Process for preparing a polyurethane using a polyester polyol comprising polycyclic aromatic moieties

A process for preparing a polyisocyanate polyaddition product, the process comprising:

• reacting at least a polyisocyanate composition (C-I) comprising polyisocyanate and a composition (C-II) comprising a compound (C-A) having at least two hydroxyl groups which are reactive towards isocyanate groups, wherein the compound (C-A) has a molecular weight of 500 g/mol or more and comprises polycyclic aromatic moieties, thereby producing a first product, and
• reacting the first product with a compound (C-C) having at least two functional groups which are reactive towards isocyanate groups as a chain extender, wherein the compound (C-C) has a molecular weight ranging from 49 g/mol to 499 g/mol,
• wherein compound (C-A) is a polyester polyol and the polycyclic aromatic moieties of the compound (C-A) comprise at least one polyol selected from the group consisting of alkoxylated 1,4-dihydroxynaphthalene, alkoxylated 1,5-dihydroxynaphthalene, and alkoxylated 1,8-dihydroxynaphthalene,
• the polyisocyanate is an aromatic polyisocyanate, and
• the polyisocyanate polyaddition product is a thermoplastic polyurethane;
• and
• the polyester polyol as compound (C-A) has a content of from 10 to 40 wt % of at least one of the polyols, with respect to the total weight of polyester polyol as compound (C-A).

A polyisocyanate polyaddition product, obtained by a process comprising:

• reacting at least a polyisocyanate composition (C-I) comprising an aromatic polyisocyanate and a composition (C-II) comprising a compound (C-A) having at least two hydroxyl groups which are reactive towards isocyanate groups, wherein the compound (C-A) has a molecular weight of 500 g/mol or more and comprises polycyclic aromatic moieties thereby producing a first product, and
• reacting the first product with a compound (C-C) having at least two functional groups which are reactive towards isocyanate groups as a chain extender, wherein the compound (C-C) has a molecular weight ranging from 49 g/mol to 499 g/mol,
• wherein compound (C-A) is a polyester polyol and the polycyclic aromatic moieties of the compound (C-A) comprise alkoxylated 1,5-dihydroxynaphthalene,
• wherein the polyisocyanate polyaddition product is a thermoplastic polyurethane,
• composition (C-II) further comprises at least one secondary polyol different from the polyester polyol of compound (C-A), wherein the weight ratio of the compound (C-A) to the at least one secondary polyol is from 10:90 to 20:80, and
• the at least one secondary polyol is a polyester polyol different from the compound (C-A).