Oxygen scavenging plastic material

Abstract

The invention relates to a polyether-polyester copolymer comprising: (i) polyether segments wherein at least one polyether segment contains at least one polytetramethylene oxide segment, (ii) polyester segments, (iii) bridging elements of the structure —CO—R2-CO—, wherein R2 represents an optionally substituted bivalent hydrocarbon residue consisting of 1 to 100 carbon atoms; (iv) one or two end-caps R1-O—(C.sub.2-C.sub.4—O—).sub.e—*, wherein R1 is an optionally substituted hydrocarbon residue and e is an integer of from 0 to 1000.

Claims

1. A polyether-polyester copolymer comprising (i) polyether segments wherein at least one polyether segment contains at least one polytetramethylene oxide segment; (ii) polyester segments; (iii) bridging elements of the structure —CO—R2-CO—, wherein R2 is an optionally substituted bivalent hydrocarbon residue including 1 to 100 carbon atoms; and (iv) one or two end-caps R1-O—(C.sub.2-C.sub.4—O—).sub.e—*, wherein R1 is an optionally substituted hydrocarbon residue, (C.sub.2-C.sub.4-O—) represents the same or different C.sub.2-C.sub.4-O repeating unit including 2 to 4 carbon atoms, and e is an integer of from 0 to 1000, wherein the mass ratio Θ defined as the mass ratio between the endcap content and the overall content of all dicarbonyl structure elements (ii) and (iii) is between 0.001 and 100.

2. The polyether-polyester copolymer as claimed in claim 1, wherein the polyether segments (i) contain ethylene oxide segments, propylene oxide segments or a combination thereof.

3. The polyether-polyester copolymer as claimed in claim 1, wherein the polyester segments (ii) are represented by formula (II): ##STR00010## wherein represents a bond to a bridging element (iii), R2 and R3 independently of each other are an optionally substituted hydrocarbon residue including 1 to 100 carbon atoms, and u is an integer between 1 and 50.

4. The polyether-polyester copolymer as claimed in claim 1, wherein bridging elements are described by formula (III) ##STR00011## wherein R2 represents an optionally substituted hydrocarbon residue including 1 to 100 carbon atoms.

5. The polyether-polyester copolymer as claimed in claim 1, wherein end-caps are described by the following general formula
R1-O—(C.sub.2-C.sub.4—O—).sub.e—*, wherein R1 is an aliphatic hydrocarbon residue of 1 to 24 carbon atoms, an olefinic hydrocarbon residue of 2 to 24 carbon atoms, or an aromatic hydrocarbon residue of 6 to 14 carbon atoms, wherein said hydrocarbon residues are optionally substituted with C.sub.1-C.sub.5-alkoxy, nitro, cyano, sulfo, or a combination thereof, and wherein e is an integer of between 0 and 500.

6. The polyether-polyester copolymer as claimed in claim 1, wherein R1-O—(C.sub.2-C.sub.4—O—).sub.e—* corresponds to the following formulae ##STR00012## wherein the different monomers of the formulae are randomly distributed, in blocks, or a combination of randomly distributed and block, and b is an integer between 0 and 250, a is an integer between 0 and 250, c is an integer between 0 and 70, and the sum a+b+c is of from 0 to 570; wherein R1 is an aliphatic hydrocarbon residue of 1 to 24 carbon atoms, an olefinic hydrocarbon residue of 2 to 24 carbon atoms, or an aromatic hydrocarbon residue of 6 to 14 carbon atoms, wherein said hydrocarbon residues are optionally substituted with C.sub.1-C.sub.5-alkoxy, nitro, cyano, sulfo, or a combination thereof.

7. The polyether-polyester copolymer as claimed in claim 1, wherein R1 is methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, tert-butyl, n-pentyl, iso-pentyl, sec-pentyl, neo-pentyl, 1,2-dimethylpropyl, iso-amyl, n-hexyl, sec-hexyl, n-heptyl, n-octyl, 2-ethyl-hexyl, n-nonyl, n-decyl, tridecyl, isotridecyl, tetradecyl, hexadecyl, octadecyl, methylphenyl cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, or cyclodecyl.

8. The polyether-polyester copolymer as claimed in claim 1, wherein the polyether-polyester copolymer has a number average molecular weight between 2000 and 1000000 g/mol.

