USE OF HYDROXYCINNAMIC ACID SALTS FOR STABILIZING ORGANIC MATERIALS, STABILIZED ORGANIC MATERIAL, METHOD FOR STABILIZING ORGANIC MATERIALS, SPECIFIC STABILIZERS AND STABILIZER COMPOSITIONS

Abstract

The invention relates to the use of specific hydroycinnamic acid salts for stabilizing organic materials. The invention also relates to a corresponding organic material stabilized by incorporating a specific hydroxycinnamic acid salt, and to a method for stabilizing organic materials. In addition, a specific aluminum salt of a hydroxycinnamic acid suitable as an organic stabilizer is described. The invention further relates to a stabilizer composition comprising a corresponding hydroxycinnamic acid salt.

Claims

1-17. (canceled)

18. A method for stabilizing an organic material comprising combining the organic material with a compound or a mixture of compounds in accordance with general formula I ##STR00043## wherein R.sup.1, R.sup.2, and R.sup.3 are each selected independently of one another from the group consisting of hydroxy, linear or branched alkoxy group having 1 to 6 carbon atoms, and hydrogen, with the proviso that at least one of the residues R.sup.1, R.sup.2 and R.sup.3 is a hydroxy residue, M is selected from the group consisting of metals, and n is a integer from 1 to 4.

19. The method of claim 18, wherein the compound stabilizes the organic material against oxidative, thermal and/or actinic degradation.

20. The method of claim 18, wherein the organic material is selected from plastics, coatings, lubricants, hydraulic oils, engine oils, turbine oils, transmission oils, metal machining liquids, chemicals, and monomers.

21. The method of claim 18, wherein the residues R.sup.1, R.sup.2, and R.sup.3 each represents a hydroxy residue, two of the residues R.sup.1, R.sup.2, and R.sup.3 represent a hydroxy residue and one of the residues R.sup.1, R.sup.2, and R.sup.3 represents hydrogen or a linear or branched alkoxy group having 1 to 6 carbon atoms, one of the residues R.sup.1, R.sup.2, and R.sup.3 represents a hydroxy residue and two of the residues R.sup.1, R.sup.2, and R.sup.3 represent a linear or branched alkoxy group having 1 to 6 carbon atoms, or one each of the residues R.sup.1, R.sup.2 and R.sup.3 represents a hydroxy residue, a linear or branched alkoxy group having 1 to 6 carbon atoms, and hydrogen.

22. The method of claim 18, wherein the compound in accordance with general formula I is selected from the group consisting of the following compounds: ##STR00044##

23. The method of claim 18, wherein M is selected from the group consisting of alkali metals, alkaline earth metals, aluminum, and zinc.

24. The method of claim 18, wherein the compound in accordance with general formula I or, in the case of a mixture of a plurality of compounds in accordance with general formula I, the totality of all the compounds in accordance with general formula I is included in the organic material at a weight proportion of 0.01 to 10.00 wt. %.

