USOO80441 66B2 (12) United States Patent (10) Patent No.: US 8,044,166 B2 Fiene et al. (45) Date of Patent: Oct. 25, 2011 (54) PROCESS FOR PREPARING (56) References Cited PENTAMETHYLENE 1.5-DIISOCYANATE U.S. PATENT DOCUMENTS (75) Inventors: Martin Fiene, Niederkirchen (DE); 5,103,045 A * 4/1992 Robin et al. .................. 560,335 Eckhard Stroefer, Mannheim (DE); 2005, OOO3497 A1* 1/2005 Nishi et al. .................... 435/128 Wolfgang Siegel, Limburgerhof (DE); Stephan Freyer, Neustadt (DE); Oskar FOREIGN PATENT DOCUMENTS DE 1900 514 8, 1970 Zelder, Speyer (DE); Gerhard Schulz, DE 26 25 O75 A1 12, 1977 Bad Duerkheim (DE) DE 2625 O75 * 12, 1977 EP O 259 233 A2 3, 1988 (73) Assignee: BASF Aktiengesellschaft, EP O 161419 B1 8, 1989 Ludwigshafen (DE) EP 1482 055 A1 12, 2004 GB 1 225 450 3, 1971 (*) Notice: Subject to any disclaimer, the term of this WO WOO3,O99768 A1 12/2003 patent is extended or adjusted under 35 WO WO 2006.005603 A1 1, 2006 U.S.C. 154(b) by 336 days. OTHER PUBLICATIONS (21) Appl. No.: 12/373,088 Database Caplus Chemical Abstracts Service, Columbus, Ohio, US 1979, T. Lesiak etal "Preparation of Aliphatic diisocyanates without (22) PCT Fled: Jul. 25, 2007 using phosgene” XP002456997.* Enzyme Handbook, Dec 1, 1982, by Asakura Shoten.* (86) PCT NO.: PCT/EP2007/057646 Preparation of Aliphatic Diisocyanates without using Phosgene, Jun. 1969, by Sea Lesiak.* S371 (c)(1), T. Lesiak, et al., “Preparation of aliphatic diisocyanates without using (2), (4) Date: Jan. 9, 2009 phosgene'. Journal f. prakt. Chemie. Band 321, XP002456997. 1979, pp. 161-163, Derwent Abstract attached. (87) PCT Pub. No.: WO2O08/O15134 Guy Gautret De La Moricière, et al., "La décarboxylation de la PCT Pub. Date: Feb. 7, 2008 lysine”. Bulletin De La Société Chimique De France, No. 12, 1969, pp. 4421-4425. (65) Prior Publication Data U.S. Appl. No. 12/446,460, filed Apr. 21, 2009, Boehling et al. US 2009/O2921 OO A1 Nov. 26, 2009 * cited by examiner (30) Foreign Application Priority Data Primary Examiner — Randy Gulakowski Assistant Examiner — Jeffrey Washville Aug. 1, 2006 (EP) ..................................... O61182.56 (74) Attorney, Agent, or Firm — Oblon, Spivak, (51) Int. C. McClelland, Maier & Neustadt, L.L.P. COSG 18/00 (2006.01) CD7C 263/2 (2006.01) (57) ABSTRACT CD7C 263/ (2006.01) CI2PI3/00 (2006.01) The present invention relates to a process for preparing pen (52) U.S. C. .......... 528/85; 560/348; 560/347; 560/355; tamethylene 1,5-diisocyanate, to pentamethylene 1,5-diiso 435/128 cyanate prepared in this way and to the use thereof. (58) Field of Classification Search ........................ None See application file for complete search history. 13 Claims, No Drawings US 8,044,166 B2 1. 2 PROCESS FOR PREPARING The pentamethylene 1,5-diisocyanate prepared in accor PENTAMETHYLENE 1.5-DIISOCYANATE dance with the invention has, in contrast, a proportion of the branched pentamethylene diisocyanate isomers of in each The present invention relates to a process for preparing case less than 100 ppm. pentamethylene 1,5-diisocyanate, to pentamethylene 1,5-di The present process therefore further provides a mixture isocyanate prepared in this way and to the use thereof. consisting of at least two different pentamethylene diisocy The preparation of pentamethylene diisocyanate from 1.5- anate isomers, of which the main constituent is pentamethyl pentanediamine is known perse and can be effected without ene 1,5-diisocyanate, and the isomer present in Smaller phosgene (T. Lesiak, K. Seyda, Journal für Praktische Che amounts is presentinamounts of not more than 100 ppm, with mie (Leipzig), 1979, 321 (1), 161-163) or by reaction with 10 the proviso that the sum is 100% by weight. phosgene (e.g. DE 2625075). The present process further provides a mixture consisting DE 1900514 (corresponding to GB 1225450) describes the of pentamethylene 1,5-diisocyanate and pentamethylene 1,4- two-stage preparation of pentamethylene 1,5-diisocyanate diisocyanate, where the proportion of pentamethylene 1,4- from caprolactam by conversion to the hydroxamic acids and diisocyanate amounts to not more than 10 000 ppm, prefer the Subsequent phosgenation thereof. 15 ably 7500 ppm, more preferably 5000 ppm, even more The yield reported in this document for the conversion of preferably 2500 ppm, in particular 1000 ppm, especially 500 caprolactam to pentamethylene 1,5-diisocyanate is only ppm and even 100 ppm, and the proportion of pentamethylene approx. 32%. 