Compounds and liquid-crystalline medium

Abstract

Compounds of formula I, ##STR00001##
in which X.sup.1, X.sup.2, Sp, and R are as defined herein, are suitable for use in liquid-crystal media, such as liquid-crystal media used in liquid-crystal displays.

Claims

1. A medium comprising one or more compounds of formula I in a concentration in the range from 1 ppm to 5,000 ppm, ##STR00335## in which X.sup.1 is O, (CO)O, O(CO), O(CO)O, NH, or NH(CO), X.sup.2 is O, (CO)O, O(CO), O(CO)O, or NH(CO), Sp denotes straight-chain alkyl having 1 to 20 C atoms, also cycloalkyl, cycloalkylalkyl or alkylcycloalkyl, where one or more CH.sub.2 groups in all these groups may each be replaced by O in such a way that no two O atoms in the molecule are connected directly to one another, and R denotes straight-chain or branched alkyl having 1 to 10 C atoms, also cycloalkyl, cycloalkylalkyl or alkylcycloalkyl, where one or more CH.sub.2 groups in all these groups may each be replaced by O in such a way that no two O atoms in the molecule are connected directly to one another.

2. The medium according to claim 1, wherein said one or more compounds of formula I are selected from compounds of formulae IA to IE, ##STR00336## in which X.sup.1, X.sup.2, and Sp have one of the meanings indicated in claim 1.

3. The medium according to claim 1, wherein said one or more compounds of formula I are selected from the compounds of formulae IA-1 to IE-1 and IA-2 to IE-2, ##STR00337## ##STR00338## in which Sp has one of the meanings indicated in claim 1.

4. The medium according to claim 1, further comprising one or more compounds of formulae II and/or III, ##STR00339## in which A denotes 1,4-phenylene or trans-1,4-cyclohexylene, a is 0 or 1, R.sup.3 denotes alkenyl having 2 to 9 C atoms, and R.sup.4 denotes an alkyl or alkoxy radical having 1 to 15 C atoms, where, in addition, one or more CH.sub.2 groups in these radicals may each be replaced, independently of one another, by CC, CF.sub.2O, CHCH, ##STR00340## O, COO or OCO in such a way that O atoms are not linked directly to one another, and in which, in addition, one or more H atoms may each be replaced by halogen.

5. The medium according to claim 1, further comprising one or more compounds of formulae D1, D2, D3, D4 and/or D5, ##STR00341## in which R.sup.0 denotes an alkyl or alkoxy radical having 1 to 15 C atoms, where, in addition, one or more CH.sub.2 groups in these radicals may each be replaced, independently of one another, by CC, CF.sub.2O, CHCH, ##STR00342## O, COO or OCO in such a way that O atoms are not linked directly to one another, and in which, in addition, one or more H atoms may each be replaced by halogen, X.sup.0 denotes F, Cl, a mono- or polyfluorinated alkyl or alkoxy radical having 1 to 6 C atoms, a mono- or polyfluorinated alkenyl or alkenyloxy radical having 2 to 6 C atoms, and Y.sup.1-2 each, independently of one another, denote H or F.

6. The medium according to claim 1, further comprising one or more compounds of formulae Y-1, Y-2, Y-3 and/or Y-4, ##STR00343## in which R.sup.2A denotes H, an alkyl or alkoxy radical having 1 to 15 C atoms, where, in addition, one or more CH.sub.2 groups in these radicals may each be replaced, independently of one another, by C, CF.sub.2O, CHCH, ##STR00344## O, COO or OCO in such a way that O atoms are not linked directly to one another, and in which, in addition, one or more H atoms may each be replaced by halogen, L.sup.1 and L.sup.2 each, independently of one another, denote F, Cl, CF.sub.3 or CHF.sub.2, Z.sup.2 and Z.sup.2 each, independently of one another, denote a single bond, CH.sub.2CH.sub.2, CHCH, CF.sub.2O, OCF.sub.2, CH.sub.2O, OCH.sub.2, COO, OCO, C.sub.2F.sub.4, CFCF or CHCHCH.sub.2O, p denotes 0, 1 or 2, q denotes 0 or 1, (O)C.sub.vH.sub.2v+1 denotes OC.sub.vH.sub.2v+1 or C.sub.vH.sub.2+1, and v denotes 1 to 6.

