Polytriazines and a process for their production

Mixtures of aliphatic, cycloaliphatic or aromatic polyfunctional N-cyanosulfon amides and aromatic polyfunctional cyanic acid ester are converted at 30.degree. to 150.degree. C into fusible prepolymers or prepolymers soluble in organic solvents (polymeric N-organo-isourea ethers). Said prepolymers are highly stable in storage and react at 150.degree. - 350.degree. C to high molecular weight polymers of of triazine structure which are insoluble in solvents and infusible. The prepolymers may be used for the production of coatings or shaped articles or laminates.

This invention relates to high molecular weight polytriazines and to a 
process for their production by heat-treating soluble, polymeric 
N-cyano-isourea ethers which have in turn been obtained by the 
polyaddition of polyfunctional N-cyano-sulphonamides and polyfunctional 
aromatic cyanic acid esters. 
It is known from DT-PS No. 1,190,184 that high molecular weight 
polytriazines can be obtained by polymerising difunctional or 
polyfunctional aromatic cyanic acid esters at elevated temperature, 
optionally in the presence of polymerisation promoters. 
In addition, it is known from Japanese Application JA 6265/66 that primary 
diamines can be reacted with cyanogen halide to form di(cyanamides) which 
may be processed into polymers. 
The polymerisation of polyfunctional cyanamides of secondary amines with 
catalytic to more than molar quantities of mono- or poly-hydroxyl and/or 
thiol compounds at temperatures of from 50.degree. to 250.degree. C to 
form polymeric products, in also known, cf. DT-OS No. 1,595,651. 
Finally, a process for the production of macromolecular polyguanidines by 
reacting N,N' -dicyanamides of the formula NC--NH--R--NH--CN on their own 
or with an N,N'-dicyanamide of the formula NC--NR'--R--NR'CN (where R and 
R' represent hydrocarbon radicals), is known from NE-PS No. 55 826. 
It has now been found that high molecular weight polytriazines can be 
obtained by converting N-cyanosulphonamides corresponding to the general 
formula (I): 
EQU a(so.sub.2 --nh--cn).sub.n (I) 
in which 
A represents aliphatic, cycloaliphatic or aromatic polyvalent radicals, 
optionally interrupted by bridge members, and 
n is a number from 2 to 5, 
With polyfunctional aromatic cyanic acid esters corresponding to the 
general formula (II): 
EQU ar(OCN).sub.m (II) 
in which 
Ar represents an aromatic radical or an aromatic radical interrupted by 
bridge members, and 
m is a number from 2 to 5, 
At elevated temperatures into a prepolymer which is soluble in organic 
solvents or into a fusible prepolymer (polymeric N-cyano-isourea ether), 
and allowing the prepolymer to react to completion at elevated 
temperatures to form a high molecular weight polymer of polytriazine 
structure which is substantially insoluble in solvents. 
It is preferred to react from 30 to 70 mol % of N-cyanosulphonamides of the 
formula (I) with from 70 to 30 mol % of aromatic cyanic acid esters 
corresponding to the formula (II). 
The invention also relates to mixtures which can be converted into high 
molecular weight polymers of polytriazine structure that are substantially 
insoluble in solvents, comprising 
A. N-cyanosulphonamides corresponding to the general formula (I): 
EQU a(so.sub.2 --nh--cn).sub.n (I) 
in which 
A represents an aliphatic, cycloaliphatic or aromatic radical optionally 
interrupted by bridge members, and 
n is a number from 2 to 5, and 
B. aromatic cyanic acid esters corresponding to the general formula (II): 
EQU ar(OCN).sub.m (II) 
in which 
Ar represents an aromatic radical or an aromatic radical interrupted by 
bridge members, and 
m is a number from 2 to 5. 
The mixtures preferably consist of from 30 to 70 mol % of 
N-cyanosulphonamides corresponding to the formula (I) and of from 70 to 30 
mol % of aromatic cyanic acid esters corresponding to the formula (II). 
