CS225480B1 - Polymeric light stability agent and its manufacture - Google Patents

Description

The present invention relates to a polymeric light stabilizer which comprises: polyesters of 15- [7,15-diazadispiro [5,1,5,3] hexadecyl] methylenebutanedioic acid, 5'-diols.

Sterically hindered amines are a modern class of plastic light stabilizers, especially polyolefins and especially polypropylene. Their use represents a qualitative step to improve the aging resistance of polyolefins. A certain disadvantage of low-molecular-weight substances of this class is their washability.

This disadvantage is substantially eliminated by the present invention, which is based on a polymeric light stabilizer representing polyesters of 15- / 7,15-diazadispirojic acid. 1,5,3] hexadecyl / methylenebutanedio [1,4] 3-diols of general formula I - -

-0C-CH ₂ -CH-C00- / CH ₂ -CH ₂ / _m -0-

wherein m is 1.2 and n is 3 to 20.

The invention furthermore relates to a process for the preparation of these ester esters, characterized in that for dialkyl esters of 15- [7,15-diazadispiro [eta] < 5 >

ROOC-CH-CHO-COOR

wherein R is methyl, ethyl and propyl are treated with the ε, β-diols of formula III:

HO- / CH ₂ -CH ₂ / _m -OH (III) wherein m is 1 and 2 hours at 110 ° C, 10 hours at 140 ° C in the presence of lithium amide or tetrapropylortotitanate while bubbling nitrogen. Finally, the reaction mixture is heated at 160 ° C under 18 Pa for 2 hours.

An advantage of the present compounds is their increased molecular weight, which contributes to a significant reduction in their scrubbing ability from the stabilized polymer.

Example 1

A mixture of 1 mole of 15- [7,15-diazadispiro [5,1,5,33-hexadecyl] -methylenebutanedioic acid dimethyl ester, 1.2 mole of ethylene glycol, g of lithium amide and 2.5 g of 2,2-methylene-hJs- / 4 of methyl-6-tert-butylphenol] in 1200 mL of xylene was heated ############### Then xylene was distilled off from the reaction mixture and further heated at 160 ° C for 2 hours at 18 Pa. The toluene solution of the reaction mixture was washed with water, toluene was distilled off and the product was dried in a vacuum oven. A rye powder was obtained in a yield of 81% with an average molecular weight of 2,250 (osmometric determination). By changing the reaction temperature and time, polyesters with average molecular weights of 900 and 1600 were prepared.

The analysis of the / ^ 34 ^ 21 ^ 2 N 4 O MW / 378.51 / _n

calculated

found

% C, 66.64;% H, 9.05;% N, 7.40%

Example 2

A mixture of 1 mole of diethyl 15- [7,15-diazadispiro [5,1,5,3] hexadecyl] methylenebutanedioic acid, 1.2 mole of 1,4-butanediol, g of tetrapropylortotitanate and 2.5 g of 2,2'-methylene- bis- (4-methyl-6-tert-butylphenol) in 1200 ml of xylene was heated under nitrogen bubbling at 120 ° C for 2 hours and 8 hours at 150 ° C. After distilling off the xylene, the mixture was heated at 160 ° C under pressure for 2 hours

Pa. The toluene solution of the reaction mixture was washed with water, toluene was distilled off and the product was dried in a vacuum oven. A pale yellow powder was obtained in a yield of 75% with an average molecular weight of 2000.

Analysis for (? 23? 38? 2?) MW (406.57).

calculated

found

67.95% C 67.10% C

H, 9.42; H, 9.13

N, 6.89

Example 3

0.1 wt. (2,2'-Methylene-bis (4-methyl-6-tert-butylphenol)) antioxidant, 0.15 wt. % calcium stearate and 0.2 wt. The light stabilizer prepared according to Examples 1 and 2. The mixture was homogenized in a plastograph at 200 ° C for 5 minutes. Foils of 0.18 mm thickness are pressed from the mixture and irradiated with a 125 W mercury lamp. Control films are prepared in the same manner, except that no light stabilizer is added. The increase in carbonyl groups as a function of the irradiation time is a measure of the polymer degradation due to UV radiation. The growth of carbonyl groups is monitored by IR spectra. The film without the light stabilizer reached an increase in carbonyl index Δ Αθθ = 0.3 after 300 hours. The film containing the light stabilizer prepared in Example 1, (M = 1, 600) reached Δ Αθθ = 0.3 after 600 hours and the film containing the light stabilizer prepared according to Example 2 reached Δ Αηθ = 0.3 after 620 hours . The film containing the commercial poly-1,4- (2,2,6,6-tetramethylpiperidinyloxy) succinate stabilizer reached ΔA _C q = 0.3 after 670 hours.

Said compounds can be used as light stabilizers with reduced washability, especially in polyolefins.

Claims (3)

OBJECT OF THE INVENTION CLAIMS 1. Polymeric light stabilizer representing a polyester of 15- / 7,15-diazadispirofX, 1,5,3] hexadecyl / methylenebutanedioic acid with vC, lithium diols of the general formula ca I -OC-GH ₂ -CH-COO- / CH ₂ -CH ₂ / _m -O- wherein m is 1 and 2 and n is 3 to 20 2. A process for the preparation of stabilizers of the formula I as claimed in claim 1, characterized in that for the dialkyl 15- / 7,15-diazadispino [5,1,5,3] hexadecyl / methylenebutanedioic acid of the formula II: R00C-CH _o -CH-COCR i wherein R is methyl, ethyl and propyl are treated with 6-diols of formula III H _{2 -} (CH ₂₎ -CH ₂ / _m -OH (III) wherein m is 1 and 2 3 hours at 110 ° C, 10 hours at 140 ° C under nitrogen bubbling in the presence of lithium amide or tetrapropyl ortho titanate and finally 2 hours at 160 ° C and 18 Pa.