Water-Vapour Permeable Composite Parts

Abstract

The invention relates to water-vapour permeable, flat composite parts consisting of at least two layers, at least one layer being made of a polyester and polyether-based thermoplastic polyurethane. The invention also related to the use thereof.

Claims

1. A water vapour-permeable flat composite component comprising: (i) at least one layer not consisting of thermoplastic polyurethane; and (ii) at least one layer composed of polyether polyol-based thermoplastic polyurethane and polyester polyol-based thermoplastic polyurethane, wherein the layer (ii) consists of a thermoplastic polyurethane reaction product of the components consisting of: A) at least one organic diisocyanate; B) at least one component having two hydroxyl groups and in each case having a number-average molecular weight of 60 to 490 g/mol as chain extender; C) a component consisting of one or more polyether polyols each having a number-average molecular weight of 500-5000 g/mol, of which at least one polyether polyol (C1) contains ethylene oxide units; and D) 10% to 85% by weight, based on the total weight of C) and D), of one or more aliphatic polyester polyols each having a number-average molecular weight of 500-5000 g/mol; wherein the molar ratio of the NCO groups in A) to isocyanate-reactive groups in B), C), and D) is 0.9:1 to 1.2:1; wherein the total content of ethylene oxide units in component C) is at least 5% and not more than 45% by weight, based on the total weight of components C) and D), and the number-average functionality of the sum total of all the polyols in C) and D) is 1.8 to 2.5, and wherein the content of ethylene oxide units (X in % by weight) in component C), relative to the molar ratio Y of chain extenders B) to the sum total of components C) and D), is below the value of X which arises from the formula X (% by weight)=7.35*Y+13.75.

2. The flat composite component according to claim 1, wherein the diisocyanate A) is selected from the group consisting of: diphenylmethane 4,4-diisocyanate, isophorone diisocyanate, hexamethylene 1,6-diisocyanate, naphthylene 1,5-diisocyanate, dicyclohexylmethane 4,4-diisocyanate, and mixtures of any thereof.

3. The flat composite component according to claim 1, wherein the chain extender B) is at least one aliphatic chain extender having two hydroxyl groups.

4. The flat composite component according to claim 1, wherein the chain extender B) is at least one aliphatic chain extender having two hydroxyl groups and two to eight carbon atoms.

5. The flat composite component according to claim 1, wherein the chain extender B) is at least one compound selected from the group consisting of ethanediol, propanediol, butanediol, hexanediol, 1,4-di(beta-hydroxyethyl)hydroquinone, 1,4-di(beta-hydroxyethyl)bisphenol A, and mixtures of any thereof.

6. The flat composite component according to claim 1, wherein the chain extender B) contains at least two aliphatic chain extenders each having two hydroxyl groups.

7. The flat composite component according to claim 6, wherein the at least two aliphatic chain extenders each have two hydroxyl groups and two to eight carbon atoms.

8. The flat composite component according to claim 1, wherein at least one of the polyether polyols C1) containing ethylene oxide units in component C) is one component or a plurality of components selected from the group consisting of: poly(ethylene glycol), a copolymer of ethylene oxide units and 1,2-propylene oxide units, a copolymer of ethylene oxide units and 1,3-propylene oxide units, a copolymer of ethylene oxide units and 1,3-propylene oxide units and 1,2-propylene oxide units.

9. The flat composite component according to claim 1, wherein component C) is a component mixture selected from the group consisting of: poly(ethylene glycol) and poly(1,2-propylene glycol), of poly(ethylene glycol) and poly(1,3-propylene glycol), of poly(ethylene glycol) and poly(1,3-propylene glycol) and poly(1,2-propylene glycol), poly(ethylene glycol) and a polyol formed from ethylene oxide units and from propylene oxide units, of poly(1,2-propylene glycol) and a polyol formed from ethylene oxide units and from propylene oxide units, of poly(1,3-propylene glycol) and a polyol formed from ethylene oxide units and from propylene oxide units, of poly(ethylene glycol) and poly(1,2-propylene glycol) and a polyol formed from ethylene oxide units and from propylene oxide units, of poly(ethylene glycol) and poly(1,3-propylene glycol) and a polyol formed from ethylene oxide units and from propylene oxide units, of poly(ethylene glycol) and poly(1,3-propylene glycol) and poly(1,2-propylene glycol) and a polyol formed from ethylene oxide units and from propylene oxide units.

