There are important advantages related to the latex properties that can be achieved with a semi-batch process, and more specifically a starve-fed process, which is simply a semi-batch process where the monomer concentration inside the polymer particles is kept very low by keeping the monomer feed rate to the reactor low.
Specialty chemicals provider Archroma has entered an agreement with specialty raw material distributor Van Horn, Metz & Co. for the distribution of its Mowilith emulsions in the United States.
Polly Mertz's new emulsion batch was delayed due to some of the ingredients freezing when left overnight on the dock. Polly, eager to start her batch scale-up, had approved placing the drums in a steam-heated room in the plant to allow for warming and easy pumping. What was the material that caused the problem, and what mistake had Polly made in heating up those frozen drums?
Al Kidd's first sign of a problem was the strong, acrid smell that burned his nose. What was the material in the drum that caused the smoke? What had caused the material to react so violently?
When added to varnishes and other coatings, Michem Emulsion 62330, a fine-particle-sized emulsion, provides gloss with excellent water repellency, corrosion and block resistance, and lubricity.
This work demonstrated that through the use of a single surfactant, Calfax 16 L-35, a simple emulsion polymerization process can generate 45% hydrophobic latex with particle size in the range of 100-150 nm at a conversion rate of >98% at the end of a 4-hr reaction, without a chase process.
The combination of a high-Tg, hydrophobic, high-MW alkyd with the proper surfactants and levels can produce a highly corrosion-resistant DTM alkyd emulsion when formulated with select pigment dispersants.
AgriEsters (methyl soyate, palm and coconut esters) are a new, low-cost alternative that can help emulsify old solvent-based resins (bead acrylics, oil-based alkyds and polyterpenes), giving formulators new alternatives.
