USE OF EUGENOL DERIVATIVES AS STABILIZERS, ORGANIC MATERIAL AND EUGENOL DERIVATIVES

Abstract

The present invention relates to the use of specific eugenol derivatives as stabilizers of organic materials against oxidative, thermal and/or actinic degradation. The present invention also relates to stabilized organic material and to specific eugenol derivatives which are suitable as stabilizers.

Claims

1-15. (canceled)

16. A method of stabilizing an organic material against oxidative, thermal and/or actinic degradation comprising combining the organic material with: a compound according to general Formula I ##STR00052## wherein, respectively independent of one another, X.sup.1 is a linear or branched alkylene radical having 2 to 18 carbon atoms, X.sup.2 is a linear or branched alkylene radical having 1 to 18 carbon atoms, X.sup.3 is a linear or branched alkyl radical having 1 to 18 carbon atoms, A is a d-valent saturated or unsaturated group, a is 2 to 5-b, b is 0 to 3, c is 0 or 1, and d is 1 to 8, or a polymeric compound containing a repeating unit according to general Formula II ##STR00053## wherein X.sup.1, X.sup.2, X.sup.3, a, b and c are defined as previously, and X.sup.4 is hydrogen or a linear or branched alkyl radical having 1 to 18 carbon atoms, and * is an attachment site of the repeating unit according to general Formula II, or a mixture of a plurality of the compounds according to general Formula I and/or polymeric compounds containing a repeating unit according to general Formula II.

17. The method of claim 16, wherein X.sup.1 is a linear alkylene radical having 2 to 6, X.sup.2 is a linear alkylene radical having 1 to 6, X.sup.3 is a linear or branched alkyl radical having 1 to 4 carbon atoms, X.sup.4 is hydrogen or a linear or branched alkyl radical having 1 to 4 carbon atoms, A is a d-valent, aliphatic or aromatic group, a is 2, and b is 0.

18. The method of claim 16, wherein the compound of general Formula I is one of the following compounds: ##STR00054##

19. The method of claim 16, wherein the polymeric compound containing the repeating unit according to general Formula II is selected from the group consisting of homopolymers formed from repeating units according to general Formula II, or copolymers containing the repeating unit according to general Formula II and at least one further repeating unit derived from a radical polymerizable compound.

20. The method of claim 16, wherein the repeating unit according to general Formula II has the following structure ##STR00055##

21. The method of claim 16, wherein the organic material is one or more of plastics, coatings, lubricants, hydraulic oils, engine oils, turbine oils, transmission oils, metal machining fluids, chemicals, and monomers.

22. The method of claim 16, wherein all of the compounds according to general Formula I, the polymeric compound containing a repeating unit according to general Formula II or the mixture of a plurality of the compounds according to general Formula I, and/or the polymeric compounds containing a repeating unit according to general Formula II are contained in the organic material at a proportion by weight of 0.01 to 10.00 by weight.

23. The method of claim 16, wherein the plastic is selected from the group consisting of a) polymers made from olefins or diolefins, polyalkylene-carbon monoxide copolymers, and copolymers in the form of random or block structures, b) polystyrene, polymethylstyrene, poly-alpha-methylstyrene, polyvinylnaphthalene, polyvinylbiphenyl, polyvinyltoluene, styrene-butadiene (SB), styrene-butadiene-styrene (SBS), styrene-ethylene-butylene-styrene (SEBS), styrene-ethylene-propylene-styrene, styrene-isoprene, styrene-isoprene-styrene (SIS), styrene-butadiene-acrylonitrile (ABS), styrene-acrylonitrile (SAN), styrene-acrylonitrile-acrylate (ASA), styrene-ethylene, styrene-maleic anhydride polymers including corresponding graft copolymers, graft copolymers made of methyl methacrylate, styrene-butadiene and ABS (MABS), and hydrogenated polystyrene derivatives, c) halogen-comprising polymers, d) polymers of unsaturated esters, e) polymers of unsaturated alcohols and derivatives, f) polyacetals, copolymers, and blends thereof g) polymers of cyclic ethers, h) polyphenylene oxides and blends thereof with polystyrene and/or polyamides, polyurethanes and polyureas, j) polyamides and blends of polyamides and polyolefins, k) polyimides, polyamide-imides, polyetherimides, polyesterimides, poly(ether)ketones, polysulfones, polyethersulfones, polyarylsulfones, polyphenylene sulfides, polybenzimidazoles, and polyhydantoins, l) polyesters made from aliphatic or aromatic dicarboxylic acids and diols or from hydroxycarboxylic acids, m) polycarbonates, polyester carbonates, and blends, n) cellulose derivatives, o) epoxy resins, p) phenol resins, q) unsaturated polyester resins produced from unsaturated dicarboxylic acids and diols with vinyl compounds, and alkyd resins, r) silicones and silicones terminated with vinyl groups, and s) mixtures, combinations, or blends of two or more of the above-named polymers.