10. The flat composite component according to claim 1, wherein the polyether polyols in component C) together have a content of ethylene oxide units of 21% to 33% by weight, based on the total weight of C) and D).

11. The flat composite component according to claim 1, wherein at least one of the polyether polyols C1) containing ethylene oxide units in component C) additionally contains propylene oxide units and has 1% to 75% primary hydroxyl end groups.

12. The flat composite component according to claim 1, wherein at least one of the polyether polyols C1) containing ethylene oxide units in component C) is formed from 30% to 99% by weight of ethylene oxide units and 1% to 70% by weight of propylene oxide units.

13. The flat composite component according to claim 1, wherein component C) does not contain any poly(tetramethylene glycol).

14. The flat composite component according to claim 1, wherein the polyester polyols in D) are present in an amount of 10% to 55% by weight, based on the total weight of C) and D).

15. A roofing underlayment and exterior underlayment comprising the flat composite component according to claim 1.

16. The flat composite component according to claim 1, wherein the reaction is conducted in the presence of: E) catalysts.

17. The flat composite component according to claim 1, wherein the reaction is conducted in the presence of: F) assistants and/or additives.

18. The flat composite component according to claim 1, wherein the water vapour-permeable flat composite component comprises: (iii) further layers composed of thermoplastic polyurethane that do not directly adjoin the layer (ii) with a flat join.

Description

EXAMPLES

TPU Preparation

[0041] A reaction vessel was initially charged with the respective polyol with a temperature of 200 C., in which there had been dissolved, based on the total weight of all the feedstocks, 0.1% to 0.36% by weight of Carbodiimide ILF (Bayer MaterialScience AG, Leverkusen, DE), 0.1% to 0.88% by weight of Irganox 1010 (manufacturer: BASF SE, Ludwigshafen, DE), optionally 0.03% to 0.09% by weight of Irgafos PEPQ (BASF SE, Ludwigshafen, DE), 0% to 0.01% by weight of KL3-2049 (thermal stabilizer; Bayer MaterialScience AG, Leverkusen, DE) and 0.8% to 0.83% by weight of Licolub FA6 (manufacturer: Clariant, Gersthofen, DE) or Loxamid 3324 (Cognis Oleochemicals GmbH, Dusseldorf, DE). Then butane-1,4-diol (BDO) and hexane-1,6-diol (HDO), a sufficient amount of diphenylmethane 4,4-diisocyanate (MDI) at 60 C. that the index was 0.995 and 10 to 14 ppm of titanium acetylacetonate as catalyst were added while stirring, and the complete reaction mixture was stirred vigorously for 10 to 25 seconds. Subsequently, the viscous reaction mixture was poured onto a coated metal sheet and heat-treated at 80 C. for a further 30 minutes. The cast sheets obtained were cut and pelletized.

[0042] Raw materials used: [0043] Polyol A Polyether L5050 (OH number: 55.9-57.2 mg KOH/g, 1,2-propylene glycol-started bifunctional polyether formed from ethylene oxide and propylene oxide with an ethylene oxide cap (about 10% by weight), an ethylene oxide content of about 50% by weight and with 60%-70% primary hydroxyl end groups); Bayer MaterialScience AG, Leverkusen, DE [0044] Polyol B Acclaim Polyol 2200 N (OH number: 56.1 mg KOH/g, poly(1,2-propylene glycol)); Bayer MaterialScience AG, Leverkusen, DE [0045] Polyol C Polyether PW56 (OH number: 56.7 mg KOH/g, poly(ethylene glycol)); Bayer MaterialScience AG, Leverkusen, DE [0046] Polyol D Polyester PE 225B (OH number: 50-50.9 mg KOH/g, poly(1,4-butanediol adipate)); Bayer MaterialScience AG, Leverkusen, DE [0047] Polyol E Polyester PE 90B (OH number: 117.7-120.7 mg KOH/g, poly(1,4-butanediol adipate)); Bayer MaterialScience AG, Leverkusen, DE [0048] Polyol F Desmophen 2002H (OH number: 54.7-57.6 mg KOH/g, poly(ethanediol adipate-co-butane-1,4-diol adipate)); Bayer MaterialScience AG, Leverkusen, DE [0049] MDI Desmodur 44 M (diphenylmethane 4,4-diisocyanate); Bayer MaterialScience AG, Leverkusen, DE [0050] BDO butane-1,4-diol; BASF SE, Ludwigshafen, DE [0051] HDO hexane-1,6-diol; Lanxess, Uerdingen, DE

