DE2022491A1 - Polymers of n-dicyanamides of dicarboxylic acids - obtained - by heating for several hours - Google Patents

Abstract

Light-fast, brittle to elastic resins, suitable for films, coatings (from solns.) or adhesives obtained by heating for 1 - 6 hr. (pref. 3 - 5 hr.) at 80 - 200 degrees C (pref. 100 - 160 degrees C) N,N'-dicyanodicarboxylic diamides in absence of O2 either as the melt or as a soln. in OH or NH2-free solvents, such as xylene, sulpholan, etc.

Description

"Process for the preparation of polymers from N-cyanamides of dicarboxylic acids" The invention relates to a process for the production of polyadducts from N-cyanamides, whereby linear and cyclic structures are formed.

It was an object of the present invention to provide a method for production of novel polyaddition products to find advantages in various respects and occur as clear, depending on the starting material, brittle to elastic resins can and due to their variable properties in technology of the most diverse Can find application.

The new polyad addition products are prepared by N, N'-Dicyandicarbonsäurediamide heated to temperatures between about 80 and 200 ° C. N, N'-dicarboxylic acid diamides are preferably heated for 1 to 6 hours, in particular for 3 to 5 hours, to 100 to 16 ° C.

The reaction according to the invention proceeds with the release of heat and can both in the melt and in no OH or amino groups Solvent can be made. Such solvents are, for example, high boiling points alphatic or aromatic hydrocarbons such as toluene, xylene, cumene, tetrahydronaphtanol, Sulfolane or the like. More. Especially in the case of N, N'-dicyanamides of aliphatic dicarboxylic acids is up to 10 carbon atoms the heat of the polyaddition so large that the reaction should be carried out in solvents.

The reaction is expediently carried out in the absence of oxygen, i. made under a nitrogen or noble gas atmosphere. It is also possible especially when using low-boiling solvents, reactions take place below To perform printing.

In the reaction according to the invention, the N-cyanamide groups partially react analogously to the formation of dicyandiamide from cyanamide in the form of a linear polyaddition, for example according to the following scheme: In addition, triazine rings can be formed in the polyaddition with cyclization - N C-HN CR »C - HN-C> -NH-CRG-NH- - N 0 0 N 0 0 NC-NH-CRC-NH-C-N - + (I II OO NH C0 a R. C: 0 1 NH C. (R r alkylene radical) NN II The detection of the triazine structures can easily be done by hydrolytic degradation of the polyadduct.

Depending on the degree of hydrolysis, different aminotriazines and Cyanuric acid. In general, about 40 to 70% polyadducts with triazine rings should be form.

The N, N'-dicyandicarboxylic acid diamides are produced in an known way by reacting the dicarboxylic acid chlorides or dicarboxylic acid esters with cyanamide. This reaction is expedient in the presence of alkaline agents Funds made. Here comes, for example, sodium alcoholate such as sodium methylate, Sodium ethylate, potassium isopropylate or sodium carbonate, sodium hydroxide, calcium oxide or the like - in question.

For practical reasons, it is expedient to use Dicarboxylic acid, which have about 6 to 36 carbon atoms. Usable acids are for example adipic acid, sebacic acid or dimerized fatty acids.

Also other than the mentioned dicarboxylic acids with a between 10 and 36 carbon atoms are in principle usable, but technically only hard to access.

The resins according to the invention fall depending on the type and purity of the starting material from the melt as clear, brittle to elastic yellow to brown products. If the polycondensation is carried out in solvents, the products fall as a yellow to brown powder. The polyadducts are thermoplastic and e.g. processable directly from the melt to form a film. You can also use solvents dissolved can be used as a coating agent. They are also available as hot melt adhesives or fluidized bed powder usable. They are characterized by good lightfastness the end. When assembling adhesives or coating compounds, ground in a well-known way other auxiliaries used such as plasticizers, Fillers, dyes, antioxidants and the like. More.

Examples Preparation of N, N'-Dicyandicarbonsäurediamiden zu ether A solution of 46 g of sodium in 1,000 cc of ethanol was added to 84 g of cyanamide. Under 174 g of dimethyl adipate were added with stirring. After 6 hours, the 800 C suctioned off the formed sodium salt in the cold, dissolved in water and with Hydrochloric acid adjusted to a pH of 2 to 3, the free N, N'-dicyanadipinediamide was obtained in the form of colorless crystals.

Yield: 85% of theory

1180 0 The substance is soluble in hot water, in cold methanol, Ethanol, acetone, dimethylformamide and acetonitrile, insoluble in chloroform, ether, Benzene and gasoline.

Instead of dimethyl adipate, 230 g of dimethyl sebacate were used used under otherwise identical reaction conditions, it was practically the the corresponding N, N'-dicyansebazine diamide is obtained in the same yield.

It had an F 112-114 ° C.

Instead of dimethyl adipate, the equimolar amount was used Dimethyl ester of dimer fatty acid (average C36) was used in about the same yield that corresponding to N, N'-dyncyandiamide of dimerized fatty acid obtain.

Example 1: 20 g of N, N'-dicyansebazine diamide were added under nitrogen and moisture exclusion within 30 minutes until the melting point (112 - 114 ° C) heated. The clearly exothermic reaction that began during the melting process was tempered by water cooling. The mixture was left at 1200 ° C. for one hour with stirring. The product solidified to a deep yellow, clear, hard resin on cooling pulverizable. As a powder or straight from the melt, it was too clear, hard Films can be processed without surface tack. The resin (F 110 - 1200 C) reacts weakly acidic, is soluble in hot dimethylformamide and acetic acid, partially soluble in hot methanol, ethanol and dioxane and insoluble in water, acetone and Benzene.

Example 2: 15 g of N, N'-dicyanadipinediamide were in 30 ml of sulfolane dissolved in the warmth. The mixture was heated to 900 ° C. in the course of 30 minutes and then 3 hours leave at this temperature.

After cooling, a yellowish powder (F 105 - 1150 C). This turned into one with initially strong bubbles Melt the hard3 brittle film. The solubility behavior corresponds to that of according to example 1 shown product.

Example 3: 50 g of N, N'-dicyandimer fatty acid diamide were added for 3 hours annealed at 11400 C. The initially pourable liquid became increasingly viscous and solidified into a yellow, clear, heat-castable resin. Poured from it Films still showed some surface tack (F 50 -650 c).

Claims (4)

Pat ent claims 1) Process for the production of polyadducts, characterized in that that N, N'-Dicyancarbonsäurediamide to a temperature between 80 and 2000 C. heated. 2) Method according to claim 13, characterized in that one N, N'-dicarboxylic acid aniides for 1 to 6 hours, in particular for 3 to 5 hours, to 100 to 1600 C heated. 3) Process according to claim 1 and 2, characterized in that one the reaction is carried out in the absence of oxygen. 4) Process according to claim 1 to 3, characterized in that one carries out the reaction in an inert solvent.