7. The medium according to claim 1, wherein said medium further comprises a compound of formula IIa-1 ##STR00345##

8. The medium according to claim 1, further comprising one or more polymerizable compounds.

9. A process for the preparation of a medium according to claim 1, comprising: mixing one or more compounds of formula I with at least one further mesogenic compound and optionally with one or more additive(s) and/or one or more polymerizable compounds.

10. A method of generating an electro-optical effect comprising applying a voltage across a medium according to claim 1.

11. An electro-optical liquid-crystal display containing a medium according to claim 1.

12. The medium according to claim 4, wherein R.sup.4 denotes alkyl having 1 to 12 C atoms or alkenyl having 2 to 9 C atoms.

13. The medium according to claim 1, wherein X.sup.1 and X.sup.2 each, independently of one another, denote O, (CO)O or O(CO).

14. The medium according to claim 1, wherein Sp denotes straight-chain alkyl having 1 to 15 C atoms where one or more CH.sub.2 groups may each be replaced by O in such a way that no two 0 atoms in the molecule are connected directly to one another.

15. The medium according to claim 1, wherein Sp denotes straight-chain alkyl having 1 to 10 C atoms where one or more CH.sub.2 groups may each be replaced by O in such a way that no two O atoms in the molecule are connected directly to one another.

16. The medium according to claim 1, wherein R denotes straight-chain or branched alkyl having 1 to 7 C atoms.

17. The medium according to claim 1, wherein X.sup.1 and X.sup.2 each, independently of one another, denote O, (CO)O or O(CO), Sp denotes straight-chain alkyl having 1 to 15 C atoms where one or more CH.sub.2 groups may each be replaced by O in such a way that no two O atoms in the molecule are connected directly to one another, and R denotes straight-chain or branched alkyl having 1 to 7 C atoms and.

18. The medium according to claim 1, wherein said one or more compounds of formula I are selected from the following compounds: ##STR00346##

19. The medium according to claim 4, wherein one or more compounds of formula I are of formula I is selected from the following compounds: ##STR00347##

20. The medium according to claim 1, wherein X.sup.1 and X.sup.2 are each, independently of one another, (CO)O or O(CO).

21. The medium according to claim 1, wherein X.sup.1 and X.sup.2 are identical.

22. The medium according to claim 1, wherein Sp denotes straight-chain alkyl having 1 to 20 C atoms.

23. The medium according to claim 1, wherein Sp denotes straight-chain alkyl having 1 to 15 C atoms.

24. The medium according to claim 1, wherein Sp denotes straight-chain alkyl having 1 to 10 C atoms.

25. The medium according to claim 1, wherein R denotes straight-chain or branched alkyl having 1 to 7 C atoms.

26. The medium according to claim 1, wherein R denotes straight-chain or branched alkyl having 1 to 4 C atoms.

27. The medium according to claim 1, wherein said medium is a liquid-crystalline medium having a nematic phase and said one or more compounds of formula I are present in said medium in a concentration in the range from 1 ppm to 2,000 ppm.

28. The medium according to claim 1, wherein said medium is a liquid-crystalline medium having a nematic phase and said one or more compounds of formula I are present in said medium in a concentration in the range from 1 ppm to 1,000 ppm.

29. The medium according to claim 1, wherein said medium is a liquid-crystalline medium having a nematic phase and said one or more compounds of formula I are present in said medium in a concentration in the range from 1 ppm to 500 ppm.

30. The medium according to claim 1, wherein R is ethyl, propyl, butyl, pentyl, hexyl or heptyl.

31. A method of generating an electro-optical effect comprising applying a voltage across a medium comprising one or more compounds of formula I in a concentration in the range from 1 ppm to 5,000 ppm, ##STR00348## in which X.sup.1 and X.sup.2 each, independently of one another, denote O, (CO)O, O(CO), O(CO)O, NH, NY.sup.01 or NH(CO), Y.sup.01 denotes alkyl having 1 to 12 C atoms, Sp denotes straight-chain alkyl having 1 to 20 C atoms, also cycloalkyl, cycloalkylalkyl or alkylcycloalkyl, where one or more CH.sub.2 groups in all these groups may each be replaced by O in such a way that no two O atoms in the molecule are connected directly to one another, and R denotes straight-chain or branched alkyl having 1 to 10 C atoms, also cycloalkyl, cycloalkylalkyl or alkylcycloalkyl, where one or more CH.sub.2 groups in all these groups may each be replaced by O in such a way that no two O atoms in the molecule are connected directly to one another.

