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New Moisture Barrier Coatings Patent Issued to SCF

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Surface Chemists of Florida, US Patent No. 10,189,752, January 29, 2019.
Sealant compositions containing waxes are widely used as effective moisture barriers in coating applications, particularly as sealants for controlled release fertilizers. Commercially available sealant compositions are typically thermoplastic, waxy materials that are tacky above their melting points, necessitating agitation during a cooling step. This cooling step is typically carried out in a fluid bed or a rolling drum, particularly when wax based sealants or components are used in the coating process. The cooling step adds capital costs for equipment, added space, extra mixing time, and energy costs. SCF’s most recent patent provides an effective sealant that does not require a cooling step, thereby reducing costs and simplifying the sealant process.

SCF has discovered and patented moisture barrier coatings and sealants comprised of mixtures of organic wax and wax soluble polymer which are dispersed into one or more components of a thermoset polymer and form a semi-interpenetrating polymer network when the thermoset polymer is subsequently applied to and cured on a substrate. The addition of the wax and wax soluble polymer substantially improves the moisture barrier properties of the thermoset polymer, and provides an effective moisture barrier coating that is non-tacky at the cure temperature of the thermoset polymer, and thus does not require a cooling step.

Please contact Surface Chemists of Florida for more information.

Soil Release Polymer Patent Issued to SCF

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US Patent Office issues patent number 9,926,466, “Amic Acids as Surface Treatments” to Surface Chemists of Florida

Surface Chemists of Florida has patented surface treatments that are modified with polymeric or
monomeric amic acids including one or more tertiary amine functional groups. When utilized as a
surface treatment, the amic acids impart many different benefits, including hydrophilicity, soil resistance
and corrosion inhibition. Compositions and methods for treating the surfaces are also provided in the
patent.

The reduction in the use of cleaning products and the energy associated with cleaning functions have
been long-sought goals for businesses and individuals alike. One way to achieve those goals is to
increase the time required between cleanings by keeping surfaces cleaner and increasing their
resistance to dirt, soil, grease and corrosion. The improvement in the soil resistance of substrates,
including both hard surfaces and textiles, is important in that it reduces the tendency of soil material to
adhere to the surfaces, in effect slowing the rate and reducing the extent of soiling. This is also
important in that it is easier to remove the soil when cleaning the surface, particularly by reducing both
the energy and cleaning chemicals required to remove the soil. A secondary benefit of the amic acid
modified surface treatment is that they become more hydrophilic, so that water will drain from a
treated surface in a thin sheet, without breaks. This reduces the formation of water spots and streaking
when the treated surfaces are dried.

Please contact Surface Chemists of Florida for more information.

SCF Presentation at ANNA 2018

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SCF Presentation at ANNA 2018 
“Detection and Analysis of the Early Stages of Caking Onset”

SCF’s research and development engineer, Dr. Stefan Kelly, presented his work investigating the early stages of caking in prilled ammonium nitrate this past September at the 2018 ANNA conference in Calgary, Canada. This work was aimed to provide a more fundamental study of the soft-set caking behavior in ammonium nitrate.

Figure 1. Process of AN caking through saturated salt solution bridging.

Ammonium Nitrate (AN) prills, like many salt powders and granules, exhibit hygroscopic behavior, meaning they readily adsorb moisture from the surrounding environment. When AN prills adsorb enough moisture a saturated salt solution forms crystal bridges to other prills that are in direct contact. Caking of prills leads to difficulties of handling and transport, even rendering products and equipment unusable. AN prills can experience caking in the presence of moisture, pressure and erratic storage conditions.

An interesting caking phenomenon occurs called soft-set caking, which is different than typical caking which yields solid chucks or bricks of material. In the case of soft-set caking, the prills form a temporary cake after being stationary for a period (in railcars, trucks, silos, etc.). The temporary cake results in difficulty initiating flow, but once the cake is broken the prills flow freely, as usual, but then caking would return when sitting.

In his work, Dr. Kelly adapted established industry test methods as well as created new methods to add a higher degree of quantification to the study of fertilizer caking. These test methods included a sensitive means of measuring the caking forces present in soft-set phenomena under varied caking conditions.

Figure 2. Data set showing the test method sensitivity for measuring the forces in soft-set caking.

Using these sensitive test methods:

  • Optimum coating levels were determined that limit soft-set caking.
  • The effect of pressure on AN prills to induce caking at various coating levels was explored.
  • New coating formulas were examined that reduce the performance issues AN experiences when cycled through its phase transition at 32°C.