POLYURETHANE POLYMER HAVING A HARDNESS OF LESS THAN OR EQUAL TO 60 SHORE A AND GOOD ABRASION RESISTANCE

Abstract

The present invention relates to a novel thermoplastically processible polyurethane polymer having a hardness of ≤60 Shore A, to compositions containing this polyurethane polymer, to the uses thereof and to articles containing this polyurethane polymer.

Claims

1. A thermoplastically processible polyurethane polymer having a hardness of 60 Shore A, obtained by reacting the following components (A) one or more essentially linear polyether polyols and/or polyester polyols, where a total amount of component (A) has an average molecular weight Mn in a range from 500 g/mol to 5000 g/mol, Mn having been calculated from an OH number determined according to DIN53240, (B) one or more diisocyanates comprising 2-methyl-1,5-diisocyanatopentane, 1,4-diisocyanatobutane (BDI), 1,5-diisocyanatopentane, 1,6-diisocyanatohexane, 2,2,4-trimethyl-1,6-diisocyanatohexane, 2,4,4-trimethyl-1,6-diisocyanatohexane, or diphenylmethane diisocyanate isomer mixtures having a diphenylmethane 4,4′-diisocyanate content of >96% by weight, (C) one or more linear diols having a molecular weight of 62 g/mol to 500 g/mol, (D) optionally in the presence of one or more catalysts, (E) optionally in the presence of one or more additives, auxiliaries additions, or a combination thereof, and (F) optionally in the presence of one or more monofunctional chain terminators, wherein the reaction is performed in a solvent-free fashion and comprises: 1) providing and reacting a mixture made up of the total amount of component (A), a portion of component (B) and optionally a portion or a total amount of component (D), component (E), component (F), or a combination thereof to give an NCO-functional prepolymer, wherein there is a molar ratio of component (B) to component (A) in a range from 1.1:1.0 to 5.0:1.0, 2) reacting the NCO-functional with a total amount of component (C) to obtain an OH-functional prepolymer, optionally in the presence of a further portion of component (D), component (E), component (F), or a combination thereof 3) reacting the OH-functional prepolymer with a remaining amount of component (B) and any remaining amount of component (D), component (E), component (F), or a combination thereof to obtain a thermoplastically processible polyurethane, wherein during all process steps there is a molar ratio of component (B) to a sum total of component (A) and component (C) in a range from 0.9:1.0 to 1.2:1.0.

2. The thermoplastically processible polyurethane polymer according to claim 1, wherein components (A) comprises polyester diols having a melting temperature of ≤50° C., polyether polyols, or mixtures of at least 2 of these.

3. The thermoplastically processible polyurethane polymer according to claim 1, wherein component (B) comprises 2-methyl-1,5-diisocyanatopentane, 1,6-diisocyanatohexane 2,2,4-trimethyl-1,6-diisocyanatohexane, diphenylmethane diisocyanate isomer mixtures having a diphenylmethane 4,4′-diisocyanate content of >96% by weight, or mixtures of at least 2 of these.

4. The thermoplastically processible polyurethane polymer according to claim 1, wherein components (C) comprises ethane-1,2-diol, butane-1,4-diol, hexane-1,6-diol, 1,4-di(hydroxyethyl)hydroquinone, cyclobutane-1,3-diol, or mixtures of at least 2 of these.

5. The thermoplastically processible polyurethane polymer according to claim 1, wherein the thermoplastically processible polyurethane polymer has a hardness in a range from 35 Shore A to 60 Shore A as determined in accordance with DIN ISO 7619-1.

6. A plasticizer-free composition comprising at least one thermoplastically processible polyurethane polymer having a hardness of ≤60 Shore A according to claim 1 and an additive.

7. A roller or a wheel, comprising: a thermoplastically processible polyurethane polymer having a hardness of ≤60 Shore A according to claim 1.

8. The roller or the wheel according to claim 7, wherein the roller or the wheel is part of a transport container, a suitcase, a sports bag, a leisure bag, a pannier, furniture, a medical device, a hospital bed, a shopping trolley, a lift, or an escalator.

9. The roller or the wheel according to claim 7, wherein the rollers or the wheel is a drive rollers or a pressure rollers.

10. A roller or a wheel comprising the plasticizer-free composition according to claim 6.

11. The roller or the wheel according to claim 10, wherein the roller or the wheel is part of a transport container, a suitcase, a sports bag, a leisure bag, a pannier, furniture, a medical device, a hospital bed, a shopping trolley, a lift, or an escalator.

12. The roller or the wheel according to claim 10, wherein the roller or the wheel is a drive roller.

13. A shoe sole, comprising a thermoplastically processible polyurethane polymer having a hardness of ≤60 Shore A according to claim 1.

