CS231250B1 - Roly-ethylene-2- (2,2,6,6-tetramethyl-4-piperidylamino) butanedione and its preparation - Google Patents

Abstract

The invention relates to poly(ethylene-2-(2,2,6,6-tetramethyl-4-piperidylamino)butanedionate) and to methods of its preparation. The essence of the invention is poly{ethylene-2-(2,2,6,6-tetramethyl--4-piperidylamino)butanedionate of the formula I where a is 2 to 100. The essence of the invention is also a process for the preparation of the compound of the formula I, which is characterized in that the compound of the formula II given above is treated with the compound of the formula III given below in dimethylformamide, dimethyl sulfoxide or chloroform from the mixture 4 to 8 at a temperature of 60 to 80 °C. The invention has application in polymer chemistry for the preparation of polymeric light stabilizer of polymers.

Description

The invention relates to poly(ethylene-2-(2,2,6,6-tetramethyl-4-piperidylamino)butanedionate) and a process for its preparation.

Steric hindered amines are highly effective light stabilizers of polymers. They inhibit radical processes that occur during photooxidation of polymers. The disadvantage of low molecular weight compounds of this group is their considerable volatility and extractability.

The present invention eliminates the above disadvantages. The essence of the invention is poly {ethylene-2-(2,2,6,6-tetramethyl-4-piperidylamino)butanedionate of formula X

(I), where n is 2 to 100. The invention further provides a method for preparing a compound of formula I, which is characterized in that polyethylene maleate of formula II, C—CH=CH—C 'O-CH ₂ -CH ₂ -O-^Jn (II), where n is 2 to 100, is treated with 4-amino-2,2,6,6-tetramethylpiperidine of formula III nh ₂ ^h 3 ^c J > ^CH 3 ^H 3 ^C ^H ^CH 3 (III), in dimethylformamide, dimethylsulfoxide or chloroform with stirring for 4 to 8 hours at a temperature of 60 to 80 °C.

The advantage of the above-mentioned piperidine type with the disadvantages occurring in the invention is the preparation of a polymeric light stabilizer of polymers with an increased molecular weight, which significantly eliminates the aforementioned disadvantages of low-molecular compounds of this group.

Example 1

To a solution of 1.741 5 g (0.01 mol) of polyethylene maleate with an average number molecular weight of 3,200 in 25 ml of dimethylformamide or dimethyl sulfoxide at a temperature of about 20 °C, 1.552 6 g (0.0) mol) of 4-amino-2,2,6,6-tetramethylpiperidine is slowly added dropwise. The mixture is allowed to stir at a temperature of 80 °C for 8 h and the solvent is distilled off in vacuo. After cooling, 50 ml of petroleum ether is added to the greasy residue and this solidifies after standing for several hours with occasional stirring. The petroleum ether is decanted and the solid residue is dried at a temperature of 80 °C under high vacuum. A glassy, powdery polymer with a melting point in the range of 64 to 70°C and a number average molecular weight of 3,320 is obtained.

Elemental analysis for: ^C 1.5 ^H 26 ^N 2°4 calculated: 60.38% C, found: 60.07% C,

8.78% H, 9.39% N; 8.95% H, 9.21% N.

spectrum (chloroform) in

max = 900, 980, 1,080, 1,150, 1,250, 1,290, 1,330, 1,370, 1,440, 1,560., 1,630, 1,730, 2,960, 3,270 cm ¹

Example 2

The procedure is as in Example 1 except that the reaction is carried out in chloroform solution at reflux temperature. By working up as in Example 1, a polymer with a number average molecular weight of 3,400 is obtained.

Example 3

From 36 g of polypropylene powder, homogenization with 0.72 g of the compound according to Example 1 was prepared by mixing in a Brabender plastograph and subsequent pressing of a film with a thickness of 0.2 mm, which was irradiated in a rotary irradiation device with a Tesla RVV 125 W discharge lamp. The development of carbonyl groups in the unstabilized and stabilized film was monitored. While the unstabilized film reached a carbonyl index of 0.1 in 190 hours, the stabilized film reached the same degree of degradation in 950 hours.

The invention has application for the preparation of a polymeric light stabilizer for polymers.

Claims (2)

EXAMPLE 2 The procedure is as in Example 1 except that the reaction is carried out in solution in chloroform at a low flow temperature. Processing as in Example 1 yields a polyether having an average molecular weight of 3,400. EXAMPLE 3 From a 36 g polypropylene powder, homogenization with 0.72 g of the compound of Example 1 was carried out by mixing in a Brabender plastograph and then pressing a 0 gauge film. 2 mm, which were irradiated in the irradiation rota- tion apparatus by a Tesla RVV 125 W lamp. It monitored the development of carbonyl groups in the unstabilized and stabilized film. While the unstabilized foil reached a carbonyl index of 0.1 for 190 hours, the stabilized boiling point reached a thin degree of degradation at 950 hours. The invention has utility in the preparation of a polymeric polymer light stabilizer. P R E D E T OF THE INVENTION 1. Foly {ethylene-2- (2,2,6, t-tetramethyl-4-piperidylamino) butanedione wherein n is 2 to 100. 2. A process for the preparation of compound (I) according to claim 1, characterized in that the polyethylene maleate of formula (II), G-CH = CH-CH2-O-CH2-CH2-O- (II), where n is 2 to 100, with 4-aaino-2,2,6,6-tetraaethylpiperidine of formula III nh 2 H, C h 3c CH, CH, (III), in dinethylformamide, dimethylsulfoxide or chloroform under stirring for 4 to 8 hours at 60 to 80 ° C.