3-phenyl-benzofuran-2-one diphosphate derivatives as stabilizers

Abstract

The invention relates to a composition comprising an organic material susceptible to oxidative, thermal or light-induced degradation and a compound of formula I-P, I-O or I-M. Further embodiments are a compound of formula I-P, I-O or I-M, a process for protection of the organic material by the compound, the use of the compound against degradation of the organic material, an additive composition comprising the compound, processes for manufacturing the compound and an intermediate involved therein. ##STR00001##

Claims

1. A composition, comprising: a) an organic material susceptible to oxidative, thermal or light-induced degradation, and b) a compound of formula I-P, I-O or I-M ##STR00044## wherein R.sup.IP represents one of the subformulae II-P, II-O or II-M ##STR00045## R.sup.1O represents one of the subformulae II-0 or II-M, or R.sup.IM represents the subformula II-M; R.sup.4, R.sup.5, R.sup.6 and R.sup.7 are independently from each other hydrogen or C.sub.1-C.sub.8-alkyl, R.sup.P2, R.sup.P3, R.sup.P5 and R.sup.P6 are independently from each other hydrogen or C.sub.1-C.sub.8-alkyl, R.sup.O1, R.sup.O2, R.sup.O5 and R.sup.O6 are independently from each other hydrogen or C.sub.1-C.sub.8-alkyl, and R.sup.M1, R.sup.M3, R.sup.M5 and R.sup.M6 are independently from each other hydrogen or C.sub.1-C.sub.8-alkyl, wherein the composition has a change in yellowness index of 5.0 to 19.7 when pellets of the composition are passed five times through a single screw extruder under air at 240° C.

2. The composition according to claim 1, wherein the organic material is a polymer, an oligohydroxy compound, a wax, a fat or a mineral oil.

3. The composition according to claim 2, wherein the organic material is a polymer, which is a polyolefin or a copolymer thereof, a polystyrene or a copolymer thereof, a polyurethane or a copolymer thereof, a polyether, which is obtainable by the polymerization of an epoxide, an oxetane or a tetrahydrofuran, or a copolymer thereof, a polyester or a copolymer thereof, a polycarbonate or a copolymer thereof, a poly(vinyl chloride) or a copolymer thereof, a poly(vinylidene chloride) or a copolymer thereof, a polysulfone or a copolymer thereof, a poly(vinyl acetate) or a copolymer thereof, a poly(vinyl alcohol) or a copolymer thereof, a poly(vinyl acetal) or a copolymer thereof, or a polyamide or a copolymer thereof.

4. The composition according to claim 1, wherein R.sup.4 and R.sup.6 are hydrogen, R.sup.5 and R.sup.7 are independently from each other hydrogen or C.sub.1-C.sub.8-alkyl, R.sup.P2 and R.sup.P6 are independently from each other hydrogen or C.sub.1-alkyl, R.sup.P3 and R.sup.P5 are independently from each other hydrogen or C.sub.1-C.sub.4-alkyl, R.sup.O1 and R.sup.O6 are independently from each other hydrogen or C.sub.1-C.sub.8-alkyl, R.sup.O2 is hydrogen or C.sub.1-alkyl, R.sup.O5 is hydrogen or C.sub.1-C.sub.4-alkyl, R.sup.M1 is hydrogen or C.sub.1-alkyl, R.sup.M3 and R.sup.M5 are independently from each other hydrogen or C.sub.1-C.sub.4-alkyl, and R.sup.M6 is hydrogen or C.sub.1-C.sub.8-alkyl.

5. The composition according to claim 1, wherein the compound is of formula I-P or I-0, R.sup.1P represents one of the subformulae II-P or II-O, and R.sup.1O represents the subformula II-O.

