Process for the preparation of hydroxyl-functionalized polysiloxanes

A silylated polymer that is the reaction product of a mixture comprising:

• a hydroxyl-functionalized polysiloxane having secondary or tertiary hydroxyl groups, that is the reaction product of a method comprising the steps of:
• i) providing a hydroxyalkyl alkenyl ether having a secondary or tertiary alcohol group, the hydroxylalkyl alkenyl ether conforming to Formula (I)
• wherein n is 0, 1, 2, 3, 4 or 5;
• m is 1, 2, 3, 4 or 5;
• A denotes a spacer group which is constituted by a covalent bond or a C1-C20 alkylene group;
• R1 is selected from hydrogen, a C1-C8 alkyl group, a C3-C10 cycloalkyl group, a C6-C18 aryl group or a C6-C18 aralkyl group;
• Ra, Rb, Rc, Rd, R2, R3, R4 and R5 may be the same or different and each is independently selected from hydrogen, a C1-C8 alkyl group, a C6-C18 aryl group or a C6-C18 aralkyl group, with the proviso that at least one of R3 and R4 is not hydrogen;
• ii) providing a siloxane conforming to Formula (II)
• wherein m is 1, 2, 3, 4 or 5;
• R6, R7, R8 and R9 may be the same or different and each is independently selected from a C1-C8 alkyl group, a C3-C10 cycloalkyl group, a C6-C18 aryl group or a C6-C18 aralkyl group;
• iii) reacting the hydroxyalkyl alkenyl ether having a secondary or tertiary alcohol group with the siloxane under anhydrous conditions and in the presence of a transition metal catalyst of which the transition metal is selected from Groups 8 to 10 of the Periodic Table to provide a reaction product;
• and
• iv) in the presence of the reaction product of step iii), performing a ring opening polymerization of at least one cyclic siloxane monomer having the general Formula (III)
• wherein n is 3, 4, 5, 6, 7 or 8;
• R10 and R11 may the same or different and each is independently selected from hydrogen, a C1-C8 alkyl group, a C2-C8 alkenyl group, a C3-C10 cycloalkyl group, a C6-C18 aryl group or a C6-C18 aralkyl group;
• and
• at least one isocyanatosilane of Formula (VI):
• OCN—B—Si—(X)m(R12)3-m (VI)
• wherein:
• m is 0, 1 or 2;
• each R12 is independently selected from a hydroxyl group, a C1-C10 alkoxy group, a C1-C10 acyloxy group, or —OCH(R13)COOR14, wherein R13 is selected from hydrogen or a C1-C4 alkyl group;
• and R14 is selected from a C1-C8 alkyl group;
• each X is independently selected from a C1-C8 alkyl group which can optionally be interrupted by at least one heteroatom;
• and
• B is selected from a C1-C20 alkylene group.

A silylated polymer that is the reaction product of:

• an NCO-terminated prepolymer that is the reaction product of a hydroxyl-functionalized polysiloxane having secondary or tertiary hydroxyl groups, that is the reaction product of a method comprising the steps of:
• i) providing a hydroxyalkyl alkenyl ether having a secondary or tertiary alcohol group, the hydroxylalkyl alkenyl ether conforming to Formula (I)
• wherein n is 0, 1, 2, 3, 4 or 5;
• m is 1, 2, 3, 4 or 5;
• A denotes a spacer group which is constituted by a covalent bond or a C1-C20 alkylene group;
• R1 is selected from hydrogen, a C1-C8 alkyl group, a C3-C10 cycloalkyl group, a C6-C18 aryl group or a C6-C18 aralkyl group;
• Ra, Rb, Rc, Rd, R2, R3, R4 and R5 may be the same or different and each is independently selected from hydrogen, a C1-C8 alkyl group, a C6-C18 aryl group or a C6-C18 aralkyl group, with the proviso that at least one of R3 and R4 is not hydrogen;
• ii) providing a siloxane conforming to Formula (II)
• wherein m is 1, 2, 3, 4 or 5;
• R6, R7, R8 and R9 may be the same or different and each is independently selected from a C1-C8 alkyl group, a C3-C10 cycloalkyl group, a C6-C18 aryl group or a C6-C18 aralkyl group;
• iii) reacting the hydroxyalkyl alkenyl ether having a secondary or tertiary alcohol group with the siloxane under anhydrous conditions and in the presence of a transition metal catalyst of which the transition metal is selected from Groups 8 to 10 of the Periodic Table to provide a reaction product;
• and
• iv) in the presence of the reaction product of step iii), performing a ring opening polymerization of at least one cyclic siloxane monomer having the general Formula (III)
• wherein n is 3, 4, 5, 6, 7 or 8;
• R10 and R11 may the same or different and each is independently selected from hydrogen, a C1-C8 alkyl group, a C2-C8 alkenyl group, a C3-C10 cycloalkyl group, a C6-C18 aryl group or a C6-C18 aralkyl group;
• with at least one polyisocyanate, wherein there is a stoichiometric excess of the NCO groups of the polyisocyanate with respect to the OH groups of the hydroxyl-functionalized polysiloxane;
• and
• at least one silane having at least one NCO group-reactive functionality.