The process according to the invention may be illustrated, for example, by 
the following equation (x &gt; 2), the terminal groups being cyanamide and 
cyanate groups: 
##STR1## 
In formula (I), A preferably represents a polyvalent aliphatic, 
straight-chain or branched-chain, saturated or unsaturated radical with 
from 1 to 20 carbon atoms, more especially with from 2 to 12 carbon atoms; 
a polyvalent cyclo-aliphatic radical with from 4 to 12 carbon atoms, more 
especially a 5-membered or 6-membered cycloaliphatic polyvalent radical; a 
polyvalent cycloaliphatic radical with from 4 to 12 and more especially 
with from 5 to 10 carbon atoms interrupted by C.sub.1 -C.sub.4 alkylene 
groups or by phenyl or by heteroatoms (O or S); a polyvalent aromatic 
radical with from 6 to 14 carbon atoms, more especially with from 6 to 10 
carbon atoms; one polyvalent aromatic ring with 6 to 14 carbon atoms, more 
especially with 6 carbon atoms, interrupted by C.sub.1 to C.sub.4 
alkylene, by oxygen by the carbonyl group (--CO--), by the carbonyl dioxy 
group 
##STR2## 
by the sulphonyl group (--SO.sub.2 --), or two such rings interrupted by a 
cycloaliphatic or aromatic 5-membered or 6-membered carbocyclic ring or by 
a single bond; and n is preferably the number 2 or 3, more especially the 
number 2. 
N-Cyanosulphonamides of the formula (I) in which A represents the aromatic 
radicals defined above are particularly preferred. 
The following compounds are mentioned as examples of compounds 
corresponding to the formula (I): 
hexane-di-(sulphonylcyanamide)-1,6 and isomers; 
benzene-di(sulphonylcyanamide)-1,3; -1,4; 
benzene-tri-(sulphonylcyanamide)-1,3,5; 
naphthalene-di-(sulphonylcyanamide)-1,3 and isomers; 
naphthalene-tri-(sulphonylcyanamide)-1,3,5; -1,3,6; -1,3,7; 
naphthalene-tetra-(sulphonylcyanamide)-1,3,5,7; 
diphenyl-di-(sulphonylcyanamide)-2,2'; -4,4'; -3,3'; -2,4'; 
diphenyl methane-di-(sulphonylcyanamide)-4,4'; -2,4'; 
diphenyl dimethyl methane-di-(sulphonylcyanamide)-4,4' and isomers; 
diphenyl sulphone-di-(sulphonylcyanamide)-3,3' and isomers; 
benzophenone-di-(sulphonylcyanamide)-3,3' and isomers; 
diphenyl ether-di-(sulphonylcyanamide)-4,4' and isomers; and 
cyclohexane-di-(sulphonylcyanamide). 
In the context of the invention, isomers are position isomers. 
The N-cyanosulphonamides of the formula (I) used in accordance with the 
invention may be obtained by reacting the corresponding sulphonic acid 
chlorides with cyanamide in accordance with Schotten-Baumann (cf. Methoden 
der Organischen Chemie, Houben-Weyl, fourth Edition, Vol. 8, page 177) or 
in accordance with Herbenstreit (J. Pr.[2], Vol. 41, pages 99 and 105). 
These compounds may also be prepared by reacting the corresponding 
sulphonamides with cyanogen halide in the presence of bases at 
temperatures of up to 65.degree. C. 
The aromatic cyanic acid esters of the formula (II) used in accordance with 
the invention are known compounds, for example from GB-PS No. 1,007,790, 
and may be obtained by the process described therein. 