6. The composition according to claim 1, further comprising a) a polymer, which is a polyolefine or a copolymer thereof or a polystyrene or a copolymer thereof, and b) the compound is of formula I-P or I-O, wherein R.sup.1P represents subformula II-P, R.sup.1O represents subformula II-O, R.sup.4 and R.sup.6 are hydrogen, R.sup.5 and R.sup.7 are independently from each other hydrogen or C.sub.1-C.sub.8-alkyl, R.sup.O1 is hydrogen or C.sub.1-C.sub.8-alkyl, R.sup.O2, R.sup.O5 and R.sup.O6 are hydrogen, R.sup.P2 and R.sup.P6 are hydrogen, and R.sup.P3 and R.sup.P5 are independently from each other hydrogen or C.sub.1-C.sub.4-alkyl.

7. The composition according to claim 1, comprising component b) in an amount of 0.0005% to 10% based on the weight of component a).

8. The composition according to claim 1, comprising as component c) a further additive.

9. The composition according to claim 8, comprising as component c) a further additive, which is a phosphite or phosphonite different to component b), an acid scavenger, a phenolic antioxidant or an aminic antioxidant.

10. The composition according to claim 9, comprising as component c) a phenolic antioxidant, which is an ester of p-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid.

11. The composition according to claim 8, comprising as component d) a second further additive, which is a phosphite or phosphonite different to component b), an acid scavenger, a phenolic antioxidant or an aminic antioxidant; with the proviso that component d) is a different compound than component c).

12. A process for protection of an organic material susceptible to oxidative, thermal or light-induced degradation, comprising: providing the organic material, and incorporating into or applying onto the provided organic material a compound of formula I-P, I-O or I-M as defined in claim 1, wherein the composition has a change in yellowness index of 5.0 to 19.7 when pellets of the composition are passed five times through a single screw extruder under air at 240° C.

13. The process according to claim 12, wherein the organic material is a polymer, wherein the incorporating into the polymer takes place and a part or the complete incorporating takes place at a temperature between 135° C. to 350° C.

14. A method of using a compound of formula I-P, I-O or I-M as defined in claim 1 for stabilizing an organic material susceptible to oxidative, thermal or light-induced degradation against degradation by oxidation, heat or light, the method comprising: combining the compound of formula I-P, I-O or I-M with the organic material.

Description

SYNTHETIC EXAMPLES

(1) The synthetic procedures are conducted under a nitrogen atmosphere.

(2) If not otherwise stated, the starting materials are commercially available, for example from Aldrich Corp.

Example S-1: Synthesis of Compound (102)

(3) ##STR00035##
5.0 g (15 mmol) of compound (202) (obtainable according to EP 2500341 A, page 8, example 1 by using the corresponding 4-tert-octyl-phenol) are dissolved in 40 mL of dry dichloroethane at 65° C. To the solution are first added 1.41 g (18 mmol) of dry pyridine and then within 25 min 1.96 g (7 mmol) of compound (301) (3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, obtainable according to Lucas et al., Tetrahedron Lett. 2005, 46, 3347). The reaction mass is stirred under reflux for 3 h, cooled to room temperature and filtrated. After removal of solvent, a glassy residue is obtained which is further dried at 70° C. under vacuum. 5.3 g (69% of theory) of compound (102) as an amorphous solid are obtained.

(4) .sup.31P-NMR (toluene-d.sub.8): 116 ppm

(5) .sup.1H-NMR (toluene-d.sub.8): 4.3 ppm (s, 2H, CH at lactone-ring)

(6) MS (LC/MS, ACPI positive mode): [M+1].sup.+=1094

Example S-2: Synthesis of Compound (103)

(7) ##STR00036##

(8) Compound (103) is prepared in analogy to example S-1 from compound (203) (obtainable according to EP 0648765 A, page 30, compound 115) and obtained in a yield of 81% of theory as an amorphous solid.

(9) .sup.31P-NMR (toluene-d.sub.8): 122 ppm

(10) .sup.1H-NMR (toluene-d.sub.8): 4.3 ppm (s, 2H, CH at lactone-ring)

(11) MS (LC/MS, ACPI positive mode): [M+1].sup.+=926

Example S-3a: Synthesis of Compound (402) with m-Perchlorobenzoic Acid

(12) ##STR00037##
3.0 g (3.0 mmol) of compound (102) are dissolved in 40 mL of dry dichloromethane and the solution is cooled to 5° C. 1.0 g (6 mmol) of m-chloroperbenzoic acid are added in 2 portions. A yellowish precipitate is formed, which slowly dissolves again. The solution is stirred for 3 h at 5° C. After removal of the solvent, the solid residue is purified by flash chromatography (SiO.sub.2, heptane/ethyl acetate 9:1). 2.7 g (89% of theory) of compound (402) are obtained as a colorless amorphous solid.

