FLAME-RETARDANT THERMOPLASTIC POLYURETHANE

Abstract

The present invention relates to compositions comprising at least one thermoplastic polyurethane, a first phosphorus-containing flame retardant (F1) selected from the group consisting of melamine polyphosphates and a further phosphorus-containing flame retardant (F2) selected from the group consisting of derivatives of phosphinic acid, wherein the composition is free from melamine cyanurate, and to the use of such a composition for the production of cable sheathings.

Claims

1.-14. (canceled)

15. A composition, comprising: (i) a thermoplastic polyurethane, (ii) a melamine polyphosphate as a first phosphorus-containing flame retardant (F1) in an amount of from 5% to 20% by weight based on a total composition, (iii) a phosphinic acid derivative as a second phosphorus-containing flame retardant (F2) in an amount of from 10% to 35% by weight based on the total composition, and (iv) a third phosphorus-containing flame retardant in an amount of from 2% to 10% by weight based on the total composition, wherein the composition is free from melamine cyanurate.

16. The composition according to claim 15, wherein the composition is free from 3-, 4-, 5- and 6-hydric alcohols.

17. The composition according to claim 15, wherein the second phosphorus-containing flame retardant (F2) is a phosphinate.

18. The composition according to claim 17, wherein the phosphinate is selected from the group consisting of an aluminum phosphinate and a zinc phosphinate.

19. The composition according to claim 15, wherein the melamine polyphosphate has a phosphorus content of from 7% to 20% by weight.

20. The composition according to claim 15, wherein the melamine polyphosphate has a particle size of from 0.1 to 100 μm.

21. The composition according to claim 15, wherein the thermoplastic polyurethane is selected from the group consisting of a thermoplastic polyurethane based on at least one aromatic diisocyanate and at least one polycarbonate diol and a thermoplastic polyurethane based on at least one aromatic diisocyanate and polytetrahydrofuran polyol.

22. The composition according to claim 15, wherein the composition comprises a mixture comprising thermoplastic polyurethane TPU-1 based on an aliphatic diisocyanate and thermoplastic polyurethane TPU-2 based on an aromatic diisocyanate.

23. The composition according to claim 15, wherein a mixture of 1,4-butanediol and a further chain extender is employed as a chain extender to produce the thermoplastic polyurethane.

24. The composition according to claim 15, wherein the thermoplastic polyurethane is present in the composition in an amount of from 60% to 93% by weight based on the total composition.

25. The composition according to claim 15, wherein the composition comprises titanium dioxide in an amount of from 0.1% to 5% by weight based on the total composition.