From 1 to 1.1 mol of cyanogen halide and 1 mol of a base or base mixture 
may be used for every phenolic hydroxyl group. The reaction temperatures 
may be in the range of from -40.degree. to +65.degree. C. Suitable bases 
are inorganic bases, such as sodium hydroxide, potassium hydroxide, soda, 
potash, calcium hydroxide or tertiary amines, such as trimethyl amine or 
triethyl amine, whilst suitable solvents or suspending agents are water, 
alcohols, ketones, hydrocarbons chlorinated hydrocarbons or mixtures 
thereof. 
The aromatic cyanic acid esters preferably correspond to the general 
formula (III): 
##STR3## 
in which R represents hydrogen, halogen, linear or branched C.sub.1 - 
C.sub.9 alkyl or phenyl, several radicals R not having to be the same, or 
two adjacent radicals R on the same nucleus together form a carbocyclic 
5-membered or 6-membered ring or together and in conjunction with a hetero 
atom (O, S or N) form a 5-membered or 6-membered heterocyclic ring, alkoxy 
radicals with from 1 to 4 carbon atoms, or alkoxy carbonyl radicals with 
from 1 to 4 carbon atoms in the alkyl groups; 
R' has the same meaning as R or represents the group (IV): 
##STR4## 
B represents a single bond, an alkylene group with from 1 to 9 carbon 
atoms optionally substituted by C.sub.1 -C.sub.4 alkyl or phenyl, a 
cycloaliphatic or aromatic 5-membered or 6-membered ring optionally 
interrupted by oxygen, oxygen, the sulphonyl group (--SO.sub.2 --), the 
carbonyl dioxy group 
##STR5## 
or the carbonyl group; a is a number from 0 to 5 where e = 1, and a 
number from 2 to 5 where e = 0; 
b = 5 - a where e = 1, and 6 - (a + d) where e = 0; 
c = 5 - d; 
d is a number from 0 to 5; 
e = 0 or 1; 
with the proviso that the sum of a and d always gives a number from 2 to 
5. 
The symbols in formula (II) have the following meanings in particular: 
R = hydrogen, chlorine or bromine, C.sub.1 -C.sub.4 alkyl, methoxy, ethoxy, 
methoxy carbonyl, ethoxy carbonyl or butoxy carbonyl; 
B = a single bond, oxygen, the sulphonyl group, the carbonyl group, the 
carbonyl dioxy group, the methylene, ethylene or 2,2-propylene group 
##STR6## 
or the cyclohexylene radical; a = the number 1 where e = 1, and the 
number 2 where e = 0; 
b = the number 1 or 2, more especially the number 1; 
c = the number 1 or 2, more especially the number 1; 
d = the number 0 or 1, and 
e = the number 0 or 1, 
with the proviso that a + d = 2. 
The following are mentioned as examples of compounds which correspond to 
the formula (II); the di- and poly-cyanic acid esters, 1,3- and 
1,4-dicyanato benzene, 2-tert-butyl-1,4-dicyanatobenzene, 
2,4-dimethyl-1,3-dicyanatobenzene, 
2,5-di-tert.-butyl-1,4-dicyanatobenzene, tetramethyl-1,4-dicyanatobenzene, 
2,4,6-trimethyl-1,3-dicyanatobenzene, 4-chloro-1,3-dicyanatobenzene, 1,3-, 
1,4-, 1,5-, 1,6-, 1,7-, 1,8-, 2,6- 2,7-dicyanatonaphthalene and 
1,3,5-tricyanatobenzene; 
4,4'-dicyanatodiphenyl, 2,2'-dicyanatodiphenyl,3,3', 
5,5'-tetramethyl-4,4'-dicyanatodiphenyl, 3,3', 
5,5'-tetrachloro-4,4'-dicyanatodiphenyl, 3,3', 
5,5'-tetrachloro-2,2'-dicyanatodiphenyl, 2,2', 
