Low-salt process for the preparation of a polysulfide

Patent metadata

Field	Value
Publication number	US-10179838-B2
Application number	US-201515534399-A
Country	US
Kind code	B2
Filing date	Dec 16, 2015
Priority date	Dec 17, 2014
Publication date	Jan 15, 2019
Grant date	Jan 15, 2019

Abstract

Process for the preparation of a polysulfide comprising the step of reacting in the absence of a dihaloalkane a bis(2-dihaloalkyl)formal in the presence of (i) a pre-polymer (I) according to structure (I)

X—(R2—O) n —CH2—O—(R1—O) m —CH2—(O—R2) p —X  (I),

wherein R1 and R2 can be the same or different and are selected from alkane chains containing 2-10 carbon atoms, X is a halogen atom, and n, m, and p are integers that can be the same or different and have a value in the range 1-6, with either (i) sodium polysulfide or (ii) a combination of sodium hydrosulfide and sulfur.

First claim

The invention claimed is:

1. Process for the preparation of a polysulfide comprising the step of reacting a bis(2-haloalkyl)formal with either (i) sodium polysulfide or (ii) a combination of sodium hydrosulfide and sulfur, the reaction being performed in the absence of a dihaloalkane and in the presence of a pre-polymer (I) according to structure (I)
X—(R 2 —O) n —CH 2 —O—(R 1 —O) m —CH 2 —(O—R 2 ) p —X  (I),

wherein R 1 and R 2 can be the same or different and are selected from alkane chains containing 2-10 carbon atoms, X is a halogen atom, and n, m, and p are integers that can be the same or different and have a value in the range 1-6.

2. Process according to claim 1 , wherein the bis(2-haloalkyl)formal is bis(2-chloroalkyl)formal.

3. Process according to claim 1 wherein the X is a halogen selected from Cl, Br, and I.

4. Process according to claim 3 wherein the X is Cl.

5. Process according to claim 1 , wherein the R 1 of the pre-polymer (I) is —CH 2 CH 2 —.

6. Process according to claim 1 , wherein the R 2 of the pre-polymer (I) is —CH 2 —CH 2 —, —CH 2 —CH 2 —CH 2 —, or —CH 2 —CH 2 —CH 2 —CH 2 —.

7. Process according to claim 1 , wherein the product resulting from the reaction of the bis(2-haloalkyl)formal with sodium polysulfide in the presence of the pre-polymer (I) is treated with a reduction agent to obtain a liquid polysulfide.

8. Process according to claim 1 , wherein the molar ratio of sodium polysulfide (calculated as Na 2 S x ) relative to the bis(2-haloalkyl)formal is in the range 0.8-1.4.

9. Process according to claim 1 , wherein a mixture comprising bis(2-haloalkyl)formal and the pre-polymer (I) is added to an aqueous solution of sodium hydrosulfide and sulfur.

10. Process according to claim 9 , wherein the aqueous solution has a temperature in the range of 60 to 100° C.

11. Process according to claim 1 , wherein the weight ratio of the bis(2-haloalkyl)formal to the pre-polymer (I) is in the range of 90:10 to 10:90.

12. Product obtained by the process according to claim 1 .

13. A composition comprising a product obtained by the process according to claim 1 , said composition selected from sealants, adhesives and coating compositions.

Assignees

• Akzo Nobel Chemicals Int Bv

Inventors

• Menzel Manfred
• Burkhardt Volker
• Klobes Olaf

Classifications

• C08G75/16 Primary

  by polycondensation of organic compounds with inorganic polysulfides · CPC title

• C07C43/315

  containing oxygen atoms singly bound to carbon atoms not being acetal carbon atoms · CPC title

• C08L81/04

  Polysulfides · CPC title

• C08G75/00 Primary

  Macromolecular compounds obtained by reactions forming a linkage containing sulfur with or without nitrogen, oxygen, or carbon in the main chain of the macromolecule · CPC title

• C08L81/02

  Polythioethers; Polythioether-ethers · CPC title