9. The polyether-polyester copolymer as claimed in claim 1, wherein the mass ratio Ω defined as the mass ratio between the poly(tetramethyleneoxide) content and the overall content of all dicarbonyl structure elements (ii) and (iii) is between 0.1 and 10.

10. The polyether-polyester copolymer as claimed in claim 1, wherein the mass ratio Θ is between 0.005 and 50.

11. A method of preparing a polyether-polyester copolymer as claimed in claim 1 comprising polycondensation of (i) at least one polyether segment diol containing at least one polytetramethylenoxide segment, (ii) at least one polyester segment having dibasic acids, or anhydrides, (iii) at least one bridging element dibasic acids, or esters or anhydrides and (iv) at least one end-cap R1-O—(C.sub.2-C.sub.4—O—).sub.e—* having a hydroxy end group.

12. An active oxygen barrier composition comprising a polyether-polyester copolymer as claimed in claim 1 and a transition metal catalyst.

13. A plastic material comprising: a component a) which is a thermoplastic polymer; a component b) which is a polyether-polyester copolymer as claimed in claim 1; and a component c) which is a transition metal catalyst.

14. The plastic material as claimed in claim 13, which is a masterbatch, a compound or a formed article.

15. The plastic material as claimed in claim 13 which is or which is part of a container or a film.

16. A polyether-polyester copolymer comprising (i) polyether segments wherein at least one polyether segment contains at least one polytetramethylene oxide segment; (ii) polyester segments; (iii) bridging elements of the structure —CO-R2-CO—, wherein R2 is an optionally substituted bivalent hydrocarbon residue including 1 to 100 carbon atoms; and (iv) one or two end-caps R1-O—(C.sub.2-C.sub.4—O—).sub.e—*, wherein (C.sub.2-C.sub.4—O—) represents the same or different C.sub.2-C.sub.4—O repeating unit including 2 to 4 carbon atoms, and e is an integer of from 0 to 1000, and R1 is methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, tert-butyl, n-pentyl, iso-pentyl, sec-pentyl, neo-pentyl, 1,2-dimethylpropyl, iso-amyl, n-hexyl, sec-hexyl, n-heptyl, n-octyl, 2-ethyl-hexyl, n-nonyl, n-decyl, tridecyl, isotridecyl, tetradecyl, hexadecyl, octadecyl, methylphenyl cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, or cyclodecyl.

17. The polyether-polyester copolymer as claimed in claim 16, wherein the polyether segments (i) contain ethylene oxide segments, propylene oxide segments or a combination thereof.

18. The polyether-polyester copolymer as claimed in claim 16, wherein the polyester segments (ii) are represented by formula (II): ##STR00013## wherein represents a bond to a bridging element (iii), R2 and R3 independently of each other are an optionally substituted hydrocarbon residue including 1 to 100 carbon atoms, and u is an integer between 1 and 50.

19. The polyether-polyester copolymer as claimed in claim 16, wherein the mass ratio Θ defined as the mass ratio between the endcap content and the overall content of all dicarbonyl structure elements (ii) and (iii) is between 0.001 and 100.

20. An active oxygen barrier composition comprising a polyether-polyester copolymer as claimed in claim 16 and a transition metal catalyst.

Description

EXAMPLES

(1) % by weight mentioned in the following examples are based on the total weight of the mixture, composition or article; parts are parts by weight;

(2) “ex” means example; “cpex” means comparative example; MB means masterbatch; CO means compound, “D” means direct metering in the respective additives.

(3) Equipment Used

(4) The equipment used to perform the production tests of the PET cast film described below consisted of single screw extruder, screw diameter 25 mm 1 filter changer with 40 micron filter mesh 1 flat head die width 350 mm for producing a monolayer film 1 horizontal calender with 3 rollers
Substances Used
Component a: A1:

(5) Polyethylene terephthalate (PET) having a density from 1.35 to 1.45 g/cm.sup.3 and intrinsic viscosity from 0.74 to 0.78 dl/g (ASTM D3236-88).

(6) Component a: A2:

(7) Polybutylene terephthalate (PBT) having a density from 1.28 to 1.32 g/cm.sup.3 and intrinsic viscosity from 0.90 to 1.00 dl/g (ASTM D3236-88).