1,5-diisocyanate makes up the remainder to 100% by weight. Caprolactam is prepared on the industrial scale either in Consequently, the pentamethylene 1,5-diisocyanate pre several stages from benzene by ring hydrogenation to cyclo pared in accordance with the invention has virtually exclu hexane, oxidation to cyclohexanone and Beckmann rear sively two primary isocyanate groups and therefore exhibits a rangement with hydroxylamine, or from 1,4-butadiene by more homogeneous reactivity in conversions of the isocyan hydrocyanation and selective hydrogenation and Subsequent ate groups, for example in the preparation of polyurethanes. cyclization to the caprolactam. In both cases, the basis is a 25 Branched pentamethylene diisocyanate isomers, in contrast, hydrocarbon from petrochemistry. have one primary and one secondary isocyanate group, which This is therefore a petrochemistry-based preparation over are of different reactivity. five stages in each case, proceeding from benzene or from The pentamethylene 1,5-diisocyanate obtained by the pro butadiene. cess according to the invention generally has a color number The preparation of 1.5-pentanediamine is known by enzy 30 of not more than 15 APHA to DIN ISO 6271. matic decarboxylation of lysine with, for example, lysine The inventive step b) consists of a conversion of lysine to decarboxylase (EP 1482055 A1 or JP 2004-222569 A) in a 1.5-pentanediamine. cell-free system or by thermal or catalytic decarboxylation Lysine can be used in pure form or can actually be formed (G. Gautret de la Moriciere, G. Chatelus, Bull. Soc. Chim. in the course of the reaction (see below for step a)). In addi France, 1969, 12, 4421-4425) or by hydrogenation of the 35 tion, lysine can in the form of an aqueous solution, buffer corresponding nitriles (for example EP 161419 or WO 2003/ Solution or in the form of alysine-containing reaction mixture 99768). with alysine content of preferably from at least 5% by weight 1,5-Pentanediamine has to date not been available on the up to the solubility limit in the particular reaction mixture at industrial scale. 40 the particular temperatures. In general, the content may be up WO 2006/005603 describes a biochemical process for pre to 45% by weight, preferably up to 40, more preferably up to paring 1,4-butanediamine from ornithine with the aid of orni 35 and most preferably up to 30% by weight. thine decarboxylase and the use thereof as a starting com The lysine (2,6-diaminohexanoic acid) used for the process pound for polyamide preparation. according to the invention originates from preferably biologi It was an object of the present invention to prepare pen 45 cal material and may be present in the form of the Denanti tamethylene 1,5-diisocyanate which can be prepared from omer, in the form of the Lenantiomer or in the form of any renewable raw materials. mixture of these enantiomers, for example in the form of a This object is achieved by a process for preparing pentam racemate, preferably in the form of the Lenantiomer (S)-2, ethylene 1,5-diisocyanate, in which 6-diaminohexanoic acid. b) lysine is converted to 1.5-pentanediamine and 50 It can be used in free form or as an internal salt, in the form c) the 1.5-pentanediamine thus obtained is converted to pen of its anion as a carboxylate, or mono- or diprotonated in the tamethylene 1,5-diisocyanate. form of its mono- or diammonium salt, for example as the The advantage of the process according to the invention is chloride. based on independence from mineral oil as the raw material In addition, the lysine can be used in the form of its ester, basis in the preparation of the pentamethylene 1,5-diisocyan 55 for example as the methyl, ethyl, n-propyl, isopropyl. n-butyl, ate. In addition, the pentamethylene 1,5-diisocyanate pre sec-butyl or isobutyl ester. pared in this way has less color than that prepared conven Step b) is preferably a decarboxylation. tionally, since it is subjected to less thermal stress. In one possible decarboxylation, lysine, if appropriate dis As a result of the inventive selection of the raw material Solved or Suspended in a solvent, is heated at a temperature basis of lysine or renewable raw materials, the process 60 above 80° C., preferably above 100° C., more preferably according to the invention affords at least virtually isomeri above 120° C., even more preferably above 150° C. and in cally pure pentamethylene 1,5-diisocyanate, whereas the particular above 180° C. (thermal decarboxylation). pentamethylene 1,5-diisocyanate prepared by the conven The temperature may be up to 250° C., preferably up to tional route comprises a proportion of isomeric pentamethyl 230°C., more preferably up to 210°C. and most preferably up ene diisocyanates, especially pentamethylene 1,4-diisocyan 65 to 200° C. ate. Depending on its preparation, this proportion may be up If appropriate, pressure can be applied in order to keep any to several % by weight. Solvent present in the reaction mixture. US 8,044,166 B2 3 4 Examples of solvents are aromatic and/or (cyclo)aliphatic tions is preferred, in which case a nucleophile, preferably an hydrocarbons and mixtures thereof, halogenated hydrocar iodide or bromide, more preferably an iodide, is added to the bons, esters, ethers and alcohols.