32. An electro-optical liquid-crystal display containing a medium comprising one or more compounds of formula I in a concentration in the range from 1 ppm to 5,000 ppm, ##STR00349## in which X.sup.1 and X.sup.2 each, independently of one another, denote O, (CO)O, O(CO), O(CO)O, NH, NY.sup.01 or NH(CO), Y.sup.01 denotes alkyl having 1 to 12 C atoms, Sp denotes straight-chain alkyl having 1 to 20 C atoms, also cycloalkyl, cycloalkylalkyl or alkylcycloalkyl, where one or more CH.sub.2 groups in all these groups may each be replaced by O in such a way that no two O atoms in the molecule are connected directly to one another, and R denotes straight-chain or branched alkyl having 1 to 10 C atoms, also cycloalkyl, cycloalkylalkyl or alkylcycloalkyl, where one or more CH.sub.2 groups in all these groups may each be replaced by O in such a way that no two O atoms in the molecule are connected directly to one another.

33. A medium comprising one or more compounds of formulae IA-1 to IE-1 and IA-2 to IE- in a concentration in the range from 1 ppm to 5,000 ppm, ##STR00350## ##STR00351## wherein Sp denotes straight-chain alkyl having 1 to 20 C atoms, also cycloalkyl, cycloalkylalkyl or alkylcycloalkyl, where one or more CH.sub.2 groups in all these groups may each be replaced by O in such a way that no two O atoms in the molecule are connected directly to one another.

Description

EXAMPLES

(1) The following working examples are intended to explain the invention without restricting it.

Synthesis Examples

(2) Conventional work-up means: water is added if necessary, the mixture is extracted with methylene chloride, diethyl ether, methyl tert-butyl ether (MTBE) or toluene, the phases are separated, the organic phase is dried and evaporated, and the product is purified by distillation under reduced pressure or crystallization and/or chromatography.

Synthesis of 2-ethyldecanedioic acid bis(2,2,6,6-tetramethylpiperidin-4-yl) ester (1)

(3) ##STR00328##

1) Synthesis of 2-ethoxycarbonyl-2-ethyldecanedioic acid diethyl ester A

(4) ##STR00329##

(5) 194.0 ml (1.035 mol) of diethyl malonate are initially introduced in 775.0 ml of tetrahydrofuran (THF), and 497.7 ml (0.995 mol) of lithium diisopropylamide are added dropwise at room temperature (RT). During this addition, the reaction solution warms to 45 C. It is allowed to cool to 30 C., and 200.0 g (796.3 mmol) of 8-bromooctanoic acid ethyl ester, dissolved in 515.0 ml of THF, are added dropwise. The reaction mixture is then warmed to 60 C. and stirred for 56 h. It is allowed to cool to RT, water is carefully added, and the mixture is subsequently carefully neutralized using dilute hydrochloric acid. The reaction product is extracted with methyl tert-butyl ether (MTB ether), dried over sodium sulfate, filtered and evaporated. The crude product formed is reacted further directly without further purification.

2) Synthesis of 2-carboxy-2-ethyldecanedioic acid B

(6) ##STR00330##

(7) 358.0 g (676.1 mmol, 67%) of the carboxylic acid ester crude product A are dissolved in 2300 ml of ethanol, and 363.0 ml (3.92 mol, 32%) of sodium hydroxide solution are added. The reaction mixture is stirred under reflux for 16 h. When the reaction is complete, the reaction mixture (a precipitate forms) is treated slowly with water (the precipitate dissolves) and carefully acidified to pH=1 using 10% HCl. The reaction product is extracted with MTB ether. The combined organic phases are evaporated, and the water still present is separated off azeotropically with toluene. The crude product formed is employed in the next synthesis step without further purification.

3) Synthesis of 2-ethyldecanedioic acid C

(8) ##STR00331##

(9) 242.0 g (68.3%, 602.5 mmol) of the carboxylic acid B are carefully heated to a bath temperature of 250 C. without solvent in a round-bottomed flask with distillation bridge and receiver under an oil-pump vacuum (12 mbar). From 160 C., the oil-pump vacuum drops to about 70 mbar (elimination of CO.sub.2), and a readily volatile component distils into the receiver. When the evolution of gas is complete, the vacuum reaches 15 mbar again. The crude product formed is subsequently distilled at 0.4-0.5 mbar and a top temperature of 192-198 C. The distillate obtained is then dissolved in 100 ml of ethanol and 100 ml of sodium hydroxide solution (32%) and stirred at 40 C. for 4 h (residues of monoester are cleaved here). The ethanol is subsequently separated off by means of distillation in vacuo, and the residue is mixed with water and carefully acidified using 400 ml of HCl (10%). The reaction product is extracted with MTB ether, dried over sodium sulfate, filtered and evaporated, giving 105 g of the product in a purity of 97.1%, which is employed in the next synthesis step without further purification.

