the hydroxyl value on the old data sheet and the new one and rebalance the isocyanate index, or choose the carrier-free grade and leave the stoichiometry alone.
Form and viscosity. A 400 mPa.s liquid meters where a 3,500 mPa.s liquid does not, and a powder goes where no liquid can. LE 829 at 400 mPa.s and LE 50 at 20 mPa.s dose by pump; LE 100 LV at 3,500 mPa.s takes gentle warming below 40 degrees C if it has thickened in a cold store; LE 15P is a free-flowing powder that releases its active under shear.
Dose. Deuteron's data sheet ranges are 0.2 to 5 percent for LE 100 LV, 0.3 to 4 percent for LE 50, 1 to 5 percent for LE 15P, and a worked example of 2.5 percent for LE 829 on a polyester foam compound at 0.6 g/cm3, which gave under 50 megohm and met EN 344. Start the ladder at the active-equivalent of the old dose and read up and down from it.
| Grade | Active | Carrier | Hydroxyl contribution | Viscosity | Data sheet dose |
|---|---|---|---|---|---|
| Deuteron LE 829 | 85 percent | 1,4-butanediol | OH value approx. 180 | approx. 400 mPa.s | 2.5 percent worked example |
| Deuteron LE 100 LV | 100 percent | none | none | approx. 3,500 mPa.s | 0.2 to 5 percent |
| Deuteron LE 50 | 50 percent | 1-butanol | approx. 11.5 percent OH content | approx. 20 mPa.s | 0.3 to 4 percent |
| Deuteron LE 15P | 50 percent | silica, 18 microns | none | powder | 1 to 5 percent |
Send us the old data sheet
With the discontinued grade's active content, carrier and your dose we will name the LE grade to start from and ship a sample from US stock.
Request a SampleCompatibility before the batch
Quats are cationic. They are compatible with non-ionic and cationic systems, and their compatibility with anionic systems is limited. The bench test is a mixing test: combine the additive with the polyol side or the emulsion at the intended ratio and look for a kick-out. Where incorporation is slow, a pre-dilution in a compatible solvent helps; Deuteron's compatibility chart for the ethyl sulphate quats covers water, isopropanol, butanol, butyl acetate, propylene carbonate, acetone, toluene, xylene, butyl glycol and butanediol. In highly non-polar media such as mineral oil the quat separates over time and the chemistry is not recommended.
The trial
Cast or foam the part at three doses bracketing the active-equivalent of the old level. Cure it fully. Measure surface resistance with a ring electrode and volume resistance through the part per IEC 61340-2-3, or point-to-point per IEC 61340-5-1, using whichever method the specification quotes. Read after conditioning at 50 percent relative humidity and 23 degrees C, then again at 12 percent, and read again after a week, because the surface keeps charging with additive as migration proceeds. Check what the part has to keep: hardness, tensile, tear, color and clarity, and for a roller the surface finish and the grind. The lowest dose that holds the number at 12 percent humidity after a week is the formulation.
What not to assume
That a grade in the same chemical family is a drop-in. Two tetraalkylammonium ethyl sulphates from two suppliers can differ in chain distribution, active content and carrier, and the carrier alone changes the cross-link. That a foam dose transfers to a cast elastomer: the published LE 829 example is a foam figure, and neither Deuteron nor P.A.T. has published cast-elastomer data. That a 50 percent humidity reading is the specification: it is the easy one. And that a supplier's silence on long-term behavior in a specific elastomer is data. Where the question matters to a part, P.A.T. puts it to Deuteron for that system rather than answering from a foam data sheet.
Antistatic additives from US stock
Deuteron LE 100 LV and LE 829 ship from our US warehouse. The other LE grades are supplied to order.
See the antistatic additives rangeFrequently asked
Is Deuteron LE 829 a replacement for Catafor CA-100?
Formulators who ran Catafor CA-100 ask us this, and both are quaternary ammonium antistats for polyurethane, which is why. P.A.T. has not run a validated comparison and Deuteron has not published one, so treat the swap as the trial above: match active content, carrier and hydroxyl value, then confirm resistivity on the part. LE 829 is carried in 1,4-butanediol with a hydroxyl value of approximately 180 and enters the cross-link. Cross-references to other suppliers' grades are available on request.
What replaced Deuteron LE 947?
LE 829 is the grade Deuteron supplies in that position. Review an old formulation calling for LE 947 against the LE 829 data sheet, and check the hydroxyl value first.
Can I use the carrier-free grade instead of a glycol-carried one?
Yes, and it is the choice when the system will not accept an added hydroxyl. LE 100 LV is 100 percent active with no carrier, so the isocyanate index stays where it was. It is more viscous at about 3,500 mPa.s, and it can be post-added to correct a batch.
How long until the antistatic effect shows?
The surface has to be populated by migration, so the reading improves over days after cure. Qualify on a reading taken after a week, not on the day of the pour, and take it at 12 percent relative humidity as well as 50.