6,6'-tetrachloro-4,4'-dicyanatodiphenyl, 
4,4'-bis-[(3-cyanato)-phenoxy]-diphenyl, 
4,4'-bis-[(4-cyanato)-phenoxy]-diphenyl; 2,2'-dicyanato-1,1'-binaphthyl; 
4,4'-dicyanatodiphenyl ether, 3,3', 
5,5'-tetramethyl-4,4'-dicyanatodiphenyl ether, 3,3', 
5,5'-tetrachloro-4,4'-dicyanatodiphenyl ether, 
4,4'-bis-[p-cyanatophenoxy]-diphenyl ether, 4,4'-bis-[p-cyanatophenyl 
isopropyl]diphenyl ether, 4,4'-bis-[p-cyanatophenoxy]-benzene, 
4,4'-bis-[m-cyanatophenoxy]-diphenyl ether, 
4,4'-bis-[4-(4-cyanatophenoxy)-phenyl sulphone]-diphenyl ether; 
4,4'-dicyanatodiphenyl sulphone, 3,3', 5,5'-tetramethyl-4,4'-dicyanato 
diphenyl sulphone, 3,3',5,5'-tetrachloro-4,4'-dicyanatodiphenyl sulphone, 
4,4'-bis-[p-cyanatophenyl isopropyl]-diphenyl sulphone, 
4,4'-bis-[(4-cyanato)-phenoxy]-diphenyl sulphone, 
4,4'-bis-[(3-cyanato)-phenoxy]-diphenyl sulphone, 
4,4'-bis-[4-(4-cyanatophenyl isopropyl)-phenoxy]-diphenyl sulphone, 
4,4'-bis-[4-(4-cyanatophenyl sulphone)-phenoxy]diphenyl sulphone, 
4,4'-bis-[4-(4-cyanato)-diphenoxy]diphenyl sulphone; 
4,4'-dicyanatodiphenyl methane, 4,4'-bis-[p-cyanatophenyl]diphenyl methane, 
2,2-bis-(p-cyanatophenyl)-propane, 
2,2-bis-(3,5-dimethyl-4-cyanatophenyl)-propane, 
2,2-bis-(3,5-dichloro-4-cyanatophenyl)-propane, 1,1-bis-[p-cyanato 
phenyl]-cyclohexane, bis-[2-cyanato-1-naphthyl]-methane, 
1,2-bis-[p-cyanatophenyl]-1,1,2,2-tetramethyl ethane, 
4,4'-dicyanatobenzophenone, 4,4'-bis-(4-cyanato)-phenoxy benzophenone, 
1,4-bis-[p-cyanatophenylisopropyl]-benzene, 2,2', 
5,5'-tetracyanatodiphenyl sulphone; and polycyanic acid esters of novolaks 
(reaction products of phenol or alkyl- or halogen-substituted phenols with 
formaldehyde in acid solution) containing from 3 to 5 OCN groups. 
In cases where it is desired to use particularly pure aromatic cyanic acid 
esters which are highly stable in storage, it is advisable to adopt a 
procedure similar to that described in German Patent Applications, our 
co-pending U.S. application Ser. Nos. 658,814 or 658,815 which relates to 
the production of highly pure polyfunctional cyanic acid esters. According 
to our copending U.S. application Ser. No. 658,814, filed Feb. 17, 1976 
di- or polytrialkyl ammonium phenolates (for example polytriethyl-ammonium 
phenolates) are reacted with an excess of a cyanogen halide in an organic 
solvent, optionally in the presence of catalytic quantities of trialkyl 
amines, such as triethyl amine, to form the corresponding aromatic cyanic 
acid esters. 
According to our copending U.S. application Ser. No. 658,815, filed Feb. 
17, 1976, alkali or alkaline earth metal salts, preferably sodium, 
potassium, calcium and barium salts of aromatic dihydroxy or polyhydroxy 
compounds, are reacted with a cyanogen halide in a solvent, optionally in 
the presence of catalytic quantities of a tertiary amine. 
From 1 to 2 mols and preferably from 1 to 1.4 mols of cyanogen halide and 
from 1 to 1.8 mols, preferably from 1 to 1.3 mols, of a base or base 
mixture may be used for every phenolic hydroxyl group, the base or the 
base mixture always being used in a deficit relative to the cyanogen 
halide. 