24. The method of claim 16, wherein at least one further additive is combined or added, wherein the further additive is selected from the group comprising primary antioxidants, secondary antioxidants, UV absorbers, light stabilizers, metal deactivators, filler deactivators, antiozonants, nucleation agents, anti-nucleation agents, toughening agents, plasticizers, lubricants, rheological modifiers, thixotropic agents, chain extenders, optical brighteners, antimicrobial active agents, antistatic agents, slip agents, anti-blocking agents, coupling agents, crosslinking agents, branching agents, anti-cross-linking agents, hydrophilization agents, hydrophobing agents, bonding agents, dispersing agents, compatibilizers, oxygen scavengers, acid scavengers, expanding agents, degradation additives, defoaming agents, odor scavengers, marking agents, anti-fogging agents, additives to increase the electrical conductivity and/or thermal conductivity, infrared absorbers or infrared reflectors, gloss improvers, matting agents, repellents, fillers, reinforcement materials, and mixtures thereof.

25. The method of claim 16, wherein the at least one additive is combined or added in an amount of 0.01 to 9.99% by weight based on the total of the compound according to general Formula I, the organic material, and the at least one additive.

26. A composition comprising an organic material and at least one compound of general Formula I, at least one polymeric compound containing a repeating unit in accordance with general Formula II, or a mixture of a plurality of compounds in accordance with general Formula I and/or polymeric compounds containing a repeating unit in accordance with general Formula II, wherein the compound according to general Formula I is: ##STR00056## wherein, respectively independent of one another, X.sup.1 is a linear or branched alkylene radical having 2 to 18 carbon atoms, X.sup.2 is a linear or branched alkylene radical having 1 to 18 carbon atoms, X.sup.3 is a linear or branched alkyl radical having 1 to 18 carbon atoms, A is a d-valent saturated or unsaturated group, a is 2 to 5-b, b is 0 to 3, c is 0 or 1, and d is 1 to 8, the polymeric compound containing a repeating unit according to general Formula II is ##STR00057## wherein X.sup.1, X.sup.2, X.sup.3, a, b and c are defined above, X.sup.4 is hydrogen or a linear or branched alkyl radical having 1 to 18 carbon atoms, and * is an attachment site of the repeating unit according to general Formula II, or a mixture of a plurality of the compounds according to general Formula I and/or polymeric compounds containing a repeating unit according to general Formula II.

27. The composition in accordance with claim 26, which has the following composition: 0.01 to 10.00% by weight of at least one compound of general Formula I, at least one polymeric compound containing a repeating unit according to general Formula II, or a mixture of a plurality of the compounds according to general Formula I and/or polymeric compounds containing a repeating unit according to general Formula II, 99.99 to 90.00% by weight of the at least one organic material, and 0 to 9.99% by weight of at least one additive, wherein the components add up to 100% by weight.

