PROCESS FOR PREPARING POLYESTER ALCOHOLS
The invention relates to a process for preparing polyester alcohols by catalytic reaction of at least one at least polyfunctional carboxylic acid with at least one polyfunctional alcohol and/or by catalytic ring-opening polymerization of cyclic esters in the presence of catalysts, wherein a zeolite is used as catalyst.
1 . A process for preparing polyester alcohols, comprising (i) catalytically reacting at least one polyfunctional carboxylic acid with at least one polyfunctional alcohol, (ii) catalytic ring-opening polymerizing of a cyclic ester, or both (i) and (ii), in the presence of a titanium zeolite catalyst, to obtain a polyester alcohol.
2 . The process according to claim 1 , wherein the titanium zeolite catalyst has a structure selected from the group consisting of a MFI structure, a MOR structure, a BEA structure, a MWW structure, a RRO structure, a LEV structure, a FER structure, a MEL structure, and a MFI/MEL mixed structure.
3 . The process according to claim 1 , wherein the titanium zeolite catalyst has a structure selected from the group consisting of a MFI structure, a MEL structure and a MFI/MEL mixed structure.
4 . The process according to claim 1 , wherein the reacting, the polymerizing, or both, are performed in their entirety in the presence of the titanium zeolite catalyst.
5 . The process according to claim 1 , wherein the titanium zeolite catalyst is in a form of a fixed bed.
6 . The process according to claim 1 , wherein the titanium zeolite catalyst is in a form of a powder.
7 . The process according to claim 1 , comprising:
a) first reacting at least one dicarboxylic acid with at least one polyhydroxyl compound to obtain at least one base polyester alcohol,
b) second reacting the at least one base polyester alcohol, or optionally a mixture of the at least one base polyester alcohol and a further polyhydroxyl compound, in the presence of a titanium zeolite catalyst.
8 . The process according to claim 7 , wherein the first reacting is performed in the presence of an esterification catalyst.
9 . The process according to claim 8 , wherein the esterification catalyst is selected from the group consisting of a toluenesulfonic acid and a metal-organic compound.
10 . The process according to claim 9 , wherein the metal-organic compound comprises titanium or tin.
11 . The process according to claim 9 , wherein the metal-organic compound is at least one selected from the group consisting of titanium tetrabutoxide, tin (II) octoate, dibutyltin laurate, and tin chloride.
12 . The process according to claim 7 , wherein the second reacting is performed continuously.
13 . A method of producing polyurethanes, comprising reacting the polyester alcohol of claim 1 with an isocyanate.
14 . The process of claim 1 , comprising (i) catalytically reacting at least one polyfunctional carboxylic acid with at least one polyfunctional alcohol in the presence of a titanium zeolite catalyst.
15 . The process of claim 1 , comprising (ii) catalytic ring-opening polymerizing of a cyclic ester in the presence of a titanium zeolite catalyst.
16 . The process of claim 15 , wherein the cyclic ester is ε-caprolactone.
17 . The process of claim 6 , wherein the titanium zeolite catalyst is present in an amount of 0.001 to 1% by weight, based on the weight of the polyester alcohol.
18 . The process of claim 6 , wherein the titanium zeolite catalyst is present in an amount of 0.15 to 0.25% by weight, based on the weight of the polyester alcohol.
19 . The process of claim 7 , wherein the at least one base polyester alcohol and the further polyhydroxyl compound together have a water content of less than 0.1% by weight.
20 . The process of claim 7 , wherein the at least one base polyester alcohol and the further polyhydroxyl compound together have a water content of less than 0.01% by weight.