Examples of suitable solvents are water; lower aliphatic alcohols such as 
methanol, ethanol, propanol, isopropanol or butanol; aliphatic ketones 
such as acetone, methyl ethyl ketone, diethyl ketone, methyl isopropyl 
ketone or methyl isobutyl ketone; aliphatic or aromatic hydrocarbons, 
preferred aliphatic hydrocarbons being the fractions accumulating during 
distillation of naturally occurring mixtures, such as petroleum ether, 
light petrol or petrol, whilst examples of aromatic hydrocarbons are 
benzene, toluene and xylenes; aliphatic and aromatic chlorinated 
hydrocarbons, such as dichloromethane, dichloroethane, perchloroethylene, 
chlorobenzene or dichlorobenzene; ethers such as diethyl ether, 
diisopropyl ether, dioxane, teterahydrofuran or di-sec.-butyl ether; nitro 
hydrocarbons such as nitromethane, nitrobenzene or nitrotoluene; amides 
such as dimethyl formamide or dimethyl acetamide; and mixtures thereof. 
Suitable inorganic or organic bases are those mentioned in GB-PS No. 
1,007,790. 
These processes are generally carried out at temperatures in the range of 
from -40.degree. to + 65.degree. C and preferably at temperatures in the 
range of from 0.degree. to 30.degree. C. In cases where cyanogen chloride 
is used, the reaction is preferably carried out below the boiling point 
(13.degree. C), although where cyanogen bromide is used the reaction may 
even be carried out at temperatures above 50.degree. C. 
Tertiary amines, which are used in catalytic quantities (0.001 to 10% by 
weight, more especially 0.001 to 1.0% by weight, based on alkali or 
alkaline earth phenolate) in accordance with our copending U.S. 
application Ser. No. 658,815, filed Feb. 17, 1976 corresponding to the 
general formula: 
##STR7## 
in which R.sub.1, R.sub.2, R.sub.3 = alkyl, aryl and cycloalkyl radicals, 
which do not have to be the same as one another, with from 1 to 36 carbon 
atoms, more especially with up to 18 carbon atoms, such as for example 
trimethyl amine, triethyl amine, methyl diethyl amine, tripropyl amine, 
tributyl amine, methyl dibutyl amine, dinonyl methyl amine, dimethyl 
stearyl amine, dimethyl cyclohexyl amine and diethyl aniline. 
The process according to the invention may be carried out by reacting the 
polyfunctional N-cyanosulphonamides and the polyfunctional aromatic cyanic 
acid esters by heating to about 30.degree. - 150.degree. C, preferably to 
50.degree. - 100.degree. C, optionally in solution and optionally in the 
presence of a catalyst or catalyst mixture, to form uncrosslinked 
prepolymers (A) which are soluble in organic solvents. The prepolymers 
represent polymeric N-cyano-isourea ethers of wax-like or solid 
consistency and are soluble in organic solvents. They are highly stable in 
storage. As shown by the IR-spectrum, they contain hardly any triazine 
structures, but instead show the bands of the 
##STR8## 
group at 4.4 .mu. and the band of the 
##STR9## 
group at 5.9 .mu.. 
The prepolymers may be converted into high molecular weight polymers (B) of 
triazine structure by heating to about 150.degree.-350.degree. C, 
preferably to 150.degree. - 300.degree. C, optionally in solution and 
optionally in the presence of a catalyst or catalyst mixture. The end 
products are substantially insoluble in solvents and are infusible. As 
shown by the infrared spectrum, the polymer does not contain any other 
crosslinking principles apart from triazine structures. The formation of 
the high molecular weight polymers with triazine structures indicates that 
the cyanic acid ester and cyanamide groups have participated equally in 
formation of the triazine ring. 
