Methylene Chloride

Brief Overview

Methyl salicylate (wintergreen oil) is an organic ester produced naturally by many plant species, mainly wintergreens. Methyl salicylate was first extracted and isolated from Gaultheria procumbens. It is also synthetically produced to be used in in foods and beverages, used as fragrance and in liniments. It is colorless to yellow or reddish liquid and it exhibits a characteristic odor and taste of wintergreen. Methyl salicylate is used as rubefacient and analgesic in deep heating liniments for acute joint and muscular pain. It is also used as a flavoring agent in chewing gums and mints in small concentrations and added as antiseptic in mouthwash solutions.

Manufacturing Process

Methyl Salicylate is industrially produced using a process called the Kolbe-Schmitt reaction. First, phenol is reacted with sodium hydroxyde (NaOH) and carbon dioxide (CO₂) to add the carboxylic acid group to the molecule to obtain salicylic acid. Salicylic acid is then methylated to obtain methyl salicylate. A byproduct, double carboxylation of phenol, is formed in minute quantities during the Kolbe-Schmitt process.

Food and Beverage Industry

Methylene chloride is commonly used as an extraction solvent in the food and beverage manufacturing industry. For instance, methylene chloride can be used to remove caffeine or decaffeinate unroasted coffee beans and tea leaves. Methylene chloride is also used in processing spices, creating hops extract for beer and other flavorings for the food and beverage industries.

Transportation Industry

Methylene chloride can be used to degrease metal surfaces and parts, such as airplane components and railroad tracks and equipment. Lubricating and degreasing products used in automotive products, like in gasket removal and for prepping metal parts for a new gasket, could possibly contain methylene chloride. Automotive specialists uses methylene chloride vapor degreasing process to remove oils and grease from car transistor parts, diesel motors and aircraft components and spacecraft assemblies. Modern vapor degreasing techniques that utilizes methylene chloride allows metal parts in transportation systems to be cleaned quickly and safely.

Medical Industry

In laboratories, methylene chloride is used to extract chemicals such as steroids, antibiotics and vitamins from plants or foods for medicinal use. Medical equipment can be cleaned efficiently and rapidly with methylene chloride cleaners without causing corrosion problems or damage to heat-sensitive parts.

Other Applications

Methylene chloride is used in the production of photographic films, synthetic fibers, adhesives, inks and printed circuit boards.