28. The composition in accordance with claim 27, which is a plastic composition, and wherein the at least one additive is selected from the group consisting of secondary and/or primary antioxidants, UV absorbers, light stabilizers, hydroxylamine based stabilizers, benzofuranone based stabilizers, nucleating agents, toughness improvers, plasticizers, mold lubricants, rheological modifiers, chain extenders, processing aids, pigments, dyes, optical brighteners, antimicrobial active agents, antistatic agents, slip agents, anti-blocking agents, coupling agents, dispersing agents, compatibilizers, oxygen scavengers, acid scavengers, costabilizers, marking agents, and anti-fogging agents.

29. A compound of one of the following formulas: ##STR00058## or a polymeric compound containing a repeating unit according to general Formula II ##STR00059## wherein, respectively independent of one another, X.sup.1 is a linear or branched alkylene radical having 2 to 18 carbon atoms, X.sup.2 is a linear or branched alkylene radical having 1 to 18 carbon atoms, X.sup.3 is a linear or branched alkyl radical having 1 to 18 carbon atoms, X.sup.4 is hydrogen or a linear or branched alkyl radical having 1 to 18 carbon atoms, * is an attachment site of the repeating unit according to general Formula II, A is a d-valent saturated or unsaturated group, a is 2 to 5-b, b is 0 to 3, c is 0 or 1, and d is 1 to 8.

Description

EMBODIMENTS

A) Production of Stabilizers in Accordance with the Invention

a. Synthesis of the Triethylsilyl-Protected Eugenol

[0199] ##STR00039##

[0200] In a heated 250 ml three-necked flask with a septum, reflux condenser and a nitrogen inlet, 125 mg (1.00 eq., 0.24 mmol) of tris(pentafluorophenyl)borane are first placed in a nitrogen countercurrent. In a separate 100 mL Schlenk flask, 42.00 mL (2.02 eq, 30.66 g, 263.67 mmol) triethylsilane and 20 mL (1.00 eq, 21.40 g, 130.33 mmol) eugenol are stirred together for 10 min. The triethylsilane-eugenol mixture is then slowly added to the three-necked flask via a septum using a nitrogen-purged syringe, wherein a strong formation of gas and generation of heat occurs. The reaction mixture subsequently turns a yellow color which, however, disappears again during the course of stirring at room temperature for 4 hours. After the reaction time has elapsed, the reaction mixture is taken up in 100 mL dichloromethane and passed through a neutral aluminum oxide column. The reaction mixture is concentrated by rotary evaporation and residues of triethylsilane still present are distilled off under vacuum. 46.93 g of a light yellow liquid are obtained. The yield amounts to 95.20%.

b. Synthesis of the Triethylsilyl-Protected 1,4-Butanediol Bis(Thioglycolate) Urushiol Thioether

[0201] ##STR00040##

[0202] In a 100 mL Schlenk flask, 2.20 g (1.00 eq., 9.23 mmol) 1,4-butanediol bis(thioglycolate) are mixed with 7.00 g (2.00 eq., 18.51 mmol) of the triethyl-protected eugenol. The reaction mixture is degassed once using the freeze-pump-thaw method and then a small amount of Irgacure 819 is added in a nitrogen countercurrent. Afterwards, the reaction mixture is irradiated with stirring at a wavelength of 366 nm under a nitrogen atmosphere. The progress of the reaction is followed by means of .sup.1H-NMR spectroscopy by taking regular samples. A significant increase in viscosity can already be seen after 30 min and the reaction is complete. after 20 h. The yield amounts to 99.50%.

c. Deprotection of the Triethylsilyl-Protected 1,4-Butanediol Bis(Thioglycolate) Urushiol Thioether

[0203] ##STR00041##

[0204] In a 100 mL round bottom flask, 3.00 g (3.02 mmol) of the triethylsilane-protected 1,4-butanediol bis(thioglycolate) urushiol thioether are dissolved in 30 mL of ethanol. 1.20 mL of 1 M hydrochloric acid are then added, wherein a white turbidity occurs, which subsequently disappears again. The reaction mixture is stirred overnight and 15 mL of a saturated sodium bicarbonate solution and 40 mL of distilled water are added the following day. The reaction mixture is extracted three times with 30 mL ethyl acetate each time. The combined organic extracts are washed again with 40 mL of a saturated sodium chloride solution and finally evaporated. The residue is taken up in 60 mL tetrahydrofuran and passed through a frit with a thin layer of silica gel. The filtrate is concentrated by rotary evaporation and finally distilled again under vacuum. After cooling, 1.31 g (2.43 mmol) of a white, waxy solid are obtained. The yield amounts to 80.46%.

