Method for preparing a functionalized polyorganosiloxane

Patent metadata

Field	Value
Publication number	US-12371536-B2
Application number	US-202418605013-A
Country	US
Kind code	B2
Filing date	Mar 14, 2024
Priority date	Dec 21, 2018
Publication date	Jul 29, 2025
Grant date	Jul 29, 2025

Abstract

A method for preparing functionalized polyorganosiloxanes is disclosed. The method includes 1) combining starting materials including A) a boron-containing Lewis acid catalyst, and B) an organosilicon compound having an average, per molecule of at least 1 silicon bonded groups of the formula —OR 2 ; wherein each R 2 is an independently selected monovalent hydrocarbon group of 1 to 6 carbon atoms, thereby forming a catalyzed mixture; and thereafter 2) adding the catalyzed mixture into a starting material including C) an organohydrogensiloxane having at least 1 silicon bonded hydrogen atom per molecule, thereby preparing a product comprising the functionalized polyorganosiloxane and a by-product comprising HR 2 .

First claim

The invention claimed is:

1. A method for preparing a functionalized polyorganosiloxane comprising:
1) Combining starting materials comprising
A) a boron-containing Lewis acid, and
B) an organosilicon compound having an average, per molecule of at least 1 silicon bonded group of the formula —OR 2 ; wherein each R 2 is an independently selected monovalent hydrocarbon group of 1 to 6 carbon atoms, thereby forming a catalyzed mixture,
wherein the starting materials in step 1) are free of SiH functional organosilicon compounds; and thereafter

2) adding the catalyzed mixture into a starting material comprising
C) an organohydrogensiloxane having at least 1 silicon bonded hydrogen atom per molecule, thereby preparing a product comprising the functionalized polyorganosiloxane and a by-product comprising HR 2 ,
where in steps 1) and 2) of this method, the boron containing Lewis acid is provided in a total amount of 50 ppm to 600 ppm, based on combined weights of the organosilicon compound and the organohydrogensiloxane.

2. The method of claim 1 , where step 2) is performed at a temperature of 5° C. to 40° C.

3. The method of claim 1 , where the method is performed at a temperature of 5° C. to 70° C.

4. The method of claim 1 , where the catalyzed mixture in step 1) is heated to 40° C. to 70° C. before step 2).

5. The method of claim 4 , where the catalyzed mixture is cooled to less than 40° C. in step 2).

6. The method of claim 1 , where the method is performed at a temperature of 10° C. to <25° C.

7. The method of claim 1 , where B) the organosilicon compound is selected from the group consisting of:
an alkoxysilane of formula: R 1 (4-a) SiOR 2 a , where each R 1 is independently selected from the group consisting of a monovalent hydrocarbon group and a monovalent halogenated hydrocarbon group, each R 2 is a monovalent hydrocarbon group of 1 to 6 carbon atoms, and subscript a is 1 to 4;

an organosiloxane of formula: R 3 2 R X SiO—(R 3 2 SiO) b —SiR X R 3 2 , where each R 3 is independently selected from the group consisting of a monovalent hydrocarbon group and a monovalent halogenated hydrocarbon group, each R X is the group of formula —OR 2 , and subscript b≥1; and
a resin of unit formula: (R 1 SiO 3/2 ) m (R 1 R X SiO 2/2 ) n (R 1 R X 2 SiO 1/2 ) z ,

where subscript m is 0 to 20, subscript n is 1 to 20, subscript z is 0 to 20, each R 1 is independently selected from the group consisting of a monovalent hydrocarbon group and a monovalent halogenated hydrocarbon group, and each R X is the group of formula —OR 2 .

8. The method of claim 1 , where C) the organohydrogensiloxane has unit formula: (HR 4 2 SiO 1/2 ) g (R 4 3 SiO 1/2 ) h (R 4 2 SiO 2/2 ) i (HR 4 SiO 2/2 ) j , where subscripts g, h, i, and j have values such that g≥0, h≥0, a quantity (g+h) has an average value of 2, i≥0, j≥0, and a quantity (g+j)>0, a quantity (i+j) ranges from 0 to 1000, and the quantity (g+j) has a value sufficient to provide the polyorganohydrogensiloxane with at least 1% silicon bonded hydrogen atoms; and
each R 4 is an independently selected monovalent hydrocarbon group.

9. The method of claim 1 , further comprising: neutralizing residual boron-containing Lewis acid in the product.

10. The method of claim 1 , further comprising: during and/or after step 2), removing the by-product comprising HR 2 .

11. A method for preparing a functionalized polyorganosiloxane comprising:
1) combining starting materials comprising
5 ppm to 600 ppm, based on weight of starting material B), of A) a boron-containing Lewis acid, and
B) an organosilicon compound having an average, per molecule of at least 1 silicon bonded group of the formula —OR 2 ; wherein each R 2 is an independently selected monovalent hydrocarbon group of one to 6 carbon atoms, thereby forming a catalyzed mixture; and thereafter

2) adding the catalyzed mixture into starting materials comprising
C) an organohydrogensiloxane having at least 1 silicon bonded hydrogen atom per molecule, thereby preparing a product comprising the functionalized polyorganosiloxane and a by-product comprising HR 2 , and
5 ppm to 250 ppm, based on weight of C) the organohydrogensiloxane, of additional boron-containing Lewis acid.

12. The method of claim 11 , where step 2) is performed at a temperature of 5° C. to 40° C.

13. The method of claim 11 , where the method is performed at a temperature of 5° C. to 70° C.

14. The method of claim 11 , where the catalyzed mixture in step 1) is heated to 40° C. to 70° C. before step 2).

15. The method of claim 14 , where the catalyzed mixture is cooled to less than 40° C. in step 2).

16. The method of claim 11 , where the method is performed at a temperature of 10° C. to less than 25° C.

17. The method of claim 11 , where C) the organohydrogensiloxane has unit formula: (HR 4 2 SiO 1/2 ) g (R 4 3 SiO 1/2 ) h (R 4 2 SiO 2/2 ) (HR 4 SiO 2/2 ) j , where subscripts g, h, i, and j have values such that g≥0, h≥0, a quantity (g+h) has an average value of 2, i≥0, j≥0, and a quantity (g+j)>0, a quantity (i+j) ranges from 0 to 1000, and the quantity (g+j) has a value sufficient to provide the polyorganohydrogensiloxane with at least 1% silicon bonded hydrogen atoms; and each R 4 is an independently selected monovalent hydrocarbon group.

18. The method of claim 11 , further comprising: 3) neutralizing residual boron-containing Lewis acid in the product.

19. The method of claim 11 , further comprising: during and/or after step 2), removing the by-product comprising HR 2 .

20. The method of claim 11 , where the boron containing Lewis acid, and when present, and any additional boron containing Lewis acid, is provided in a total amount of 50 ppm to 6006000 ppm, based on combined weights of B) the organosilicon compound and C) the organohydrogensiloxane.

Assignees

• Dow Silicones Corp

Inventors

• Telgenhoff Michael
• Joffre Eric
• Liu Nanguo

Classifications

• C08G77/18

  to alkoxy or aryloxy groups · CPC title

• C08G77/12

  containing silicon bound to hydrogen · CPC title

• C08G77/08 Primary

  characterised by the catalysts used · CPC title

• C08L83/04

  Polysiloxanes · CPC title

• C08K5/55

  Boron-containing compounds {(C08K5/0091 takes precedence)} · CPC title