Acrylic latex exterior performance

AH-acryHc (100%) latex emulsions are commonly recognized as the most durable paints for exterior use. Exterior grades are usuaHy copolymers of methyl methacrylate with butyl acrylate or 2-ethyIhexyl acrylate (see Acrylic ester polymers). Interior grades are based on methyl methacrylate copolymerized with butyl acrylate or ethyl acrylate. AcryHc latex emulsions are not commonly used in interior flat paints because these paints typicaHy do not require the kind of performance characteristics that acryHcs offer. However, for interior semigloss or gloss paints, aH-acryHc polymers and acryHc copolymers are used almost exclusively due to their exceUent gloss potential, adhesion characteristics, as weU as block and print resistance. 

So-called pure acryUc latexes are employed for maximum durabiUty as required, for example, in high performance exterior latex paints. On the other hand, interior flat wall latex paints do not need the high resistance to exterior exposure and hydrolysis. The most widely used latexes for this appHcation are vinyl acetate copolymer latexes such as vinyl acetate/butyl acrylate (2-propenoic acid butyl ester) [141-32-2] copolymers having just sufficient... 

Branched vinyl esters are strongly resistant to saponification, water absorption and UV degradation. Combining them with VAc and/or acrylate esters affords copolymers with improved water and alkali resistance, and exterior durability. Typically, about 15-30% VV-10 is used to optimize the cost-performance properties of such polymers. Intericn- latexes tend to contain 15-20% monomer. Exterior latexes usually contain 20-30% of the branched monomer. 

Sealants and caulks based on vinyl acetate homo- and copolymers have been on the market since the late 1950s. Use of these lower-performance materials has been mostly in residential areas—bathtub caulking, wall tile joints, wallboard joints, etc. Latex caulks based on polyvinyl acetate plasticized with dibutyl phthalate, or on one of the newer vinyl acetate-acrylic emulsion copolymers, have the same ease of application as the acrylic emulsion caulks but are less flexible, harden on aging, and have inferior exterior durability. ... 

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