Process for preparing hydrogen siloxane copolymers

• US 5,698,654 A
• Filed: 07/30/1996
• Issued: 12/16/1997
• Est. Priority Date: 07/30/1996
• Status: Expired due to Fees

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Nye, Susan A., Wutzer, Brenda S., Riccio, Donna A.
• Primary Examiner(s): DEAN JR, RALPH H
• Application Number:
  US08/688,578
• Time in Patent Office: 504 Days
• Field of Search: 528/21, 528/37, 528/14, 528/23
• US Class Current: 528/21
• CPC Class Codes: C08G 77/08 characterised by the catalysts used
• CPC Class Codes: C08G 77/12 containing silicon bound to hydrogen C08G77/045 takes precedence
• CPC Class Codes: C08G 77/20 containing silicon bound to unsaturated aliphatic groups C08G77/045 takes precedence
• CPC Class Codes: C08G 77/28 sulfur-containing groups

Abstract

A sequential catalysis of the ring opening polymerization of cyclic organosiloxanes using a base catalyst that can be neutralized by a subsequent redistribution and condensation catalyst such as a Lewis acid catalyst, preferably a phosphonitrilic compound, permits the rapid synthesis of functionalized and poly-functionalized silicone copolymers such as alkenyl hydride copolymers, a new composition of matter.

Claims

1. A process for the production of siloxane copolymers comprising:

(a) polymerization of a cyclic siloxane and an M rich siloxane in the presence of a basic catalyst to produce a polymeric siloxane;

(b) neutralization of the basic catalyst with an excess of a catalytic Lewis acid compound; and

(c) reacting a second siloxane with the polymeric siloxane in the presence of the catalytic Lewis acid compound producing thereby a copolymeric siloxane.

2. The process of claim 1 wherein the catalytic Lewis acid compound is a phosphonitrilic compound selected from the group consisting of(X₃ P(NPX₂)_n PX₃)⁺ PX₆^- where n is an integer of from 1 to 6 and X is a halide;

2) (X₃ P(NPX₂)_n NPX₃)⁺ PX₆^- where n is an integer of from 1 to 6 and X is a halide;

3) (X₃ P(NPX₂)_n NPX₃)⁺ EX_m^- where E is an element having an electronegativity value of from 1.2 to 2 with m an integer of from 3 to 8 and X is a halide;

4) O(X)_2-a Y_a P(NPX₂)_b NPX_3-c Y_c where b is an integer ranging from 0 to 8, a is 0 or 1, c is 0 or 1, Y is OH, OR'"'"' or R'"'"'CO₂ where R'"'"' is alkyl or aryl and X is a halide;

5) O(X)_2-a Y_a P(NPX₂)_b NP(O)X_2-c Y_c where b is an integer ranging from 0 to 8, a is 0 or 1, c is 0 or 1, Y is OH, OR'"'"' or R'"'"'CO₂ where R'"'"' is alkyl or aryl and X is a halide;

6) X_3-p (HO)_p P(NPX₂)_m NP(O)X₂, where m is an integer ranging from 0 to 6 and p is 0 or 1 and X is a halide; and

7) X₃ P(NPX₂)_m NPX₂ (O) where m values can vary from 0 to 6 and X is a halide.

3. The process of claim 2 where X is selected from the group consisting of F, Cl, Br, and I.

4. The process of claim 3 where E is selected from the group consisting of Al, Sb, P, Sn, Zn and Fe.

5. The process of claim 4 where the phosphonitrilic compound has the formula (X₃ P(NPX₂)_n PX₃)⁺ PX₆^-.

6. The process of claim 5 where n=2.

7. The process of claim 6 where X is Cl.

8. The process of claim 7 where the M rich compound comprises M groups having the formula:

M=R⁴ R⁵ R⁶ SiO_1/2

where R⁴, R⁵ and R⁶ are each independently selected from the group consisting of hydrogen and one to forty carbon atom monovalent hydrocarbon radicals subject to the limitation that at least one of R⁴, R⁵ and R⁶ is a two to forty carbon atom monovalent alkenyl hydrocarbon radical.

9. The process of claim 8 where the second siloxane comprises a hydrogen organosiloxane compound.

10. A process for the production of siloxane copolymers consisting essentially of:

(a) polymerization of a cyclic siloxane and an M rich siloxane in the presence of a basic catalyst to produce a polymeric siloxane;

(b) neutralization of the basic catalyst with an excess of a catalytic Lewis acid compound; and

(c) reacting a second siloxane with the polymeric siloxane in the presence of the catalytic Lewis acid compound producing thereby a copolymeric siloxane.