CS226927B1 - Polyamides of sterically hindered piperazindione type on the basis of alpha-substituted propandionic acid - Google Patents

Description

The invention relates to sterically hindered piperazinedionic polyamides based on N-substituted propanedioic acid comprising in their chain a structural unit of the general formula

wherein Q is an alkylene chain having a carbon number of 2 to 6, n having a value in the range of 2 to 15 and a process for preparing them.

The process for the preparation of sterically hindered piperazinediones-type polyamides based on α-substituted propanedioic acid is based on ammonolysis of 2- [7,15-diazadispido (5,1,5,3) hexadecane-14,16-dione-, dimethyl or diethyl ester] 15-yl] propanedioic aliphatic diamines having 2 to 6 carbon atoms (1,2-diaminoethane, 1,6-diamino hexane) at a temperature ranging from 100 to 150 ° C in a dry hydrocarbon solvent (xylene, nitrobenzene in the presence of a basic catalyst, such as sodium methoxide, lithium amide, tetrapropyltitanate, etc.

Sterically hindered amines are high-efficiency light stabilizers of many types of polymers. However, the use of low molecular weight substances of this type has some limitations. Their main drawbacks are: high volatility, considerable migrability, high extractability and, last but not least, good absorbability into the cellular spaces of living organisms. The first three undesirable properties result in a gradual loss of the utility polymer with a concomitant protective effect, first at its heat treatment, then at longer storage and finally at its chemical cleaning or washing. The easy penetration of the cell walls of living organisms due to the considerable toxicity of the low molecular weight derivatives of sterically hindered amines excludes them from application in stabilization! polymer materials in the food industry, eventually in the field of medicine. The reduction or elimination of these disadvantageous properties presupposes the use of higher molecular weight, oligomeric or polymeric light stabilizers with satisfactory tolerability, or the binding of stabilizing struts to the chain of the useful polymer.

The polymeric light stabilizer of the piperazine type belonging to the group of sterically hindered amines of the present invention can serve to suppress or eliminate the mentioned shortcomings of the low molecular weight compounds of the type.

Example 1

A mixture of 1.0212 g (0.0025 mol) Lester diet of 2- ^[7,15-l diazadi spiro (5, l, 5,3) hexadecane-14,16-dien-L5-yl] propanol and dioic 0 2905 g (0.0025 mol) of 1,6-diaminohexane in 10 ml of dry xylene are heated to 110 ° C and 5 mol. % sodium methoxide. The mixture is further heated for 4 h at the same temperature, while the reaction ethanol is slowly distilled off. After the time has elapsed, the temperature is raised to 130-135 ° C and held for a further 6 h, thereby distilling off the remaining reaction ethanol. The solvent was distilled off in vacuo and the residue was subjected to high vacuum for 2 hours at (150 ° C.) The flask was then allowed to cool, dissolved in 25 ml of toluene and washed three times with a small amount of water. Evaporation of the solvent and exposure of the residue to high vacuum at 120 ° C yields a solid, lightly dustable polymer having a melting point of 94-103 ° C with an average molecular weight of 1030 (determined by VPO osmometer). ₂₅ H ₃₆ N4O4: Calculated:

C = 65.79%, H = 7.89%, N = 12.28%; found:

C = 66.23 H = 7.98%, N = 12.55%. Example 2

The procedure was as in Example 1 except that the reaction was carried out in the presence of 5 mol% lithium amide. After isolation, a solid, easy-to-powder, polymer having a melting point of 97-100 ° C with an average molecular weight of 1190 (determined by VPO osmometer) was obtained. Elemental analysis for C 5 H _{36 2} N4O4 Calculated:

C = 65.79%, H = 7.89%, N = 12.28%; found:

C = 66.41 θ / ο, H = 8.78 ° / θ, N = 12.45%.

Claims (3)

3 226927 silicone stabilizers with suitable compatibility, or binding stabilizing structures to the utility polymer chain. The piperazine-type polymeric light stabilizer belonging to the group of sterically hindered amines, which is the subject of the invention, can serve to suppress or eliminate said low molecular weight drawbacks of said type. Example 1 A mixture of 1.0212 g (0.0025 mol) of 2- [7,15-diazadilspiro (5,1,5,3) hexadecan-14,16-dione-15-yl] propanedioic acid diethyl ester and 0, 2905 g (0.0025 mol) of 1,6-diaminohexane in 10 ml of dry xylene were added. heating 110 ° C and adding 5 moles. % sodium methoxide. The mixture was further heated for 4 h at the same temperature, with the reaction ethanol slowly decanting. After time elapsed, the temperature was increased to 130-135 ° C and maintained for a further 6 hours to distill off the remaining reaction ethanol. The solvent was distilled off under vacuum and the residue was subjected to high vacuum for 2 hours at 150 ° C. Then the contents of the flask are allowed to cool, dissolved in 25 ml of toluene and washed three times with small amounts of water. Finally, the toluene solution was dried over anhydrous sodium sulfate and purified with acute charcoal. Evaporating the solvent and exposing the residue to a high vacuum at 120 ° C yields a solid, readily dustable polymer with a melting point of 94-103 ° C with an average number molecular weight of 1030 (determined by VPO osmometer). 65.79%, H = 7.89%, N = 12.28%, Found: C = 66.23 H = 7.98%, N = 12.55%. that the reaction was carried out in the presence of 5 mol% lithium amide. After isolation, a solid, easy-to-dustable polymer was obtained with a melting point of 97-100 ° C with an average number-molecular weight of 1190 (determined by VPO osmometer). Analysis for ϋ ^ ΗββΝ ^, Calculated: C = 65.79% H = 7.89%, N = 12.28%, Found: C = 66.41 θ / ο, H = 8.78 °, N = 12.45%. OBJECT 1. Polyamides of the sterically hindered α-substituted propanedioic acid-based piperazinediones which contain repeating structural members of the general formula in the molecule wherein Q is an alkylene chain having a carbon number of from 2 to 6, and n is from 2 to 15. 2. A process for the preparation of polyamides of stearically hindered piperazinediones based on .alpha.-substituted propanedioic acid according to claim 1, characterized in that the dimethyl or diethyl 2- [7,15-diaza-dispiro (5,1 5,3) Hexadecane-14,16-dione-1-yl] -propanedioic acid is treated with aliphatic diamines with carbon numbers of 2 to 6, such as 1,2-diaminoethane, 1,6-diaminohexane. 3. Process according to claim 2, characterized in that the reaction is carried out in the presence of basic catalysts such as sodium methoxide, lithium amide, tetrapropyl titanium and the reaction is carried out at a temperature in the range of 100 DEG to 150 DEG C. in a dry carbon phase. hydrogen solvent, such as xylene, nitrobenzene.