Acrylic conditions during processing

Optimization of Cure Conditions During Processing of Acrylic Latex Coatings... 

During the history of a half century from the first discovery of the reaction (/) and 35 years after the industrialization (2-4), these catalytic reactions, so-called allylic oxidations of lower olefins (Table I), have been improved year by year. Drastic changes have been introduced to the catalyst composition and preparation as well as to the reaction process. As a result, the total yield of acrylic acid from propylene reaches more than 90% under industrial conditions and the single pass yield of acrylonitrile also exceeds 80% in the commercial plants. The practical catalysts employed in the commercial plants consist of complicated multicomponent metal oxide systems including bismuth molybdate or iron antimonate as the main component. These modern catalyst systems show much higher activity and selectivity... 

In the two-step process, the second-stage reactor is similar to the first-stage reactor but is packed with an optimized catalyst for aldehyde oxidation, based on Mo V oxides, and is run under different operating conditions. Care must be exercised during the separation and purification phases to avoid conditions favouring acrylic acid polymerization, e.g., by addition of a radical polymerization inhibitor such as the hydroquinone monomethyl ether. Selectivities to acrylic acid are higher than 90% at total conversion of the aldehyde. Overall yields referred to propylene are in the range 75-85%. Most acrylic acid produced is esterified for the production of acrylate esters. 

Softening agent and antistatic processing aid for most fibres but particularly suitable for use on acrylics. It is stable to basic dyebath conditions and can therefore be applied to acrylic fibre or tow during dyeing giving a simple economical processing route for conversion into yarn. 

Exposures to ethyl acrylate monomer are most likely to occur in an occupational environment via skin contact and inhalation. However, the closed systems used during manufacture and transportation will limit worker exposures to those that may occur during routine process maintenance, periodic plumbing leaks, and the collection of quality control samples. Under these conditions, exposures are further limited by the use of industrial hygiene controls and personal protective equipment. The acrid odor of ethyl acrylate, which can be detected at 0.001-0.005 ppm, also serves to limit exposure. Studies of monomer production workers have indicated that... 

Various types of lacquer are used, for different customers specifications. They include alkyd- and acrylic-based systems. They must, of course, be stable and volatile-free themselves, during the aluminizing process, and they must be stable under service conditions (up to 200 C). 

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