Method for producing a cross-linked siloxane network

Patent metadata

Field	Value
Publication number	US-10654976-B2
Application number	US-201715785804-A
Country	US
Kind code	B2
Filing date	Oct 17, 2017
Priority date	Dec 13, 2016
Publication date	May 19, 2020
Grant date	May 19, 2020

Abstract

A method for producing a cross-linked siloxane network comprises the steps of: (a) providing a first part comprising (i) a first siloxane compound comprising at least one cyclic siloxane moiety and (ii) a second siloxane compound comprising a plurality of siloxane moieties, (b) providing a second part, the second part comprising a hydroxide salt, (c) combining the first part and the second part to produce a reaction mixture, (d) heating the reaction mixture to a temperature sufficient for the hydroxide salt to open the ring of the cyclic siloxane moiety, and (e) maintaining the reaction mixture at an elevated temperature so that at least a portion of the opened cyclic siloxane moieties react to produce a cross-linked siloxane network.

First claim

What is claimed is:

1. A method for producing a cross-linked siloxane network, the method comprising the steps of:
(a) providing a first part comprising (i) a first siloxane compound comprising at least one cyclic siloxane moiety and (ii) a second siloxane compound comprising a plurality of siloxane moieties, wherein 50 mol. % or more of the siloxane moieties in the second siloxane compound are selected from the group consisting of moieties of Formula (LXXX) and moieties of Formula (XC)

wherein R 81 , R 82 , and R 91 are independently selected from the group consisting of haloalkyl groups, aralkyl groups, aryl groups, substituted aryl groups, heteroaryl groups, and substituted heteroaryl groups, wherein about 25 mol. % or more of the siloxane moieties in the second siloxane compound are moieties of Formula (XC), and wherein about 10 mol. % or more of silicon atoms in the second siloxane compound have one or more hydroxy groups covalently bound thereto; and wherein Formula (LXXX) constitutes a D unit and Formula (XC) constitutes a T unit;
(b) providing a second part, the second part comprising a hydroxide salt;
(c) combining the first part and the second part to produce a reaction mixture;
(d) heating the reaction mixture to a temperature sufficient for the hydroxide salt to open the ring of the cyclic siloxane moiety; and
(e) maintaining the reaction mixture at an elevated temperature so that at least a portion of the opened cyclic siloxane moieties react to produce a cross-linked siloxane network.

2. The method of claim 1 , wherein the first siloxane compound comprises at least two cyclic siloxane moieties.

3. The method of claim 2 , wherein the first siloxane compound comprises cyclic siloxane moieties conforming to the structure of Formula (XL)

wherein R 41 and R 42 are independently selected from the group consisting of alkyl groups, substituted alkyl groups, cycloalkyl groups, substituted cycloalkyl groups, alkenyl groups, substituted alkenyl groups, cycloalkenyl groups, substituted cycloalkenyl groups, heterocyclyl groups, substituted heterocyclyl groups, aryl groups, substituted aryl groups, heteroaryl groups, and substituted heteroaryl groups; and R 43 and R 44 are independently selected from the group consisting of haloalkyl groups, aralkyl groups, aryl groups, substituted aryl groups, heteroaryl groups, and substituted heteroaryl groups.

4. The method of claim 3 , wherein the first siloxane compound comprises at least three cyclic siloxane moieties conforming to the structure of Formula (XL).

5. The method of claim 1 , wherein R 81 , R 82 , and R 91 are independently selected from the group consisting of aryl groups.

6. The method of claim 5 , wherein R 81 , R 82 , and R 91 are phenyl groups.

7. The method of claim 1 , wherein about 15 mol. % or more of silicon atoms in the second siloxane compound have one or more hydroxy groups covalently bound thereto.

8. The method of claim 1 , wherein the hydroxy groups constitute about 1% to about 10% of the mass of the second siloxane compound.

9. The method of claim 1 , wherein the second siloxane compound has a number average molar mass of about 500 g/mol or more.

10. The method of claim 1 , wherein the first part further comprises a third siloxane compound, and the third siloxane compound comprises at least one cyclic siloxane moiety.

11. The method of claim 10 , wherein the third siloxane compound is selected from the group consisting of compounds conforming to the structure of Formula (X)

wherein R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 , R 18 , and R 19 are independently selected from the group consisting of alkyl groups, substituted alkyl groups, cycloalkyl groups, substituted cycloalkyl groups, alkenyl groups, substituted alkenyl groups, cycloalkenyl groups, substituted cycloalkenyl groups, heterocyclyl groups, substituted heterocyclyl groups, aryl groups, substituted aryl groups, heteroaryl groups, substituted heteroaryl groups, and siloxy groups; at least one of R 7 and R 8 is different from each of R 2 , R 3 , R 4 , R 5 , and R 6 ; at least one of R 16 and R 17 is different from each of R 13 , R 14 , R 15 , R 18 , and R 19 ; and the variable n is selected from the group consisting of integers equal to or greater than 1.

12. The method of claim 10 , wherein the third siloxane compound is selected from the group consisting of compounds conforming to the structure of Formula (XX)

wherein the variables a, b, c, and d are integers selected from the group consisting of 0 and 1; the sum of a and b is equal to 1; the sum of c and d is equal to 1; R 21 , R 22 , R 23 , R 24 , R 25 , R 26 , and R 27 are independently selected from the group consisting of alkyl groups, substituted alkyl groups, cycloalkyl groups, substituted cycloalkyl groups, alkenyl groups, substituted alkenyl groups, cycloalkenyl groups, substituted cycloalkenyl groups, heterocyclyl groups, substituted heterocyclyl groups, aryl groups, substituted aryl groups, heteroaryl groups, substituted heteroaryl groups, and siloxy groups; and at least one of R 21 and R 22 is different from each of R 23 , R 24 , R 25 , R 26 , and R 27 .

13. The method of claim 1 , wherein the hydroxide salt comprises a cation selected from the group consisting of a lithium cation, a sodium cation, a potassium cation, ammonium cations, and phosphonium cations.

14. The method of claim 13 , wherein the cation is selected from the group consisting of ammonium cations and phosphonium cations.

15. The method of claim 14 , wherein the hydroxide salt is selected from the group consisting of tetramethylammonium hydroxide, tetrabutylammonium hydroxide, tetrabutylphosphonium hydroxide, and mixtures thereof.

16. The method of claim 15 , wherein the hydroxide salt is tetrabutylphosphonium hydroxide.

17. The method of claim 1 , wherein the reaction mixture is heated to a temperature of about 70° C. or more.

Assignees

• Milliken & Co

Inventors

• Wang Yunzhang
• Yu Xinfei
• Stapleton Russell A
• Wilson Michael E
• Torres Eduardo
• Srivastava Sudhanshu
• Lawson Richard
• Hanssen Robbie W J M

Classifications

• C08G77/16

  to hydroxy groups · CPC title

• C08L83/04

  Polysiloxanes · CPC title

• C08G77/08 Primary

  characterised by the catalysts used · CPC title

• C08G77/80

  Siloxanes having aromatic substituents, e.g. phenyl side groups · CPC title

• C08G77/045

  containing less than 25 silicon atoms · CPC title