Polymer composition that can be extruded into a vapour-permeable object

Abstract

The present invention relates to an extrudable polymer composition comprising: 99.5 to 99.95% of at least one hard-soft block copolymer comprising: at least 25% by weight of soft block polyethylene glycol (PEG) with functionality equal to 2, with respect to the total weight in copolymer; from 0.05 to 0.5% by weight of at least one polyol comprising at least three hydroxyl groups, with respect to the total weight of the composition; characterised in that: the weight-average molecular mass of said copolymer is at least equal to 100,000 g/mol; and the weight-average molecular mass of the polyol is at least equal to 1000 g/mol; and said at least one polyol binding hard copolymer blocks by ester bonds. This invention relates in particular to the use of said composition in extrusion processes for manufacturing vapour-permeable objects.

Claims

1. An extrudable polymer composition comprising: from 50 to 99.95% by weight of at least one hard-soft block copolymer comprising: at least one hard block and at least one soft block, wherein the at least one hard block is polyamide-based, polyurethane-based, polyester-based or a combination thereof; at least 25% by weight of polyethylene glycol (PEG) with functionality equal to 2, with respect to the total weight of the hard-soft block copolymer; and from 0.01 to 5% by weight of at least one polyol with functionality greater than 2 and comprising at least three hydroxyl groups, with respect to the total weight of the composition, wherein: the weight-average molecular mass of said hard-soft block copolymer is at least equal to 100,000 g/mol; and the weight-average molecular mass of the polyol is at most equal to 1000 g/mol; and said at least one polyol is bound to the at least one hard block by ester bonds.

2. The extrudable composition according to claim 1, wherein it comprises from 0.15 to 0.2% by weight of said polyol, with respect to the total weight of the composition.

3. The composition according to claim 1, wherein said at least one hard-soft block copolymer comprises at least one block chosen among: polyether blocks other than PEG; polyester blocks; polyamide blocks; polyurethane blocks; or combinations thereof.

4. The composition according to claim 1, wherein the at least one hard-soft block copolymer is comprised of hard blocks and soft blocks, wherein the ratio by weight of hard blocks to soft blocks is in the range from 0.5 to 3.

5. The composition according to claim 1, wherein: the at least one hard block represents from 30 to 55% by weight; and the at least one soft block represents from 45 to 70% by weight, of the total weight of the hard-soft block copolymer.

6. The composition according to claim 1, wherein the number-average molecular mass Mn of the at least one soft block of the hard-soft block copolymer is in the range from 500 to 3000 g/mol.

7. The composition according to claim 1, wherein the number-average molecular mass Mn of the at least one hard block of the hard-soft block copolymer is in the range from 500 to 3000 g/mol.

8. The composition according to claim 1, wherein said at least one hard-soft block copolymer comprises a copolymer with hard polyamide blocks and soft polyether blocks (PEBA).

9. The composition according to claim 1, wherein said at least one hard-soft block copolymer comprises from 45 to 75% by weight of polyethylene glycol (PEG) blocks, for the total weight of the hard-soft block copolymer.

10. The composition according to claim 1, wherein said at least one hard-soft block copolymer comprises at least 50% by weight of PA blocks chosen among: PA6, PA6.6, PA10.10, PA10.12, PA11, PA12, PA6/12, PA6/6.6, and combinations thereof.

11. The composition according to claim 1, wherein said at least one hard-soft block copolymer is chosen among the following PEBAs: PA6-PEG, PA10.10-PEG, PA10.12-PEG, PA11-PEG, PA12-PEG, PA6/12-PEG, PA6.6-PEG, PA6/6.6-PEG, and combinations thereof.

12. The composition according to claim 1, wherein the weight-average molecular mass of the at least one hard-soft block copolymer is in the range from 100,000 to 200,000 g/mol.

13. The composition according to claim 1, wherein the weight-average molecular mass of said at least one polyol is in the range from 50 to 1000 g/mol.

14. The composition according to claim 1, wherein said at least one polyol is chosen among: pentaerythritol, trimethylolpropane, trimethylolethane, hexanetriol, diglycerol, methylglucoside, sorbitol, dipentaerythritol, cyclodextrin, polyether polyols comprising at least three hydroxyl groups, and combinations thereof.

15. The composition according to claim 1, wherein its melt viscosity at 230° C. (Pa.Math.s) is greater than 400 Pa.Math.s, measured in accordance with ISO standard 1621-10: 2015.

16. The composition according to claim 1, wherein it does not comprise any polyolefin.

17. The composition according to claim 1, wherein it also comprises at least one polyamide chosen among: PA12, PA11, PA10.10, PA6, PA 6.6, PA6/12, a copolyamide comprising at least one of the following monomers: 6, 11, 12, 5.4, 5.9, 5.10, 5.12, 5.13, 5.14, 5.16, 5.18, 5.36, 6.4, 6.6, 6.9, 6.10, 6.12, 6.13, 6.14, 6.16, 6.18, 6.36, 10.4, 10.9, 10.10, 10.12, 10.13, 10.14, 10.16, 10.18, 10.36, 10.T, 12.4, 12.9, 12.10, 12.12, 12.13, 12.14, 12.16, 12.18, 12.36, 12.T and combinations or copolymers thereof.