TABLE-US-00001 TABLE 1 Overview of the thermogravimetric analyses of the synthesized 1,4-butanediol bis(thioglycolate) urushiol thioether. Loss of mass [%] Temperature [ C.] 5.0 289.81 10.0 311.44 50.0 367.33

d. Synthesis of the Triethylsilyl-Protected Pentaerythritol Tetrakis(3-Mercaptopropionate) Urushiol Thioether

[0205] ##STR00042##

[0206] In a 100 mL Schlenk flask, 6.40 g (1.00 eq., 13.10 mmol) pentaerythritol tetrakis(3-mercaptopropionate) are mixed with 19.82 g (4.00 eq., 52.40 mmol) of the triethyl-protected eugenol. The reaction mixture is degassed once using the freeze-pump-thaw method and then a small amount of IRGACURE 819 is added in a nitrogen countercurrent. Afterwards, the reaction mixture is irradiated with stirring at a wavelength of 366 nm under a nitrogen atmosphere. The progress of the reaction is followed by means of .sup.1H-NMR spectroscopy by taking regular samples. A significant increase in viscosity can already be seen after 30 min and the reaction is complete. after 48 h. The yield amounts to 99.87%.

e. Deprotection of the Triethylsilyl-Protected Pentaerythritol Tetrakis(3-Mercaptopropionate) Urushiol Thioether

[0207] ##STR00043##

[0208] In a 100 mL round bottom flask, 3.02 g (1.51 mmol) of the triethylsilane-protected pentaerythritol tetrakis(3-mercaptopropionate) urushiol thioether are placed in 30 mL ethanol. 1.50 mL of 1 M hydrochloric acid are then added, wherein a white turbidity occurs, which subsequently disappears again. The reaction mixture is stirred overnight and 15 mL of a saturated sodium bicarbonate solution and 40 mL of distilled water are added the following day. The reaction mixture is extracted three times with 30 mL ethyl acetate each time. The combined organic extracts are washed again with 40 mL of a saturated sodium chloride solution and finally evaporated. The residue is taken up in 60 mL tetrahydrofuran and passed through a frit with a thin layer of silica gel. The filtrate is concentrated by rotary evaporation and finally distilled again under vacuum. After cooling, 1.09 g (1.00 mmol) of a light yellow, viscous liquid are obtained. The yield amounts to 66.23%.

TABLE-US-00002 TABLE 2 Overview of the thermogravimetric analyses of the synthesized pentaerythritol tetrakis(3- mercaptopropionate) urushiol thioether. Loss of mass [%] Temperature [ C.] 5.0 282.30 10.0 319.71 50.0 379.18

f. Synthesis of the Triethylsilyl Octadecanethiol Urushiol Thioether

[0209] ##STR00044##

[0210] In a 100 mL Schlenk flask, 5.48 g (1.00 eq., 19.12 mmol) octadecanethiol are mixed with 7.00 g (0.97 eq., 18.51 mmol) of the triethyl-protected eugenol. The reaction mixture is degassed once using the freeze-pump-thaw method and then a small amount of IRGACURE 819 is added in a nitrogen countercurrent. Afterwards, the reaction mixture is irradiated with stirring at a wavelength of 366 nm under a nitrogen atmosphere. The progress of the reaction is followed by means of .sup.1H-NMR spectroscopy by taking regular samples. A significant increase in viscosity can already be seen after 30 min and the reaction is complete. after 24 h. The yield amounts to 99.27%.

g. Deprotection of the Triethylsilyl Octadecanethiol Urushiol Thioether

[0211] ##STR00045##

[0212] In a 100 mL round bottom flask, 5.40 g (8.13 mmol) of the triethylsilane-protected octadecanethiol urushiol thioether are dissolved in 30 mL of ethanol. 0.8 mL of concentrated hydrochloric acid are then added, wherein a white turbidity occurs, which subsequently disappears again After 3 h, 10 mL of distilled water are added dropwise to the solution, wherein a white precipitate separates out. This is filtered off and finally recrystallized from methanol. 3.36 g (7.70 mmol) of a white solid are obtained. The yield amounts to 94.72%.

