USE OF SUBSTITUTED CINNAMIC ACID ESTERS AS STABILISERS FOR ORGANIC MATERIALS, STABILISED ORGANIC MATERIAL, METHOD FOR STABILISING ORGANIC MATERIALS AND SPECIFIC CINNAMIC ACID ESTERS

Abstract

The present invention relates to the use of specific cinnamic acid esters as stabilizers of organic materials, in particular against oxidative, thermal and/or actinic degradation. The invention also relates to a corresponding stabilized organic material. The invention further relates to a method for stabilizing organic materials, in which specific cinnamic acid esters are incorporated into the organic material. According to the invention, specific new cinnamic acid esters are also disclosed.

Claims

1-15. (canceled)

16. A method of stabilizing an organic material comprising combining the organic material with a compound or mixtures of a plurality of compounds according to general Formula I ##STR00041## where R.sup.1, R.sup.2 and R.sup.3 are each independently selected 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 moieties R.sup.1, R.sup.2 and R.sup.3 is a hydroxy moiety and/or a linear or branched alkoxy group having 1 to 6 carbon atoms, and R.sup.4 is selected from the group consisting of a linear or branched alkyl moieties having at least 8 carbon atoms and the following moieties according to Formulas IIa, IIb and IIc, ##STR00042## where R.sup.5 is the same or different at each occurrence and is selected from the group consisting of hydroxy and the following moiety according to Formula III ##STR00043## where R.sup.1, R.sup.2 and R.sup.3 are as defined above.

17. The method according to claim 16, wherein the organic material is selected from the group consisting of plastics, coatings, lubricants, hydraulic oils, engine oils, turbine oils, gear oils, metalworking fluids, chemicals, and monomers.

18. The method according to claim 16, wherein the compound according to general Formula I is selected from the following compounds: ##STR00044##

19. The method according to claim 16, wherein the linear or branched alkyl moiety having at least 8 carbon atoms of the moiety R.sup.4 is derived from alcohols selected from the group consisting of octan-1-ol, nonan-1-ol, decan-1-ol, undecan-1-ol, lauryl alcohol, tridecane-1-ol, myristyl alcohol, cetyl alcohol, stearyl alcohol, ceryl alcohol, myricyl alcohol, palmitoleyl alcohol, oleyl alcohol, arachidyl alcohol, behenyl alcohol, erucyl alcohol, lignoceryl alcohol, montanyl alcohol, linoleyl alcohol, isotridecyl alcohol, geraniol, rhodinool, citronellol and cerol.

20. The method according to claim 16, wherein R.sup.5 is selected from the following moieties ##STR00045##

21. The method according to claim 16, wherein the substitution pattern of the moiety according to ##STR00046## of the compound according to Formula I and the substitution pattern of the moiety R.sup.5 are the same.

22. The method according to claim 16, wherein the compound according to general Formula I, or in the case of a mixture of a plurality of compounds according to general Formula I, all of the compounds according to general Formula I, is contained in the organic material in a proportion by weight of 0.01 to 10.00% by weight.

23. The method according to claim 16, wherein the plastic is selected from the group consisting of a) polymers from olefins or diolefins, natural rubber (NR), polycyclooctene, polyalkylene-carbon monoxide copolymers, copolymers of polypropylene-polyethylene (EP), EPM or EPDM with 5-ethylidene-2-norbornene as a comonomer, ethylene-vinyl acetate (EVA}, ethylene acrylic esters, ethylene acrylic acid glycidyl(meth)acrylate, polypropylene graft maleic anhydride, polypropylene graft acrylic acid, polyethylene graft-acrylic acid, polyethylene-polybutylacrylate-graft-maleic anhydride, and long-chain branched polypropylene copolymers which are produced with alpha-olefins as comonomers, b) polystyrene, polymethylstyrene, poly-alpha-methyl styrene, 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, graft copolymers made of methyl methacrylate, styrene-butadiene and ABS (MABS), and hydrogenated polystyrene derivatives, c) halogen-containing polymers, d) polymers of unsaturated esters, polyacrylonitrile, polyacrylamide, and copolymers of acrylonitrile and alkyl acrylate, e) polymers of unsaturated alcohols and derivatives, f) polyacetals and blends with polystyrene or polyamides, g) polymers of cyclic ethers, h) polyurethanes and polyureas, i) polyamides, blends of different polyamides and blends of polyamides with polyolefins, j) polyimides, polyamide-imides, polyetherimides, polyesterimides, poly(ether)ketones, polysulfones, polyethersulfones, polyarylsulfones, polyphenylene sulfides, polybenzimidazoles, and polyhydantoins, k) polyesters made from aliphatic or aromatic dicarboxylic acids and diols or from hydroxycarboxylic acids, l) polycarbonates, polyester carbonates, and blends, m) cellulose derivatives, n) epoxy resins, o) phenolic resins, p) unsaturated polyester resins from unsaturated dicarboxylic acids and diols with vinyl compounds, q) silicones, and r) mixtures, combinations or blends of two or more of the aforementioned polymers.