26. A cable sheathing, comprising the composition according to claim 15.

Description

EXAMPLES

[0172] 1. Input Materials [0173] Elastollan A: TPU of Shore hardness 85 A from BASF Polyurethanes GmbH, Elastogranstrasse 60, 49448 Lemforde, based on polytetrahydrofuran polyol (PTHF) having a molecular weight of 1000 g/mol, 1,4-butanediol, 4,4′-diphenylmethane diisocyanate. [0174] Elastollan B: TPU of Shore hardness 90 A from BASF Polyurethanes GmbH, Elastogranstrasse 60, 49448 Lemforde, based on polycarbonate polyol from Ube (Eternacoll PH-200D, based on 1,5-pentanediol and 1,6-hexanediol) having a molecular weight of 2000 g/mol, 1,4-butanediol, 4,4′-diphenylmethane diisocyanate. [0175] Elastollan C: TPU of Shore hardness 60 D from BASF Polyurethanes GmbH, Elastogranstrasse 60, 49448 Lemforde, based on polytetrahydrofuran polyol (PTHF) having a molecular weight of 1000 g/mol, 1,4-butanediol, 4,4′-diisocyanatodicyclohexylmethane. [0176] TPU 1: TPU of Shore hardness 85 A from BASF Polyurethanes GmbH, Elastogranstrasse 60, 49448 Lemforde, based on polytetrahydrofuran polyol (PTHF) having a molecular weight of 1000 g/mol, 1,4-butanediol and propanediol in a molar ratio of 3:1, 4,4′-diphenylmethane diisocyanate. [0177] Melapur MC 15 ED: Melamine cyanurate (1,3,5-triazin-2,4,6(1H,3H,5H)-trione, compound with 1,3,5-triazine-2,4,6-triamine (1:1)), CAS #: 37640-57-6, BASF SE, 67056 Ludwigshafen, GERMANY, particle size D99%<1=50 μm, average particle diameter D50%<=4.5 μm, water content % (w/w)<0.2. [0178] Melapur MC 200/70: Melamine polyphosphate (nitrogen content 42-44% by wt., phosphorous content 12-14% by wt.)), CAS #: 218768-84-4, BASF SE, 67056 Ludwigshafen, [0179] GERMANY, particle size D99%</=70 μm, average particle diameter D50%<=10 μm, water content % (w/w)<0.3. [0180] Fyrolflex RDP: Resorcinol bis(diphenyl phosphate), CAS #: 125997-21-9, Supresta Netherlands B.V., Office Park De Hoef, Hoefseweg 1, 3821 AE Amersfoort, the Netherlands, viscosity at 25° C.=700 mPas, acid number <0.1 mg KOH/g, water content % (w/w)<0.1. [0181] Disflamoll DPK: Cresyl diphenyl phosphate, CAS #: 026444-49-5, LANXESS Deutschland GmbH, 51369 Leverkusen, Germany, acid number <0.1 mg KOH/g, water content % (w/w)<0.1. [0182] Exolit OP 1230: Aluminum diethylphosphinate, CAS #: 225789-38-8, Clariant Produkte (Deutschland) GmbH, Chemiepark Knapsack, 50351 Hürth, water content % (w/w)<0.2, particle size D99%<1=90 μm, average particle diameter D50=20-40 μm. [0183] Chisorb 622 LT: dimethyl butanedioate, polymer with 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinethanol, CAS #: 65447-77-0, BASF Polyurethanes GmbH, Postfach 1140, 49440 Lemfoerde, GERMANY. [0184] Tinuvin 234: 2-(2H-benzotriazol-2-yl)-4,6-bis(1-ethyl-1-phenylethylphenol) CAS #: 70321-86-17, BASF SE, 67056 Ludwigshafen, GERMANY. [0185] Hombitan LW-S: Anatase microcrystals without surface treatment, CAS #: 1317-70-0, Sachtleben Chemie GmbH, Duisburg, GERMANY, TiO2 proportion 99.2%; average particle size 0.3 μm.

[0186] 2. Production of the Mixtures

[0187] Tables 1a, 1b and 1c which follow list compositions in which the individual constituents are reported in parts by weight (pbw). The mixtures were in each case produced with a Berstorff ZE 40 A twin-screw extruder with a 35 D screw divided into 10 barrels.

[0188] All employed thermoplastic polyurethanes or mixtures of different polyurethanes have an average molecular weight of more than 150 000 Da.

TABLE-US-00001 TABLE 1a 1 2 3 5 6 (VB) (VB) (VB) 4 (VB) (VB) Composition Elastollan C 23 23 23 23 23 23 Elastollan A 47 47 47 47 47 47 Exolit OP 1230 30 20 Disflamoll DPK 30 20 Fyrolflex RDP 30 20 Melapur 15 ED MC 200/70 10 10 10

TABLE-US-00002 TABLE 1b 7 9 11 13 15 (VB) 8 (VB) 10 (VB) 12 (VB) 14 (VB) 16 Composition Elastollan C 23 23 23 23 23 23 21.5 21.5 19 19 Elastollan A 47 47 47 47 47 47 43.5 43.5 41 41 Exolit OP 1230 20 20 15 15 20 20 25 25 20 20 Melapur MC 15 ED 5 10 10 10 20 Melapur 200/70 5 10 10 10 20

TABLE-US-00003 TABLE 1c 17 18 19 20 21 22 23 Composition Elastollan C 15 15 23 31 15 Elastollan A 65.8 48.8 42.8 35.8 Elastollan B 48.8 TPU 1 65.8 50.8 Exolit OP 1230 20 20 20 20 20 20 20 Melapur 200/70 10 10 10 10 10 10 10 Tinuvin 234 0.6 0.6 0.6 0.6 0.6 0.6 0.6 Chisorb 622 0.6 0.6 0.6 0.6 0.6 0.6 0.6 Hombitan LW-S 3 3 3 3 3 3 3

