Thermoplastic polyurethane for seal applications

Patent metadata

Field	Value
Publication number	US-2016333134-A1
Application number	US-201415104540-A
Country	US
Kind code	A1
Filing date	Dec 1, 2014
Priority date	Dec 17, 2013
Publication date	Nov 17, 2016
Grant date	—

Abstract

A thermoplastic polyurethane is obtained via reaction of isocyanates (a) with a polyol component (b) having at least one polyesterdiol (b1), at least one polyetherdiol (b2) and at least one polycarbonatediol (b3), in each case with a molar mass of from 500 to 5000 g/mol, and also with at least one diol with a molar mass of from 62 to 500 g/mol. The thermoplastic polyurethane can be used for producing moldings, more particularly seals, coupling stars, valves, and profiles. The polyurethane has exceptional mechanical and chemical properties.

First claim

1 . A thermoplastic polyurethane, obtained by a process comprising reacting reagents comprising
(a) a isocyanate with a (b) a polyol component comprising a polyester diol (b1), a polyether diol (b2) and a polycarbonate diol (b3), each having a molecular weight in a range of from 500 to 5000 g/mol, and (c) a diol having a molecular weight of from 62 g/mol to 500 g/mol.

2 . The polyurethane of claim 1 , wherein the reagents further comprise a trifunctional cross-linker (d) having a molecular weight of from 64 g/mol to 500 g/mol.

3 . The polyurethane of claim 1 , wherein the molecular weight of the polyol component (b) is in the range of from 1000 g/mol to 3000 g/mol.

4 . The polyurethane of claim 1 , wherein at least two diols of the polyol component (b) are present in the form of a copolymer having a molecular weight of from 500 to 5000 g/mol.

5 . The polyurethane of claim 1 , wherein a proportion of polyether diol (b2) in the polyol component (b) is from 10 mol % to 80 mol %,
wherein a proportion of polycarbonate diol (b3) in the polyol component (b) is from 10 mol % to 80 mol %, and wherein a remainder of the polyol component (b) is formed by the polyester diol (b1).

6 . The polyurethane of claim 1 , wherein the polyester diol (b1) comprises a diol having a molecular weight in a range of from 1500 to 2500 g/mol.

7 . The polyurethane of claim 1 , wherein the polyester diol (b1) comprises polycaprolactone.

8 . The polyurethane of claim 1 , wherein the polyether diol (b2) comprises a diol having a molecular weight in a range of from 1500 g/mol to 2500 g/mol.

9 . The polyurethane of claim 1 , wherein the polyether diol (b2) comprises, in reacted form, ethylene oxide, propylene oxide, and/or a hydroxyl-group-containing polymerization product of tetrahydrofuran.

10 . The polyurethane of claim 1 , wherein the polycarbonate diol (b3) comprise a diol having a molecular weight in a range of from 1500 g/mol to 2500 g/mol.

11 . The polyurethane of claim 1 , wherein the polycarbonate diol (b3) comprises, in reacted form, 1,6-hexanediol, 1,9-nonanediol, and/or 1,5-pentanediol.

12 . A process for producing the polyurethane of claim 1 , comprising:
(A) preparing a mixture comprising a polyester diol (b1), a polyether diol (b2) and a polycarbonate diol (b3), each having a molecular weight of from 500 to 5000 g/mol; (B) adding an organic diisocyanate (a) to the mixture from (A) in an amount such that an equivalence ratio of NCO groups to NCO-reactive groups is from 2.5:1 to 10:1, to obtain a reaction mixture; (C) reacting the reaction mixture prepared in (B) at a temperature of >80° C. to form an NCO-terminated prepolymer; (D) reacting the NCO-terminated prepolymer prepared in (C) with one or more chain extenders (c) having a molecular weight in a range of from 62 g/mol to 500 g/mol, to form a thermoplastic polyurethane, wherein component (c) is used in an amount such that, taking into consideration all the components, an equivalence ratio of NCO groups to NCO-reactive groups of from 0.9:1.0 to 1.2:1.0 is established.

13 . A process of producing a molded body, the process comprising:
contacting the polyurethane of claim 1 with a mold.

14 . The process of claim 13 , wherein the molded body includes a seal.

15 . The process of claim 14 , wherein the seal is adapted for hydraulic and pneumatic applications.

16 . The polyurethane of claim 1 , wherein at least two diols of the polyol component (b) are present in the form of a copolymer having a molecular weight in the range of from 1000 g/mol to 3000 g/mol.

17 . The polyurethane of claim 1 , wherein the polyester diol (b1) comprises only diols having a molecular weight of from 1500 to 2500 g/mol.

18 . The polyurethane of claim 1 , wherein the polyether diol (b2) comprises only diols having a molecular weight of from 1500 g/mol to 2500 g/mol.

19 . The polyurethane of claim 1 , wherein the polyether diol (b2) comprises, in reacted form, ethylene oxide.

20 . The polyurethane of claim 1 , wherein the polycarbonate diol (b3) comprise only diols having a molecular weight in a range of from 1500 g/mol to 2500 g/mol.

Assignees

• Freudenberg Carl Kg

Inventors

• Hieber Juergen
• Freitag Edgar
• Goerres Martin Franz
• Burkert Mathias
• Barillas Gonzalo
• Jaeckel Juergen

Classifications

• C08G18/4269

  Lactones · CPC title

• C08G18/44

  Polycarbonates · CPC title

• C08G18/4018

  Mixtures of compounds of group C08G18/42 with compounds of group C08G18/48 · CPC title

• C08G18/4854

  Polyethers containing oxyalkylene groups having four carbon atoms in the alkylene group · CPC title

• C08G18/4833

  Polyethers containing oxyethylene units · CPC title