Recovery of n-vinylformamide

[Detailed Description of the Invention]

[Industrial Application] The present invention relates to the method of collecting N-vinyl Holm amide. [Description of the Prior Art] It is useful as polymerization nature top Tsuma- which gives the water-soluble polymer which has the outstanding flocculation performance, and N-vinyl Holm amide is Ah, and its manufacturing process and Do, For example, as shown in the following equation, Yo diether is formed to the y-(alpha-hydroxyethyl) Holm amide all alcohol produced by making acetaldehyde and Holm amide react, and it is M (considering it as alpha-alkoxy Echi] Holm amide). Subsequently, the method of obtaining Yo fiN-vinyl Holm amide to carry out thermal decomposition of Colet at high temperature is learned, and it is b To. Namely, the following equation: % Formula % In an above-mentioned method, N-vinyl Holm amide is collected as a thermal decomposition mixture with the alcohol which carries out subraw to the thermal decomposition of N-(alpha-alkoxy ethyl) Holm amide for a Yo Si profitable To be reason. So, it is necessary to distill this mixture and to usually isolate N-vinyl Holm amide. By the way, the method of a thermolysis reaction is although it differs in the kind of alcohol used for etherification, Usually, the method of carrying out thermal decomposition by M - (alpha-alkoxy ethyl) Holm friend drama gaseous phase, and carrying out condensation recovery of the thermal decomposition mixture of the profit ratio above, Or since the method of carrying out thermal decomposition is adopted, distilling off H-vinyl Holm amide and alcohol which generate N-(alpha-alkoxy ethyl) Holm amide under heating by the liquid phase, in which case, N-vinyl Holm amide will be collected as a mixture with alcohol. [Problem(s) to be Solved by the Invention] however, the above should be caused conventionally -- the case of N-vinyl Holm amide and alcohol where thermal decomposition mixture all distilled and N-vinyl Holm amide is collected, N-vinyl Holm amide needle is not foolish Si to whom the recovery straw of decomposition L and w-vinyl Holm amide falls in the middle of M Distant, There was a problem that it was desirable Si and to stop [ that the impurities which were collected and arose in that decomposition in Light-roofing-vinyl Holm amide contain, and ] that content as few as possible since these impurities moreover have a bad influence also on the polymerization nature of N-vinyl Holm amide. An object of the present invention is to provide the method of collecting N-vinyl Holm amide by distillation of the thermal decomposition mixture of N-vinyl Holm amide and alcohol which can solve the above-mentioned conventional problem. [Means for Solving the Problem] For these artificers, as a result of examining many things that this object should be achieved, by thermal decomposition of N-(alpha-alkoxy ethyl) Holm amide, a little basic impurities are subraw Tooth, These basic impurities exist in a thermal decomposition mixture of N-vinyl Holm amide and alcohol, and are promoting decomposition of N-vinyl Holm amide of distillation time, And it found out that boiled this thermal decomposition mixture as if specific cationic exchange resin is contacted beforehand, and distillation recovery of the N-vinyl Holm amide of high purity was carried out by quantity yield for the first time, and reached the present invention in it. Namely, the present invention distills a mixture which obtains by carrying out N (alpha-alkoxy ethyl) Holm friend truck thermal decomposition, and contains 7tN-vinyl Holm amide, and is N-vinyl Holm amide t. - He is Ah fc Si for collecting, Let a method of collecting N-vinyl Holm amide carrying out contact processing of the mixture with weak acidic cationic exchange resin beforehand be a gist. First, be shown in the conventional thermal decomposition mixture, i.e., the equation, containing N-vinyl Holm amide used as one charge of a method of collecting the present invention, A mixture and its distilling method of usual ON-vinyl Holm amide and alcohol which carry out the etherification reaction of the N-(alpha-hydroxyethyl) Holm amide with alcohol, obtain, and are produced by carrying out thermal decomposition of the 7tN-(alpha-alkoxy ethyl) Holm amide by the gaseous phase or the liquid phase are explained in detail. An etherification reaction of N-(alpha-hydroxyethyl) Holm amide and alcohol, Usually, it is the temperature of 0~100degreeC, preferably It-30-degreeC, and, for example under existence of mineral acid catalysts, such as sulfuric acid, chloride, and phosphoric acid, it carries out until conversion straw of charge of ffi 0N-(alpha-hydroxyethyl) Holm amide will be more than to%, preferably 90% or more. As alcohol used here, they are usually methanol and ethanol, Fatty series lower alcohol or triethylene glycol of 7 values, such as a proper tool, Univalent fatty alcohol, such as - or J, j-butanediol, polyethylene glycols of molecule fikJ 00~4theta00, or polypropylene glycol, etc. are mentioned in diethylene glycol, propylene glycol,/, J+, l, and 4. Although alcohol is usually used in excessive amount in this etherification reaction to serve also as a solvent, Since 6 To N-(alpha-alkoxy