Alkyd resins polybasic acid component

If the total alkyds consumed in recent years is classified by their dibasic acid component, about 50% belongs to the unmodified phthaHc type, about 28% modified phthaHc type, about 13% based on isophthaHc, and the balance based on polybasic acids other than phthaHc or isophthaHc. The top alkyd resin manufacturers in the U.S. are Cargill, Reichhold, a subsidiary of Dainippon Ink Chemicals, Inc., and Spencer KeUog, now a part of NL Industries, Inc. The median price (52,53), of general types of alkyd resin, soHds base, was 1.98/kg in Nov. 1990 compared to about 440 in 1955, about 660 in 1975, and about 1.54 in 1983, reflecting the increases in raw material cost. 

Each of the three principal components of alkyd resins—the polybasic acids, the polyols, and the monobasic acids— has a large variety to be chosen from. The selection of each one of these ingredients will affect the properties of the resin. As will be shown later, the choice of ingredients may even affect the choice of manufacturing processes. To both the resin manufacturers and the users, the selection of the proper ingredients is a major decision. 

The detection and identification of polar components is also possible using simultaneous hydrolysis and alkylation. These are normally difficult or impossible to determine because they tend to remain on the column, cause peak tailing, show poor reproducibility, or lose their identity due to the formation of low molecular weight fragments. Thus, for example, methyl esters of polybasic acids and long-chain fatty acids and methyl ethers of polyhydric alcohols are formed from alkyd resins with TMAH, whereas in conventional PyGC, aldehydes are formed from polyols, and alkanes and alkenes from fatty acids (Figure 6). 

The term rosin-based alkyd resins refers to alkyd resins in which all or a portion of the monobasic fatty acid is replaced by rosin (a mixture of diterpene resin acids and nonacidic components). Unmodified alkyd resins are polyester products composed of polyhydric alcohol, polybasic acid, and monobasic fatty acid. 

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