(8) Component b: B1-B13:

(9) The polyester-ethers were prepared using the following general procedure:

(10) In a 500 ml multinecked flask equipped with a KPG-stirrer, a vigreux column, a vacuum supply and a distillation bridge, the chemicals according to Table 1 are placed into the reactor under a nitrogen atmosphere and in an amount as given in Table 1. The mixture is heated to an internal temperature of 60° C., followed by the addition of 200 μl tetraisopropyl orthotitanate.

(11) Within 2 hours, the temperature of the reaction mixture is continuously increased to 230° C. under a weak nitrogen flow (5 l/h) and held at this temperature for 2 hours. After reaching 70° C., methanol starts to distill of. After reaching 190° C., ethylene glycol continuously starts to distill of. Thereafter, the N.sub.2-flow is stopped and the pressure of the reaction mixture is continuously decreased to 400 mbar at 230° C. within 165 minutes, followed by a further continuous pressure decrease to 1 mbar within 90 minutes. In the next step, the reaction mixture is stirred at a pressure of 1 mbar and an inner temperature of 230° C. for additional 4 hours. After the end of this time period, the inner pressure of the reaction flask is set back to 1 bar using N.sub.2 and the polymer melt is subsequently removed from the reactor and allowed to solidify.

(12) To determine the molecular weight of the Polyester-ether, GPC measurements were done under the following conditions: Columns: 1×PSS SDV Guard, 5 μm, 50 mm×8.0 mm ID 1×PSS SDV 100 Å, 5 μm, 300 mm×8.0 mm ID 1×PSS SDV 1000 Å, 5 μm, 300 mm×8.0 mm ID 1×PSS SDV 100000 Å, 5 μm, 300 mm×8.0 mm ID Detector: RI Oven temperature: 40° C. Flow: 1 ml/min Injection volume: 50 μl Eluent: THF Evaluation: PSS-WinGPC Version 8.2 Calibration: Polystyrene standards in the range from 682-1,670,000 Dalton Internal Standard: Toluene Injection concentration: 4 g/l in THF

(13) TABLE-US-00001 TABLE 1 Sample DMT/g DMI/g Poly-THF 1000/g Poly-THF 2000/g PEG 1000/g PR-1000/g MPEG 750/g M41/g B1 48.5 50.0 25.0 25.0 B2 48.5 50.0 37.5 12.5 B3 48.5 50.0 43.8 6.3 B4* 48.5 50.0 50.0 B5 43.7 4.9 50.0 37.5 12.5 B6 43.7 4.9 50.0 43.8 6.3 B7 43.7 4.9 50.0 46.9 3.1 B8 48.5 50.0 37.5 12.5 B9 48.5 50.0 37.5 12.5 B10 48.5 50.0 37.5 12.5 B11 48.5 50.0 12.5 B12 48.5 50.0 37.5 12.5 B13 48.5 50.0 18.8 Sample ε-Caprolactone/g 1,4 Butandiol/g EG/g PG/g Na-Acetate/g Θ Ω M.sub.w/g*mol.sup.−1 M.sub.n/g*mol.sup.−1 B1 125.0 0.3 0.8 1.5 17311 8073 B2 125.0 0.3 0.4 1.5 28398 12019 B3 125.0 0.3 0.2 1.5 35318 16430 B4* 125.0 0.3 0.0 1.5 39852 18412 B5 125.0 0.3 0.4 1.5 27623 11793 B6 125.0 0.3 0.2 1.5 36165 15054 B7 125.0 0.3 0.1 1.5 24979 10948 B8 125.0 0.3 0.4 1.5 27986 13604 B9 125.0 0.3 0.4 1.5 26281 11626 B10 125.0 0.3 0.4 1.5 38476 17954 B11 37.5 37.5 0.3 0.4 1.5 32345 11953 B12 29.3 24.7 0.3 0.4 1.5 29894 13465 B13 31.3 37.5 0.3 0.6 1.5 25310 10501 *B4 Comparative sample .fwdarw. no endcap was used for the synthesis of this polymer DMT = Dimethyl terephthalate DMI = Dimethyl isophthalate Poly-THF 1000 = Poly-THF-diol (average molecular weight (M.sub.n) = 1 KDa) Poly-THF 2000 = Poly-THF-diol (average molecular weight (M.sub.n) = 2 KDa) PEG 1000 = Poly(ethyleneglycol)-diol (average molecular weight (M.sub.n) = 1 KDa) PR 1000 = Poly(ethylenglycol)-co-poly(propylenglycol)-diol (average molecular weight (M.sub.n) = 1 KDa) MPEG 750 = Mono methoxylated poly(ethyleneglycol)-monool (average molecular weight (M.sub.n) = 0.75 KDa) M41 = Mono methoxylated poly(ethylenglycol)-co-poly(propylen-glycol)-monool (average molecular weight (M.sub.n) = 2000 KDa) EG = Ethylene glycol PG = Propylene glycol
Component c: C1:
Cobalt stearate solid form (9.5% Elemental cobalt concentration).
Component d: D1:
Surfactant
Masterbatches MB1 to MB10

