Caprolactam CAS

National Institutes of Health (1982a). Carcinogenesis bioassay of caprolactam (CAS No. 105-60-2) in F334jN rats andB6C3F] mice (feedstudy). NTP Technical Report Series No. 212, NIH Publ. No. 81-1770, Research Triangle Park, NC and Bethesda, MD. 

CAPROLACTAM. [CAS 105-60-2]. NHfCH ),CO. formula weight 112.15. liquid ingredient used in the manufacture of lype 6 nylon. See also Fibers. Several hundred million pounds of ihe compound are produced annually. There are a number of proprietary processes for caproluctam production. 

Caprolactam (CAS 105-60-2) Highly Irritating to eyes and skin upon direct contact. Vapors, dusts, and fumes highly irritating to eyes and respiratory tract. Convulsant activity in test animals. 1 mg/m (dust) 5 ppm (vapor) [proposed 5 mg/m (aerosol and vapor)] White solid crystals. Unpleasant odor. Vapor pressure is 6 mm Hg at 120°C (248°F). Thermal-breakdown products include oxides ot nitrogen. 

Chem. Descrip. N-Vinyl-2-caprolactam CAS 2235-00-9 EINECS/ELINCS 218-787-6 Uses Reactive diluent for free radical radiation-curable coatings, inks, and adhesives for flooring, paper, wood, particle board, plastics, textiles, and vinyl... 

The diamine-terminated nylon 6/66 copolyamide oligomers (CPA, Scheme 6), having the values shown in Table 7 were synthesized by the melt polycondensation reaction of e-caprolactam (CA), adipic acid (AA), and hexamethylene diamine (HA) [37,39]. An excess of HA over AA was used to obtain CPA with terminal amine groups and the molecular weight was controlled by a stoichiometric imbalance of reactants, ie., by varying the AA/HA feed molar ratio at a fixed CA/AA feed molar ratio (Table 7). The diamine-terminated nylon 6... 

Essentially all the ammonium sulfate fertilizer used in the United States is by-product material. By-product from the acid scmbbing of coke oven gas is one source. A larger source is as by-product ammonium sulfate solution from the production of caprolactam (qv) and acrylonitrile, (qv) which are synthetic fiber intermediates. A third but lesser source is from the ammoniation of spent sulfuric acid from other processes. In the recovery of by-product crystals from each of these sources, the crystallization usually is carried out in steam-heated sa turator—crystallizers. Characteristically, crystallizer product is of a particle size about 90% finer than 16 mesh (ca 1 mm dia), which is too small for satisfactory dry blending with granular fertilizer materials. Crystals of this size are suitable, however, as a feed material to mixed fertilizer granulation plants, and this is the main fertilizer outlet for by-product ammonium sulfate. 

AH commercial processes for the manufacture of caprolactam ate based on either toluene or benzene, each of which occurs in refinery BTX-extract streams (see BTX processing). Alkylation of benzene with propylene yields cumene (qv), which is a source of phenol and acetone ca 10% of U.S. phenol is converted to caprolactam. Purified benzene can be hydrogenated over platinum catalyst to cyclohexane nearly aH of the latter is used in the manufacture of nylon-6 and nylon-6,6 chemical intermediates. A block diagram of the five main process routes to caprolactam from basic taw materials, eg, hydrogen (which is usuaHy prepared from natural gas) and sulfur, is given in Eigute 2. 

Concentrations are controlled to yield a molten oxime product layer and a saturated (ca 40 wt %) ammonium sulfate solution ca 125% (theoretical) ammonium sulfate or 2.9 kg/kg caprolactam is produced as a result of side reactions in the hydroxylamine synthesis. 

The oxime is converted to caprolactam by Beckmann rearrangement neutralization with ammonia gives ca 1.8 kg ammonium sulfate per kilogram of caprolactam. Purification is by vacuum distillation. A no-sulfate, extraction process has been described, but incineration of the ammonium bisulfate recovers only sulfur values and it is not practiced commercially (14). 

Snia Viscosa. Catalytic air oxidation of toluene gives benzoic acid (qv) in ca 90% yield. The benzoic acid is hydrogenated over a palladium catalyst to cyclohexanecarboxyhc acid [98-89-5]. This is converted directiy to cmde caprolactam by nitrosation with nitrosylsulfuric acid, which is produced by conventional absorption of NO in oleum. Normally, the reaction mass is neutralized with ammonia to form 4 kg ammonium sulfate per kilogram of caprolactam (16). In a no-sulfate version of the process, the reaction mass is diluted with water and is extracted with an alkylphenol solvent. The aqueous phase is decomposed by thermal means for recovery of sulfur dioxide, which is recycled (17). The basic process chemistry is as follows ... 

During this reaction, some caprolactam is also liberated. The reaction is largely completed within the processing time (typically 3-5 min). The increase in intrinsic viscosity of PET can be adjusted by the amount of CBC. In practice, about 0.5 wt% of CBC is typically used. CBC is commercially available under the trade-name ALLINCO (DSM, Geleen, The Netherlands). ALLINCO is one of the most effective chain extender systems available for PET [21, 22], CBC is often used in combination with PBO for an enhanced chain extension effect. Typically, the relative viscosity of PET is increased from 1.6 to 2.0 with a stoichiometric amount of CBC + PBO (ca. 1.2 wt%) in a single-screw extruder at 300 °C. 