(13) .sup.31P-NMR (DCM-d.sub.2): −15.1 ppm

(14) .sup.1H-NMR (DCM-d.sub.2): 4.75 ppm (s, 2H, lactone-H)

(15) MS (LC/MS, ACPI positive mode): [M+H].sup.+=1125

Example S-3b: Synthesis of Compound (402) with Hydrogen Peroxide

(16) ##STR00038##

(17) 2.7 g (2.5 mmol) of compound (102) are dissolved in 25 mL of acetonitrile, the solution is cooled to 5° C. and 5 mL of 10% aqueous hydrogen peroxide (15 mmol) are added at this temperature. After appearance of an emulsion-like reaction mass a waxy product precipitates, which is filtered off after 6 h of stirring and re-dissolved in 80 mL ethyl acetate. After treating this solution 2 times with 50 mL of an aqueous solution of 20% NaHSO.sub.3, the organic phase is washed with 50 mL brine and dried over Na.sub.2SO.sub.4. After removing the solvent, 2.2 g (91% of theory) of compound (402) is obtained in pure form as a colorless amorphous solid.

(18) Analytical data as stated at example S-3a.

Example S-3c: Synthesis of Compound (402) by Condensation with Compound (501)

(19) ##STR00039##

(20) 7.8 g (26 mmol) of compound (501), which is prepared by reaction of pentaerythritol with phosphoryl chloride (═POCl.sub.3) as described in Polymer Degradation and Stability, 2015, 113, p. 86-94, are dissolved in 100 mL of dry acetonitrile at room temperature. 24.5 g (53 mmol) of compound (202) are added in 3 portions. A suspension is formed. 8.0 mL (57 mmol) triethylamine are added dropwise. After heating under reflux for 16 h, the reaction mass is cooled to room temperature. The precipitated solids are filtered off and washed with 250 mL of water. After final washing with 150 mL acetonitrile at 0° C., the product is dried at 60° C. under vacuum. 17.3 g (59% of theory) of compound (402) is obtained as a colorless amorphous solid.

(21) Analytical data as stated in example S-3a.

Example S-4a: Synthesis of Compound (403) with m-Perchlorobenzoic Acid

(22) ##STR00040##

(23) 5.02 g (5 mmol) of compound (103) are dissolved in 30 mL of dry dichloromethane and the solution is cooled to 5° C. 2.62 g of 70% m-chloroperbenzoic acid (10 mmol) are added in 2 portions. A colorless precipitate is formed. The suspension is stirred for 3 h at 5° C. The precipitate is filtered off and washed with additional 100 mL of dichloromethane. The combined filtrates are evaporated to dryness and the solid residue is purified by flash chromatography (SiO.sub.2, heptane/ethyl acetate 9:1). 1.4 g (27% of theory) of compound (403) are obtained as a colorless amorphous solid.

(24) .sup.31P-NMR (DCM-d.sub.2): −12.9 ppm

(25) .sup.1H-NMR (DCM-d.sub.2): 4.82 ppm (s, 2H, lactone-H)

(26) MS (LC/MS, positive mode): [M+H].sup.+=958

Example S-4b: Synthesis of Compound (403) with Hydrogen Peroxide

(27) ##STR00041##

(28) 6.8 g (6.7 mmol) of compound (103) are dissolved in 60 mL of acetonitrile and 15 mL of 10% hydrogen peroxide (45 mmol) are added at room temperature. The mixture is heated to 40° C. and stirred at this temperature for 150 min. After cooling to 20° C., the reaction mass is added to 100 mL water of 0° C., the precipitated product is filtered off and dissolved in 100 mL ethyl acetate. After treating this solution two times with 50 mL of an aqueous solution of 20% NaHSO.sub.3, the organic phase is washed with 100 mL. brine and dried over Na.sub.2SO.sub.4. After removing the solvent, the product is purified by flash chromatography (SiO.sub.2, heptane/ethyl acetate 9:1). 5.0 g (72% of theory) of compound (403) are obtained as a colorless amorphous solid. Analytical data as in example S-4a.