ethyl) Holm amide dissolves with an etherification reaction product although N-(alpha-hydroxyethyl) Holm amide which is materials does not carry out the Mostly dissolution at the system of reaction, perfect homogeneous-mixing solution is obtained at the time of an end of a reaction. Although a mixture which carries out thermal decomposition of the N-(alpha-alkoxy ethyl) Holm amide obtained above, and contains N-vinyl Holm amide by the following A is obtained, use at the above-mentioned etherification reaction and sense alcohol be [ s ] alike -- since quality of JN-(alpha-alkoxy ethyl) Holm amide differs -- thermal decomposition -- this kind -- Aspiring, gaseous phase method, or liquid phase method Yo Si To be done. as the method of thermal decomposition -- "(alpha-alkoxy ethyl) Holm amide -- usually -- below ■lambdatOwsHg -- desirable How to carry out condensation recovery of the Including tr steam for N-vinyl Holm amide obtained by carrying out thermal decomposition by the gaseous phase at temperature of 00 degrees of 20O~Hiroshi C under decompression of gO-13OBT1g, and alcohol, or if it heats and generates to temperature of 20~+20 theta°C, preferably l piece oNit theta°C below ■lambdathetawtaHg, preferably under decompression of /and -/thetaWHg, a method of distilling off 1 vinyl Holm amide and alcohol and carrying out thermal decomposition by the inside liquid phase will be mentioned. In any case, by these thermal decomposition methods, i To be N-vinyl Holm amide is collected as a mixture with subraw To shake alcohol. Therefore, in order to isolate N-vinyl Holm amide, it is necessary to distill these thermal decomposition mixtures. This distillation responds to the boiling point of alcohol separated since the boiling point of father-in-law-vinyl Holm amide for example, in 31Hg is about 70degreeC, and is under decompression! That condition is suitably selected at temperature of theta~130 degreeC. if in charge of distillation although it is considered as materials of distillation of a thermal decomposition mixture which contains ON-vinyl Holm amide conventionally which was produced by making it above in a method of collecting the present invention -- materials f: -- let it be indispensable requirements to carry out contact processing with weak acidic cationic exchange resin beforehand. In namely, the inside of the conventional thermal decomposition mixture containing N-vinyl Holm amide collected by above-mentioned thermal decomposition, A little basic impurities contain, Steam @ Deeply carries out this - as it is, and it is in 9 cases, the distillation middle -- a mushroom -- a problem that a part of - vinyl Holm amide decomposes, and not foolish Si to whom a recovery rate of father-in-law-vinyl Holm amide falls but a little impurities which are collected and have a bad influence into 9N-vinyl Forma Z Do at a polymerization are contained -- Buddy 9. However, these problems are canceled by carrying out contact processing of such a conventional thermal decomposition mixture with weak acidic cationic exchange resin beforehand. Although it is marketed and cationic exchange resin of an acrylic acid series of h To Ha or a methacrylic acid series is usually mentioned as weak acidic cationic exchange resin used by the present invention, especially a thing of an acrylic acid series is desirable. Contact processing with a thermal decomposition mixture and cationic exchange resin containing N-vinyl Holm amide is resin t, after adding resin and agitating for a predetermined period in a method of usually dipping a thermal decomposition mixture in a column filled up with resin, or a thermal decomposition mixture. - One method of methods of carrying out door-to-door is adopted. a case where it is usually the former although contact time differs somewhat on processing conditions -- space speed (s, V) o and Yo~ -- substance 1 -- being preferably adjusted by Fi/~/l (M-vinyl Holm amide conversion) -- a case of the latter -- j minute~j hours -- desirable -- company 0, It is ~ A time. Contact temperature is usually 0~100degreeC, preferably 10-$ theta°C. In the present invention, in carrying out contact processing of the thermal decomposition mixture with cationic exchange resin, if needed, the mixture may be diluted with water or alcohol, and may be used. A thermal decomposition mixture which performed above-mentioned contact processing is although basic impurities are removed and heat stability is good, this -- for example, -- if alkali compounds, such as a small amount of potassium hydrates, sodium hydroxide, and sodium carbonate, are added -- the heat stability of a mixture -- Yo Si -- since it improves further, it is desirable. In this case, Kv of Section 4 carries out and it adds an alkali compound so that pII at the time of diluting a pHC thermal decomposition mixture of a thermal decomposition mixture with twice [ 3 weight ] as many water as this may become the range of 6~r. [Example] Next, it is not limited to Yo Si and also Limit, and the following examples as for which the present invention does not exceed the gist although explained concretely by the present invention top example. Limit Si and the "% of the weight" that is not refused are expressed especially"%." Example no Hiroshi and comparative example 7 (manufacture of an ether body) 0 [ provided with the stirrer and the thermoregulator ], It obtains by making Holm amide and acetaldehyde react to t glass reaction machine under existence of a carbonic acid Cali Qum catalyst, and is 7'tN-(alpha-hydroxyethyl) Holm amide. (Hereinafter, it is called a "hydronalium Conflict Si object" for short) Crystal (it is 00-m content 0.j X to purity 77X, Holm amide content a, and Z#) j O, 9t - It teaches and is methanol j /to this! 9 and (it is mu Mol twice to the Si object in hydronalium) sulfuric acid theta, and lambdaj11 (shining to neutralization quantum hydroxy body of KtO0.) 