Soluble Concentrates (SL)

In SL formulations active ingredient contents between 10 – 50 % can generally be realized.

The pesticide is dissolved in water or a water-soluble organic solvent. To enhance the efficiency and efficacy of the spray mixture, penetration enhancers and wetting agents are often included. Also, water-insoluble co-formulants might be added, for example, anti-foam agents.

For a long-term stable formulation the pesticide must be resistant to hydrolysis. Especially when ionic actives are formulated, a high level of foam might be formed.

Key-factors:

  • Pesticide must be soluble and stable in water (or polar solvent)
  • No crystals must form upon storage

General recipe

SL ingredients w/v%
Active ingredient 10-50
Penetration or wetting adjuvants 5-25
Stabilizer (pH, buffer, anti flocculation agents) 0-20
Water or a water soluble solvent to 100

Products


Built in solution

Trade name Chemistry Property EPA
LUCRAMUL® AG 4802 Aqueous surfactant blend (TFA free) Compatible with glyphosate/glufosinate
LUCRAMUL® AG 4820 Aqueous surfactant blend (TFA free) Compatible with glyphosate/glufosinate
LUCRAMUL® SLES 370 Sodium lauryl sulfate Compatible with glyphosate/glufosinate
LUCRAMUL® LOFO 1 Low foaming aqueous surfactant blend (TFA free) Compatible with glyphosate/glufosinate
LUCRAMUL® LOFO 2 Low foaming aqueous surfactant blend (TFA free) Compatible with glyphosate/glufosinate

EPA can be submitted on request


Adjuvant

Trade name Chemistry Property EPA
LUCRAFOAM® L Vegetable oil based ester Liquid aqueous defoamer

EPA can be submitted on request


 

Conventional vs. Low-Foaming Surfactant Blends


Finding the best surfactants for generating efficient formulations can be difficult. Here we introduce four built-in additives for soluble concentrate (SL) formulations showing excellent results as wetting agents. Two of them (LUCRAMUL® LOFO 1 and LUCRAMUL® LOFO 2) are designed for low foam formation.

Surface tension and foam persistency was tested with spray mixtures containing 1% of the following glufosinate ammonium SL formulations:

    a.i.
(glufosinate ammonium)
Surfactant
(LUCRAMUL®)
  No. [g/l] LUCRAMUL® [g/l]
Conventional surfactants 1 200 AG 4820* 280
  2 200 AG 4802** 250
  3 400 AG 4802** 250
Low foam surfactants 4 400 LOFO 1** 250
  5 200 LOFO 2** 250
  6 400 LOFO 2** 250

* sodium laurylether sulfate (SLES) based
** alkyl poly glycoside (APG) based

The LUCRAMUL® AG types and the LUCRAMUL® LOFO types have a sufficient strength in lowering the dynamic surface tension:


 

The dynamic surface tension profiles of LUCRAMUL® AG types indicate good wetting properties, whereas a lower foam formation was observed with the LUCRAMUL® LOFO types. LUCRAMUL® LOFO 1 shows remarkably good properties in both measurements producing the lowest amount of foam and the best dynamic surface tension.

The foam volume of the formulations 4-6 containing LUCRAMUL® LOFO 1 or LOFO 2 directly after mixing is significantly lower compared to formulation 1-3 using conventional surfactants. After 30 minutes the foam volume is decreased even further.
LOFO 1 is best used for highly concentrated formulations (>35% active). For low active content LOFO 2 forms stable and efficient formulations.