Method for preparing a thermoplastic polyurethane having a low glass transition temperature

Patent metadata

Field	Value
Publication number	US-2020362086-A1
Application number	US-201816766180-A
Country	US
Kind code	A1
Filing date	Dec 13, 2018
Priority date	Dec 14, 2017
Publication date	Nov 19, 2020
Grant date	—

Abstract

The present invention is directed to a method for preparing a thermoplastic polyurethane having a low glass transition temperature. The process according to the present invention comprises the steps of providing at least one polyol composition (P) comprising a poly-s-caprolactone polyol (P1), and a second polyol (P2) which is different from the first polyol (P1), and reacting the at least one polyol composition (P) with at least one polyisocyanate (P1) and at least one low molecular weight diol (CE) optionally in the presence of at least one catalyst (CA) and/or at least one additive (AD) to obtain a thermoplastic polyurethane. The present invention is also directed to the thermoplastic polyurethane obtained according to the process of the prestn invention and the use thereof in extruded articles and injection molded articles.

First claim

1 : A method for preparing a thermoplastic polyurethane, the method comprising:
(A) providing at least one polyol composition (P) comprising
a poly-ε-caprolactone polyol (P1), and
a polyol (P2) which is different from the poly-ε-caprolactone polyol (P1);
(B) reacting the at least one polyol composition (P) of (A) with at least one polyisocyanate (PI) and at least one low molecular weight diol (CE) optionally in the presence of at least one catalyst (CA) and/or at least one additive (AD) to obtain a thermoplastic polyurethane, wherein the at least one polyol composition (P) has a number average molecular weight Mn in a range of ≥1500 g/mol to ≤10,000 g/mol determined according to DIN 55672-1:2016-03, wherein the at least one low molecular weight diol (CE) has a molecular weight in a range of ≥50 g/mol to ≤350 g/mol, and wherein in (A) the poly-ε-caprolactone polyol (P1) is obtained by reacting ε-caprolactone (P11) and a starter molecule (P12) having a number average molecular weight in a range of ≥80 g/mol to ≤1500 g/mol determined according to DIN 55672-1: 2016-03, wherein the starter molecule (P12) is selected from the group consisting of neopentyl glycol, 1,4-butanediol, 1,6-hexanediol, polyethylene glycol, polypropylene glycol, α-hydro-ω-hydroxypoly(oxytetra-methylene) diol and α-hydro-ω-hydroxypoly(oxytri-methylene) diol.

2 : The method of claim 1 , wherein the thermoplastic polyurethane obtained has a T g in a range of ≥−60° C. to ≤10° C. determined by dynamic mechanical thermal analysis according to DIN EN ISO 6721-1:2011-08 at a heating rate of 2 K/min and 1 Hz torsion mode.

3 : The method of claim 1 , wherein a weight ratio between the poly-ε-caprolactone polyol (P1) and the polyol (P2) in the at least one polyol composition (P) is in a range of ≥1:5 to ≤10:1.

4 : The method of claim 1 , wherein the poly-ε-caprolactone polyol (P1) has a number average molecular weight in a range of ≥1500 g/mol to ≤2500 g/mol determined according to DIN 55672-1: 2016-03.

5 : The method of claim 1 , wherein the polyol (P2) has a number average molecular weight Mn in a range of ≥1000 g/mol to ≤4000 g/mol determined according to DIN 55672-1: 2016-03.

6 - 7 . (canceled)

8 : The method of claim 1 , wherein the poly-ε-caprolactone polyol (P1) in (A) has a weight ratio between the ε-caprolactone (P11) and a starting molecule (P12) in a range of ≥1:10 to ≤10:1.

9 : The method of claim 1 , wherein the polyol (P2) is selected from the group consisting of a polyether polyol, polyester polyol and polycarbonate polyol.

10 : The method of claim 1 , wherein in (B) the at least one polyisocyanate (PI) is selected from the group consisting of 2,2′-, 2,4′- and 4,4′-diphenylmethane diisocyanate, 2,4- and 2,6-toluene diisocyanate, 1,2-, 1,3- and 1,4-cyclohexane diisocyanates, hexamethylene 1,6-diisocyanate, 2-methyl-1,5-pentamethylene diisocyanate, pentamethylene 1,5-diisocyanate, tetramethylene 1,4-diisocyanate, isophorone diisocyanate, p-phenyl diisocyanate, o-tolidine diisocyanate and 1,5-naphthalene diisocyanate and 4,4′-diisocyanatdicyclohexylmethane.

11 : The method of claim 1 , wherein in (B) the at least one low molecular weight diol (CE) is selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, hydroquinone bis 2-hydroxyethyl ether and bis-2(hydroxy ethyl)-terephthalate.

12 : The method of claim 1 , wherein in (B) the at least one additive (AD) is selected from the group consisting of an antioxidant, a hydrolysis stabilizer, a light stabilizer, a UV absorber, a blowing agent and other process stabilizers.

13 : The method of claim 1 , wherein in (B) a molar ratio between the at least one polyol composition (P) and the at least one polyisocyanate (PI) is in a range of ≥0.1:1 to ≤1:1.

14 : A thermoplastic polyurethane obtained or obtainable by the method of claim 1 .

15 : A thermoplastic polyurethane obtained by the method of claim 1 , wherein the thermoplastic polyurethane has a T g in a range of ≥−60° C. to ≤10° C. determined by dynamic mechanical thermal analysis according to DIN EN ISO 6721-1:2011-08 at a heating rate of 2 K/min and 1 Hz torsion mode and a hard segment fraction in a range of ≥0.1 to ≤0.7, the hard segment fraction being defined by the formula:

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Assignees

• Basf Se

Inventors

• Poppenberg Johannes
• Richter Sebastian
• Poeselt Elmar

Classifications

• C08G2110/0058

  ≥50 and <150kg/m3 · CPC title

• C08G2110/0066

  ≥ 150kg/m3 · CPC title

• C08G18/664 Primary

  with compounds of group C08G18/3203 · CPC title

• C08G18/4277

  Caprolactone and/or substituted caprolactone · CPC title

• C08J2375/04

  Polyurethanes · CPC title