Economies of scale of production are a significant advantage, ca. 300,000 ton/ a of lysine are produced with demand growing at 7% per year. In 1982 this was only 40,00C ton/a, and Toray (Japan) was reported to produce 10% of this via DL-df-amino-t-caprolactam. This compound is easily available to Toray. 

The caprolactam prices shown in Table 4 are for large contracts of molten material. Flaked material is sold in bags, either in small lots or for export, and costs ca 0.10/kg more than the molten product. Exports normally have risen during periods of recession in the United States, eg, 1970,1975, 1980, and 1990. 

Homolytic liquid-phase processes are generally well suited to the synthesis of carboxylic acids, viz. acetic, benzoic or terephthalic acids which are resistant to further oxidation. These processes operate at high temperature (150-250°C) and generally use soluble cobalt or manganese salts as the main catalyst components. High conversions and selectivities are usually obtained with methyl-substituted aromatic hydrocarbons such as toluene and xylenes.95,96 The cobalt-catalyzed oxidation of cyclohexane by air to a cyclohexanol-cyclohexanone mixture is a very important industrial process since these products are intermediates in the manufacture of adipic acid (for nylon 6,6) and caprolactam (nylon 6). However, the conversion is limited to ca. 10% in order to prevent consecutive oxidations, with roughly 70% selectivity.97... 

Process Economics Program Report SRI International. Menlo Park, CA, Isocyanates IE, Propylene Oxide 2E, Vinyl Chloride 5D, Terephthalic Acid and Dimethyl Terephthalate 9E, Phenol 22C, Xylene Separation 25C, BTX, Aromatics 30A, o-Xylene 34 A, m-Xylene 25 A, p-Xylene 93-3-4, Ethylbenzene/Styrene 33C, Phthalic Anhydride 34B, Glycerine and Intermediates 58, Aniline and Derivatives 76C, Bisphenol A and Phosgene 81, C1 Chlorinated Hydrocarbons 126, Chlorinated Solvent 48, Chlorofluorocarbon Alternatives 201, Reforming for BTX 129, Aromatics Processes 182 A, Propylene Oxide Derivatives 198, Acetaldehyde 24 A2, 91-1-3, Acetic Acid 37 B, Acetylene 16A, Adipic Acid 3 B, Ammonia 44 A, Caprolactam 7 C, Carbon Disulfide 171 A, Cumene 92-3-4, 22 B, 219, MDA 1 D, Ethanol 53 A, 85-2-4, Ethylene Dichloride/Vinyl Chloride 5 C, Formaldehyde 23 A, Hexamethylenediamine (HMDA) 31 B, Hydrogen Cyanide 76-3-4, Maleic Anhydride 46 C, Methane (Natural Gas) 191, Synthesis Gas 146, 148, 191 A, Methanol 148, 43 B, 93-2-2, Methyl Methacrylate 11 D, Nylon 6-41 B, Nylon 6,6-54 B, Ethylene/Propylene 29 A, Urea 56 A, Vinyl Acetate 15 A. 

As already discussed in Chapter 1, the commercialization, by Sumitomo [GO-64], of a vapor phase Beckmann rearrangement of cyclohexanone oxime to caprolactam over a high-silica MFI (ZSM-5 type) zeolite (Fig. 2.21) is another benchmark in zeolite catalysis. The process, which currently operates on a 90000 tpa scale, replaces a conventional one employing stoichiometric quantities of sulfuric acid and producing ca. 2 kg of ammonium sulfate per kg of caprolactam. 

The first commercial applicahon, made possible by an agreement between EniChem and Sumitomo, went on-stream in 2003 in Japan, within the context of an integrated process for the produchon of e-caprolactam by a new salt-free technology (ca GOOOOta ). Actually, besides the ammoximation step, no major byproduct is produced even in the gas-phase rearrangement carried out on silicalite-1 as the catalyst. On the whole, the ammonium sulfate is no longer a burden and the gaseous emissions too are drashcally reduced. 

Heikens and Hermans [215] further improved the E eement between the experimental and calculated course of caprolactam polymerization by taking into consideration the volume contraction (ca. 9%) occurring during the polymerization. 

In 1996 the worldwide capacity caprolactam capacity was ca. 4400 10 t. Over 90% of plants operate with hydroxylamine as an intermediate. The hydroxylamine capacities are not recorded separately, but in total must be at least 1 10 t/a (calculated on the basis of NH2OH), assuming 100% synthesis yield, in order to provide this caprolactam capacity. 

The hydroxylamine content in this solution, which also contains ammonium sulfate, is ca. 70g/L. In an integrated caprolactam manufacturing plant using the Raschig process for hydroxylamine production, ca. 1.8 kg of ammonium sulfate is produced per kg of caprolactam. 

The quantity of ammonium sulfate byproduct is this process is ca. 0.8 kg per kg of caprolactam produced. The hydroxylamine content in the solution amounts to ca. 115 g/L. 

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