25. The method of claim 18, wherein the plastic is selected from the group consisting of a) polyethylene, metallocene PE (m-PE), polypropylene, polyisobutylene, poly-4-methyl-pentene-1, polybutadiene, polyisoprene, polycyclooctene, polyalkylene carbon monoxide copolymers, polypropylene polyethylene (EP) copolymer, EPM or EPDM copolymer, ethylene vinyl acetate (EVA) copolymer, ethylene acrylic ester copolymer, ethylene acrylic acid copolymer and its salts, ethylene acrylic acid glycidyl(meth)acrylate terpolymer, polypropylene graft maleic acid anhydride, polypropylene graft acrylic acid, polyethylene graft acrylic acid, polyethylene polybutyl acrylate graft maleic acid anhydride, and blends thereof, b) polystyrene, polymethylstyrene, poly-alpha-methylstyrene, polyvinyl naphthalene, polyvinyl biphenyl, polyvinyl toluol, 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 acid anhydride polymers, graft copolymers of styrene on butadiene, graft copolymers of maleic acid anhydride on SBS or SEBS, graft copolymers of methylmethacrylte, styrene butadiene, and ABS (MABS), and hydrated polystyrene derivatives; c) halogen-containing polymers selected from the group consisting of polyvinyl chloride (PVC), polychloroprene, and polyvinylidene chloride (PVDC), copolymers of vinyl chloride and vinylidene chloride or composed of vinyl chloride and vinyl acetate, chlorinated polyethylene, polyvinylidene fluoride, and epichlorohydrin homo and copolymer thereof, d) polymers of unsaturated esters selected from the group consisting of polymethyl methacrylate (PMMA), polybutyl acrylate, polyauryl acrylate, poly stearyl acrylate, and polyglycidyl methacrylate, polyacrylonitrile, polyacrylamides, and polyacrylonitrile-poly alkyl acrylate; e) polymers of unsaturated alcohols and derivatives selected from the group consisting of polyvinyl alcohol, polyvinyl acetate, polyvinyl butyrate, and poly allyl phthalate, and poly allyl melamine; f) polyacetates; g) polyphenylene oxides and blends with polystyrene or polyamides, h) polymers of cyclic ethers; i) polyurethanes of hydroxy terminated polyethers or polyesters and aromatic or aliphatic isocyanates, and polyureas; j) polyamides selected from the group consisting of polyamide-6, 6.6, 6.10, 4.6, 4.10, 6.12, 10.10, 10.12, 12.12, polyamide 11, polyamide 12, partly or fully aromatic polyamides, blends of different polyamides, and blends of polyamides and polyolefins; k) a polymer selected from the group consisting of polyamides, polyamide imides, polyether imides, polyester imides, poly(ether)ketones, polysulfones, polyether sulfones, polyaryl sulfones, polyphenylene sulfides, polybenzimide azoles, and polyhydantoines; l) polyesters of aliphatic or aromatic dicarboxylic acids and diols or of hydroxy carboxylic acids; m) polycarbonates, polyester carbonates, and blends; n) cellulose derivatives, o) epoxy resins, p) phenol resins; q) unsaturated polyester resins of unsaturated dicarboxylic acids and diols with vinyl compounds; r) silicones; and s) mixtures, combinations, or blends of two or more of the above-named polymers.

26. The method of claim 18, wherein the plastic comprises at least one further additive.

27. The method of claim 26, wherein the further additive is selected from the group consisting of primary and/or secondary antioxidants, UV absorbers, light stabilizers, stabilizers on a hydroxyl amine base, stabilizers on a benzofuranone base, 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.

28. The method of claim 27, wherein the at least one additive is added or is included in an amount of 0.01 to 80 wt % with respect to the totality of the at least one compound in accordance with formula I of the organic material and of the at least one additive.

29. The method of claim 18, wherein the compound or mixtures of a plurality of compound in accordance with the general formula I is/are combined along with a costabilizer.

30. The method of claim 29, wherein the costabilizer is selected from the group consisting of polyols, hyper branched polymers/oligomers or dendrimers having alcohol groups, threitol, erythritol, galactitol, mannitol, ribitol, sorbitol, xylitol, arabitol, isomaltol, lactitol, maltitol, altritol, iditol, maltotritol, and hydrated oligo- and polysaccharides having polyol end groups, and mixtures thereof.

31. A composition comprising an organic material in combination with at least one compound in accordance with general formula I or a mixture of a plurality of compounds in accordance with general formula I as a stabilizer ##STR00045## wherein R.sup.1, R.sup.2, and R.sup.3 are each selected independently of one another from the group consisting of hydroxy, linear or branched alkoxy group having 1 to 6 carbon atoms, and hydrogen, with the proviso that at least one of the residues R.sup.1, R.sup.2 and R.sup.3 is a hydroxy residue, M is selected from the group consisting of metals, and n is a integer from 1 to 4.

32. The composition of claim 31, having the following composition 0.01 to 10.00 wt % of a compound in accordance with the general formula I or, in the case of a mixture of a plurality of compounds in accordance with the general formula I, the totality of all of the compounds in accordance with the general formula I, 99.99 to 10.00 wt % of at least one organic material, and 0 to 80.00 wt % of at least one additive, wherein the components add up to 100%.

