POLYETHER-POLYSILOXANE GRADIENT COPOLYMERS

The invention relates to a polyether-polysiloxane copolymer having a number average molecular weight (Mn) of 500-50,000 g/mol, a polydispersity index of 1.0-2.0, and an unsaturation value of less than 0,02 meq/g, wherein said copolymer is a gradient copolymer.The invention also relates to a two-component (2K) composition comprising at least one component (I) and at least one component (II), wherein component (I) comprises at least one compound having at least one hydroxyl group-reactive functionality preferably selected from isocyanate groups, cyano groups, melamine groups, epoxy groups, acrylate groups, methacrylate groups, ester groups, carbonate groups, cyclocarbonate groups, carboxylic acid groups or anhydride groups, most preferably selected from isocyanate groups, and component (II) comprises a hydroxyl-functionalized polyether-polysiloxane copolymer according to the invention.The invention further relates to a method for producing a polyether-polysiloxane copolymer according to the invention, wherein a mixture of at least one alkylene oxide and at least one siloxane is polymerized in the presence of a Double Metal Cyanide (DMC) catalyst.Finally, the invention also relates to use of the polyether-polysiloxane copolymer according to the invention, a two-component (2K) composition according to the invention or copolymers obtainable by the method of according to the invention as a reactive component for coating, sealant or adhesive compositions based on active hydrogen reactive compounds.