TABLE-US-00004 TABLE 1d 24 25 Composition Elastollan A 70.8 70.8 Exolit OP 1230 10 15 Fyrolflex RDP 10 2 Melapur MC 200/70 5 8 Tinuvin 234 0.6 0.6 Chisorb 622 0.6 0.6 Hombitan LW-S 3 3

[0189] 3. Mechanical Properties

[0190] The mixtures were extruded with an Arenz single-screw extruder having a three-zone screw with a mixing section (screw ratio 1:3) to afford films having a thickness of 1.6 mm. Density, Shore hardness, tensile strength, tear propagation resistance, abrasion and elongation at break of the corresponding test specimens were measured. All compositions have good mechanical properties. The results are summarized in the following tables 2a, 2b and 2c.

TABLE-US-00005 TABLE 2a Composition 1 2 3 5 6 (VB) (VB) (VB) 4 (VB) (VB) Viscosity MFR 29 89 57 18 72 56 [g/10 min] 200° C., 5.00 kg Standard mechanics Density 1.18 1.16 1.18 1.20 1.19 1.22 [g/cm.sup.3] Shore [A] 85 57 66 88 70 71 TS [MPa] 26 34 45 26 29 35 EB [%] 420 580 550 430 550 540 TPR [kN/m] 51 29 32 60 38 44 Abrasion 137 74 89 157 108 115 [mm.sup.3]

TABLE-US-00006 TABLE 2b Composition 7 9 11 13 15 (VB) 8 (VB) 10 (VB) 12 (VB) 14 (VB) 16 Viscosity MFR 26 29 23 27 23 18 26 13 21 16 [g/10 min] (200° C./ 5 kg) Standard mechanics Density 1.21 1.18 1.21 1.18 1.21 1.19 1.22 1.22 1.26 1.27 [g/cm.sup.3] Shore [A] 88 89 87 87 85 88 91 90 92 92 TS [MPa] 28 29 27 28 24 26 18 22 16 15 EB [%] 470 480 450 470 410 430 380 410 360 380 TPR [kN/m] 59 62 64 61 56 60 55 63 58 59 Abrasion 120 123 137 138 135 157 174 169 160 201 [mm.sup.3]

TABLE-US-00007 TABLE 2c Composition 17 18 19 20 21 22 23 Viscosity MFR 19 25 20 32 64 23 29 [g/10 min] (200° C./ 5 kg) Standard mechanics Density 1.20 1.21 1.23 1.22 1.22 1.20 1.21 [g/cm.sup.3] Shore A [A] 87 88 90 90 91 86 87 TS [MPa] 21 21 22 20 19 21 21 EB [%] 470 540 500 560 540 470 480 TPR [kN/m] 56 56 60 57 58 53 53 Abrasion 183 164 170 178 186 156 152 [mm.sup.3]

TABLE-US-00008 TABLE 2d Composition 24 25 Viscosity MFR [g/10 min); 200° C., 21.6 20 kg MFR [g/10 min); 190° C., 21.6 35 kg Standard mechanics Density [g/cm.sup.3] 1.16 1.18 Shore [A] 76 88 Tensile strength [MPa] 34 36 Elongation at break [%] 710 510 Tear propagation resistance 40 55 [kN/m] Abrasion [mm.sup.3] 70 65

TABLE-US-00009 TABLE 3 Composition Test 17 18 19 20 21 22 23 Stickiness determination Wound cables no no no a a no no stick little lot Resilience Cables assume a a a a a no no shape of cable lot little little little little drum

[0191] 4. Flame Retardancy

[0192] To assess flame retardancy a conventional extrusion line (smooth tube extruder, extruder diameter 45 mm) for cable insulation and cable sheathing was used to produce cables. A conventional three-zone screw with a compression ratio of 2.5:1 was employed.

[0193] Initially the cores (4 twisted individual wires) were insulated with 0.1 mm of the respective mixtures by the hose method. The diameter of the insulated cores was 0.7 mm. Three of these cores were stranded and a sheath (sheath thickness 0.3 mm) was applied by extrusion by the hose method. The external diameter of the overall cable was 2 mm.

[0194] A VW 1 test (IA Standard 1581, § 1080-VW-1 (vertical specimen) flame test) was then performed on the cables. The test was performed on 3 cables in each case. The results are summarized in table 4.