TABLE-US-00003 TABLE 3 Overview of the thermogravimetric analyses of the synthesized octadecanethiol urushiol thioether. Loss of mass [%] Temperature [ C.] 5.0 295.80 10.0 318.62 50.0 373.76

h. Synthesis of (3R,6S)-hexahydrofuro[3,2-b]furan-3,6-diyl bis(3-((3-(3,4-bis((triethylsilyl)oxy)phenyl)propyl)thio)propanoate)

[0213] ##STR00046##

[0214] In a 100 mL Schlenk flask, 7.00 g (1.00 eq., 21.74 mmol) isosorbide bis-(3-mercapto)propionate are placed in 16.44 g (2.00 eq., 43.47 mmol) of the triethyl-protected eugenol. The reaction mixture is degassed once using the freeze-pump-thaw method and then a small amount of IRGACURE 819 is added in a nitrogen countercurrent. Afterwards, the reaction mixture is irradiated with stirring at a wavelength of 366 nm under a nitrogen atmosphere, wherein the reaction mixture is gradually homogenized. The progress of the reaction is followed by means of .sup.1H-NMR spectroscopy by taking regular samples. The reaction mixture has homogenized after 24 h and the reaction is complete after 96 h. The yield amounts to 99.26%.

i. Deprotection of (3R,6S)-hexahydrofuro[3,2-b]furan-3,6-diyl bis(3-((3-(3,4-bis((triethylsilyl)oxy)phenyl)propyl)thio)propanoate)

[0215] ##STR00047##

[0216] 7.32 g (1.00 eq., 6.79 mmol) (3R,6S)-hexahydrofuro[3,2-b]furan-3,6-diyl bis(3-((3-(3,4-bis((triethylsilyl)oxy)phenyl)propyl)thio)propanoate) and 35 mL ethanol are placed in a 100 mL round bottom flask. 3.5 mL of 1M hydrochloric acid are added while stirring, wherein in a white, voluminous precipitate results, which redissolves. After 24 h, the reaction mixture is poured into 40 mL saturated sodium bicarbonate and the aqueous solution is extracted three times with 40 mL ethyl acetate each time. The organic phase is dried over sodium sulfate and the solvent is then removed on a rotary evaporator. Finally, the residue is distilled again under high vacuum, wherein 2.73 g (4.38 mmol) of a highly viscous, red-orange gel remains. The yield amounts to 64.51%.

TABLE-US-00004 TABLE 4 Overview of the results of the thermogravimetric analysis of hexahydrofuro[3,2-b]furan-3,6- diyl bis((3-((3-(3,4-dihydroxyphenyl)propyl)thio)propanoate under nitrogen atmosphere. Loss of mass [%] Temperature [ C.] 5.0 278.12 10.0 299.22 50.0 351.33

j. Thiol-ene reaction of mercaptoethanol with the triethylsilyl-protected eugenol

[0217] ##STR00048##

[0218] 3.70 mL (1.00 eq., 53.03 mmol) mercaptoethanol and 20.02 g (1.00 eq., 52.93 mmol) of the triethyl-protected eugenol are placed in a 100 mL Schlenk flask. The reaction mixture is degassed once using the freeze-pump-thaw method and then a small amount of Irgacure 819 is added in a nitrogen countercurrent. Afterwards, the reaction mixture is irradiated with stirring at a wavelength of 366 nm under a nitrogen atmosphere. The progress of the reaction is followed by means of .sup.1H-NMR spectroscopy by taking regular samples. A significant increase in viscosity can already be seen after 15 min and the reaction is complete. after 12 hours. Excess mercaptoethanol is removed by vacuum distillation. The yield amounts to 99.87%.

