Phthalic other products

The glyptals made from phthalic anhydride and glycerol were developed as compositions for use in paints and varnishes. If the reaction was carried out too long the product became intractible. But under milder conditions, other products could be obtained which could be used in making soluble products and then they could be set further after forming. It was learned that by modifying the reaction mixture with some monobasic acid to balance the hydroxyls and carboxyls in the reaction mixture, more soluble products could be obtained. Kienle of General Electric, was one of the early developers of these products. Later many other alkyd resins from other polyhydroxyl compounds and poly acids were produced for technical use. 

Naphthalene. Until the 1960s, the principal oudet for naphthalene was the production of phthalic anhydride however, more recendy, 0-xylene has replaced naphthalene as the preferred feedstock (see Phthalic acids). Nevertheless, of the 201,000 t produced in 1994 in japan, 73.2% was used for phthalic anhydride production. The rest was consumed in dye stuffs manufacture and a wide variety of other uses. Naphthalene is also used to produce phthalic anhydride in the United Kingdom, Belgium, and the Czech Republic, and can be used by Koppers in the United States in time of 0-xylene shortages. In Europe, the traditional uses for naphthalene have been for the manufacture of p-naphthol and for dye stuff intermediates (see Dyes AND DYE intermediates). ... 

Since some of the naphthalene is oxidized to other products, only 70% of the maximum yield predicted by the above equation is actually obtained. How much phthalic anhydride would be produced in practice by the oxidation of 100 lb... 

About one-half of the phthalic anhydride production is consumed for the preparation of plasticizers, mostly for the various flexible grades of poly(vinyl chloride). The remainder is roughly split between alkyd resin preparation used for many types of surface coatings, and for polyester resin composites with fiberglass reinforcement, the so-called fiberglass resins used in boats and other sporting equipment as well as for corrosion-resistant vessels and ducts used in chemical processing, some automotive parts, and as a convenient means of field repair of many of these items. 

To obtain the total yield in relation to e-xylene, it is necessary to consider that of the phthalic anhydride production step, which barely exceeds 65 to 70 molar per cent in the gas phase oxidation (Von Heyden type reactor). At present no industrial plant employs this process, which is uneconomical in comparison with other methods, given the lack of selectivity of the o-xylene conversion step. 

Esters of 1,2-benzenedicarboxylic acid (phthalic acid esters, PAEs, phthalates) comprise a group of organic compounds used in large quantities by present day society (Fig. 5). The worldwide production of PAEs was estimated to be 4.2x 10 kg during 1994 [125]. PAEs are mainly used as plasticizers in polyvinyl chloride (PVC) plastics and may constitute up to 67% of their total weight. They are also used in a variety of other products such as cosmetics, ammunition, and inks [126]. 

You have recendy joined the TBWS Chemical Corporatiom One of TBWS s major businesses has always been production of phthalic anhydride from naphthalene. Phthalic anhydride production is integrated as part of a large chemical plant, in which naphthalene is produced and in which phthalic anhydride is immediately used to make polyester resins. In recent years, there have been some problems. Some end users have complained about the quality of the resins produced and have taken their business to other companies that produce phthalic anhydride from o-xylene. Therefore, our plant, which had been designed to produce 100,000 metric tons/year of phthalic anhydride from naphthalene, was scaled back to about 80,000 metric tons/year several years ago. We are now forced to scale down production once again due to the loss of another large customer. Marketing informs us that we may lose additional customers. 

Used as fibres, particularly in textiles and film. Many other polyester polymers are of importance, e.g. unsaturated polyester resins from phthalic anhydride, propylene glycol and maleic anhydride used with reinforcement in boats, cars, etc. (alkyd resins). U.S. production 1983 1-7 megatonnes. 

Until the mid-1950s the main raw material source for the European plastics industry was coal. On destructive distillation coal yields four products coal tar, coke, coal gas and ammonia. Coal tar was an important source of aromatic chemicals such as benzene, toluene, phenol, naphthalene and related products. From these materials other chemicals such as adipic acid, hexamethylenedia-mine, caprolactam and phthalic anhydride could be produced, leading to such important plastics as the phenolic resins, polystyrene and the nylons. 

Phthalic anhydride, a polyol, and an unsaturated fatty acid are usually copolymerized to unsaturated polyesters for coating purposes. Many other combinations in variable ratios are possible for preparing these resins. The 1998 U.S. production of polyesters was approximately 1.7 billion pounds. 

The flexibility of some plastics can be improved by the addition of small molecules called plasticizers. For example, pure PVC turns brittle and cracks too easily to make useful flexible plastic products. With an added plasticizer, however, PVC can be used to make seat covers for automobiles, raincoats, garden hoses, and other flexible plastic objects. Plasticizers must be liquids that mix readily with the pol Tner. In addition, they must have low volatility so that they do not escape rapidly from the plastic. Dioctylphthalate is a liquid plasticizer that is formed by condensing two alcohol molecules with one molecule of phthalic acid, as illustrated in Figure 13-10. 

The transformation and metabolism products of pesticides in plants may not only be of acute toxicity, but also may have other properties. Phosmet, for example, transforms into phthalimide and phthalic acid, teratogenic substances [21]. 

This chapter contains a discussion of two intermediate level problems in chemical reactor design that indicate how the principles developed in previous chapters are applied in making preliminary design calculations for industrial scale units. The problems considered are the thermal cracking of propane in a tubular reactor and the production of phthalic anhydride in a fixed bed catalytic reactor. Space limitations preclude detailed case studies of these problems. In such studies one would systematically vary all relevant process parameters to arrive at an optimum reactor design. However, sufficient detail is provided within the illustrative problems to indicate the basic principles involved and to make it easy to extend the analysis to studies of other process variables. The conditions employed in these problems are not necessarily those used in current industrial practice, since the data are based on literature values that date back some years. 

As pointed out previously, controlled degradation reactions are very difficult with aliphatic or alicyclic hydrocarbons, and most of the relabeling work has been concentrated on aromatic reaction products. Procedures have been extensively described by Pines and co-workers (e.g., 97, 96, also 87, 89-98, 95, 98). For the present purpose, it suffices to note that the 14C contents of the methyl side-chains and the rings in aromatic reaction products are readily estimated by oxidation of the methyl to carboxyl, followed by decarboxylation, while ethyl side-chains may be oxidatively degraded one carbon atom at a time. Radiochemical assays may be made on CO2 either directly in a gas counter, or after conversion to barium carbonate, while other solid degradation intermediates (e.g., benzoic acid or the phthalic acids) may be either assayed directly as solids or burned to CO2. Liquids are best assayed after burning to CO2. 

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