TABLE-US-00001 TABLE 1 Preparation of TPUs Polyether Polyester Polyether polyol Polyester polyol BDO HDO MDI TPU polyol [pts. by wt.] polyol [pts. by wt.] [pts. by wt.] [pts. by wt.] [pts. by wt.] 1* B 30.5 D/E 24.4/6.1 7.2 0.8 29.7 2 A 27.3 D/E 28.5/6.1 6.9 0.8 29.1 3 A 33.5 D/E 23.5/5.1 6.9 0.8 29.1 4* C 31 D/E 24.8/6.2 6.9 0.8 29.1 5 A 20.7 D/E 32.9/7.4 7.2 0.8 29.7 6 A 26.9 D/E 27.9/6.2 7.2 0.8 29.7 7* A 38.6 D/E 21.5/4.2 6.1 0.8 27 8 A 36 D/E 20.1/3.9 7.4 0.8 30 9* A 45.3 F 19.4 6.1 0.8 26.7 10 A 41.8 F 17.9 7.5 0.7 29.9 11 A 32.1 D/E 26.8/5.3 6.1 0.8 27 12* A 41.7 D/E 14.8/3.sup. 7.5 0.8 30.2 13* A 47.8 D/E 9.9/2 7.6 0.8 30.2 14* A 42 D/E 15.2/3.sup. 7.4 0.8 30 15 A 41.8 F 17.9 7.5 0.7 29.9 16* A 48 F 12 7.6 0.8 30 17* C 14.2 D/E 37.8/7.2 7.5 0.8 30.4 18* C 16.6 D/E 35.9/6.9 7.5 0.8 30.4 19 A 33 D/E .sup.23/5.1 7.2 0.8 29.6 20 A 31.2 D/E 26.1/5.1 6.6 0.8 28.3 21 A 29.3 D/E 29.9/5.9 5.8 0.9 26.4 22 A 34.9 D/E 23.9/4.7 6.3 0.8 27.6 23 A 34.9 D/E 23.9/4.7 6.3 0.8 27.6 24* A 48.8 D/E 10.1/2.1 7.2 0.8 29.4 25* A 45.7 D/E 16.1/3.5 5.8 0.8 26.3 26 A 40.1 D/E 16.4/3.4 7.6 0.8 30.3 27* A 49 F 12.2 7.2 0.8 29.2 *comparative examples

TABLE-US-00002 TABLE 2 Additive and catalyst contents of the TPUs prepared Titanium Carbodiimide Irganox Irgafos Licolub Loxamid acetyl- ILF 1010 PEPQ KL3-2049 FA6 3324 acetonate TPU [% by wt.] [% by wt.] [% by wt.] [% by wt.] [% by wt.] [% by wt.] [ppm] 1* 0.2 0.1 0.8 14 2 0.24 0.12 0.8 14 3 0.2 0.1 0.8 14 4* 0.2 0.1 0.8 14 5 0.28 0.14 0.8 14 6 0.24 0.12 0.8 14 7* 0.21 0.64 0.06 0.01 0.83 10 8 0.19 0.6 0.06 0.01 0.83 10 9* 0.16 0.65 0.07 0.01 0.83 14 10 0.14 0.88 0.09 0.01 0.83 14 11 0.26 0.64 0.06 0.01 0.83 10 12* 0.14 0.88 0.09 0.01 0.83 14 13* 0.1 0.6 0.06 0.01 0.83 14 14* 0.15 0.6 0.06 0.01 0.83 10 15 0.14 0.88 0.09 0.01 0.83 14 16* 0.1 0.59 0.06 0.01 0.83 14 17* 0.36 0.7 0.07 0.01 0.83 14 18* 0.34 0.66 0.07 0.004 0.83 14 19 0.2 0.1 0.8 14 20 0.25 0.63 0.06 0.01 0.83 10 21 0.29 0.65 0.06 0.01 0.83 10 22 0.23 0.64 0.07 0.01 0.83 10 23 0.23 0.64 0.07 0.01 0.83 10 24* 0.1 0.6 0.06 0.01 0.83 14 25* 0.16 0.65 0.06 0.01 0.83 14 26 0.16 0.3 0.03 0.002 0.83 14 27* 0.1 0.6 0.06 0.01 0.83 14 *comparative examples

TPU Film Production

[0052] The pelletized TPU materials 1 to 27 were each melted in a single-shaft extruder (Brabender Plasticorder PL 2100-6 30/25D single-shaft extruder) (metering rate about 3 kg/h; 185-225 C.) and extruded through a slot die to give a flat film in each case.

