CH476057A - Process for the production of polyhydantoins - Google Patents

Description

  

  



  Process for the production of polyhydantoins
The invention relates to a new process for the preparation of polyhydantoins.



   It has been found that polyhydantoins are obtained if polyfunctional derivatives of N-carboxyglycines with polyamines, optionally in an organic solvent, are heated to temperatures of up to 5000.degree.



   Glycine derivatives in the context of the present invention are compounds of the general formula
EMI1.1
 In the formula, Ar is an aromatic radical, R1 = hydrogen or alkyl, R2 = OH, an amino group, an alkylamino group, dialkylamino group, alkoxy group or aroxy group, R3 is a dialkylamino, alkoxy or aroxy group and x is an integer from 2 to 4. The glycine derivatives to be used according to the invention are therefore required to have the remainder
EMI1.2
 must contain at least twice in the molecule.



   The aromatic radicals Ar are, in particular, radicals derived from benzene, azobenzene, naphthalene, anthracene, triphenylmethane, diphenyl, diphenylmethane or diphenyl ether. These radicals can also be substituted one or more times, for example by alkyl (methyl), halogen (chlorine), nitro, alkoxy (methoxy), dialkylamino (dimethylamino), acyl (acetyl), Carbalkoxy (carbometh or ethoxy) and cyano groups. The benzene, naphthalene, diphenylmethane or diphenyl ether derivatives which are optionally substituted once or twice by methyl and / or chlorine functions are preferred. The glycine derivatives to be used as starting materials according to the invention are prepared by methods which are known in principle. By direct reaction of corresponding aromatic polyamines with hydrocyanic acid and aldehydes or

   Ketones with subsequent conversion of the nitrile group into a desired carboxyl function, for example carboxylic acid, ester or amide, or by condensation of the aromatic polyamines with haloacetic acid or its derivatives, the underlying glycine derivatives with a free NH function are formed, which are then combined with a chlorocarbonic acid alkyl or aryl esters can be converted into the desired starting materials. The reactions with the haloacetic acid or its derivatives and the chlorocarbonic acid derivatives take place in the sense of a Schotten-Baumann reaction, e.g. B. in organic solvents such as ethanol, methanol, acetone or benzene, or in an aqueous medium with the use of acid scavengers such as tert.

   Amines (pyridine, triethylamine), excess starting amine, soda, potash, sodium hydroxide, potassium hydroxide, calcium oxide or calcium carbonate.



   Details of this process stage and the starting materials to be used are described in more detail in French Patent No. 1,484,694.



   The subsequent condensation with the Chlorkoh lensäurealkyl- or -arylesters, z. B. chlorocarbonic acid methyl, ethyl, propyl, phenyl or tolyl ester takes place under practically the same conditions. Here, individual process stages, e.g. B. Condensation reactions with chloroacetic acid derivatives and chlorocarbonic acid derivatives can be summarized in a corresponding manner in a reaction stage. Another way of preparing the glycine derivatives to be used according to the invention consists in the condensation of the corresponding carbamic acid esters having a free NH group with a chloroacetic acid derivative, generally via the salt of the carbamine ester.



   The polyfunctional glycine derivatives obtained in this way contain at least two groups
EMI2.1
 are used to prepare the polyhydantoins with a primary polyamine, i. a compound with at least two primary amino groups, reacted at elevated temperature. The reaction can for example be given by the equation below: can be taken up immediately in a solvent towards the end of the condensation or even after the desired degree of condensation has been achieved.

   In general, for processing reasons, the condensation is not carried out to the desired end state; this can, after shaping, casting into a film or a foil, or after application to a substrate, by a thermal aftertreatment in the temperature range between 100 and 5000 ° C., preferably between 150 and 4000 C. Here, other polymeric substances such. B. polyesters, polyamides, polyurethanes, polyolefins. Polyacetals, polyepoxides, polyimides, polyamides
EMI2.2

Suitable polyamines for the purpose of reaction with the glycine derivatives described above are, for. B. aliphatic, cycloaliphatic or particularly aromatic compounds with at least two primary amino groups in the molecule.

   Examples of such polyamines include: a, o-diaminoalkanes with 2 to 18 carbon atoms in the molecule such as ethylenediamine, propylenediamine-1,2 and -1,3, 1,4-diaminobutane, hexamethylenediamine or octamethylenediamine, also their alkyl Substitution products and polymers such as trimethylhexamethylenediamine, diethylenetriamine, triethylenetetramine or dipropylenetriamine, aromatics containing aminomethyl groups such as 1,3- or 1,4-xylylenediamine, and also the aromatic polyamines listed in the preparation of the glycine derivatives.



