Stepan Company: Innovative and Sustainable New Products for Crop Protection

Increasing regulatory pressure on many traditional co-formulants has been an ongoing challenge facing formulators for years. Examples range from the early phase out of chemistries including nonylphenol ethoxylates (NPE) and N-methylpyrrolidinone, to the more recent pressure on tallow amine ethoxylates and tristyrylphenols that have been under increasing scrutiny.  The challenges that formulators face will undoubtably become further complicated by the implications of the European Chemicals Agency’s (ECHA) pending microplastics regulation.  While the intent of the legislation is focused on the removal of microplastics from crop protection products, many in our industry view the imminent law as the first step toward a larger sustainability initiative and the use of biodegradable products whenever feasible.  Given that so many crop protection companies are global, they will need to source sustainable inert ingredients for use in new agrochemical formulation development, as well as reformulate existing products away from problematic components and microplastics.  When factoring in other mega trends like reduced pesticide use or an increase in organic farming, there is a clear need for new co-formulants that meet the growing challenges of today.
 
Stepan Agricultural Solutions is dedicated to providing innovative products that have outstanding performance and unique sustainability benefits.  While “sustainability” is a broad term with many meanings and interpretations, our technical development has focused on sustainable products through the following criteria:

1) removal of aromatic and high VOC (volatile organic compound) solvents,

2) removal of water to make concentrated products for more efficient for transport,

3) high bio-renewable carbon index, (BCI)*

4) products that enhance the efficacy of actives to allow improved control and potential reduction in pesticide utilization, and

5) products that improve compatibility to enable labor savings for farmers.
 
Herein we report four recent products that each have their own sustainability benefits, are readily biodegradable and compliant with pending microplastics regulations.

STEPFAC^™ 8181 PT3K is a novel, 100% active phosphate ester potassium salt that is designed for use as a dispersant in oil dispersion (OD) formulations.  Neutralized phosphate esters with “hard” counterions such as sodium or potassium are typically available only in diluted form due to how they are made and to avoid gel phases that are common above a 30 – 40% actives level. Stepan Company’s unique manufacturing process allows us to produce a 100% active potassium-neutralized phosphate ester, thereby eliminating the use of water and providing formulators with a valuable addition to their toolbox.

ODs remain among the most difficult formulations to develop, mostly due to challenges in maintaining stability that are exacerbated by a general lack of co-formulant options, especially sustainable, oil soluble dispersants.  The unique structure and potassium counterion of STEPFAC 8181 PT3K combine to make a highly effective dispersant that helps maintain stability of the OD concentrate.  As an added benefit, STEPFAC 8181 PT3K promotes good emulsion stability and high electrolyte tolerance when the formulation is diluted in a spray tank, allowing for uniform coverage.

As part of Stepan’s corporate sustainability objectives, we are committed to reducing water usage in our products and processes, and providing technologies that enable our customers to do the same.  As a 100% active product, STEPFAC 8181 PT3K offers the sustainability benefit of containing zero water, the potential to reduce pesticide application usage, and use less water in the field due to its improved compatibility.

HALLCOMID^® 1025 is a metathesis-derived C10 dimethyl amide.  Derived from vegetable oil, HALLCOMID 1025 has a BCI of 83; meaning 83% of the carbons in the product are from a naturally derived source.  This readily biodegradable compound contains amide and terminal olefin functionalities to impart unique solvent functionality (see Figure 1).  Additionally, it is non-flammable, has a low vapor pressure, a mild, low odor, and low pour point.  With these advantages, combined with a Kauri-butanol value over 1000, this solvent can solubilize a wide range of actives to create stable, safer formulations.

Figure 1. Structure of HALLCOMID 1025 (N,N-dimethyl 9-decenamide).

A key advantage that HALLCOMID 1025 offers is better cold temperature stability over its saturated analog.  The terminal double bond lowers the pour point of HALLCOMID 1025 to -24°C (vs -12°C for the saturated amide), resulting in better dilution stability in cold temperatures (see Figure 2).  Additionally, the electron rich double bond increases the overall polarity of the molecule and allows for more interaction with pi electron-containing active ingredients.

Figure 2. Tebuconazole 2EC diluted into hard water. Emulsions were stored for 72 hours at 0 °C then evaluated for stability.

NINATE^® 100L, the latest addition to Stepan’s calcium salt portfolio, is a 100% active linear calcium dodecylbenzene sulfonate (CaDDBSA) supplied in dry form. CaDDBSA products are among the most widely used anionic surfactants in agrochemical formulations. Their favorability among formulators can be attributed to their excellent emulsification, less regulatory concerns compared to alternative co-formulants and widespread availability. To date, CaDDBSA products on the market have been offered in liquid flowable form that are dissolved in various solvents, e.g., 2-ethyl hexanol, butanol, aromatic solvents, etc. While this practice may allow for easier handling, solvents have obvious disadvantages including flammability, human and environmental toxicity, formulation incompatibility and are VOCs. NINATE 100L provides a more sustainable solution by eliminating the need for solvents to give formulators a cleaner product with the flexibility to use in a wider range of formulations.

Figure 3. NINATE 100L comes in flake form and can be reconstituted in a variety of solvents. In the example above, NINATE 100L is solubilized in STEPOSOL ME, which is a methyl ester of soybean oil that can be used as a replacement for aromatic solvents. 

STEPGROW^™ 90 is a new 90-10 nonionic surfactant (NIS) tank mix adjuvant. Given that the majority of 90-10 NIS products on the market still contain NPEs, this NPE-free adjuvant gives growers a more sustainable alternative.  Specially formulated for better leaf coverage and enhanced active ingredient uptake, Stepan observed increased efficacy when compared to a leading NPE-based commercial product (see Figure 4).  Additionally, STEPGROW 90 is expected to be readily biodegradable.**  

Figure 4. Field trial results comparing STEPGROW 90 to a leading NPE-containing 90-10 product.

To further our commitment in providing sustainable solutions to the market, Stepan recently completed the construction of our new Agricultural Innovation Center.

Figure 5. Stepan’s new Agricultural Innovation Center in Winder, Georgia, U.S.

Strategically located near Stepan’s manufacturing site in Winder, Georgia, U.S., the Agricultural Innovation Center is intended to facilitate collaboration with customers and further accelerate Stepan’s research and development in the agricultural industry.

The Agricultural Innovation Center will include a greenhouse for live plant testing and research, a training center for formulation development, a spray chamber for studying driftable fines, a Class II lab to support biological formulation development, and labs dedicated to liquid and dry formulation design and support.

“The Agricultural Innovation Center is a testament to our commitment to safe and sustainable agriculture, our customers’ growth and to farmers worldwide who face ever-increasing challenges that require new innovations,” says Jason Keiper, Stepan Company Chief Technology and Sustainability Officer.

The temperate climate in Georgia also will enable Stepan to test year-round, helping accelerate Stepan’s large-scale production rate and ability to bring new solutions to the market more rapidly.

Stepan recognizes the need for sustainable solutions in agriculture. There are many factors driving this trend, including regulatory changes, consumer preferences, and the increasing use of biological active ingredients and organic farming.  Going forward, Stepan is well-positioned to offer sustainable crop protection solutions and enable our customers’ growth. 

* BCI is the number of biorenewable carbons derived from plant-, animal- or marine-based sources, divided by the number of total carbons in an idealized molecule.

** Each component of this blend is readily biodegradable.

This article will be published in AgroPages '2021 Formulation & Adjuvant Technology' magazine to be published this May.

Welcome you to join this magazine to promote your products and solutions. Please contact Grace Yuan via: grace@agropages.com