(10) .sup.1H NMR (500 MHz, CDCl.sub.3)

(11) =0.93 ppm (t, 7.45 Hz, 3H, CH.sub.3), 1.30 (s, 8H, CH.sub.2), 1.72-1.42 (m, 6H, CH.sub.2), 2.28 (m.sub.c, 1 H, CH.sub.tert(O)OH), 2.35 (t, 7.4 Hz, 2H, CH.sub.2C(O)OH), 10.73 (S.sub.(broad), 2H, C(O)OH).

4) Synthesis of bis(2,2,6,6-tetramethyl-4-piperidinyl-1-oxyl)-2-ethyldecanedioic acid E

(12) ##STR00332##

(13) 108.9 g (457.8 mmol) of the carboxylic acid C, 236.5 g (1.373 mol) of 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl (free radical) and 5.59 g of 4-(dimethylamino)pyridine are dissolved in 700 ml of dichloromethane and cooled to 2 C.-5 C. A solution of 297.5 g (1.442 mol) of N,N-dicyclohexylcarbodiimide in 300 ml of dichloromethane is then added dropwise. The cooling bath is subsequently removed, and the reaction mixture is stirred at room temperature (RT) for 16 h. When the reaction is complete, 86.6 g (686.8 mmol) of oxalic acid dihydrate are carefully added, and the mixture is stirred at RT for one hour. The reaction mixture is filtered through a frit with suction and filtered directly through 4 l of silica gel with dichloromethane (DCM)/MTB ether (9:1). The reaction product obtained is recrystallized twice from well degassed acetonitrile/water (4:1) at +3 C. with stirring, giving 133 g of the product in a purity of 99.8% (HPLC).

(14) MS (EI) 539.5 [M+H.sup.+]

5) Synthesis of 2-ethyldecanedioic acid bis(2,2,6,6-tetramethylpiperidin-4-yl) ester 1

(15) ##STR00333##

(16) 133.0 g (246.4 mmol) of the free radical E are dissolved in 1.33 l of tetrahydrofuran and reduced to the amine using 33.0 g of sponge nickel catalyst (watery, Johnson-Matthey) under a hydrogen pressure of 5 bar at 50 C. for 83.8 h. The crude product obtained is recrystallized from degassed heptane (1:10) at 10 C. The product obtained is subsequently filtered through 1 l of silica gel with MTB ether (removal of residual free radical) and MTB ether/ethanol (1:1). The product obtained is recrystallized from heptane (1:10) at 10 C. and filtered off with suction, giving 83.2 g of the desired product as a white solid in a purity >99.5% (HPLC and GC).

(17) .sup.1H NMR (500 MHz, CDCl.sub.3)

(18) =0.89 ppm (t (superimposed), 7.46 Hz, 5H, CH.sub.3, 2NH), 1.20-1.07 (2s (superimposed), 16H, CH.sub.3, CH.sub.2), 1.36-1.2 (2s (superimposed), 20H, CH.sub.3, CH.sub.2), 1.54-1.38 (m, 2H), 1.65-1.54 (m.sub.c, 4 H), 1.91 (dd, 12.8, 4.08 Hz, 4H), 2.21 (m.sub.c, 1 H, CHC(O)O), 2.27 (t, 7.46 Hz, 2H, CH.sub.2C(O)O), 5.21 (m.sub.c, 2 H, CHOC(O)).

(19) The following compounds can be prepared analogously:

(20) ##STR00334##

Mixture Examples

(21) The following mixtures M1 to M3 are prepared.

