Alkyd resins processing

Fig. 1 Alkyd resin processing equipment. [Reprinted from Amoco TMA as Primers for Alkyd-Melamine Enamels and Acrylic Lacquers, Tec. Bull. TMA 25a. Amoco Chemical Corp., Chicago, Illinois, 1974.]...

Processes have been developed separating pure metaxylene from other Cj aromatics.Metaxylene is a raw material for the manufacture of isophthalic acid. The major outlets for the acid are in the synthesis of unsaturated polyester and alkyd resins, and for the production of isophthalic esters (plasticizers). 

Polyester-based networks are typically prepared from polyester prepolymers bearing unsaturations which can be crosslinked. The crosslinking process is either an autoxidation in the presence of air oxygen (alkyd resins) or a copolymerization with unsaturated comonomers in the presence of radical initiators (unsaturated polyester resins). It should also be mentioned that hydroxy-terminated saturated polyesters are one of the basis prepolymers used in polyurethane network preparation (see Chapter 5). 

Another commercially important crosslinking process that involves unsaturated polymer precursors is the so-called drying of alkyd resins in paints. This process is not drying at all, at least not in the sense of mere loss of solvent to leave behind a solid residue. Instead, the main process is the conversion of high relative molar mass molecules to a crosslinked structure via... 

Non-drying oil resins are soluble only in Aromatic hydrocarbons. They are used with amino resins for stoving finishes for appliances. Medium resins are used as plasticisers for cellulose nitrate. Along with natural oils several natural occurring and synthetic acid like resin (abiotic acid) pelargonic acid and isooctanoic acid are added to modify alkye resins. The alkyd resins are obtained by two processes, i.e., (1) Fatty Acid Process and (2) Alcoholysis process. 

The main ingredients for the early alkyd resins, namely phthalic anhydride and glycerol, were already quite readily available at the time of their development. At that time, phthalic anhydride was made by catalytic oxidation of naphthalene with sulphuric acid. However, a considerable boost to the competitiveness of alkyds was the development from about 1917 of a much cheaper process for phthalic anhydride, based on catalytic vapour-phase oxidation of naphthalene. 

Isophthalic acid is made by the same process as TPA, liquid phase air oxidation. Yields are about 80%. Isophthalic does have some unique redeeming value—it will enhance, to some extent, the mechanical and temperature sensitive properties of polyesters, alkyd resins, and glass reinforced plastics. 

Hydrolysis of Chlorinated Hydrocarbons. The production of oxygenated aliphatics by the hydrolysis of chlorinated hydrocarbons includes the synthetic glycerol process and the amyl alcohols process. Glycerol (7) is made from propylene via allyl chloride (CH2 CHCH2C1), and competes with glycerol made from fats and oils for use in dynamite and alkyd resins, as a tobacco humectant and cellophane plasticizer, in cosmetics and pharmaceuticals, and for other applications. Amyl alcohols have been made since 1926 by the alkali hydrolysis of a mixture of amyl chlorides, made by the chlorination of pentanes from natural gasoline. Production from this source far exceeds the supply from the fusel oil by-product of fermentation processes. Amyl alcohol and its derivatives are used mainly as solvents. 

An aromatic compound which is employed along with glycerol in the production of alkyd resins is phthalic anhydride. The conventional process for the manufacture of this chemical has been from the catalytic oxidation of coal tar naphthalene, and annual production of the anhydride in recent years has been around 150,000,000 pounds. In 1946 production was started (4) in a plant of the Oronite Chemical Co. at Richmond, Calif., to produce phthalic anhydride by the oxidation of o-xylene produced in a hydroformer unit of the adjacent Standard Oil Co. of California refinery. The Oronite plant was reported to have a design capacity of 7,000,000 to 8,000,000 pounds per year of 99.7% pure phthalic anhydride. 

Fusion process - [ALKYD RESINS] (Vol 2) - [ALKYD RESINS] (Vol 2) -for glasses [GLASS] (Vol 12) -metal soap mfg [DRIERS AND METALLIC SOAPS] (Vol 8)... 

Palmitic acid [57-10-3] - [ALKYD RESINS] (Vol 2) - [TALL OIL] (Vol 23) - [CASTOR OIL] (Vol 5) - [CARBOXYLICACIDS-SURVEY] (Vol 5) -in drying oils [DRYING OILS] (Vol 8) -in fats and oils [CARBOXYLIC ACIDS - ECONOMIC ASPECTS] (Vol 5) -in fats and oils [CARBOXYLIC ACIDS - MANUFACTURE] (Vol 5) -as release agent [RELEASE AGENTS] (Vol 21) -separation coefficients for [SEPARATIONS PROCESS SYNTHESIS] (Vol 21)... 

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