APPLICATION EXAMPLES

(29) The following known stabilizers are partly employed in addition to the inventive compounds:

(30) AO-1 is Irganox 1010 (RTM BASF), which contains pentaerythritol tetrakisβ-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate).

(31) AO-2 is Irganox 1076 (RTM BASF), which contains stearyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

(32) Phos-1 is Irgafos 168 (RTM BASF), which contains tris(2,4-di-tert-butylphenyl) phosphite.

(33) CaSt is commercially available calcium stearate, which acts as an acid scavenger.

(34) For polymer processing at example A-1, the polymer of interest in granular form is blended with various additives according to the recipe of the formulation as stated at the respective table. The blending is carried out using Henschel, Turbula or Kitchen-Aid mixers. The thoroughly blended formulations are then melt compounded in a twin-screw extruder at lower temperature (210° C. [410° F.]) under nitrogen. This ensures good melt mixing with minimal damage to the polymer due to oxidative degradation. A zero pass extrudate is obtained, which is denoted in the examples as the zero-pass extrusion.

(35) The resultant zero pass extrudate at example A-1 is then extruded multiple times a single screw extruder, fitted with a Maddock mixing section, at higher temperature (260° C. [500° F.]) and open to air. Extrusion at higher temperatures in combination with the presence of oxygen (air) enhance the rate of polymer degradation. These aggressive extrusion conditions put a strain on the stabilization system, which allows for differentiation by various testing. This multiple pass extrusion indicates processing stability. Pelletized samples of zero, first, third and fifth pass extrudate are collected and stored in sealed plastic bags at room temperature in storage boxes in the dark.

(36) Melt flow rates of a samples at example A-1 are tested for retention of molecular mass (weight). This is measured by melt flow rate retention (according to ASTM-1238) on a Tinius-Olsen extrusion plastometer. For a polypropylene, the test conditions are 230° C. and 2.16 kg. Melt flow rates are measured in grams of polymer that flow out of a defined orifice in 10 minutes or decigrams/minute.

(37) Oven aging of a sample at example A-1 is tested for oxidative stability below the melting point of the polymer and indicates post extrusion long term thermal stability. Warming below the melting point of the polymer accelerates polymer degradation. Oven aging is done by putting compression molded plaques (1 mm [40 mils]) in a Blue M forced draft oven equipped with a rotating carousel in order to homogenize the exposure to elevated temperatures (130° C., 150° C.) inside the oven. Failure is measured by days to embrittlement by bending the plaque every 3 to 4 days until the plaque snapped due to oxidative degradation. The time is measured in days.

(38) Oxidative induction time (OIT) at example A-1 is tested for oxidative stability above the melting point of the polymer and indicates post extrusion thermal stability. Oxidative induction time (OIT) is a means of measuring the activity of the stabilizer in the polymer melt at high temperatures (190° C.) and an oxidative environment (oxygen). The experiment is run on a differential scanning calorimeter (DSC). A scan is collected using a heating rate of 10° C./min under nitrogen from 50° C. to 190° C., then switching to oxygen and holding at isothermal conditions until catastrophic oxidation. Time to onset of catastrophic oxidation (observed as a strong exotherm) is measured in minutes. The sample is tested in the form of a film with a thickness of 0.25 mm (10 mils).

(39) Yellowness Index (Yl) at example A-2 is tested for color change and is measured according to DIN 6167.

Example A-1: Stabilization of a Polypropylene Homopolymer

(40) A commercially available molding grade Ziegler-Natta polypropylene (zn-PP-homopolymer) with a melt flow rate of 12 dg/min from a bulk/slurry phase polymerization process, which is essentially free of any stabilization additives, is processed and evaluated as described in table A-1.

