IL29442A - Solventless process for exothermic addition reactions between aromatic amines and diketene,or phenols and isocyanates - Google Patents

Description

SOLVENTLESS PROCESS FOR EXOTHERMIC ADDITION REACTIONS BETWEEN AROMATIC AMINES AND OR PHENOLS ISOCYANATES a number addition reactions in organic in which a can with a reaatant with several and to produce an addition product hich is in which reaction goos can run in the reaction proceeds at the molting point of the product in much fashion it doea at lower and despite the exothermic it is possible to control the reaction the products conventional heat exchange many reactions cannot be in t because at reactions which substantiall reduce the yield of the desired contaminate the produc that with attendan loss and is Such are conventionally run either solution or in in diluent so that the reaction carried out at low and the product is separated f the vehicle and purified as One such reaction is addition of amines to produce An tionally sa isfactory method for such in the ence of water he diluent vehicle consists of reacting a or in Which the amino group is attached directl to an aromatic carbocyclio in aqueous with diketcne with very vigorous agitation at temperature of about by simultaneously adding the two in substantially ic proportions at essentially the at which they that any substantial of is presence of to by weigh of water for each part of Reactions in absence of diluents to produce solid end products have been conducted form r it proposed to produce powdered for by conducting such reactions equipment which keeps the polymer broken so that there is no need break u the final product after polymerisation fo example of the reaction product is essentially the as the product produced in the absence of Xn accordance with the present we conduct exothermic addition reactions of organic material A with second organic material to produce solid at ambient in good yields and in commercially acceptable powdered b reacting A with in a at temperatures below melting point of the and suf low to prevent undesirable side while subjecting the reactants and the product to sufficient agitation intensive mechanical keep product in particulate form while removing heat prevent fusing of the the reactants being added in such proportions as any substantial either where neither reactant is very readily volatile Most reaction is carried out in the presence of a substantial exces of product as whereby the temperature control is most readily As described the la concerned with exothermic organic addition reactions which produce solid end and are conventionally run in diluents rathe than as because of undesirable side reactions at or the mentioned above in the discussion of the field of the they ore below in the reactions of phenols and to produce reaction amines and to produce In accordance with ou the are fe into a reaction which vigorously agitated with power to keep the product of the reaction broken up in powder The solid reaction for end helps in preventing the building up of hea the reaction is initiated with heel of product put the to control the heat of the although of product heel can be dispensed with where the reacto is provided sufficien cooling in the walls and blad The may be run batchwise or Whe operating a batch any intensive can be for horizontal as a Banbury mixer is and filled with sufficient product so that the works on the delivers i to a point acent to the entry ports the Th are fed the mac ine the at a sufficient slow rate to prevent their over about 10 00 they the rotating final they are converted final This continued until the mixer a portion o material ie discharged and the process When the process is operated reaction trough provided with feed points at one end and a discharge gate at the opposite intensive mixer is operated in the The rate f feed is by the ca acit of the reactor and the residence time re uired to complete keeping mind the necessity keeping the percentage feed low enough th of sufficiently heavy body to maintain proper acti The nay bo liquid or and one bo they must add to form and the be at a mixers do not act properly with mixtures hich not it to carry ou tho reaction in presen of a substantial excess of produc particularly wh raw materials are ensures the heav body to the mixer run and likewise gives mor effective control of the exothern the products are to preferably with the store Volatile reactant i to push the reaction to and ta excess of reactant mply evaporated from the neither reactant is readily from the substantially amounts f materials are an the product is used it from the making the diketene about percent or more he aromatic be a monoamine or a and the amino group la attached directly to the carbocyclio in colored in the case of any ami has a color of 100 or less is As indicated the feed rates would be such aa to keep the amounts of nroacte materials low relative finished ar lamides in required for completion o the reaction of about S to 30 at reasonable rates a above tout it should kept below the point of the Xn using continuous it is poaeible to be at temperatures where the reaction la liquid or at the where the amou of unreacte is provided it is at th temperatur range of is Atmospheric pressures are suitable fo the process b since volatile it generall desirable to operate in a closed mixer and allow the pressure to buil u to the autogenic pressure of the vapor the tempera of high pressure can be used so pressure not a limiting factor in this The reaction time will of on the used malting oaee a and accordance wit the hydroxy compound may be a liquid or a The used are generally ary isocyanates either liquid or he reaction carried o in the presence f conventional such as the isocyanate la generally the more volatile a sli excess of 1 to 5 percent is generall i order to conversion of the hydroxy and excess evaporated in conventional amount of catalyst vise depends on the reactivity of the Approximately on percent is with the highly reactive somewhat highe concentrations are needed the active varies cording to the specific and is affected greatly by identity and concentration of catalyst and intensity The following specific examples of two of products and arc given by way not wa Of 1 A liter Banbury with twin blades having of with of and aniline fed at a of about 1 to per minute while maintaining reactio temperature of After 22S and 250 had a sample product h a point of and completely soluble 5 perce aqueous additional of a aniline added 40 minute period a rea temperature The product w acetoacetanil by point and caustic 2 was prepared in the of diketene to to mole percent in of the After evaporating of the excess the vas white powder which gave solution of 3 percent ha a melting point of io Gardner Color and were at about 3 per minute concurr feed contr lled to at o percent The temperature between 35 by addition periodically t accumulated product the reaction continued until a total of 2500 arylide had been produc A the when had a point of was soluble in gave a solution col 30 unite aa a S peccant solution in 4 17 liter having blade clearance of and turning at 133 was with of fed at of per at one of the horizontal maximum of Product aa removed continuously through an overflow gate at opposite end the a per arylide th run in aqueoua aaaayed percent and had a point of aver residence time the reactor 30 process of Example e a blade clearance and at feed to produce of pro per The temperature was at the The product waa caustic The average residenc waa about 15 The reaction was conducted continuously i a Patter a continuously discharging intensive mixer over flowing a retaining dan The jacketed for cooling an the for internal cooling water was applied to finished product was charged to t e with closed The aromatic with by of triethyl he at o per hou methyl ieocyanate introduced fi the of per hour percent molar reactor was appropriately vented a ecrubber for disposal of vapora of the very toxic methyl When the leve l of solids had become uniform throughout the the opene allow overflow into a product gradien through the reactor overflowed in the of melting at Xn two hour of of produc content of insufficientOCRQuality