33. The composition of claim 32, wherein the at least one additive is selected from the group consisting of primary and/or secondary antioxidants, UV absorbers, light stabilizers, stabilizers on a hydroxyl amine base, stabilizers on a benzofuranone base, 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.

34. A compound in accordance with the general formula I ##STR00046## wherein R.sup.1, R.sup.2, and R.sup.3 are each selected independently of one another from the group consisting of hydroxy, linear or branched alkoxy groups having 1 to 6 carbon atoms, and hydrogen, with the proviso that at least one of the residues R.sup.1, R.sup.2, and R.sup.3 is a hydroxy residue, and M is aluminum, and n is 3.

35. A stabilizer composition comprising a) a compound or mixtures of a plurality of compounds in accordance with claim 34; and b) at least one secondary antioxidant selected from the group consisting of phosphites, phosphonites, and thiols, or at least one costabilizer selected from the group consisting of polyols, acid scavengers, sterically hindered amines, and mixtures and combinations thereof (component B).

36. The stabilizer composition of claim 35, wherein component A and component B are present in a weight ratio of 100:1 to 1:100, 10:1 to 1:10, or 4:1 to 1:4.

Description

EMBODIMENTS

[0141] A) Preparation of the Hydroxycinnamic Acid Salts in Accordance with the Invention

A1) Synthesis of the Sodium Ferulate (NaFa)

[0142] ##STR00039##

[0143] 12.00 g (1.00 eq., 61.80 mmol) ferulic acid (1) are first dissolved in 620 mL methanol in a glass beaker. Subsequently, 2.47 g (1.00 eq., 61.80 mmol) sodium hydroxide are dissolved in 60 mL distilled water and the resulting NaOH solution is dripped into the ferulic acid solution via a drip funnel. The slightly yellow solution is added to 1.5 l acetone after the addition has ended. The precipitated yellow precipitation is filtered, is washed 3 times with 200 mL acetone in each case, and is finally dried in the vacuum drying cabinet at 80° for two days. 10.51 g of a yellow fine-powdered precipitate are obtained. The yield amounts to 78.66%.

A2) Synthesis of the Aluminum Ferulate (AlFa)

[0144] ##STR00040##

[0145] 11.18 g (3.07 eq., 57.57 mmol) ferulic acid are first dissolved in 50 mL methanol. 57 mL of a 1 M NaOH solution is added to the yellow solution. After the solution has been stirred for half an hour, a solution of 2.5 g (1.00 eq., 18.75 mmol) aluminum trichloride and 2.8 mL distilled water are dripped in via a drip funnel. A white precipitate is immediately deposited here that is stirred for a further hour and then filtered. After the washing three times with 200 mL distilled water and 200 mL acetone respectively and after the drying in the vacuum drying cabinet at 80° C. overnight, 5.32 g of a white coarse grain solid are obtained.

A3) Synthesis of the Magnesium Ferulate (MgFa)

[0146] ##STR00041##

[0147] 2.5 g (1.00 eq., 42.86 mmol) magnesium hydroxide are first suspended in 600 mL distilled water in a glass beaker. Subsequently, 16.91 g (2.03 eq., 87.08 mmol) ferulic acid is dissolved while heating into 250 mL methanol and the resulting slightly yellow solution is added to the magnesium hydroxide suspension. The suspension is stirred at room temperature overnight, with the magnesium hydroxide entering into solution. The resulting slightly yellow solution is added to 1.5 l acetone. The precipitated yellow precipitation is filtered, is washed 3 times with 200 mL acetone in each case, and is finally dried in the vacuum drying cabinet at 800 for two days. 2.80 g of a yellow fine-powdered precipitate are obtained. The yield amounts to 15.90%.