   The process is generally carried out by heating the two components, preferably in stoichiometric amounts, to an elevated temperature in order to carry out the aminolysis outlined in the above equation. This reaction is preferably carried out at least towards the end using an organic solvent. Suitable solvents are inert organic solvents such as aliphatics, aromatics, halogenated hydrocarbons, N-alkyl-pyrrolidones, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, phenol or cresols are particularly suitable.



   The condensation of the components generally takes place in the range between 100 and 3500 ° C., especially 140 to 2800 ° C., by initially preparing a precondensate without a solvent, the molecular weight of which is increased as the reaction proceeds at an elevated temperature. The condensation reaction can also be activated by using acidic, alkaline or metal catalysts (soda, caustic soda, endoethylene piperazine, triethylamine, phosphoric acid, p-toluenesulphonic acid, sodium phenolate, lead oxide or titanium tetrabutoxide).



   The choice of the proportions of glycine derivative and amino component as well as the reaction conditions determine the degree of condensation of the resulting polymers, which contain several hydantoin groups in the molecule. Polymers with higher molecular weights, i.e. For example, over several thousand, imides, polyimino polyesters, polyimide isocyanates, etc. are also used, which are linked directly to the polyhydantoins if functional groups (OH or NCO groups) are present.



   The hydantoins accessible by the method of the invention are temperature-resistant plastics that can be processed and used as temperature-resistant coating materials according to French Patent No. 1,484,694. The following examples explain the process described.



   Example 1 a) 198 parts by weight of 4,4'-diaminodiphenylmethane, 200 parts by weight of calcium carbonate and 1500 parts by weight of water are heated to 800.degree. C. and at this temperature 244 parts by weight of ethyl chloroacetate are added dropwise. The mixture is kept at 800 ° C. for 2 hours and a further 217 parts by weight of ethyl chloroformate are then added dropwise. After the evolution of carbon dioxide has ended, the organic phase is separated from the aqueous calcium chloride solution, washed several times with hot water and taken up with approximately equal parts by weight of ethanol. Small amounts of 4,4'-bis (N-carbäthoxymethylamino) diphenyl methane precipitate.

   After concentrating the ethanolic solution, the desired 4,4'-bis (N-carbäthoxymethyl- -N-carbäthoxy) -diphenylmethane remains as a viscous residue, the IR spectrum of which clearly agrees with the assumed structure. b) 51.4 parts by weight of the glycine derivative obtained according to a) and 19.9 parts by weight 4,4'-diaminodiphenyl methane are first heated to 2000 ° C. in a stirred flask under nitrogen. Even small amounts of ethanol distill off during this process. The temperature is now slowly increased to 2500 C in the course of 10 hours and left at this temperature until the mass can hardly be stirred.

   By adding cresol, a 350J solution is established which in the IR spectrum clearly has the typical absorptions for a hydantoin configuration. c) Instead of diaminodiphenylmethane, 20.1 parts by weight of 4,4'-diaminodiphenyl ether or 10.8 parts by weight of p-phenylenediamine can be used in an example analogous to b). d) The solutions of polyhydantoins in cresol obtained by the above methods can be used in the usual way by machine for coating copper wires according to French patent specification No. 1,484,694 and provide temperature-resistant insulating coatings.



   Example 2 a) 280 parts by weight of 1,3-bis (N-carbethoxymethyl-amino) -benzene are heated to 700 ° C. with 1000 parts by weight of water and 100 parts by weight of calcium carbonate and then 217 parts by weight of ethyl chloroformate are added dropwise. Working up is carried out as in Example 1 a) and provides the desired 1,3-bis (N-carbethoxymethyl-N-carbethoxy-amino) benzene, identified by IR spectroscopy. b) Analogously to Example 1 b) 42.4 parts by weight of the glycine derivative obtained according to Example 2a) are condensed with 19.9 parts by weight 4,4'-diaminodiphenylmethane to form a polymer containing hydantoin groups, which is taken up in the form of a 40% intrinsic cresolic solution and z. B. is used for painting sheet metal.

   The coatings obtained in this way correspond, according to their IR spectra, measured according to the reflection principle, to the polyhydantoin coatings obtained according to French patent specification No. 1,484,694.

 

Claims (1)

PATENT CLAIM Process for the preparation of polyhydantoins, characterized in that one glycine derivatives of the general formula EMI3.1 in which Ar is an aromatic radical, Rt is hydrogen or alkyl, R2 is hydroxyl, an amino, alkylamino, dialkylamino, alkoxy or aroxy group, R3 is a dialkylamino, alkoxy or aroxy group and x is an integer from 2 to 4, reacts with compounds containing at least two primary amino groups in the molecule.