CS254697B1 - 4,4-bis (2-chloroethoxy) -2,2,6,6-tetramethylpiperidine and its preparation - Google Patents

Abstract

The solution relates to 4,4-bis(2-chloroethoxy}-2,- 2,6,6-tetramethylpiperidine of formula I and a method for its preparation, which consists in reacting 2,2,6,6-tetramethyl-4-oxopiperidine of formula II with 2-chloroethanol at the reflux temperature of a hydrocarbon solvent that forms an azeotropic mixture with water, such as benzene, toluene or xylenes, in the presence of an acidic catalyst, such as 4-toluenesulphonic acid. The compound of formula I has use as a light stabilizer for polymers and for the preparation of polymer light stabilizers by polycondensation reactions, the preparation of polyethers, polythioethers, polyesters or polycarbonates.

Description

The invention relates to 4,4-bis (2-chloroethoxy) -2,2,6,6-tetramethylpiperidine and to a process for its preparation.

Serially shielded amines are currently among the most effective light stabilizers for polymers [F. E. Karrer, Makromol. Chem., 181, 595 (1980). J. Usilton, A.R. Patel, Amer. Chem. Soc. Polym. Prep., 18 (1), 393 (1977), by F. Gugumus, Developments in Polymer Stabilisatton-1, ed. G. Scott, Applied Science Publishers, London, 1979, Chapter 8], These are various derivatives of 2,2,6,6-tetraalkylpiperidine, 1,2,2,6,6-pentaalkylpiperidine,

2,2,6,6-tetraalkylpiperazine or 7,15-diazadispiro [5,1,5,3] hexadecane. These compounds inhibit undesirable degradation processes that occur in the light and oxygen immersion with polymerization. The disadvantage of this group of light stabilizers is the high volatility and low-molecular-weight extractability of low molecular weight polymers. The substance of the invention contains two functionally chloroalkyl groups in its molecule. The preparation of this compound increases the molecular weight of the stabilizer, reducing the extractability and volatility of the polymer stabilizer. The presence of functional chloroalkyl groups simultaneously allows the preparation of polymeric stabilizers by polycondensation reactions, the preparation of polyethers, polythioethers, polyesters and polycarbonates. The compound object of the invention is not yet described in the literature.

The present invention provides 4,4-bis (2-chloroethoxy) -2,2,6,6-tetramethylpiperidine of formula I.

αχ

O ~ C H C I 7 t.,? ' / \ <£

CH \ CHg a,

Example 1

15.5 g (0.1 mol) of 2,2,6,6-tetramethyl-4-oxopiperidine, 20 g (0.105 mol) of 4-toluenesulfonic acid χ H2O are placed in a flask equipped with an azeotropic separation of water and bad condensers. and 200 ml benzene. The reaction mixture was heated at reflux for 1 hour while separating the crystalline water from the acid and the moisture from the system. At the same time, the acid salt of the piperidine derivative is formed. 17.7 g (0.22 mol) of 2-chloroethanol are then added and the reaction mixture is further refluxed until the theoretical amount of water is precipitated in the azeotrope. The reaction mixture was cooled and poured into cold 20% aqueous sodium hydroxide solution and shaken. The organic layer was separated, washed with water and brine and dried over anhydrous sodium sulfate. The solvent and excess 2-chloroethanol were distilled off to give 28 g (93.9% of theory) of the crude product as a yellow liquid. The crude product is purified by distillation under reduced pressure, collecting a fraction having a boiling point of 127-135 ° C at 0.17 kPa.

Elemental analysis for:

1C13H25Cl2NO2 calculated:

% C, 52.35;% H, 8.45;% N, 4.70.

C, 151.86; H, 8.31; N, 4.56.

NMR Spectrum (CDCl3)

S (ppm):

1.15 (s, —CH3, 12H).

1.58 (s, --CH2 -, 4H), 3.62 (t, --CH2 --C1, 4H), 3.65 (t, --CH2 --O--, 4H).

Example 2

The present invention further provides a process for the preparation of a compound of formula I wherein 2,2,6,6-tetramethyl-4-oxopiperidine of formula II is reacted with 2-chloroethanol at a low flow temperature of a hydrocarbon solvent which forms an azeotropic mixture with water, such as is, for example, benzene, toluene or xylenes, in the presence of an acid catalyst such as 4-toluenesulfonic acid,

The procedure was as in Example 1 except that the solvent used was a mixture of xylenes having a boiling range of 137-140 ° C. Yield: 28.9 g (97% of theory) of the crude product.

Example 3

100 parts by weight of unstabilized powdered polypropylene are impregnated in dichloromethane with 0.1 upper parts of 2,6-di-tert-butyl-4-methylphenol, 0.15 wt. % of calcium stearate and 0.2 wt. After evaporation of the solvent, 0.2 mm thick sheets are pressed from the mixture at 20 MPa at 190 ° C for 5 minutes. The films thus prepared are irradiated with a 125 W mercury lamp at a distance of 7 cm from the source. The degradation of the polymer is monitored by the development of the carbonyl-6-bilized polymer until it reaches this value after 1600 hours.

in the infrared spectra. While the time of reaching the carbonyl index of 0.2 for pure polypropylene is 220 hours,

Claims (2)

254596 5 position in infrared spectra. While the carbonyl index of 0.2 µl of pure polypropylene is 220 hours, the three-bilaylated polymer reaches this value after 1600 hours. SUBJECT 1. 4,4-Bis (2-chloroethoxy) -2,2,6,6-tetramethylpiperidine of Formula I. 2. A process for preparing 4,4-bis (2-chloroethoxy) -2,2,6,6-tetramethylpiperidine of Formula I, wherein the 2,2,6,6-tetra-methyl-4-oxopiperidine of formula II C'H, GH · 1) W-H X-θ reacts with 2-chloroethanol at the temperature of the flux of the hydrocarbon solvent, which forms an azeotropic mixture with water, such as benzene, toluene or xylenes, under catalysis 4-toluenesulfonic acid until the theoretical amount of reaction water is precipitated.