k. Methacrylate of Hydroxy-End-Functionalized Triethylsilyl-Protected Eugenol

[0219] ##STR00049##

[0220] In a heated 500 mL three-necked flask with dropping funnel and septum, 22.03 g (1.00 eq., 48.28 mmol) of the hydroxy-end-functionalized triethylsilyl-protected eugenol are dissolved via the thiol-ene reaction with mercaptoethanol in 100 mL dried chloroform in a nitrogen atmosphere. 10.10 mL (1.51 eq., 72.86 mmol) triethylamine are then added in a nitrogen countercurrent. The reaction mixture is cooled for 30 min in an ice bath. Afterwards, a solution of 5.10 mL (1.1 eq., 53.03 mmol) methacryloyl chloride and 60 mL dry chloroform is slowly added dropwise. After the addition is complete, the reaction mixture is stirred at room temperature overnight and washed 3 times with distilled water the following day. The reaction mixture is then passed through a neutral aluminum oxide column and the solvent is evaporated by rotary evaporation. After cooling, 13.54 g (25.79 mmol) of a yellow, viscous liquid are obtained. The yield amounts to 53.43%.

l. Synthesis of poly(2-((3-(3,4-dihydroxyphenyl)propyl)thio)ethyl methacrylate)

[0221] ##STR00050##

[0222] In a 100 mL Schlenk flask, 10.00 g (1.00 eq., 19.07 mmol) of 2-((3-(3,4-dihydroxyphenyl)propyl)thio)ethyl methacrylate and 90 mg (0.03 eq., 0.55 mmol) azobis(isobutyronitrile) recrystallized from methanol are dissolved in 40 mL toluene. The solution is degassed three times using the freeze-pump-thaw method and the reaction solution is then heated to 73 C. overnight under a nitrogen atmosphere. A significant increase in viscosity can be seen after 30 min. The flask is immediately transferred to an ice bath the following day and the polymer is then precipitated in 300 mL of methanol. After drying, the transparent gel is taken up in 100 mL tetrahydrofuran and mixed with 3.00 mL 1 M hydrochloric acid. After 48 h, the polymer is then precipitated in 400 mL of n-hexane. After drying at 80 C. under high vacuum, 3.57 g of a white-beige solid are obtained.

TABLE-US-00005 TABLE 5 Overview of the results of the thermogravimetric analysis of the poly(2-((3-(3,4-dihydroxyphenyl)propyl)thio)ethyl methacrylate) under nitrogen atmosphere. Loss of mass [%] Temperature [ C.] 5.0 283.69 10.0 305.23 50.0 358.09

TABLE-US-00006 TABLE 6 Overview of the average molecular weight and the dispersity of the synthesized poly(2-((3-(3,4-dihydroxyphenyl)propyl)thio)ethyl methacrylate) determined by means of gel permeation chromatography. Mn [g/mol] 11100 2.54

m. Synthesis of Polystearyl methacrylate-co-poly(2-((3-(3,4-dihydroxyphenyl)propyl)thio)ethyl methacrylate) Copolymer

[0223] ##STR00051##

[0224] In a 100 mL Schlenk flask, 11.00 g (1.00 eq., 20.96 mmol) of 2-((3-(3,4-dihydroxyphenyl)propyl)thio)ethyl methacrylate, 3.05 g (0.43 eq., 9.01 mmol) of destabilized stearyl methacrylate and 72 mg (0.02 eq., 0.44 mmol) azobis(isobutyronitrile) recrystallized from methanol are dissolved in 32 mL toluene. The solution is degassed three times using the freeze-pump-thaw method and the reaction solution is then heated to 73 C. overnight under a nitrogen atmosphere. A significant increase in viscosity can be seen after 30 min. The flask is immediately transferred to an ice bath the following day and the polymer is then precipitated in 350 mL of methanol. After drying, the transparent gel is taken up in 100 mL tetrahydrofuran and mixed with 3.00 mL 1 M hydrochloric acid and a few drops of ethanol. The progress of the desilylation is checked by taking precipitation samples in n-hexane with subsequent .sup.1H-NMR analysis. After 360 h, the polymer is then precipitated in 500 mL of n-hexane. After drying at 80 C. under high vacuum, 3.08 g of a white-beige, slightly greasy solid are obtained.