(41) TABLE-US-00001 TABLE A-1 composition No. 1 .sup.a) 2 .sup.a) 3 .sup.a) 4 .sup.b) 5 .sup.b) zn-PP-homopolymer 99.99 99.85 99.80 99.8468 99.8675 CaSt 0.050 0.050 0.050 0.050 0.050 AO-1 0.050 0.050 0.050 0.050 0.050 Phos-1 — 0.050 0.100 0.0407 0.022 compound (403) — — — 0.0125 — compound (402) — — — — 0.0105 total additives content 0.100 0.150 0.200 0.1532 0.1325 phosphorus (III) .sup.c) — 0.0024 0.0048 0.0020 0.0011 260° C. (500° F.) melt processing melt flow rates zero pass 22.55 15.70 15.06 15.73 16.04 1.sup.st pass 33.90 19.71 17.11 17.74 17.15 3.sup.rd pass 51.52 25.66 20.09 19.68 18.44 5.sup.th pass 66.92 30.88 22.32 22.33 20.58 5.sup.th pass less zero 44.38 15.19 7.26 6.60 4.54 pass oven ageing zero pass/135° C. 18 71 86 86 71 zero pass/150° C. 2 14 21 18 13 Oxidative induction time zero pass/190° C. 4 15 33 20 18 Footnotes: .sup.a) reference .sup.b) inventive .sup.c) calculated based on phosphorus (III) [=P(III)] provided by Phos-1 (4.8 parts by weight P(III) based on 100 parts of tris(2,4-di-tert-butylphenyl) phosphite; 100% content assumed) and based on no contribution by compound (402) (5.5 parts by weight P(V) based on 100 parts of compound (402); 100% content assumed) or by compound (403) (6.5 parts by weight P(V) based on 100 parts of compound (403); 100% content assumed)

(42) The data of table A-1 show that (i) a three-component mixture comprising compound (403) or compound (402) keep melt flow rates during processing more stable than a two-component mixture without compound (403) or compound (402) at a comparable overall additives content and even at a clearly lowered overall additives content; (ii) a three-component mixture including compound (403) or compound (402) shows oven aging values and oxidation induction time values comparable to a two-component mixture without compound (403) or compound (402) at a comparable overall additive content; (iii) the findings of (i) and (ii) are obtained despite of a reduced content of phosphorous (III), which is said to act as stabilizing group by its reacting with oxygen to phosphorous (V), e.g. from a phosphite to a phosphate; particularly the findings of (ii) are obtained in long term exposure to air containing oxygen at oven aging or at exposure to pure oxygen at oxidation induction time.

Example A-2: Stabilization of a Linear Low-Density Polyethylene

(43) A commercially available linear low-density polyethylene (LL 6130 AP from BP Chemicals, linear LDPE) in form of a polymer powder is mixed with the stabilizers as provided in table A-2 in a highspeed mixer (Mixaco Lab CM2). The obtained mixture in powder form is compounded in a twin-screw extruder (Collin 25/42 D) at 210° C. under a nitrogen blanket and pelletized. The processing stability of these pellets is investigated via multiple pass extrusion under air with a single screw extruder at 240° C. Pellets after the first pass extrusion, third pass extrusion and fifth pass extrusion are compression-molded to 2 mm plaques and the yellowness index is measured. Results are depicted in table A-2.

(44) TABLE-US-00002 composition No. 2-1 .sup.a) 2-2 .sup.b) 2-3 .sup.a) 2-4 .sup.b) LL6163 AP (lin. LD-PE) 99.85 99.85 99.85 99.85 CaSt 0.050 0.050 0.050 0.050 AO-2 — — 0.030 0.030 compound (403) — 0.100 — 0.070 compound (103) 0.100 — 0.070 — total additives content 0.150 0.150 0.150 0.150 phosphorus (III) .sup.c) 0.0067 — 0.0047 — 240° C. melt processing yellowness index zero pass 41.5 81.3 51.3 81.6 1.sup.st pass 56.6 90.1 68.1 90.2 3.sup.rd pass 70.1 94.0 70.1 95.4 5.sup.th pass 76.3 95.1 87.7 97.5 delta yellowness index 19.7 5.0 19.6 7.3 1.sup.st pass vs 5.sup.th pass Footnotes: .sup.a) reference .sup.b) inventive .sup.c) calculated based on phosphorus (III) [=P(III)] provided by compound (103) (6.7 parts by weight P(III) based on 100 parts of compound (103); 100% content assumed) and based on no contribution by compound (403) (6.5 parts by weight P(V) based on 100 parts of compound (403); 100% content assumed)

