CS254698B1 - 4- (2,3-epoxyprnpoxy) -2,2,6,6-tetramethylpiperidine and its preparation - Google Patents

Abstract

The invention relates to 4-(2,3-epoxypropoxy)-2,- 2,8,6-tetramethylpiperidine of formula I and to a method for its preparation, which consists in reacting 2,2,6,6-tetramethyl-4-hydroxypiperidine of formula I with epichlorohydrin under intensive stirring in a heterophase system, whereby one phase is formed by an aqueous solution of an alkali hydroxide and the second phase is formed by an organic solvent immiscible with the aqueous phase in the presence of an onium salt type catalyst in the temperature range of 10 to 100 °C. The compound of formula I is used as a light stabilizer for polymers and for the preparation of polymer light stabilizers by polyaddition and copolyaddition reactions, for the preparation of polyethers, copolyethers, polyesters and copolyesters, or enables the attachment of the stabilizer molecule to suitable groups on the polymer chain.

Description

The invention relates to 4- (2,3-epoxypropoxy) -2,2,6,6-tetramethylpiperidine and a method thereof. of preparation.

Sterically shielded amines are currently among the most effective light stabilizers for polymers [F. E. Karrer, Makromol. Chem. 181, 595 (1980), F. Gugumus, Developments in Polymer Stabilization-1, ed. G. Scott, Applied Science Publishers, London, 1979, Chap. 8. J. J. Usilton, A. R. Patel., Amer. Chem. Soc. Polym. Prep., 18 (1), 393 (1977). They are various derivatives of 2,2,6,6-tetramethylpiperidine, 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 interaction of light and oxygen with polymers. A disadvantage of this class of light stabilizers is the high volatility and extractability of low molecular weight derivatives from polymers. The substance of the invention contains a reactive epoxy group in its molecule. The presence of this group in the light stabilizer molecule enables the preparation of high molecular weight light stabilizers by polyaddition and copolyaddition reactions, the preparation of polyethers, copolyethers, polyesters and copolyesters, as well as the attachment of the light stabilizer molecule to suitable groups on the polymer chain. This. the compound has not been previously described in the literature.

The present invention provides 4- (2,3-epoxypropoxy) -2- [beta] -tetramethylpiperidine of formula I.

between 5 to 70% and of the species The phase forms an organic solvent not mixed with the aqueous phase, such as benzene, toluene or xylenes, in the presence of an onium salt type catalyst such as tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylaimonium hydrogen sulphate or tetrabutylphosphonate used in an amount of 1 to 10 mol% for the amount of compound II in the temperature range of 10 to 100 ^° C.

Example 1

7.85 g (0.05 mol) of 2,2,6,6-tetramethyl-4-hydroxypiperidine, 1.61 g (0.005 mol of tetrabutylammonium bromide), 23 g (0.25 mol) of epichlorohydrin, 20 ml of benzene and 20 ml of 50% The organic layer was separated, washed with water and brine, and dried over anhydrous sodium sulfate. The solvent and excess epichlorohydrin were distilled off in a vacuum evaporator to give a yellowish liquid which was vacuum dried. distilled.

A colorless liquid fraction is collected over a temperature range of 95-105 ^° C at 0.2 kPa. Yield: 6.0 g of pure product, i.e. 56.3% of theory.

Elemental analysis for:

C12H23NO2 calculated:

H, 10.87; N, 6.57.

C ΜC H ί v ,, J • y /

T ~ \ v / ^X O (II

The present invention further provides a process for the preparation of a compound of formula I, characterized in that 2,2,6,6-tetramethyl-4-hydroxypiperidine of formula II is found:

H, 10.47; N, 6.51.

¹ H, NMR spectrum (CDCl 3)

Δ (ppmj:

1.05 (s, --CH 3 ax, 6H),

1.08 (s, —CH 3 eq, 6H),

1.50 to 2.08 (m, --CH2 -, 4H), 2.42 to 2.80 fin,

2.88 to 3.30

The OH reacts with epichlorohydrin under vigorous stirring in a heterophasic system, one phase forming an aqueous solution of an alkaline hydroxide, preferably sodium hydroxide in a concentration range of 5 to 50% or potassium hydroxide in a concentration range of 3,35 to 4,00 (m, - CH2 - O). -, .dbd.CH - O--, 3H).

