GB923857A - Preparation of oil-modified alkyd resins - Google Patents

Abstract

Oil-modified alkyds having an acid number below 25 and based on isophthalic or tereph thalic acid or their substitution products (e.g. 5-tertiary butyl isophthalic or 2-methyl tereph thalic acid) are obtained by an acidolysis process. The process for making the alkyd comprises (a) heating a mixture of the dicarboxylic acid and a triglyceride oil to 500 DEG -535 DEG F., adding a polyhydric alcohol to the mixture whilst maintaining the temperature at 500 DEG F.-535 DEG F., and thereafter effecting esterification at an elevated temperature; or (b) heating a mixture of the dicarboxylic acid and a triglyceride oil to produce an acidolysis product with an acid number of at least 100 and thereafter adding a polyhydric alcohol (preferably at below 500 DEG F.) to the mixture and heating to effect esterification; or (c) heating a mixture of the dicarboxylic acid, a triglyceride oil and a fatty acid to initiate acidolysis of the oil and thereafter adding a polyhydric alcohol to the mixture and heating to effect esterification. The polyhydric alcohol may be glycerol which may be replaced wholly or in part with ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, trimethylol propane, pentaerythritol, dipentaerythrital, mannitol or sorbitol. The triglyceride oil may be safflower, soya, linseed, castor, corn, coconut, cottonseed, oiticica, perilla, rapeseed, poppyseed, sunflower, tall, tung, herring, menhaden or sardine oil. The fatty acid may be one derived from the above oil, e.g. caproic, caprylic, capric, lauric, myristic, palmitic, stearic, arachidic, behinic, oleic, ricinoleic, tall, linoleic, linolenic or licanic acid. Examples describe the preparation of resins from isophthalic or terephthalic acid, glycerol, and one of the oils mentioned above or a mixture of linseed or safflower oil and tall oil fatty acids.