(45) The data of table A-2 show that (i) compound (403) provides a slower increase of yellowness index than compound (103), i.e. a less changing yellowness index respectively less change of the initial color after compounding; (ii) compound (403) in combination with AO-2 provides a more stable yellowness index than compound (103) in combination with AO-2, i.e. a less changing yellowness index respectively less change of the initial color after compounding.

Example H-1: Hydrolytic Stability of Compound (402) and Compound (403)

(46) Hydrolysis testing: A sample is tested for hydrolytic stability using a forced draft humidity oven with the proper adjustments to maintain 50° C. (122° F.) and 80% relative humidity. The test method involves putting 0.5 grams of the material to be tested in properly labeled glass vials, uncapped. For the present testing, several sets of vials are provided and the samples are removed from the humidity oven every few days. The exposed sample is then tested for the extent of hydrolysis by High Pressure Liquid Chromatography (HPLC), which measures the retention of intact starting material as well as transformation chemistry. The increase of the presence of a hydrolysis product is used as an indicator for loss of intact starting material.

(47) Compound (402) and compound (102) are tested for hydrolysis by observation of the generation of content of compound (202) via the hydrolysis reaction.

(48) ##STR00042##

(49) Compound (403) and compound (103) are tested for hydrolysis by observation of the generation of content of compound (203) via the hydrolysis reaction.

(50) ##STR00043##
Sample H-1-I: compound (402) in the form of a white powder after 61 days, the sample H-1-I is still a free-flowing white material
Sample H-1-II: compound (102) in the form of white powder after 10 days, the sample H-1-II is waxy to the touch and less free-flowing
Sample H-1-III: compound (403) in the form of a white powder after 61 days, the sample H-1-III is still a free-flowing white material
Sample H-1-IV: compound (103) in the form of a white powder (with 5% already liberated lactone moiety due to hydrolysis despite of a previous storage in a dry desiccator at 20° C.; this hydrolytic instability would require some type of hydrolysis inhibitor such as the well-known tri-isopropanol amine) after 7 days, the sample H-1-IV is waxy to the touch and less free-flowing

(51) TABLE-US-00003 TABLE H-1-1 Sample No. time of H-1-I .sup.b) H-1-II .sup.a) H-1-III .sup.b) H-1-IV .sup.a) exposure content of compound (202) .sup.c) content of compound (203) .sup.c) [days] [area %] [area %] 0 1.1 0.2 0.0  5.0 3 1.1 0.4 0.0 — 4 — — 0.0  6.1 5 1.1 0.6 0.0 — 7 — — 0.0 13.0 10 — 9.9 0.0 43.7 14 1.0 100 0.1 — 15 — — — 90.0 30 1.1 — 0.2 — 45 1.0 — 0.2 — 61 0.9 — 0.2 — Footnotes: .sup.a) reference .sup.b) inventive .sup.c) the content of compound (202) or compound (203) refers to the percent of liberated lactone moiety as a consequence of the hydrolysis reaction. The analytical method (HPLC) is evaluated so that it corrects for the absorption coefficient for each of the starting products, as well as the products that are generated by the hydrolysis reaction. Accordingly, 100% hydrolysis refers to 100% of the potential lactone moiety that could be liberated is actually liberated

(52) All tested samples except for compound (103) start out intact with less than or around 1% of compound (202) respectively compound (203). After 14 days, compound (102) is failed and after 15 days, compound (103) is essentially failed. In comparison, there is virtually no hydrolysis of compound (402) or compound (403). It is preferred that hydrolysis is reduced and the tested sample remains a free-flowing white material. This illustrates the advantage of a compound of formula I-P, formula I-O or formula I-M as a class of powerful melt processing stabilizers with remarkable hydrolytic stability.