Process for the preparation of silylated polymers employing a backmixing step

Patent metadata

Field	Value
Publication number	US-9828459-B2
Application number	US-201514823588-A
Country	US
Kind code	B2
Filing date	Aug 11, 2015
Priority date	Aug 11, 2015
Publication date	Nov 28, 2017
Grant date	Nov 28, 2017

Abstract

A continuous process for preparing a silylated polymer comprising a silylation step where a prepolymer having reactive functional groups, a first intermediate product, is reacted continuously with a silylating agent in an endcapping tubular reaction unit to form a second intermediate product, and where at least a portion of the second intermediate product is backmixed continuously with the first intermediate product to form the silylated polymer. The continuous process may further comprise a stabilization step, a quenching step or both a stabilization step and a quenching step.

First claim

The invention claimed is:

1. A process for the preparation of a silylated polymer comprising
continuously reacting a prepolymer with a silylating agent, by a silylation reaction, to produce a silylated polymer composition; and
continuously backmixing at least a first portion of the silylated polymer composition with a loop connected from a downstream outlet to an upstream outlet of a reactor to adjust at least one upstream process parameter.

2. The process of claim 1 , wherein the silylated polymer composition comprises a fully silylated polymer and a partially silylated polymer.

3. The process of claim 1 , wherein a weight ratio of the first portion of the silylated polymer composition to the prepolymer ranges from about 0.05:1 to about 5:1.

4. The process of claim 1 , wherein the at least one upstream process parameter is at least one of residence time, temperature, weight ratio of the first portion to the prepolymer.

5. The process of claim 1 , wherein the prepolymer is a polyol with reactive functional groups or a chain extended prepolymer with reactive functional groups.

6. The process of claim 5 , wherein the reactive functional groups of either or both of the polyol and chain extended polymer are terminal reactive functional groups.

7. The process of claim 5 , wherein the chain extended prepolymer is prepared by continuously reacting a polyol with a chain extension agent.

8. The process of claim 1 further comprising continuously reacting at least a second portion of the silylated polymer composition with a scavenging agent or scavenging package to produce a quenched silylated polymer composition.

9. The process of claim 7 , wherein the chain extension agent is a diisocyanate or a polyisocyanate.

10. The process of claim 6 , wherein the terminal reactive functional groups are at least one of hydroxyl or isocyanate.

11. The process of claim 1 , wherein the silylating agent is an isocyanatosilane, mercaptosilane, hydroxyl-functional silane or an aminosilane.

12. The process of claim 1 , wherein the silylated polymer composition comprises a moisture-curable silylated polyurethane polymer.

13. The process of claim 8 , wherein the scavenging package comprises at least one cyclic amide scavenging agent.

14. The process of claim 13 , wherein the scavenging package further comprises a vinyltrimethoxysilane in a blend with the at least one cyclic amide scavenging agent.

15. The process of claim 13 , wherein the cyclic amide is selected from the group consisting of ε-caprolactam, 2-pyrrolidone and combinations thereof.

16. The process of claim 6 , wherein at least one of the terminal reactive functional groups is isocyanate and the silylating agent is an aminosilane.

17. The process of claim 6 , wherein at least one of the terminal reactive functional groups is a hydroxyl group and the silylating agent is an isocyanatosilane.

18. The process of claim 1 , further comprising adding a stabilization package to the process.

19. The process of claim 18 , wherein the stabilization package comprises at least one of a hindered phenol or phosphite stabilizer.

20. The process of claim 14 further comprising a stabilization package having triisodecyl phosphite.

Assignees

• Momentive Performance Mat Inc

Inventors

• Banevicius John
• Huang Misty
• O'Keefe Brendan
• Kumar Vikram
• Barbera Bruce

Classifications

• C08G18/08 Primary

  Processes · CPC title

• C08G18/10

  Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step · CPC title

• C08G18/718

  containing silicon · CPC title

• C08K5/524

  Esters of phosphorous acids, e.g. of H3PO3 · CPC title

• C08G18/289 Primary

  containing silicon · CPC title