Isophorone manufacture

According to the most recent edition of the United States International Trade Commission publication on U.S. production and sales of synthetic organic chemicals (USITC 1987), Union Carbide (Institute, WV), is the only domestic manufacturer of isophorone. A comparison of the list of isophorone manufacturers in USITC (1987) and USITC (1986) shows that Exxon Corporation (Bayway, NJ) also manufactured this chemical, but discontinued production in 1985. Because of the limited number of domestic manufacturers of isophorone and their desire to maintain confidentiality, up-to-date information regarding the production volume of isophorone in the U.S. is not available. In 1973, 35 million pounds of isophorone were produced in the United States (Papa and Sherman 1981) and in 1980, approximately 20-30 million pounds were produced (CMA 1981). The decrease may be because of replacement of isophorone with less costly solvents (CMA 1981). 

Little data are available to estimate releases of isophorone to water. During isophorone manufacture, process water may contact the isophorone and carry some of it to wastewater streams. During use of isophorone, paint spray booths that use water curtains, wash water, and process water all may contain isophorone. Isophorone has been detected in the United States in industrial effluent... 

For environmental reasons there has been interest in methods for manufacturing isocyanates without the use of phosgene. One approach has been to produee diurethanes from diamines and then to thermal eleave the diurethanes into diisocyanates and alcohols. Although this method has been used for the production of aliphatic diisocyanates such as hexamethylene diisocyanate and isophorone diisocyanate, for economic reasons it has not been adopted for the major aromatic isocyanates MDI and TDI. 

Isophorone has a water solubility of 12,000 ppm, a log octanol/water partition coefficient of 1.67, a Henry s Law constant of 4.55 X 10 atm m mof, a vapor pressure of 0.3 mm Hg at 20 C, a log sediment sorption coefficient of approximately 1.46, and a log bioconcentration factor (BCF) of 0.85. Isophorone is released to air and water from its manufacturing and use. Based on its water solubility, some isophorone may wash out of the atmosphere however, only limited amounts will be washed out because of the short atmospheric half-life of isophorone. Particularly during the day, when hydroxyl radical (HO) concentrations are highest, very little atmospheric transport will occur due to its fast reaction with HO. ... 

Populations with potentially high exposure include those occupationally exposed to isophorone (e.g., screen print workers, some adhesives formulators and users, some coatings manufacturing and use workers). Individuals living near hazardous waste sites may be exposed to isophorone dermally, but probably not by inhalation. These individuals also may be exposed to isophorone by ingestion if they drink water from contaminated wells located down gradient from the site. 

CMA. 1984. Voluntary Testing Program under Section 4 of the Toxic Substances Control Act. Submission of Test Data. Volume III. Isophorone Mutagenicity Studies. Unpublished studies performed by Microbiological Associates, Bethesda, MD for Chemical Manufacturers Association, Washington, DC. OTS Section 4 submission. Doc. ID. 40-8455047. Microfiche No. OTS0507222. 

Manufacture. Isophorone is produced by aldol condensation of acetone under alkaline conditions. Severe reaction conditions are required to effect the condensation and partial dehydration of three molecules of acetone, and consequendy raw material inefficiency to by-products is limited by employing low conversions. Both liquid- and vapor-phase continuous technologies are practiced (186,193,194). 

The technology has been commercialized, in collaboration with the Thomas Swan company, for the manufacture of trimethyl cyclohexanone by Pd-catalyzed hydrogenation of isophorone (Fig. 7.22) [77]. 

Isolation of pure m-cresol from a mixture of m-, p-, cresols soon became a reality and commercially viable during manufacture of BHT from a mixture of m-, p-, cresols through the process of butylation, and dealkylation of butylated m-cresol. A number of companies are now producing BHT from mixed cresols and obtaining pure m-cresol as a co-product. m-Cresol is also commercially produced from isophorone. 

Poliakoff and co-workers developed a catalytic hydrogenation process which has been commercialized by Thomas Swan and Co. for the manufacture of trimethylcy-clohexanone by Pd-catalyzed hydrogenation of isophorone (Equation 4.29) [52],... 

Metaxylenol is an important intermediate for the manufacture of para chloro meta xylenol which is used a disinfectant. Meta xylenol may be produced by liquid phase or by vapour phase reaction. Metaxylenol is produced by sulphonation of xylene followed by hydrolysis in liquid phase but this yeilds many other by-products(l,2,3). However, catalytic conversion of isophorone yields meta xylenol selectively and the amounts of other by-products can be controlled (4,5,6). 

Aldolization is widely used in organic synthesis for C-C bonds creation. It is commonly u.sed U) manufacture solvents (diaceionc alcohol, isophorone), iniemiediaies for the manufacture of perfumes and phannnceuticals (chalconcs and more generally a. -unsaturated ketones) and plaslici/crs [ 184]. 

Isophorone is a stable, colorless, volatile liquid with a mild odor. It is only slightly soluble in water, but miscible with most lacquer solvents. It is an excellent solvent for many types of cellulose esters, cellulose ethers, oils, fats, gums and resins, both natural and synthetic. It is the most powerful solvent for nitrocellulose and "Vinylite" resins. Isophorone has one of the highest oromatic hydrocarbon dilution ratios for nitrocellulose—5.7 for toluene ond 5.1 for xylene, it will dissolve 30% of "Vinyllte" resin without gelling. At ordinary temperatures solutions can be made of second RS nitrocellulose containing 45% solids. Isophorone is used in the manufacture of coatings, inks, stencil pastes and as a thinner in synthetic resin finishes. 

The U.S. and European production figures for acetone are approximately M and 0-5 Mt per annum respectively. The largest single chemical use (approx. 30%) is in methyl methacrylate manufacture. Of the aldol derivatives, methyl isobutyl ketone (MIBK) (4-methylpentan-2-one) takes some 10-15%, but several others, such as diacetone alcohol and isophorone, have individual sales of 10 to 25 kt per annum (for brake fluids, speciality solvents, etc.). 

Only the diisocyanates are of interest for urethane polymer manufacture and relatively few of these are employed commercially. The most important ones used in elastomer manufacture are the 2,4- and 2,6-toluene diisocyanates (TDl) 4,4 -diphenylmethane diisocyanates (MDI) and its aliphatic analogue 4,4 -dicyclohexylmethane diisocyanate (Hi2 MDI) 1,5-naphthalene diisocyanate (NDI) 1,6-hexamethylenediisocyanate (HDI) xylyene diisocyanate (XDI), isophorone diisocyanate (IPDI) and 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (TMDI). Also manufactured commercially are various monoisocyanates, including methyl, /7-propyl, /7-butyl, cyclohexyl, phenyl, and 4-chloro- and 3,4-dichlorophenyl isocyanates which are used for substituted ureas and carbamates important as herbicides and crop protection agents. 

Isophorone diisocyanate (IPDI) has traditionally been manufactured from isophorone diamine (IPDA) by the conventional phosgenation route as shown below ... 

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