Coatings chlorofluorocarbons

The halogenated hydrocarbons known as chlorofluorocarbons are a second class of materials that comprise water-repellent coatings. In particular, the substance known as l,l,2-trichloro-l,2,2-trifluoroethane or CFC-113 (Fig. 7.5.2) is... 

Recent developments in coating technology have enabled cross-linked styrene divinylbenzene porous copolymers to be successfully immobilised on the silica wall of a capillary column. These PLOT columns have similar retention properties to the packed column equivalents but with higher resolution. PoraPLOT columns with Porapak Q, S or U stationary phases are general purpose columns suitable for the analysis of C) -C4 hydrocarbons, chlorofluorocarbons and atmospheric pollutants [35,36]. 

CAAA-90, Title VI (Stratospheric Ozone Protection), will not affect coatings much because chlorofluorocarbons are not used. One interesting case is 1,1,1-trichloroethane (TCE). Since TCE is VOC exempt, its use in coatings increased significantly in the late 1970s. Later it was fonnd that TCE contributes to stratospheric ozone depletion, and therefore it is on the HAPs list. Title VI provides staged phase out of TCE use as a solvent. 

Reduction in the volatile organic content (VOC) of coatings, contributed by the solvents present, is now required because solvents, principally hydrocarbons, contribute through a reaction chain to an increase in ground level pollution (photochemical ozone). The hole in the ozone layer in the stratosphere concerns chlorofluorocarbons (CFC) and is a very different issue. Also of concern to formulators is the removal of lead, chromium and cadmium, which are long term environmental pollutants in paint residues. 

Uses Oil/grease/water resist, aid for paper and paperboards used in packaging for the Food Service and Quick Service Restaurant market Features Effectively applied either in wet end, surface (size or film press) and coating do not contain any chlorofluorocarbons not intended tor use in microwave or bakery applies. 

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