Example 2

7.85 g (0.05 mol) of 2,2,6,6-tetramethyl-4-hydroxy-roxypiperidine, 0.85 g (0.0025 mol) of tetrabutylammonium hydrogen sulphate, 11.5 g (0.125 mol) of epichlorohydrin, 20 ml toluene and 20 ml of a 30% aqueous potassium hydroxide solution are stirred vigorously at 50 DEG C. for 16 hours, and the reaction mixture is worked up as in Example 1. The yield is 6.8 g of pure product, i.e. 64% of theory.

Example 3

7.85 g (0.05 mol) of 2,2,6,6-tetramethyl-4-hydroxipiperidine, 0.34 g (0.001 mol) of tetrabutylphosphonium bromide, 5.55 g (0.06 mol) of epichlorohydrin, 10 ml of the mixture The xylenes having a distillation range of 137 to 140 ° C and 20 ml of a 60% aqueous potassium hydroxide solution are vigorously stirred at 100 ° C for 6 hours. After cooling, the reaction mixture was worked up as in the reaction

SUBJECT

Claims (5)

0.82 g (0.0025 mol) tetra-butylammonium hydrogen sulphate, 11.5; g (0.125 mol) of epichlorohydrin, 20 ml of toluene and 20 ml of a 30% aqueous potassium hydroxide solution are stirred vigorously at 50 DEG C. for 16 hours. The reaction mixture was worked up as in Example 1. Yield: 6.8 g of pure product, i.e. 64% of theory. Example 3 7.85 g (0.05 mol) of 2,2,6,6-tetramethyl-4-hydroxipiperidine, 0.34 g (0.001 mol) of tetrabutylphosphonium bromide, 5.55 g (0.06 mol) (ll) of epichlorohydrin, 10 ml of a xylene mixture of a 137- 140 ° C xylene range, and 20 ml of a 60% aqueous potassium hydroxide solution were vigorously stirred at 100 ° C for 6 hours. After cooling, the reaction mixture is treated as in SUBJECT 1. 4- (2,3-epoxypropoxy) -2,2,6,6-tetramethylpiperidine of the formula (I). with CM, - h J í f) 2. A process for the preparation of 4- (2,3-epoxypropoxy) -2,2,6,6-tetramethylpiperidine of the formula I according to claim 1, wherein the 2,2,6,6-tetra-methyl-4-hydroxypiperidine of the formula II EXAMPLE 1 Yield 7.2 g of pure product, i.e. 67.6% of theoretical yield. EXAMPLE 4,100 parts by weight of unstabilized polypropylene powder are impregnated in dichloromethane with 0.1% by weight of the theoretical product. 2,6-di-tert-butyl-4-methylphenol, 0.15 wt. of calcium stearate and 0.2 wt. of the compound of Example 1. After evaporation of the solvent, a 0.2 mm thick film was pressed from the mixture at a pressure of 20 MPa and a temperature of 190 ° C. 5 min. The thus prepared film is irradiated with a mercury discharge lamp with a power of 125 W at a distance of 7 cm from the source. The degradation of the polymer is monitored by developing a carbonyl band in infrared spectra. While the carbonyl index time of 0.2 for pure polypropylene was 220 hours, the stabilized polymer reached a value after 1800 hours. THE INVENTION reacts with epichlorohydrin under intensive mixing in a heterophasic system, forming one phase of the alkaline hydroxide solution in one phase and generating the phase phase organic solvent immiscible with the aqueous phase, in the presence of an auto salt type catalyst with a temperature range of 10 to 100 ° C. 3. A process according to claim 2, wherein sodium hydroxide is used as the alkali hydroxide in a concentration range of 5 to 50% or potassium hydroxide in a concentration range of 5 to 70%. 4. A process according to claim 2, wherein benzene, toluene or xylenes are used as the aqueous phase-immiscible organic solvent. 15. A process as claimed in claim 2, wherein the reaction catalyst used is a sodium salt such as tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium hydrogen sulfate or tetrabutylphosphonium bromide in an amount of 1 to 10 mol% based on the amount of compound 2.2. 6,6-tetramethyl-4-hydroxypiperidine. (i