24. The method according to claim 16, wherein the plastic comprises at least one additional additive selected from the group consisting of primary and/or secondary antioxidants.

25. The method according claim 24, wherein the primary and/or secondary antioxidants are selected from the group consisting of phosphites, phosphonites, thiols, phenolic antioxidants, sterically hindered amines, hydroxylamines and mixtures or combinations thereof, UV absorbers, light stabilizers, hydroxylamine-based stabilizers, benzofuranone-based stabilizers, nucleating agents, impact modifiers, plasticizers, lubricants, rheology modifiers, chain extenders, processing aids, pigments, dyes, optical brighteners, antimicrobial agents, antistatic agents, slip agents, antiblocking agents, coupling agents, dispersants, compatibilizers, oxygen scavengers, acid scavengers, co-stabilizers, marking agents, and anti-fogging agents.

26. The method according to claim 24, wherein the at least one additional additive is contained or added in an amount of 0.01 to 9.99% by weight based on the total of the at least one compound according to Formula I, the organic material, and the at least one additive.

27. A stabilized organic material comprising at least one compound according to general Formula I, or a mixture of a plurality of compounds according to general Formula I, as a stabilizer ##STR00047## wherein R.sup.1, R.sup.2 and R.sup.3 are each independently selected 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 moieties R.sup.1, R.sup.2 and R.sup.3 is a hydroxy moiety and/or a linear or branched alkoxy group having 1 to 6 carbon atoms, and R.sup.4 is selected from the group consisting of a linear or branched alkyl moieties having at least 8 carbon atoms and the following moieties according to Formulas IIa, IIb and IIc, ##STR00048## where R.sup.5 is the same or different at each occurrence and is selected from the group consisting of hydroxy and the following moiety according to Formula III ##STR00049## where R.sup.1, R.sup.2 and R.sup.3 are as defined above.

28. The organic material according claim 27, having the following composition: 0.01 to 10.00% by weight of a compound according to general Formula I, or, in the case of a mixture of a plurality of compounds according to general Formula I, the entirety of all compounds according to general Formula I, 99.99 to 90.00% by weight of at least one organic material, and 0 to 9.99% by weight of at least one additive, the components adding up to 100% by weight.

29. The organic material according to claim 28, wherein the at least one additive is selected from the group consisting of primary and/or secondary antioxidants, UV absorbers, light stabilizers, hydroxylamine-based stabilizers, benzofuranone-based stabilizers, nucleating agents, impact modifiers, plasticizers, lubricants, rheology modifiers, chain extenders, processing aids, pigments, dyes, optical brighteners, antimicrobial agents, antistatic agents, slip agents, antiblocking agents, coupling agents, dispersants, compatibilizers, oxygen scavengers, acid scavengers, co-stabilizers, marking agents and anti-fogging agents.

30. A compound according to the general Formula I ##STR00050## where R.sup.1, R.sup.2 and R.sup.3 are each independently selected 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 moieties R.sup.1, R.sup.2 and R.sup.3 is a hydroxy moiety and/or a linear or branched alkoxy group having 1 to 6 carbon atoms, and R.sup.4 is selected from the group consisting of the following moieties according to Formulas IIa, IIb and IIc ##STR00051## where R.sup.5 is the same or different at each occurrence and is selected from the group consisting of hydroxy and the following moiety according to Formula III ##STR00052## wherein R.sup.1, R.sup.2 and R.sup.3 are as defined above.