TABLE-US-00010 TABLE 4 Fire test Composition (VW 1 test) 1 (VB) 0/3 2 (VB) 0/3 3 (VB) 0/3  4 3/3 5 (VB) 0/3 6 (VB) 0/3 7 (VB) 0/3  8 2/3 9 (VB) 0/3 10 2/3 11 (VB)  1/3 12 3/3 13 (VB)  1/3 14 3/3 15 (VB)  1/3 16 3/3 17 3/3 18 3/3 19 3/3 20 3/3 21 3/3 22 3/3 23 3/3

TABLE-US-00011 TABLE 4b Fire test Composition (VW 1 Test) 24 3/3 25 3/3

[0195] The results show that the inventive materials show improved flame retardancy properties. While positive fire test (VW 1 test) results were likewise obtained in individual tests for comparative experiments 13 and 15 this required a greater amount of flame retardant in the composition.

[0196] The advantage of the further addition of Fyroflex RDP (or another P-containing plasticizer liquid at RT) to the composition according to the invention is firstly the plasticizing effect without loss of flame retardancy properties (compare composition 17 to 24). The addition of RDP moreover considerably simplifies cable extrusion; much less nozzle abrasion material is formed.

[0197] 5. Discoloration Upon UV Irradiation

[0198] The mixtures were extruded with an Arenz single-screw extruder having a three-zone screw with a mixing section (screw ratio 1:3) to afford films having a thickness of 1.6 mm. The delta E values (ASTM E313) of the corresponding test specimens were measured after different irradiation times according to the method ASTM G155 Cy4. The results are summarized in table 5 which follows.

[0199] A small value for delta E represents a relatively low level of discoloration caused by the test. The lower the level of discoloration in the test the lower the level of discoloration that is to be expected in practical use, for example under the influence of sunlight.

[0200] The results show that the inventive materials show improved properties, in particular good long-term stability.

TABLE-US-00012 TABLE 5 Composition Test 17 18 19 20 21 22 23 Irradiation Color  0 h 0/0 0/0 0/0 0/0 0/0 0/0 0/0 difference 100 h 2.6/2.4 1.7/1.6 1.6/1.5 1.5/1.4 1.1/1.0 2.5/2.4 1.7/1.5 delta E 200 h 4.1/3.9 2.9/2.9 2.8/2.8 2.2/2.1 1.7/1.7 4.2/4.0 2.8/2.9 300 h 5.0/4.9 3.5/3.4 3.4/3.3 3.0/2.9 2.1/2.0 5.2/5.1 3.4/3.4

[0201] The inventive combination of a phosphinate with MPP (inventive examples 4, 8, 10, 12, 14, 16 and 17-23) gives better flame retardancy results than the combination of the phosphinate with MC.

[0202] Example 18, 19 and 23 are advantageous since good UV resistance is achieved along-side very low stickiness. Example 23 is particularly advantageous since good mechanical properties (tensile strength) are combined with good flame retardancy, good UV resistance and low resilience.

[0203] 6. Methods of Measurement:

[0204] Density: DIN EN ISO 1183-1, A.

[0205] Shore A hardness: DIN ISO 7619-1, Shore hardness test A (3s)

[0206] Tensile strength: DIN EN ISO 527

[0207] Elongation at break: DIN EN ISO 527

[0208] Tear propagation resistance: DIN ISO 34-1, B (b)

[0209] Abrasion: DIN 53516

[0210] Fire test: VW 1 test

[0211] Color difference delta E: ASTMG 155 Cy 4-without/with gloss

CITED LITERATURE

[0212] EP 0 617 079 A2 [0213] WO 2006/121549 A1 [0214] WO 03/066723 A2 [0215] US 2013/0059955 A1 [0216] US 2013/0081853 A1 [0217] WO 97/00916 A [0218] EP 0 019 768 A1 [0219] WO 03/066723 A1 [0220] WO 2006/121549 A1 [0221] PCT/EP2015/053192 [0222] EP 0 922 552 A1 [0223] DE 101 03 424 A1 [0224] WO 2006/072461 A1 [0225] Kunststoffhandbuch, volume VII, edited by Vieweg and Höchtlen, Carl Hanser Verlag, Munich 1966 (p. 103-113)