3-mol %t - They are the bottom of - churning, and lambda moreover! By performing an etherification reaction (reaction time 3 hours), ranking next, adding lambda0X sodium hydroxide solution to this, and neutralizing a catalyst until the residue of the Si object in hydronalium within the system of reaction serves as lX at the temperature of ~muO degreeC, it is referred to as pHt7 and is a sense. 0 which carried out distillation recovery of the ether body under 31 kg of decompression after removing a part for light-boiling for this liquid under jO and decompression of H9 (manufacture of N-vinyl Holm amide) To ether body t obtained above, path 10 dawn provided with the heater, and the stainless pipe of length jOOllll, supplying at a rate of 277/- under decompression of A O0■Hg, maintaining an internal temperature at i and toodegreeC, and carrying out Yo Si thermal decomposition to on the other hand making A turtle discharged condense immediately -- distillate thing lambdaJif recovery of the following composition -- it carried out. N-vinyl Holm amide 67% methanol In addition to this, it is an organic ingredient 37%. 2% (Distillation of the thermal decomposition mixture containing M-vinyl Holm amide) It is weak acidic cationic exchange resin (Mitsubishi Kasei industrial stock system brand name diagram ion oyz) of R form to the distillate thing which is a thermal decomposition mixture obtained above. adding 2. -- the bottom of room temperature -- respectively -- the [ above-mentioned ] -- after performing contact processing on the conditions shown in 1.%, it carried out door-to-door [ of the resin ]. Methanol is respectively removed from obtained F liquid under decompression of 10■Ell separately, and also they are the bottom of decompression of 101Ell, and overhead 5 temperature! Distillate recovery of the N-vinyl Holm amide was carried out performing distillation for 30 minutes by 7 degreeC. While being collected here and asking for the remains top in Recovery obstruction and the tank bottom of ft-N-vinyl Holm amide, the polymerization test of recovery N-vinyl Holm amide is measured at the time to a Line 11 polymerization start, and it is a sense. A result is summarized at 7th ceremony of the following, and is shown. The l-th table i: (1) pH value when the thermal decomposition mixture after the rate (weight twice) (2) resin processing to a thermal decomposition mixture is diluted with triple the amount of water (3) Carry out -O1 solution A of the N-vinyl Holm amide, and it is Hot summer of 250 degree[ this ] C, and is N, carrying out aeration -- a ratio -- the back carries out 3.DOOppm addition of J and the 2'-azobis amidinopropane salt WIt salt to 7 Tsuma- at this as a polymerization initiator The example at the time of adding Hydroxylate IJ Umu solution into the thermal decomposition mixture which carried out the side house of the time until a polymerization is accepted, and was performed on resin processing on the same conditions as 90 (4) example 3, and adjusting in the pHk neutral region of a mixture. (5) The example at the time of not carrying out resin processing of the thermal decomposition mixture at all. Comparative example - ~7 N-vinyl Holm amide was collected by the completely same method as Example 3 except having processed the thermal decomposition mixture using the publicly known adsorbent which is shown in the 2nd table and which is marketed to that of the weak acidic cationic exchange resin used in Example J, or I Si. A result is united with the 2nd table and shown. The-table [Effect of the Invention] According to the method of collecting present invention ON-vinyl Holm amide, contact processing of the Heat sharing mixture containing N-vinyl Holm amide is beforehand carried out with specific cationic exchange resin, The stability of (Z) N-vinyl Holm amide is raised at the time of distillation, the thing [ carrying out decomposition t and pigeon But prevention ] is possible, and it is Ah, O which can carry out N-vinyl Formamide recovery by the acid layer sharply higher than before as a result, and also the former, Although distillation recovery of the Yo Si secondary raw Did do impurities was carried out at decomposition of N-vinyl Holm amide at the time of distillation, it mixed in very small quantities into fcN-vinyl Holm amide and Dough of the five bad influences was carried out at the polymerization reaction, Since those impurities hardly exist according to the method of collecting the present invention, good N-vinyl Holm amide of polymerization nature can be obtained by quantity yield very easily.