Polyvinyl acetate biocide

Microbiocides are an essential ingredient of maity paints. Usually a combination of products is required to assure complete protection. The development of a singlecomponent biocide for paints - Bayer s Preventol TP OC 3082, which is particularly suitable for outdoor aqueous emulsion paints based on polyvinyl acetate, pure aciylate or styrene acrylate - is described. 

Uses Fungicide, algicide, biocide for exterior paints, coatings, caulks, stucco, acrylic, vinyl-acrylic, or polyvinyl acetate latexes Features Broad spectrum nonleaching noncorrosive to metals stable to radiation compat. with latex polymers contg. zinc oxide Properties Off-wh. aq. disp. si. odor sp.gr. 0.95 f.p. -5 C Use Level 5-20 lb/100 gal (exterior paint)... 

Biocides are generally formulated with a carrier into concentrations of 2 to 10% active ingredient. They are available to plastics converters, processors, and other users in powder, hquid, or sohd pellet form. The carrier, as noted previously, is usually a plasticizer, but it can also be a resin concentrate such as PVC/PVA (polyvinyl acetate) copolymer or polystyrene. For example, OBPA, the most common biocide active ingredient, is typically purchased as a dispersion in a plasticizer at a concentration of 2% active ingredient. 

Dried polyvinyl acetate adhesive films are highly resistant to attack by microorganisms. The addition of biocides will prevent attack of microorganisms on a liquid emulsion or on a dried adhesive film when animal or vegetable modifying ingredients have been added to the emulsion. 

Many polyvinyl acetate emulsions can be used as adhesives without modification. However, an adhesive is usually compounded in order to tailor the product for a particular application. Compounding of adhesives facilitates application on equipment and bonding on specific substrates. It also imparts resistance to ambient conditions. In addition to film formers, an adhesive usually contains some of the following components plasticizers, viscosity/rheology modifiers, tackifiers/extenders, solvents, fillers, humectants, surfactants, and biocides. 

Biocides are required when animal or vegetable substances or their derivatives (starches, casein and other proteins, nut shell flours, sugar, and cellulosic resins) are incorporated into polyvinyl acetate homo- or copolymer emulsion adhesives. Growing microorganisms digest these substances and can generate foul odors, discolor the adhesive, lower its viscosity, and weaken the bond. 

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