14. The shoe sole according to claim 13, wherein the shoe sole is a shoe outsole.

15. A shoe sole comprising a plasticizer-free composition according to claim 6.

16. The shoe sole according to claim 15, wherein the shoe sole is a shoe outsole.

17. An elastic bearing element or an elastic connecting element, comprising a thermoplastically processible polyurethane polymer having a hardness of ≤60 Shore A according to claim 1.

18. The elastic bearing element or an elastic connecting element according to claim 17, wherein the elastic bearing element or the elastic connecting element is a damper bearing, a spring seat, a door stop damper, or a bearing sleeve.

19. An elastic bearing element or an elastic connecting element comprising a plasticizer-free composition according to claim 6.

20. The elastic bearing element or the elastic connecting element according to claim 19, wherein the elastic bearing element or the elastic connecting element is a damper bearing, a spring seat, a door stop damper, or a bearing sleeve.

21. A component for automobile interiors, comprising a thermoplastically processible polyurethane polymer having a hardness of 60 Shore A according to claim 1.

22. The component for automobile interiors according to claim 21, wherein the component for automobile interiors is part of a roller blind, a sliding cover, a louvre shutter, a cupholder, a gearshift cover, a storage compartment, a door handle, a charging cradle, an anti-slip mat, an injection-moulded gaiter, a blow-moulded gaiter, a flexible seal, a rotary switch, a pushbutton switch, or a door stop.

23. A component for automobile interiors, comprising a plasticizer-free composition according to claim 6.

24. The component for automobile interiors according claim 23, wherein the component for automobile interiors is part of a roller blind, a sliding cover, a louvre shutter, a cupholder, a gearshift cover, a storage compartment, a door handle, a charging cradle, an anti-slip mat, an injection-moulded gaiter, a blow-moulded gaiter, a flexible seal, a rotary switch, a pushbutton switch, or a door stop.

Description

EXAMPLES

[0121] Table 1 illustrates the invention on the basis of a few examples. The preparation processes used are described hereinbelow.

[0122] Process 1*: Soft Segment Pre-Extension (in Accordance with EP-A 1338614), not According to the Invention

[0123] Step 1: Portion 1 of the MDI is brought to conversion of >90 mol %, based on the polyol, with 1 mol of polyol or polyol mixture with stirring at approx. 140° C.

[0124] Step 2: Portion 2 of the MDI and then the chain extender are added to the stirred reaction mixture, after vigorous mixing (approx. 20 s), the reaction mixture is cast onto a metal sheet and subsequently heat treated for 30 minutes at 120° C.

[0125] Process 2: MDI Multistage Pre-Extension Process According to the Invention

[0126] Step 1: Portion 1 of the MDI is brought to conversion of >90 mol %, based on the polyol, with 1 mol of polyol or polyol mixture with stirring at approx. 140° C.

[0127] Step 2: The chain extender is added to the stirred reaction mixture and this is stirred vigorously for approx. 10 s.

[0128] Step 3: Portion 2 of the MDI is added to the stirred reaction mixture. The reaction mixture is stirred for a further 20 s, subsequently cast onto a metal sheet and heat-treated for 30 minutes at 120° C.

[0129] The cast TPU slabs obtained were cut and pelletized. The pellets were processed using an Arburg Allrounder 470S injection-moulding machine in a temperature range from 180° to 230° C. and in a pressure range from 650 to 750 bar at an injection rate of from 10 to 35 cm.sup.3/s to give bars (mould temperature: 40° C.; bar size: 80×10×4 mm) or slabs (mould temperature: 40° C.; size: 125×50×2 mm).

[0130] From the TPU products produced, the mechanical values (100% modulus, 300% modulus, tear strength, elongation at break and Shore A/D hardness), the solidification rate, the abrasion resistance and the compression set were determined and the ageing resistance ascertained.

TABLE-US-00001 TABLE 1 Comparative examples 1 and 4, examples 2, 3, 5, 6 and 7: Measurement results of soft TPUs MDI/ MDI/ 100% Tensile Hardness at Experiment Chain portion 1 portion 2 Theoretical Hardness modulus strength 0s/60s number Process Polyol extender [mol] [mol] hardness.sup.# [Shore] [MPa] [MPa] [Shore A]  1* 1 1 MEG 1.5 0.539 12 42A 2.4 15.3 19/25 2 2 1 MEG 1.5 0.539 12 47A 1.5 15.1 26/33 3 2 1 MEG 1.5 1.642 22.4 60A 4.3 14.4 39/43  4* 1 1 MEG 1.3 0.739 12 40A 1.1 9.8 11/18 5 2 1 MEG 1.3 0.739 12 49A 1.9 11.8 30/34 6 2 1 MEG 2 0.373 16 55A 2.1 12 35/48 7 2 1 BDO 2 0.255 16 59A 1.6 14.9 20/45 *Comparative example not according to the invention, .sup.#The theoretical hardness is the proportion of the hard segments of the TPU: e.g. TH = n(BDO + MDI)/(n(BDO + MDI) + m(Polyol + MDI))