Example M1

(22) TABLE-US-00009 CC-3-V 32.00% Clearing point [ C.]: 85.0 CC-3-V1 11.00% n [589 nm, 20 C.]: 0.1089 CC-3-2V1 4.50% [kHz, 20 C.]: +15.3 PP-1-2V1 2.00% .sub.1 [mPa .Math. s, 20 C.]: 89 CCP-3OCF3 7.50% K.sub.1 [20 C.]: 14.4 CCP-5OCF3 1.50% K.sub.3 [20 C.]: 15.1 PUQU-3-F 1.50% V.sub.0 [V]: 1.01 APUQU-2-F 7.00% APUQU-3-F 7.00% PGUQU-3-F 3.00% PGUQU-4-F 8.00% PGUQU-5-F 2.00% DPGU-4-F 5.00% DGUQU-4-F 8.00%

Example M2

(23) TABLE-US-00010 CC-3-V 26.50% Clearing point [ C.]: 94.5 CC-3-V1 10.00% n [589 nm, 20 C.]: 0.1035 CC-3-2V1 6.50% [kHz, 20 C.]: +17.2 CCP-V2-1 10.00% 1 [mPa .Math. s, 20 C.]: 109 APUQU-2-F 8.00% K.sub.1 [20 C.]: 15.8 APUQU-3-F 9.00% K.sub.3 [20 C.]: 16.6 PGUQU-3-F 3.00% V.sub.0 [V]: 1.00 CDUQU-3-F 8.00% DPGU-4-F 4.00% DGUQU-4-F 8.00% DGUQU-2-F 3.00% PGU-4-T 2.00%

Example M3

(24) TABLE-US-00011 CY-3-O2 12.00% Clearing point [ C.]: 86.5 CY-3-O4 2.00% n [589 nm, 20 C.]: 0.1092 CY-5-O2 12.00% [kHz, 20 C.]: 4.2 CCY-3-O1 6.00% .sub.1 [mPa .Math. s, 20 C.]: 155 CCY-3-O2 8.00% K.sub.1 [20 C.]: 14.6 CCY-4-O2 8.00% K.sub.3 [20 C.]: 16.6 CPY-2-O2 9.00% V.sub.0 [V]: 2.08 CPY-3-O2 9.00% PYP-2-3 5.00% CC-3-V1 5.00% CC-3-V 19.00% BCH-32 5.00%
Voltage Holding RatioLight Stability (Sun)

(25) Firstly, the stability of the voltage holding ratio of the respective test mixture itself, of a further sample of this mixture to which the indicated amounts of the compound TINUVIN770 have been added, and of a further sample of this mixture to which the indicated amounts of compound 1 from Example 1 have been added is determined after 5 min at 100 C., at 1 V and 60 Hz (VHR (initial)). The resultant mixtures are investigated for their light stability (sun) in a test cell having an alignment material for planar alignment and flat ITO electrodes. In order to determine the VHR as a function of the sunlight stability, a lamp which emits the wavelength spectrum of sunlight is used. The test is carried out at 20 C., and the irradiation duration corresponds to 30 min. The voltage holding ratio is determined after 5 minutes at a temperature of 100 C., 1 V and 60 Hz (VHR (sun)). The results are summarized in the following tables. For other measurement conditions, see table.

(26) Mixture M1

(27) TABLE-US-00012 Stabilizer Conc. (ppm) VHR (initial) VHR (sun) 96.4 72.4 TINUVIN770 100 98.0 89.3 TINUVIN770 500 98.0 85.7 TINUVIN770 1000 97.8 85.9 COMPOUND (1) 100 97.6 88.7 COMPOUND (1) 500 97.6 82.9 COMPOUND (1) 1000 97.6 78.4
Mixture M2

(28) TABLE-US-00013 Compound Conc. (ppm) VHR (initial) VHR (sun) 95.9 72.2 TINUVIN770 100 97.2 82.9 TINUVIN770 500 96.8 76.4 TINUVIN770 1000 96.9 74.7 COMPOUND (1) 100 96.5 81.5 COMPOUND (1) 500 96.1 75.5 COMPOUND (1) 1000 96.4 71.3
Mixture M3 (Room Temperature, 10 Hz)

(29) TABLE-US-00014 Stabilizer Conc. (ppm) VHR (initial) VHR (sun) 97.1 90.2 TINUVIN770 100 99.1 96.7 TINUVIN770 500 99.0 98.8 TINUVIN770 1000 98.8 97.2 COMPOUND (1) 100 98.9 96.8 COMPOUND (1) 500 98.7 96.9 COMPOUND (1) 1000 98.4 96.3
Mixture M3

(30) TABLE-US-00015 Stabilizer Conc. (ppm) VHR (initial) VHR (sun) 65.8 54.5 TINUVIN770 100 70.0 69.3 TINUVIN770 500 69.5 70.7 TINUVIN770 1000 72.2 70.7 COMPOUND (1) 100 69.4 70.2 COMPOUND (1) 500 69.5 70.2 COMPOUND (1) 1000 69.8 67.8
VHRLight Stability (Backlighting)