18. An extrusion process wherein it uses an extrudable polymer composition according to claim 1, to manufacture a film, sheet, membrane, plate, profile, tube, pipe, hollow body, reservoir, synthetic casing, cable, rod, filament or fibre.

19. An extruded object manufactured in accordance with claim 18, said object having a vapour permeability (MVTR) of at least 700 g/m2 per 24 hours at 23° C., at 50% relative humidity and a sample thickness of 30 μm, measured in accordance with ASTM standard E96B.

20. The extruded object according to claim 19, wherein it has a saturated water content at 23° C. in the range of from 50 to 500% by weight, in accordance with ISO standard 62: 2008, in relation to the weight in PEBA.

21. The object according to claim 19, wherein it has a tensile elastic modulus below 500 MPa, measured in accordance with ISO standard 527-2: 2012-1A.

22. The object according to claim 19, wherein it has an instantaneous hardness in the range of from 20 to 60 Shore D, in accordance with ISO standard 868: 2003.

23. The object according to claim 19, said object being a packaging component; a food wrap; a wrapping for cooking and/or smoking; a waterproof, breathable film; a component used in textiles, sports equipment, shoes, sports shoes, shoe soles, decoration, luggage, glasses, furniture, in electrical, electronic, audio-visual, computer, automotive or aeronautic equipment; and/or a component in medical equipment.

24. An extrusion method to manufacture a vapour-permeable object with the polymer composition according to claim 1, wherein the method comprises drawing the composition by blow moulding; and extruding the composition through a heated ring nozzle.

Description

EXAMPLES

(1) The following examples illustrate the present invention without limiting the scope thereof. In the examples, unless otherwise stated, all percentages and portions are expressed in weight.

(2) Copolymers used in the compositions in the following tests (examples and comparisons):

(3) Comparison 1: Cp1

(4) PEBA 1: PA12-PEG based on PA12 blocks of Mn=4500 g/mol and PEG blocks of Mn=1500 g/mol; hard block/soft block ratio: 3.

(5) Weight-average molecular mass of the PEBA 1 (Mw)=111,000 g/mol

(6) Comparison 2: Cp2

(7) PEBA 2: PA6-PEG based on PA6 blocks of Mn=1500 g/mol and PEG blocks of Mn=1500 g/mol; hard block/soft block ratio: 1.

(8) Weight-average molecular mass of the PEBA 2 (Mw)=112,000 g/mol

Example 1 According to the Invention: Ex1

(9) PEBA 2+0.1% pentaerythritol (“PET”) composition

(10) Weight-average molecular mass of the PEBA 2+0.1% PET (Mw)=144,000 g/mol

(11) Although the tests refer to a PEBA (Pebax®)-based composition, it is clearly understood that the compositions according to the present invention are not limited to this embodiment, but can comprise any type of block copolymer, alone or in combination.

(12) Table 1 below shows the results for inherent viscosity and melt viscosity for compositions Cp1, Cp2 and Ex1, as well as the results of the measurements of MVTR, saturated water content, and hardness obtained for objects extruded from these respective compositions.

(13) TABLE-US-00001 TABLE 1 Inherent viscosity Melt viscosity MVTR ASTM Saturated ISO 307 ATO: 0.5% at 230° C., 10 E96 B (per 24 water content Shore D Test/ mass in metacresol rad/s (Pa .Math. s) ISO hrs, at 23° C., at 23° C. (%) Hardness Composition at 20° C., in g/g 6721-10: 2015 RH 50%, 30 μm) ISO 62: 2008 ISO 868: 2003 Cp1/PEBA 1 1.5 700 560 <50 60 (12/PEG 4500/1500) Cp2/PEBA 2 1.35 200 1070 >100 40 (6/PEG 1500/1500) Ex1/PEBA 2 + 1.4 500 1125 >100 40 0.1% PET

(14) It can be seen that composition Ex1 according to the invention is more easily extrudable than composition Cp2.

Table 2

(15) Table 2 shows the results for the tensile strength measured in accordance with ISO standard 527-2: 2012-1A.

(16) Tensile tests were conducted on both 30 μm-thick films manufactured using CAST technology. The longitudinal and transversal directions were studied in both films with three test samples for each direction.

(17) v=100 L0=50;

(18) Vinitial=1 mm/min up to 1% deformation of the test sample (to calculate the modulus);

(19) Vfinal=100 mm/min up until the test sample broke (to measure the deformation and stress at yield and break.)

(20) The test samples used were ISO 527-3 strips and L0 was set at 50 mm.

(21) TABLE-US-00002 At yield At break Warping (%) Stress (MPa) Warping (%) Stress (MPa) direction Mean (n = 3) s Mean (n = 3) s Mean (n = 3) s Mean (n = 3) s Cp2 longitudinal 26 5 10.4 1.0 524 32 46.4 6.1 transversal 21 2 6.9 0.3 934 30 34.2 2.2 Ex1 longitudinal 26 4 10.3 0.3 537 54 46.7 4.4 transversal 19 1 6.7 0.1 849 16 28.7 1.0 Modulus (MPa) direction Mean (n = 3) s Cp2 longitudinal 48.9 4.3 transversal 75.4 3.2 Ex1 longitudinal 58.8 4.2 transversal 73.7 3.9

(22) The mechanical properties of the Cp2 and Ex1 films obtained are similar, whether in the longitudinal or transversal extrusion direction.