TABLE-US-00002 TABLE 2 Comparative example 1 and inventive examples 2, 3 and 6 Measurement results of the determination of abrasion resistance, of the determination of compression set and of the ageing test. Tensile Ageing test at 80° C. Ageing test at 110° C. strength tensile strength tensile strength Abrasion Compression set [MPa] [MPa] [MPA] Experiment resistance Method A Method C 0 28 28 number [mm.sup.3] 24 h/70° C. 24 h/70° C. 72 h/23° C. Days Days Days  1* 224 30 24 14 2 96 21.4 16.7 8.9 3 38 22 12 14.4 11.1 10.1 6 46 33 14 12 11.6 7.2 *Comparative example not according to the invention

[0131] In the examples listed in Table 1 (Experiments 1, 2, 4 and 5), which were produced from the same raw materials and with the same theoretical hardness by different processes, it can be clearly seen that the TPU materials which were produced by the multistage process according to the invention (Process 2) solidify much more quickly, that is to say the hardness measured after 0 seconds and also after 60 seconds after removal from the injection moulding machine is higher than in the respective comparative experiments. It is clearly apparent for Experiments 6 and 7 that the TPUs based on monoethylene glycol (MEG) solidify more rapidly than those based on butane-1,4-diol (BDO).

[0132] The examples listed in Table 2 correspond to the respective examples from Table 1. It is clearly apparent that the abrasion resistance of Examples 2, 3 and 6 according to the invention is significantly lower than in Comparative Example 1. The examples according to the invention also exhibit markedly better values for the determination of the compression set. It can be seen from Examples 3 and 6 according to the invention that the polyurethanes according to the invention have good ageing resistance.

[0133] Comparative Example with Addition of Solvent and Example According to the Invention without Addition of Solvent

[0134] For Comparative Example 8, the polyol used was Acclaim® Polyether 2200N (polyol 1) and the procedure was in accordance with the experiment description in U.S. Pat. No. 3,915,923. The resulting products were then compared with Example 6 according to the invention, which was produced according to Process 2 according to the invention. For this, the same theoretical hardnesses were set in each case.

[0135] Experiment 8:

[0136] 260 g of Acclaim® 2200N (OH number 56.1, corresponding to 1 mol) and 1.3 g of Irganox® 1010 are dissolved in 650.03 g of 2-butanone at 56° C. under nitrogen. 64.79 g (2 mol) of MDI are then metered in slowly. This is followed by the addition of 0.69 g of Tyzor AA105 (0.5% solution in Polyether LP 112, corresponding to 10 ppm). The reaction mixture is stirred for approximately 30 min and the temperature should be maintained at 60° C. Thereafter, 11.05 g (1.373 mol) of monoethylene glycol (MEG) are slowly added dropwise to the reaction mixture, and the mixture is stirred for a further 30-60 min at 60° C. Finally, 12.13 g (0.373 mol) of MDI are metered in at 60° C. and the mixture is stirred further at 60° C. until the NCO content no longer changes and hence a complete conversion can be assumed. Thereafter, the solvent 2-butanone is removed as far as possible by vacuum distillation.

TABLE-US-00003 TABLE 3 Results of Comparative Example 8 versus Example 6 according to the invention MDI MDI Tensile Experiment Chain portion portion Theoretical Solution strength number Process Polyol Extended 1 [mol] 2 [mol] hardness viscosity [MPa] 8 According 1 MEG 2 0.373 16 1.054 Processing to U.S. Pat. No. 3915923 not possible 6 2 1 MEG 2 0.373 16 1.333 12

[0137] Experiment 8 was produced according to the process of U.S. Pat. No. 3,915,923. After addition of the chain extender, the mixture had to be stirred for 3 hours in order to obtain complete conversion/until a constant NCO content. After distilling off the solvent, the reaction mixture was nonetheless still highly viscous and not solid at room temperature. The reaction time was very long compared to the reaction time of the process according to the invention (maximum of 3 min). The product not according to the invention could not be processed thermoplastically in an injection moulding machine for further mechanical measurements due to the very low solution viscosity, corresponding to a low molecular weight, and due to the plasticity at room temperature, and is unusable for practical applications and especially for the claimed uses. The polyurethane polymer 6 according to the invention could be processed very well and is suitable for manifold applications, especially for the claimed uses and articles. The polyurethane polymer 6 according to the invention has a Shore hardness of 55A, determined according to DIN ISO 7619-1 (2012-02-01).