Finishing/converting

Flavanthrone, like indanthrone, must be extremely pure in order to develop useful pigment properties. Subsequent finishing converts the thus prepared material into an appropriate product for use in paints or plastics. 

The design of the synthesis foi 1 is now finished. The target eompound (1) can be simplified to eommeicially available starting materials which can easily be converted to the target compound in the synthesis direction, Figure 10.3-56 shows the entire synthesis tree interactively developed with the WODCA program. 

More and more raw spices are converted to finished products near the growing sites. This saves shipping costs of bulk vs concentrate. Rapid processing also assures less loss of flavor volatiles resulting from evaporation, reduction of colored components due to oxidation or isomeri2ation, and reduction of losses due to insect and rodent infestation. 

Often used as mixtures, the telomers are subsequently converted to commercial surfactants and stain-resistant fiber finishes through functionalizing steps using standard chemical reactions of the C—1 bond. 

Food processing firms producing heat-preserved, frozen, dehydrated, or chemically preserved foods may be classified by their finished products. Companies may be further grouped based on whether they process raw materials into ingredients, such as in poultry and meat processing plants, or whether they take these ingredients and convert them to ready-to-eat consumer products. 

The 2eohtes are prepared as essentially bindedess preformed particles. The kaolin is shaped in the desired form of the finished product and is converted in situ in the pellet by treatment with suitable alkaU hydroxide solutions. Preformed pellets of 2eohte A are prepared by this method. These pellets may be converted by ion exchange to other forms such as molecular sieve Type 5A (1). ZeoHtes of higher Si02/Al202 ratios, eg, 2eohte Y, can be obtained by the same method, when sodium metasiUcate is incorporated in the preshaped pellets, or when acid-leached metakaolin is used. 

Olig omerization and Polymerization. Siace an aHyl radical is stable, linear a-olefins are not readily polymerized by free-radical processes such as those employed ia the polymerization of styrene. However, ia the presence of Ziegler-Natta catalysts, these a-olefins can be smoothly converted to copolymers of various descriptions. Addition of higher olefins during polymerization of ethylene is commonly practiced to yield finished polymers with improved physical characteristics. 

The second process to finish phthalocyanine, which is more important for P-copper phthalocyanine, involves grinding the dry or aqueous form in a ball mill or a kneader (64). Agents such as sodium chloride, which have to be removed by boiling with water after the grinding, are used. Solvents like aromatic hydrocarbons, xylene, nitrobenzene or chlorobenzene, alcohols, ketones, or esters can be used (1). In the absence of a solvent, the cmde P-phthalocyanine is converted to the a-form (57,65) and has to be treated with a solvent to regain the P-modification. The aggregate stmcture also has an impact on the dispersion behavior of a- and P-copper phthalocyanine pigments (66). 

Nylon is the preferred fiber for flocking because of its good chemical bonding to a wide range of adhesives, its toughness, and its ease of dyeabiHty and printabihty. Nevertheless, the tow must be manufactured with the proper ktex, cohesion, and spin finish to be readily converted to flock (133). 

Sulfur is unusual compared to most large mineral commodities in that the largest portion of sulfur is used as a chemical reagent rather than as a component of a finished product. Its predominant use as a process chemical generally requires that it first be converted to an intermediate chemical product prior to use in industry. In most of the ensuing chemical reactions between these sulfur-containing intermediate products and other minerals and chemicals, the sulfur values are not retained. Rather, the sulfur values are most often discarded as a component of the waste product. 

Liquid mixtures of methanol and hydrochloric acid slowly yield methyl chloride even at 0°C (20,21), The typical process is carried out by contacting the alcohol with hydrochloric acid at 70 to 160°C and 0.1—1 MPa (15—150 psig) in the presence of a catalyst such as zinc chloride, quaternary amines (18,19,22), or with no catalyst at aH (23,24). TypicaHy 0.5 to 3% of the methanol is converted to dimethyl ether. Product methyl chloride is taken out of the reactor as a vapor and is cooled to condense as much of the water vapor and HCl as possible. Dimethyl ether and the residual water is then removed and the finished methyl chloride is condensed. 

Nylon resins are made by numerous methods (53) ranging from ester amidation (54) to the Schotten-Baumann synthesis (55). The most commonly used method for making nylon-6,6 and related resins is the heat-induced condensation of monomeric salt complexes (56). In this process, stoichiometric amounts of diacid and diamine react in water to form salts. Water is removed and further heating converts the carboxylate functions to amide linkages. Chain lengths are controlled by small amounts of monofunctional reagents. The molten finished nylon resin can be dkectly extmded to pellets. 

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