Drying time alkyd

Several other resins can be blended with alkyd resins to introduce desired improvement in properties, e. g. cellulose nitrate, chlorinated rubber, phenolics, amino resins or silicons oils. Vinyl monomers like styrene can be added to alkyd resins along with initiator to get a tougher resin with shorter drying times and lighter colour. 

Fig. 80 Influence of the gloss of air-dried alkyd resin systems containing Pigment Red 3 of different particle sizes with the drying time. Pigment content of the systems 8%.

Fig. 81 Scanning electron micrographs of long-oil alkyd resin systems containing P.R.3, (a) nonhazing, (b) hazing. Drying time 1 day.

Fig.12. Comparison between a conventional high solid alkyd coating ( ) and an alkyd based on a hyperbranched aliphatic polyester ( ). Drying time as a function of molar mass [123]...

Pettersson and Sorensen have described a number of different thermoset resin structures based on hyperbranched aliphatic polyesters [123]. Their results can best be exemplified by a study on hyperbranched alkyd coating resins. A comparative study was performed between an alkyd resin based on a hyperbranched aliphatic polyester and a conventional high solid alkyd, which is a less branched structure. The hyperbranched resin had a substantially lower viscosity than the conventional resin of comparable molecular weight, that is, less solvent was needed to obtain a suitable application viscosity. The hyperbranched resin also exhibited much shorter drying times than the conventional resin, although the oil content was similar. These achievements would not have been possible without a change in architecture of the backbone structure of the resins (Figs. 12,13). 

The presence of conjugated unsaturation up to a limit of about one-half of the total unsaturation has a beneficial effect on the drying time. However, the ultimate hardness of the alkyd film is not appreciably affected. 

On account of these disadvantages and the relatively long drying time, oil paints have almost completely lost their former importance over the last 30 years in favor of oxidatively drying alkyd resins. Being naturally-based paints , renewed interest has, however, recently been shown in oil paints owing to ecological reasons. 

Nitropropane [ 79-46-9] is a colorless, nonhygroscopic liquid with a mild odor. It dissolves cellulose nitrate, cellulose ethers, alkyd resins, chlorinated rubber, poly(vinyl acetate), vinyl chloride copolymers. Poly(vinyl chloride), colophony, polyacrylonitrile, waxes, rubber, and shellac are insoluble. It is used as a cosolvent in paints to improve pigment wetting, flow properties, and electrostatic processing it also reduces the paint drying time. 2-Nitropropane is classified as carcinogenic. 

They have exceUent adhesion properties and can be used to protect against mild chemical fumes. These coatings polymerize by air oxidation at room temperature. Coatings based on alkyd resins synthesized from soybean oils possess better chemical resistance and drying times. 

As with almost all other resin classes, work has been done to make alkyd resins for coatings that can be reduced with water. One approach that has been more extensively studied in Europe than in the United States is the use of alkyd emulsions (25,26). The emulsions are stabilized with surfactants and can be prepared with little, if any, volatile solvent. Some problems limit use of alkyd emulsions (27). Coatings prepared using alkyd emulsion loose dry time on storage because of absorption of cobalt drier on the surface of pigments and precipitation of cobalt hydroxide. Best results were obtained with a combination of cobalt neodecanoate... 

Fig. 14. Hyperbranched resins have much shorter drying times than conventional resins (alkyd resin made from Boltorn). Reference alkyds and -B- dendritic alkyds.

Percent Alkyd Oil Tensile Strength, KG/CM Percent Elongation Dry Time, Hours... 

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