Catalysts suitable for use in the production of the prepolymer and high 
molecular weight end polymer with triazine structures include acids, 
bases, salts, nitrogen and phosphorus compounds, for example Lewis acids 
such as AlCl.sub.3, BF.sub.3, FeCl.sub.3, TiCl.sub.4, ZnCl.sub.2 or 
SnCl.sub.4, proton acids such as HCl or H.sub.3 PO.sub.4 ; aromatic 
hydroxy compounds such as phenol, p-nitrophenol, pyrocatechol or dihydroxy 
naphthalene; sodium hydroxide, sodium methylate, sodium phenolate, 
trimethyl amine, triethyl amine, tributyl amine, 
diazabicyclo-(2,2,2)-octane, quinoline, isoquinoline 
tetrahydroisoquinoline, tetraethyl ammonium chloride, pyridine-N-oxide, 
tributyl phosphine, phospholine-.DELTA..sup.3 -1-oxa-1-phenyl, zinc 
octoate, tin octoate, zinc naphthenate, and mixtures thereof. 
The catalysts may be used in quantities of from 0.001% by weight to 10% by 
weight, based on the prepolymer, or if desired in even larger quantities. 
The prepolymers may be used in solution in inert solvents, such as acetone, 
benzene, xylene, chlorobenzene, ethyl acetate, tetrahydrofuran, dibutyl 
ether or dimethyl formamide, or in powder form, for the production of 
coatings on substrates such as metals, ceramics, glass, earthenware, etc., 
or in solution in organic solvents as impregnating lacquers or laminating 
resins. If desired, the prepolymers may be combined with fillers, 
pigments, glass fibres, metal fibres and glass cloths and used for the 
production of shaped articles or laminates. Yellow to brown, transparent, 
extremely hard and temperature-resistant end products are obtained after 
hardening. 
The polytriazines may even be formed in a single stage without isolating 
the prepolymers.

The percentages and parts quoted in the following Examples relate to 
weight, unless otherwise indicated. 
EXAMPLE 1 
28.6 g (0.1 mol) of benzene-di-(sulphonylcyanamide)-1,3 and 27.8 g (0.1 
mol) of bis-2,2-(4-cyanatophenyl)propane are heated for 3 hours to 
70.degree. C in 200 ml of isopropanol. A polymeric 
N-sulphonyl-N-cyanoisourea ether with the characteristic IR-bands at 4.4 
.mu. 
##STR10## 
and 5.9 .mu. 
##STR11## 
is obtained in a quantitative yield following removal of the solvent. 
15 g of the polymeric N-cyanoisourea ether are heated under nitrogen for 7 
hours to 280.degree.-300.degree. C. A brown, very hard polymer with the 
IR-bands characteristic of the s- triazine ring at 6.4 and 7.25 .mu. is 
obtained after cooling. The bands typical of the prepolymer at 4.4 .mu. 
and 5.9 .mu. are no longer present in the reaction product. 
EXAMPLE 2 
20 g (0.07 mol) of benzene-di-(sulphonylcyanamide)-1,3 and 50 g (0.18 mol) 
of bis-2,2-(4-cyanatophenyl)propane are boiled under reflux for 4 hours in 
300 ml of toluene. A polymeric N-cyanoisourea ether containing cyanic acid 
ester is obtained in a quantitative yield following removal of the 
solvent. (IR-spectrum, N--C.tbd.N at 4.4 .mu., O--C.tbd.N at 4.5 .mu., &lt; C 
= NH at 5.9 .mu.). Hardening of this wax-like prepolymer takes place over 
a period of 5 hours at 180.degree.-200.degree. C in the presence of 0.1 % 
of zinc octoate. A yellow coloured extremely hard polytriazine is obtained 
(s-triazine band in the IR-spectrum at 6.4 .mu. and 7.25 .mu.). 