A4) Synthesis of the Calcium Ferulate (CaFa)

[0148] ##STR00042##

[0149] 2.00 g (1.00 eq., 26.99 mmol) calcium hydroxide are first suspended in 100 mL distilled water in a glass beaker. Subsequently, 10.48 g (2.00 eq., 53.97 mmol) ferulic acid is dissolved while heating into 100 mL methanol and the resulting slightly yellow solution is added to the calcium hydroxide suspension. The suspension is stirred at room temperature overnight, with the calcium hydroxide entering into solution. At the same time, a silvery residue remains that is filtered. The filtrate is added to 1.5 l acetone. The precipitated yellow precipitation is filtered, is washed 3 times with 200 mL acetone in each case, and is finally dried in the vacuum drying cabinet at 80° for two days. 7.42 g of a yellow fine-powdered precipitate is obtained. The yield amounts to 64.47%.

B) Application Check

[0150] A commercial polypropylene (Molen HP 501B, Lyondell Basell Industries) was homogenized in a powder-powder mixture with the stabilizers or stabilizer mixtures specified in the tables and was conducted in a circuit in a twin screw microextruder (MC 5, manufacturer DSM) at 200° C. and at 200 revolutions per minute for 30 minutes and the reduction of the force was recorded to check the effect of the stabilizers in accordance with the invention. The force is a direct measure for the molecular weight of polypropylene; the smaller the reduction, the higher the stabilization effect.

TABLE-US-00001 TABLE 1 Stabilization of polypropylene Residual force after 10/20/30 Additive minutes [%] Comparison example 1 Without additive 63/39/26 Example 1 in accordance 0.5% sodium ferulate 76/59/44 with the invention Example 2 in accordance % aluminum ferulate 75/61/51 with the invention

TABLE-US-00002 TABLE 2 Stabilization of polypropylene Residual force after 10/20/30 Additives minutes [%] Example 3 in accordance 0.25% sodium ferulate 86/81/75 with the invention and 0.25% erythritol Example 4 in accordance 0.25% aluminum ferulate 85/76/67 with the invention and 0.25% erythritol Example 5 in accordance 0.25% calcium ferulate 73/55/40 with the invention and 0.25% erythritol

TABLE-US-00003 TABLE 3 Stabilization of polypropylene Residual force after 10/20/30 Additives minutes [%] Example 6 in accordance 0.25% sodium ferulate 90/81/70 with the invention and 0.25% methionine

TABLE-US-00004 TABLE 3 Stabilization of polypropylene Residual force after 10/20/30 Additives minutes [%] Example 7 in accordance 0.25% sodium ferulate 86/73/66 with the invention and 0.25% DSDTP Example 8 in accordance 0.25% sodium ferulate 86/73/60 with the invention and 0.25% phosphite DSDTP = distearyl thiodipropionate Phosphit = Tris-(2,4-di-tert-butylphenyl)phosphit

[0151] The additives in accordance with the invention display a considerable stabilization effect since a smaller reduction of the polymer takes place over the trial period.

C) Oxidation Induction Time (OIT)

[0152] The oxidation induction time is a standardized test that is carried out in a differential calorimeter. This method permits a determination of the thermal stability of the material to be inspected. The time between the melting and the start of the degradation under isothermal conditions (220° C. here) is determined here. A nitrogen atmosphere is present here up to the melting of the material to be checked; synthetic air is subsequently supplied. In Table 4, the additive combinations incorporated and checked in commercial polypropylene (Moplen HP 500N, Lyondell Basell Industries) by means of a corotating twin screw laboratory extruder (Process 11, Thermo Fisher Scientific) at an extrusion temperature of 200° C. are summarized.

TABLE-US-00005 TABLE 4 Oxidation induction time of the compounds incorporated in polypropylene. OIT.sub.1 OIT.sub.2 OIT Additive combinations [min] [min] [min] Comparison example 5.21 4.59 4.90 Without additive Example in accordance 18.56 24.92 21.74 with the invention 0.50% sodium ferulate

[0153] It is shown that a considerable increase of the oxidative stability of polypropylene is achieved by the addition of 0.5% sodium ferulate.