الوصف

Cresols are methyl substituted phenols at relative to the hydroxyl group, ortho-, meta-, and para-cresol. There are three structural isomers. The names of the three compounds indicate which of the hydrogens on the benzene ring portion of the molecule have been replaced. They are obtained from coal tar or petroleum as by-products in the fractional distillation and in coal gasification. They are also formed as by-products during the combustion of wood. The various isomers can be manufactured by the methylation of phenol, toluene sulfonation and alkaline hydrolysis, or the hydrolysis of *-isopropyltoluene or alkaline chlorotoluene. Because the boiling points of these three compounds are nearly the same, a separation of a mixture of the three into its pure components is impractical. They are highly flammable and soluble in water, ethanol, ether, acetone and alkali hydroxides. The mixture of cresols obtained from coal tar is called cresylic acid, an important technical product used as a disinfectant and in the manufacture of resins and tricresyl phosphate. Cresylic acid also refs to the mixture of phenols containing varying amounts of xylenols, cresols, and other high-boiling fractions, but not more than 5 percent phenol. Commercial cresols are prepared in a wide range of grades and purities to meet the user's requirements.  It is a liquid from clear to brown and is toxic to animals including human. It is corrosive and is a more powerful disinfectant and antiseptic than phenol. The primary use is for sterilizing as disinfectants and deodorizers, and pesticides. Its solution is used as household cleaners as a disinfectant. Creosote products are mixtures of many aromatic hydrocarbons including phenols and cresols. Creosote obtained from coal tar is poisonous and provides protection against fungi, shipworms, termites, and psoriasis. It is used chiefly as a wood preservative, e.g., in wooden poles, railroad ties, and timber. They are also used as animal and bird repellents. Animals may suffer skin irritation or ulceration from creosote treated wood. Coal tar creosote and its derivatives are the most widely used wood preservatives. Wood tar creosote is a mixture of chiefly guaiacol, creosols and other phenolic compounds obtained from wood tar (mainly beech) by distillation between **3 and **0 C. It is insoluble in water, soluble in methanol, acetone. It is used as an external antiseptic, expectorant, gastric sedative, deodorant, and as an antiseptic parasiticide veterinary use in the form of creosote carbonate. It is used in the synthesis of pharmaceuticals and vanillin. Each cresols are used as solvents or disinfectants and as useful as raw materials for various chemical products including;

• Antiseptics, disinfectants
• Fragrances, deodorizing, odor-enhancer
• Resins (phenol-formaldehyde, phenolic, and epoxy) and their additives
• Phosphate esters (plasticizers)
• Herbicides and pharmaceuticals
• Rubber and plastic antioxidants
• Dyes and pigments
• Household cleaners and automotive degreasers
• Solvent and paints
• Lubricating oils, gasoline additives
• Adhesives
• Fiber and wood preservatives
• UV-absorbers andphotographic chemicals
• Ore flotation agents