Claims (7)

29442/ 2

1. Process of producing a solid addition product of at least two organic reactants by an exothermic reaction between the reactants in the absence of diluents, in which the reaction cannot be carried out above the melting point of the product because of undesirable side reactions, characterized by feeding the reactants into a zone of intense agitation and conducting the reaction under agitation which is sufficiently intense to keep the product in a finely divided state, while maintaining the temperature sufficiently high to induce the desired addition reaction but sufficiently below the melting point of the product to substantially prevent the occurrence of undesirable side reactions, to obtain the product in solid comminuted form in a high state of purity, the reactants being (a) a primary amine from the grou consisting of arylamines and aryldiamines in which the amino groups are attached directly to the aromatic carbocyclic nucleus, and diketene, or (b) a phenol and an isocyanate, in near stoichiometric proportions.

2. The process of claim 1, characterized in that the raw materials are fed into a heel of the comminuted reaction product.

3. The process of claim 1 or 2, characterized in that the raw materials are fed into a heavy-duty mixer and a heel of reaction product is maintained in sufficient concentration to permit efficient operation of the mixer.

4. The process of any of claims 1-3, characterized in that a slight excess of the more volatile reactant is used, and the excess is removed from the reaction product by evaporation.

5. The process of any of claims 1 -4, characterized in that the process is run continuously, and the product is rem oved at the opposite end from the feed end.

6. The process of any of claims 1-5, characterized in that the reaction temperature is maintained above 0°€ and sufficientl below 150°C to avoid meltin the roduct. 29442/2

7. The process of any of claims 1-6, characterized in that the reactants are 2, 3-dihydro-2, 2 -dimethyl- 7 -benzofuran and methyl isocyanate. S. HOROWITZ & CO. AGENTS FOR APPLICANTS