TABLE-US-00007 TABLE 7 Overview of the results of the thermogravimetric analysis of the polystearyl methacrylate-co-poly(2- ((3-(3,4-dihydroxyphenyl)propyl)thio)ethyl methacrylate) copolymer under nitrogen atmosphere. Loss of mass [%] Temperature [ C.] 5.0 309.15 10.0 324.29 50.0 376.25

TABLE-US-00008 TABLE 8 Overview of the average molecular weight and the dispersity of the synthesized random copolymer determined by means of gel permeation chromatography. Mn [g/mol] 29400 2.56

B) Application Check

[0225] To examine the effect of the stabilizers according to the invention, a commercial polypropylene (Moplen HP 501N, Lyondell Basell Industries) was homogenized in a powder-powder mixture with the stabilizers stated in Table 9 and was circulated in a twin-screw microextruder (MC 5, manufacturer DSM) for 30 minutes at 200 C. and 200 revolutions per minute and the decrease in the force was recorded. The force is a direct measure for the molecular weight of polypropylene; the smaller the reduction, the higher the stabilization effect.

TABLE-US-00009 TABLE 9 Stabilization of polypropylene with antioxidants according to the invention Residual strength after 10/20/30 minutes [%], respective mean values from 2 tests) Additive (% by weight) 0 min = 100% Comparison example 1 Without additive 51/26/13 Comparison example 2 0.5% pentaerythritol tetrakis(3-(3,5-di- 84/79/75 (commercial stabilizer) tert-butyl-4-hydroxyphenyl)propionate) Comparison example 3 0.5% 5-octadecyl-3-(3,5-di-tert-butyl-4- 82/71/60 (commercial stabilizer) hydroxyphenyl)propionate Example 1 in 0.5% 1,4-butanediol bis(thioglycolate) 97/95/94 accordance with the urushiol thioether invention Example 2 in 0.5% pentaerythritol tetrakis(3- 96/96/95 accordance with the mercaptopropionate) urushiol thioether invention Example 3 in 0.5% octadecanethiol urushiol thioether 96/94/91 accordance with the invention Example 4 in 0.5% hexahydrofuro[3,2-b]furan-3,6-diyl 92/90/89 accordance with the bis((3-((3-(3,4- invention dihydroxyphenyl)propyl)thio)propanoate Example 5 in 0.5% poly(2-((3-(3,4- 86/80/74 accordance with the dihydroxyphenyl)propyl)thio)ethyl invention methacrylate) Example 6 in 0.5% polystearyl methacrylate-co- 90/85/81 accordance with the poly(2-((3-(3,4- invention dihydroxyphenyl)propyl)thio)ethyl methacrylate)

[0226] The additives in accordance with the invention show a very good stabilization effect since a smaller reduction of the polymer takes place over the trial period in comparison to an unstabilized polymer and a polymer stabilized with standard antioxidants.

[0227] In further experiments, stabilizer compositions according to the invention were tested with regard to their effect (Table 10).