EXAMPLE 3 
36.2 g (0.1 mol) of diphenyl-di-(sulphonylcyanamide)-4,4' and 16 g (0.1 
mol) of resorcinol dicyanate are boiled under reflux for 3 hours in 200 ml 
of methyl ethyl ketone. A polymeric N-cyanoisourea ether is obtained in a 
quantitative yield following removal of the solvent. (IR-spectrum: 
##STR12## 
at 4.4 .mu., 
##STR13## 
at 5.9 .mu.). Hardening of this prepolymer into a polytriazine takes place 
over a period of 4 hours at 180.degree. C following the addition of 0.2% 
of pyrocatechol and 0.2% of diaza-bicyclo-(2,2,2)-octane. 
EXAMPLE 4 
37.8 g (0.1 mol) of diphenyl ether-di-(sulphonylcyanamide)-4,4' and 23.6 g 
(0.1 mol) of 1,4-dicyanatodiphenyl are boiled under reflux for 3 hours in 
250 ml of dichloroethane. A polymeric N-cyano-isourea ether having 
characteristic IR-bands at 4.4 .mu. and 5.9 .mu. is obtained following 
removal of the solvent. Hardening into a brown-coloured, extremely hard 
polytriazine takes place over a period of 3 hours at 170.degree. C in the 
presence of 0.1% of zinc chloride. 
EXAMPLE 5 
50 g (0.1175 mol) of diphenyl sulphone-di-(sulphonyl cyanamide)-3,3' and 40 
g (0.1333 mol) of 1,4-dicyanato diphenyl sulphone are boiled under reflux 
for 4 hours in 300 ml of isopropanol. A prepolymer having the IR-bands at 
4.4 .mu. (--N--C.tbd.N), 4.5 .mu. (--O--C.tbd.N) and 5.9 .mu. 
##STR14## 
is obtained in a quantitative yield following removal of the solvent. 
Hardening into an extremely hard polytriazine takes place over a period of 
4 hours at 200.degree. C in the presence of 0.2% of zinc octoate. 
EXAMPLE 6 
33.6 g (0.1 mol) of naphthaline-di-(sulphonylcyanamide)-1,5 and 33.4 g (0.1 
mol) of bis-2,2-(3,5-dimethyl-4-cyanatophenyl)-propane are boiled under 
reflux for 3 hours in 250 ml of isopropanol. A polymeric N-cyanoisourea 
ether (IR: band at 4.4 .mu. 
##STR15## 
at 5.9 .mu. 
##STR16## 
is obtained in a quantitative yield following removal of the solvent. 
Hardening into an extremely hard polytriazine takes place over a period of 
5 hours at 160.degree. C in the presence of 0.1 % of tin tetrachloride. 
EXAMPLE 7 
33.6 g (0.1 mol) of naphthalene-di-(sulphonylcyanamide)-2,6 and 21.0 g (0.1 
mol) of 1,5-dicyanatonaphthalene are boiled under reflux for 2.5 hours in 
dichloropropane. A polymeric N-cyano-isourea ether (IR-spectrum: 
##STR17## 
at 4.4 .mu., 
##STR18## 
at 5.9 .mu.) is obtained following removal of the solvent. Hardening into 
an extremely hard, brown-coloured polytriazine takes place over a period 
of 4 hours at 200.degree. C in the presence of 0.1% of tin octoate. 
EXAMPLE 8 
28.6 g (0.1 mol) of benzene-di-(sulphonylcyanamide)-1,3 and 13.3 g (0.066 
mol) of 1,3,5-tricyanatobenzene are boiled under reflux for 3 hours in 150 
ml of isopropanol. A polymeric N-cyano-isourea ether is obtained in a 
quantitative yield following removal of the solvent. (IR-spectrum: 
##STR19## 
at 4.4 .mu., 
##STR20## 
at 5.9 .mu.). Hardening of this prepolymer to form the extremely hard, 
brittle polytriazine takes place over a period of 5 hours at 210.degree. C 
in the presence of 0.2 % by weight of zinc octoate.