Catalysts for polycondensation and redistribution of organosiloxane polymers

A process for the polycondensation of low molecular weight organopolysiloxanediols having an average degree of substitution of from 1.9 to 2.1 organic groups attached to silicon per silicon atom, said process comprising carrying out said polycondensation in the presence of an effective catalytic amount of a phosphazene compound of the general formula (Ia) or (Ib):

• O(X).sub.2-m Y.sub.m P{NP(X).sub.2 }.sub.n NP(X).sub.3-q (Y).sub.q(Ia)
• O(X).sub.2-m Y.sub.m P{NP(X).sub.2 }.sub.n N(H)P(O)(X).sub.2-p (Y).sub.p(Ib)
• where n=0 or an integer from 1 to 8;
• m=0 or an integer of 1;
• p=0 or an integer of 1;
• q =0 or an integer of from 1 to 2;
• X=halogen;
• Y=OH, OR, O(O)CR, wherein R is alkyl or aryl.

A process for the polycondensation of low molecular weight organopolysiloxanediols having an average degree of substitution of from 1.9 to 2.1 organic groups attached to silicon per silicon atom, said process comprising carrying out said polycondensation in the presence of an effective catalytic amount of a phosphazene compound of the general formula (Ic), (Id) or (Ie):

• OCl.sub.2 P(NPCl.sub.2).sub.n NPCl.sub.2 OH, (Ic)
• OCl.sub.2 P(NPCl.sub.2).sub.n N(H)PCl.sub.2 O, (Id)
• OCl.sub.2 P(NPCl.sub.2).sub.n NPCl.sub.3, (Ie)
• where n is 0 or an integer of from 1 to 8.

A process for deactivating after polycondensation or redistribution a catalyst comprising a phosphazene of the general formula (Ia) or (Ib):

• O(X).sub.2-m Y.sub.m P{NP(X).sub.2 }.sub.n NP(X).sub.3-q (Y).sub.q(Ia)
• O(X).sub.2-m Y.sub.m P{NP(X).sub.2 }.sub.n N(H)P(O)(X).sub.2-p (Y).sub.p(Ib)
• where n=0 or an integer from 1 to 8;
• m=0 or an integer of 1;
• p=0 or an integer of 1;
• q =0 or an integer of from 1 to 2;
• X=halogen;
• Y=OH, OR, O(O)CR, Wherein R is alkyl or aryl, said process comprising heating the final product at temperature above 170.degree. C. for a time sufficient to deactivate said catalyst and thereby to thermally-stabilize said final product.

A process for deactivating after polycondensation or redistribution a catalyst comprising a phosphazene of the general formula (Ia) or Ib):

• O(X).sub.2-m Y.sub.m P{NP(X).sub.2 }.sub.n NP(X).sub.3-q (Y).sub.q(Ia)
• O(X).sub.2-m Y.sub.m P{NP(X).sub.2 }.sub.n N(H)P(O)(X).sub.2-p (Y).sub.p(Ib)
• where n=O or an integer from 1 to 8;
• m=0 or an integer of 1;
• p=0 or an integer of 1;
• q=0 or an integer of from 1 to 2;
• X=halogen;
• Y=OH, OR, O(O)CR, wherein, R is alkyl or aryl, said process comprising heating the final product with a basic nitrogen compound selected from ammonia, amines, organosilazanes, mixtures thereof and the like, for a time sufficient to deactivate said catalyst and thereby to thermally-stabilize said final product.

A process for deactivating after polycondensation or redistribution a catalyst comprising a phosphazene of the general formula (Ia) or (Ib):

• O(X).sub.2-m Y.sub.m P{NP(X).sub.2 }.sub.n NP(X).sub.3-q (Y).sub.q(Ia)
• O(X).sub.2-m Y.sub.m P{NP(X).sub.2 }.sub.n N(H)P(O)(X).sub.2-p (Y).sub.p(Ib)
• where n=0 or an integer from 1 to 8;
• m=0 or an integer of 1;
• p=0 or an integer of 1;
• q =0 or an integer of from 1 to 2;
• X=halogen;
• Y=OH, OR, O(O)CR, wherein R is alkyl or aryl, said process comprising heating the final product with a strong basic compound selected from a metal oxide, a metal hydroxide, a metal carbonate, where the metal is selected from mono-, di- and trivalent metals comprising lithium, sodium, magnesium, calcium, barium, zinc and aluminum, butyllithium, lithium bis(trimethylsilyl)amide, or a mixture of any of them, for a time sufficient to deactivate said catalyst and thereby to thermally-stabilize said final product.