Oxygenated Solvents From Dow Offer Coatings Formulators Non-HAPs, Low VOC, Cost-Effective Alternatives
Midland, MI - The Dow Chemical Company's ("Dow") Oxygenated Solvents business will feature its UNOXOL Diol, the latest addition to the world's largest portfolio of oxygenated solvents, as well as UCAR n-Alkyl Propionates, at the International Coatings Expo (ICE) this week in New Orleans.
UNOXOL Diol
This new cycloaliphatic diol from Dow is an approximate 1:1 mixture of (cis, trans) 1,3-cyclohexanedimethanol and (cis, trans ) 1,4-cyclohexanedimethanol. Because of its unique structure and composition, UNOXOL Diol is a liquid at room temperature. It contains two primary hydroxyl groups that lead to excellent reactivity during the preparation of condensation polymers and curing of the polymers with typical melamine and polyisocyanate crosslinkers.
Condensation polymers can be prepared from the new cycloaliphatic diol resulting in low viscosity, excellent solubility in organic solvents, and resistance to crystallization. Thermoset coatings prepared from these condensation polymers have an extraordinary balance of hardness and flexibility compared with traditional coatings. As a result of its cycloaliphatic structure, UNOXOL Diol also imparts excellent acid etch resistance and hydrolytic stability. The new diol affords all the benefits of the cycloaliphatic backbone structure, while removing the limitations to incorporation, solubility storage and usage observed when using the 1,4 isomer alone.
UCAR n-Alkyl Propionates
The UCAR n-Alkyl Propionates family includes UCAR n-Propyl Propionate, UCAR n-Butyl Propionate and UCAR n-Pentyl Propionate. These three products encompass a range of evaporation rates – from fast to slow – making them suitable for a variety of applications. Typical applications for coatings formulated with alkyl propionates are automotive refinish, OEM, and general industrial (can, marine, appliance, etc.) coatings.
The UCAR n-Alkyl Propionates are not listed as Hazardous Air Pollutants (HAPs) under Title III of the Clean Air Act. As a result, they are finding increased use as coatings manufacturers reformulate to meet recent and forthcoming EPA Maximum Achievable Control Technology Standards.
The strong solvency, high electrical resistivity, low surface tension, low photochemical reactivity, and the relative evaporation rates of UCAR n-Propyl, n-Butyl and n-Pentyl Propionate make them ideal candidates for use in high solids-compliant coatings. Their strong solvency results in excellent viscosity reduction, high solids and lower Volitile Organic Compound (VOC) formulations.
The low photochemical reactivity of the propionates, as measured by the Maximum Incremental Reactivity scale, makes them excellent candidates for compliance with recent regulations in California establishing VOC limits based upon reactivity. High electrical resistivity provides the formulation latitude to attain excellent transfer efficiency and wrap-around for electrostatic spray-applied coatings. Low surface tension provides improved substrate and pigment wetting action. UCAR n-Propyl, n-Butyl and n-Pentyl Propionates also have lower odor threshold values than acetate esters, such as n-butyl acetate or oxo-hexyl acetate, as well as many ketones.
Formulating Versatility
UCAR n-Propyl Propionate is a fast evaporating ester that may replace xylene, butyl acetate, isobutyl acetate, MIBK, t-butyl acetate, V&PM naphtha, or ethyl acetate. It has an extremely low odor and provides effective viscosity reduction.
UCAR n-Butyl Propionate is a moderately fast evaporating ester that may replace xylene, MAK, MIAK, cyclohexanone, MAAC, and PCBTF. It exhibits stronger solvency and appropriate volatility for high-solids coatings and printing ink applications, and high electrical resistivity for electrostatically-sprayed coatings.
UCAR n-Pentyl Propionate is a slow evaporating ester that has found widespread use as a replacement for Exxate 600. In addition, it may replace DBE, 2-ethylhexyl acetate and diacetone alcohol. Its linear structure provides enhanced diffusion during film formation, which results in improved surface appearance. Its high boiling point makes it an excellent polymerization medium for high-solids acrylic resins. Resin solutions prepared in UCAR n-Pentyl Propionate have low molecular weights, narrow molecular weight distributions, lower viscosities, and excellent clarity.
SOURCE: The Dow Chemical Company