(14) The components were homogenized together on a Leistritz® ZSE18HP extruder at the temperature of 260° C. to obtain solid masterbatches MB; Table 2 gives the details.

(15) TABLE-US-00002 TABLE 2 Components used [parts] Masterbatches A1 A2 B1 B4 B5 B8 B9 B10 B11 B12 B13 C1 D1 MB1 83 17 MB2 (Compound) 97.8 2.2 MB3 90 10 MB4 90 10 MB5 90 10 MB6 90 10 MB7 90 10 MB8 90 10 MB9 90 10 MB10 86 6 8
Preparation of Cast Films:

(16) As an example of operational mode, 200 m cast films were obtained via extrusion by using the Coiling E 25 PK by inserting the component A1, pre-dried for 18 hours at 120° C., into the main hopper of the machine, and by adding the other components (MB and/or pure additives directly dosed) through dosing units applied to the main stream of component A1 before entering the injection unit barrel. Extruder temperatures can be kept at 260° C. and flat die temperature is 270° C.

(17) The operating conditions during the test were: T1=60° C./T2=240° C./T3=260° C./T4=260° C./T5=260° C./T.sub.die=270° C./T.sub.calenderrollers=70° C./screw revolutions 80 rpm

(18) TABLE-US-00003 TABLE 3 ex-cpex Type of material Composition (%) cpex1 100 PET cpex2 MB 86.3 PET+ 12 MB1+ 1.7 MB10 ex2 CO 7.3 PET+ 91 MB2+ ex3 D 96.3 PET+ 2 B1+ ex4 D 2 B2+ ex5 D 2 B3+ cpex6 D 2 B4+ ex7 MB 78.3 PET+ 20 MB3+ ex8 MB 20 MB4+ ex9 MB 20 MB5+ ex10 MB 20 MB6+ ex11 MB 20 MB7+ ex12 MB 20 MB8+ ex13 MB 20 MB9 +

(19) The oxygen scavenging activity (in ml 02 consumed per gram of scavenging composition) corresponding to the cast films was measured by the methods described above. Table 4 reports the oxygen consumption of compositions with different copolymer structures and different amount of end caps.

(20) TABLE-US-00004 TABLE 4 ⊖ 0.0 0.2 0.4 0.8 0.4 0.6 Sample Day cpex6 ex5 ex4 ex3 ex11 ex13 0 0.0 0.0 0.0 0.0 0.0 0.0 2 6.2 6.2 4.7 2.0 3 0.8 0.6 6 24.0 20.8 17.9 6.4 7 29.1 24.8 21.8 7.8 4.5 3.1 9 37.5 32.1 27.4 9.2 10 13.0 6.5 12 44.7 42.2 36.0 11.8 14 52.0 50.6 42.2 14.8 28.2 13.2 17 39.4 19.7 19 68.3 64.4 55.6 23.0 21 71.9 70.5 60.1 27.2 50.7 26.4 23 76.8 70.5 64.5 31.4 26 82.2 76.5 68.1 36.9 28 91.8 78.8 71.6 40.9

(21) By comparison between ex3 to ex5 and cpex6 a significant dependence of the oxygen consumption rate with respect to the amount of end-caps present is observed. In general, the amount of consumed oxygen decreases when a higher amount of end-caps are introduced. The oxygen consumption rate is strongly dependent on the quantity of end-caps contained into the polyester-copolyether, so one can fine-tune and control the amount of oxygen being scavenged by increasing or reducing the amount of end-caps.

(22) This effect is observed when polyester-copolyether additives are dosed together with the resin directly into the hooper of the extruder as well as when a MB is prepared.

(23) Ex 1 and ex13 which refer to end-cap polyesters which are different from those in ex3 to ex5 and cpex6, show exactly the same behavior: higher amounts of end-caps reflect a reduction in oxygen consumption.