Patent ID: 7176264

Claim:
A process for manufacture of a dendritic polyether comprising a core, derived from a compound having two or more hydroxyl groups, and at least one branching generation being built up from at least one hydroxyoxetane having one oxetane group and at least one hydroxyl group, said process comprising ring opening addition to said core and ring opening polymerization of said oxetane, wherein a mixture of said compound having said two or more hydroxyl groups and at least one cationic initiator is prepared and optionally heated to 90–130° C., that said hydroxyoxetane is fed to said mixture at a rate resulting in and/or maintaining a reaction temperature, during said ring opening addition and said ring opening polymerization, being below onset at thermal degradation and in an amount resulting in said at least one branching generation, that said initiator is present in an amount of 0.1–0.5% by weight calculated on said core and said hydroxyoxetane, preferably in an amount giving a ratio of hydroxyl groups to initiator of between 1:0.01 and 1:0.05, and that yielded dendritic polyether is neutralized by addition of at least one alkaline compound and optionally purified, wherein said compound having said at least two hydroxyl groups is 5,5-dihydroxyalkyl-1,3-dioxane, a 5,5-di(hydroxyalkoxy)-1,3-dioxane, a 5,5-di(hydroxyalkoxyalkyl)-1,3-dioxane, a 2-alkyl-1,3-propanediol, a 2,2-dialkyl-1,3-propanediol, a 2-hydroxy-1,3-propanediol, a 2,2-dihydroxy-1,3-propanediol, a 2-hydroxy-2-alkyl-1,3-propanediol, a 2-hydroxyalkyl-2-alkyl-1-,3-propanediol, a 2,2-di(hydroxyalkyl)-1,3-propanediol, a 2-hydroxy-alkoxy-2-alkyl-1,3-propanediol, a 2,2-di(hydroxyalkoxy)-1,3-propanediol, a 2-hydroxyalkoxyalkyl-2-alkyl-1,3-propanediol or a 2,2-di(hydroxyalkoxyalkyl)-1,3-propanediol and, wherein said alkyl is C 1 –C 24 linear or branched alkyanyl or alkenyl and that said alkoxy is selected from the group consisting of ethoxy, propoxy, butoxy, phenylethoxy nominally comprising 0.2–20 alkoxy units or is a combination of two or more of said alkoxy nominally comprising 0.2–10 units of respective alkoxy and nominally comprising a total of 0.2–20 alkoxy units and obtaining the dendritic polyether.