TABLE-US-00010 TABLE 10 Stabilization of polypropylene with stabilizer compositions according to the invention Residual strength after 10/20/30 minutes [%], respective mean values from 2 tests) Additive (% by weight) 0 min = 100% Comparison Without additive 51/26/13 example 1 Example 7 in 0.25% 1,4-butanediol bis(thioglycolate) 97/96/96 accordance with urushiol thioether the invention 0.25% tris-(2,4-di-tert- butylphenyl)phosphite Example 8 in 0.25% pentaerythritol tetrakis(3- 97/96/95 accordance with mercaptopropionate) urushiol thioether the invention 0.25% tris-(2,4-di-tert- butylphenyl)phosphite Example 9 0.25% octadecanethiol urushiol thioether 97/95/94 according to the 0.25% tris-(2,4-di-tert- invention butylphenyl)phosphite Example 10 0.25% hexahydrofuro[3,2-b]furan-3,6-diyl 97/96/95 according to the bis((3-((3-(3,4- invention dihydroxyphenyl)propyl)thio)propanoate 0.25% tris-(2,4-di-tert- butylphenyl)phosphite Example 11 0.25% 1,4-butanediol bis(thioglycolate) 96/95/92 according to the urushiol thioether invention 0,25% erythritol Example 12 0.25% poly(2-((3-(3,4- 93/88/81 according to the dihydroxyphenyl)propyl)thio)ethyl invention methacrylate) 0.25% tris-(2,4-di-tert- butylphenyl)phosphite Example 13 0.25% polystearyl methacrylate-co-poly(2- 92/87/83 according to the ((3-(3,4-dihydroxyphenyl)propyl)thio)ethyl invention methacrylate) 0.25% tris-(2,4-di-tert- butylphenyl)phosphite

[0228] The compositions in accordance with the invention display a very good stabilization effect since a smaller reduction of the polymer takes place over the trial period in comparison to the comparison examples.

C) Oxidation Induction Time Analyses

[0229] The determination of the oxidation induction time (OIT) represents a possible method for assessing the efficacy of stabilizers. This analysis method is based on the reaction of the polymer to be examined with atmospheric oxygen. The sample is thereby initially melted and equilibrated under an inert gas atmosphere up to the selected measuring temperature above the melting temperature of the polymer. A switch of the flushing gas from inert gas to air is then carried out, wherein the heat flow is detected over the course of time. During consumption of the added stabilizer, an increase in the heat flow occurs as a result of the exothermic thermo-oxidative damage to the polymer. The OIT value results from the determination of the time until oxidation occurs, that is, the onset. In principle, the higher the OIT value, the longer the sample was stabilized by the antioxidant and the effectiveness is correspondingly greater. Table 11 summarizes the OIT values for compounds in which the stabilizers described in the patent have been incorporated at 0.5% by weight, for various temperatures. Polypropylene (Moplen HP 500N, Lyondell Basell Industries) was used as the polymer.

TABLE-US-00011 TABLE 11 Overview of OIT values at 220 C. for stabilizer compositions according to the invention. OIT value Additive (% by weight) [min] Comparison example 1 Without additive 5 Comparison example 2 0.5% octadecyl-3-(3,5-di-tert-butyl-4- 123 (commercial stabilizer) hydroxyphenyl)propionate (Irganox 1076) Comparison example 3 0.5% 2-methyl-4,6- 108 (commercial stabilizer) bis(octylsulfanylmethyl)phenol (Irganox 1520) Example 1 in 0.5% 1,4-butanediol bis(thioglycolate) 82 accordance with urushiol thioether the invention Example 2 in 0.5% pentaerythritol tetrakis(3- 70 accordance with mercaptopropionate) urushiol thioether the invention Example 3 in 0.5% hexahydrofuro[3,2-b]furan-3,6-diyl 105 accordance with bis((3-((3-(3,4- the invention dihydroxyphenyl)propyl)thio)propanoate Example 4 in 0.5% octadecanethiol urushiol 198 accordance with thioether the invention Example 5 in 0.5% poly(2-((3-(3,4- 97 accordance with dihydroxyphenyl)propyl)thio)ethyl the invention methacrylate) Example 6 in 0.5% polystearyl methacrylate-co-poly(2- 87 accordance with ((3-(3,4- the invention dihydroxyphenyl)propyl)thio)ethyl methacrylate)

[0230] All synthesized and described compounds lead to a substantial increase in the OIT value and thus contribute to a substantial increase in the thermo-oxidative stability of the polymer. The OIT value, in particular for the octadecanethiol urushiol thioether, lies considerably above the values for the compounds with the commercial stabilizers.