(31) Firstly, the stability of the voltage holding ratio of the respective test mixture itself, of a further sample of this mixture to which the indicated amounts of the compound TINUVIN770 have been added, and of a further sample of this mixture to which the indicated amounts of compound 1 from Example 1 have been added is determined after 5 min at 100 C., at 1 V and 60 Hz (0 h). The resultant mixtures are investigated for their light stability (backlighting) in a test cell having an alignment material for planar alignment and flat ITO electrodes. In order to determine the VHR as a function of the light stability in connection with backlighting, sealed test cells having a commercially available backlighting unit are tested. The irradiation duration corresponds to max. 1000 h. After the time intervals indicated, the voltage holding ratio is in each case determined after 5 minutes at a temperature of 100 C., 1 V and 60 Hz. The results are summarized below in the following tables:

(32) TABLE-US-00016 Stabilizer Conc. (ppm) 0 h 48 h 168 h 336 h 504 h 744 h 1000 h Mixture M1 95.4 81.5 69.0 65.1 62.7 61.4 59.7 TINUVIN770 100 97.8 95.9 90.8 86.5 82.9 79.3 76.8 TINUVIN770 500 97.5 95.7 92.6 89.9 87.4 85.0 82.5 TINUVIN770 1000 97.3 96.0 93.9 90.9 88.5 86.5 84.8 COMPOUND (1) 100 97.9 95.8 91.3 87.7 85.4 82.7 79.3 COMPOUND (1) 500 97.5 96.0 93.4 91.0 88.6 84.6 82.0 COMPOUND (1) 1000 97.4 96.5 93.7 90.6 88.0 85.4 82.4 Mixture M2 94.9 84.3 74.2 68.9 66.4 64.4 62.8 TINUVIN770 100 96.7 95.6 92.1 89.7 88.0 83.9 81.7 TINUVIN770 500 96.7 95.8 93.1 90.7 89.1 87.4 85.5 TINUVIN770 1000 96.6 96.3 94.7 92.5 91.0 89.4 87.8 COMPOUND (1) 100 96.1 94.6 90.7 87.4 85.1 83.5 81.6 COMPOUND (1) 500 96.0 94.7 91.9 89.4 87.7 86.4 84.8 COMPOUND (1) 1000 95.5 94.7 91.6 88.9 87.1 85.5 84.2
VHRHeat Stability

(33) Firstly, the stability of the voltage holding ratio of the respective test mixture M1 itself, of a further sample of this mixture to which the indicated amounts of the compound TINUVIN770 have been added, and of a further sample of this mixture to which the indicated amounts of compound 1 from Example 1 have been added is determined after 5 min at 100 C., at 1 V and 60 Hz (initial). The resultant mixtures are investigated for their heat stability in a test cell having an alignment material for planar alignment and flat ITO electrodes. In order to determine the VHR as a function of the heat stability, sealed test cells are stored in a conventional laboratory heating cabinet at 100 C. for 120 h, and the voltage holding ratio is in each case determined after 5 minutes at a temperature of 100 C., 1 V and 60 Hz (VHR (heat, 120 h)). The results are summarized below in the following table:

(34) Mixture M1

(35) TABLE-US-00017 Stabilizer Conc. (ppm) VHR (initial) VHR (heat, 120 h) 96.2 92.5 TINUVIN770 100 97.7 97.5 TINUVIN770 500 97.9 96.0 TINUVIN770 1000 97.6 95.0 COMPOUND (1) 100 97.4 95.8 COMPOUND (1) 500 97.5 95.5 COMPOUND (1) 1000 97.4 94.1
Low-Temperature Stability

(36) 5 ml glass vials are filled with 1 g of the respective test mixture M1 to M3 and stored in a temperature chamber at various temperatures. The samples are investigated daily for the phase stability.

(37) The results are summarized below in the following table:

(38) TABLE-US-00018 Without 1000 ppm of 1000 ppm of Mixture Temp. Stabilizer Tinuvin 770 compound (1) M1 20 C. 792 h 168 h 528 h M2 20 C. 96 h 240 M3 20 C. 192 h 1000 h

(39) The preceding examples can be repeated with similar success by substituting the generically or specifically described reactants and/or operating conditions of this invention for those used in the preceding examples.

(40) From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.