Continuing development of low VOC benzoate coalescents: high PVC interior grade, primer, direct to metal coatingd

 
Blends of dibenzoate esters have been developed to assist formulating low VOC paint for the ever more restrictive regulations on paint VOC content. Dibenzoate blends were found to significantly reduce VOCs and they are effective coalescents in interior and exterior architectural coatings. There was no significant loss in any performance parameters with gains in scrub (physical) and gloss compared to coalescents such as 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate (TMPDMIB). These blends are 1) diethylene glycol dibenzoate blend with dipropylene glycol dibenzoate designated 850S, and 2) diethylene glycol dibenzoate blend with dipropylene glycol dibenzoate and propylene glycol designated 975P. The need for ISO 16000-6 VOC data on the dibenzoates was apparent, so this test was run in an EU flat paint. The ISO data as well as performance data are presented. Traditionally, low VOC coalescents (plasticizers) have been used in applications such as light industrial waterborne coatings because of the use of hard (high Tg) polymers; phthalates have been recommended for such applications and glycol ethers have also fit in that coatings market segment. Based on the need for a true plasticizer, the two dibenzoate blends were tested. The results of this work will be discussed.