Description

EMBODIMENTS

[0129] A) Preparation of the Hydroxycinnamic Acid Salts According to the Invention

[0130] A1) Synthesis of the Methyl Ferulate

##STR00038##

[0131] In a 500 mL round bottom flask, 15 g (1.00 eq., 77.24 mmol) ferulic acid are dissolved in 300 mL (95.77 eq., 237.00 g, 7397.00 mmol) methanol with gentle heating. Then 3.1 mL (0.75 eq., 57.99 mmol) of 95% sulfuric acid are added, the solution turning yellow. The solution is heated at 70° C. for 3 h and, after cooling, is added to 375 mL of chloroform. The solution is then washed twice with 300 mL distilled water each and once with a saturated sodium bicarbonate solution. The organic phase is dried over 100 g of sodium sulfate and the chloroform is then distilled off. After drying under high vacuum, 14.03 g (67.39 mmol) of a white solid are obtained. The yield is 87.25%.

[0132] A2) Synthesis of the Octadecyl Ferulate

##STR00039##

[0133] First 3.00 g (1.00 eq, 14.41 mmol) of methyl ferulate and 4.68 g (1.20 eq., 17.30 mmol) of stearyl alcohol are placed in a heated 100 mL round bottom flask fitted with a condensation bridge and cold trap in a countercurrent of nitrogen. The reaction mixture is melted at 95° C. with gentle stirring under an inert nitrogen atmosphere. 0.15 g (0.04 eq., 0.60 mmol) dibutyltin oxide (DBTO) are added to the clear melt in a nitrogen countercurrent. The reaction temperature is increased to 140° C. and a pressure of between 200-800 mbar is set. After a reaction time of 24 h, the excess stearyl alcohol is condensed off by increasing the temperature to 155° C. and reducing the pressure to 1×10-3 bar. The vacuum is broken by feeding in nitrogen and the slightly yellowish reaction melt is cooled to room temperature. This is then taken up in dichloromethane, treated with 2.80 g fuller's earth (OPTIMUM 21OFF) and refluxed for 30 min. After filtration through a short silica pad, the solvent is distilled off in vacuo. 4.11 g (9.20 mmol, 64.84%) of the white solid remain.

[0134] A3) Synthesis of the Pentaerythritol Ester of Ferulic Acid

##STR00040##

[0135] 2.00 g (1.00 eq., 14.69 mmol) of pentaerythritol and 12.85 g (4.20 eq., 61.76 mmol) of ferulic acid methyl ester are initially introduced in a nitrogen countercurrent into a heated 100 ml round bottom flask fitted with a condensation bridge and cold trap. The reaction mixture is melted at 100° C. with gentle stirring under an inert nitrogen atmosphere. 0.18 g (0.05 eq., 0.72 mmol) dibutyltin oxide (DBTO) are added to the clear melt in a nitrogen countercurrent. The reaction temperature is increased to 170° C. and a pressure of between 600-800 mbar is set. After a reaction time of 27 h, the excess ferulic acid methyl ester is condensed off by setting the temperature to 155° C. and reducing the pressure to 1×10-3 bar. The vacuum is broken by feeding in nitrogen and the yellow reaction melt is cooled to room temperature. This is then taken up in dichloromethane, treated with 2.80 g fuller's earth (OPTIMUM 21OFF) and refluxed for 30 min. After filtration through a short silica pad, the solvent is distilled off in vacuo. 10.02 g (11.92 mmol, 81.12%) of the finely powdered, yellow solid remain.

[0136] B) Application Check

[0137] 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 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 decrease, the higher the stabilization effect.

TABLE-US-00001 TABLE 1 Stabilization of polypropylene Residual strength after 10/20/30 minutes [%], mean Additive values from 2 tests Comparison Without additive 63/39/26 example 1 Example 1 in 0.5% octadecyl 80/72/62 accordance with ferulate the invention Example 2 in % pentaerythritol 73/57/44 accordance with tetra the invention ferulate Example 3 in 0.25% octadecyl 80/70/60 accordance with ferulate + the invention 0.25% erythritol Example 4 in 0.25% 77/64/52 accordance with Octadecylferulate + the invention 0.25% DSDTP Example 5 in 0.25% pentaerythritol 72/58/47 accordance with tetraferulate + the invention 0.25% DSDTP Example 6 in 0.25% octadecyl 80/65/54 accordance with ferulate + the invention 0.25% phosphite Example 7 in 0.25% pentaerythritol 80/62/42 accordance with tetraferulate + the invention 0.25% phosphite DSDTP = distearyl thiodipropionate phosphite = Tris-(2,4-di-tert-butylphenyl)phosphite

[0138] The additives according to the invention show a clear stabilizing effect, since there is less degradation of the polymer over the course of the test.