Measurement of Water Vapour Permeability (WVP) of the Composite Component by Measuring the WVP of the TPU Films Used

[0053] The water vapour permeability (WVP) of the films produced was determined in a method based on DIN 53122. For this purpose, the films were stretched and fixed over a 50 ml or 100 ml vessel (diameter 46.5 mm). The vessel had been charged beforehand with 40 g of silica gel granules (diameter 1-3 mm, with indicator) which had been baked at 130 C. for 12 h. For the measurement, the vessel was conditioned in a desiccator over saturated aqueous potassium chloride solution (air humidity about 85%) and at room temperature. Every 2 h, the weight was determined until the weight increase was constant (6-8 h). In the comparison of WVP values, it should be noted that, because of temperature differences between measurements on different days, it is possible to compare only results for samples which have been tested together in the same desiccator at the same time.

Determination of the Swelling of the TPU Films

[0054] To determine the intensity of the swelling, water droplets were applied to the flat films and, after a contact time of 10 min, removed again cautiously with an absorptive cloth. The points where the water droplets had been present were then examined as to whether the flat film had lifted off the substrate (significant swelling) or not (slight swelling, if any).

Production of Injection-Moulded TPU Sheets for Measurement of the Mechanical Properties of the TPUs Used

[0055] The TPU pellets were melted in an Arburg Allrounder 470 S 1000-290 injection moulding machine (30 mm screw) and shaped to S1 specimens (melt temperature about 220 C., mould temperature: 25 C., specimen size: 11525/62 mm).

Measurement of Mechanical Properties

[0056] The ultimate tensile strength and elongation at break were determined by measurements in a tensile test to DIN 53504 on S1 specimens.

[0057] The most important properties of the TPU films or S1 specimens thus produced are reported in Tables 3 and 4.

TABLE-US-00003 TABLE 3 Water vapour permeability (WVP) and swelling of the TPU films Moles of all CEs: moles Polyether Ethylene oxide groups Film of all polyol in components C) and thickness WVP TPU polyols [pts. by wt.] D) [% by wt.] Swelling [m] [g/m.sup.2/d] 1* 2.64 30.5 0 none 50 147 2 2.53 27.3 22 none 60 194 3 2.68 33.5 27 very low 60 222 4* 2.5 31 50 significant 60 274 5 2.63 34 17 none 50 179 6 2.65 44 22 none 50 250 7* 2.21 60 30 significant 50 464 8 2.85 60 30 none 45 326 9* 2.3 70 35 significant 30 259 10 2.99 70 35 low 70 147 11 2.19 50 25 none 45 420 12* 2.89 70 35 moderate to 35 269 significant 13* 2.91 80 40 significant 35 299 14* 2.85 70 35 significant 55 412 15 2.99 70 35 low 35 252 16* 2.98 80 40 significant 33 292 17* 2.79 24 24 moderate 35 163 18* 2.8 28 28 significant 35 187 *comparative examples; CEs = chain extenders

[0058] The inventive examples show good water vapour permeability with simultaneously low swelling (see Table 3).

TABLE-US-00004 TABLE 4 Swelling, ultimate tensile strength and elongation at break Ultimate tensile strength TPU Swelling MPa Elongation at break % 7* significant 27.4 945 8 none 31.8 795 9* significant 27.7 1045 11 none 45.3 755 12* moderate to 19.9 939 significant 13* significant 28.4 876 14* significant 30.1 880 15 low 31.1 837 16* significant 28.9 879 20 none 28.9 854 21 none 21.5 960 22 very low 36.6 835 24* significant 29.5 874 25* significant 25.5 1069 26 low 30.8 837 27* very significant 25.3 967 *comparative examples

[0059] The swelling of the inventive TPUs is low, with simultaneously adequate ultimate tensile strength and elongation at break (see Table 4).

[0060] The TU films used in accordance with the invention, based on comparatively inexpensive polyether polyols having adequate reactivity, exhibit good water vapour permeabilities and adequate mechanical properties with simultaneously low swelling, such that it is thus possible to provide flat composite components having the corresponding properties.